Uranium and plutonium extraction from fluoride melts by lithium-tin alloys

International Nuclear Information System (INIS)

Kashcheev, I.N.; Novoselov, G.P.; Zolotarev, A.B.

1975-01-01

Extraction of small amounts of uranium (12 wt. % concentration) and plutonium (less than 1.10sup(-10) % concentration) from lithium fluoride melts into the lithium-tin melts is studied. At an increase of temperature from 850 to 1150 deg the rate of process increases 2.5 times. At an increase of melting time the extraction rapidly enhances at the starting moment and than its rate reduces. Plutonium is extracted into the metallic phase for 120 min. (87-96%). It behaves analogously to uranium

Determination of uranium and plutonium in high active solutions by extractive spectrophotometry

International Nuclear Information System (INIS)

Subba Rao, R.V.; Damodaran, K.; Santosh Kumar, G.; Ravi, T.N.

2000-01-01

Plutonium and uranium was extracted from nitric acid into trioctyl phosphine oxide in xylene. The TOPO layer was analysed by spectrophotometry. Thoron was used as the chromogenic agent for plutonium. Pyridyl azoresorcinol was used as chromogenic agent for uranium. The molar absorption coefficient for uranium and plutonium was found to be 19000 and 19264 liter/mole-cm, respectively. The correlation coefficient for plutonium and uranium was found to be 0.9994. The relative standard deviation for the determination of plutonium and uranium was found to be 0.96% and 1.4%, respectively. (author)

Removal of plutonium from real time waste using supercritical fluid extraction

International Nuclear Information System (INIS)

Sujatha, K.; Sivaraman, N.; Kumar, R.; Srinivasan, T.G.; Vasudeva Rao, P.R.

2010-01-01

Supercritical fluid extraction (SFE) technique was carried out for the recovery of plutonium from cellulose waste matrix using supercritical carbon dioxide (SC-CO 2 ) modified with suitable ligands such as octylphenyl N,N-diisobutyl carbamoylmethyl phosphine oxide (φCMPO), tri-n-butyl phosphate (TBP), acetyl acetone, trifluoro acetyl acetone and theonyltrifluoroacetyl acetone (TTA). The maximum plutonium recovery was found to be 99.8% when SC-CO 2 modified with CMPO was employed. About 15mg of plutonium was recovered from waste. (author)

Fuel Cycle Impacts of Uranium-Plutonium Co-extraction

International Nuclear Information System (INIS)

Taiwo, Temitope; Szakaly, Frank; Kim, Taek-Kyum; Hill, Robert

2008-01-01

A systematic investigation of the impacts of uranium and plutonium co-extraction during fuel separations on reactor performance and fuel cycle has been performed. Proliferation indicators, critical mass and radiation source levels of the separation products or fabricated fuel, were also evaluated. Using LWR-spent-uranium-based MOX fuel instead of natural-uranium-based fuel in a PWR MOX core requires a higher initial plutonium content (∼1%), and results in higher Np-237 content (factor of 5) in the spent fuel, and less consumption of Pu-238 (20%) and Am-241 (14%), indicating a reduction in the effective repository space utilization. Additionally, minor actinides continue to accumulate in the fuel cycle, and thus a separate solution is required for them. Differences were found to be quite smaller (∼0.4% in initial transuranics) between the equilibrium cycles of advanced fast reactor cores using spent and depleted uranium for make-up, in additional to transuranics. The critical masses of the co-extraction products were found to be higher than for weapons-grade plutonium (WG-Pu) and the decay heat and radiation sources of the materials (products) were also found to be generally higher than for WG-Pu in the transuranics content range of 10% to 100% in the heavy-metal. (authors)

Solid-phase extraction of plutonium in various oxidation states from simulated groundwater using N-benzoylphenylhydroxylamine

International Nuclear Information System (INIS)

Perevalov, S.A.; Malofeeva, G.I.; Kuzovkina, E.V.; Spivakov, B.Ya.

2013-01-01

Solid-phase extraction of plutonium in different individual and mixed oxidation states from simulated groundwater (pH 8.5) was studied. The extraction of plutonium species was carried out in a dynamic mode using DIAPAK C16 cartridges modified by N-benzoylphenylhydroxylamine (BPHA). It was shown that the extent of recovery depends on the oxidation state of plutonium. The extraction of Pu(IV) was at the level of 98-99% regardless of the volume and flow-rate of the sample solution. Pu(V) was extracted by 90-95% and 75-80% from 10- and 100-mL aliquots of the samples, respectively, whereas the extraction of Pu(VI) did not exceed 45-50%. An equimolar mixture of Pu(IV), Pu(V), and Pu(VI) was extracted by 74%. The distribution coefficients (K d ) and kinetic exchange capacities (S) of plutonium in various oxidation states were measured. It was found that during the sorption process, Pu(V) was reduced to Pu(IV) by 80-90% after an hour-long contact with the solid phase. Pu(VI) is reduced to Pu(V) by 34% and to Pu(IV) by 55%. In the case of mixed-valent solution of plutonium, only Pu(V) and Pu(IV) were found in the effluents. (author)

Pressurization of Containment Vessels from Plutonium Oxide Contents

International Nuclear Information System (INIS)

Hensel, S.

2012-01-01

Transportation and storage of plutonium oxide is typically done using a convenience container to hold the oxide powder which is then placed inside a containment vessel. Intermediate containers which act as uncredited confinement barriers may also be used. The containment vessel is subject to an internal pressure due to several sources including; (1) plutonium oxide provides a heat source which raises the temperature of the gas space, (2) helium generation due to alpha decay of the plutonium, (3) hydrogen generation due to radiolysis of the water which has been adsorbed onto the plutonium oxide, and (4) degradation of plastic bags which may be used to bag out the convenience can from a glove box. The contributions of these sources are evaluated in a reasonably conservative manner.

Simultaneous determinations of uranium, thorium, and plutonium in soft tissues by solvent extraction and alpha-spectrometry

International Nuclear Information System (INIS)

Singh, N.P.; Zimmerman, C.J.; Lewis, L.L.; Wrenn, M.E.

1984-01-01

A radiochemical procedure for the simultaneous determination of uranium, thorium, and plutonium, in soft tissues has been developed. The weighed amounts of tissues, spiked with 232 U, 242 Pu, and 229 th tracers, are wet ashed. Uranium, thorium, and plutonium are coprecipitated with iron as hydroxides, dissolved in concentrated HCl and the acidity adjusted to 10 M. Uranium and plutonium are extracted into 20% TLA solution in xylene, leaving thorium in the aqueous phase. Plutonium is back-extracted by reducing to the trivalent state with 0.05 M NH 4 I solution in 8 M HCl, and uranium is back-extracted with 0.1 M HCl. Thorium is extracted into 20% TLA solution from 4 M HNO 3 and back-extracted with 10 M HCl. Uranium, thorium and plutonium are electrodeposited separately onto platinum discs and counted alpha-spectrometrically using surface barrier silicon diodes and a multichannel analyzer. The method was developed using bovine liver and applied to dog and human tissues. The mean radiochemical recoveries of these actinides in different organs were better than 70%. 6 references, 2 tables

Gamma-radiolysis of organic compounds and alpha-radiolysis of water

International Nuclear Information System (INIS)

Christensen, H.

1978-09-01

This KBS-report is a collection of five technical reports. Various radiolytic problems in connection with the disposal of high-active waste are dealt with. The English titles of the five reports are: 1) Radiolysis of fulvic acids; 2) Radiolysis of organic compounds in bentonite; 3) α-radiolysis of water during the disposal of fuel without reprocessing; 4) Radiolysis of water during the disposal of unreprocessed spent fuel. Oxidation by hydrogen peroxide; 5) Formation and decomposition of hydrogen peroxide by α-radiolysis. These reports (in Swedish) are attached as Appendices A-E. (author)

Self-Radiolysis of Tritiated Water: Experimental Study and Simulation

International Nuclear Information System (INIS)

Heinze, Sylver; Stolz, Thibaut; Ducret, Didier; Colson, Jean-Claude

2005-01-01

Radioactive decay of tritium contained in tritiated water leads to the production of gaseous helium and, through self-radiolysis, to the formation of molecular hydrogen and oxygen. For safety management of tritiated water storage, it is essential to be able to predict pressure increase resulting from this phenomenon. The present study aims to identify the mechanisms that take place in self-radiolysis of chemically pure liquid tritiated water. The evolution of the concentration of hydrogen and oxygen in the gas phase of closed vessels containing tritiated water has been followed experimentally. Simulation of pure water radiolysis has been carried out using data from the literature. In order to fit experimental results, simulation should take into account gas phase recombination reaction between hydrogen and oxygen. A simplified system has been extracted from the complete chemical system used to simulate radiolysis. This system allows identifying the basic mechanisms that are responsible for tritiated water self-radiolysis

Uranium decontamination in Purex second plutonium cycle: An example of solvent extraction modeling

International Nuclear Information System (INIS)

Hsu, T.C.

1986-01-01

The existing Purex flowsheet used in the second plutonium cycle at the Savannah River Plant (SRP) does not remove uranium from the plutonium stream. To develop new flowsheets for the Purex second plutonium cycle, computer simulation using SEPHIS was used. SEPHIS is an ORNL-developed solvent extraction simulation code. Box-Wilson experimental design was used to select the minimum set of process conditions simulated. The calculated results were plotted into three-dimensional response surfaces by SAS/Graph (statistical analysis systems). These surfaces provide a broad and complete overview of the responses. Specific ranges of key variables were then investigated. The second series of process simulations identified flowsheets that provide high uranium decontamination while meeting all other key process requirements. The proposed flowsheet consists of modifying the existing 2B bank flowsheet by relocating the feed, increasing the extractant acidity, and adding a scrub stream. The nuclear safety issue was also examined

Summary of TRUEX Radiolysis Testing Using the INL Radiolysis Test Loop

Energy Technology Data Exchange (ETDEWEB)

Dean R. Peterman; Lonnie G. Olson; Rocklan G. McDowell; Gracy Elias; Jack D. Law

2012-03-01

The INL radiolysis and hydrolysis test loop has been used to evaluate the effects of hydrolytic and radiolytic degradation upon the efficacy of the TRUEX flowsheet for the recovery of trivalent actinides and lanthanides from acidic solution. Repeated irradiation and subsequent re-conditioning cycles did result in a significant decrease in the concentration of the TBP and CMPO extractants in the TRUEX solvent and a corresponding decrease in americium and europium extraction distributions. However, the build-up of solvent degradation products upon {gamma}-irradiation, had little impact upon the efficiency of the stripping section of the TRUEX flowsheet. Operation of the TRUEX flowsheet would require careful monitoring to ensure extraction distributions are maintained at acceptable levels.

Analysis of low-molecular weight radiolysis products in extracts of gamma-irradiated polymers by gas chromatography and high-performance liquid chromatography

International Nuclear Information System (INIS)

Buchalla, Rainer; Begley, Timothy H.; Morehouse, Kim M.

2002-01-01

Estimating exposure to radiolysis products of polymers is an important part of the regulatory evaluation of packaging materials for use in food irradiation. However, as Koni Grob recently put it, the comprehensive analysis of migrants is a challenge. This paper discusses some of the analytical difficulties and presents results obtained with extracts of irradiated polystyrene and polyamide-6. The results indicate that headspace or thermal desorption techniques may, in some instances, lead to an overestimation of radiolysis product concentrations. It is concluded that validated analytical methods and a better understanding of the underlying radiation chemistry would greatly facilitate the safety assessment of irradiated packaging materials

Gamma radiolysis of the highly selective ligands CyMe_4BTBP and CyMe_4BTPhen: Qualitative and quantitative investigation of radiolysis product

International Nuclear Information System (INIS)

Schmidt, H.; Wilden, A.; Modolo, G.; Bosbach, D.; Santiago-Schuebel, B.; Hupert, M.; Svehla, J.; Gruner, B.; Ekberg, C.

2016-01-01

The highly selective nitrogen donor ligands CyMe_4BTBP and CyMe4_BTPhen where γ-irradiated under identical experimental conditions in 1-octanol with and without contact to nitric acid solution. Subsequently, solvent extraction experiments were carried out to evaluate the stability of the extractants against γ-radiation monitoring Am(III) and Eu(III) distribution ratios. Generally, decreasing distribution ratios with increasing absorbed dose were detected for both molecules. Furthermore, qualitative mass spectrometric analyses were performed and ligand concentrations were determined by HPLC-DAD after irradiation to investigate the radiolysis mechanism. An exponential decrease with increasing absorbed dose was observed for both ligands with a faster rate for CyMe_4BTPhen. Main radiolysis products indicated the addition of one or more diluent molecules (1-octanol) to the ligand via prior production of α-hydroxy-octyl radicals from diluent radiolysis. The addition of nitric acid during the irradiation lead to a remarkable stabilization of the system, as the extraction of Am(III) and Eu(III) did not change significantly over the whole examined dose range. Quantification of the remaining ligand concentration on the other hand showed decreasing concentrations with increasing absorbed dose. The stabilization of D values is therefore explained by the formation of 1-octanol addition products which are also able to extract the studied metal ions. (authors)

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

Alpha Radiolysis of Nuclear Solvent Extraction Ligands Used for An(III) and Ln(III) Separations

Energy Technology Data Exchange (ETDEWEB)

Mezyk, Stephen P. [California State Univ. (CalState), Long Beach, CA (United States); Mincher, Bruce J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Nilsson, Mikael [Univ. of California, Irvine, CA (United States)

2016-08-01

This document is the final report for the Nuclear Energy Universities Program (NEUP) grant 10-910 (DE-AC07-05ID14517) “Alpha Radiolysis of Nuclear Solvent Extraction Ligands used for An(III) and Ln(III) Separations”. The goal of this work was to obtain a quantitative understanding of the impacts of both low Linear Energy Transfer (LET, gamma-rays) and high LET (alpha particles) radiation chemistry occurring in future large-scale separations processes. This quantitative understanding of the major radiation effects on diluents and ligands is essential for optimal process implementation, and could result in significant cost savings in the future.

Extraction of hexavalent uranium, tetravalent plutonium and fission products by N, N'-tetraalkyldiamides

International Nuclear Information System (INIS)

Charbonnel, M.C.

1988-10-01

This study deals with the extractive properties of N, N'-tetraalkylglutaramides of generic formula R 2 NC(0)(CH 2 ) 3 C(0)NR 2 . These molecules were considered as alternative extractants to tributylphosphate in nuclear fuels reprocessing. They are selective extractants of uranium and plutonium as far as trivalent actinides and lanthanides remain in aqueous nitric solutions. Distribution ratios measurements and F.T. Infra-Red investigations show that HN0 3 extraction takes place via the formation of the following species: 2L.HN0 3 , L.HN0 3 and L.2HN0 3 in the organic phase (L: glutaramide). Distribution ratios of actinide ions followed by UV-visible spectroscopy and Infra-Red investigations agree with formation of the following neutral organometallic complexes in low nitric acidity conditions: L.U0 2 (N0 3 ) 2 and L.Pu(N0 3 ) 4 and the anionic species at higher acidities: L.U0 2 (N0 3 ) 3 H and L.Pu(N0 3 ) 6 H 2 . Interactions occur through neutral complexes and free molecules of diamides which explain the non ideality of the organic phase. Degradation products of these molecules don't seem to alter the extractive properties of these extractants towards uranium and plutonium [fr

Gamma radiolysis of the highly selective ligands CyMe{sub 4}BTBP and CyMe{sub 4}BTPhen: Qualitative and quantitative investigation of radiolysis product

Energy Technology Data Exchange (ETDEWEB)

Schmidt, H.; Wilden, A.; Modolo, G.; Bosbach, D. [Forschungszentrum Juelich GmbH, Institute of Energy and Climate Research IEK-6: Nuclear Waste Management, 52425 Juelich (Germany); Santiago-Schuebel, B.; Hupert, M. [Forschungszentrum Juelich GmbH, Central Institute for Engineering, Analytics - ZEA-3, 52425 Juelich (Germany); Svehla, J.; Gruner, B. [Institute of Inorganic Chemistry, Academy of Sciences, Hlavni 1001, 25068 Husinec-Rez (Czech Republic); Ekberg, C. [Department of Chemical and Biochemical Engineering, Chalmers University of Technology, 41296 Gothenburg (Sweden)

2016-07-01

The highly selective nitrogen donor ligands CyMe{sub 4}BTBP and CyMe4{sub B}TPhen where γ-irradiated under identical experimental conditions in 1-octanol with and without contact to nitric acid solution. Subsequently, solvent extraction experiments were carried out to evaluate the stability of the extractants against γ-radiation monitoring Am(III) and Eu(III) distribution ratios. Generally, decreasing distribution ratios with increasing absorbed dose were detected for both molecules. Furthermore, qualitative mass spectrometric analyses were performed and ligand concentrations were determined by HPLC-DAD after irradiation to investigate the radiolysis mechanism. An exponential decrease with increasing absorbed dose was observed for both ligands with a faster rate for CyMe{sub 4}BTPhen. Main radiolysis products indicated the addition of one or more diluent molecules (1-octanol) to the ligand via prior production of α-hydroxy-octyl radicals from diluent radiolysis. The addition of nitric acid during the irradiation lead to a remarkable stabilization of the system, as the extraction of Am(III) and Eu(III) did not change significantly over the whole examined dose range. Quantification of the remaining ligand concentration on the other hand showed decreasing concentrations with increasing absorbed dose. The stabilization of D values is therefore explained by the formation of 1-octanol addition products which are also able to extract the studied metal ions. (authors)

Radiolysis of chitosan derivatives exhibiting antimutagenic activity

International Nuclear Information System (INIS)

Aleksandrova, V.A.; Kuzina, S.I.; Shilova, I.A.; Mikhajlov, A.I.

2006-01-01

The radiolysis of antimutagens extracted from natural biopolymer chitosan was studied by the EPR. The radiolysis of test samples of biopolymers and gallic acid was performed in vacuum at 77 K using a 60 Co γ-radiation source, with radiation doses 50 kGy. It was shown that addition of gallic acid (2 mol %) to quaternized chitosan results in a 2.5-fold decrease in the radiation-chemical yield of radicals and a nearly complete inhibition of the formation of ion radicals. Gallic acid units likely play the role of a stabilizer that protects the polycation from radiation damage and, hence, the structure of the cationogenic units from changes, thereby improving the antimutagenic properties of the system [ru

Progress on laboratory studies of the immobilisation of plutonium contaminated materials (pcm)

International Nuclear Information System (INIS)

Awmack, A.F.; Hemingway, K.

1984-09-01

This report describes progress on laboratory scale investigations into immobilisation of Plutonium Contaminated Materials for the year ending August 1984. The work is a continuation of that previously reported though some new work is also included. The samples tested were shredded plastic materials and latex. Three areas of work are covered (1) ISO Leach Tests (2) Radiolysis and degradation of organic materials (3) Equilibrium Leach Tests. (author)

Some studies on the extraction of plutonium from phosphate containing nitric acid solutions using DBDECMP as extractant

International Nuclear Information System (INIS)

Sagar, V.B.; Oak, M.S.; Pawar, S.M.; Sivaramakrishnan, C.K.; Patil, S.K.

1991-01-01

Extraction studies have been carried out to explore the feasibility of separation of Pu(IV) from phosphate containing analytical wastes generated in the laboratory. Distribution data on the extraction of Pu(IV) from DBDECMP (di-butyl,N,N-diethylcarbamoyl methyl phosphonate) in xylene an aqueous nitric acid and its mixture with sulfuric as well as with sulfuric and phosphoric acids were obtained. Based on the data obtained, the conditions for the recovery of plutonium from such water solutions are suggested. (author) 7 refs.; 1 fig.; 3 tabs

Plutonium-236 traces determination in plutonium-238 by α spectrometry

International Nuclear Information System (INIS)

Acena, M.L.; Pottier, R.; Berger, R.

1969-01-01

Two methods are described in this report for the determination of plutonium-236 traces in plutonium-238 by a spectrometry using semi-conductor detectors. The first method involves a direct comparison of the areas under the peaks of the α spectra of plutonium-236 and plutonium-238. The electrolytic preparation of the sources is carried out after preliminary purification of the plutonium. The second method makes it possible to determine the 236 Pu/ 238 Pu ratio by comparing the areas of the α peaks of uranium-232 and uranium-234, which are the decay products of the two plutonium isotopes respectively. The uranium in the source, also deposited by electrolysis, is separated from a 1 mg amount of plutonium either by a T.L.A. extraction, or by the use of ion-exchange resins. The report ends with a discussion of the results obtained with plutonium of two different origins. (authors) [fr

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

Radiolysis aspects of the aqueous self-cooled blanket concept and the problem of tritium extraction

International Nuclear Information System (INIS)

Bruggeman, A.; Snykers, M.; DeRegge, P.; Embrechts, M.J.

1988-01-01

In the Aqueous Self-Cooled Blanket (ASCB) concept, an aqueous 6 Li solution in a metallic structure is used as a fusion reactor shielding-breeding blanket. Radiolysis effects could be very important for the design and the use of an ASCB. Although many aspects of the radiation chemistry of water and dilute aqueous solutions are now reasonably well understood, it is not possible to predict the radiochemical behaviour of the concentrated candidate ASCB solutions quantitatively. However, by means of a worst case calculation for a possible ASCB for the Next European Torus (NET) it is shown that even with an important rate of water decomposition the ASCB concept is still workable. Gas bubbles and explosive mixtures can be avoided by increasing the pressure in the neutron irradiated zone and by extracting and/or recombining the radiolytically produced hydrogen and oxygen. This could require an additional inert gas loop, which could also be used as part of the tritium extraction installation

Study of the physico-chemical agents influencing uranium and plutonium extraction by tributylphosphate in nitric media; Etude des facteurs physico-chimiques intervenant dans l'extraction de l'uranium et du plutonium par le phosphate de tributyle en milieu nitrique

Energy Technology Data Exchange (ETDEWEB)

Tarnero, M [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1967-03-01

The following different factors are reviewed: tributylphosphate concentration, nitric acid concentration, influence of non-extractable nitrates, simultaneous presence of uranium and plutonium, presence of some different ions, temperature, nature of the diluent, addition of a second active solvent (synergic or antagonistic effect), tributylphosphate and diluent degradation. (author) [French] On passe en revue les differents facteurs suivants: concentration en phosphate de tributyle, concentration en acide nitrique, influence des nitrates non-extractibles, presence simultanee d'uranium et de plutonium, presence d'ions divers, addition d'un second solvant actif (effet de synergie, ou effet antagoniste), degradation du phosphate de tributyle et des solvants inertes. (auteur)

The first metallurgical tests on plutonium; Premiers essais metallurgiques sur le plutonium

Energy Technology Data Exchange (ETDEWEB)

Grison, E; Abramson, R; Anselin, F; Monti, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

Metallic plutonium was first prepared in France in January 1956, as soon as we had access to quantities of the order of several grams of plutonium, which had been extracted from the rods of the pile EL2 at Saclay. Since up to the present this reactor, of thermal power 2 000 kW, has been our only source of plutonium, we have so far only worked on experimental quantities sufficient for the basic tests but not for tests on a scale of possible applications. It is this work, carried out during this phase of preliminary research, which is described below. With the starting up of the plutonium extraction plant at Marcoule, where the reactor G1 has been operating at power for more than a year, we shall go on next to a another order of magnitude which will allow the manufacture and experimentation of prototype fuel elements. (author) [French] La premiere elaboration de plutonium metallique en France fut faite en janvier 1956, des que nous pumes disposer de quantites de plutonium de l'ordre de quelques grammes, qui avaient ete retires des barreaux de la pile EL2 de Saclay. Ce reacteur, d'une puissance thermique de 2 000 kW, ayant ete jusqu'a present notre seule source de plutonium, nous n'avons encore travaille que sur des quantites experimentales suffisantes pour les essais de base, mais non pour des essais a l'echelle d'applications possibles. Ce sont les travaux effectues pendant cette phase de recherches preliminaires qui seront evoques ci-dessous. Avec la mise eu route de l'usine d'extraction de plutonium de Marcoule, ou le reacteur G1 fonctionne en puissance depuis plus d'un an, nous allons passer prochainement a un autre ordre de grandeur, qui nous permettra la fabrication et l'experimentation d'elements combustibles prototypes. (auteur)

Radiolysis of spray solutions

International Nuclear Information System (INIS)

Habersbergerova, A.; Janovsky, I.

1985-01-01

The factors were studied affecting thiosulfate radiolysis in the so-called spray solution for nuclear power plant containments. The reaction mechanism of primary radiolytic reactions leading to thiosulfate decomposition was studied using pulse radiolysis. Also measured was hydrazine loss in the irradiation of the bubbling solution intended for the capture of volatile chemical forms of radioiodine. Pulse radiolysis was used to study the kinetics of hydrazine reaction with elemental iodine. (author)

Assesment of Plutonium 238 and Plutonium 239+240 in soils of different agricultural regions of Guatemala

International Nuclear Information System (INIS)

Gutierrez Martinez, E.A.

1998-02-01

In this report an assesment and measurement of PLUTONIUM 238, PLUTONIUM 239, and PLUTONIUM 240 are made. Samples of cultivated soils in 15 provinces of Guatemala were taken. To separate plutonium isotopes a radiochemical method was made using extraction, precipitation and ionic interchange. By electrodeposition the plutonium was measured using an alpha spectroscopy by PIPS method. The radioactivity ranges from 2.84 mBq/Kg to 36.38 mBq/Kg for plutonium 238, and 8.46 mBq/Kg to 26.61 mBq/Kg for plutonium 239+240

The handling of plutonium hexafluoride (1962); Manipulation de l'hexafluorure de plutonium (1962)

Energy Technology Data Exchange (ETDEWEB)

Berard, Ph [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1961-11-15

The major problem posed in this work is the instability of plutonium hexafluoride. The influence of various factors on the decomposition of the fluoride has been studied: physical aspect of the walls, nature of the metal and its pretreatment, influence of the temperature. A means of detecting plutonium-239 in a metallic apparatus by {gamma}-ray counting has been developed; the sensitivity is of the order of half a milligram, but the precision is very low (about 50 per cent). Yields of over 95 per cent have been obtained for the transfer of plutonium during the preparation and sublimation of the hexafluoride. This study confirms the possibility of using plutonium hexafluoride for the extraction of plutonium from irradiated fuel elements by a dry method. (author) [French] Le probleme majeur de cette etude a ete l'instabilite de l'hexafluorure de plutonium. Nous avons etudie l'influence de divers facteurs sur la decomposition de l'hexafluorure: aspect physique des parois, nature du metal et de son pretraitement, influence de la temperature. Nous avons mis au point un mode de detection du plutonium-239 dans un appareillage metallique par comptage du rayonnement {gamma}; la sensibilite est de l'ordre du demi-milligramme, mais la precision est tres faible (50 pour cent environ). Nous avons obtenu des rendements depassant 95 pour cent dans le transfert du plutonium au cours de la fabrication et de la sublimation de l'hexafluorure. Cette etude confirme la possibilite d'utiliser l'hexafluorure de plutonium dans l'extraction du plutonium des combustibles irradies par voie seche. (auteur)

Non-gaseous radiolysis products of 6-aminopenicillanic acid and potassium salt of benzylepenicillin

International Nuclear Information System (INIS)

Dziegielewski, J.; Jezowska-Trzebiatowska, B.; Siemion, I.Z.

1974-01-01

The radiolysis products of 6-aminopenicillanic acid (6-APA) and potassium salt of benzylpenicillin G, irradiated with γ-rays were separated by the extraction methods and chromatographically by the thin-layer method. On the basis of the IR and UV spectroscopic investigations as well as by the NMR and mass spectrometry methods of the radiolysis products, the paths of the radiation decomposition of 6-APA and of penicillin G were determined. (author)

Extraction of plutonium from phosphate containing nitric acid solutions using DHDECMP as extractant (Preprint no. SSC-03)

International Nuclear Information System (INIS)

Sagar, V.B.; Pawar, S.M.; Joshi, A.R.; Kasar, U.M.; Sivaramkrishnan, C.K.

1991-01-01

Distribution data for the extraction of Pu(IV) by DHDECMP (Di-hexyl, N-N-diethylcarbamoylmethylphosphonate) in xylene from aqueous nitric acid and its mixtures with sulphuric acid and phosphoric acid were obtained to explore the feasibility of recovery of Pu(IV) from analytical waste generated in the laboratory. Based on the data obtained, conditions for recovery of plutonium are suggested. (author). 3 refs., 3 tabs

Fractionation of plutonium in environmental and bio-shielding concrete samples using dynamic sequential extraction

DEFF Research Database (Denmark)

Qiao, Jixin; Hou, Xiaolin

2010-01-01

Fractionation of plutonium isotopes (238Pu, 239,240Pu) in environmental samples (i.e. soil and sediment) and bio-shielding concrete from decommissioning of nuclear reactor were carried out by dynamic sequential extraction using an on-line sequential injection (SI) system combined with a specially...

The first milligrams of plutonium

International Nuclear Information System (INIS)

Goldschmidt, B.

1996-01-01

This paper relates the discovery of the different plutonium chemical extraction processes in their historical context. The first experiments started during the second world war in 1942 with the American ''Metallurgical Laboratory'' project which brought together Arthur Compton, Enrico Fermi and Glenn Seaborg. During the same period, a competitive English-Canadian project, the ''Montreal Project'', was carried out to test different plutonium solvent extraction techniques. The author participated in both projects and joined the CEA in 1946, where he was in charge of the uranium and plutonium chemistry. By the end of 1949, his team could isolate the first milligrams of French plutonium from uranium oxide pellets of the ZOE reactor. In the beginning of 1952 he developed with his team the PUREX process. (J.S.)

Radical intermediates of low temperature radiolysis of di-tert-butylcyclohexano-18-crown-6/1-octanol extractant

International Nuclear Information System (INIS)

Zakurdaeva, O.A.; Nesterov, S.V.; Moscow State Univ.; Feldman, V.I.

2013-01-01

Intermediates of low temperature (77 K) X-rays radiolysis of 1-octanol and di-tert-butylcyclohexano-18-crown-6 solutions in 1-octanol were studied by ESR spectroscopy. Hydroxyalkyl CH 3 (CH 2 ) 6 C circle HOH and interior-type alkyl R 1 C circle HR 2 OH radicals were found to be main paramagnetic products stabilized in 1-octanol irradiated at 77 K. In addition to abovementioned radicals, macrocyclic -O-CH 2 -C circle H- and acyclic -C circle H-C(H)=O radicals produced from crown ether were identified in irradiated 1.0 M DtBuCH18C6 solution in octanol. No deviation in radiation-chemical yield of the stabilized acyclic radicals from the value expected in accord with 'additive' rule was observed in the latter case. It was supposed that macrocycle cleavage in DtBuCH18C6 occurred at early stages of radiolysis rather than in secondary radical reactions between products of 1-octanol radiolysis and crown ether. Meanwhile, alkyl radicals formed from 1-octanol can react with crown ether, resulting in formation of macrocyclic products of radiolysis. (orig.)

Radical intermediates of low temperature radiolysis of di-tert-butylcyclohexano-18-crown-6/1-octanol extractant

Energy Technology Data Exchange (ETDEWEB)

Zakurdaeva, O.A.; Nesterov, S.V. [Russian Academy of Sciences, Moscow (Russian Federation). Enikolopov Institute of Synthetic Polymer Materials; Moscow State Univ. (Russian Federation). Dept. of Chemistry; Feldman, V.I. [Moscow State Univ. (Russian Federation). Dept. of Chemistry

2013-03-01

Intermediates of low temperature (77 K) X-rays radiolysis of 1-octanol and di-tert-butylcyclohexano-18-crown-6 solutions in 1-octanol were studied by ESR spectroscopy. Hydroxyalkyl CH{sub 3}(CH{sub 2}){sub 6}C {sup circle} HOH and interior-type alkyl R{sub 1}C {sup circle} HR{sub 2}OH radicals were found to be main paramagnetic products stabilized in 1-octanol irradiated at 77 K. In addition to abovementioned radicals, macrocyclic -O-CH{sub 2}-C {sup circle} H- and acyclic -C {sup circle} H-C(H)=O radicals produced from crown ether were identified in irradiated 1.0 M DtBuCH18C6 solution in octanol. No deviation in radiation-chemical yield of the stabilized acyclic radicals from the value expected in accord with 'additive' rule was observed in the latter case. It was supposed that macrocycle cleavage in DtBuCH18C6 occurred at early stages of radiolysis rather than in secondary radical reactions between products of 1-octanol radiolysis and crown ether. Meanwhile, alkyl radicals formed from 1-octanol can react with crown ether, resulting in formation of macrocyclic products of radiolysis. (orig.)

Primary processes during water radiolysis

International Nuclear Information System (INIS)

Pikaev, A.K.

1980-01-01

Briefly reviewed are investigations of primary process mechanism taking place during radiolysis of water and similar systems, executed by direct and indirect methods. A conclusion is made on the important role of the water structure during radiolysis of aqueous solutions of some substances. A necessity to take account of this factor during consideration of radiolysis theoretical models is pointed out

Solvent extraction process development for high plutonium fuel cycles

Energy Technology Data Exchange (ETDEWEB)

Anil Kumar, R; Selvaraj, P G; Natarajan, R; Raman, V R [Reprocessing Group, Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

1994-06-01

The purification of high plutonium bearing irradiated fuels using 30% TBP in dodecane diluent requires precise determination of concentration profiles during steady state, transient and process upset conditions. Mathematical models have been developed and a computer code is in use for determining Pu-U concentration profiles in a solvent extraction equipment in a typical reprocessing plant. The process parameters have been optimised for recovery of U and Pu and decontamination from the fission products. This computer code is used to analyse the extraction flow sheets of fuels of two typical Pu-U compositions encountered in Indian fast breeder programme. The analysis include the effect of uncertainty in equilibrium condition prediction by the model and the variation of flows of streams during plant operation. The studies highlight the margin available to avoid second organic phase formation and adjustments required in the process flowsheet. (author). 7 refs., 7 figs., 2 tabs.

Materials identification and surveillance project item evaluation: Items, impure plutonium oxide (ATL27960) and pure plutonium oxide (PEOR3258)

International Nuclear Information System (INIS)

Allen, T.; Appert, Q.; Davis, C.

1997-03-01

In this report, Los Alamos scientists characterize properties relevant to storage of an impure plutonium oxide (74 mass % plutonium) in accordance with the Department of Energy (DOE) standard DOE-STD-3013-96. This oxide is of interest because it is the first impure plutonium oxide sample to be evaluated and it is similar to other materials that must be stored. Methods used to characterize the oxide at certain points during calcination include surface-area analyses, mass loss-on-ignition (LOI) measurements, elemental analysis, moisture-adsorption measurements, and quantitative supercritical-CO 2 extraction of adsorbed water. Significant decreases in the LOI and surface area occurred as the oxide was calcined at progressively increasing temperatures. Studies indicate that supercritical-CO 2 extraction is an effective method for removing adsorbed water from oxides. We extracted the water from powdered oxides (high-purity ZrO 2 , pure PuO 2 , and impure plutonium oxide) using CO 2 at 3000 psi pressure and 75 degrees C, and we quantitatively determined it by using gravimetric and dew-point procedures. The effectiveness of the extraction method is demonstrated by good agreement between the amounts of water extracted from pure zirconium and plutonium dioxides and the mass changes obtained from LOI analyses. However, the amount of moisture (0.025 mass %) extracted from the impure plutonium oxide after it had been calcined at 950 degrees C and stored for a period of months is much less than the LOI value (0.97 mass %). These results imply that the impure plutonium oxide is free of adsorbed water after calcination at 950 degrees C, even though the sample does not satisfy the LOI requirement of <0.50 mass % for storage

Extraction of plutonium(IV) by bis(2-ethylhexyl) sulfoxide: a novel branched-chain extractant (Preprint No. ST.23)

International Nuclear Information System (INIS)

Shukla, J.P.; Kedari, C.S.

1989-01-01

Di-n-alkyl sulfoxides offer certain distint advantages over other common extractants for use in actinides separation particularly in the presence of high radiation fields. Despite widespread interest in these extractants, practical applications of such sulfoxides in nuclear fuel reprocessing have been seriously hampered owing to their poor solubility in common aliphatic hydrocarbon diluents. Recently a promising new branched-chain sulfoxide extractant, bis( 2-ethylhexyl) sulfoxide (BESO) has been introduced as a novel extracting agent for uranium. It possesses almost all the advantages of other sulfoxides, but excels the rest in terms of its complete miscibility with dodecane and the highest Ksub(H) value reported for any sulfoxide. As a part of comprehensive program to explore its analytical usefulness, data concerning preliminary studies on the extraction of plutonium with BESO form nitric acid solutions are reported. (author)

Distribution and identification of Plutonium(IV) species in tri-n-butyl phosphate/HNO3 extraction system containing acetohydroxamic acid

International Nuclear Information System (INIS)

Tkac, P.; Paulenova, A.; Vandegrift, G.F.; Krebs, J.F.

2009-01-01

There was a significant research progress achieved with the aim to modify conventional PUREX process by stripping of plutonium from the tri-n-butyl phosphate (TBP) extraction product in the form of non-extractable complexes upon addition of back-hold complexation agents. The present paper reports effects of such salt-free complexant, acetohydroxamic acid (HAHA), on distribution ratio of Pu(IV) under wide concentration of nitric acid and additional nitrate. General formula of plutonium species present in the organic phase can be described as Pu(OH) x (AHA) y (NO3) 4-x-y x 2TBP x wHNO 3 . (author)

Liquid-liquid extraction of plutonium and americium by cekanoic acid from alkaline medium

International Nuclear Information System (INIS)

Venugopal Chetty, K.; Sagar, V.; Swarup, R.

2001-01-01

Liquid-liquid extraction studies of plutonium and americium from aqueous carbonate medium using a high molecular weight carboxylic acid namely cekanoic acid in different diluents has been carried out. The distribution ratio (D) values for Pu(IV) and Am(III) under various parameters such as concentration of extractant, Na 2 CO 3 and initial pH were obtained. Results indicated that Pu(IV) and Am(III) could be satisfactorily extracted together or individually from aqueous carbonate medium using cekanoic acid in different diluents like carbon tetrachloride, cyclohexane, toluene, n-dodecane or solvesso-100. The D values for Pu(IV) and Am(III) also indicated the possibility of their mutual separation. The back extraction of Pu and Am with different reagents was also studied. (orig.)

Gamma-radiolysis of benzosubstituted crown ethers

International Nuclear Information System (INIS)

Grigor'ev, E.I.; Nesterov, S.V.; Mikhalitsyna, O.V.; Trakhtenberg, L.I.; Myasoedova, T.G.

1992-01-01

The products of gamma-radiolysis of benzosubstituted crown ethers, which are distiguished by the size of polyether ring, and alkylsubstituted DB18C6 are studied by the methods of ESR and mass-spectrometry. A mechanism of the radiolysis of the radiolysis of the studied compounds in the solid phase is proposed. It is shown that the prinicple radiolysis process is the rupture of C-O bond resulting in the stabilization of H atoms from group -CH 2 - of polyether ring is realized with a lower probability

Factors Controlling Redox Speciation of Plutonium and Neptunium in Extraction Separation Processes

Energy Technology Data Exchange (ETDEWEB)

Paulenova, Alena [Principal Investigator; Vandegrift, III, George F. [Collaborator

2013-09-24

The objective of the project was to examine the factors controlling redox speciation of plutonium and neptunium in UREX+ extraction in terms of redox potentials, redox mechanism, kinetics and thermodynamics. Researchers employed redox-speciation extractions schemes in parallel to the spectroscopic experiments. The resulting distribution of redox species w studied uring spectroscopic, electrochemical, and spectro-electrochemical methods. This work reulted in collection of data on redox stability and distribution of redox couples in the nitric acid/nitrate electrolyte and the development of redox buffers to stabilize the desired oxidation state of separated radionuclides. The effects of temperature and concentrations on the redox behavior of neptunium were evaluated.

Detection of {alpha} particles using semiconductors. Application to the control of plutonium extraction; Detection des particules {alpha} par semiconducteurs application au controle de l'extraction du plutonium

Energy Technology Data Exchange (ETDEWEB)

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

1968-03-01

A study is made of a particles produced by thick sources, using either diffused junction or surface barrier semiconductor detectors for controlling continuously the plutonium extraction process. For this, a presenting apparatus is described in which the solutions to be analyzed flow in contact with the detector protected by a thin mica membrane. A method is described which gives a precise recording of the spectra and which thus allows the separation of two or more {alpha} emitters present in the same solution. This method has been applied to the measurement of {sup 239}Pu in the the presence of {sup 241}Am with an accuracy of {+-}5 per cent. In the second part of the report is considered the detection of plutonium in solutions of {beta} - {gamma} emitting fission products. Pile-up is reduced by using a fast amplification chain associated to totally depleted thin detectors. Under these conditions a few mg of {sup 239}Pu can be detected in solutions of fission products having an activity of 100 curies/liter. A method is given for discriminating {alpha} and {beta} particles, it is based on the difference in the collection times for the charges liberated by these particles in the detector. (author) [French] On etudie la detection de particules {alpha} issues de sources epaisses par detecteurs semiconducteurs a jonction diffusee ou a barriere de surface pour le controle continu du procede d'extraction du plutonium. A cet effet on decrit un appareil presentateur dans lequel les solutions a analyser circulent au contact du detecteur protege par une membrane mince de mica. On decrit une methode qui permet par le trace precis des spectres de separer deux ou plusieurs emetteurs {alpha} presents dans une meme solution. Cette methode a ete appliquee a la mesure du {sup 239}Pu en presence de {sup 241}Am avec une precision de {+-} 5 pour cent. Dans la deuxieme partie on traite de la detection du plutonium dans des solutions de produits de fission emetteurs {beta} and {gamma}. On

Gamma-radiolysis of dimethyl sulfoxide. II. Radiolysis yields and possible mechanisms

International Nuclear Information System (INIS)

Gutierrez, M. C.; Barrera, R.

1978-01-01

As result of quantitative studies on gamma-radiolysis of DMSO at a dose range of 90-850 Mrads, constant G values have been obtained for the following radiolysis compounds: G(-DMSO) - 6.7 ±0.2; G(dimethyl sulphide) - 3.4 ±0.3; G(methane) - 0,75 ± 0.04; G(dimethyl disulphide) -0.33 ±0,03; G(tri methylsulphonium methanesulphonate) - 0.26 ± 0,01; G(methyl methanethiosulphonate) - 0,25 ±0.02; G(dimethyl sulphona)-0.21±0.02; G(H 2 )-0.18±0.02; and G(propane)--0.0092±0.0007. Initial G values have been obtained for other identified compounds: Gi(ethane)-0,46; Gi(CO)-0.052; and Gi(CO 2 )-0.030. Possible mechanisms on the radiolysis process are proposed. (Author) 17 refs

Plutonium Plant, Trombay

International Nuclear Information System (INIS)

Yadav, J.S.; Agarwal, K.

2017-01-01

The journey of Indian nuclear fuel reprocessing started with the commissioning of Plutonium Plant (PP) at Trombay on 22"n"d January, 1965 with an aim to reprocess the spent fuel from research reactor CIRUS. The basic process chosen for the plant was Plutonium Uranium Reduction EXtraction (PUREX) process. In seventies, the plant was subjected to major design modifications and replacement of hardware, which later met the additional demand from research reactor DHRUVA. The augmented plutonium plant has been operating since 1983. Experience gained from this plant was very much helpful to design future reprocessing plant in the country

Plutonium and americium recovery from spent molten-salt-extraction salts with aluminum-magnesium alloys

International Nuclear Information System (INIS)

Cusick, M.J.; Sherwood, W.G.; Fitzpatrick, R.F.

1984-01-01

Development work was performed to determine the feasibility of removing plutonium and americium from spent molten-salt-extraction (MSE) salts using Al-Mg alloys. If the product buttons from this process are compatible with subsequent aqueous processing, the complex chloride-to-nitrate aqueous conversion step which is presently required for these salts may be eliminated. The optimum alloy composition used to treat spent 8 wt % MSE salts in the past yielded poor phase-disengagement characteristics when applied to 30 mol % salts. After a limited investigation of other alloy compositions in the Al-Mg-Pu-Am system, it was determined that the Al-Pu-Am system could yield a compatible alloy. In this system, experiments were performed to investigate the effects of plutonium loading in the alloy, excess magnesium, age of the spent salt on actinide recovery, phase disengagement, and button homogeneity. Experimental results indicate that 95 percent plutonium recoveries can be attained for fresh salts. Further development is required for backlog salts generated prior to 1981. A homogeneous product alloy, as required for aqueous processing, could not be produced

Formation and properties of radiation-induced defects and radiolysis products in lithium orthosilicate

Energy Technology Data Exchange (ETDEWEB)

Tiliks, J.E.; Kizane, G.K.; Supe, A.A.; Abramenkovs, A.A.; Tiliks, J.J. (Latvian Univ., Riga (Latvia)); Vasiljev, V.G. (Acad. A.A. Bochvar Inst. of Inorganic Materials, Moscow (USSR))

1991-12-01

Formation and properties of radiation-induced defects and radiolysis products in polycrystalline powders and ceramic pellets of Li{sub 4}SiO{sub 4} were studied under the effect of various types of ionizing irradiation ({gamma} quants, accelerated electrons, reactor irradiation), humidity, temperature, impurities in the samples, etc. The content of radiation defects and radiolysis products poorly depends on irradiation type, dose rate, admixture elements. The concentration of defects highly depends on the temperature of irradiation, humidity, granural size. Empirical dependence of radiolysis degree {alpha} on the dose was found: {alpha}=5x10{sup -2}xD{sup 0.5} for {gamma} and electron irradiation (T{sub rad}=300-350 K) and {alpha}=5x10{sup -3}xD{sup 0.5} for reactor radiation (T{sub rad}=700-800 K); {alpha} - matrix dissociation degree (in %); D - dose (in MGy). Colloidal lithium and silicon, lithium and silicon oxides, and O{sub 2} are the final products of radiolysis. Radiation-induced defects change tritium thermo-extraction parameters, deteriorate mechanical, thermo-physical and electric properties of ceramics. (orig.).

Some studies on the extraction of plutonium from phosphate containing nitric acid solutions using DBDECMP as extractant (Preprint No. CT-24)

International Nuclear Information System (INIS)

Sagar, V.B.; Pawar, S.M.; Oak, M.S.; Sivaramakrishnan, C.K.

1988-02-01

Extraction studies have been carried out to explore the feasibility of separation of Pu(IV) from phosphate containing analytical wastes generated in the laboratory. Distribution data on the extraction of Pu(IV) from dibutyl-N,N diethylcarbamoylmethylenephosphonate (DBDECMP) in xylene from an aqu eous nitric acid and its mixture with sulphuric as well as with sulphuric and phosphoric acids were obtained. Based on the data obtained the conditions for the recovery of plutonium from such waste solutions are suggested. (author)

The effect of plutonium dioxide water surface coverage on the generation of hydrogen and oxygen

Energy Technology Data Exchange (ETDEWEB)

Veirs, Douglas K. [Los Alamos National Laboratory; Berg, John M. [Los Alamos National Laboratory; Crowder, Mark L. [Savannah River National Laboratory

2012-06-20

The conditions for the production of oxygen during radiolysis of water adsorbed onto plutonium dioxide powder are discussed. Studies in the literature investigating the radiolysis of water show that both oxygen and hydrogen can be generated from water adsorbed on high-purity plutonium dioxide powder. These studies indicate that there is a threshold in the amount of water below which oxygen is not generated. The threshold is associated with the number of monolayers of adsorbed water and is shown to occur at approximately two monolayers of molecularly adsorbed water. Material in equilibrium with 50% relative humidity (RH) will be at the threshold for oxygen generation. Using two monolayers of molecularly adsorbed water as the threshold for oxygen production, the total pressure under various conditions is calculated assuming stoichiometric production of hydrogen and oxygen. The specific surface area of the oxide has a strong effect on the final partial pressure. The specific surface areas resulting in the highest pressures within a 3013 container are evaluated. The potential for oxygen generation is mitigated by reduced relative humidity, and hence moisture adsorption, at the oxide surface which occurs if the oxide is warmer than the ambient air. The potential for oxygen generation approaches zero as the temperature difference between the ambient air and the material approaches 6 C.

SEPARATION OF URANIUM, PLUTONIUM, AND FISSION PRODUCTS

Science.gov (United States)

Spence, R.; Lister, M.W.

1958-12-16

Uranium and plutonium can be separated from neutron-lrradiated uranium by a process consisting of dissolvlng the lrradiated material in nitric acid, saturating the solution with a nitrate salt such as ammonium nitrate, rendering the solution substantially neutral with a base such as ammonia, adding a reducing agent such as hydroxylamine to change plutonium to the trivalent state, treating the solution with a substantially water immiscible organic solvent such as dibutoxy diethylether to selectively extract the uranium, maklng the residual aqueous solutlon acid with nitric acid, adding an oxidizing agent such as ammonlum bromate to oxidize the plutonium to the hexavalent state, and selectlvely extracting the plutonium by means of an immlscible solvent, such as dibutoxy dlethyletber.

Production of Plutonium Metal from Aqueous Solutions

Energy Technology Data Exchange (ETDEWEB)

Orth, D.A.

2003-01-16

The primary separation of plutonium from irradiated uranium by the Purex solvent extraction process at the Savannah River Plant produces a dilute plutonium solution containing residual fission products and uranium. A cation exchange process is used for concentration and further decontamination of the plutonium, as the first step in the final preparation of metal. This paper discusses the production of plutonium metal from the aqueous solutions.

Reclamation of plutonium from pyrochemical processing residues

International Nuclear Information System (INIS)

Gray, L.W.; Gray, J.H.; Holcomb, H.P.; Chostner, D.F.

1987-04-01

Savannah River Laboratory (SRL), Savannah River Plant (SRP), and Rocky Flats Plant (RFP) have jointly developed a process to recover plutonium from molten salt extraction residues. These NaCl, KCL, and MgCl 2 residues, which are generated in the pyrochemical extraction of 241 Am from aged plutonium metal, contain up to 25 wt % dissolved plutonium and up to 2 wt % americium. The overall objective was to develop a process to convert these residues to a pure plutonium metal product and discardable waste. To meet this objective a combination of pyrochemical and aqueous unit operations was used. The first step was to scrub the salt residue with a molten metal (aluminum and magnesium) to form a heterogeneous ''scrub alloy'' containing nominally 25 wt % plutonium. This unit operation, performed at RFP, effectively separated the actinides from the bulk of the chloride salts. After packaging in aluminum cans, the ''scrub alloy'' was then dissolved in a nitric acid - hydrofluoric acid - mercuric nitrate solution at SRP. Residual chloride was separated from the dissolver solution by precipitation with Hg 2 (NO 3 ) 2 followed by centrifuging. Plutonium was then separated from the aluminum, americium and magnesium using the Purex solvent extraction system. The 241 Am was diverted to the waste tank farm, but could be recovered if desired

Rapid determination of environmental plutonium in large water samples by means of manganese dioxide Co-precipitation and extraction chromatographic separation

International Nuclear Information System (INIS)

Sidhu, R.S.; Hoff, P.

1999-01-01

Plutonium activity determinations in environmental water samples are routinely performed in many laboratories. Due to the low plutonium concentrations and the complexity of the plutonium aqueous chemistry, these analysis involve cumbersome preconcentration and separation procedures and long measurement times. We describe a procedure where MnO 2 (s) is used as scavenger to preconcentrate Pu prior to separation by the transuranium specific extraction chromatographic resin TRU-Resin. The ability of MnO 4 - /MnO 2 (s) to destroy organic matter and oxidise plutonium is combined with the specific behaviour of the TRU-resin for transuranium elements. The method facilitates a rapid preconcentration and separation of plutonium. With the use of this procedure, the laboratory work on one sample can be performed in one day with minimum attention. The overall yields from a 200 litre fresh- or seawater sample to a measurable Pu source are between 70-85%. (orig.)

Plutonium recovery from carbonate wash solutions

International Nuclear Information System (INIS)

Gray, J.H.; Reif, D.J.; Chostner, D.F.; Holcomb, H.P.

1991-01-01

540Periodically higher than expected levels of plutonium are found in carbonate solutions used to wash second plutonium cycle solvent. The recent accumulation of plutonium in carbonate wash solutions has led to studies to determine the cause of that plutonium accumulation, to evaluate the quality of all canyon solvents, and to develop additional criteria needed to establish when solvent quality is acceptable. Solvent from three canyon solvent extraction cycles was used to evaluate technology required to measure tributyl phosphate (TBP) degradation products and was used to evaluate solvent quality criteria during the development of plutonium recovery processes. 1 fig

Solutions to criticality problems in a plutonium extraction plant; Solutions apportees aux problemes de criticite d'une usine d'extraction du plutonium

Energy Technology Data Exchange (ETDEWEB)

Jouannaud, C; Rodier, J; Fruchard, Y; Peyresblanques, H; Papault, C; Tabardel-Brian, R [Commissariat a l' Energie Atomique, Chusclan (France). Centre de Production de Plutonium de Marcoule, service d' extraction du plutonium, service de protection contre les radiations et d' assainissement radioactif

1968-08-01

There are two aspects to nuclear criticality safety: prevention of criticality and protection against the consequences of a possible accident: this report considers these two aspects in the case of the Marcoule Plutonium Extraction Plant. After briefly recalling the various techniques used for avoiding criticality (mass, geometry, concentration, poisoning), the authors describe their application in the plant and show in particular that, a rational use of a favorable geometry is a factor both for security and from an economic point of view. The authors then describe the inside organisation which makes it possible to obtain the necessary intrinsic safety standard right from the advance project stage, and to control the workshop safety during the operation of the plant. The second part of the report deals with the system of protection against the consequences of a possible accident: definition of a typical accident, fixing of the boundaries of a critical zone, safety alarm device, individual and collective dosimetry, evacuation plan and safety instructions. (authors) [French] La securite vis-a-vis des risques de criticite revet deux aspects: la prevention de la criticite et la protection contre les consequences d'un accident eventuel: le present rapport developpe ces deux aspects dans le cas de l'Usine d'Extraction du Plutonium de Marcoule. Apres avoir rappele les differentes techniques de prevention de la criticite (masse, geometrie, concentration, empoisonnement), les auteurs decrivent leur application a l'Usine et montrent notamment que l'utilisation rationnelle de la geometrie favorable est un double facteur de securite et d'economie. Les auteurs decrivent ensuite l'organisation interieure qui permet de realiser la securite intrinseque des le stade d'un avant projet et de controler la securite des ateliers au cours de la vie de l'Usine. La deuxieme partie du rapport est consacree au systeme de protection contre les consequences d'un accident eventuel: definition d

Idaho Chemical Processing Plant and Plutonium-Uranium Extraction Plant phaseout/deactivation study

International Nuclear Information System (INIS)

Patterson, M.W.; Thompson, R.J.

1994-01-01

The decision to cease all US Department of Energy (DOE) reprocessing of nuclear fuels was made on April 28, 1992. This study provides insight into and a comparison of the management, technical, compliance, and safety strategies for deactivating the Idaho Chemical Processing Plant (ICPP) at Westinghouse Idaho Nuclear Company (WINCO) and the Westinghouse Hanford Company (WHC) Plutonium-Uranium Extraction (PUREX) Plant. The purpose of this study is to ensure that lessons-learned and future plans are coordinated between the two facilities

Gas phase pulse radiolysis

International Nuclear Information System (INIS)

Jonah, C.D.; Andong Liu; Mulac, W.A.

1987-01-01

Gas phase pulse radiolysis, a technique which can be used to study many different phenomena in chemistry and physics, is discussed. As a source of small radicals, pulse radiolysis is important to the field of chemistry, particularly to combustion and atmospheric kinetics. The reactions of 1,3-butadiene, allene, ethylene and acetylene with OH are presented. 52 refs., 1 fig., 1 tab

Liquid-liquid extraction of plutonium(IV) in monoamide - ammonium ionic liquid mixture

International Nuclear Information System (INIS)

Rout, Alok; Venkatesan, K.A.; Antony, M.P.

2016-01-01

Room temperature ionic liquid (RTIL) can be regarded as a sustainable alternative to the conventional molecular diluent, n-dodecane (n-DD), in solvent extraction process. Replacement of volatile organic solvents by RTILs in solvent extraction could lead to inherently safer processes. As far as the cation is concerned, most of the studies reported in literature are focused on imidazolium-based ionic liquids. In contrast to imiadazolium ionic liquids, quarternary ammonium ionic liquids like trioctylmethylammonium chloride (Aliquat 336), trioctylmethylammonium nitrate etc., do not exhibit any cation exchange with the metal ions from aqueous phase during extraction. However, there is no report available in literature that emphasizes the application of trioctylmethylammonium bis(trifluoromethane-sulfonyl)imide ((N_1_8_8_8)(NTf_2)) ionic liquid, for the extraction of Pu(IV). In this paper, we report the advantages of using the ionic liquid, trioctylmethylammonium bis(trifluoromethanesulfonyl)imide ((N_1_8_8_8)(NTf_2)), as diluent, for the extraction of plutonium(IV) in DHOA/(N_1_8_8_8)(NTf_2)

Radiolysis of other organic compounds

International Nuclear Information System (INIS)

Pikaev, A.K.

1986-01-01

Peculiarities of radiolysis of organic halogen, phosphorus, sulfur and nitrogen (including amines, amides, nitriles et al.) compounds in liquid phase are discussed. Intermediate and stable finish products of radiolysis of the given compounds, properties and radiochemical yields of these products are considered

Investigation of behaviour of phosphoric acid and plutonium(4) during extraction by trioctylamine

International Nuclear Information System (INIS)

Baranov, Yu.I.; Malysheva, L.P.; Krivokhatskij, A.S.; Savoskina, G.P.; Smirnova, E.A.

1980-01-01

Chemical studies of the H 3 PO 4 -TOA-diluent system are carried out in order to investigate the behaviour of plutonium(4) in this system. Isotherms of H 3 PO 4 extraction for different TOA concentrations in benzene are presented. The effect of diluents on the extraction of H 3 PO 4 by trioctylamine is studied. IR and PMR spectra of H 3 PO 4 -TOA-CCl 4 solutions are studied. H 3 PO 4 is believed to form with TOA the following compounds: (TOAH) 3 PO 4 , (TOAH) 2 HPO 4 and [(TOAH) 2 HPO 4 ] 3 xH 3 PO 4

Removal of actinides from nuclear fuel reprocessing waste solutions with bidentate organophosphorus extractants

International Nuclear Information System (INIS)

Schulz, W.W.; McIsaac, L.D.

1975-08-01

The neutral bidentate organophosphorus reagents DBDECMP (dibutyl-N,N-diethylcarbamylmethylenephosphonate) and its dihexyl analogue DHDECMP are candidate extractants for removal of actinides from certain acidic waste streams produced at the U. S. ERDA Hanford and Idaho Falls sites. Various chemical and physical properties including availability, cost, purification, alpha radiolysis, and aqueous phase solubility of DBDECMP and DHDECMP are reviewed. A conceptual flowsheet employing a 15 percent DBDECMP (or DHDECMP)--CCl 4 extractant for removal (and recovery) of Am and Pu from Hanford's Plutonium Reclamation Facility acid waste stream (CAW solution) was successfully demonstrated in laboratory-scale mixer-settler tests; this extraction scheme can be used to produce an actinide-free waste. A 30 percent DBDECMP-xylene flowsheet is being tested at the Idaho Falls site for removal of U, Np, Pu, and Am from Idaho Chemical Processing Plant first-cycle high-level raffinate to produce an actinide-free (less than 10 nCi alpha activity/gram) waste. (auth)

Method of stripping plutonium from tributyl phosphate solution which contains dibutyl phosphate-plutonium stable complexes

International Nuclear Information System (INIS)

Ochsenfeld, W.; Schmieder, H.

1976-01-01

Fast breeder fuel elements which have been highly burnt-up are reprocessed by extracting uranium and plutonium into an organic solution containing tributyl phosphate. The tributyl phosphate degenerates at least partially into dibutyl phosphate and monobutyl phosphate, which form stable complexes with tetravalent plutonium in the organic solution. This tetravalent plutonium is released from its complexed state and stripped into aqueous phase by contacting the organic solution with an aqueous phase containing tetravalent uranium. 6 claims, 1 drawing figure

Advances in the sample preparation and the detector for a combined solvent extraction-liquid scintillation method of low-level plutonium measurement

International Nuclear Information System (INIS)

Perdue, P.T.; Christian, D.J.; Thorngate, J.H.; McDowell, W.J.; Case, G.N.

1976-07-01

A combined solvent extraction-liquid scintillation technique, developed at Oak Ridge National Laboratory (ORNL), has many possible applications to the determination of low levels of plutonium and other alpha-emitting nuclides. Using these procedures, plutonium can be extracted from biological or environmental samples and introduced directly into a liquid scintillator. Quenching of the scintillator is thus minimized so that spectroscopic techniques may be employed. Existing chemical procedures and counting equipment were reviewed and improved. Purification of the di(2-ethylhexyl)phosphoric acid (used as the actinide extractant) was found necessary. Destruction of organic material in the sample and control of the valence state of plutonium were found to be major sources of irreproducibility. Methods were developed to allow samples separated with commonly used ion exchange techniques to be extracted into the scintillator. Comparisons were made of a wide variety of the components and parameters of the detector system to find the best combination of pulse-height resolution and pulse-shape discrimination. When a single phototube was used, optimum performance was obtained using a hemispherical reflector-sample holder viewed sideways by an RCA 8575 photomultiplier tube used in conjunction with a special integrating preamplifier and a good quality linear amplifier that used delay lines to shape the pulses

Extraction of plutonium from lean residues by room-temperature fluoride volatility

International Nuclear Information System (INIS)

Campbell, G.M.; Foropoulos, J.; Kennedy, R.C.; Dye, B.A.; Behrens, R.G.

1990-01-01

The use of dioxygen difluoride and krypton difluoride for the recovery of plutonium from lean residues by conversion to gaseous plutonium hexa-fluoride is being investigated. The synthesis of dioxygen difluoride in practical quantity has been demonstrated. Fluorination of plutonium compounds under ideal conditions supports the contention that a viable process can be developed. Application of the method to lean plutonium residues is in the early stage of development

The first metallurgical tests on plutonium

International Nuclear Information System (INIS)

Grison, E.; Abramson, R.; Anselin, F.; Monti, H.

1958-01-01

Metallic plutonium was first prepared in France in January 1956, as soon as we had access to quantities of the order of several grams of plutonium, which had been extracted from the rods of the pile EL2 at Saclay. Since up to the present this reactor, of thermal power 2 000 kW, has been our only source of plutonium, we have so far only worked on experimental quantities sufficient for the basic tests but not for tests on a scale of possible applications. It is this work, carried out during this phase of preliminary research, which is described below. With the starting up of the plutonium extraction plant at Marcoule, where the reactor G1 has been operating at power for more than a year, we shall go on next to a another order of magnitude which will allow the manufacture and experimentation of prototype fuel elements. (author) [fr

Rapid and simultaneous determination of neptunium and plutonium isotopes in environmental samples by extraction chromatography using sequential injection analysis and ICP-MS

DEFF Research Database (Denmark)

Qiao, Jixin; Hou, Xiaolin; Roos, Per

2010-01-01

plutonium and neptunium in three reference materials were in agreement with the recommended or literature values at the 0.05 significance level. The developed method is suitable for the analysis of up to 10 g of soil and 20 g of seaweed samples. The extraction chromatographic separation within the SI system......This paper reports an automated analytical method for rapid and simultaneous determination of plutonium isotopes (239Pu and 240Pu) and neptunium (237Np) in environmental samples. An extraction chromatographic column packed with TrisKem TEVA® resin was incorporated in a sequential injection (SI...... for a single sample takes less than 1.5 h. As compared to batchwise procedures, the developed method significantly improves the analysis efficiency, reduces the labor intensity and expedites the simultaneous determination of plutonium and neptunium as demanded in emergency actions....

EXPECTED IMPACT OF HANFORD PROCESSING ORGANICS OF PLUTONIUM DURING TANK WASTE SLUDGE RETRIEVAL

International Nuclear Information System (INIS)

TROYER, G.L.; WINTERS, W.I.

2004-01-01

This document evaluates the potential for extracting plutonium from Hanford waste tanks into residual organic solvents and how this process may have an impact on criticality specifications during the retrieval of wastes. The two controlling factors for concentrating plutonium are the solubility of the plutonium in the wastes and the extraction efficiency of the potential organic extractants that may be found in these wastes. Residual Hanford tank sludges contain plutonium in solid forms that are expected to be primarily insoluble Pu(IV) hydroxides. Evaluation of thermodynamic Pourbaix diagrams, documentation on solubility studies of various components in waste tank matrices, and actual analysis of plutonium in tank supernates all indicate that the solubility of Pu in the alkaline waste is on the order of 10 -6 M. Based on an upper limit plutonium solubility of 10 -5 M in high pH and a conservative distribution coefficient for organic extractants of a 0 for plutonium in 30% TBP at 0.07 M HNO 3 ), the estimated concentration for plutonium in the organic phase would be -7 M. This is well below the process control criteria. A significant increase in plutonium solubility or the E a o would have to occur to raise this concentration to the 0.01 M concern level for organics. Measured tank chemical component values, expected operating conditions, and the characteristics of the expected chemistry and extraction mechanisms indicate that concentration of plutonium from Hanford tank residual sludges to associated process organic extractants is significantly below levels of concern

Role of ligand basicity and stereochemistry in the extraction of plutonium(IV) isoxazolonates

International Nuclear Information System (INIS)

Mohapatra, P.K.; Manchanda, V.K.

2003-01-01

The extraction behaviour of plutonium (IV) was investigated from nitric acid and perchloric acid using 3-phenyl-4-benzoyl-5-isoxazolone (HPBI) as well as a mixture of HPBI and tri-n-octyl phosphine oxide (TOPO) in xylene. Studies on the binary extraction system Pu(IV)-HPBI indicated extraction of species of the type Pu(PBI) 4 . In the presence of TOPO, while species of the type Pu(PBI) 3 (ClO 4 ).(TOPO) and Pu(PBI) 4 .TOPO were co-extracted from perchloric acid medium, a mixture of Pu(PBI) 2 (NO 3 ) 2 .2TOPO, Pu(PBI) 3 (NO 3 ).(TOPO) and Pu(PBI) 4 .TOPO were co-extracted from nitric acid medium. In addition to the electronic factors, steric factors were found to play a significant role during the formation of binary/ternary/quaternary complexes. The steric hindrance due to the unusual conformation of the isoxazolone led to lowering of the equilibrium constants for both the binary and ternary extraction systems. Possible steric factor influences are explained with the help of molecular modelling. (orig.)

Detection of {alpha} particles using semiconductors. Application to the control of plutonium extraction; Detection des particules {alpha} par semiconducteurs application au controle de l'extraction du plutonium

Energy Technology Data Exchange (ETDEWEB)

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

1968-03-01

A study is made of a particles produced by thick sources, using either diffused junction or surface barrier semiconductor detectors for controlling continuously the plutonium extraction process. For this, a presenting apparatus is described in which the solutions to be analyzed flow in contact with the detector protected by a thin mica membrane. A method is described which gives a precise recording of the spectra and which thus allows the separation of two or more {alpha} emitters present in the same solution. This method has been applied to the measurement of {sup 239}Pu in the the presence of {sup 241}Am with an accuracy of {+-}5 per cent. In the second part of the report is considered the detection of plutonium in solutions of {beta} - {gamma} emitting fission products. Pile-up is reduced by using a fast amplification chain associated to totally depleted thin detectors. Under these conditions a few mg of {sup 239}Pu can be detected in solutions of fission products having an activity of 100 curies/liter. A method is given for discriminating {alpha} and {beta} particles, it is based on the difference in the collection times for the charges liberated by these particles in the detector. (author) [French] On etudie la detection de particules {alpha} issues de sources epaisses par detecteurs semiconducteurs a jonction diffusee ou a barriere de surface pour le controle continu du procede d'extraction du plutonium. A cet effet on decrit un appareil presentateur dans lequel les solutions a analyser circulent au contact du detecteur protege par une membrane mince de mica. On decrit une methode qui permet par le trace precis des spectres de separer deux ou plusieurs emetteurs {alpha} presents dans une meme solution. Cette methode a ete appliquee a la mesure du {sup 239}Pu en presence de {sup 241}Am avec une precision de {+-} 5 pour cent. Dans la deuxieme partie on traite de la detection du plutonium dans des solutions de produits de fission emetteurs {beta} and {gamma

Determination of iron in plutonium by extraction of the Fe (2): Bathophenanthroline complex

International Nuclear Information System (INIS)

Pichotin, B.; Chasseur, Ph.

1966-06-01

The present report describes the method to determine micro quantities of iron in plutonium, by extraction with hexyl alcohol of the complex that give iron (II) with bathophenanthroline (4,7 diphenyl - 1.10 phenanthroline). The reagent has been applied to the determination of amounts of iron ranging from 1 to 10 μg in 20 ml of solvent The determination is made by spectrophotometry at 530 mμ. Others cations present do not interfere. (authors) [fr

The application of radiolysis and analysis of influencing factors

International Nuclear Information System (INIS)

Xie Fang; Ha Yiming; Wang Feng

2008-01-01

As a branch of radiation technology, radiolysis technology has been developing in recent years. The update research and application of radiolysis is briefly reviewed. The radiolysis in reducing veterinary drug residues in food, processing plant sources products and environmental management are summaried. The influencing factors or the mechanism and radiolysis products are reviewed. (authors)

Recovery of plutonium and americium from chloride salt wastes by solvent extraction

International Nuclear Information System (INIS)

Reichley-Yinger, L.; Vandegrift, G.F.

1987-01-01

Plutonium and americium can be recovered from aqueous waste solutions containing a mixture of HCl and chloride salt wastes by the coupling of two solvent extraction systems: tributyl phosphate (TBP) in tetrachloroethylene (TCE) and octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) in TCE. In the flowsheet developed, the salt wastes are dissolved in HCl, the Pu(III) is oxidized to the IV state with NaClO 2 and recovered in the TBP-TCE cycle, and the Am is then removed from the resultant raffinate by the CMPO-TCE cycle. The consequences of the feed solution composition and extraction behavior of these species on the process flowsheet design, the Pu-product purity, and the decontamination of the aqueous raffinate from transuranic elements are discussed. 16 refs., 6 figs

Oxidizing dissolution of spent MOX47 fuel subjected to water radiolysis: Solution chemistry and surface characterization by Raman spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Jegou, C., E-mail: christophe.jegou@cea.f [Commissariat a l' Energie Atomique (CEA), Marcoule Reasearch Center, B.P. 17171, F-30207 Bagnols-sur-Ceze Cedex (France); Caraballo, R.; De Bonfils, J.; Broudic, V.; Peuget, S. [Commissariat a l' Energie Atomique (CEA), Marcoule Reasearch Center, B.P. 17171, F-30207 Bagnols-sur-Ceze Cedex (France); Vercouter, T. [Commissariat a l' Energie Atomique (CEA), Saclay Reasearch Center, B.P. 11, F-91191 Gif-sur-Yvette Cedex (France); Roudil, D. [Commissariat a l' Energie Atomique (CEA), Marcoule Reasearch Center, B.P. 17171, F-30207 Bagnols-sur-Ceze Cedex (France)

2010-04-01

The mechanisms of oxidizing dissolution of spent MOX fuel (MIMAS TU2 (registered) ) subjected to water radiolysis were investigated experimentally by leaching spent MOX47 fuel samples in pure water at 25 deg. C under different oxidizing conditions (with and without external gamma irradiation); the leached surfaces were characterized by Raman spectroscopy. The highly oxidizing conditions resulting from external gamma irradiation significantly increased the concentration of plutonium (Pu(V)) and uranium (U(VI)) compared with a benchmark experiment (without external irradiation). The oxidation behavior of the plutonium-enriched aggregates differed significantly from that of the UO{sub 2} matrix after several months of leaching in water under gamma irradiation. The plutonium in the aggregates appears to limit fuel oxidation. The only secondary phases formed and identified to date by Raman spectroscopy are uranium peroxides that generally precipitate on the surface of the UO{sub 2} grains. Concerning the behavior of plutonium, solution analysis results appear to be compatible with a conventional explanation based on an equilibrium with a Pu(OH){sub 4(am)} phase. The fission product release - considered as a general indicator of matrix alteration - from MOX47 fuel also increases under external gamma irradiation and a change in the leaching mode is observed. Diffusive leaching was clearly identified, coinciding with the rapid onset of steady-state actinide concentrations in the bulk solution.

The determination of plutonium isotopes in environmental samples

International Nuclear Information System (INIS)

Siripirom, Lopchai.

1983-01-01

The concentration of plutonium in environmental samples such as soil, water, and surface air in the middle part of Thailand were studied. The surface air were collected only at the fifth floor of the Office of Atomic Energy for Peace (OAEP). Plutonium-242 was used as a tracer. Soil and air samples were dissolved by pyrosulphate fusion, and plutonium was co-precipitated with barium sulfate. Then dissolved the precipitate in perchloric acid. Plutonium was extracted out by using solvent bis-(2-ethylhexyl) phosphoric acid (HDEHP). Plutonium in water samples were coprecipitated with iron (III) hydroxide and were dissolved in 8 M. nitric acid. Then the plutonium was separated out by using anion exchange resin, Dowex 1x4. After the solvent extraction or the anion exchange, plutonium was coprecipitated with cerous hydroxide. The activities of plutonium were measured by a surface barrier detector for about 24 hours. Lower limit of detection for 1,440 minutes is 0.012 pCi. These studies showed that only plutonium-239, 240 was observed. The range of activities of plutonium-239, 240 in soil were 0.002-0.157 pCi/g (dry), in water were 0.1-81 f Ci/l, and in air were 7-330 a Ci/m 3 . However, the plutonium concentrations in these studies are far below the maximum permissible concentration (MPC) recommended by International Commission on Radiological Protection (ICRP) for general population which is equal to 3x10 8 f Ci/l of water and 5x10 6 a Ci/m 3 of air

Study of a plutonium substitute for the reducing back-extraction in low flow rate contactors

International Nuclear Information System (INIS)

Morell, M.

1998-01-01

The aim of this work is to define and carry out a non-radioactive redox chemical system, similar to those of the plutonium, in a reducing back-extraction operation. In the first part, we have replaced our study within the context of the spent fuels. The choice of cerium as a plutonium substitute is justified and the used centrifugal drier described. The current process is presented and the set problem explained. The experimental study concerns essentially the research of reducers of the chosen substitute, the stability of ceric solutions, the measurement of distribution coefficients and the study of redox chemical kinetics. In the last part, are given the used simulation tools (development of a mathematical model in a first step and adaptation of the PAREX code in the second step) and the results of their comparison with the experimental data

Technical considerations and policy requirements for plutonium management

International Nuclear Information System (INIS)

Christensen, D.C.; Dinehart, S.M.; Yarbro, S.L.

1995-01-01

The goals for plutonium management have changed dramatically over the past few years. Today, the challenge is focused on isolating plutonium from the environment and preparing it for permanent disposition. In parallel, the requirements for managing plutonium are rapidly changing. For example, there is a significant increase in public awareness on how facilities operate, increased attention to environmental safety and health (ES and H) concerns, greater interest in minimizing waste, more emphasis on protecting material from theft, providing materials for international inspection, and a resurgence of interest in using plutonium as an energy source. Of highest concern, in the immediate future, is protecting plutonium from theft or diversion, while the national policy on disposition is debated. These expanded requirements are causing a broadening of responsibilities within the Department of Energy (DOE) to include at least seven organizations. An unavoidable consequence is the divergence in approach and short-term goals for managing similar materials within each organization. The technology base does exist, properly, safely, and cost effectively to extract plutonium from excess weapons, residues, waste, and contaminated equipment and facilities, and to properly stabilize it. Extracting the plutonium enables it to be easily inventoried, packaged, and managed to minimize the risk of theft and diversion. Discarding excess plutonium does not sufficiently reduce the risk of diversion, and as a result, long-term containment of plutonium from the environment may not be able to be proven to the satisfaction of the public

Technical considerations and policy requirements for plutonium management

International Nuclear Information System (INIS)

Christensen, D.C.; Dinehart, S.M.; Yarbro, S.L.

1996-01-01

The goals for plutonium management have changed dramatically over the past few years. Today, the challenge is focused on isolating plutonium from the environment and preparing it for permanent disposition. In parallel, the requirements for managing plutonium are rapidly changing. For example, there is a significant increase in public awareness on how facilities operate, increased attention to environmental safety and health (ES and H) concerns, greater interest in minimizing waste, more emphasis on protecting material from theft, providing materials for international inspection, and a resurgence of interest in using plutonium as an energy source. Of highest concern, in the immediate future, is protecting plutonium from theft or diversion, while the national policy on disposition is debated. These expanded requirements are causing a broadening of responsibilities within the Department of Energy (DOE) to include at least seven organizations. An unavoidable consequence is the divergence in approach and short-term goals for managing similar materials within each organization. The technology base does exist, properly, safely, and cost effectively to extract plutonium from excess weapons, residues, waste, and contaminated equipment and facilities, and to properly stabilize it. Extracting the plutonium enables it to be easily inventoried, packaged, and managed to minimize the risk of theft and diversion. Discarding excess plutonium does not sufficient reduce the risk of diversion, and as a result, long-term containment of plutonium from the environment may not be able to be proven to the satisfaction of the public

Characterization of past and present solid waste streams from the Plutonium-Uranium Extraction Plant

International Nuclear Information System (INIS)

Pottmeyer, J.A.; Weyns, M.I.; Lorenzo, D.S.; Vejvoda, E.J.; Duncan, D.R.

1993-04-01

During the next two decades the transuranic wastes, now stored in the burial trenches and storage facilities at the Hanford Site, are to be retrieved, processed at the Waste Receiving and Processing Facility, and shipped to the Waste Isolation Pilot Plant near Carlsbad, New Mexico for final disposal. Over 7% of the transuranic waste to be retrieved for shipment to the Waste Isolation Pilot Plant has been generated at the Plutonium-Uranium Extraction (PUREX) Plant. The purpose of this report is to characterize the radioactive solid wastes generated by PUREX using process knowledge, existing records, and oral history interviews. The PUREX Plant is currently operated by the Westinghouse Hanford Company for the US Department of Energy and is now in standby status while being prepared for permanent shutdown. The PUREX Plant is a collection of facilities that has been used primarily to separate plutonium for nuclear weapons from spent fuel that had been irradiated in the Hanford Site's defense reactors. Originally designed to reprocess aluminum-clad uranium fuel, the plant was modified to reprocess zirconium alloy clad fuel elements from the Hanford Site's N Reactor. PUREX has provided plutonium for research reactor development, safety programs, and defense. In addition, the PUREX was used to recover slightly enriched uranium for recycling into fuel for use in reactors that generate electricity and plutonium. Section 2.0 provides further details of the PUREX's physical plant and its operations. The PUREX Plant functions that generate solid waste are as follows: processing operations, laboratory analyses and supporting activities. The types and estimated quantities of waste resulting from these activities are discussed in detail

Determination of low level of plutonium and uranium isotopes in safeguard swipe sample

Energy Technology Data Exchange (ETDEWEB)

Lee, Myung Ho; Park, Jong Ho; Oh, Seong Yong; Lee, Chang Heon; Ahn, Hong Ju; Song, Kyu Seok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2011-10-15

For the determination of radionuclides, the separation techniques based on the principles of anion exchange, liquid-liquid extraction or column extraction chromatography are frequently used in nuclear analytical applications. Recently, a novel extraction chromatographic resin has been developed by Horwitz and co-workers, which are capable of selective extraction of the actinides. General separation of plutonium and uranium with extraction chromatographic techniques are focused on the environmental or radioactive waste samples. Also, the chemical yields for Pu and U isotopes with extraction chromatographic method sometimes are variable. For effective extraction of Pu isotopes in the very level of plutonium sample with UTEVA resin, the valence adjustment of Pu isotopes in the sample solution requires due to unstability in the oxidation state of Pu isotopes during separation step. Therefore, it is necessary to develop a simple and robust radiochemical separation method for nano- or pico gram amounts of uranium and plutonium in safeguard swipe samples. Chemical yields of plutonium and uranium with extraction chromatographic method of Pu and U upgrades in this study were compared with several separation methods for Pu and U generally used in the radiochemistry field. Also, the redox reactions of hydrogen peroxide with plutonium in the nitric acid media were investigated by UV-Vis-NIR absorption spectroscopy. Based on general extraction chromatography method with UTEVA resin, the separation method of nano- and picogram amounts of uranium and plutonium in safeguard swipe samples was developed in this study

Chemical characterization of local and stratospheric plutonium in Ohio soils

International Nuclear Information System (INIS)

Muller, R.N.

1978-01-01

The chemical nature of plutonium derived from stratospheric fallout and industrial sources was studied in three agricultural soils. The majority of the soil plutonium was associated with a reductant-soluble, hydrous oxide phase that, under most conditions of terrestrial ecosystems, remains essentially immobile. The proportion of plutonium associated with organic matter (0.1N NaOH-extractable) varied among soils, and increased with decreasing particle size in the same soil. In a soil containing 238 Pu from a local fabrication facility and 239 , 240 Pu from stratospheric fallout, isotopic ratios between the NaOH-extractable and residual phases were essentially constant, indicating that, in these soils, plutonium from both sources behaves similarly. The distribution of soil plutonium with particle size appears to be most directly related to the mass of the soil particle

Plutonium in domestic animals and man

International Nuclear Information System (INIS)

Coughtrey, P.J.; Jackson, D.; Jones, C.H.; Kane, P.; Thorne, M.C.

1984-01-01

This chapter deals with plutonium adsorption, retention and translocation rates in lungs, the gastrointestinal tract, liver and in body tissues of domestic animals and man. Urinary and faecal excretion of plutonium is discussed. Transfer rates to eggs, milk, foetus and newborn are considered. Of all these subjects, data are presented extracted from literature and cast in tables

Some mechanisms which may reduce radiolysis

Energy Technology Data Exchange (ETDEWEB)

Neretnieks, I; Faghihi, M. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Chemical Engineering

1991-08-01

In this report two mechanisms which may considerably decrease the rate of radiolysis are studied. The first main effect is that capillary forces in the very fine pores of the bentonite which surround the canisters do not permit the release of water if there is a gas over pressure inside the canister. As long as there is gas inside the canister the gap will partly be gas filled and the alpha-particles will have less water to radiolyze. Because some hydrogen will be dissolved and will escape by diffusion, a rate of radiolysis will be maintained which balances the rate of diffusion. This in turn will be influenced by the geometry of the diffusion path. The size of the hole in the copper canister seems to be one of the critical items which determine the escape of the hydrogen and thus the rate of radiolysis. The other main effect which will reduce the radiolysis is the accumulation of the corrosion products in the gap. This reduces the water content in the gap. Consequently there will be less water which can be radiolyzed. The presence of corrosion products which have a higher density than water will also consume the energy of the alpha-particles faster. Both effects seem to, independently, have a potential of reducing the rate of radiolysis by a few order of magnitude.

Some mechanisms which may reduce radiolysis

International Nuclear Information System (INIS)

Neretnieks, I; Faghihi, M.

1991-08-01

In this report two mechanisms which may considerably decrease the rate of radiolysis are studied. The first main effect is that capillary forces in the very fine pores of the bentonite which surround the canisters do not permit the release of water if there is a gas over pressure inside the canister. As long as there is gas inside the canister the gap will partly be gas filled and the alpha-particles will have less water to radiolyze. Because some hydrogen will be dissolved and will escape by diffusion, a rate of radiolysis will be maintained which balances the rate of diffusion. This in turn will be influenced by the geometry of the diffusion path. The size of the hole in the copper canister seems to be one of the critical items which determine the escape of the hydrogen and thus the rate of radiolysis. The other main effect which will reduce the radiolysis is the accumulation of the corrosion products in the gap. This reduces the water content in the gap. Consequently there will be less water which can be radiolyzed. The presence of corrosion products which have a higher density than water will also consume the energy of the alpha-particles faster. Both effects seem to, independently, have a potential of reducing the rate of radiolysis by a few order of magnitude

Electrons in water radiolysis

International Nuclear Information System (INIS)

Laverne, J.A.; Pimblott, S.M.

2006-01-01

The hydrated electron is the main reducing species produced in the radiolysis of water. Many studies have examined its reactivity using pulsed radiolysis techniques and competition kinetics. Data bases list hundreds of rate coefficients for reaction of the hydrated electron with substances ranging from inorganic ions like nitrate to biopolymers like DNA. Although the chemistry of the hydrated electron is often examined, its mechanism of formation and variation in yield are considerable less known, especially under extreme conditions such as in high temperature water or with heavy ion radiolysis. This work will examine various aspects of the radiation chemistry of the hydrated electron beginning with the generation of secondary electrons in primary energy loss events during the passage of ionizing radiation to the radiolytic yields of the hydrated electron produced by different types of radiation. Ion radiation is a 'white light source.' Energy losses range from the minimum excitation energy of the medium up to the kinematic maximum determined by the collision parameters. However, certain energy loss events are more probable than others. The dipole oscillator strength distributions of media essentially give the probability of energy loss events in collisions with no momentum transfer. Dipole oscillator distributions have been constructed from experimental data for a wide variety of materials including all the phases of water. Calculations using cross sections based on dipole oscillator distributions show that the most probable energy loss event in water is only about 20 eV with an average value closer to 60 eV. The preponderance of energy loss events of less than 100 eV means that many low energy electrons are formed by the passage of a single ion. Low energy electrons have short mean free paths and they remain in the vicinity of the primary energy loss events. The spatial distribution of these low energy electrons defines the radial track structure of the incident

ECP evaluation by water radiolysis and ECP model calculations

Energy Technology Data Exchange (ETDEWEB)

Hanawa, S.; Nakamura, T.; Uchida, S. [Japan Atomic Energy Agency, Tokai-mura, Ibaraki (Japan); Kus, P.; Vsolak, R.; Kysela, J. [Nuclear Research Inst. Rez plc, Rez (Czech Republic)

2010-07-01

In-pile ECP measurements data was evaluated by water radiolysis calculations. The data was obtained by using an in-pile loop in an experimental reactor, LVR-15, at the Nuclear Research Institute (NRI) in Czech Republic. Three types of ECP sensors, a Pt electrode, an Ag/AgCl sensor and a zirconia membrane sensor containing Ag/Ag{sub 2}O were used at several levels of the irradiation rig at various neutron flux and gamma rates. For water radiolysis calculation, the in-pile loop was modeled to several nodes following their design specifications, operating conditions such as flow rates, dose rate distributions of neutron and gamma-ray and so on. Concentration of chemical species along the water flow was calculated by a radiolysis code, WRAC-J. The radiolysis calculation results were transferred to an ECP model. In the model, anodic and cathodic current densities were calculated with combination of an electrochemistry model and an oxide film growth model. The measured ECP data were compared with the radiolysis/ECP calculation results, and applicability the of radiolysis model was confirmed. In addition, anomalous phenomenon appears in the in-pile loop was also investigated by radiolysis calculations. (author)

A pulse radiolysis study of hyperoside isolated from Hypericum mysorense

International Nuclear Information System (INIS)

Hariharapura, Raghu C.; Mahal, H.S.; Srinivasan, R.; Jagani, Hitesh; Vijayan, P.

2015-01-01

Background: The recent growth in knowledge of free radicals in biology is producing a medical revolution that promises a new age in health and disease management. In the last two decades there has been an explosive interest in the role of oxygen free radicals, more generally known as “reactive oxygen species” and of “reactive nitrogen species” in experimental and clinical medicine. Methods: The flowering top extract of Hypericum mysorense possessing potent anti-oxidant activity was subjected to bio-active guided isolation. Pulse radiolysis technique was used to determine the transient spectrum and rate constant for the one-electron oxidation of hyperoside by · OH, N 3 · , NO 2 · , NO · , CCl 3 OO · radicals in aqueous solution. Results: Three compounds were isolated and characterized as rutin, quercetin-3-O-galactoside (hyperoside) and quercetin from spectral analysis. The hyperoside radical showed pK a1 and pK a2 at 5.4 and 9.2. Both, Cu(II) and iron(II) ions form chelate with hyperoside. The Cu–hyperoside chelate was able to scavenge O 2 ·− , k=7.0(±0.3)×10 6 dm 3 mol −1 s −1 at pH 9. The repair rates for tryptophan and guanosine radicals by hyperoside were also determined. Conclusion: The reduction potential of hyperoside radical was determined by cyclic voltammetric and pulse radiolysis methods. - Highlights: • Hyperoside, rutin and quercetin were isolated from extract of Hypericum mysorense. • Rate constant of hyperoside was determined by Pulse radiolysis technique. • The hyperoside radical showed pK a1 and pK a2 at 5.4 and 9.2. • Cu(II) and iron(II)ions form chelate with hyperoside. • Hyperoside can repair the damage to guanosine, tryptophan radicals

Decontaminaion of metals containing plutonium and americium

International Nuclear Information System (INIS)

Seitz, M.G.; Gerding, T.J.; Steindler, M.J.

1979-06-01

Melt-slagging (melt-refining) techniques were evaluated as a decontamination and consolidation step for metals contaminated with oxides of plutonium and americium. Experiments were performed in which mild steel, stainless steel, and nickel contaminated with oxides of plutonium and americium were melted in the presence of silicate slags of various compositions. The metal products were low in contamination, with the plutonium and americium strongly fractionated to the slags. Partition coefficients (plutonium in slag/plutonium in steel) of 7 x 10 6 were measured with boro-silicate slag and of 3 x 10 6 with calcium, magnesium silicate slag. Decontamination of metals containing as much as 14,000 ppM plutonium appears to be as efficient as for metals with plutonium levels of 400 ppM. Staged extraction, that is, a remelting of processed metal with clean slag, results in further decontamination of the metal. The second extraction is effective with either resistance-furnace melting or electric-arc melting. Slag adhering to the metal ingots and in defects within the ingots is in the important contributors to plutonium retained in processed metals. If these sources of plutonium are controlled, the melt-refining process can be used on a large scale to convert highly contaminated metals to homogeneous and compact forms with very low concentrations of plutonium and americium. A conceptual design of a melt-refining process to decontaminate plutonium- and americium-contaminated metals is described. The process includes single-stage refining of contaminated metals to produce a metal product which would have less than 10 nCi/g of TRU-element contamination. Two plant sizes were considered. The smaller conceptual plant processes 77 kg of metal per 8-h period and may be portable.The larger one processes 140 kg of metal per 8-h period, is stationary, and may be near te maximum size that is practical for a metal decontamination process

Radiolysis characterization of chloramphenicol in powder and in eye ointment

International Nuclear Information System (INIS)

Hong, L.; Altorfer, H.R.

2005-01-01

The effects of γ-radiation sterilization on chloramphenicol, in both pure powder state and petrolatum eye ointment, were investigated with high performance liquid chromatography. The content of chloramphenicol decreases by 1.0% in powder state and by 1.2% in eye ointment at the reference radiation dose of 25 kGy. The profile of chloramphenicol radiolysis products in powder state differs from that in eye ointment. It was found that microenvironment of chloramphenicol molecule is a key factor governing the radiolysis of chloramphenicol in powder state. Solvent residues in chloramphenicol powder could change the radiolysis behavior of chloramphenicol. The solvents, having good solubility for chloramphenicol, promote radiolytic hydrolysis of chloramphenicol, but the converses do not. Inert gas purging or diffusion by exposing in absorbent is efficient method to prevent chloramphenicol powder from radiolysis. The influence of the presence of oxygen was explored. Oxygen plays a role of scavenger and diminishes radiolysis of chloramphenicol. It was found that Nactyl-L-cysteine can protection chloramphenicol in eye ointment from radiolysis. Hydrophobic radiolysis products of chloramphenicol were observed in eye ointment part. Using scavengers and lower irradiation can be strategies to resist radiolysis of chloramphenicol in petrolatum eye ointment. (author)

Solutions to criticality problems in a plutonium extraction plant

International Nuclear Information System (INIS)

Jouannaud, C.; Rodier, J.; Fruchard, Y.; Peyresblanques, H.; Papault, C.; Tabardel-Brian, R.

1968-08-01

There are two aspects to nuclear criticality safety: prevention of criticality and protection against the consequences of a possible accident: this report considers these two aspects in the case of the Marcoule Plutonium Extraction Plant. After briefly recalling the various techniques used for avoiding criticality (mass, geometry, concentration, poisoning), the authors describe their application in the plant and show in particular that, a rational use of a favorable geometry is a factor both for security and from an economic point of view. The authors then describe the inside organisation which makes it possible to obtain the necessary intrinsic safety standard right from the advance project stage, and to control the workshop safety during the operation of the plant. The second part of the report deals with the system of protection against the consequences of a possible accident: definition of a typical accident, fixing of the boundaries of a critical zone, safety alarm device, individual and collective dosimetry, evacuation plan and safety instructions. (authors) [fr

Plutonium fires; Incendies de plutonium

Energy Technology Data Exchange (ETDEWEB)

Mestre, E.

1959-06-23

The author reports an information survey on accidents which occurred when handling plutonium. He first addresses accidents reported in documents. He indicates the circumstances and consequences of these accidents (explosion in glove boxes, fires of plutonium chips, plutonium fire followed by filter destruction, explosion during plutonium chip dissolution followed by chip fire). He describes hazards associated with plutonium fires: atmosphere and surface contamination, criticality. The author gives some advices to avoid plutonium fires. These advices concern electric installations, the use of flammable solvents, general cautions associated with plutonium handling, venting and filtration. He finally describes how to fight plutonium fires, and measures to be taken after the fire (staff contamination control, atmosphere control)

Transplutonium elements production program: extraction chromatographic process for plutonium irradiated targets

International Nuclear Information System (INIS)

Bourges, J.; Madic, C.; Koehly, G.

1980-01-01

The treatment of irradiated plutonium targets by extraction chromatography allowed the purification of the isotopes 243 Am and 244 Cm on the scale of few tens of grams. This process proved to be extremely simple and flexible, and yielded results which are reproducible in time. The chief advantage of the TBP process over the HDEHP process in high and medium activity conditions lies in the rapid absorption/desorption kinetics of the elements to be purified and in the separation of americium from curium, which largely offsets its lower selectivity for lanthanide elements. it is certainly possible to improve the performance of this process by: a) optimization of the characteristics of the stationary phase, b) improvement in the filling technique and in hydraulic operation of the columns, c) on-line analysis of americium (the key element in actinide/lanthanide separation) in the eluate. The application of extraction chromatography with HD(DiBM)P to the purification of 243 Am of the end of treatment makes the process more consistent, eliminates the delicate stages implemented in hot cell, and considerably improves final product quality

Solutions to criticality problems in a plutonium extraction plant; Solutions apportees aux problemes de criticite d'une usine d'extraction du plutonium

Energy Technology Data Exchange (ETDEWEB)

Jouannaud, C.; Rodier, J.; Fruchard, Y.; Peyresblanques, H.; Papault, C.; Tabardel-Brian, R. [Commissariat a l' Energie Atomique, Chusclan (France). Centre de Production de Plutonium de Marcoule, service d' extraction du plutonium, service de protection contre les radiations et d' assainissement radioactif

1968-08-01

There are two aspects to nuclear criticality safety: prevention of criticality and protection against the consequences of a possible accident: this report considers these two aspects in the case of the Marcoule Plutonium Extraction Plant. After briefly recalling the various techniques used for avoiding criticality (mass, geometry, concentration, poisoning), the authors describe their application in the plant and show in particular that, a rational use of a favorable geometry is a factor both for security and from an economic point of view. The authors then describe the inside organisation which makes it possible to obtain the necessary intrinsic safety standard right from the advance project stage, and to control the workshop safety during the operation of the plant. The second part of the report deals with the system of protection against the consequences of a possible accident: definition of a typical accident, fixing of the boundaries of a critical zone, safety alarm device, individual and collective dosimetry, evacuation plan and safety instructions. (authors) [French] La securite vis-a-vis des risques de criticite revet deux aspects: la prevention de la criticite et la protection contre les consequences d'un accident eventuel: le present rapport developpe ces deux aspects dans le cas de l'Usine d'Extraction du Plutonium de Marcoule. Apres avoir rappele les differentes techniques de prevention de la criticite (masse, geometrie, concentration, empoisonnement), les auteurs decrivent leur application a l'Usine et montrent notamment que l'utilisation rationnelle de la geometrie favorable est un double facteur de securite et d'economie. Les auteurs decrivent ensuite l'organisation interieure qui permet de realiser la securite intrinseque des le stade d'un avant projet et de controler la securite des ateliers au cours de la vie de l'Usine. La deuxieme partie du rapport est consacree au systeme de protection contre les

Stop plutonium; Stop plutonium

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-02-01

This press document aims to inform the public on the hazards bound to the plutonium exploitation in France and especially the plutonium transport. The first part is a technical presentation of the plutonium and the MOX (Mixed Oxide Fuel). The second part presents the installation of the plutonium industry in France. The third part is devoted to the plutonium convoys safety. The highlight is done on the problem of the leak of ''secret'' of such transports. (A.L.B.)

Contribution to the study of the process of purification of plutonium by extraction with trilaurylamine

International Nuclear Information System (INIS)

Saey, Jean-Claude

1966-01-01

This work addresses the process of plutonium purification which uses trilaurylamine nitrate. In order to use this nitrate in its solid state and at ordinary temperature, a secondary solvent must be added which must have some properties: low volume mass and viscosity, high boiling and ignition temperatures, rather low miscibility with water, high stability in front of joint actions of nitric acid and radiations, and no reaction with the alkylammonium nitrate and the complex. Thus, the author addresses phenomena of immiscibility and identifies some important molecular characteristics which could lead to the selection of another secondary solvent than dodecane. The decalin seem interesting and its behaviour is studied. A mixing of dodecane and decalin is used as extraction mixing. The obtained results are discussed. Finally, the author notices that using this mixing in the plutonium purification process results in a large increase of metal concentrations and a decrease of risks of crystallisation, without any major drawback, in a continuously operating micro-industrial installation

Pulse radiolysis - new approaches to the classical technique

Energy Technology Data Exchange (ETDEWEB)

Zagorski, Z P [Institute of Nuclear Research, Warsaw (Poland)

1973-01-01

The present status of classical pulse radiolysis is described as well as trends in the further development of this technique (the investigation of radiolysis with nano- and picoseconds time resolution, new optica and electrochemical methods of intermediate species detection). The attention is concentrated on experimental difficulties of particular versions and the achievements are reviewed critically. This paper is the background for experiments being performed in the Institute of Nuclear Research on new techniques of pulse radiolysis.

Determination of plutonium 241 in solutions of nuclear wastes

International Nuclear Information System (INIS)

Raymond, A.; Bilcot, J.B.; Poletiko, C.

1990-09-01

Determination of plutonium 241 in nuclear wastes is important because of long period and high energy of some daughter products. In this report are presented two quantitative analysis methods using both scintillation techniques: A complete method, in any case, by selective extraction of plutonium on an anionic resin allowing simultaneous determination of Pu 241 and the sum of other plutonium isotopes; a simplified method when alpha activity is higher than beta/gamma activity by liquid extraction with TTA. These methods are applied for analysis of 4 waste types: cement encapsulated wastes, bitumen encapsulated wastes, incineration ashes, leaching of encapsulated incineration ashes. In these 4 examples, Pu 241 activity is equal or higher than the sum of alpha plutonium isotope activity. Separation efficiency, measured from Pu 239 or with Pu 236 as tracer, is between 90 and 99% [fr

Current state of knowledge in radiolysis effects on spent fuel corrosion

International Nuclear Information System (INIS)

Christensen, H.; Sunder, S.

1998-09-01

Literature data on the effect of water radiolysis products on spent fuel oxidation and dissolution have been reviewed. Effects of γ-radiolysis, α-radiolysis and dissolved O 2 or H 2 O 2 in unirradiated solutions have been discussed separately. Also the effect of carbonate in γ-irradiated solutions and radiolysis effects on leaching of spent fuels have been reviewed. In addition a radiolysis model for calculation of corrosion rates of UO 2 , presented previously, has been discussed. The model has been shown to give a good agreement between calculated and measured corrosion rates in the case of γ-radiolysis and in unirradiated solutions of dissolved oxygen or hydrogen peroxide. The model has failed to predict the results of α-radiolysis. In a recent study it was shown that the model gave a good agreement with measured corrosion rates of spent fuel exposed in deionized water

Uranium, neptunium and plutonium kinetics of extraction by tributylphosphate and trilaurylamine in a centrifugal contactor

International Nuclear Information System (INIS)

Bergeonneau, P.; Jaouen, C.; Germain, M.; Bathellier, A.

1977-01-01

Uranium, plutonium and neptunium kinetics of transfer between various aqueous nitric solutions and solvents have been measured at the laboratory scale, using a centrifugal contactor especially developed in the laboratory. The transfer kinetics of nitric acid, hexavalent U, tetravalent U, Np and Pu from nitric acid solutions into 30% TBP in r-dodecane and 10% trilaurylamine in r-dodecane have been studied. The effects of rotation speed, temperature, initial nitric acid concentration, metal concentration on extraction and stripping kinetics have been investigated. The results obtained show that TBP extraction and stripping are more rapid than trilaurylamine ones. The low activation energies of transfer reactions with TBP suggest that both in extraction and stripping, the transfer rate is limited by the diffusion of the species in the aqueous and organic phases. For trilaurylamine, the transfer mechanism appears more complex

Recovery of americium-241 from aged plutonium metal

International Nuclear Information System (INIS)

Gray, L.W.; Burney, G.A.; Reilly, T.A.; Wilson, T.W.; McKibben, J.M.

1980-12-01

About 5 kg of ingrown 241 Am was recovered from 850 kg of aged plutonium using a process developed specifically for Savannah River Plant application. The aged plutonium metal was first dissolved in sulfamic acid. Sodium nitrite was added to oxidize the plutonium to Pu(IV) and the residual sulfamate ion was oxidized to nitrogen gas and sulfate. The plutonium and americium were separated by one cycle of solvent extraction. The recovered products were subsequently purified by cation exchange chromatography, precipitated as oxalates, and calcined to the oxides. Plutonium processng was routine. Before cation exchange purification, the aqueous americium solution from solvent extraction was concentrated and stripped of nitric acid. More than 98% of the 241 Am was then recovered from the cation exchange column where it was effectively decontaminated from all major impurities except nickel and chromium. This partially purified product solution was concentrated further by evaporation and then denitrated by reaction with formic acid. Individual batches of americium oxalate were then precipitated, filtered, washed, and calcined. About 98.5% of the americium was recovered. The final product purity averaged 98% 241 AmO 2 ; residual impurities were primarily lead and nickel

Supported extractant membranes for americium and plutonium recovery

International Nuclear Information System (INIS)

Muscatello, A.C.; Navratil, J.D.; Killion, M.E.; Price, M.Y.

1987-01-01

Solid supported liquid membranes(SLM) are useful in transferring and concentrating americium and plutonium from nitrate solutions. Specifically, DHDECMP(dihexyl-N,N-diethylcarbamoylmethylphosphonate) supported on Accurel or Celgard polypropylene hollow fibers assembled in modular form transfers >95% of the americium and >70% of the plutonium from high nitrate (6.9 M), low acid (0.1 M) feeds into 0.25 M oxalic acid stripping solution. Membranes supporting TBP (tri-n-butylphosphate) also transfer these metal ions. Maximum permeabilities were observed to be 1 x 10 -3 cm sec -1 , similar to the values for other systems. The feed:strip volume ratio shows an inverse relationship to the fraction of metal ion transferred. Cation exchangers may be used to concentrate americium from the strip solution

Measurements of plutonium in environmental samples

International Nuclear Information System (INIS)

D'Alberti, F.; Risposi, L.

1996-01-01

Within the activities connected with the start up of the PETRA Laboratory (Processo per l'Estrazione di Terre Rare ed Attinidi, i.e. process for extraction of rare earths and actinides), the Radiation Protection Unit of the J.R.C.-Ispra has carried out a well planned set of experimental measurements aimed at evaluating the zero point of the isotopes of plutonium in environmental samples by alfa spectrometry. After the International Moratorium in 1963, no release of plutonium has occurred in the environment apart from the burn up of SNAP 9A satellite in April 1964. Since then the plutonium concentration in air and in fallout samples has been continuously decreasing requiring, therefore, optimization of both instrumentation and experimental measurement procedures in order to obtain better sensibilities. In this work, the experimental methodology followed at the J.R.C.-Ispra for measurements of plutonium concentration in air, deposition and soil is described and the plutonium behaviour in these samples is reported and discussed starting from 1961

Measurements of plutonium in environmental samples

Energy Technology Data Exchange (ETDEWEB)

D' Alberti, F; Risposi, L [Instituto di Fisica Applicata, University of Milan, Milan (Italy)

1996-01-01

Within the activities connected with the start up of the PETRA Laboratory (Processo per l'Estrazione di Terre Rare ed Attinidi, i.e. process for extraction of rare earths and actinides), the Radiation Protection Unit of the J.R.C.-Ispra has carried out a well planned set of experimental measurements aimed at evaluating the zero point of the isotopes of plutonium in environmental samples by alfa spectrometry. After the International Moratorium in 1963, no release of plutonium has occurred in the environment apart from the burn up of SNAP 9A satellite in April 1964. Since then the plutonium concentration in air and in fallout samples has been continuously decreasing requiring, therefore, optimization of both instrumentation and experimental measurement procedures in order to obtain better sensibilities. In this work, the experimental methodology followed at the J.R.C.-Ispra for measurements of plutonium concentration in air, deposition and soil is described and the plutonium behaviour in these samples is reported and discussed starting from 1961.

Aqueous Chloride Operations Overview: Plutonium and Americium Purification/Recovery

Energy Technology Data Exchange (ETDEWEB)

Gardner, Kyle Shelton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kimball, David Bryan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Skidmore, Bradley Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-09-28

These are a set of slides intended for an information session as part of recruiting activities at Brigham Young University. It gives an overview of aqueous chloride operations, specifically on plutonium and americium purification/recovery. This presentation details the steps taken perform these processes, from plutonium size reduction, dissolution, solvent extraction, oxalate precipitation, to calcination. For americium recovery, it details the CLEAR (chloride extraction and actinide recovery) Line, oxalate precipitation and calcination.

The production control laboratories of the plutonium extraction Plant at Marcoule. Six years operating experience: 1957 - 1963; Les laboratoires de fabrication de l'usine d'extraction du plutonium de Marcoule. Experience des 6 premieres annees de fonctionnement: 1957 - 1963

Energy Technology Data Exchange (ETDEWEB)

Fontaine, A [CEA Marcoule, Centre de Production de Plutonium, 30 (France)

1964-07-01

In this paper, the author attempts to sum up the conditions prevailing, after six years of operation, in the Laboratories of the Plutonium Extraction Plant. The origins and objectives are briefly reviewed, the technology and staff recruitment policy are examined, and progress made is shown. The methods used as well as the scope of application and limits imposed at the present state are considered. Past achievements and further possibilities in the next future are examined. An attempt has been made to bring out the outlooks for the more distant future and to investigate the conditions required for the successful carrying out of the program. (author) [French] Le present rapport tente, apres 6 ans de vie, de faire le point de la situation des Laboratoires du Service Extraction du Plutonium. Apres un rapide retour sur les origines et les objectifs, apres quelques considerations sur le recrutement et la technologie situant le contexte de leurs progres, nous etudierons les methodes, leurs domaines d'application, leurs limites actuelles. Nous ferons un bilan des realisations et des possibilites pour un avenir proche. Nous tenterons de degager quelques vues plus lointaines et les conditions pour les mener a bonne fin. (auteur)

Contribution to the study of liquid-liquid extraction dynamics in the case of fast transfers. Extractions of uranium, plutonium and neptunium in a laboratory centrifugal extractor

International Nuclear Information System (INIS)

Bergeonneau, Philippe

1978-01-01

The liquid-liquid extraction (also named solvent-based extraction) is a very important technique for the reprocessing of irradiated nuclear fuels. This research thesis is based on the use of a laboratory centrifugal extractor which allows interesting conditions to be achieved: fast transfer due to an intense solution mixing, very short duration of contact between solutions. Thus, after a report of a bibliographical study on chemical mechanisms of extraction, on the composition of extracted species, on extraction kinetics, and on centrifugal extractors, this thesis reports the design, fabrication and use of a centrifugal extractor: presentation of fundamental principles, description and characteristics (materials, hydrodynamic operation test and problems, prototype). It reports studies of fast transfer kinetics: mathematical processing, result interpretation, results and discussions of extraction kinetics for nitric acid, uranium VI and IV, plutonium IV, neptunium IV, and comparison of the different extraction kinetics

Evaluation of several novel diamide based ligands for selective extraction of tetravalent plutonium

Energy Technology Data Exchange (ETDEWEB)

Sivaramakrishna, Mallampalli; Nayak, Shashikant K. [Heavy Water Board, V.S. Bhavan, Mumbai (India); Raut, Dhaval R.; Mohapatra, Prasanta K. [Bhabha Atomic Research Center, Mumbai (India). Radiochemistry Division; Nayak, Sandip K. [Bhabha Atomic Research Center, Mumbai (India). Bioorganic Division

2017-06-01

The present paper describes the selective extraction of tetravalent plutonium employing several diamide ligands containing aromatic spacer groups. The ligands containing two amide functional groups attached to a 2,4,6-tri-phenyl pyridine moiety with different substituents viz.; L{sub I} (iso-butyl), L{sub II}(n-butyl), L{sub III}(n-octyl), L{sub IV} (2-ethylhexyl) at the amidic nitrogen atom were evaluated for the extraction of Pu(IV) using their nitrobenzene solutions. The distribution ratio values of Pu(IV) with the diamide ligands followed the order: L{sub II}>L{sub I}>L{sub III}>L{sub IV} and were significantly higher than those of metal ions such as Cs(I), Sr(II), Am(III) and Eu(III). The distribution ratio values of U(VI) were about 2-3 orders magnitude lower than those of Pu(IV). The extraction and stripping kinetics were found to be moderately fast and it took less than 30 min (less than 5 min for L{sub I} and L{sub IV}) to obtain equilibrium D values. The extraction was found to be increasing with the aqueous phase nitric acid concentration conforming to a solvation mechanism of extraction. The extracted species contained two ligand molecules for L{sub I} and L{sub II} while monosolvates were observed for the other two extractants. The ligands showed good radiation stability up to an absorbed dose of 630 kGy.

An analytical method for the determination of plutonium in autopsy samples

International Nuclear Information System (INIS)

Santori, G.

1983-01-01

A sensitive method for the determination of plutonium in autopsy samples is described. After a suitable chemical pretreatment of the samples the plutonium is separated by extraction chromatography with tri-n-octylphosphine oxide (TOPO) supported on microporus polyethylene. After electrodeposition of plutonium the activity is counted by alpha spectroscopy. The global yield was 75-80%. The reagent blank activity was such to allow the determination of some femtocuries of plutonium

High Doses Gamma Radiolysis of PVC: Mechanisms of Degradation

International Nuclear Information System (INIS)

Colombani, J.

2006-01-01

PVC radiolysis leads to the formation of various degradation products: radicals, gas, oxidized products or polyenes. In order to predict the formation of the degradation products with regard to irradiation and ageing parameters, it is important to improve the understanding of the radiolysis mechanisms of PVC. Thus, we used several analytical techniques (Electron Spin Resonance, Fourier Transform Infrared spectroscopy, Nuclear Magnetic Resonance, Size Exclusion Chromatography) to get information on PVC samples irradiated at high doses (up to 4MGy) under different conditions. Gamma irradiation induces the formation of various radicals into PVC. Older studies were generally focused on the effect of low dose and/or low temperature irradiations on PVC. We present here ESR signals of PVC irradiated at high doses and at room temperature. We show that peroxyl radicals are producted by radiolysis under aerobe conditions and that polyenyl radicals are formed under anaerobe conditions. PVC radiolysis induces gas production and especially hydrogen chloride. Production of hydrogen chloride is well known until 1 MGy. We have studied by FTIR, the evolution of the quantity of HCl produced until 4 MGy. We show that higher irradiation dose leads to the lower radiolytic yield of HCl (G(HCl)). Moreover, G(HCl) obtained in aerobe conditions is about fourfold as great as G(HCl) observed in anaerobe radiolysis. Propagation and termination reactions induce degradation products: polyene sequences and crosslinking reactions are observed under anaerobe conditions; oxidized products with addition of chain scissions are formed under aerobe conditions. Although the literature about PVC radiolysis is rich, the main reacting pathways are not well established. Moreover the high doses studies are almost non-existent. We show by FTIR that aerobe radiolysis induces formation of ketons and acids. NMR experiments confirme these results but also focuse on small acids formed (with 2, 3 or 4 carbons). The

Plutonium Chemistry in the UREX Separation Processes

International Nuclear Information System (INIS)

Paulenova, Alena; Vandegrift, George F. III; Czerwinski, Kenneth R.

2009-01-01

The objective of the project is to examine the chemical speciation of plutonium in UREX+ (uranium/tributylphosphate) extraction processes for advanced fuel technology. Researchers will analyze the change in speciation using existing thermodynamics and kinetic computer codes to examine the speciation of plutonium in aqueous and organic phases. They will examine the different oxidation states of plutonium to find the relative distribution between the aqueous and organic phases under various conditions such as different concentrations of nitric acid, total nitrates, or actinide ions. They will also utilize techniques such as X-ray absorbance spectroscopy and small-angle neutron scattering for determining plutonium and uranium speciation in all separation stages. The project started in April 2005 and is scheduled for completion in March 2008.

Effect of nitrogen and oxygen on radiolysis of iodide solution

Energy Technology Data Exchange (ETDEWEB)

Karasawa, H; Endo, M [Hitachi Ltd., Power and Industrial System R+D Divisions, Ibaraki (Japan)

1996-12-01

The effect of nitrogen and oxygen on radiolysis of iodide solution was examined. Direct decomposition of nitrogen by {gamma}-radiation produced nitric acid to decrease a water pH. This resulted in the iodine formation in the radiolysis of iodide solution. Hydrogen peroxide was produced by the radiolysis of water containing oxygen. This worked a reducing agent to suppress the formation of iodine in the radiolysis of iodide solution. In the analytical model, fourteen iodine species were considered and reaction scheme consisted in 124 reactions. The analytical model could estimate the oxidation state of iodide ions. (author) 4 figs., 4 refs.

The analysis of radiolysis impurities in 18F-FDG and methods of repurification

International Nuclear Information System (INIS)

Jinming Zhang; Yungang Li; Jian Liu; Xiaojun Zhang; Jiahe Tian

2010-01-01

To investigate the radio impurity in the radiolysis of 18 F-FDG at high radiodose and radioconcentrated solutions and develop methods of repurification. The radiolysis of 18 F-FDG was analyzed by TLC. The radio-impurity was confirmed by biodistribution and small animal PET/CT studies. 18 F-FDG was unstable at high radioconcentration over 37 GBq/mL or under basic condition. TLC, biodistribution and PET/CT all indicated that the main autoradiolysis byproduct was free fluoride ion. The radiolyzed 18 F-FDG was repurified by solid-phase extraction (SPE) column. The repurified 18 F-FDG had a radiochemical purity (RCP) of over 99% and significantly lower bone uptake than that was before repurification (P = 0.0003). There was a positive correlation between the recovery yield and the purity of 18 F-FDG (R 2 = 0.66). (author)

Testing requirements for SCWR radiolysis

International Nuclear Information System (INIS)

Guzonas, D.; Stuart, C.; Jay-Gerin, J.-P.; Meesungnoen, J.

2010-01-01

The Generation IV supercritical water-cooled reactor (SCWR) designs under consideration would operate at ∼430-625 o C and 25 MPa, i.e., well beyond the thermodynamic critical point of water. Supercritical (light/heavy) water (SCW)-cooled reactors would enable thermodynamic cycle efficiencies as high as ∼44% (versus ∼33% for existing water reactors), thus generating lower-cost electricity. The purpose of this report is to survey the literature on SCW radiolysis, describe the recent modeling performed at the Universite de Sherbrooke, and to broadly outline the testing required to develop a benchmarked SCW radiolysis model. (author)

Picosecond pulse radiolysis studies to understand the primary processes in radiolysis

International Nuclear Information System (INIS)

Jonah, C.D.; Lewis, M.A.

1984-01-01

The use of pulse radiolysis to learn about processes which occur before the beginning of chemical times is discussed. Two examples, the distance distribution of positive and negative ions in hydrocarbons, and the state of the dry electron are discussed in detail

Picosecond pulse radiolysis studies to understand the primary processes in radiolysis

Energy Technology Data Exchange (ETDEWEB)

Jonah, C.D.; Lewis, M.A.

1984-01-01

The use of pulse radiolysis to learn about processes which occur before the beginning of chemical times is discussed. Two examples, the distance distribution of positive and negative ions in hydrocarbons, and the state of the dry electron are discussed in detail.

Review of major plutonium pyrochemical technology

International Nuclear Information System (INIS)

Moser, W.S.; Navratil, J.D.

1983-01-01

The past twenty years have seen significant growth in the development and application of pyrochemical technology for processing of plutonium. For particular feedstocks and specific applications, non-aqueous high-temperature processes offer key advantages over conventional hydrometallurgical systems. Major processes in use today include: (1) direct oxide reduction for conversion of PuO 2 to metal, (2) molten salt extraction for americium removal from plutonium, (3) molten salt electrorefining for Pu purification, and (4) hydriding to remove plutonium from host substrates. This paper reviews current major pyrochemical processes from the classical calcination-hydrofluorination-bomb reduction sequence through new techniques under development. Each process is presented and brief descriptions of production equipment are given. 47 references, 5 figures

CONVERSION OF PLUTONIUM TRIFLUORIDE TO PLUTONIUM TETRAFLUORIDE

Science.gov (United States)

Fried, S.; Davidson, N.R.

1957-09-10

A large proportion of the trifluoride of plutonium can be converted, in the absence of hydrogen fluoride, to the tetrafiuoride of plutonium. This is done by heating plutonium trifluoride with oxygen at temperatures between 250 and 900 deg C. The trifiuoride of plutonium reacts with oxygen to form plutonium tetrafluoride and plutonium oxide, in a ratio of about 3 to 1. In the presence of moisture, plutonium tetrafluoride tends to hydrolyze at elevated temperatures and therefore it is desirable to have the process take place under anhydrous conditions.

Determination of plutonium in air and smear samples

International Nuclear Information System (INIS)

Hinton, E.R. Jr.; Tucker, W.O.

1981-01-01

A method has been developed for the determination of plutonium in air samples and smear samples that were collected on filter papers. The sample papers are digested in nitric acid, extracted into 2-thenoyltrifluoroacetone (TTA)-xylene, and evaporated onto stainless steel disks. Alpha spectrometry is employed to determine the activity of each plutonium isotope. Each sample is spiked with plutonium-236. All glassware used in the procedure is disposable. The detection limits are 3 and 5 dpm (disintegrations per minute) for air and smear samples, respectively, with an average recovery of 87%

Current state of knowledge of water radiolysis effects on spent nuclear fuel corrosion

International Nuclear Information System (INIS)

Christensen, H.; Sunder, S.

2000-07-01

Literature data on the effect of water radiolysis products on spent-fuel oxidation and dissolution are reviewed. Effects of gamma radiolysis, alpha radiolysis, and dissolved O 2 or H 2 O 2 in unirradiated solutions are discussed separately. Also, the effect of carbonate in gamma-irradiated solutions and radiolysis effects on leaching of spent fuel are reviewed. In addition, a kinetic model for calculating the corrosion rates of UO 2 in solutions undergoing radiolysis is discussed. The model gives good agreement between calculated and measured corrosion rates in the case of gamma radiolysis and in unirradiated solutions containing dissolved oxygen or hydrogen peroxide. However, the model fails to predict the results of alpha radiolysis. In a recent study , it was shown that the model gave good agreement with measured corrosion rates of spent fuel exposed in deionized water. The applications of radiolysis studies for geologic disposal of used nuclear fuel are discussed. (author)

Pulse radiolysis study of egg white

International Nuclear Information System (INIS)

Micic, O.I.; Josimovic, L.; Markovic, V.

1978-01-01

Radiolytic processes in egg white in intervals of 0.1μs to several seconds have been studied by the pulse radiolysis technique. The formation and decay of short-lived intermediates and their absorption spectra were observed under varied experimental conditions. The results show that intermediates are produced predominantly in reactions of radicals formed in water radiolysis with egg white proteins. The intermediates decay mainly in the first-order intermolecular processes, though the mechanism of transformations is very complex. (author)

Plutonium Chemistry in the UREX+ Separation Processes

Energy Technology Data Exchange (ETDEWEB)

ALena Paulenova; George F. Vandegrift, III; Kenneth R. Czerwinski

2009-10-01

The project "Plutonium Chemistry in the UREX+ Separation Processes” is led by Dr. Alena Paulenova of Oregon State University under collaboration with Dr. George Vandegrift of ANL and Dr. Ken Czerwinski of the University of Nevada at Las Vegas. The objective of the project is to examine the chemical speciation of plutonium in UREX+ (uranium/tributylphosphate) extraction processes for advanced fuel technology. Researchers will analyze the change in speciation using existing thermodynamics and kinetic computer codes to examine the speciation of plutonium in aqueous and organic phases. They will examine the different oxidation states of plutonium to find the relative distribution between the aqueous and organic phases under various conditions such as different concentrations of nitric acid, total nitrates, or actinide ions. They will also utilize techniques such as X-ray absorbance spectroscopy and small-angle neutron scattering for determining plutonium and uranium speciation in all separation stages. The project started in April 2005 and is scheduled for completion in March 2008.

Characterisation and activation of catalysts for recombination of radiolysis gas

International Nuclear Information System (INIS)

Bolz, Michael; Koehler, Jan; Schorle, Rolf; Helf, Achim

2011-01-01

Radiolysis gas is produced by radiolysis of cooling water during the operation of boiling water reactors. Small amounts of radiolysis gas can accumulate at dead ends of pipes in the water-steam circuit. Under certain conditions, it can accumulate even to higher concentrations. To avoid these accumulations, small catalysts are built in. As part of a diploma thesis, the catalysts were analysed and characterised. (orig.)

Pulse radiolysis of gases

International Nuclear Information System (INIS)

Nielsen, O.J.

1984-04-01

The pulse radiolysis equipment and technique are described and its relevance to atmospheric chemistry is discussed. Pulse radiolysis of a number of different chemical systems have been used to check the validity of the proposed mechanisms: 1) The hydrogen atom yield in the pulse radiolysis of H 2 was measured by four independent calibration techniques, using reactions of H with O 2 , C1NO, and HI. The H atom yield was compared with O 2 yields in pure O 2 and in O 2 /SF 6 mixtures which lead to a value G(H) = 17.6. The rate constants at room temperature of several reactions were determined. 2) OH radical reactions with tetraalkyllead at room temperature and with ethane, methane, and a series of C1- and F-substituted methanes at 300-400 K were studied. Arrhenius parameters, A and Esub(a), were determined for several reactions. The lifetime of Pb(CH 3 ) 4 and Pb(C 2 H 5 ) 4 in ambient air is estimated. CF 2 C1 2 was found to be a very efficient third body, M, in the reaction OH + OH + M arrow H 2 O 2 + M. 3) In the H 2 S systems the HS extinction coefficient at 3242 AA was determined to 9.5 x 10 2 cm -1 mol -1 . Four rate constants at room temperature were determined. (author)

Reduction stripping of plutonium (IV) with hydroxylamine nitrate in the centrifugal contactor

International Nuclear Information System (INIS)

Zhang Zefu; Ding Dachun; Fei Hongcheng

1989-01-01

Reduction stripping of Pu(IV) with hydroxylamine nitrate under conditions of Purex 3B contactor is carried out with 16-stage mixer-centrifugal settler in laboratory scale. Results show that the apparent recovery of Pu is more than 99.9%. But there is a great difference in the concentration of plutonium of every stage in extraction equipment at different temperature. For example, plutonium concentrations in organic phase of several stages near the organic effluent at 45-50 deg C are lower than that at 20-24 deg C. Thus, recovery efficiency of plutonium can be assured only for the former. However, plutonium will probably be lost, if operating conditions are fluctuated. In addition, plutonium accumulated in the extraction equipment increased appreciably for the case of 20-24 deg C. Therefore, in order to ensure recovery efficiency of Pu, reduction stripping of Pu should be made at higher temperature

Radiolysis of dilute aqueous solutions of cesium iodide

International Nuclear Information System (INIS)

Gorbovitskaya, T.I.; Galinkin, D.L.; Kants, L.K.; Tiliks, Yu.E.; Kotelkin, I.M.; Luzanova, L.M.

1993-01-01

Study of physical-chemical processes in the NPP containment by severe accident is carried out. Radiolysis of reactor cooling water containing iodine and cesium radionuclides penetrated therein in the course of accident is considered as of such processes. Role of ionizing radiation in the process of formation and release of ecologically hazardous volatile forms of radioiodine from reactor water into environment is studied. Experiments on radiolysis of CsI diluted water solutions are carried out. The data obtained were used for clarification of radiolysis mechanism for iodine-containing water system, enabling forecast of iodine behaviour in the course of the accident. 5 refs., 4 figs., 1 tab

Radical production in the radiolysis of benzene

International Nuclear Information System (INIS)

LaVerne, J.A.; Araos, M.S.

1998-01-01

Complete text of publication follows. Benzene is the prototypical aromatic compound and yet the radiation chemistry of the radicals formed in its radiolysis is not well understood. Temporal information on the yield of phenyl radical, the major radical produced in the radiolysis, is important for understanding the radiation chemistry of many other types of aromatic compounds including some polymers. The effects of track structure on the production of phenyl radicals have been examined using iodine-scavenging techniques. The variation of the yields of iodobenzene and the other major molecular products such as biphenyl as a function of iodine concentration gives a good indication of the competition kinetics occurring in particle tracks. Experimental results of the scavenger experiments will be shown and their implications in the radiolysis of condensed hydrocarbons will be discussed

Robotic sample preparation for radiochemical plutonium and americium analyses

International Nuclear Information System (INIS)

Stalnaker, N.; Beugelsdijk, T.; Thurston, A.; Quintana, J.

1985-01-01

A Zymate robotic system has been assembled and programmed to prepare samples for plutonium and americium analyses by radioactivity counting. The system performs two procedures: a simple dilution procedure and a TTA (xylene) extraction of plutonium. To perform the procedures, the robotic system executes 11 unit operations such as weighing, pipetting, mixing, etc. Approximately 150 programs, which require 64 kilobytes of memory, control the system. The system is now being tested with high-purity plutonium metal and plutonium oxide samples. Our studies indicate that the system can give results that agree within 5% at the 95% confidence level with determinations performed manually. 1 ref., 1 fig., 1 tab

The application of N,N-dimethylhydroxylamine as reductant for the separation of plutonium from uranium

International Nuclear Information System (INIS)

Jinping Liu; Hui He; Hongbin Tang; Yanxin Chen

2011-01-01

Both single stage and multi-stages experiments on stripping plutonium with N,N-dimethylhydroxylamine (DMHAN) as reductant with methylhydrozine (MMH) as supporting reductant were carried out. The effect of contact time, temperature, acidity, concentration of DMHAN on back-extraction rate of plutonium was investigated in the single stage experiment. The results demonstrated that the reaction of stripping Pu(IV) in the organic phase (30% TBP-kerosene) 1BF solutions by DMHAN exhibits excellent stripping efficiency. Under the given conditions, the back-extraction rate of plutonium reaches 90% within 2 min. Higher temperature, lower acidity and the increased concentration of DMHAN benefit the stripping reaction. The concentration profile of HNO 3 , uranium and plutonium were determined in a multi-stages mixer-settler after the steady state of the back-extraction, and the multi-stages results show that the plutonium can be separated effectively from uranium. The recovery of plutonium and uranium reach 99.995% or over 99.99% respectively. The separation factor of U from Pu (SF Pu/U ) is about 2 x 10 4 . (author)

Ultra trace plutonium isotopic analyse by thermo ionization mass spectrometry

International Nuclear Information System (INIS)

Liu Xuemei; Long Kaiming; Yang Tianli

2008-06-01

An anion exchange combined with TTA extraction decontamination method was established. The nanogram quantity Plutonium was separated from milligram uranium and the decontamination coefficient achieved 10 7 , the recovery coefficient >95%. The active carbon powder was chosen as the ionization intensifier to increase the plutonium ion flow. Used 6.7 pg Plutonium standard as sample to measured by TIMS and the RSD of the 240 Pu/ 239 Pu ≤3.6%. (authors)

Pulse radiolysis of 9,10-anthraquinone in methanol

International Nuclear Information System (INIS)

Mayer, J.; Krasiukianis, R.

1990-01-01

The reactions of anthraquinone with intermediates in methanol (e 2 - , . CH 2 O - , . CH 2 OH) were investigated using γ-radiolysis and pulse radiolysis method. The anthraquinone radical anions are reactive towards O 2 (ca 3 x 10 8 mol -1 dm 3 s -1 ) and can disproportionate giving corresponding dianion. (author)

Radiolysis of concentrated solutions. 2. Pulse and #betta#-radiolysis studies of direct and indirect effects in lithium iodide solutions

International Nuclear Information System (INIS)

Hadjadj, A.; Julien, R.; Pucheault, J.; Ferradini, C.; Hickel, B.

1982-01-01

In the preceding study of the radiolysis of concentrated aqueous LiCl solutions, one of the hypotheses used to explain the apparent inefficacy of Cl 2- formation by the direct effect was that molecular chlorine, not detectable by spectrophotometry, could be formed during the early stages of water radiolysis. Such an hypothesis is confirmed here for pulse and #betta#-radiolysis of concentrated aqueous neutral LiI solutions. Indeed, it is shown that, 10 ns after the pulse, molecular iodine, detected as I 3- , is formed with a yield that increases with the LiI concentration. The experimental results yields values of 4.8 and 7.3 respectively for the indirect and direct effects of total oxidation G/sub I 2- / + 2G/sub I 3- /. This last high value is discussed

Radiolysis of phenol in aqueous solution at elevated temperatures

International Nuclear Information System (INIS)

Miyazaki, Toyoaki; Katsumura, Yosuke; Lin Mingzhang; Muroya, Yusa; Kudo, Hisaaki; Taguchi, Mitsumasa; Asano, Masaharu; Yoshida, Masaru

2006-01-01

γ-Radiolysis and pulse radiolysis of phenol in aqueous solution up to supercritical condition have been carried out. G-values of phenol consumption and product formation have been determined. While dihydroxybenzenes were major products at room temperature, multi-ring compounds and benzene were formed above 300 deg. C. This indicates reaction mechanism was changed above 300 deg. C, where phenoxyl radical plays a predominant role. This is supported by the observation of phenoxyl radical in pulse radiolysis. In supercritical water, the G-values increased with decrease of density

Radiolysis of anthraquinone dyes in aqueous solutions

International Nuclear Information System (INIS)

Vysotskaya, N.A.; Bortun, L.N.; Ogurtsov, N.A.; Migdalovich, E.A.; Revina, A.A.; Volodko, V.V.; AN SSSR, Moscow. Inst. Ehlektrokhimii)

1986-01-01

The commercial anthraquinone dyes (Dark Blue, Light Blue, Green) in aqueous solutions were shown to be decoloured and degrade under the action of ionizing radiation. The degree of decolouration and degradation of aromatic rings was found to increase in presence of oxygen. Hydroxyl radicals were shown to play the key role in the degradation of the dyes under irradiation. The radiolysis intermediate products were studied using the pulse radiolysis technique. (author)

Study on radiolysis products of N,N,N',N'-tetrabutyl-3-oxa-pentanediamide. Pt.1: Qualitative and quantitative analysis of dibutylamine

International Nuclear Information System (INIS)

Zhang Xiaolan; Shanghai Univ., Shanghai; Bao Borong; Shanghai Univ., Shanghai; Yang Yanqin; Ye Guoan; Zhang Xianye

2005-01-01

The study on radiolysis products of gamma-irradiated N,N,N',N'-tetrabutyl-3-oxa-pentane-diamide (TBOPDA) is very useful towards the extractant stability. IR and headspace solid-phase microextraction combined with gas chromatography/mass spectrometry (SPME-GC/MS) are used in the research. By comparisons with standard substances, dibutylamine and N,N-dibutylformamide are comfirmed to be the major radiolysis products. The influences of irradiation on TBOPDA and dibutylamine are quantitated by using headspace SPME-GC and HPLC. According to the experiment results, the possible ways of degradation are also proposed. (authors)

Calculating the plutonium in spent fuel elements

International Nuclear Information System (INIS)

Barnham, Keith

1992-01-01

Many members of the public are concerned about plutonium. They are worried about its environmental, health and proliferation risks. Fundamental to all such considerations are two related questions: how much plutonium do nuclear reactors produce ? and how accurately do the relevant authorities know these production figures ? These two questions have been studied with particular reference to the UK civil Magnox reactors. In 1990 these were still the only UK civil reactors whose spent fuel had been reprocessed to extract plutonium in routine production. It has not been possible to conclude that the relevant government industry and safeguard authorities are aware of how much plutonium these reactors produce and that the figures are known to the highest achievable accuracy. To understand why, this chapter will outline some of the history of the attempts to get answers to these two questions. (author)

Direct reduction of plutonium from dicesium hexachloroplutonate

International Nuclear Information System (INIS)

Averill, W.A.; Boyd, T.E.

1991-01-01

The Rocky Flats Plant produces dicesium hexachloroplutonate (DCHP) primarily as a reagent in the molten salt extraction of americium from plutonium metal. DCHP is precipitated from aqueous chloride solutions derived from the leaching of process residues with a high degree of selectivity. DCHP is a chloride salt of plutonium, while the traditional aqueous precipitate is a hydrated oxide. Plutonium metal preparation from the oxide involves either the conversion of oxide to a halide followed by metallothermic reduction or direct reduction of the oxide using a flux. Either method generates at least three times as much radioactively contaminated waste as metal produced. Plutonium concentration by DCHP precipitation, however, produces a chloride salt that can be reduced using calcium metal at a temperature of approximately 1000K. In this paper the advantages and limitations of this process are discussed

Studies on oxidative radiolysis of ibuprofen in presence of potassium persulfate

International Nuclear Information System (INIS)

Paul, Jhimli; Naik, D.B.; Bhardwaj, Y.K.; Varshney, Lalit

2014-01-01

The radiolysis of ibuprofen (IBP), a model pharmaceutical compound, was studied by gamma irradiation in an aqueous solution in the presence and absence of potassium persulfate (K 2 S 2 O 8 ). The extent of mineralization was investigated by measuring the UV–visible spectra, decrease in the chemical oxygen demand (COD) and the total organic carbon (TOC) content of aqueous IBP solution at different doses. The gamma radiolysis, in the presence of K 2 S 2 O 8 , required much lesser dose compared to in the absence of K 2 S 2 O 8 for the same extent of mineralization of aqueous IBP solution. The pulse radiolysis of IBP was carried out under different radiolytic conditions to understand the mechanism of efficient mineralization of IBP during gamma radiolysis in the presence of K 2 S 2 O 8 . It was found that unlike · OH radical, SO 4 ·− radical preferentially produces benzyl type of radicals via the formation of the benzene radical cation. The results concluded that the gamma radiolysis in presence of K 2 S 2 O 8 could be one of the efficient advanced oxidation processes for degradation of pharmaceutical compounds present in the aqueous solution. - Highlights: • The radiolysis of aqueous solution of Ibuprofen (IBP) was investigated. • The COD and TOC content decreased significantly in presence of K 2 S 2 O 8 . • Pulse radiolysis studies revealed the mechanism of mineralization of IBP. • The presence of K 2 S 2 O 8 increased the efficiency of gamma radiolysis

Study of water radiolysis in porous media

International Nuclear Information System (INIS)

Rotureau, Patricia

2001-08-01

The understanding of the production of H 2 in the radiolysis of water confined into pores of concrete is important for the disposal of radioactive waste. In order to describe the mechanisms of water radiolysis in such heterogeneous porous systems we have studied the behaviour under gamma radiation of water confined in porous silica glasses with pores going from 8 to 300 nm of diameter and meso-porous molecular sieves (MCM-41). The radiolytic yields of hydroxyl radicals, hydrated electron and dihydrogen, have been determined with respect to the pore size of materials. The increase of these radiolytic yields compared to those of free water allowed us to show a charge transfer from silica to confined water. On the other hand the kinetics of hydrated electron reactions measured by pulse radiolysis are not modified. (author) [fr

Formation of stable radicals during perfluoroalkane radiolysis

International Nuclear Information System (INIS)

Allayarov, S.R.; Demidov, S.V.; Kiryukhin, D.P.; Mikhajlov, A.I.; Barkalov, I.M.

1984-01-01

Accumulation and stabilization kinetics of perfluoroalkyls during α-radiolysis ( 60 Co) of perfluoralkanes (PFA) in a wide temperature range for different PFA fractions differing in the average molecular weight, is investigated. It is noted that low temperature (PFA) radiolysis (77 K) is of a linear nature of accumulation of stabilized radicals up to doses of approximately 700 KGy. In the case of PFA radiolysis at 300 K radiation yields of stable radicals are somewhat lower than at 47 K and at doses of 200-300 KGy, their accumulation ceases. It is shown that kinetics of formation and accumulation of stable radicals does not depend on molecular mass and PFA fraction viscosity. Perfluoroalkyl stability is explained by intra molecular conformation spheric insulation of the free valency. Perfluoroalkyl stability in different PFA fractions in a wide time range in different media is investigated

Proton Pulse Radiolysis

Energy Technology Data Exchange (ETDEWEB)

Christensen, H C; Nilsson, G; Reitberger, T; Thuomas, K A

1973-03-15

A 5 MeV proton accelerator (Van de Graaff) has been used for pulse radiolysis of a number of organic gases and the transient spectra obtained from the alkanes methane, ethane, propane, n-butane and neopentane have tentatively been assigned to alkyl radicals. Some methodological aspects of this new technique are discussed

Subpicosecond pulse radiolysis studies on spur reactions and nanotechnology

International Nuclear Information System (INIS)

Tagawa, S.

2003-01-01

Recently we developed a subpicosecond pulse radiolysis system, although the time resolution of pulse radiolysis had remained about 30 ps for these 30 years. Time resolution and S/N ratio have been improved dramatically. The subpicosecond pulse radiolysis is a very powerful method to detect and observe transient phenomena in radiation chemistry and physics within 30 ps. By using the subpicosecond pulse radiolysis, many researches have been carried out on ultrafast phenomena in radiation chemistry, physics, biology and applied fields such as material science.Especially the spur reaction, which is one of the most important reactions in radiation chemistry, physics and biology, has been studied in the very wide time range from subpicosecond to several hundred nanoseconds by very high S/N ratio. These experimental results were analyzed theoretically and applied to the basic data for nanofabrication, which are very important in both next generation lithography and nanotechnology

Functional design criteria for the 242-A evaporator and PUREX [Plutonium-Uranium Extraction] Plant condensate interim retention basin

International Nuclear Information System (INIS)

Cejka, C.C.

1990-01-01

This document contains the functional design criteria for a 26- million-gallon retention basin and 10 million gallons of temporary storage tanks. The basin and tanks will be used to store 242-A Evaporator process condensate, the Plutonium-Uranium Extraction (PUREX) Plant process distillate discharge stream, and the PUREX Plant ammonia scrubber distillate stream. Completion of the project will allow both the 242-A Evaporator and the PUREX Plant to restart. 4 refs

Plutonium separation and the measurement of its concentration in natural waters (1963); Separation du plutonium et mesure de sa concentration dans les eaux naturelles

Energy Technology Data Exchange (ETDEWEB)

Scheidhauer, J; Messainguiral, L; Meiraneisio, A M [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

1963-07-01

After concentration by chemisorption on a calcium fluoride suspension, the plutonium is purified and isolated by xylene extraction of the complex formed with T.T.A. The radioelement is measured by counting with a ZnS (Ag) scintillator after evaporation or electrolysis. (authors) [French] Apres concentration par chimisorption sur une suspension de fluorure de calcium, le plutonium est purifie et isole par extraction au xylene du complexe forme avec la T.T.A. La mesure du radioelement est effectuee par comptage au scintillateur S Zn (Ag) apres evaporation ou electrolyse. (auteurs)

Heavy water radiolysis and chemistry control of the Fugen Nuclear Power Station

International Nuclear Information System (INIS)

Ibuki, Y.; Kitabata, T.; Kato, T.

1989-01-01

A computer analysis for heavy water radiolysis clarified the mechanism of the heavy water radiolysis rate change with impurities in the heavy water and cover gas, helium. The mechanism is supported by over ten years' operational data of the heavy water radiolysis in the Fugen nuclear power station. (author)

Template measurement for plutonium pit based on neural networks

International Nuclear Information System (INIS)

Zhang Changfan; Gong Jian; Liu Suping; Hu Guangchun; Xiang Yongchun

2012-01-01

Template measurement for plutonium pit extracts characteristic data from-ray spectrum and the neutron counts emitted by plutonium. The characteristic data of the suspicious object are compared with data of the declared plutonium pit to verify if they are of the same type. In this paper, neural networks are enhanced as the comparison algorithm for template measurement of plutonium pit. Two kinds of neural networks are created, i.e. the BP and LVQ neural networks. They are applied in different aspects for the template measurement and identification. BP neural network is used for classification for different types of plutonium pits, which is often used for management of nuclear materials. LVQ neural network is used for comparison of inspected objects to the declared one, which is usually applied in the field of nuclear disarmament and verification. (authors)

Fundamental Aspects of Water Coolant Radiolysis

International Nuclear Information System (INIS)

Christensen, Hilbert

2006-04-01

The current state of knowledge of radiolysis in Light Water Reactors (LWR) is presented in this report. High-temperature data for rate constants and primary radiolysis yields have been collected and are shown in tables. Data from different sources have been compared and based on this recommended values have been selected. There is generally a good agreement between g-values for gamma-radiation at ambient temperature from different sources. There are larger discrepancies between results for primary yields from fast neutrons and also for g-values at reactor temperatures. Complete reaction mechanisms, including rate constants at reactor temperatures, from different sources are discussed and shown in tables. Experimentally determined activation energies are also shown, including the temperature range within which they have been determined. In normal cases rate constants at high temperature have been calculated from the rate constant at ambient temperature and the activation energy. Exceptions from this rule are shown and uncertainties have been discussed. The results of a number of radiolysis calculations, carried out for reactor temperatures, are also shown. The results of some sensitivity analyses are discussed. It has been shown that results from radiolysis calculations are rather sensitive to the rate constant ratio k(OH + H 2 )/(k(OH + H 2 O 2 ). The first reaction leads to recombination, whereas the last reaction leads to decomposition. In some cases reactions which are unimportant at ambient temperature may play a role at reactor temperatures. This may be the case for reactions with a low rate constant at ambient temperature in combination with a high activation energy

X-ray diffraction study of pure plutonium under pressure

Energy Technology Data Exchange (ETDEWEB)

Faure, Ph. [CEA, Valduc, F-21120 Is-sur-Tille (France)], E-mail: philippe.faure@cea.fr; Genestier, C. [CEA, Valduc, F-21120 Is-sur-Tille (France)

2009-03-15

Atomic volume and bulk modulus represent basic cohesion properties of a material and are therefore linked to many other physical properties. However, large discrepancies are found in the literature regarding values for the bulk modulus of pure plutonium ({alpha}-phase). New X-ray diffraction measurements of plutonium in diamond anvil cell are presented and the isothermal bulk modulus is extracted.

Development of subpicosecond pulse radiolysis system

CERN Document Server

Kozawa, T; Miki, M; Yamamoto, T; Suemine, S; Yoshida, Y; Tagawa, S

2000-01-01

The highest time resolution of the pulse radiolysis had remained about 30 ps since the late 1960s. To make clear the primary processes in the radiation chemistry and physics within 30 ps, we developed a stroboscopic pulse radiolysis system for the absorption spectroscopy with the time resolution of 2.0 ps (10-90% rise time). The time resolution of 2.0 ps was estimated from the time-dependent behavior of the hydrated electrons. The system consists of a subpicosecond electron linac as an irradiation source, a femtosecond laser as an analyzing light and a jitter compensation system.

Plutonium in nature; Le plutonium dans la nature

Energy Technology Data Exchange (ETDEWEB)

Madic, C.

1994-12-31

Plutonium in nature comes from natural sources and anthropogenic ones. Plutonium at the earth surface comes principally from anthropogenic sources. It is easily detectable in environment. The plutonium behaviour in environment is complex. It seems necessary for the future to reduce releases in environment, to improve predictive models of plutonium behaviour in geosphere, to precise biological impact of anthropogenic plutonium releases.

γ-radiolysis of benzophenone in heptane solutions

International Nuclear Information System (INIS)

Melekhonova, I.I.; Romantsev, M.F.; Saraeva, V.V.

1979-01-01

The radiolysis mechanism of 8x10 -3 M solutions of benzophenon in heptane at 0 deg C and a dose of 3.8x10 20 eV/ml, is studied. The radiolysis products (benzpinacol and benzhydrol with alkyl substitution in aromatic ring) are isolated by the thin-layer chromatography. The identification of the products is performed using infrared and mass spectroscopy. The mechanism of the process is considered based on the reactions of a triplet state of benzophenon

Synergistic extraction of hexavalent plutonium by HTTA and HPMBP using mono- and bi- functional neutral donors: a comparative study

International Nuclear Information System (INIS)

Lohithakshan, K.V.; Mithapara, P.D.; Pai, S.A.; Aggarwal, S.K.

1997-01-01

Thermodynamics and synergistic extraction of hexavalent plutonium were studied from HNO 3 medium (0.05M) with HTTA and HPMBP and various neutral donors viz. DPSO, TBP, TOPO (monofunctional) and DBDECMP, DHDECMP, CMPO (bifunctional) using benzene as a diluent. The net enthalpy and entropy changes were interpreted in terms of different organic phase adduct formation reaction mechanisms i.e. substitution in HTTA vs addition in HPMBP. (author). 4 refs., 2 figs

Characterization of plutonium-bearing wastes by chemical analysis and analytical electron microscopy

International Nuclear Information System (INIS)

Behrens, R.G.; Buck, E.C.; Dietz, N.L.; Bates, J.K.; Van Deventer, E.; Chaiko, D.J.

1995-09-01

This report summarizes the results of characterization studies of plutonium-bearing wastes produced at the US Department of Energy weapons production facilities. Several different solid wastes were characterized, including incinerator ash and ash heels from Rocky Flats Plant and Los Alamos National Laboratory; sand, stag, and crucible waste from Hanford; and LECO crucibles from the Savannah River Site. These materials were characterized by chemical analysis and analytical electron microscopy. The results showed the presence of discrete PuO 2 PuO 2-x , and Pu 4 O 7 phases, of about 1μm or less in size, in all of the samples examined. In addition, a number of amorphous phases were present that contained plutonium. In all the ash and ash heel samples examined, plutonium phases were found that were completely surrounded by silicate matrices. Consequently, to achieve optimum plutonium recovery in any chemical extraction process, extraction would have to be coupled with ultrafine grinding to average particle sizes of less than 1 μm to liberate the plutonium from the surrounding inert matrix

Breaking time-resolution limits in pulse radiolysis

International Nuclear Information System (INIS)

Yang Jinfeng; Kondoh, Takafumi; Norizawa, Kimihiro; Yoshida, Yoichi; Tagawa, Seiichi

2009-01-01

Pulse radiolysis, which is a time-resolved stroboscopic method based on ultrashort electron pulse and ultrashort analyzing light, is widely used for the study of the chemical kinetics and radiation primary processes or reactions. Although it has become possible to use femtosecond-pulse electron beam and femtosecond laser light in pulse radiolysis, the resolution is limited by the difference in group velocities of the electrons and the light in sample. In this contribution, we introduce a concept of equivalent velocity spectroscopy (EVS) into pulse radiolysis and demonstrate the methodology experimentally. In EVS, both the electron and the analyzing light pulses precisely overlap at every point in the sample and throughout the propagation time by rotating the electron pulse. The advance allows us to overcome the resolution degradation due to the different group velocity. We also present a method for measuring the rotated angle of the electron pulse and a technique for rotating the electron pulse with a deflecting cavity.

Preparation of plutonium fluoride to obtain metal of high purity; Preparation de fluorures de plutonium pour l'obtention de metal de haute purete

Energy Technology Data Exchange (ETDEWEB)

Faugeras, P; Brut, A; Helou, R [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

In the process of treating irradiated uranium, plutonium can be separated from the majority of the fission products and from the uranium by TBP extraction cycles. The high purity necessary for metallurgical and nuclear physics experiments led us to consider more elaborate purification processes, and a specially adapted method of fluoride preparation. The first part of the paper describes purification cycles of plutonium in solution on ion exchange resins, and the results are given. The second part contains the description and results of the fluoride preparation method. (author) [French] Dans le processus du traitement de l'uranium irradie, les cycles d'extraction au TBP permettent la separation du plutonium de la majorite des produits de fission et de l'uranium. La haute purete exigee pour les experiences de metallurgie et de physique nucleaire nous a conduit a envisager des purifications plus poussee et un mode de confection des fluorures specialement adapte. La premiere partie de l'expose decrit et donne les resultats de cycles de purification du plutonium en solution sur des resines echangeuses d'ions. La seconde partie decrit et donne les resultats du mode de confection des fluorures. (auteur)

Study by γ radiolysis and pulsed radiolysis of the reactivity of the superoxide ion in the oxyhemoglobin-methemoglobin system

International Nuclear Information System (INIS)

Haristoy, Didier.

1976-01-01

γ radiolysis of aqueous solutions of methemoglobin (MetHb) in the presence of formate ions, shows that only 25% of the total protein is reduced in oxyhemoglobin (HbO 2 ) by superoxide ions O 2 - according to the reaction MetHb+O 2 - →HbO 2 . The result can be attributed neither to the reactions of O 2 - with HbO 2 , nor the oxidation of HbO 2 by H 2 O 2 produced in the radiolysis of water and by dismutation of O 2 - . Pulse radiolysis studies of this reaction strongly suggest the formation of a transient complex 'MetHbO 2 - ' during the reaction. In addition to the well known self-oxidation of HbO 2 , these results show the existence of an equilibrium between HbO 2 and MetHb+O 2 - . Such an equilibrium could give rise, 'in vivo' to a nearly steady concentration of superoxide ions which could initiate a reaction favoring oxidation by oxygen [fr

Gamma-radiolysis of dimethyl sulfoxide. II. Radiolysis yields and possible mechanisms; Gamma-Radiolisis del dimetilsulfoxido II. Rendimientos radioloticos y posibles mecanismos

Energy Technology Data Exchange (ETDEWEB)

Gutierrez, M C; Barrera, R

1978-07-01

As result of quantitative studies on gamma-radiolysis of DMSO at a dose range of 90-850 Mrads, constant G values have been obtained for the following radiolysis compounds: G(-DMSO) - 6.7 {+-}0.2; G(dimethyl sulphide) - 3.4 {+-}0.3; G(methane) - 0,75 {+-} 0.04; G(dimethyl disulphide) -0.33 {+-}0,03; G(tri methylsulphonium methanesulphonate) - 0.26 {+-} 0,01; G(methyl methanethiosulphonate) - 0,25 {+-}0.02; G(dimethyl sulphona)-0.21{+-}0.02; G(H{sub 2})-0.18{+-}0.02; and G(propane)--0.0092{+-}0.0007. Initial G values have been obtained for other identified compounds: Gi(ethane)-0,46; Gi(CO)-0.052; and Gi(CO{sub 2})-0.030. Possible mechanisms on the radiolysis process are proposed. (Author) 17 refs.

The spectrographic analysis of plutonium oxide or mixed plutonium oxide/uranium oxide fuel pellets by the dried residue technique

International Nuclear Information System (INIS)

Jarbo, G.J.; Faught, P.; Hildebrandt, B.

1980-05-01

An emission spectrographic method for the quantitative determination of metallic impurities in plutonium oxide and mixed plutonium oxide/uranium oxide is described. The fuel is dissolved in nitric acid and the plutonium and/or uranium extracted with tributyl phosphate. A small aliquot of the aqueous residue is dried on a 'mini' pyrolitic graphite plate and excited by high voltage AC spark in an oxygen atmosphere. Spectra are recorded in a region which has been specially selected to record simultaneously lines of boron and cadmium in the 2nd order and all the other elements of interest in the 1st order. Indium is used as an internal standard. The excitation of very small quantities of the uraniumm/plutonium free residue by high voltage spark, together with three separate levels of containment reduce the hazards to personnel and the environment to a minimum with limited effect on sensitivity and accuracy of the results. (auth)

The radiolysis of CMPO: effects of acid, metal complexation and alpha vs. gamma radiation

International Nuclear Information System (INIS)

Mincher, B.J.; Groenewold, G.S.; Mezyk, S.P.

2016-01-01

The organophosphorus amide octyl(phenyl)-N,N-diisobutyl-carbamoylmethyl phosphine oxide (CMPO) is proposed for use in fuel cycle separations as a group actinide/lanthanide extractant. Alternative compounds such as the mono-amides and diglycol amides (DGAs) proposed for actinide and/or actinide/lanthanide extraction also contain the amidic functional group, but do not contain the CMPO aromatic or phosphoryl groups. Their radiation stability is in the order mono-amides > CMPO > DGA for irradiation under similar conditions. Although they produce similar radiolysis products, the kinetics of degradation for CMPO are completely different than for the other amides. CMPO degradation occurs in a zero-order fashion, and the -G-value for the change in [CMPO] is much lower when in the presence of acid. The DGAs and mono-amides degrade with pseudo-first-order kinetics and are not protected by acidity. Possible mechanistic reasons for the differences between CMPO and the other amides are discussed, as are the effects of the diluent and metal complexation on CMPO free radical reaction rates. Finally, it is also shown that α-irradiation has much less adverse effects on CMPO degradation than β/γ irradiation, both with respect to -G-values, and radiolysis product generation. (authors)

The radiolysis of CMPO: effects of acid, metal complexation and alpha vs. gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Mincher, B.J.; Groenewold, G.S. [Idaho National Laboratory, PO Box 1625, Idaho Falls, ID 83415 (United States); Mezyk, S.P. [California State University at Long Beach, Long Beach, CA 90840 (United States)

2016-07-01

The organophosphorus amide octyl(phenyl)-N,N-diisobutyl-carbamoylmethyl phosphine oxide (CMPO) is proposed for use in fuel cycle separations as a group actinide/lanthanide extractant. Alternative compounds such as the mono-amides and diglycol amides (DGAs) proposed for actinide and/or actinide/lanthanide extraction also contain the amidic functional group, but do not contain the CMPO aromatic or phosphoryl groups. Their radiation stability is in the order mono-amides > CMPO > DGA for irradiation under similar conditions. Although they produce similar radiolysis products, the kinetics of degradation for CMPO are completely different than for the other amides. CMPO degradation occurs in a zero-order fashion, and the -G-value for the change in [CMPO] is much lower when in the presence of acid. The DGAs and mono-amides degrade with pseudo-first-order kinetics and are not protected by acidity. Possible mechanistic reasons for the differences between CMPO and the other amides are discussed, as are the effects of the diluent and metal complexation on CMPO free radical reaction rates. Finally, it is also shown that α-irradiation has much less adverse effects on CMPO degradation than β/γ irradiation, both with respect to -G-values, and radiolysis product generation. (authors)

The uranium-plutonium breeder reactor fuel cycle

International Nuclear Information System (INIS)

Salmon, A.; Allardice, R.H.

1979-01-01

All power-producing systems have an associated fuel cycle covering the history of the fuel from its source to its eventual sink. Most, if not all, of the processes of extraction, preparation, generation, reprocessing, waste treatment and transportation are involved. With thermal nuclear reactors more than one fuel cycle is possible, however it is probable that the uranium-plutonium fuel cycle will become predominant; in this cycle the fuel is mined, usually enriched, fabricated, used and then reprocessed. The useful components of the fuel, the uranium and the plutonium, are then available for further use, the waste products are treated and disposed of safely. This particular thermal reactor fuel cycle is essential if the fast breeder reactor (FBR) using plutonium as its major fuel is to be used in a power-producing system, because it provides the necessary initial plutonium to get the system started. In this paper the authors only consider the FBR using plutonium as its major fuel, at present it is the type envisaged in all, current national plans for FBR power systems. The corresponding fuel cycle, the uranium-plutonium breeder reactor fuel cycle, is basically the same as the thermal reactor fuel cycle - the fuel is used and then reprocessed to separate the useful components from the waste products, the useful uranium and plutonium are used again and the waste disposed of safely. However the details of the cycle are significantly different from those of the thermal reactor cycle. (Auth.)

Simulation and control synthesis for a pulse column separation system for plutonium--uranium recovery

International Nuclear Information System (INIS)

McCutcheon, E.B.

1975-05-01

Control of a plutonium-uranium partitioning column was studied using a mathematical model developed to simulate the dynamic response and to test postulated separation mechanisms. The column is part of a plutonium recycle flowsheet developed for the recovery of plutonium and uranium from metallurgical scrap. In the first step of the process, decontamination from impurities is achieved by coextracting plutonium and uranium in their higher oxidation states. In the second step, reduction of the plutonium to a lower oxidation state allows partitioning of the plutonium and uranium. The use of hydroxylamine for the plutonium reduction in this partitioning column is a unique feature of the process. The extraction operations are carried out in pulse columns. (U.S.)

Radiolysis and radiosterilization of drugs

International Nuclear Information System (INIS)

Zeegers, F.; Crucq, A.S.; Gibella, M.; Tilquin, B.

1993-01-01

Can the absence of increased toxicological danger in irradiated foods be applied with confidence to drugs. The World Health Organization stated that up to 10 kGy there is no toxicological hazard. However, even if the irradiated drugs meet official standards, it would have to be established that any traces of radiolysis product formed are not toxic. All the tests from PHARMACOPEIA are not appropriate to detect the radiolysis and new physicochemical tests have to be used. Chromatographic detection of the radiosterilization of antibiotics may be advantageously used when the pharmaceuticals are not radio-resistant. The main obstacle to practical application is the low sensitivity of the detectors in liquid-liquid chromatography, a re-irradiation of the suspected samples will be necessary after preliminary chromatographic studies. 8 figs

Analysis of water radiolysis in relation to stress corrosion cracking of stainless steel at high temperatures - Effect of water radiolysis on limiting current densities of anodic and cathodic reactions under irradiation

International Nuclear Information System (INIS)

Ishigure, Kenkichi; Nukii, Takashi; Ono, Shoichi

2006-01-01

Electrochemical corrosion potential (ECP) is an important measure for environmental factor in relation to stress corrosion cracking (SCC) of metal materials. In the case of SCC for in-core materials in nuclear reactors, radiolysis of coolant water decisively controls ECP of metal materials under irradiation. In the previous models for ECP evaluation of stainless steel, radiolysis of reactor water in bulk was considered to calculate the bulk concentrations of the radiolysis products. In this work, the radiolysis not only in bulk but also in the diffusion layer at the interface between stainless steel and bulk water was taken into account in the evaluation of ECP. The calculation results shows that the radiolysis in the diffusion layer give significant effects on the limiting current densities of the redox reactions of the radiolysis products, H 2 O 2 and H 2 , depending on dose rate, flow rate and water chemistry, and leads to the significant increase in the ECP values in some cases, especially in hydrogen water chemistry conditions

Study of a plutonium substitute for the reducing back-extraction in low flow rate contactors; Etude d'un substitut du plutonium pour la desextraction reductrice dans des contacteurs a faible temps de sejour

Energy Technology Data Exchange (ETDEWEB)

Morell, M

1998-12-16

The aim of this work is to define and carry out a non-radioactive redox chemical system, similar to those of the plutonium, in a reducing back-extraction operation. In the first part, we have replaced our study within the context of the spent fuels. The choice of cerium as a plutonium substitute is justified and the used centrifugal drier described. The current process is presented and the set problem explained. The experimental study concerns essentially the research of reducers of the chosen substitute, the stability of ceric solutions, the measurement of distribution coefficients and the study of redox chemical kinetics. In the last part, are given the used simulation tools (development of a mathematical model in a first step and adaptation of the PAREX code in the second step) and the results of their comparison with the experimental data.

A rapid method of dosing plutonium in radioactive effluents; Methode de dosage rapide du plutonium dans les effluents radioactifs (1961)

Energy Technology Data Exchange (ETDEWEB)

Scheidhauer, J; Messainguiral, L [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

1961-07-01

The plutonium is first separated by a lanthanum fluoride precipitation. The precipitated fluorides are dissolved in normal nitric acid solution in the presence of aluminium nitrate. The plutonium transformed to the tetravalent state is then extracted with thenoyltrifluoroacetone and returned to the aqueous phase with 10 N nitric acid. After evaporation on a watch glass the residue is calcined on a Meker burner and counted using a counting system fitted with a zinc sulphide scintillator. When necessary, the calcium is eliminated at the beginning of the dosage by a fluoride precipitation, the plutonium being oxidised to the valency IV. (authors) [French] Le plutonium est d'abord separe par entrainement au fluorure de lanthane. Le precipite des fluorures est remis en solution en milieu acide nitrique normal, en presence de nitrate d'aluminium. Le plutonium amene a la valence IV est alors extrait par la thenoyltrifluoroacetone et remis en phase aqueuse dans l'acide nitrique 10 N. Apres evaporation sur verre de montre, le residu est calcine sur bec Meker et compte sur un ensemble de comptage equipe d'un scintillateur au sulfure de zinc. Lorsque cela est necessaire, le calcium est elimine, au debut du dosage, par precipitation du fluorure, le plutonium etant oxyde a la valence VI. (auteurs)

Plutonium separation by reduction stripping. Application to processing of mixed oxide (U,Pu)O2 fuel fabrication wastes

International Nuclear Information System (INIS)

Arnal, Thierry; Cousinou, Gerard; Ganivet, Michel.

1978-11-01

A procedure is described for separating plutonium from a uranium VI and plutonium IV mixture contained in an organic phase (tributyl phosphate diluted in dodecane). This separation is obtained by extracting the plutonium III using two organic reducers: hydrazine and paraminophenol. Paraminophenol has excellent reducing qualities, similar to those of ferrous sulphamate, but has the added advantage of not contaminating extracted plutonium. This procedure is currently used in processing production wastes from mixed oxide (U,Pu)O 2 fuels; the installation using this procedure is described in detail in this paper. Operating results show the remarkable efficiency of this procedure: the separated plutonium and uranium mass flows have been increased to 185 and 350 g.h -1 respectively; the uranium contains less than 0.1 ppm of plutonium on completion of the purification cycle [fr

Plutonium

International Nuclear Information System (INIS)

Watson, G.M.

1976-01-01

Discovery of the neutron made it easy to create elements which do not exist in nature. One of these is plutonium, and its isotope with mass number 239 has nuclear properties which make it both a good fuel for nuclear power reactors and a good explosive for nuclear weapons. Since it was discovered during a war the latter characteristic was put to use, but it is now evident that use of plutonium in a particular kind of nuclear reactor, the fast breeder reactor, will allow the world's resources of uranium to last for millennia as a major source of energy. Plutonium is very radiotoxic, resembling radium in this respect. Therefore the widespread introduction of fast breeder reactors to meet energy demands can be contemplated only after assurances on two points; that adequate control of the radiological hazard resulting from the handling of very large amounts of plutonium can be guaranteed, and that diversion of plutonium to illicit use can be prevented. The problems exist to a lesser degree already, since all types of nuclear reactor produce some plutonium. Some plutonium has already been dispersed in the environment, the bulk of it from atmospheric tests of nuclear weapons. (author)

The first milligrams of plutonium

International Nuclear Information System (INIS)

Goldschmidt, B.

1997-01-01

A historical review of the development of the very first quantities of plutonium produced during World War II in the United States and in Canada, as remembered by the French nuclear chemist, Mr Goldschmidt, who participated to the various programs which were involved in the development of the atomic bomb, and to the first steps of the French atomic program after the war. Mr Goldschmidt worked especially on organic solvent extraction, with the selection, in 1945, of non volatile tri glycol dichloride, and the development of the Chalk River plant. In 1949, at the Bouchet plant, his team has isolated the first milligrams of French plutonium from uranium oxide; and in 1952, the PUREX process was developed

The radiolysis of CMPO: effects of acid, metal complexation and alpha vs. gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Bruce J. Mincher; Stephen P. Mezyk; Gary S. Groenewold

2016-05-01

Abstract The group actinide/lanthanide complexing agent octylphenylcarbamoylmethyl phosphine oxide (CMPO) has been examined for its radiation stability by measuring the kinetics of its reactions with free radicals in both the aqueous and organic phases for the free and metal-complexed ligand, identifying its degradation products for both alpha and gamma irradiation, measuring the effects on solvent extraction performance, and measuring the G-values for its degradation under various conditions. This includes the G-values for CMPO in the absence of, and in contact with the acidic aqueous phase, where it is shown that the acidic aqueous phase provides radio-protection for this ligand. It was found that both solvent and metal complexation affect the kinetics of the reaction of the •NO3 radical, a product of HNO3 radiolysis, with CMPO. For example, CMPO complexed with lanthanides has a rate constant for this reaction an order of magnitude higher than for the free ligand, and the reaction for the free ligand in the organic phase is about three times faster than in the aqueous phase. In steady state radiolysis kinetics it was determined that HNO3, although not NO3- anion, provides radio-protection to CMPO, with the G-value for its degradation decreasing with increasing acidity, until it was almost completely suppressed by irradiation in contact with 5 M HNO3. The same degradation products were produced by irradiation with alpha and gamma-sources, except that the relative abundances of these products varied. For example, the product of C-C bond scission was produced only in low amounts for gamma-radiolysis, but it was an important product for samples irradiated with a He ion beam. These results are compared to the new data appearing in the literature on DGA radiolysis, since CMPO and the DGAs both contain the amide functional group.

Formation of carbonyl compounds in radiolysis of ethylene glycol in methanol

International Nuclear Information System (INIS)

Bezborodova, S.G.; Vetrov, V.S.; Kalyazin, E.P.; Korolev, V.M.; Salamatov, I.I.

1977-01-01

Radiolysis of diluted solutions of ethylene glycol has been investigated. It is shown that acetaldehyde, glycol aldehyde and formaldehyde are the main products of radiolysis of methanol solutions of ethylene glycol. Acetaldehyde and glycol aldehyde yields increase in radiolysis of methanol solutions of ethylene glycol with an increase of the original concentration of ethylene glycol and a temperature rise of radiolysis. Formaldehyde yields increase with the ethylene glycol concentration but decrease with a temperature rise (the formation of formaldehyde from methanol is taken into account). A mechanism of radiation-chemical transformations of ethylene glycol in methanol is explained. It is concluded that the main directions of ethylene glycol decomposition, detected in water solutions of ethylene glycol, are also realized in methanol solutions. However, a role of different directions of decomposition depends on the medium

Radiolysis of groundwater in a repository for spent fuel - a literature survey

International Nuclear Information System (INIS)

Snellman, Margit

1989-06-01

This review on radiolysis considers both the fundamental mechanisms and theory involved in radiolysis of pure water and systems containing major species existing in repository conditions. The amount of different molecules and radicals formed in radiolysis of water is a complex function of the type of radiation and dose rate, pH and ionic strength of water. The principal effects of the species present in water are to scavenge the radiolytic intermediates and products producing new species and changing the yield of radical and molecular products. Of the metals (Cu, Fe) and inorganic ions (Cl - , HCO 3 - /CO 3 2- , NH 3 /NO 2 - ) considered, iron is the most important one and can participate in a number of reactions both with the primary and secondary radiolysis products and may effect both the H 2 and H 2 O 2 yield. For the estimation of the overall effect of radiolysis in the repository both calculations and supporting experimental work is needed

Structural analysis of radiolysis products of sennoside

International Nuclear Information System (INIS)

Song, Hyun Pa; Kim, Dong Ho

2011-01-01

The purpose of the present investigation was to analyze the structural changes of gamma irradiated sennoside B (prodrug) and to provide the possibility for application of irradiation to induce structural changes of the prodrugs for enhanced bioavailability. Sennoside B (200 ppm) in 70% methanol solution with or without the use of hydrogen peroxide or nitrous oxide gas was irradiated with 1, 3, 5, 10 and 20 kGy by gamma ray. The radiolysis products of gamma irradiated sennoside B solution were identified and determined by TLC, HPLC and LC-MS/MS. The sennoside B quantity decreased when irradiation dose increased and completely degraded at 10 kGy of irradiation. There was a linear relationship between the production of the radiolysis compounds and the absorbed dose of the gamma ray irradiated sennoside B. Radiolysis products yields increased on the addition of nitrous oxide gas into the sennoside B solution. No anthraquinone compounds were formed after irradiation of sennosie B. Scission of the O-glycoside bond and consequently formation of aglycone of sennoside B was observed

Structural analysis of radiolysis products of sennoside

Energy Technology Data Exchange (ETDEWEB)

Song, Hyun Pa; Kim, Dong Ho [KAERI, Daejeon (Korea, Republic of)

2011-01-15

The purpose of the present investigation was to analyze the structural changes of gamma irradiated sennoside B (prodrug) and to provide the possibility for application of irradiation to induce structural changes of the prodrugs for enhanced bioavailability. Sennoside B (200 ppm) in 70% methanol solution with or without the use of hydrogen peroxide or nitrous oxide gas was irradiated with 1, 3, 5, 10 and 20 kGy by gamma ray. The radiolysis products of gamma irradiated sennoside B solution were identified and determined by TLC, HPLC and LC-MS/MS. The sennoside B quantity decreased when irradiation dose increased and completely degraded at 10 kGy of irradiation. There was a linear relationship between the production of the radiolysis compounds and the absorbed dose of the gamma ray irradiated sennoside B. Radiolysis products yields increased on the addition of nitrous oxide gas into the sennoside B solution. No anthraquinone compounds were formed after irradiation of sennosie B. Scission of the O-glycoside bond and consequently formation of aglycone of sennoside B was observed

Radiolytic and thermal stability of selected plutonium salts containing nitrate groups

International Nuclear Information System (INIS)

Bryan, G.H.

1976-04-01

(Pu(NO 3 ) 4 . XH 2 O, K 2 Pu(NO 3 ) 6 , and (NH 4 ) 2 Pu(NO 3 ) 6 ) were studied to evaluate their ability to serve as shipping forms that meet criteria. The radiolytic gas evolution study eliminated (NH 4 ) 2 Pu(NO 3 ) 6 from further consideration. None of the compounds produced H 2 or O 2 in sufficient quantity to produce a flammable mixture, except Pu(NO 3 ) 4 . XH 2 O which produced O 2 and H 2 in a ratio that is above explosive limits after long storage time. The ammonium salt decomposition appears to be about the same as that observed upon heating of NH 4 NO 3 to produce N 2 , H 2 O, and nitrous oxides. Plutonium nitrate contains hydration water. This water is of some concern due to the production of hydrogen by alpha-radiolysis. Two waters of hydration appear to be the lower limit to which Pu(NO 3 ) 4 . XH 2 O may be taken before decomposition of the solid begins. TGA results indicate the simple nitrate (Pu(NO 3 ) 4 . XH 2 O) is somewhat less thermally stable than either the ammonium or potassium hexanitrato plutonate which detracts somewhat from its suitability as a shipping form. Maintaining large quantities of this compound with a high 238 Pu content (less than 1 percent 238 Pu) may require specially designed and larger containers to prevent thermal degradation and gas pressure buildup problems. The informaion was presented to plutonium processors; the final consensus of this group was that in spite of some thermal instability of Pu(NO 3 ) 4 . XH 2 O at fairly low temperatures, it was preferable to K 2 Pu(NO 3 ) 6 due to the additional waste disposal problems the potassium would present. (Pu(NO 3 ) 4 . XH 2 O also has several other advantages. A possible problem that could arise due to the variable weight of plutonium nitrate could be in plutonium accountability, but this would be prevented if the plutonium content of the solution prior to evaporation to the solid is known

Plutonium Finishing Plant. Interim plutonium stabilization engineering study

Energy Technology Data Exchange (ETDEWEB)

Sevigny, G.J.; Gallucci, R.H.; Garrett, S.M.K.; Geeting, J.G.H.; Goheen, R.S.; Molton, P.M.; Templeton, K.J.; Villegas, A.J. [Pacific Northwest Lab., Richland, WA (United States); Nass, R. [Nuclear Fuel Services, Inc. (United States)

1995-08-01

This report provides the results of an engineering study that evaluated the available technologies for stabilizing the plutonium stored at the Plutonium Finishing Plant located at the hanford Site in southeastern Washington. Further processing of the plutonium may be required to prepare the plutonium for interim (<50 years) storage. Specifically this document provides the current plutonium inventory and characterization, the initial screening process, and the process descriptions and flowsheets of the technologies that passed the initial screening. The conclusions and recommendations also are provided. The information contained in this report will be used to assist in the preparation of the environmental impact statement and to help decision makers determine which is the preferred technology to process the plutonium for interim storage.

Plutonium Finishing Plant. Interim plutonium stabilization engineering study

International Nuclear Information System (INIS)

Sevigny, G.J.; Gallucci, R.H.; Garrett, S.M.K.; Geeting, J.G.H.; Goheen, R.S.; Molton, P.M.; Templeton, K.J.; Villegas, A.J.; Nass, R.

1995-08-01

This report provides the results of an engineering study that evaluated the available technologies for stabilizing the plutonium stored at the Plutonium Finishing Plant located at the hanford Site in southeastern Washington. Further processing of the plutonium may be required to prepare the plutonium for interim (<50 years) storage. Specifically this document provides the current plutonium inventory and characterization, the initial screening process, and the process descriptions and flowsheets of the technologies that passed the initial screening. The conclusions and recommendations also are provided. The information contained in this report will be used to assist in the preparation of the environmental impact statement and to help decision makers determine which is the preferred technology to process the plutonium for interim storage

Surveillance and Maintenance Plan for the Plutonium Uranium Extraction (PUREX) Facility

International Nuclear Information System (INIS)

Woods, P.J.

1998-05-01

This document provides a plan for implementing surveillance and maintenance (S ampersand M) activities to ensure the Plutonium Uranium Extraction (PUREX) Facility is maintained in a safe, environmentally secure, and cost-effective manner until subsequent closure during the final disposition phase of decommissioning. This plan has been prepared in accordance with the guidelines provided in the U.S. Department of Energy (DOE), Office of Environmental Management (EM) Decommissioning Resource Manual (DOE/EM-0246) (DOE 1995), and Section 8.6 of TPA change form P-08-97-01 to the Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement) (Ecology, et al. 1996). Specific objectives of the S ampersand M program are: Ensure adequate containment of remaining radioactive and hazardous material. Provide security control for access into the facility and physical safety to surveillance personnel. Maintain the facility in a manner that will minimize potential hazards to the public, the environment, and surveillance personnel. Provide a plan for the identification and compliance with applicable environmental, safety, health, safeguards, and security requirements

Stop plutonium

International Nuclear Information System (INIS)

2003-02-01

This press document aims to inform the public on the hazards bound to the plutonium exploitation in France and especially the plutonium transport. The first part is a technical presentation of the plutonium and the MOX (Mixed Oxide Fuel). The second part presents the installation of the plutonium industry in France. The third part is devoted to the plutonium convoys safety. The highlight is done on the problem of the leak of ''secret'' of such transports. (A.L.B.)

Pulse radiolysis

International Nuclear Information System (INIS)

Greenshields, H.; Seddon, W.A.

1982-03-01

This supplement to two bibliographies published in 1970 and 1972 lists 734 references to the literature of pulse radiolysis, arranged under eight broad subject headings. The references were compiled by searching Biological Abstracts, Chemical Abstracts, Nuclear Science Abstracts and the Weekly List of Papers in Radiation Chemistry issued by the Radiation Chemistry Data Center of Notre Dame University. Full bibliographic data is given for papers published in the period 1971 to 1974. A personal author index listing more than 600 authors and a similar number of co-authors is included

Study of a plutonium substitute for the reducing back-extraction in low flow rate contactors; Etude d'un substitut du plutonium pour la desextraction reductrice dans des contacteurs a faible temps de sejour

Energy Technology Data Exchange (ETDEWEB)

Morell, M

1998-12-16

The aim of this work is to define and carry out a non-radioactive redox chemical system, similar to those of the plutonium, in a reducing back-extraction operation. In the first part, we have replaced our study within the context of the spent fuels. The choice of cerium as a plutonium substitute is justified and the used centrifugal drier described. The current process is presented and the set problem explained. The experimental study concerns essentially the research of reducers of the chosen substitute, the stability of ceric solutions, the measurement of distribution coefficients and the study of redox chemical kinetics. In the last part, are given the used simulation tools (development of a mathematical model in a first step and adaptation of the PAREX code in the second step) and the results of their comparison with the experimental data.

Comparison of extraction chromatography and a procedure based on the molecular recognition method as separation methods in the determination of neptunium and plutonium radionuclides

International Nuclear Information System (INIS)

Strisovska, Jana; Galanda, Dusan; Drabova, Veronika; Kuruc, Jozef

2012-01-01

The potential of various types of sorbents for separation of radionuclides of plutonium and neptunium were examined. Extraction chromatography and a procedure based on the molecular recognition method were used for the separation. The suitability of the various sorbent types and brands for this purpose was determined. (orig.)

A computerized pulse radiolysis system

International Nuclear Information System (INIS)

Eriksen, T.E.; Lind, J.; Reitberger, T.

1976-01-01

A computer based pulse radiolysis system for gathering and handling of transient optical absorption and electric conductivity data is presented. The system has been developed around a Biomation 8100 transient recorder and a PDP 11/40 (Digital Equipment Corp) computer. (author)

A method for the separation of sodium and iron from plutonium and other impurities in concentrated plutonium solution and their subsequent measurement

International Nuclear Information System (INIS)

Mair, M.A.; Brown, M.L.

1988-06-01

Sodium and iron are separated from plutonium and other impurities by solvent extraction. Sodium is determined by flame photometry and iron by spectrophotometric measurement of the orthophenanthroline complex. (author)

Radiation chemistry

Energy Technology Data Exchange (ETDEWEB)

None

1973-07-01

Research progress is reported on radiation chemistry of heavy elements that includes the following topics: radiation chemistry of plutonium in nitric acid solutions (spectrophotometric analysis and gamma radiolysis of Pu(IV) and Pu(VI) in nitric acid solution); EPR studies of intermediates formed in radiolytic reactions with aqueous medium; two-phase radiolysis and its effect on the distribution coefficient of plutonium; and radiation chemistry of nitric acid. (DHM)

Radiolysis of starch

International Nuclear Information System (INIS)

Raffi, J.; Saint-Lebe, L.; Berger, G.

1978-01-01

In the first part of the paper the results of work on the identification and determination of the gamma ( 60 Co) radiolysis products of maize starch are brought together and, wherever possible, a balance drawn up by chemical class. The second part of the paper deals with the main parameters governing radiolysis: dose, irradiation temperature and atmosphere, water content and the conditions under which the irradiated starch is stored. The third part, devoted to the mechanisms believed to be involved, contains the following conclusions: (a) the formation of radiation-induced products with a carbon skeleton probably results from a breaking of the -C-O-C- chains with rearrangement of the radicals and/or a reaction involving the water and the oxygen - the oxygen has an activating effect which does not fundamentally modify the mechanism, whereas the effect of the water is more complex and varies according to the product; (b) the formation of hydrogen peroxide probably implies the addition of atmospheric oxygen to the radiation-induced hydrogen atoms in the water or to the organic radicals obtained by abstraction of a hydrogen from the starch. Lastly, the different methods envisaged for confirming or improving the mechanistic hypotheses are discussed. (author)

Separation Techniques for Uranium and Plutonium at Trace Levels for the Thermal Ionization Mass Spectrometric Determination

International Nuclear Information System (INIS)

Suh, M. Y.; Han, S. H.; Kim, J. G.; Park, Y. J.; Kim, W. H.

2005-12-01

This report describes the state of the art and the progress of the chemical separation and purification techniques required for the thermal ionization mass spectrometric determination of uranium and plutonium in environmental samples at trace or ultratrace levels. Various techniques, such as precipitation, solvent extraction, extraction chromatography, and ion exchange chromatography, for separation of uranium and plutonium were evaluated. Sample preparation methods and dissolution techniques for environmental samples were also discussed. Especially, both extraction chromatographic and anion exchange chromatographic procedures for uranium and plutonium in environmental samples, such as soil, sediment, plant, seawater, urine, and bone ash were reviewed in detail in order to propose some suitable methods for the separation and purification of uranium and plutonium from the safeguards environmental or swipe samples. A survey of the IAEA strengthened safeguards system, the clean room facility of IAEA's NWAL(Network of Analytical Laboratories), and the analytical techniques for safeguards environmental samples was also discussed here

Separation Techniques for Uranium and Plutonium at Trace Levels for the Thermal Ionization Mass Spectrometric Determination

Energy Technology Data Exchange (ETDEWEB)

Suh, M. Y.; Han, S. H.; Kim, J. G.; Park, Y. J.; Kim, W. H

2005-12-15

This report describes the state of the art and the progress of the chemical separation and purification techniques required for the thermal ionization mass spectrometric determination of uranium and plutonium in environmental samples at trace or ultratrace levels. Various techniques, such as precipitation, solvent extraction, extraction chromatography, and ion exchange chromatography, for separation of uranium and plutonium were evaluated. Sample preparation methods and dissolution techniques for environmental samples were also discussed. Especially, both extraction chromatographic and anion exchange chromatographic procedures for uranium and plutonium in environmental samples, such as soil, sediment, plant, seawater, urine, and bone ash were reviewed in detail in order to propose some suitable methods for the separation and purification of uranium and plutonium from the safeguards environmental or swipe samples. A survey of the IAEA strengthened safeguards system, the clean room facility of IAEA's NWAL(Network of Analytical Laboratories), and the analytical techniques for safeguards environmental samples was also discussed here.

Radiolysis of concentrated nitric acid solutions

International Nuclear Information System (INIS)

Nagaishi, R.; Jiang, P.Y.; Katsumura, Y.; Domae, M.; Ishigure, K.

1995-01-01

A study on electron pulse- and 60 Co γ-radiolysis of concentrated nitric acid and nitrate solutions has been carried out to elucidate the radiation induced reactions taking place in the solutions. Dissociation into NO 2 - and O( 3 P) was proposed as a direct action of the radiation on nitrate and gave the G-values were dependent on the chemical forms of nitrate: g s2 (-NO 3 - )=1.6 and g s2 (-HNO 3 )=2.2 (molecules/100eV). Based on the experimental yields of HNO 2 and reduced Ce IV , the primary yields of radiolysis products of water, g w , were evaluated to clarify the effects of nitrate on spur reactions of water in various nitrate solutions. (author)

Adsorption and diffusion of plutonium in soil

International Nuclear Information System (INIS)

Relyea, J.F.; Brown, D.A.

1978-01-01

The behavior of plutonium in soil--water systems was studied by measuring its apparent diffusion coefficient in the aqueous and solid phases and by finding the adsorption--desorption relationships between soil and solution. Apparent diffusion coefficients of plutonium in soil were measured using a quick-freeze method. Aqueous diffusion was studied in a capillary-tube diffusion cell. Adsorption studies were done by equilibrating a tagged soil--water mixture on a rotary shaker before centrifuging and sampling. As expected from high adsorption coefficients (Kd) (300--10,000), the apparent diffusion coefficients were low compared with normal soil cations (1.4 x 10 -8 cm 2 /sec in a sandy soil to less than 2.4 x 10 -11 cm 2 /sec in a silt loam). The Kd of plutonium in aqueous solution containing the chelate ethylenediaminetetraacetic acid (EDTA) was reduced compared with the Kd in dilute HNO 3 . As the EDTA concentration was increased, the Kd was decreased. The chelate diethylenetriaminepentaacetic acid (DTPA) reduced the Kd more than EDTA at comparable concentrations. The aqueous diffusion coefficients varied from 3.1 x 10 -7 cm 2 /sec in a solution extracted from the silt loam up to 2.7 x 10 -5 cm 2 /sec in a solution extracted from the sandy soil

The plutonium challenge for the future

International Nuclear Information System (INIS)

Gray, L.W.

2000-01-01

, followed by dissolution utilizing an Ag(II)-nitric acid method. The plutonium would be purified by one cycle of solvent extraction, precipitated as plutonium oxalate and then converted to oxide. This would not only remove the gallium but would provide the correct morphology for preparation of the MOX fuel. The Immobilization program in the United States would mineralize the plutonium contained in a variety of residues that were left in place when the weapons production complex was shut-down at the end of the cold war. These residues have a wide range of impurity contents, typically from a few parts per million to > 90 wt. %. Plutonium in these residues would be blended to level the impurities and thereby avoid reprocessing of this plutonium. This blended plutonium would then be mineralized at high temperature in a titanate ceramic followed by canning of the ceramic pucks. These cans would by loaded into a magazine and then locked into place within a stainless steel canister. The plutonium ceramic would then be encased in high level waste glass. A high radiation field would protect the plutonium in the spent MOX fuel and the immobilized ceramic form for some period of time. Within the time period of the high radiation field, these forms would be entombed in an underground repository. This, however, disposes of only 50 tonnes of the approximately 1700 tonnes of the worldwide weapons- usable plutonium. Russia will dispose of another 50 tonnes via the MOX burning route. Worldwide approximately 1600 tonnes of weapons-usable plutonium is still available either as spent fuel or as separate plutonium oxide. Is society prepared to deal with these 1600 tonnes of plutonium? At the present growth rate, before the United States and Russia completes the disposition of the 100 tonnes of weapons-grade plutonium, the worldwide stockpile will exceed 2000 tonnes. (author)

Determination by gamma-ray spectrometry of the plutonium and americium content of the Pu/Am separation scraps. Application to molten salts; Determination par spectrometrie gamma de la teneur en plutonium et en americium de produits issus de separation Pu/Am. Application aux bains de sels

Energy Technology Data Exchange (ETDEWEB)

Godot, A. [CEA Valduc, Dept. de Traitement des Materiaux Nucleaires, 21 - Is-sur-Tille (France); Perot, B. [CEA Cadarache, Dept. de Technologie Nucleaire, Service de Modelisation des Transferts et Mesures Nucleaires, 13 - Saint-Paul-lez-Durance (France)

2005-07-01

Within the framework of plutonium recycling operations in CEA Valduc (France), americium is extracted from molten plutonium metal into a molten salt during an electrolysis process. The scraps (spent salt, cathode, and crucible) contain extracted americium and a part of plutonium. Nuclear material management requires a very accurate determination of the plutonium content. Gamma-ray spectroscopy is performed on Molten Salt Extraction (MSE) scraps located inside the glove box, in order to assess the plutonium and americium contents. The measurement accuracy is influenced by the device geometry, nuclear instrumentation, screens located between the sample and the detector, counting statistics and matrix attenuation, self-absorption within the spent salt being very important. The purpose of this study is to validate the 'infinite energy extrapolation' method employed to correct for self-attenuation, and to detect any potential bias. We present a numerical study performed with the MCNP computer code to identify the most influential parameters and some suggestions to improve the measurement accuracy. A final uncertainty of approximately 40% is achieved on the plutonium mass. (authors)

Identification and evaluation of radiolysis products of irradiated chloramphenicol by HPLC-MS and HPLC-DAD

Energy Technology Data Exchange (ETDEWEB)

Hong, L; Altorfer, H R [Institute of Pharmaceutical Science, Swiss Federal Institute of Technology (ETH), Zurich (Switzerland); Horni, A; Hesse, M [Institute of Organic Chemistry, University of Zurich, Zurich (Switzerland)

2005-07-01

The radiolysis products of chloramphenicol under {gamma}-radiation sterilization were investigated systematically in the present study. Eight main radiolysis products were identified and quantified by HPLC-MS and HPLC-DAD, including two compounds that have never been reported. The minor radiolysis products were quantified, which shows that they are at the concentration levels below the threshold for identification. Carbon-carbon rupture reaction and oxidation reaction were proposed as the main radiolysis reactions of chloramphenicol powder. The applicability of {gamma}-sterilization for chloramphenicol products was quantitatively evaluated with qualitative and quantitative data and the data were compared to the threshold requirements of international regulations for identification. It was concluded that toxicities of the radiolysis products of chloramphenicol produced by {gamma}-radiation sterilization can be neglected, the radiolysis products are safe for human health from chemical view. (author)

Identification and evaluation of radiolysis products of irradiated chloramphenicol by HPLC-MS and HPLC-DAD

International Nuclear Information System (INIS)

Hong, L.; Altorfer, H.R.; Horni, A.; Hesse, M.

2005-01-01

The radiolysis products of chloramphenicol under γ-radiation sterilization were investigated systematically in the present study. Eight main radiolysis products were identified and quantified by HPLC-MS and HPLC-DAD, including two compounds that have never been reported. The minor radiolysis products were quantified, which shows that they are at the concentration levels below the threshold for identification. Carbon-carbon rupture reaction and oxidation reaction were proposed as the main radiolysis reactions of chloramphenicol powder. The applicability of γ-sterilization for chloramphenicol products was quantitatively evaluated with qualitative and quantitative data and the data were compared to the threshold requirements of international regulations for identification. It was concluded that toxicities of the radiolysis products of chloramphenicol produced by γ-radiation sterilization can be neglected, the radiolysis products are safe for human health from chemical view. (author)

Aqueous recovery of plutonium from pyrochemical processing residues

International Nuclear Information System (INIS)

Gray, L.W.; Gray, J.H.

1984-01-01

Pyrochemical processes provide rapid methods to reclaim plutonium from scrap residues. Frequently, however, these processes yield an impure plutonium product and waste residues that are contaminated with actinides and are therefore nondiscardable. The Savannah River Laboratory and Plant and the Rocky Flats Plant are jointly developing new processes using both pyrochemistry and aqueous chemistry to generate pure product and discardable waste. An example of residue being treated is that from the molten salt extraction (MSE), a mixture of NaCl, KCl, MgCl 2 , PuCl 3 , AmCl 3 , PuO 2 , and Pu 0 . This mixture is scrubbed with molten aluminum containing a small amount of magnesium to produce a nonhomogeneous Al-Pu-Am-Mg alloy. This process, which rejects most of the NaCl-KCl-MgCl 2 salts, results in a product easily dissolved in 6M HNO 3 -0.1M HF. Any residual chloride in the product is removed by precipitation with Hg(I) followed by centrifuging. Plutonium and americium are then separated by the standard Purex process. The americium, initially diverted to the solvent extraction waste stream, can either be recovered or sent to waste

Spectrophotometric determination of plutonium with chlorophosphonazo III in n-pentanol

International Nuclear Information System (INIS)

Saponara, N.M.; Marsh, S.F.

1982-03-01

Microgram amounts of plutonium are measured spectrophotometrically as the plutonium-chlorophosphonazo III complex after extraction into n-pentanol from 1.5 M HCl. The relative standard deviation is 1.5% for the range of 2.5 to 17.5 μg. The tolerance is excellent for many metals and nonmetals present in nuclear fuel-cycle materials. A preceding anion-exchange-column separation increases tolerance for certain metals and nonmetals

Recommended plutonium release fractions from postulated fires. Final report

International Nuclear Information System (INIS)

Kogan, V.; Schumacher, P.M.

1993-12-01

This report was written at the request of EG ampersand G Rocky Flats, Inc. in support of joint emergency planning for the Rocky Flats Plant (RFP) by EG ampersand G and the State of Colorado. The intent of the report is to provide the State of Colorado with an independent assessment of any respirable plutonium releases that might occur in the event of a severe fire at the plant. Fire releases of plutonium are of interest because they have been used by EG ampersand G to determine the RFP emergency planning zones. These zones are based on the maximum credible accident (MCA) described in the RFP Final Environmental Impact Statement (FEIS) of 1980, that MCA is assumed to be a large airplane crashing into a RFP plutonium building.The objective of this report was first, to perform a worldwide literature review of relevant release experiments from 1960 to the present and to summarize those findings, and second, to provide recommendations for application of the experimental data to fire release analyses at Rocky Flats. The latter step requires translation between experimental and expected RFP accident parameters, or ''scaling.'' The parameters of particular concern are: quantities of material, environmental parameters such as the intensity of a fire, and the physico-chemical forms of the plutonium. The latter include plutonium metal, bulk plutonium oxide powder, combustible and noncombustible wastes contaminated with plutonium oxide powder, and residues from plutonium extraction processes

Determination of plutonium in pure plutonium nitrate solutions - Gravimetric method

International Nuclear Information System (INIS)

1987-01-01

This International Standard specifies a precise and accurate gravimetric method for determining the concentration of plutonium in pure plutonium nitrate solutions and reference solutions, containing between 100 and 300 g of plutonium per litre, in a nitric acid medium. The weighed portion of the plutonium nitrate is treated with sulfuric acid and evaporated to dryness. The plutonium sulfate is decomposed and formed to oxide by heating in air. The oxide is ignited in air at 1200 to 1250 deg. C and weighed as stoichiometric plutonium dioxide, which is stable and non-hygroscopic

Chemical evolution studies: the radiolysis and thermal decomposition of malonic acid

International Nuclear Information System (INIS)

Cruz-Castaneda, J.; Negron-Mendoza, A.; Heredia, A.; Ramos-Bernal, S.; Villafane-Barajas, S.; Frias, D.; Colin-Garcia, M.

2015-01-01

In the context of chemical evolution a simulation of a hydrothermal vent was performed. The thermolysis and radiolysis of malonic acid in aqueous solution were studied. The thermolysis was done by heating the samples (95 deg C) and radiolysis using gamma radiation. Products were identified by gas chromatography and gas chromatography-mass spectrometry. The thermal treatment produced acetic acid and CO 2 . The radiolysis experiments yield carbon dioxide, acetic acid, and di- and tricarboxylic acids. A theoretical model of the chemical process occurring under irradiation was developed; this was able to reproduce formation of products and the consumption of malonic acid. (author)

Radiolysis and corrosion aspects of the aqueous self-cooled blanket concept

International Nuclear Information System (INIS)

Bruggeman, A.; Snykers, M.; Bogaerts, W.F.; Waeben, R.; Embrechts, M.J.; Steiner, D.

1989-01-01

Corrosion and radiolysis aspects of the Aqueous Self-Cooled Blanket concept, proposed as a potential shielding breeding blanket for near term fusion devices and fusion reactors, have been investigated. On the basis of preliminary results for selected aqueous solutions of lithium compounds, no particular corrosion problems have been revealed for the low-temperature concept envisaged for NET and radiolysis effects might be controlled by appropriate countermeasures. For the reactor-relevant high-temperature concept particular attention has to be paid to intergranular stress-corrosion and to the synergistic radiolysis-corrosion effects. Further information is needed from tests performed in relevant operational conditions. (orig.)

Determination of oxidation products in radiolysis of halophenols with pulse radiolysis, hplc, and ion chromatography

International Nuclear Information System (INIS)

Ye, M.; Schuler, R.H.

1990-01-01

This paper reports on hydroxyl radicals that react with halogen substituted phenols by several different ways. One is addition of OH radicals to the aromatic ring, which is followed by elimination of hydrogen halide, H 2 O or H - . The positions of OH radicals attack are dependent on the nature of the halogen which affects the electronic distribution in the ring. The oxidation of fluorophenols, chlorophenols and bromophenols with hydroxyl radicals in N 2 O saturated solution has been investigated with pulse radiolysis and γ-irradiation experiments. The intermediates of the reactions were studied by pulse radiolysis. The products created in the γ-irradiation of aqueous solutions of halophenols were analyzed by ion chromatography and high performance liquid chromatography (HPLC). With the combination of time-resolved and steady-state experiments a complete and detailed description of radiolytic oxidation of halophenols by hydroxyl radicals was obtained

Precipitation of plutonium (III) oxalate and calcination to plutonium oxide

International Nuclear Information System (INIS)

Esteban, A.; Orosco, E.H.; Cassaniti, P.; Greco, L.; Adelfang, P.

1989-01-01

The plutonium based fuel fabrication requires the conversion of the plutonium nitrate solution from nuclear fuel reprocessing into pure PuO2. The conversion method based on the precipitation of plutonium (III) oxalate and subsequent calcination has been studied in detail. In this procedure, plutonium (III) oxalate is precipitated, at room temperature, by the slow addition of 1M oxalic acid to the feed solution, containing from 5-100 g/l of plutonium in 1M nitric acid. Before precipitation, the plutonium is adjusted to trivalent state by addition of 1M ascorbic acid in the presence of an oxidation inhibitor such as hydrazine. Finally, the precipitate is calcinated at 700 deg C to obtain PuO2. A flowsheet is proposed in this paper including: a) A study about the conditions to adjust the plutonium valence. b) Solubility data of plutonium (III) oxalate and measurements of plutonium losses to the filtrate and wash solution. c) Characterization of the obtained products. Plutonium (III) oxalate has several potential advantages over similar conversion processes. These include: 1) Formation of small particle sizes powder with good pellets fabrication characteristics. 2) The process is rather insensitive to most process variables, except nitric acid concentration. 3) Ambient temperature operations. 4) The losses of plutonium to the filtrate are less than in other conversion processes. (Author) [es

Radiolysis of water in the vicinity of passive surfaces

International Nuclear Information System (INIS)

Moreau, S.; Fenart, M.; Renault, J.P.

2014-01-01

Highlights: • HO° production through water radiolysis is enhanced near metal surfaces. • Hastelloy and Stainless steel surfaces can also produce HO° radicals through hydrogen peroxide activation. • There is a deficit in solvated electron production compared to hydroxyl radicals near metal surfaces. - Abstract: Porous metals were used to describe the water radiolysis in the vicinity of metal surfaces. The hydroxyl radical production under gamma irradiation was measured by benzoate scavenging in water confined in a 200 nm porous Ni base alloy or in Stainless steel. The presence of the metallic surfaces changed drastically the HO° production level and lifetime. The solvated electron production was measured via glycylglycine scavenging for Stainless steel and was found to be significantly smaller than hydroxyl production. These observations imply that interfacial radiolysis may deeply impact the corrosion behavior of the SS and Ni based alloys

Study of the radiolysis of water in porous media

International Nuclear Information System (INIS)

Rotureau, P.

2004-01-01

The understanding of the production of H 2 in the radiolysis of water confined into pores of concrete is important for the disposal of radioactive waste. In order to describe the mechanisms of water radiolysis in such heterogeneous porous systems we have studied the behaviour under gamma radiation of water confined in porous silica glasses with pores going from 8 to 300 nm of diameter and meso-porous molecular sieves (MCM-41). The radiolytic yields of hydroxyl radicals, hydrated electron and dihydrogen, have been determined with respect to the pore size of materials. The increase of these radiolytic yields compared to those of free water allowed us to show a charge transfer from silica to confined water. On the other hand the kinetics of hydrated electron reactions measured by pulse radiolysis are not modified. (author) [fr

A comparative study of thermodynamics in synergistic extraction of hexavalent plutonium by HTTA and HPMBP using mono- and bi-functional neutral donors

International Nuclear Information System (INIS)

Lohithakshan, K.V.; Mithapara, P.D.; Pai, S.A.; Aggarwal, S.K.

1996-01-01

Synergistic extraction of hexavalent plutonium was studied from HNO 3 medium (0.05 M) with HTTA and various neutral donors viz. DPSO, TBP, TOPO (monofunctional) and DBDECMP, DHDECMP, CMPO (bifunctional) using benzene as a diluent. Thermodynamic parameters (Δ G, Δ H, Δ S) were evaluated at 298 K from the experiments performed at four fixed temperatures in 288 to 318 K range. These were compared with the corresponding values reported earlier for Pu(VI) + HPMBP + neutral donor system. The net negative enthalpy changes with HTTA were observed to be low as compared to those with HPMBP. The net entropy changes were found to be either negligibly small (in cases of DPSO, TBP, DBDECMP, DHDECMP) or positive (in cases of CMPO, TOPO) with HTTA in comparison to large negative values with HPMBP. These results were interpreted in terms of different organic phase adduct formation reaction mechanisms i.e. substitution in HTTA vs. addition in HPMBP. Further, the lower net enthalpy changes with HTTA were explained due to a part of the energy used in release of water molecules bonded to plutonium in the plutonium chelate. (orig.)

Radiolysis of concentrated solutions. 1. Pulse and γ radiolysis studies of direct and indirect effects in LiCl solutions

International Nuclear Information System (INIS)

Pucheault, J.; Ferradini, C.; Julien, R.; Deysine, A.; Gilles, L.; Moreau, M.

1979-01-01

This study of the radiolysis of concentrated aqueous LiCl solutions enables the relative contributions of the direct and indirect effects to be evaluated as a function of Cl - concentration and also permits an evaluation of the role of Cl - in the early stages of water radiolysis. Radicalar and molecular yields G/sub Cl 2 - /, G/sub OH/, G//sub e//sub aq/ - / + G/sub H/, G/sub H 2 O 2 /, and G/sub H 2 / are determined for all concentrations employed, and the material balance is verified. The main conclusions concerning the apparent inefficacy of the direct effect and the importance of OH scavenging in spurs are discussed

Flexible plutonium management with IFR technology

International Nuclear Information System (INIS)

Hannum, W.H.; Lineberry, M.J.

1993-01-01

From the earliest days of the development of peaceful nuclear power, it has been recognized that efficient utilization of nuclear fuel resources requires a closed fuel cycle (recycle). With a closed cycle, essentially all the energy content of mined uranium can be used, whereas a once-through light water reactor (LWR) cycle uses only ∼0.5%. Since weapons programs have used the PUREX process to extract plutonium, it has further been assumed that this is the appropriate technology for closing the uranium fuel cycle. In the United States, these assumptions were put into question by concerns over commerce in separated plutonium and the threat of diversion of this material for weapons use

Influence of cow urine in the bioavailability of plutonium oxide particles in Palomares soils

Energy Technology Data Exchange (ETDEWEB)

Espinosa, A.; Aragon, A.; De La Cruz, B.; Gutierrez, J. [CIEMAT, DIAE, Madrid (Spain)

2004-07-01

The nuclear accident that occurred in Palomares in 1966 caused the release of plutonium weapon grade particles into a Mediterranean ecosystem, and consequently, urban and farming areas were contaminated with this material. Several studies focussed on the characterization and behaviour of trans-uranides have been carried out in the area. In this work, the solubility evolution of plutonium is analysed for a period of more than 30 years, as well as the influence that the incorporation of cow urine into organic fertilizers has on the solubility of the mentioned element. The average value of the plutonium solubility in water determined in five samples was 0.008% in 1986. However, determinations carried out in samples taken in 1999 and 2000 indicated an increase of the plutonium solubility of 22 to 96 times higher. In order to check the influence of organic fertilizers on the solubility of plutonium, a solubility test was carried out using cow urine as extracting solution. The results show that the solubility of plutonium can reach a value equal to 14%, which is similar to the one obtained with sodium pyrophosphate acting as extracting solution. Thus, these results are a clear warning of what might happen if organic fertilizers are used in transuranic-contaminated soils. (author)

Influence of cow urine in the bioavailability of plutonium oxide particles in Palomares soils

International Nuclear Information System (INIS)

Espinosa, A.; Aragon, A.; De La Cruz, B.; Gutierrez, J.

2004-01-01

The nuclear accident that occurred in Palomares in 1966 caused the release of plutonium weapon grade particles into a Mediterranean ecosystem, and consequently, urban and farming areas were contaminated with this material. Several studies focussed on the characterization and behaviour of trans-uranides have been carried out in the area. In this work, the solubility evolution of plutonium is analysed for a period of more than 30 years, as well as the influence that the incorporation of cow urine into organic fertilizers has on the solubility of the mentioned element. The average value of the plutonium solubility in water determined in five samples was 0.008% in 1986. However, determinations carried out in samples taken in 1999 and 2000 indicated an increase of the plutonium solubility of 22 to 96 times higher. In order to check the influence of organic fertilizers on the solubility of plutonium, a solubility test was carried out using cow urine as extracting solution. The results show that the solubility of plutonium can reach a value equal to 14%, which is similar to the one obtained with sodium pyrophosphate acting as extracting solution. Thus, these results are a clear warning of what might happen if organic fertilizers are used in transuranic-contaminated soils. (author)

Plutonium controversy

International Nuclear Information System (INIS)

Gofman, J.W.

1976-01-01

If the world chooses to seek a solution to the energy dilemma through nuclear energy, the element plutonium will become an article of commerce to be handled in quantities of thousands of tonnes annually. Plutonium is a uniquely potent inhalation carcinogen, the potential induction of lung cancer dwarfing other possible toxic effects. For reasons to be presented here, it is the author's opinion that plutonium's carcinogenicity has been very seriously underestimated. If one couples the corrected carcinogenicity with the probable degree of industrial containment of the plutonium, it appears that the commercialization of a plutonium-based energy economy is not an acceptable option for society. Sagan's statement that ''the experience of 30 years supports the contention that plutonium can be used safely'' is manifestly indefensible. No meaningful epidemiological study of plutonium-exposed workers for that 30-year period has ever been done. Since thousands of those possibly exposed have left the industry and are not even available to follow-up, it is doubtful that any meaningful study of ''the experience of 30 years'' will ever be accomplished

Preparation of hexavalent plutonium and its determination in the presence of tetravalent plutonium; Preparation de plutonium hexavalent et dosage en presence de plutonium tetravalent

Energy Technology Data Exchange (ETDEWEB)

Corpel, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Corpel, J [Institut du Radium, 75 - Paris (France)

1958-07-01

In order to study the eventual reduction of plutonium from the VI-valent state to the IV-valent state, in sulphuric medium, under the influence of its own {alpha} radiation or of the {gamma}-rays from a cobalt-60 source, we have developed a method for preparing pure hexavalent plutonium and two methods for determining solutions containing tetravalent and hexavalent plutonium simultaneously. Hexavalent plutonium was prepared by anodic oxidation at a platinum electrode. Study of the oxidation yield as a function of various factors has made it possible to define experimental conditions giving complete oxidation. For concentrations in total plutonium greater than 1.5 x 10{sup -3} M, determination of the two valencies IV and VI was carried out by spectrophotometry at two wavelengths. For lower concentrations, the determination was done by counting, after separation of the tetravalent plutonium in the form of fluoride in the presence of a carrier. (author) [French] Afin d'etudier l'eventuelle reduction du plutonium de l'etat de valence VI a l'etat de valence IV, en milieu sulfurique sous l'influence de son propre rayonnement {alpha} ou des rayons {gamma} d'une source de cobalt-60, nous avons mis au point une methode de preparation de plutonium hexavalent pur et deux methodes de dosage des solutions contenant simultanement du plutonium tetravalent et du plutonium hexavalent. Nous avons prepare le plutonium hexavalent par oxydation anodique au contact d'une electrode de platine. L'etude de rendement de l'oxydation en fonction des divers facteurs nous a permis de definir des conditions experimentales donnant une oxydation complete. Pour des concentrations en plutonium total superieures a 1,5.10{sup -3} M, le dosage des deux valences IV et VI a ete realise par spectrophotometrie a deux longueurs d'onde. Pour des concentrations inferieures, le dosage a ete effectue par comptage apres separation du plutonium tetravalent sous la forme du fluorure en presence d'un entraineur

Plutonium in nature

International Nuclear Information System (INIS)

Madic, C.

1994-01-01

Plutonium in nature comes from natural sources and anthropogenic ones. Plutonium at the earth surface comes principally from anthropogenic sources. It is easily detectable in environment. The plutonium behaviour in environment is complex. It seems necessary for the future to reduce releases in environment, to improve predictive models of plutonium behaviour in geosphere, to precise biological impact of anthropogenic plutonium releases

SEPARATION OF PLUTONIUM

Science.gov (United States)

Maddock, A.G.; Smith, F.

1959-08-25

A method is described for separating plutonium from uranium and fission products by treating a nitrate solution of fission products, uranium, and hexavalent plutonium with a relatively water-insoluble fluoride to adsorb fission products on the fluoride, treating the residual solution with a reducing agent for plutonium to reduce its valence to four and less, treating the reduced plutonium solution with a relatively insoluble fluoride to adsorb the plutonium on the fluoride, removing the solution, and subsequently treating the fluoride with its adsorbed plutonium with a concentrated aqueous solution of at least one of a group consisting of aluminum nitrate, ferric nitrate, and manganous nitrate to remove the plutonium from the fluoride.

Study of immiscibilities in the trilaurylamine - dodecane - nitric acid - plutonium system; Etude des immiscibilites dans le systeme trilaurylamine - dodecane - acide nitrique - plutonium

Energy Technology Data Exchange (ETDEWEB)

Saey, J C [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1968-07-01

Phase equilibrium in systems made up of trilaurylamine, dodecane, nitric acid tetravalent plutonium is shown by drawing the triangular diagrams. the study of these diagrams provides informations concerning the causes of immiscibility. Heterogeneity of the organic mixtures can be related to some characteristics of the components- dipole moment, molecular polarizability and hydrogen bond exchanging ability-Depending on these, some rules may be established which can be used to make a proper choice of an additive in order to improve the miscibility. As an application a study on the partial substitution of dodecane with decalin, in plutonium extraction experiments, has been done showing a possible improvement of the extraction process. (author) [French] L equilibre des phases dans les systemes formes a partir de trilaurylamine, de dodecane, d'acide nitrique et de plutonium tetravalent est represente en tracant les diagrammes triangulaires. L'examen de ces diagrammes permet d'apporter certaines precisions en ce qui concerne l'origine des immiscibilites. Celles ci sont ensuite reliees a certaines caracteristiques des constituants: le moment dipolaire, la polarisabilite moleculaire et la tendance a former des liaisons hydrogene. Sur les memes bases, il est possible d'etablir un certain nombre de regles pouvant servir a guider le choix d'un additif ameliorant la miscibilite. En application, une etude sur le remplacement partiel du dodecane par la decaline montre l'interet de l'emploi de ce compose dans le procede de purification du plutonium. (auteur)

Modelling the radiolysis of RSG-GAS primary cooling water

Science.gov (United States)

Butarbutar, S. L.; Kusumastuti, R.; Subekti, M.; Sunaryo, G. R.

2018-02-01

Water chemistry control for light water coolant reactor required a reliable understanding of radiolysis effect in mitigating corrosion and degradation of reactor structure material. It is known that oxidator products can promote the corrosion, cracking and hydrogen pickup both in the core and in the associated piping components of the reactor. The objective of this work is to provide the radiolysis model of RSG GAS cooling water and further more to predict the oxidator concentration which can lead to corrosion of reactor material. Direct observations or measurements of the chemistry in and around the high-flux core region of a nuclear reactor are difficult due to the extreme conditions of high temperature, pressure, and mixed radiation fields. For this reason, chemical models and computer simulations of the radiolysis of water under these conditions are an important route of investigation. FACSIMILE were used to calculate the concentration of O2 formed at relatively long-time by the pure water γ and neutron irradiation (pH=7) at temperature between 25 and 50 °C. This simulation method is based on a complex chemical reaction kinetic. In this present work, 300 MeV-proton were used to mimic γ-rays radiolysis and 2 MeV fast neutrons. Concentration of O2 were calculated at 10-6 - 106 s time scale.

The production control laboratories of the plutonium extraction Plant at Marcoule. Six years operating experience: 1957 - 1963

International Nuclear Information System (INIS)

Fontaine, A.

1964-01-01

In this paper, the author attempts to sum up the conditions prevailing, after six years of operation, in the Laboratories of the Plutonium Extraction Plant. The origins and objectives are briefly reviewed, the technology and staff recruitment policy are examined, and progress made is shown. The methods used as well as the scope of application and limits imposed at the present state are considered. Past achievements and further possibilities in the next future are examined. An attempt has been made to bring out the outlooks for the more distant future and to investigate the conditions required for the successful carrying out of the program. (author) [fr

Radiolysis effects in sub-cooled nucleate boiling

International Nuclear Information System (INIS)

Dickinson, S.; Henshaw, J.; Tuson, A.; Sims, H.E.

2002-01-01

A hydrogen depleted region may form in the water during bubble formation when boiling occurs in a PWR. This would arise from stripping of gases into the steam phase. The depleted water may then become oxidising due to radiolysis forming H 2 O 2 . The presence of radiolytic oxidising conditions is one of the mechanisms proposed to explain deposits formed in Axial Offset Anomalies. This work describes a model that has been developed to examine this behaviour. The model deals with bubble growth and material transport as well as the radiolysis chemistry. The model simulates diffusion of species through the gas/liquid boundary layer. The appropriate mass conservation equations for this problem are described and the results of their numerical solution discussed. This model indicates the importance of the assumed boundary conditions on the results of the calculations. These boundary conditions are discussed in detail and the most appropriate ones for the actual reactor situation are outlined. The conclusion of this modelling study is that at normal PWR operating conditions of 40 cc H 2 (STP) kg -1 it is unlikely that radiolysis in a subcooled boiling region would be important. The situation is more ambiguous at the 1 to 5 cc H 2 (STP) kg -1 range. (author)

Radiolysis effects in sub-cooled nucleate boiling

Energy Technology Data Exchange (ETDEWEB)

Dickinson, S.; Henshaw, J.; Tuson, A.; Sims, H.E. [AEA Technology (United Kingdom)

2002-07-01

A hydrogen depleted region may form in the water during bubble formation when boiling occurs in a PWR. This would arise from stripping of gases into the steam phase. The depleted water may then become oxidising due to radiolysis forming H{sub 2}O{sub 2}. The presence of radiolytic oxidising conditions is one of the mechanisms proposed to explain deposits formed in Axial Offset Anomalies. This work describes a model that has been developed to examine this behaviour. The model deals with bubble growth and material transport as well as the radiolysis chemistry. The model simulates diffusion of species through the gas/liquid boundary layer. The appropriate mass conservation equations for this problem are described and the results of their numerical solution discussed. This model indicates the importance of the assumed boundary conditions on the results of the calculations. These boundary conditions are discussed in detail and the most appropriate ones for the actual reactor situation are outlined. The conclusion of this modelling study is that at normal PWR operating conditions of 40 cc H{sub 2} (STP) kg{sup -1} it is unlikely that radiolysis in a subcooled boiling region would be important. The situation is more ambiguous at the 1 to 5 cc H{sub 2} (STP) kg{sup -1} range. (author)

The radiolysis of lithium oxide ceramics

Energy Technology Data Exchange (ETDEWEB)

Tiliks, J; Supe, A; Kizane, G; Tiliks, J Jr [Latvia Univ., Riga (Latvia). Dept. of Chemistry; Grishmanov, V; Tanaka, S

1998-03-01

The radiolysis of Li{sub 2}O ceramics exposed to accelerated electrons (5 MeV) at 380 K was studied in the range of high absorbed doses up to 250 MGy. The formation of radiation defects (RD) and radiolysis products (RP) was demonstrated to occur simultaneously in the regions of (1) the regular crystalline lattice and (2) an enhanced content of the intrinsic defects and impurities. The production of the electronic RD and RP is more efficient in the region of the defected lattice than that at the site of the regular crystalline lattice. However, the stability of RD and RP formed in the region of the intrinsic defects is far less than those produced at the crystalline lattice, since most of the first mentioned RD and RP disappears with irradiation dose due to the radiation stimulated recombination. By this means the enhanced quantity of RD and RP is localized in the Li{sub 2}O ceramics irradiated to absorbed dose of 40-50 MGy, and hence this can influence the tritium release parameters. As soon as the intrinsic defects have been consumed in the production of RD and RP and the recombination of unstable electronic RD and RP takes place (at dose of {approx}100 MGy), the radiolysis of Li{sub 2}O ceramics occurs only at the crystalline lattice. Furthermore, the concentration of RD and RP increases monotonically and tends to the steady-state level. (author)

Pulse radiolysis studies of model membranes

International Nuclear Information System (INIS)

Heijman, M.G.J.

1984-01-01

In this thesis the influence of the structure of membranes on the processes in cell membranes were examined. Different models of the membranes were evaluated. Pulse radiolysis was used as the technique to examine the membranes. (R.B.)

Plutonium isotopic determination from gamma-ray spectra

International Nuclear Information System (INIS)

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

1998-01-01

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

The effect of dissolved oxygen on water radiolysis behaviour

International Nuclear Information System (INIS)

Yakabuskie, P.A.; Joseph, J.M.; Wren, J.C.; Stuart, C.R.

2012-09-01

A quantitative understanding of the chemical or redox environments generated in water by ionizing radiation is important for material selection, development of maintenance programs, and safety assessments for water-cooled nuclear power reactors. The highly reactive radicals (·OH, ·H, ·e aq - , ·HO 2 , and ·O 2 - ) and molecular species (H 2 and H 2 O 2 ) generated by water radiolysis can compete in reactions with other dissolved compounds and impose changes to the system chemistry by altering the steady-state concentrations of water radiolysis products, which could impact the degradation of materials in contact with the aqueous phase. Understanding in detail how a given chemical additive changes the long-term radiolysis kinetics can help us to determine what chemistry control steps may be required to return the system to an optimal redox condition, and in turn, enhance the lifetime of reactor components. This study outlines the effect of dissolved oxygen gas, which could be introduced due to air ingress, on long-term water radiolysis behaviour. The effects of solution pH and initial dissolved O 2 concentration on the radiolytic production of molecular H 2 and H 2 O 2 have been investigated by performing experiments with three different O 2 concentrations at pH 6.0 and 10.6 under steady-state radiolysis conditions. The aqueous and gas phase analyses were performed using UV-Vis spectrophotometry and gas-chromatography equipped with electron capture and thermal conductivity detectors. The experimental results were compared with kinetic model calculations of steady-state radiolysis and were found to be in good agreement. The concentrations of water radiolysis products, H 2 O 2 and H 2 , were found to increase in the presence of dissolved oxygen, but the degree of increase was shown to depend on the solution pH. Furthermore, the steady-state concentration of H 2 did not increase as greatly as that of H 2 O 2 at either pH studied. The kinetic analyses have shown

Thermodynamics of synergistic extraction of hexavalent plutonium with HPMBP and neutral donors: monodentate versus bidentate

International Nuclear Information System (INIS)

Lohithakshan, K.V.; Mithapara, P.D.; Pai, S.A.; Aggarwal, S.K.; Jain, H.C.

1996-01-01

Synergistic extraction of hexavalent plutonium was studied from HNO 3 medium (0.05 M) with 1-phnyl, 3-methyl, 4-benzoyl, pyrazolone-5 (HPMBP) and different monodentate neutral donors viz. diphenyl sulphoxide (DPSO), tri-n-butyl phosphate (TBP) and tri-n-octyl phosphine oxide (TOPO) using benzene as a diluent. Thermodynamic parameters (ΔG, ΔH, ΔS) evaluated by performing the experiments at various fixed temperatures (288 K to 318 K) were compared with those reported previously for the bidentate neutral donors (DBDECMP, DHDECMP and CMPO). The net enthalpy changes were negative and comparable. The monodentate neutral donors, however, showed a larger decrease in the entropy values. Further, the negative values of enthalpy and entropy changes indicated that the organic adduct formation is an addition reaction as reported ealier for the bidentate donors. (orig.)

Radiolysis studies of uranyl nitrate solution in nitric acid medium

International Nuclear Information System (INIS)

Siri, Sandra; Mondino, Angel V.

2005-01-01

The radiolysis of acidic uranyl nitrate solutions was investigated using Co-60 gamma radiation. Hydrogen peroxide was determined as a function of increasing dose. The UV-vis absorption spectra of the irradiated solutions were measured and the spectral changes were analyzed. The increasing dose increases the absorbance intensities, possibly by an increment in nitrate concentration produced by radiolysis, which can originate the formation of different uranyl complexes in solution. (author)

Influence of chemisorption products of carbon dioxide and water vapour on radiolysis of tritium breeder

Energy Technology Data Exchange (ETDEWEB)

Zarins, Arturs, E-mail: arturs.zarins@lu.lv [University of Latvia, Institute of Chemical Physics, Kronvalda Boulevard 4, LV-1010 Riga (Latvia); Kizane, Gunta; Supe, Arnis [University of Latvia, Institute of Chemical Physics, Kronvalda Boulevard 4, LV-1010 Riga (Latvia); Knitter, Regina; Kolb, Matthias H.H. [Karlsruhe Institute of Technology, Institute for Applied Materials (IAM-WPT), 76021 Karlsruhe (Germany); Tiliks, Juris; Baumane, Larisa [University of Latvia, Institute of Chemical Physics, Kronvalda Boulevard 4, LV-1010 Riga (Latvia)

2014-10-15

Highlights: • Chemisorption products affect formation proceses of radiation-induced defects. • Radiolysis of chemisorption products increase amount of radiation-induced defects. • Irradiation atmosphere influence radiolysis of lithium orthosilicate pebbles. - Abstract: Lithium orthosilicate pebbles with 2.5 wt% excess of silica are the reference tritium breeding material for the European solid breeder test blanket modules. On the surface of the pebbles chemisorption products of carbon dioxide and water vapour (lithium carbonate and hydroxide) may accumulate during the fabrication process. In this study the influence of the chemisorption products on radiolysis of the pebbles was investigated. Using nanosized lithium orthosilicate powders, factors, which can influence the formation and radiolysis of the chemisorption products, were determined and described as well. The formation of radiation-induced defects and radiolysis products was studied with electron spin resonance and the method of chemical scavengers. It was found that the radiolysis of the chemisorption products on the surface of the pebbles can increase the concentration of radiation-induced defects and so could affect the tritium diffusion, retention and the released species.

The transport of plutonium nitrate liquor in the UK

International Nuclear Information System (INIS)

Barrett, T.R.; Wilson, D.; Bancroft, M.; Higson, J.

1994-01-01

The PFR fuel cycle reasons for plutonium nitrate liquor transport are discussed, identifying the pre 1980 'one litre' bottle associated with nuclear R and D activities and then the 250 litre PUNIT transport container to support the PFR fuel cycle. The PUNIT vessel design is discussed, addressing, in particular, the need for clean filling and criticality design features together with the identification of the IAEA transport regulations criteria and the late 1970s testing programme -the full scale drop tests and the model fire tests. Radiolysis is discussed together with the need for inert gas padding. The filling facility and operation are then outlined together with the fissile material accountancy requirements. The shipments and emergency arrangements are then described drawing attention to time and weather constraints. The risk assessment is discussed, together with reference to the Competent Authority (DoT) 'authorisation' and any constraints. A history of the amount of material transferred is then given - relating that to the reprocessing plant operations since 1980. The most satisfactory performance over 12 years is noted. (author)

The plutonium fuel cycles

International Nuclear Information System (INIS)

Pigford, T.H.; Ang, K.P.

1975-01-01

The quantities of plutonium and other fuel actinides have been calculated for equilibrium fuel cycles for 1000-MW water reactors fueled with slightly enriched uranium, water reactors fueled with plutonium and natural uranium, fast-breder reactors, gas-cooled reactors fueled with thorium and highly enriched uranium, and gas-cooled reactors fueled with thorium, plutonium and recycled uranium. The radioactivity quantities of plutonium, americium and curium processed yearly in these fuel cycles are greatest for the water reactors fueled with natural uranium and recycled plutonium. The total amount of actinides processed is calculated for the predicted future growth of the U.S. nuclear power industry. For the same total installed nuclear power capacity, the introduction of the plutonium breeder has little effect upon the total amount of plutonium in this century. The estimated amount of plutonium in the low-level process wastes in the plutonium fuel cycles is comparable to the amount of plutonium in the high-level fission product wastes. The amount of plutonium processed in the nuclear fuel cycles can be considerably reduced by using gas-cooled reactors to consume plutonium produced in uranium-fueled water reactors. These, and other reactors dedicated for plutonium utilization, could be co-located with facilities for fuel reprocessing ad fuel fabrication to eliminate the off-site transport of separated plutonium. (author)

Design guideline to prevent the pipe rupture by radiolysis gases in BWR steam piping

International Nuclear Information System (INIS)

Inagaki, T.; Miyagawa, M.; Ota, T.; Sato, T.; Sakata, K.

2009-01-01

In late 2001, pipe rupture accidents due to fast combustion of radiolysis gas occurred in Japan and elsewhere's BWR power plants. TENPES began to set up the guideline as action to such a new problem to prevent accumulation and combustion of radiolysis gas in BWR steam piping. And then, the first edition of guideline was published in October 2005. Afterwards, the experimental study about combustion/detonation of radiolysis gas have been continued. And in March 2007, TENPES published a revised edition of the guideline. This is the report of the revised edition of that guideline. According to this guideline, it became possible to design BWR's steam piping to prevent accumulation of radiolysis gas. (author)

IL 14: Radiolysis of water confined in nano-porous materials

International Nuclear Information System (INIS)

Renault, J.P.; Pommeret, S.; Musat, R.; Le Caer, S.; Alam, M.; Mialocq, J.C.

2010-01-01

Radiolysis of water in nano-porous media has raised a lot of interest and involved research in the recent years, with respect to concerns arising from the storage of nuclear waste. In the civil nuclear industry, storing for a long time nuclear wastes requires safety evaluations in order to test the durability of the materials involved. Among these materials, concrete and clays are a complex heterogeneous material that traps important quantities of interstitial water. Irradiation that arises from the nuclear wastes stored in these materials may lead to the radiolysis of the interstitial water, and the formation of radiolytic products, such as H 2 , O 2 or H 2 O 2 that may cause the breaking or the corrosion of the confining matrix. This communication will describe the possible impacts of confinement on the radiolysis of water. We will especially discuss the current knowledge about the evolution of radiolytic yields of primary species (hydroxyl radical, dihydrogen, aqueous electron) as a function of the degree of confinement and of the nature of the confining material. SEM picture of a nano-porous gold sample used to study the radiolysis of confined water The yield enhancement observed in many cases revealed original energy and charge transfer phenomena that we tried to decipher. (authors)

A Study of the 384 KeV Complex Gamma Emission from Plutonium-239

International Nuclear Information System (INIS)

Forsyth, R.S.; Ronqvist, N.

1965-11-01

Plutonium-239 has been reported to emit a gamma of energy 384 KeV. Subsequent workers, using radiation of this energy as a nondestructive measure of the plutonium content of various materials, found that the peak obtained by sodium iodide scintillation spectrometry showed a pronounced shoulder at about 330 KeV. This shoulder has been attributed to protactinium-233 and to uranium-237. From the width of the peak, however, it is obvious that at least three contributors are present. The present paper describes gamma spectrometric studies of plutonium samples of several isotopic compositions using a sodium iodide detector and a lithium-drifted germanium detector. The 384 KeV peak has been shown to be a complex peak containing 12 gamma components due to plutonium-239 between 300 - 450 KeV, and their relative intensities have been estimated. Anion exchange and solvent extraction experiments have also demonstrated that two further contributions due to uranium-237 are present in plutonium containing significant amounts of plutonium-241

A Study of the 384 KeV Complex Gamma Emission from Plutonium-239

Energy Technology Data Exchange (ETDEWEB)

Forsyth, R S; Ronqvist, N

1965-11-15

Plutonium-239 has been reported to emit a gamma of energy 384 KeV. Subsequent workers, using radiation of this energy as a nondestructive measure of the plutonium content of various materials, found that the peak obtained by sodium iodide scintillation spectrometry showed a pronounced shoulder at about 330 KeV. This shoulder has been attributed to protactinium-233 and to uranium-237. From the width of the peak, however, it is obvious that at least three contributors are present. The present paper describes gamma spectrometric studies of plutonium samples of several isotopic compositions using a sodium iodide detector and a lithium-drifted germanium detector. The 384 KeV peak has been shown to be a complex peak containing 12 gamma components due to plutonium-239 between 300 - 450 KeV, and their relative intensities have been estimated. Anion exchange and solvent extraction experiments have also demonstrated that two further contributions due to uranium-237 are present in plutonium containing significant amounts of plutonium-241.

Development of a new picosecond pulse radiolysis system by using a femtosecond laser synchronized with a picosecond linac. A step to femtosecond pulse radiolysis

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Yoichi; Yamamoto, Tamotsu; Miki, Miyako; Seki, Shu; Okuda, Shuichi; Honda, Yoshihide; Kimura, Norio; Tagawa, Seiichi [Osaka Univ., Ibaraki (Japan). Inst. of Scientific and Industrial Research; Ushida, Kiminori

1997-03-01

A new picosecond pulse radiolysis system by using a Ti sapphire femtosecond laser synchronized with a 20 ps electron pulse from the 38 MeV L-band linac has been developed for the research of the ultra fast reactions in primary processes of radiation chemistry. The timing jitter in the synchronization of the laser pulse with the electron pulse is less than several picosecond. The technique can be used in the next femtosecond pulse radiolysis. (author)

Plutonium

International Nuclear Information System (INIS)

Anon.

1995-01-01

Plutonium, which was obtained and identified for the first time in 1941 by chemist Glenn Seaborg - through neutron irradiation of uranium 238 - is closely related to the history of nuclear energy. From the very beginning, because of the high radiotoxicity of plutonium, a tremendous amount of research work has been devoted to the study of the biological effects and the consequences on the environment. It can be said that plutonium is presently one of the elements, whose nuclear and physico-chemical characteristics are the best known. The first part of this issue is a survey of the knowledge acquired on the subject, which emphasizes the sanitary effects and transfer into the environment. Then the properties of plutonium related to energy generation are dealt with. Fissionable, like uranium 235, plutonium has proved a high-performance nuclear fuel. Originally used in breeder reactors, it is now being more and more widely recycled in light water reactors, in MOX fuel. Reprocessing, recycling and manufacturing of these new types of fuel, bound of become more and more widespread, are now part of a self-consistent series of operations, whose technical, economical, industrial and strategical aspects are reviewed. (author)

Learning more about plutonium

International Nuclear Information System (INIS)

2005-01-01

This document offers chemical, metallurgical and economical information on the plutonium, a hard white radioelement. It deals also on the plutonium formation in the earth, the plutonium use in the nuclear industry, the plutonium in the environment and the plutonium toxicity. (A.L.B.)

Automated spectrophotometer for plutonium and uranium determination

International Nuclear Information System (INIS)

Jackson, D.D.; Hodgkins, D.J.; Hollen, R.M.; Rein, J.E.

1975-09-01

The automated spectrophotometer described is the first in a planned series of automated instruments for determining plutonium and uranium in nuclear fuel cycle materials. It has a throughput rate of 5 min per sample and uses a highly specific method of analysis for these elements. The range of plutonium and uranium measured is 0.5 to 14 mg and 1 to 14 mg, respectively, in 0.5 ml or less of solution with an option to pre-evaporate larger volumes. The precision of the measurements is about 0.02 mg standard deviation over the range corresponding to about 2 rel percent at the 1-mg level and 0.2 rel percent at the 10-mg level. The method of analysis involves the extraction of tetrapropylammonium plutonyl and uranyl trinitrate complexes into 2-nitropropane and the measurement of the optical absorbances in the organic phase at unique peak wavelengths. Various aspects of the chemistry associated with the method are presented. The automated spectrophotometer features a turntable that rotates as many as 24 samples in tubes to a series of stations for the sequential chemical operations of reagent addition and phase mixing to effect extraction, and then to a station for the absorbance measurement. With this system, the complications of sample transfers and flow-through cells are avoided. The absorbance measurement system features highly stable interference filters and a microcomputer that controls the timing sequence and operation of the system components. Output is a paper tape printout of three numbers: a four-digit number proportional to the quantity of plutonium or uranium, a two-digit number that designates the position of the tube in the turntable, and a one-digit number that designates whether plutonium or uranium was determined. Details of the mechanical and electrical components of the instrument and of the hardware and software aspects of the computerized control system are provided

Simulation study for purification, recovery of plutonium and uranium from plant streams of Fast Reactor Fuel Reprocessing Plant

International Nuclear Information System (INIS)

Sukumar, S.; Siva Kumar, P.; Radhika, R.; Subbuthai, S.; Mohan, S.V.; Subha Rao, R.V.

2005-01-01

A method for removal of plutonium from the lean organic streams obtained after co-stripping of uranium -plutonium was developed. Plutonium from lean organic phase was stripped using U 4+ /hydrazine as the stripping agent. The effect of concentrations of stripping agent U 4+ and feed Pu concentration in the lean organic phase was studied. Lean organic phases having higher plutonium concentration require three stages of stripping to bring plutonium concentration 4+ stabilized by hydrazine reduces Pu (IV) to Pu (III) thereby stripping plutonium from the organic phase. The non-extractability of Pu (III) by TBP was utilized for development of flow sheet for obtaining a uranium product lean of plutonium for ease of handling. (author)

Studies on removal of plutonium from oxalic acid containing hydrochloric acid solutions

Energy Technology Data Exchange (ETDEWEB)

Ghadse, D R; Noronha, D M; Joshi, A R [Fuel Chemistry Division, Bhabha Atomic Research Centre, Mumbai (India)

1994-06-01

Solution containing hydrochloric acid, oxalic acid and considerable quantities of plutonium may be generated while recycling of scrap produced during the metallic fuel fabrication. Plutonium from such waste is normally recovered by anion exchange method after the destruction of oxalic acid using suitable oxidising agent. Solvent extraction and ion exchange methods are being explored in this laboratory for recovery of Pu from oxalic acid containing HCl solutions without prior destruction of oxalic acid. This paper describes the results on the determination of distribution ratios for extraction of Pu(IV) from hydrochloric acid using Aliquot-336 or HDEHP under varying experimental conditions. (author). 5 refs., 5 tabs.

Early stages of methanol radiolysis from data of photoelectron spectroscopy and mass spectrometry

International Nuclear Information System (INIS)

Kalyazin, E.P.; Kovalev, G.V.

1982-01-01

Comparison of data on photoelectron spectroscopy and mass spectrometry permits to conclude that 4 types of molecular ions CH 3 O + H, H + CH 2 OH, H 3 C + OH and CH 3 O + H are initial products of methanol radiolysis. They start four parallel lines of methanol transformations. Mass spectrum of methanol can be evaluated according to the structural formula of methanol molecule. Composition of radiolysis products of gaseous methanol correlate satisfactorily with its mass spectrum. Reasons for the difference in compositions of radiolysis products of liquid and gaseous methanol are discussed

Pulse radiolysis of solutions of trans-stilbene

International Nuclear Information System (INIS)

Langan, J.R.; Salmon, G.A.

1982-01-01

On pulse radiolysis of solutions of trans-stilbene (t-St) in THF the radical-anion of t-St is formed by reaction of e - sub(s) with t-St. The transient absorption spectrum observed with lambdasub(max) at 500 and 720 nm is attributed to the unassociated St - . The subsequent decay of the radical-anion is accounted for by reaction with the counter-cation of THF formed on radiolysis and with radiolytically generated radicals; rate constants for these processes are estimated. Addition of sodium tetrahydridoaluminate (NAH) results in the radical-anion being associated with Na + as a contact ion-pair and a shift of lambdasub(max) to 490 nm. In the presence of the lithium salt the absorption spectrum of the radical-anion reverts to 500 nm. On pulse radiolysis of solutions containing NAH the main reaction forming St - is that of (Na + , e - sub(s))ion pairs with t-St. In addition there is a delayed formation of St - over a period of microseconds. The presence of tetrahydridoaluminate salts also greatly enhances the stability of St - and at high doses per pulse little decay was observed over 700 μs. The variation of G(St - ) with [NAH] was studied and was found to attain a plateau value of 2.0 at the higher concentrations. (author)

Preparation of fused chloride salts for use in pyrochemical plutonium recovery operations at Los Alamos

Energy Technology Data Exchange (ETDEWEB)

Fife, K.W.; Bowersox, D.F.; Christensen, D.C.; Williams, J.D.

1986-07-01

The Plutonium Metal Technology Group at Los Alamos routinely uses pyrochemical processes to produce and purify plutonium from impure sources. The basic processes (metal production, metal purification, and residue treatment) involve controlling oxidation and reduction reactions between plutonium and its compounds in molten salts. Current production methods are described, as well as traditional approaches and recent developments in the preparation of solvent salts for electrorefining, molten salt extraction, lean metal (pyroredox) purification, and direct oxide reduction.

Preparation of fused chloride salts for use in pyrochemical plutonium recovery operations at Los Alamos

International Nuclear Information System (INIS)

Fife, K.W.; Bowersox, D.F.; Christensen, D.C.; Williams, J.D.

1986-07-01

The Plutonium Metal Technology Group at Los Alamos routinely uses pyrochemical processes to produce and purify plutonium from impure sources. The basic processes (metal production, metal purification, and residue treatment) involve controlling oxidation and reduction reactions between plutonium and its compounds in molten salts. Current production methods are described, as well as traditional approaches and recent developments in the preparation of solvent salts for electrorefining, molten salt extraction, lean metal (pyroredox) purification, and direct oxide reduction

Civil plutonium management

International Nuclear Information System (INIS)

Sicard, B.; Zaetta, A.

2004-01-01

During 1960 and 1970 the researches on the plutonium recycling in fast neutrons reactors were stimulated by the fear of uranium reserves diminishing. At the beginning of 1980, the plutonium mono-recycling for water cooled reactors is implementing. After 1990 the public opinion concerning the radioactive wastes management and the consequences of the disarmament agreements between Russia and United States, modified the context. This paper presents the today situation and technology associated to the different options and strategical solutions of the plutonium management: the plutonium use in the world, the neutronic characteristics, the plutonium effect on the reactors characteristics, the MOX behavior in the reactors, the MOX fabrication and treatment, the possible improvements to the plutonium use, the concepts performance in a nuclear park. (A.L.B.)

The Reaction Mechanism and Rate Constants in the Radiolysis of Fe2+-Cu2+ Solutions

DEFF Research Database (Denmark)

Bjergbakke, Erling; Sehested, Knud; Rasmussen, O. Lang

1976-01-01

Pulse radiolysis and gamma radiolysis have been used to study the reaction mechanism in the radiolysis of aqueous solutions of Fe2+ and Cu2+. A reaction scheme has been developed and confirmed by computation of the corresponding complete set of differential equations. The rate constants for some ...... 10^{8}$ and $1.3\\times 10^{8}\\ {\\rm mol}^{-1}\\ {\\rm sec}^{-1}$ in pH 2.1 H2 SO4 and HClO4, respectively.......Pulse radiolysis and gamma radiolysis have been used to study the reaction mechanism in the radiolysis of aqueous solutions of Fe2+ and Cu2+. A reaction scheme has been developed and confirmed by computation of the corresponding complete set of differential equations. The rate constants for some...... of the reactions have been determined at different pH's. $k_{{\\rm Cu}^{+}+{\\rm O}_{2}}=4.6\\times 10^{5}$ and $1.0\\times 10^{6}\\ {\\rm mol}^{-1}\\ {\\rm sec}^{-1}$, $k_{{\\rm Cu}^{+}+{\\rm Fe}^{3+}}=5.5\\times 10^{6}$ and $1.3\\times 10^{7}\\ {\\rm mol}^{-1}\\ {\\rm sec}^{-1}$, $k_{{\\rm Cu}({\\rm III)}+{\\rm Fe}^{2+}}=3.3\\times...

Design safety features of containments used for handling plutonium in Reprocessing Plants

International Nuclear Information System (INIS)

Aherwal, P.; Achuthan, P.V.

2016-01-01

The plutonium present in spent fuel is separated from the associated uranium and fission products using solvent extraction cycles in process cells. Product plutonium nitrate solution containing trace concentrations of uranium and fission products is treated in the reconversion facility through a precipitation-calcination route and converted to sinterable grade plutonium oxide (PuO 2 ). All chemical operations involving materials with high plutonium content, both in solid and solution forms are carried out in glove boxes. Glove box provides an effective isolation from radioactive materials handled and acts as a barrier between the operator and the source of radiation. These glove boxes are interconnected for sequential operations and the interconnected glove box trains are installed within secondary enclosures called double skin which provides double barrier protection to operators

Radiolysis in cement-based materials ; application to radioactive waste-forms

International Nuclear Information System (INIS)

Bouniol, P.

2014-01-01

Cement-based materials appear to be an original environment with respect to radiolysis, due to their intrinsic complexity (porous, multiphasic and evolutional medium) or their very specific physico-chemical conditions (hyper-alkaline medium with pH ≥ 13, high content in calcium) or by the fact of numerous couplings existing between different phenomenologies. At the level of a radioactive cemented wasteform, a high degree of complexity is reached, in particular if the system communicates with the atmosphere (open system allowing regulation of the pressures but also the admission of O 2 , strong reactive with regards to radiolysis). Then, the radiolysis description exceeds widely the only one aspect of the decomposition of alkaline water under irradiation and makes necessary a global phenomenological approach. In this context, some 'outlying' phenomena, highly coupled with radiation chemistry, have to be taken into account because they contribute to deeply modify the net result of the radiolysis: radioactive decay of multiple αβγ emitters with filiation, phase changes (for example H 2 aq → H 2 gas) within the pores, gas transport by convection (Darcy law) and by diffusion (Fick law), precipitation/dissolution of solid phases, effect of the ionic strength and the temperature, disturbances connected to the presence of some solutes with redox potentialities (iron, sulphur). The integration work carried out on the previous points leads to an operational model (DOREMI) allowing the estimate of H 2 amounts produced by radiolysis in different cemented radioactive waste-forms. As the final expression of the model, numerical simulations constitute a relevant tool of expertise and prospecting, contributing to accompany the thought on radiolysis in cement matrices in general and in cemented waste-forms in particular. Starting from different examples, simulations can be so used in order to test some hypotheses or illustrate the greatest influence of gas transport, dose

Coolant radiolysis studies in the high temperature, fuelled U-2 loop in the NRU reactor

International Nuclear Information System (INIS)

Elliot, A.J.; Stuart, C.R.

2008-06-01

An understanding of the radiolysis-induced chemistry in the coolant water of nuclear reactors is an important key to the understanding of materials integrity issues in reactor coolant systems. Significant materials and chemistry issues have emerged in Pressurized Water Reactors (PWR), Boiling Water Reactors (BWR) and CANDU reactors that have required a detailed understanding of the radiation chemistry of the coolant. For each reactor type, specific computer radiolysis models have been developed to gain insight into radiolysis processes and to make chemistry control adjustments to address the particular issue. In this respect, modelling the radiolysis chemistry has been successful enough to allow progress to be made. This report contains a description of the water radiolysis tests performed in the U-2 loop, NRU reactor in 1995, which measured the CHC under different physical conditions of the loop such as temperature, reactor power and steam quality. (author)

Pulse radiolysis facilities and activities in Japan

International Nuclear Information System (INIS)

Ogasawara, M.

1995-01-01

Pulse radiolysis studies in Japan have been reviewed in special reference to the facilities and the people who have engaged in the experiments. Main achievement is summarized with the list of selected publications. (author)

Some plutonium IV polymers properties in Purex process

International Nuclear Information System (INIS)

Scoazec, H.; Pasquiou, J.Y.; Germain, M.

1990-01-01

The metabolism of plutonium polymers in fuel reprocessing using the Purex process with tributylphosphate as solvent, and its practical consequence in real operation conditions are examined. Precipitation with dibutylphosphoric acid, a solvent degradation product, occurs both in extraction and stripping units when polymers are present. (author)

The plutonium society

International Nuclear Information System (INIS)

Mez, L.; Richter, M.

1981-01-01

The lectures of an institute are reported on, which took place between 25th and 27th January 1980 in Berlin. The subsequent public panel discussion with representations from the political parties is then documentated in a few press-reports. The themes of the 8 lectures are: views and facts on plutonium, plutonium as an energy resource, military aspects of the production of plutonium, economic aspects of the plutonium economy, the position of the trade unions on the industrial reconversion, the alleged inevitability of a plutonium society and the socio-political alternatives and perspectives of nuclear waste disposal. (UA) [de

Selective extraction of plutonium from nitric acid medium by bifunctional polyethersulfone beads for quantification with thermal ionisation mass spectrometry

International Nuclear Information System (INIS)

Paul, Sumana; Aggarwal, S.K.; Pandey, A.K.

2015-01-01

Polyethersulfone (PES) magnetic beads were prepared by phase inversion technique. The beads were grafted with two monomers, viz. 2-hydroxyethylmethacrylate phosphoric acid (HEMP) and (3-acrylamidopropyl)trimethyl ammonium chloride (AMAC), by photo-induced free radical polymerization. Effect of different HNO 3 concentrations on the sorption profiles of Am(III) and Pu(IV) was studied using the grafted PES beads. The beads were found to extract plutonium quantitatively from high nitric acid medium (3-8 M). The effect of presence of competing actinide, e.g. U(VI), on the sorption of Pu(IV) was also studied. (author)

Alpha Radiolysis of Sorbed Water on Uranium Oxides and Uranium Oxyfluorides

Energy Technology Data Exchange (ETDEWEB)

Icenhour, A.S.

2003-09-10

The radiolysis of sorbed water and other impurities contained in actinide oxides has been the focus of a number of studies related to the establishment of criteria for the safe storage and transport of these materials. Gamma radiolysis studies have previously been performed on uranium oxides and oxyfluorides (UO{sub 3}, U{sub 3}O{sub 8}, and UO{sub 2}F{sub 2}) to evaluate the long-term storage characteristics of {sup 233}U. This report describes a similar study for alpha radiolysis. Uranium oxides and oxyfluorides (with {sup 238}U as the surrogate for {sup 233}U) were subjected to relatively high alpha radiation doses (235 to 634 MGy) by doping with {sup 244}Cm. The typical irradiation time for these samples was about 1.5 years, which would be equivalent to more than 50 years irradiation by a {sup 233}U sample. Both dry and wet (up to 10 wt % water) samples were examined in an effort to identify the gas pressure and composition changes that occurred as a result of radiolysis. This study shows that several competing reactions occur during radiolysis, with the net effect that only very low pressures of hydrogen, nitrogen, and carbon dioxide are generated from the water, nitrate, and carbon impurities, respectively, associated with the oxides. In the absence of nitrate impurities, no pressures greater than 1000 torr are generated. Usually, however, the oxygen in the air atmosphere over the oxides is consumed with the corresponding oxidation of the uranium oxide. In the presence of up to 10 wt % water, the oxides first show a small pressure rise followed by a net decrease due to the oxygen consumption and the attainment of a steady-state pressure where the rate of generation of gaseous components is balanced by their recombination and/or consumption in the oxide phase. These results clearly demonstrate that alpha radiolysis of either wet or dry {sup 233}U oxides will not produce deleterious pressures or gaseous components that could compromise the long-term storage of

Application of chemsimul for groundwater radiolysis

DEFF Research Database (Denmark)

Christensen, Hilbert; Bjergbakke, Erling

1986-01-01

The application of the radiation chemical computer program chemsimul, for the calculation of radiolysis in connection with the storage of high level waste has been studied. Methods have been developed for the diffusion of gases out of the irradiated system, for the continuous addition of Fe2...

Multi-Scale Modeling of the Gamma Radiolysis of Nitrate Solutions.

Science.gov (United States)

Horne, Gregory P; Donoclift, Thomas A; Sims, Howard E; Orr, Robin M; Pimblott, Simon M

2016-11-17

A multiscale modeling approach has been developed for the extended time scale long-term radiolysis of aqueous systems. The approach uses a combination of stochastic track structure and track chemistry as well as deterministic homogeneous chemistry techniques and involves four key stages: radiation track structure simulation, the subsequent physicochemical processes, nonhomogeneous diffusion-reaction kinetic evolution, and homogeneous bulk chemistry modeling. The first three components model the physical and chemical evolution of an isolated radiation chemical track and provide radiolysis yields, within the extremely low dose isolated track paradigm, as the input parameters for a bulk deterministic chemistry model. This approach to radiation chemical modeling has been tested by comparison with the experimentally observed yield of nitrite from the gamma radiolysis of sodium nitrate solutions. This is a complex radiation chemical system which is strongly dependent on secondary reaction processes. The concentration of nitrite is not just dependent upon the evolution of radiation track chemistry and the scavenging of the hydrated electron and its precursors but also on the subsequent reactions of the products of these scavenging reactions with other water radiolysis products. Without the inclusion of intratrack chemistry, the deterministic component of the multiscale model is unable to correctly predict experimental data, highlighting the importance of intratrack radiation chemistry in the chemical evolution of the irradiated system.

The Plutonium Fuel Laboratory at Studsvik and Its Activities

Energy Technology Data Exchange (ETDEWEB)

Hultgren, A.; Berggren, G.; Brown, A.; Eng, H. U.; Forsyth, R. S. [AB Atomenergi, Studsvik (Sweden)

1967-09-15

The plutonium fuel laboratory at Studsvik is engaged in development work on plutonium-enriched fuel. At present, low enriched fuel for thermal reactors is being studied: work on fuel with a higher plutonium content for fast reactors is foreseen at a later date. So far only the pellet technique is under consideration, and a number of pellet rod specimens will be produced and irradiated in the reactor R2. These specimens include pellets from both co-precipitated uranium-plutonium salts and from physically mixed oxides. Comparison of these two materials will be extended to different density levels and different heat ratings. The methods and techniques used and studied include wet chemical work for powder preparation (continuous precipitation of Pu(IV)-oxalate with oxalic acid, continuous co-precipitation of plutonium and uranium with ammonia, optimization of.precipitation conditions using U(IV) and U(VI) respectively) ; powder preparation (drying, calcination, reduction, mixing, milling, binder addition, granulation); pellet preparation (pressing, debonding, sintering, inspection): encapsulation (charging, welding of end plug, helium filling, end sealing by welding, leak detection, decontamination); metallography (specimen preparation (moulding, polishing), etching, microscopy); structure investigations (thermal analysis (TG, DTA), X-ray diffraction, neutron diffraction, data handling by computer analysis); radiometric methods (direct plutonium determination by gamma spectrometry, non-destructive burn-up analysis by high resolution gamma spectrometry, using a Ge(Li) detector) ; rework of waste (recovery of plutonium from fuel waste by extraction with trilauryl amine and anion exchange). The plutonium fuel laboratory forms part of the Active Central Laboratory. The equipment is contained in four adjacent 10 x 15 m rooms; .for diffraction work and inactive uranium work additional space is available. All the forty glove boxes in operation except two are of AB Atomenergi

What is plutonium stabilization, and what is safe storage of plutonium?

International Nuclear Information System (INIS)

Forsberg, C.W.

1995-01-01

The end of the cold war has resulted in the shutdown of nuclear weapons production and the start of dismantlement of significant numbers of nuclear weapons. This, in turn, is creating an inventory of plutonium requiring interim and long-term storage. A key question is, ''What is required for safe, multidecade, plutonium storage?'' The requirements for storage, in turn, define what is needed to stabilize the plutonium from its current condition into a form acceptable for interim and long-term storage. Storage requirements determine if research is required to (1) define required technical conditions for interim and long-term storage and (2) develop or improve current stabilization technologies. Storage requirements depend upon technical, policy, and economic factors. The technical issues are complicated by several factors. Plutonium in aerosol form is highly hazardous. Plutonium in water is hazardous. The plutonium inventory is in multiple chemical forms--some of which are chemically reactive. Also, some of the existing storage forms are clearly unsuitable for storage periods over a few years. Gas generation by plutonium compounds complicates storage: (1) all plutonium slowly decays creating gaseous helium and (2) the radiation from plutonium decay can initiate many chemical reactions-some of which generate significant quantities of gases. Gas generation can pressurize sealed storage packages. Last nuclear criticality must be avoided

Continuous plutonium(IV) oxalate precipitation, filtration, and calcination process. [From product streams from Redox, Purex, or Recuplex solvent extraction plants

Energy Technology Data Exchange (ETDEWEB)

Beede, R L

1956-09-27

A continuous plutonium (IV) oxalate precipitation, filtration, and calcination process has been developed. Continuous and batch decomposition of the oxalate in the filtrates has been demonstrated. The processes have been demonstrated in prototype equipment. Plutonium (IV) oxalate was precipitated continuously at room temperature by the concurrent addition of plutonium (IV) nitrate feed and oxalic acid into the pan of a modified rotary drum filter. The plutonium (IV) oxalate was calcined to plutonium dioxide, which could be readily hydrofluorinated. Continuous decomposition of the oxalate in synthetic plutonium (IV) oxalate filtrates containing plutonium (IV) oxalate solids was demonstrated using co-current flow in a U-shaped reactor. Feeds containing from 10 to 100 g/1 Pu, as plutonium (IV) nitrate, and 1.0 to 6.5 M HNO/sub 3/, respectively, can be processed. One molar oxalic acid is used as the precipitant. Temperatures of 20 to 35/sup 0/C for the precipitation and filtration are satisfactory. Plutonium (IV) oxalate can be calcined at 300 to 400/sup 0/C in a screw-type drier-calciner to plutonium dioxide and hydrofluorinated at 450 to 550/sup 0/C. Plutonium dioxide exceeding purity requirements has been produced in the prototype equipment. Advantages of continuous precipitation and filtration are: uniform plutonium (IV) oxalate, improved filtration characteristics, elimination of heating and cooling facilities, and higher capacities through a single unit. Advantages of the screw-type drier-calciner are the continuous production of an oxide satisfactory for feed for the proposed plant vibrating tube hydrofluorinator, and ease of coupling continuous precipitation and filtration to this proposed hydrofluorinator. Continuous decomposition of oxalate in filtrates offers advantages in decreasing filtrate storage requirements when coupled to a filtrate concentrator. (JGB)

Radiolysis study of the radical-like action mechanisms of an antioxidant: Sulfarlem

International Nuclear Information System (INIS)

Ruimy-Ifrah, Pascale

1989-01-01

Sulfarlem or p-anisyldithiolthione (ADT) is a sulfured heterocyclic compound which exhibits antioxidant properties. This work presents the quantitative study of the mono-electronic exchange mechanisms involved in this action. This study has been performed by gamma radiolysis and pulse radiolysis. The gamma radiolysis of ADT aerated ethanolic solutions has shown that O 2 . and RO 2 . radicals are not reactive towards ADT. In return, ADT is an efficient scavenger of R . radicals; the rate constant of this reaction being k (ADT + R . ) = 6.7 x 10 4 mol -1 .l.s -1 . The pulse radiolysis experiments allowed the characterization of ADT reduction by the solvated electron (k (e solv - + ADT) = 2.3 x 10 10 mol -1 .l.s -1 ), the determination of the absorption spectrum of the reduced species A . (maximum wavelength = 580 nm) and the rate constant of its evolution (k (A . + A . ) = 5.7 x 10 8 mol -1 .l.s -1 ). An analogous study has been performed with ADO, an ADT oxidized derivative, which appeared to be a less efficient free radicals scavenger. (author) [fr

Radiolysis of actinides and technetium in alkaline media

Energy Technology Data Exchange (ETDEWEB)

Delegard, C.H., Westinghouse Hanford

1996-07-10

The {gamma}-radiolysis of aerated alkaline aqueous solutions of Np(V), Np(VI), Pu(VI), Tc(IV), Tc(V), and TC(VII) was studied in the absence of additives and in the presence of CO{sub 3}{sup 2-}, NO{sub 3}{sup -}, NO{sub 2}{sup -}, EDTA, formate, and other organic compounds. The radiolytic reduction of Np(V), Np(VI), Pu(VI), and TC(VII) under different experimental conditions was examined in detail. The addition of EDTA, formate, and alcohols was found to considerably increase the radiation-chemical reduction yields. The formation of the Np(V) peroxo complex was observed in the {gamma}-radiolysis of alkaline aqueous solutions of Np (VI) in the presence of nitrate.

Determination of the clean 4f peak shape in XPS for plutonium metal

Energy Technology Data Exchange (ETDEWEB)

Morrall, P. [AWE, Aldermaston, Reading, Berkshire RG7 4PR (United Kingdom)], E-mail: peter.morrall@awe.co.uk; Roussel, P. [AWE, Aldermaston, Reading, Berkshire RG7 4PR (United Kingdom); Jolly, L.; Brevet, A.; Delaunay, F. [Commissariat a l' Energie Atomique, Centre de Valduc, 21120 Is-sur-Tille (France)

2009-03-15

Many of the interesting properties observed with plutonium are ascribed to the influence of 5f electrons, and to the degree of localisation observed within these electrons. Indeed, changes in 5f localisation are sensitively reflected in the final states observed in core-level photoemission measurements. However, when analysing the 4f manifold of elemental plutonium, it is essential to obtain spectra without the influence of oxidation, which can easily be misinterpreted as 5f localisation. The ideal method to extract elemental plutonium 4f spectra is to remove any influence of oxidation from the 'clean' plutonium data by careful measurement of the oxygen 1s region, and the subsequent subtraction of the unwanted oxide features. However, in order to achieve this objective it is essential to determine the relative sensitivity factor (RSF) for plutonium 4f and the precise shape of the 4f features from plutonium sesqui-oxide. In this paper, we report an experimental determination of the RSF for the plutonium 4f manifold using experimental data captured from two different Vacuum Generators spectrometers; an ESCALAB Mk II and an ESCALAB 220i.

Plutonium solubilities

International Nuclear Information System (INIS)

Puigdomnech, I.; Bruno, J.

1991-02-01

Thermochemical data has been selected for plutonium oxide, hydroxide, carbonate and phosphate equilibria. Equilibrium constants have been evaluated in the temperature range 0 to 300 degrees C at a pressure of 1 bar to T≤100 degrees C and at the steam saturated pressure at higher temperatures. Measured solubilities of plutonium that are reported in the literature for laboratory experiments have been collected. Solubility data on oxides, hydroxides, carbonates and phosphates have been selected. No solubility data were found at temperatures higher than 60 degrees C. The literature solubility data have been compared with plutonium solubilities calculated with the EQ3/6 geochemical modelling programs, using the selected thermodynamic data for plutonium. (authors)

Plutonium in uranium deposits

International Nuclear Information System (INIS)

Curtis, D.; Fabryka-Martin, J.; Aguilar, R.; Attrep, M. Jr.; Roensch, F.

1992-01-01

Plutonium-239 (t 1/2 , 24,100 yr) is one of the most persistent radioactive constituents of high-level wastes from nuclear fission power reactors. Effective containment of such a long-lived constituent will rely heavily upon its containment by the geologic environment of a repository. Uranium ore deposits offer a means to evaluate the geochemical properties of plutonium under natural conditions. In this paper, analyses of natural plutonium in several ores are compared to calculated plutonium production rates in order to evaluate the degree of retention of plutonium by the ore. The authors find that current methods for estimating production rates are neither sufficiently accurate nor precise to provide unambiguous measures of plutonium retention. However, alternative methods for evaluating plutonium mobility are being investigated, including its measurement in natural ground waters. Preliminary results are reported and establish the foundation for a comprehensive characterization of plutonium geochemistry in other natural environments

Conversion of metal plutonium to plutonium dioxide by pyrochemical method

Energy Technology Data Exchange (ETDEWEB)

Panov, A.V.; Subbotin, V.G. [Russian Federal Nuclear Center, ALL-Russian Science and Research Institute of Technical Physics, Snezhinsk (Russian Federation); Mashirev, V.P. [ALL-Russian Science and Research Institute of Chemical Technology, Moscow (Russian Federation)

2000-07-01

Report contains experimental results on metal plutonium of weapon origin samples conversion to plutonium dioxide by pyrochemical method. Circuits of processes are described. Their advantages and shortcomings are shown. Parameters of plutonium dioxide powders (phase and fraction compositions, poured density) manufactured by pyrochemical method in RFNC-VNIITF are shown as well. (authors)

The use of plutonium

International Nuclear Information System (INIS)

Marshall, W.

1980-01-01

The use of plutonium as a vital energy source producing maximum economic benefit with minimum proliferation risks is discussed. Having considered the production of plutonium, several possible plutonium fuel cycle options are identified and the economic value to be attached to plutonium for each examined. It is shown how the use of plutonium in fast reactors gives an opportunity for a non-proliferation policy not available when plutonium is used only in thermal reactors. From the technical considerations reviewed concerning plutonium and fast reactors it is shown that an economic regime involving international trade in spent thermal reactor fuel is possible which benefits equally those countries with fast reactors and those without and also assists in avoiding the proliferation of nuclear weapons. (U.K.)

Properties of plutonium

International Nuclear Information System (INIS)

Ahn, Jin Su; Yoon, Hwan Ki; Min, Kyung Sik; Kim, Hyun Tae; Ahn, Jong Sung; Kwag, Eon Ho; Ryu, Keon Joong

1996-03-01

Plutonium has unique chemical and physical properties. Its uniqueness in use has led to rare publications, in Korea. This report covers physical aspects of phase change of metal plutonium, mechanical properties, thermal conductivity, etc, chemical aspects of corrosion, oxidation, how to produce plutonium from spent fuels by describing various chemical treatment methods, which are currently used and were used in the past. It also contains characteristics of the purex reprocessing process which is the most widely used nowadays. And show processes to purify and metalize from recovered plutonium solution. Detection and analysis methods are introduced with key pints for handling, critical safety, toxicity, and effects on peoples. This report gives not only a general idea on what plutonium is, rather than deep technical description, but also basic knowledge on plutonium production and safeguards diversion from the view point of nonproliferation. 18 refs. (Author) .new

Properties of plutonium

Energy Technology Data Exchange (ETDEWEB)

Ahn, Jin Su; Yoon, Hwan Ki; Min, Kyung Sik; Kim, Hyun Tae; Ahn, Jong Sung; Kwag, Eon Ho; Ryu, Keon Joong [Korea Atomic Energy Research Institute, Daeduk (Korea, Republic of)

1996-03-01

Plutonium has unique chemical and physical properties. Its uniqueness in use has led to rare publications, in Korea. This report covers physical aspects of phase change of metal plutonium, mechanical properties, thermal conductivity, etc, chemical aspects of corrosion, oxidation, how to produce plutonium from spent fuels by describing various chemical treatment methods, which are currently used and were used in the past. It also contains characteristics of the purex reprocessing process which is the most widely used nowadays. And show processes to purify and metalize from recovered plutonium solution. Detection and analysis methods are introduced with key pints for handling, critical safety, toxicity, and effects on peoples. This report gives not only a general idea on what plutonium is, rather than deep technical description, but also basic knowledge on plutonium production and safeguards diversion from the view point of nonproliferation. 18 refs. (Author) .new.

Plutonium-238 and plutonium-239 metabolism in dairy cows following ingestion of mixed oxides

International Nuclear Information System (INIS)

Patzer, R.G.; Mullen, A.A.; Sutton, W.W.; Potter, G.D.; Mosley, R.E.; Efurd, D.W.; Stalnaker, N.D.

1985-01-01

Dairy cows were given oral dosage of plutonium-238 and plutonium-239 dioxide particles in a study to determine the relative gastrointestinal absorption and tissue distribution of the nuclides. Two cows were given particles in which the two isotopes were homogeneously mixed within the particles. A third cow was given two batches of particles which contained either plutonium-238 or plutonium-239. Results indicate that, when the two isotopes of plutonium are homogeneous within the particles, there is no difference between plutonium-238 and plutonium-239 in the relative gastrointestinal absorption and tissue distribution

High-temperature enthalpies of plutonium monocarbide and plutonium sesquicarbide

International Nuclear Information System (INIS)

Oetting, F.L.

1979-01-01

The high-temperature enthalpies of plutonium monocarbide and plutonium sesquicarbide have been determined with a copper-block calorimeter of the isoperibol type. The experimental enthalpy data, which was measured relative to 298 K, covered the temperature range from 400 to 1500 K. The calculation of the temperature rise of the calorimeter takes into account the added heat evolution from the radioactive decay of the plutonium samples. These enthalpy results, combined with the heat capacity and entropy of the respective carbide at 298 K available from the literature, has made it possible to generate tables of thermodynamic functions for the plutonium carbides. The behavior of the heat capacity of both of the plutonium carbides, i.e., a relatively steep increase in the heat capacity as the temperature increases, may be attributed to a premelting effect with the formation of vacancies within the crystal lattice although a theoretical treatment of this phenomenon is not given

Extraction of actinides from chloride medium using pentaalkylpropanediamides

International Nuclear Information System (INIS)

Cuillerdier, C.; Musikas, C.

1991-01-01

Pyrometallurgical processes for the purification of plutonium create waste solutions containing actinides, mainly americium, in chloride medium. Studies have been undertaken to study the extraction of actinides in chloride medium (hydrochloric acid mixed with concentrated salts such as LiCl, CaCl 2 , MgCl 2 , KCl) using pentaalkylpropanediamides as extractants. Plutonium (IV) is very easily extracted, Am (III) needs a salting out agent such as LiCl. Back extraction of trivalent cations is easy in HCl <5M. Plutonium(IV) and (VI) can be stripped by reduction either with ascorbic acid or hydroxylammonium salts in weak acid medium. Several diluents can be used (aromatic, chlorinated or even aliphatic) with addition of decanol to prevent third phase formation. In conclusion diamides can be used for various wastes declassification, they are potentially completely incinerable, and, as the synthesis has been optimized, they appear to be promising extractants

The investigation of the n-#betta#-radiolysis of nitrogen tetroxide under super-critical conditions

International Nuclear Information System (INIS)

Nesterenko, V.B.; Gvozdev, A.A.; Doroshkevich, V.N.; Nichipor, G.V.; Trubnikov, V.P.

1983-01-01

The yield of the 'irreversible' products of nitrogen tetroxide radiolysis has been determined in stainless steel ampoules in the field of the reactor mixed radiation; Radiolysis has been investigated in the range of temperatures 200 to 350 deg C, pressures 7.8 to 15.7 MPa and dose rates 48 and 162 W/kg. The measured primary yield of nitrogen atoms under nitrogen dioxide radiolysis is equal to 0.28 + 0.02 at/100 eV at 250 deg C. It is shown that in the investigated range of temperatures and pressures the yield of the 'irreversible' radiolysis products can be determined using the known kinetic data on the reactions of nitrogen atoms with molecules and assuming the primary yield of nitrogen atoms from nitrogen dioxide and nitric oxide equal to 0.28 and 4.5 at/100 eV respectively. (author)

Development of polymer-extractant composite beads for separation of radionuclides

International Nuclear Information System (INIS)

Kumar, Manmohan; Singh, Krishankant; Bajaj, P.N.

2009-01-01

A novel micro porous polymer-extractant composite bead system, containing liquid extractant encapsulated in the core of a polymeric shell, with required porosity and hydrophilicity, to allow exchange of radionuclides without, any significant leaching out of the encapsulated extractant, has been developed for solid-liquid extraction of radionuclides from acidic waste solutions. The reuse of the beads is possible as there is practically no change in its radionuclide extraction efficiency, after repeated extraction second time. The high porosity and hydrophilicity of the synthesized TBP-encapsulated polymeric beads is evident from the presence of ∼ 78% water in the swollen condition. Evaluation of the synthesized beads for extraction of uranium and plutonium from aqueous acidic waste solutions, indicated possibility of their use under the conditions of PUREX process. The aliquate 336-encapsulated polymeric beads showed selective extraction of plutonium from aqueous nitrate solutions in the presence of uranium, and back extraction of the loaded plutonium, using dilute nitric acid or ascorbic acid. (author)

An experimental study of factors in the recovery of plutonium from combustible wastes treated by incineration, pyrolysis and other processes

International Nuclear Information System (INIS)

Bamber, D.C.; McDonald, L.A.; Roberts, W.G.; Sutcliffe, P.W.; Wilkins, J.D.

1984-01-01

The work described in this report is concerned with the incineration and pyrolysis of plutonium-contaminated combustible wastes, the leaching of the ashes and chars and the subsequent treatment of the leach solutions. A range of ashes and chars have been prepared from a range of plutonium-contaminated materials covering a variety of combustible materials (e.g. PVC, neoprene, Hypalon) and plutonium contaminants [e.g. PuO 2 , Pu(NO 3 ) 4 , (U, Pu)O 2 ]. Treatment temperatures in the range of 550-900 0 C have been investigated, the best results being obtained at or below 700 0 C with pyrolysis followed by char oxidation being the favoured process. A number of methods for treatment of the leach solutions have been considered and some have been investigated experimentally. Extraction of plutonium and americium with tributylphosphate (TBP) from a leach solution conditioned to 0.1 M H/+5 M NO 3 - has been studied. The key stage has been found to be the conditioning step where precautions must be taken to ensure that plutonium-containing precipitates and non-extractable plutonium are not formed. Consideration has also been given to treatment of the americium containing raffinates from a high acid TBP extraction and some methods have been investigated. A range of simple washing experiments have been carried out in order to compare the process with incineration/pyrolysis

Plutonium

International Nuclear Information System (INIS)

Koelzer, W.

1989-03-01

This report contains with regard to 'plutonium' statements on chemistry, occurrence and reactions in the environment, handling procedures in the nuclear fuel cycle, radiation protection methods, biokinetics, toxicology and medical treatment to make available reliable data for the public discussion on plutonium especially its use in nuclear power plants and its radiological assessment. (orig.) [de

Plutonium

International Nuclear Information System (INIS)

Mueller-Christiansen, K.; Wollesen, M.

1979-01-01

As emotions and fear of plutonium are neither useful for the non-professionals nor for the political decision makers and the advantages and disadvantages of plutonium can only put against each other under difficulties, the paper wants to present the most essential scientific data of plutonium in a generally understandable way. Each of the individual sections is concluded and they try to give an answer to the most discussed questions. In order to make understanding easier, the scientific facts are only brought at points where it cannot be done without for the correctness of the presentation. Many details were left out knowingly. On the other hand, important details are dealt with several times if it seems necessary for making the presentation correct. The graphical presentations and the figures in many cases contain more than said in the text. They give the interested reader hints to scientific-technical coherences. The total material is to enable the reader to form his own opinion on plutonium problems which are being discussed in public. (orig./HP) [de

A pulse radiolysis study of the formation and reactions of reduced metal EDTA complexes

International Nuclear Information System (INIS)

Buitenhuis, R.

1977-01-01

The construction of a computerized pulse radiolysis system with available means appropriate for the wavelength interval between 300 and 1000 nm is described. The investigation of the radiolysis of aqueous solutions of EDTA complexes in the presence of alcohols is discussed

PRODUCTION OF PLUTONIUM METAL

Science.gov (United States)

Lyon, W.L.; Moore, R.H.

1961-01-17

A process is given for producing plutonium metal by the reduction of plutonium chloride, dissolved in alkali metal chloride plus or minus aluminum chloride, with magnesium or a magnesium-aluminum alloy at between 700 and 800 deg C and separating the plutonium or plutonium-aluminum alloy formed from the salt.

Concentration and purification of plutonium solutions by means of ion-exchange columns

Energy Technology Data Exchange (ETDEWEB)

Durham, R W; Aikin, A M

1953-02-15

Equilibrium experiments using Dowex 50 ion-exchange resin and nitric acid solutions of Pu{sup 3+}, UO{sub 2}{sup 2+}, Fe{sup 2+} cations have yielded values for the absorption affinities for these ions. Trivalent plutonium was found to be far more strongly absorbed than UO{sub 2}{sup 2+} and Fe{sup 2+}. Column studies have shown that uranium can be completely separated from plutonium even when the initial concentration of uranium is very much greater than that of the plutonium. A plutonium concentration increase of about fifty-fold can be obtained from solutions about 10{sup -3} M in plutonium and 1.0M in nitric acid. The equation K{sub Pu}{sup 3+} = X{sub R} (1-X{sub S}){sup 3} C{sub S}{sup 2}/X{sub S} (1-X{sub R}){sup 3} C{sub R}{sup 2} for estimating the maximum amount of plutonium taken up by a column of resin of unit volume from a solution of total equivalent concentration, C{sub S} , has been shown to hold for values of C{sub S} up to 3 equivalents per litre. X{sub R}, the equivalent fraction of plutonium on the resin, is the number of equivalents of plutonium absorbed by the resin divided by the total capacity of the column. X{sub S}, the equivalent fraction of plutonium in solution, is the equivalent concentration of plutonium divided by the total equivalent concentration of cations in solution. C{sub R} is the total capacity of the resin in milli-equivalents per gram of dry resin. Recommendations have been made for the application and operation of ion-exchange columns in the Plutonium-Extraction Plant. (author)

Plutonium storage phenomenology

International Nuclear Information System (INIS)

Szempruch, R.

1995-12-01

Plutonium has been produced, handled, and stored at Department of Energy (DOE) facilities since the 1940s. Many changes have occurred during the last 40 years in the sources, production demands, and end uses of plutonium. These have resulted in corresponding changes in the isotopic composition as well as the chemical and physical forms of the processed and stored plutonium. Thousands of ordinary food pack tin cans have been used successfully for many years to handle and store plutonium. Other containers have been used with equal success. This paper addressees the exceptions to this satisfactory experience. To aid in understanding the challenges of handling plutonium for storage or immobilization the lessons learned from past storage experience and the necessary countermeasures to improve storage performance are discussed

Gamma-radiolysis of aqueous solutions of methyl orange and chrysoidine

International Nuclear Information System (INIS)

Khabarov, V.N.; Kozlov, L.L.; Panchenkov, G.M.

1980-01-01

Radiation-chemical bleaching of azo dyes of methyl orange and chrysoidine in aqueous and aqueous-alcoholic solutions under the effect of γ-radiation of 60 Co is studied. The effect of different additions and pH value of medium upon radiolysis of azo dyes is investigated. Radiation-chemical yields of the bleaching are determined. Quantitative connection between the initial yields of water radiolysis products and radiation yields of the bleaching of azo dyes is established. On the basis of the results obtained the most probable mechanism of methyl orange and chrysoidine bleaching is suggested

Formation and role of excited states in radiolysis - a foreword

International Nuclear Information System (INIS)

Singh, A.

1976-01-01

It is stated that the choice of contributions to the special issue of this Journal has been limited to those which bear on the details of the mechanisms of excited state formation and are likely to be useful to radiation chemists. Since more than half the energy deposited in radiolysis goes into excitation, studies on the fate of the excited species formed are very important. A brief reference is made to the subject matter of each of the fifteen contributions, and its significance to the development of the technique of radiolysis is outlined. (U.K.)

Partitioning of plutonium and uranium in aqueous medium using hydroxyurea as reducing agent

International Nuclear Information System (INIS)

Sivakumar, P.; Subba Rao, R.V.; Meenakshi, S.

2012-01-01

A new process for the partitioning of plutonium and uranium during the reprocessing of spent fuel discharged from fast reactor was optimised using hydroxyurea (HU) as a reductant. Stoichiometric ratio of HU required for the reduction of Pu(IV) was studied. The effect of concentration of uranium, plutonium and acidity on the distribution ratio (Kd) of Pu in the presence of HU was studied. The effect of HU in further purification of Pu such as solvent extraction and precipitation of plutonium as oxalate was also studied. The results of the study indicate that Pu and U can be separated from each other using HU as reductant. (author)

Plutonium controversy

International Nuclear Information System (INIS)

Richmond, C.R.

1980-01-01

The toxicity of plutonium is discussed, particularly in relation to controversies surrounding the setting of radiation protection standards. The sources, amounts of, and exposure pathways of plutonium are given and the public risk estimated

Perspective on plutonium

International Nuclear Information System (INIS)

Sun, L.S.

1993-01-01

This paper is intended as a brief overview on the element plutonium. Plutonium is the first primarily man-made element to play a significant role not only in technological development, but also in the economic growth of many countries. The importance of plutonium centers around its enormous energy making it ideal for wide-scale use in reactors, while the nuclear industry continues to work toward improving safety and efficiency of plutonium as a reactor fuel politicians and the public still debate over the safety and benefits of nuclear power. (30 refs.)

Radiolysis of polytetrafluoroethylene

International Nuclear Information System (INIS)

Ferreira, Max Passos; Ferreira, Roberta Viana; Verly, Rodrigo Moreira

2007-01-01

Polytetrafluoroethylene is a linear polymer with structure: -[-CF 2 -CF 2 -] n -. Due to its singular properties, it is ideal for use at high temperatures and in chemically aggressive environments. It is extremely sensitive to ionizing radiation and is quickly degraded. PTFE radiolysis has been extensively studied. However, despite the many published papers, its degradation mechanism remains much uncertain. The degradation of polytetrafluoroethylene by γ irradiation yields perfluorinated carboxylic acids, olefin mixtures, and paraffins with different molecular weights. This process is a new alternative for the synthesis of aliphatic perfluorinated compounds used as intermediates for obtaining special products such as fluoro surfactants, electrical materials, special products for the textile industry, etc. PTFE scraps were irradiated with a uniform source of 60 Co gamma rays in oxygen atmosphere with a dose of 3 MGy. The radiolysis of PTFE yielded a water soluble material (probably fluorinated hydrocarbons with low molecular weight and main chains with 10-20 carbon atoms) and a water insoluble brittle polymeric material. Spectroscopy analysis in the infrared region of irradiated and non-irradiated PTFE were carried out. X-ray diffractometry pointed to changes in the crystalline structure of PTFE; scanning electron microscopy indicated alterations in samples irradiated under different conditions. Mass spectrometry was also used to identify the compounds formed after sample irradiation. Comparison of irradiated and non-irradiated FTIR spectra showed the formation of bands at 3450 cm -1 , associated with the O-H stretching, and at 1631 cm -1 , associated with the C=O stretching. The bands are characteristic of carboxylic acid, which indicates its formation in irradiated PTFE. (author)

Plutonium controversy

Energy Technology Data Exchange (ETDEWEB)

Richmond, C.R.

1980-01-01

The toxicity of plutonium is discussed, particularly in relation to controversies surrounding the setting of radiation protection standards. The sources, amounts of, and exposure pathways of plutonium are given and the public risk estimated. (ACR)

Risk analysis for a radiolysis gas detonation in an in-pile loop with supercritical water

International Nuclear Information System (INIS)

Zeiger, T.; Raque, M.; Kuznetsov, M.; Redlinger, R.; Schulenberg, T.

2012-01-01

The SCWR (supercritical water reactor) -FQT project is a cooperation between European and Chinese partners aimed to test the fuel SCWR elements under reactor conditions. In the frame of this work the risk of radiolysis gas production in the active range of the test track was assessed. The radiolysis gas could accumulate in an emergency cooling system with stagnating coolant. The ignition of this radiolysis gas could cause pressure peaks that are able to damage the primary coolant circuit. Pressure increase and deformations in case of ignition of accumulated gas were investigated. As piping material the Ti stabilized austenitic steel 08Ch18N10T was assumed, the simulation was performed using the ANSYS code. The results show that pipes without significant wall thickness enhancement cannot withstand the radiolysis gas detonation.

Plutonium, nuclear fuel; Le plutonium, combustible nucleaire

Energy Technology Data Exchange (ETDEWEB)

Grison, E [Commissariat a l' Energie Atomique, Fontenay aux Roses (France). Centre d' Etudes Nucleaires, Saclay

1960-07-01

A review of the physical properties of metallic plutonium, its preparation, and the alloys which it forms with the main nuclear metals. Appreciation of its future as a nuclear fuel. (author) [French] Apercu sur les proprietes physiques du plutonium metallique, sa preparation, ses alliages avec les principaux metaux nucleaires. Consideration sur son avenir en tant que combustible nucleaire. (auteur)

Radiolysis of cyanocobalamin (vitamin B12)

International Nuclear Information System (INIS)

Juanchi, X.; Albarran, G.; Negron-Mendoza, A.

2000-01-01

Research on the radiolysis of vitamins is of considerable interest since these compounds are important nutritional constituents in foods and in dietetic supplements. In spite of these considerations there are few data and very often difficult to compare for the radiolytic behavior of vitamins. In this work we focused our attention on to the study of the radiolysis of cyanocobalamin (vitamin B 12 ) in solid state and in aqueous solutions. The procedure was followed by HPLC and UV-spectroscopy. The results obtained in aqueous solutions showed a dependence of the decomposition as a linear function of the dose. The G of decomposition for a 1x10 -5 M solution was 3.3. In the solid state the vitamin was very stable towards the irradiation in the conditions used in this study with a G=2.1x10 -3 . A study made with Serratia marcescens as a microbiological contaminant showed that at the sterilization dose there is a destruction of the vitamin in aqueous solution. In the solid state the degree of decomposition was 7%. (author)

Fenton-enhanced {gamma}-radiolysis of cyanuric acid

Energy Technology Data Exchange (ETDEWEB)

Varghese, Rani [School of Chemical Sciences, Mahatma Gandhi University, Kottayam 686560, Kerala (India); Aravind, Usha K. [School of Chemical Sciences, Mahatma Gandhi University, Kottayam 686560, Kerala (India); Aravindakumar, Charuvila T. [School of Chemical Sciences, Mahatma Gandhi University, Kottayam 686560, Kerala (India)]. E-mail: CT-Aravindakumar@rocketmail.com

2007-04-02

Degradation of cyanuric acid (OOOT), a stable end product of oxidative decomposition of atrazine, is investigated in a combined field of gamma radiolysis and fenton reaction. The reaction of hydroxyl radical ({center_dot}OH) at pH 6 was carried out by irradiating N{sub 2}O saturated aqueous solutions containing OOOT (1 x 10{sup -3} mol dm{sup -3}), and this resulted only a marginal degradation (20%). However, when the same reaction was carried out in the presence of varying concentrations of ferrous sulfate ((5-10) x 10{sup -5} mol dm{sup -3}), the decay of OOOT has been enhanced to more than 80%. This decay followed a first order kinetics. Nearly similar effects were observed with another triazine derivative, 2,4-dioxohexahydro-1,3,5-triazine (DHT). Two major reaction mechanisms are proposed for the enhanced decay of OOOT. The formation of unstable hydroxyl radical adducts from the reaction of {center_dot}OH which is the result of gamma radiolysis and the Fenton reaction (resulting from the reaction of the added Fe(II) and of the H{sub 2}O{sub 2} from the radiolysis of water), is proposed as the first mechanism. The second mechanism, which is likely the major contributor to degradation, is proposed as the reaction of a nucleophilic adduct, Fe(II)OOH, which could directly react with the electron deficient triazine ring. It is highlighted that such degradation reactions must be explored for the complete degradation of the byproducts of the oxidative decomposition of atrazine.

Fused salt processing of impure plutonium dioxide to high-purity plutonium metal

International Nuclear Information System (INIS)

Mullins, L.J.; Christensen, D.C.; Babcock, B.R.

1982-01-01

A process for converting impure plutonium dioxide (approx. 96% pure) to high-purity plutonium metal (>99.9%) was developed. The process consists of reducing the oxide to an impure plutonium metal intermediate with calcium metal in molten calcium chloride. The impure intermediate metal is cast into an anode and electrorefined to produce high-purity plutonium metal. The oxide reduction step is being done now on a 0.6-kg scale with the resulting yield being >99.5%. The electrorefining is being done on a 4.0-kg scale with the resulting yield being 80 to 85%. The purity of the product, which averages 99.98%, is essentially insensitive to the purity of the feed metal. The yield, however, is directly dependent on the chemical composition of the feed. To date, approximately 250 kg of impure oxide has been converted to pure metal by this processing sequence. The availability of impure plutonium dioxide, together with the need for pure plutonium metal, makes this sequence a valuable plutonium processing tool

Standard test method for plutonium assay by plutonium (III) diode array spectrophotometry

CERN Document Server

American Society for Testing and Materials. Philadelphia

2002-01-01

1.1 This test method describes the determination of total plutonium as plutonium(III) in nitrate and chloride solutions. The technique is applicable to solutions of plutonium dioxide powders and pellets (Test Methods C 697), nuclear grade mixed oxides (Test Methods C 698), plutonium metal (Test Methods C 758), and plutonium nitrate solutions (Test Methods C 759). Solid samples are dissolved using the appropriate dissolution techniques described in Practice C 1168. The use of this technique for other plutonium-bearing materials has been reported (1-5), but final determination of applicability must be made by the user. The applicable concentration range for plutonium sample solutions is 10–200 g Pu/L. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropria...

Geochemical association of plutonium in marine sediments from Palomares (Spain)

International Nuclear Information System (INIS)

Anton, M.P.; Gasco, C.; Sanchez-Cabeza, J.A.; Pujol, L.

1994-01-01

The geochemical association of plutonium in sediments from the marine ecosystem of Palomares has been studied. A sequential leaching technique using selective extractants has been employed to determine the percentages of Pu in the following forms: (a) readily available, (b) exchangeable and adsorbed to specific sites, (c) associated with organic matter, (d) sesquioxides, (e) residual. Plutonium was found to be associated mainly with phases (c), (d) and (e), and therefore, appears to be relatively immobile and not readily available to bottom feeding biota. The effect of different source terms on Pu distribution is also discussed. (orig.)

Analysis of plutonium-239 in occupationally exposed personnel

International Nuclear Information System (INIS)

Hernandez M, H.

2017-10-01

Apart from radiometric techniques, several mass spectrometry (Ms) techniques can be used to evaluate the incorporation of plutonium-239 in occupationally exposed personnel, among which we can consider mass spectrometry with inductively coupled plasma source (Icp-Ms); mass spectrometry with accelerators (AMS); thermal ionization mass spectrometry (TIMS) and secondary ion mass spectrometry (Sims). In this work we evaluated analytical methods to measure isotopes of plutonium-239 in urine samples from occupationally exposed personnel, using alpha spectroscopy (As), magnetic sector mass spectrometry with inductively coupled plasma source (Icp-SFMS) and AMS. The samples were collected during 24 h were acidified with HNO 3 at 5% in v/v. The processes used in the preparation of the samples were: a) co-precipitation, b) acid digestion, c) radiochemical separation and d) electro deposition. The results obtained in terms of minimum detectable activity of plutonium-239 were 0.1 μBq (∼ 0.4 fg per sample), 5.1 μBq (∼ 2 fg per sample), 30.1 μBq (∼ 13 fg per sample) and 0.1 μBq (∼ 51 fg per sample) for AMS, Aridus-Icp-SFMS, Icp, SFMS and As, respectively. On the other hand, samples previously analyzed by As were re-evaluated by Aridus-Icp-SFMS and AMS. The results show that extraction with 60 ml of 5% HNO 3 at 60 degrees Celsius and for 2.5 h is enough to extract 90% of Pu electrodeposited on the planchette. In conclusion, AMS is an ultra-sensitive technique for determining isotope ratios of Pu, especially when is desired to validate a method to measure plutonium-239. Additionally, Icp-SFMS is a rapid analysis technique and can be used as a screening technique in situations of radiological incidents or accidents with Pu in the occupationally exposed personnel. Regarding alpha spectroscopy has been considered as the technique of excellence in the routine analysis to measure plutonium-239 in occupationally exposed personnel, due to the low cost. Finally, Icp-SFMS and AMS

Rapid and automated determination of plutonium and neptunium in environmental samples

International Nuclear Information System (INIS)

Qiao, J.

2011-03-01

This thesis presents improved analytical methods for rapid and automated determination of plutonium and neptunium in environmental samples using sequential injection (SI) based chromatography and inductively coupled plasma mass spectrometry (ICP-MS). The progress of methodology development in this work consists of 5 subjects stated as follows: 1) Development and optimization of an SI-anion exchange chromatographic method for rapid determination of plutonium in environmental samples in combination of inductively coupled plasma mass spectrometry detection (Paper II); (2) Methodology development and optimization for rapid determination of plutonium in environmental samples using SI-extraction chromatography prior to inductively coupled plasma mass spectrometry (Paper III); (3) Development of an SI-chromatographic method for simultaneous determination of plutonium and neptunium in environmental samples (Paper IV); (4) Investigation of the suitability and applicability of 242 Pu as a tracer for rapid neptunium determination using anion exchange chromatography in an SI-network coupled with inductively coupled plasma mass spectrometry (Paper V); (5) Exploration of macro-porous anion exchange chromatography for rapid and simultaneous determination of plutonium and neptunium within an SI system (Paper VI). The results demonstrate that the developed methods in this study are reliable and efficient for accurate assays of trace levels of plutonium and neptunium as demanded in different situations including environmental risk monitoring and assessment, emergency preparedness and surveillance of contaminated areas. (Author)

Rapid and automated determination of plutonium and neptunium in environmental samples

Energy Technology Data Exchange (ETDEWEB)

Qiao, J.

2011-03-15

This thesis presents improved analytical methods for rapid and automated determination of plutonium and neptunium in environmental samples using sequential injection (SI) based chromatography and inductively coupled plasma mass spectrometry (ICP-MS). The progress of methodology development in this work consists of 5 subjects stated as follows: 1) Development and optimization of an SI-anion exchange chromatographic method for rapid determination of plutonium in environmental samples in combination of inductively coupled plasma mass spectrometry detection (Paper II); (2) Methodology development and optimization for rapid determination of plutonium in environmental samples using SI-extraction chromatography prior to inductively coupled plasma mass spectrometry (Paper III); (3) Development of an SI-chromatographic method for simultaneous determination of plutonium and neptunium in environmental samples (Paper IV); (4) Investigation of the suitability and applicability of 242Pu as a tracer for rapid neptunium determination using anion exchange chromatography in an SI-network coupled with inductively coupled plasma mass spectrometry (Paper V); (5) Exploration of macro-porous anion exchange chromatography for rapid and simultaneous determination of plutonium and neptunium within an SI system (Paper VI). The results demonstrate that the developed methods in this study are reliable and efficient for accurate assays of trace levels of plutonium and neptunium as demanded in different situations including environmental risk monitoring and assessment, emergency preparedness and surveillance of contaminated areas. (Author)

Low-level detection and quantification of Plutonium(III, IV, V,and VI) using a liquid core waveguide

International Nuclear Information System (INIS)

Wilson, Richard E.; Hu, Yung-Jin; Nitsche, Heino

2003-01-01

Understanding the aqueous chemistry of plutonium, in particular in environmental conditions, is often complicated by plutonium's complex redox chemistry. Because plutonium possesses four oxidation states, all of which can coexist in solution, a reliable method for the identification of these oxidation states is needed. The identification of plutonium oxidation states at low levels in aqueous solution is often accomplished through an indirect determination using series of liquid-liquid extraction procedures using oxidation state specific reagents such as HDEHP and TTA. While these methods, coupled with radioactive counting techniques provide superior limits of detection they may influence the plutonium redox equilibrium, are time consuming, waste intensive and costly. Other analytical methods such as mass spectrometry and radioactive counting as stand alone methods provide excellent detection limits but lack the ability to discriminate between the oxidation states of the plutonium ions in solution

Application of chemiluminescence to the study of alpha, beta and gamma radiolysis of water

International Nuclear Information System (INIS)

Broudic, V.; Muzeau, B.; Jegou, C.; Bonnal, M.; Gavazzi, A.; Marques, C.

2004-01-01

In the frame of the French research program on the long-term behavior of spent nuclear fuel, experiments are conducted in ATALANTE to develop and validate models of spent fuel evolution in contact with an aqueous phase. One of the mechanisms that may govern intermediate or long-term alteration of the spent fuel matrix in a repository is the oxidizing dissolution by radiolysis products of water. Leaching experiments in de-aerated media requires the analysis of hydrogen peroxide, as a major product of water radiolysis, down to 10 -8 mol.L -1 . This work presents the results obtained using the chemiluminescence reaction of iso-luminol with H 2 O 2 , catalyzed by micro-peroxidase. Depending on the samples used, different types of radiolytic processes were studied: α radiolysis of water when leaching UO 2 pellets doped with alpha emitters, or γ radiolysis of water when leaching the same samples or spent fuel in a gamma field. Influences of operating conditions on the analytical results are discussed. (authors)

Water Solubility of Plutonium and Uranium Compounds and Residues at TA-55

International Nuclear Information System (INIS)

Reilly, Sean Douglas; Smith, Paul Herrick; Jarvinen, Gordon D.; Prochnow, David Adrian; Schulte, Louis D.; DeBurgomaster, Paul Christopher; Fife, Keith William; Rubin, Jim; Worl, Laura Ann

2016-01-01

Understanding the water solubility of plutonium and uranium compounds and residues at TA-55 is necessary to provide a technical basis for appropriate criticality safety, safety basis and accountability controls. Individual compound solubility was determined using published solubility data and solution thermodynamic modeling. Residue solubility was estimated using a combination of published technical reports and process knowledge of constituent compounds. The scope of materials considered includes all compounds and residues at TA-55 as of March 2016 that contain Pu-239 or U-235 where any single item in the facility has more than 500 g of nuclear material. This analysis indicates that the following materials are not appreciably soluble in water: plutonium dioxide (IDC=C21), plutonium phosphate (IDC=C66), plutonium tetrafluoride (IDC=C80), plutonium filter residue (IDC=R26), plutonium hydroxide precipitate (IDC=R41), plutonium DOR salt (IDC=R42), plutonium incinerator ash (IDC=R47), uranium carbide (IDC=C13), uranium dioxide (IDC=C21), U 3 O 8 (IDC=C88), and uranium filter residue (IDC=R26). This analysis also indicates that the following materials are soluble in water: plutonium chloride (IDC=C19) and uranium nitrate (IDC=C52). Equilibrium calculations suggest that PuOCl is water soluble under certain conditions, but some plutonium processing reports indicate that it is insoluble when present in electrorefining residues (R65). Plutonium molten salt extraction residues (IDC=R83) contain significant quantities of PuCl 3 , and are expected to be soluble in water. The solubility of the following plutonium residues is indeterminate due to conflicting reports, insufficient process knowledge or process-dependent composition: calcium salt (IDC=R09), electrorefining salt (IDC=R65), salt (IDC=R71), silica (IDC=R73) and sweepings/screenings (IDC=R78). Solution thermodynamic modeling also indicates that fire suppression water buffered with a commercially-available phosphate

Water Solubility of Plutonium and Uranium Compounds and Residues at TA-55

Energy Technology Data Exchange (ETDEWEB)

Reilly, Sean Douglas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States; Smith, Paul Herrick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States; Jarvinen, Gordon D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States; Prochnow, David Adrian [Los Alamos National Lab. (LANL), Los Alamos, NM (United States; Schulte, Louis D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States; DeBurgomaster, Paul Christopher [Los Alamos National Lab. (LANL), Los Alamos, NM (United States; Fife, Keith William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States; Rubin, Jim [Los Alamos National Lab. (LANL), Los Alamos, NM (United States; Worl, Laura Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States

2016-06-13

Understanding the water solubility of plutonium and uranium compounds and residues at TA-55 is necessary to provide a technical basis for appropriate criticality safety, safety basis and accountability controls. Individual compound solubility was determined using published solubility data and solution thermodynamic modeling. Residue solubility was estimated using a combination of published technical reports and process knowledge of constituent compounds. The scope of materials considered includes all compounds and residues at TA-55 as of March 2016 that contain Pu-239 or U-235 where any single item in the facility has more than 500 g of nuclear material. This analysis indicates that the following materials are not appreciably soluble in water: plutonium dioxide (IDC=C21), plutonium phosphate (IDC=C66), plutonium tetrafluoride (IDC=C80), plutonium filter residue (IDC=R26), plutonium hydroxide precipitate (IDC=R41), plutonium DOR salt (IDC=R42), plutonium incinerator ash (IDC=R47), uranium carbide (IDC=C13), uranium dioxide (IDC=C21), U₃O₈ (IDC=C88), and uranium filter residue (IDC=R26). This analysis also indicates that the following materials are soluble in water: plutonium chloride (IDC=C19) and uranium nitrate (IDC=C52). Equilibrium calculations suggest that PuOCl is water soluble under certain conditions, but some plutonium processing reports indicate that it is insoluble when present in electrorefining residues (R65). Plutonium molten salt extraction residues (IDC=R83) contain significant quantities of PuCl₃, and are expected to be soluble in water. The solubility of the following plutonium residues is indeterminate due to conflicting reports, insufficient process knowledge or process-dependent composition: calcium salt (IDC=R09), electrorefining salt (IDC=R65), salt (IDC=R71), silica (IDC=R73) and sweepings/screenings (IDC=R78). Solution thermodynamic modeling also indicates that fire suppression water buffered with a

Plutonium storage criteria

Energy Technology Data Exchange (ETDEWEB)

Chung, D. [Scientech, Inc., Germantown, MD (United States); Ascanio, X. [Dept. of Energy, Germantown, MD (United States)

1996-05-01

The Department of Energy has issued a technical standard for long-term (>50 years) storage and will soon issue a criteria document for interim (<20 years) storage of plutonium materials. The long-term technical standard, {open_quotes}Criteria for Safe Storage of Plutonium Metals and Oxides,{close_quotes} addresses the requirements for storing metals and oxides with greater than 50 wt % plutonium. It calls for a standardized package that meets both off-site transportation requirements, as well as remote handling requirements from future storage facilities. The interim criteria document, {open_quotes}Criteria for Interim Safe Storage of Plutonium-Bearing Solid Materials{close_quotes}, addresses requirements for storing materials with less than 50 wt% plutonium. The interim criteria document assumes the materials will be stored on existing sites, and existing facilities and equipment will be used for repackaging to improve the margin of safety.

Preparation and application of potassium and sodium titanate for removal of plutonium from basic solution

International Nuclear Information System (INIS)

Patil, Prashant; Pathak, Sachin S.; Pius, I.C.; Mukerjee, S.K.

2014-01-01

In PUREX process, after extraction and stripping of uranium and plutonium, the extractant, tributyl phosphate is usually washed with sodium carbonate solution before reuse for the removal of radiolytic/hydrolytic degradation products of TBP and small amounts of HNO 3 , uranium and plutonium goes into aqueous phase during carbonate washings. Partial neutralization of carbonate by the acid converts it to bicarbonate. Removal of plutonium from such sodium carbonate/bicarbonate streams facilitates their disposal. In the present work, studies were carried out to prepare inorganic ion-exchangers such as potassium and sodium titanates for their application as ion-exchange material. It is essential to prepare these materials in granular form to obtain good liquid flow property for ion exchange column operations, however, it is also important that the final product is having good surface area and porosity so that they may exhibit good ion exchange capacity

The plutonium: brief presentation of its nuclear, physical and chemical properties

International Nuclear Information System (INIS)

Madic, C.

1993-01-01

In this text we give a brief presentation of the nuclear properties (isotopes, isotopic composition of spent fuels, decay), of the physical properties (phase diagrams, alloys) and of the chemical properties (complexes, solvent extraction) of the plutonium

Toxicology of plutonium

International Nuclear Information System (INIS)

Bair, W.J.

1974-01-01

Data are reviewed from studies on the toxicity of Pu in experimental animals. Of the several plutonium isotopes, only 238 Pu and 239 Pu have been studied well. Sufficient results have been obtained to show that the behavior of 238 Pu in biological systems and the resulting biological effects cannot be precisely predicted from studies of 239 Pu. This probably applies also to other radiologically important plutonium isotopes which have half-lives ranging from 45 days to 10 7 years and decay by β-emission, electron capture, and spontaneous fission, as well as by emission of α-particles. All the biological effects of plutonium described in this review are attributed to alpha-particle radiation emitted by the plutonium. However, since plutonium is a chemically active heavy metal, one cannot ignore the possibility of chemical toxicity of the low-specific-activity isotopes, 239 Pu, 242 Pu, and 244 Pu. The preponderance of our knowledge of plutonium toxicology has come from short-term studies of relatively high dosage levels in several animal species. The consequences of high-level internal exposures can be predicted with confidence in experimental animals and probably also in man. However, considering the care with which plutonium is handled in the nuclear industry, a high-level contamination event is unlikely. Considerably less is known about the long-term effects of low levels of contamination. (250 references) (U.S.)

Radical Cations and Acid Protection during Radiolysis

Energy Technology Data Exchange (ETDEWEB)

Mincher, Bruce J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zarzana, Christopher A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mezyk, Stephen P. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2016-09-09

Ligand molecules for used nuclear fuel separation schemes are exposed to high radiation fields and high concentrations of acid. Thus, an understanding of the complex interactions between extraction ligands, diluent, and acid is critical to understanding the performance of a separation process. The diglycolamides are ligands with important structural similarities to CMPO; however, previous work has shown that their radiolytic degradation has important mechanistic differences from CMPO. The DGAs do not enjoy radioprotection by HNO3 and the kinetics of DGA radiolytic degradation are different. CMPO degrades with pseudo-zero-order kinetics in linear fashion with absorbed dose while the DGAs degrade in pseudo-first-order, exponential fashion. This suggests that the DGAs degrade by simple reaction with some product of direct diluent radiolysis, while CMPO degradation is probably multi-step, with a slow step that is not dependent on the CMPO concentration, and mitigated by HNO₃. It is thus believed that radio-protection and the zero-order radiolytic degradation kinetics are related, and that these phenomena are a function of either the formation of strong acid complexes with CMPO and/or to the presence of the CMPO phenyl ring. Experiments to test both these hypotheses have been designed and partially conducted. This report summarizes findings related to these phenomena for FY16, in satisfaction of milestone M3FT-16IN030104053. It also reports continued kinetic measurements for the reactions of the dodecane radical cation with solvent extraction ligands.

Radical Cations and Acid Protection during Radiolysis

International Nuclear Information System (INIS)

Mincher, Bruce J.; Zarzana, Christopher A.; Mezyk, Stephen P.

2016-01-01

Ligand molecules for used nuclear fuel separation schemes are exposed to high radiation fields and high concentrations of acid. Thus, an understanding of the complex interactions between extraction ligands, diluent, and acid is critical to understanding the performance of a separation process. The diglycolamides are ligands with important structural similarities to CMPO; however, previous work has shown that their radiolytic degradation has important mechanistic differences from CMPO. The DGAs do not enjoy radioprotection by HNO3 and the kinetics of DGA radiolytic degradation are different. CMPO degrades with pseudo-zero-order kinetics in linear fashion with absorbed dose while the DGAs degrade in pseudo-first-order, exponential fashion. This suggests that the DGAs degrade by simple reaction with some product of direct diluent radiolysis, while CMPO degradation is probably multi-step, with a slow step that is not dependent on the CMPO concentration, and mitigated by HNO 3 . It is thus believed that radio-protection and the zero-order radiolytic degradation kinetics are related, and that these phenomena are a function of either the formation of strong acid complexes with CMPO and/or to the presence of the CMPO phenyl ring. Experiments to test both these hypotheses have been designed and partially conducted. This report summarizes findings related to these phenomena for FY16, in satisfaction of milestone M3FT-16IN030104053. It also reports continued kinetic measurements for the reactions of the dodecane radical cation with solvent extraction ligands.

Radiation chemistry in solvent extraction: FY2010 Research

International Nuclear Information System (INIS)

Mincher, Bruce J.; Martin, Leigh R.; Mezyk, Stephen P.

2010-01-01

This report summarizes work accomplished under the Fuel Cycle Research and Development (FCR and D) program in the area of radiation chemistry during FY 2010. The tasks assigned during FY 2010 included: (1) Development of techniques to measure free radical reaction kinetics in the organic phase. (2) Initiation of an alpha-radiolysis program; (3) Initiation of an effort to understand dose rate effects in radiation chemistry; (4) Continued work to characterize TALSPEAK radiation chemistry Progress made on each of these tasks is reported here. Briefly, a method was developed and used to measure the kinetics of the reactions of the NO3 radical with solvent extraction ligands in organic solution, and the method to measure OH radical reactions under the same conditions has been designed. Rate constants for the CMPO and DMDOHEMA reaction with NO3 radical in organic solution are reported. Alpha-radiolysis was initiated on samples of DMDOHEMA in alkane solution using He ion beam irradiation and 211At isotope irradiation. The samples are currently being analyzed for comparison to DMDOHEMA ?-irradiations using a custom-developed mass spectrometric method. Results are also reported for the radiolytic generation of nitrous acid, in ?-irradiated nitric acid. It is shown that the yield of nitrous acid is unaffected by an order-of-magnitude change in dose rate. Finally, recent results for TALSPEAK radiolysis are reported, summarizing the effects on solvent extraction efficiency due to HDEHP irradiation, and the stable products of lactic acid and DTPA irradiation. In addition, results representing increased scope are presented for the radiation chemistry program. These include an investigation of the effect of metal complexation on radical reaction kinetics using DTPA as an example, and the production of a manuscript reporting the mechanism of Cs-7SB radiolysis. The Cs-7SB work takes advantage of recent results from a current LDRD program to understand the fundamental chemistry of

Contribution to the modelization of liquid-liquid extraction systems. Application to metallic nitrate extraction by TBP in nitric medium

International Nuclear Information System (INIS)

Ly, J.

1984-10-01

The validity of theoretical expression for activity coefficients, in concentrated aqueous solution, proposed by Mikulin-Stokes-Robinson and Ryazanov-Vdovenko is confirmed by numerous tests. This allows a better control of the reactivity of chemicals in the extraction system: nitric aqueous solution-TBP organic solution used in nuclear hydrometallurgy. A reliable methodology is proposed for the study of metal extraction mechanism. Application to palladium (II) evidences extracted species in the organic phase. Influence of degradation product from extractant radiolysis on the behavior of this metallic element is effected. 187 refs [fr

Reaction mechanisms in the radiolysis of peptides, polypeptides and proteins

International Nuclear Information System (INIS)

Garrison, W.M.

1985-01-01

The purpose of this review is to bring together and to correlate the wide variety of experimental studies that provide information on the reaction products and reaction mechanisms involved in the radiolysis of peptides, polypeptides and proteins (including chromosomal proteins) in both aqueous and solid-state systems. The comparative radiation chemistry of these systems is developed in terms of specific reactions of the peptide main-chain and the aliphatic, aromatic-unsaturated and sulfur-containing side-chains. Information obtained with the various experimental techniques of product analysis, competition kinetics, spin-trapping, pulse radiolysis and ESR spectroscopy is included. 147 refs

Reaction mechanisms in the radiolysis of peptides, polypeptides and proteins

Energy Technology Data Exchange (ETDEWEB)

Garrison, W.M.

1985-01-01

The purpose of this review is to bring together and to correlate the wide variety of experimental studies that provide information on the reaction products and reaction mechanisms involved in the radiolysis of peptides, polypeptides and proteins (including chromosomal proteins) in both aqueous and solid-state systems. The comparative radiation chemistry of these systems is developed in terms of specific reactions of the peptide main-chain and the aliphatic, aromatic-unsaturated and sulfur-containing side-chains. Information obtained with the various experimental techniques of product analysis, competition kinetics, spin-trapping, pulse radiolysis and ESR spectroscopy is included. 147 refs.

Electron paramagnetic resonance study of radicals formed by radiolysis at 77 K of nitroalkanes and of their solutions in organic glasses. Chromatography analysis of radiolysis products of nitromethane in ethanol solution in a vitreous medium

International Nuclear Information System (INIS)

Rosilio, C.

1969-01-01

With a view to explaining the formation of the final products resulting from the photolysis and the radiolysis of nitro-alkanes, we have attempted to identify the paramagnetic species formed as intermediates during the radiolysis. Our work has covered the structure and the reactivity of the radicals formed by 7 irradiation of the nitrogen containing derivatives at 77 K, and on the mechanism of formation and of disappearance of these radicals in the various matrices used. The radicals resulting from the removal of a hydrogen atom in the α position of the NO 2 group, and the radicals resulting from addition reactions on the nitrogen group characterized by an unpaired electron on the nitrogen have been identified, either during the radiolysis of pure nitroalkanes, or during the radiolysis of nitro-alkanes in solution in organic glasses at 77 K. A study has been made of the conformation and the movements of radicals in the matrices, and the mechanism of formation of the observed radicals produced generally by the capture by the nitro-alkanes of primary radiolysis species. The nitro-alkanes in ethanol solution can behave as traps both for electrons and for free radicals. The study of the radiolysis of nitro-alkanes in solution in a polar ethanol glass has been completed with chemical analyses on the final radiolysis products; it has been possible to deduce the capture efficiency of trapped electrons and of free radicals by nitro-alkanes in ethanol. For this we have determined the radio-chemical yields of hydrogen, acetaldehyde and glycol as a function of the capture agent concentration, for the nitro-methane-ethanol system. A mechanism for the disappearance of the observed radicals is proposed. (author) [fr

Cycle downstream: the plutonium question; Aval du cycle la question du plutonium

Energy Technology Data Exchange (ETDEWEB)

Zask, G [Electricite de France, EDF/DAC, 75 - Paris (France); Rome, M [Electricite de France, EDF, Service Etudes et Projets Thermiques et Nucleaires, 92 - Courbevoie (France); Delpech, M [CEA Cadarache, Dept. d' Etudes des Reacteurs/SPRC, 13 - Saint-Paul-lez-Durance (France); and others

1998-06-29

This day, organized by the SFEN, took place at Paris the 4 june 1998. Nine papers were presented. They take stock on the plutonium physics and its utilization as a nuclear fuel. This day tried to bring information to answer the following questions: do people have to keep the plutonium in the UOX fuel or in the MOX fuel in order to use it for future fast reactors? Do people have to continue obstinately the plutonium reprocessing in the MOX for the PWR type reactors? Will it be realized a underground disposal? Can it be technically developed plutonium incinerators and is it economically interesting? The plutonium physics, the experimental programs and the possible solutions are presented. (A.L.B.)

Pulse radiolysis of anthraquinone dye aqueous solution

International Nuclear Information System (INIS)

Perkowski, J.; Gebicki, J.L.; Lubis, R.; Mayer, J.

1988-01-01

Pulse radiolysis of argon flushed aqueous solutions of 10 -5 -10 -4 mol dm -3 anthraquinone dye (C.I. Acid Blue 62) gives rise to the transients originated from the reactions of e - aq , OH and H. The rate constants of these reactions are determined. (author)

Radiolysis of DNA-protein complexes

Energy Technology Data Exchange (ETDEWEB)

Begusova, Marie [Department of Radiation Dosimetry, Nuclear Physics Institute, Na Truhlarce 39/64, CZ-18086, Prague 8 (Czech Republic)]. E-mail: begusova@ujf.cas.cz; Gillard, Nathalie [Centre de Biophysique Moleculaire, CNRS, rue Charles-Sadron, F-45071 Orleans Cedex 2 (France); Sy, Denise [Centre de Biophysique Moleculaire, CNRS, rue Charles-Sadron, F-45071 Orleans Cedex 2 (France); Castaing, Bertrand [Centre de Biophysique Moleculaire, CNRS, rue Charles-Sadron, F-45071 Orleans Cedex 2 (France); Charlier, Michel [Centre de Biophysique Moleculaire, CNRS, rue Charles-Sadron, F-45071 Orleans Cedex 2 (France); Spotheim-Maurizot, Melanie [Centre de Biophysique Moleculaire, CNRS, rue Charles-Sadron, F-45071 Orleans Cedex 2 (France)

2005-02-01

We discuss here modifications of DNA and protein radiolysis due to the interaction of these two partners in specific complexes. Experimental patterns of frank strand breaks (FSB) and alkali revealed breaks (ARB) obtained for DNA lac operator bound to the lac repressor and for a DNA containing an abasic site analog bound to the formamidopyrimidine-DNA glycosylase are reported. Experimental data are compared to predicted damage distribution obtained using the theoretical model RADACK.

Radiolysis of DNA-protein complexes

International Nuclear Information System (INIS)

Begusova, Marie; Gillard, Nathalie; Sy, Denise; Castaing, Bertrand; Charlier, Michel; Spotheim-Maurizot, Melanie

2005-01-01

We discuss here modifications of DNA and protein radiolysis due to the interaction of these two partners in specific complexes. Experimental patterns of frank strand breaks (FSB) and alkali revealed breaks (ARB) obtained for DNA lac operator bound to the lac repressor and for a DNA containing an abasic site analog bound to the formamidopyrimidine-DNA glycosylase are reported. Experimental data are compared to predicted damage distribution obtained using the theoretical model RADACK

Plutonium hydrolysis and the double double-point

International Nuclear Information System (INIS)

Silver, G.L.

2011-01-01

There is uncertainty about the numerical value of the first hydrolysis constant of the tetravalent plutonium ion. A new method for discriminating between the claims is illustrated. It suggests the traditional estimates of that constant are closer to its true value than a singular result based on a few solvent-extraction experiments. A previously unnoticed multiple point in aqueous Pu chemistry is illustrated. (author)

Empirical equations of the solvent extraction of the energetic inputs, uranium and plutonium, calculated by using the program Microsoft Excel

International Nuclear Information System (INIS)

Bento, Dercio Lopes

2006-01-01

PUREX is one of the purification process for irradiated nuclear fuel. In the flowchart the program uses various uranium and plutonium extraction phases by using organic solvent contained in the aqueous phase obtained in the dissolution of the fuel element. A posterior extraction U and Pu are changed to the aqueous phase. So it is fundamental to know the distribution coefficient (dS), at the temperature (tc), of the substances among the two immiscible phases, for better calculation the suitable flowchart. A mathematical model was elaborated based on experimental data, for the calculation of the dS and applied to a referential band of substance concentrations in the aqueous phase (xS) and organic (yS). By using the program Excel, we personalized the empirical equations calculated by the root mean square. The relative deviation, among the calculated values and the experimental ones are the standards

A review of the radiolysis of methane

International Nuclear Information System (INIS)

Norfolk, D.J.

1975-08-01

The review had three objectives: to determine the yields of the primary products and to describe the sequence of reactions in which they take part; to ascertain the effect on these reactions of changes in the physical state of the methane and the quantum energy of the radiation, and of the presence of chemically inert sensitisers; and to identify the situation most similar to the adsorbed phase radiolysis of methane on alumina, and so to predict the likely radiolytic reactions in this system. The main primary product yields in methane gas under γ-irradiation are estimated to be G(CH 4 +) approximately 1.75, G(CH 3 +) approximately 1.46, G(CH 3 ) approximately 1.4 and G(CH 2 ) approximately 1.0. The situation most similar to adsorbed phase radiolysis is inert gas sensitised photolysis at energies below 12.6eV. In this system the major primary process is homolytic dissociation of methane to CH 3 +H. (author)

Determination of uranium and plutonium in urine of people working with regenerated uranium

International Nuclear Information System (INIS)

Golutvina, M.M.; Ryzhova, E.A.

1987-01-01

Method of determining uranium and plutonium content in urine with their combined presence up to α-activity ratio Pu:U=1:100 is developed. The method is based on extraction chromatographic separation of nuclides using trimethyloctylammonium nitrate and their subsequent α-spectrometric determination. The coefficient of plutonium purification from uranium makes up 750. Chemical yield of Pu is 72±6%, U-76±8%. The method sensitivity is 0.2 decompositions per minute for a sample

Nuclear magnetic resonance in pulse radiolysis. Chemically induced dynamic nuclear polarization

International Nuclear Information System (INIS)

Trifunac, A.D.; Johnson, K.W.; Lowers, R.H.

1976-01-01

Nuclear magnetic resonance and chemically induced dynamic nuclear polarization (CIDNP) were applied to the study of pulse radiolysis. Samples were irradiated with a 3-MeV electron beam from the Argonne Van de Graaff accelerator in an EPR magnet (approximately 4000 G) which had axial holes for beam access. A fast flow system transferred the irradiated solution to the rotating 5-mm NMR sample tube. The NMR spectra of mixtures of sodium acetate and methanol were presented to demonstrate the features of the CIDNP in pulse radiolysis

Plutonium re-cycle in HTR

Energy Technology Data Exchange (ETDEWEB)

Desoisa, J. A.

1974-03-15

The study of plutonium cycles in HTRs using reprocessed plutonium from Magnox and AGR fuel cycles has shown that full core plutonium/uranium loadings are in general not feasible, burn-up is limited due the need for lower loadings of plutonium to meet reload core reactivity limits, on-line refueling is not practicable due to the need for higher burnable poison loadings, and low conversion rates in the plutonium-uranium cycles cannot be mitigated by axial loading schemes so that fissile make-up is needed if HTR plutonium recycle is desired.

PLUTONIUM-ZIRCONIUM ALLOYS

Science.gov (United States)

Schonfeld, F.W.; Waber, J.T.

1960-08-30

A series of nuclear reactor fuel alloys consisting of from about 5 to about 50 at.% zirconium (or higher zirconium alloys such as Zircaloy), balance plutonium, and having the structural composition of a plutonium are described. Zirconium is a satisfactory diluent because it alloys readily with plutonium and has desirable nuclear properties. Additional advantages are corrosion resistance, excellent fabrication propenties, an isotropie structure, and initial softness.

Recombination rates of hydrogen and oxygen over pure and impure plutonium oxides

International Nuclear Information System (INIS)

Morales, L.

1999-01-01

Long-term, safe storage of excess plutonium-bearing materials is required until stabilization and disposal methods are implemented or defined. The US Department of Energy (DOE) has established a plan to address the stabilization, packing, and storage of plutonium-bearing materials from around the complex. The DOE's standard method, DOE-STD-3013-96 and its proposed revision, for stabilizing pure and impure actinide materials is by calcination in air followed by sealing the material in welded stainless steel containers. The 3013 standard contains and equation that predicts the total pressure buildup in the can over the anticipated storage time of 50 yr. This equation was meant to model a worst-case scenario to ensure that pressures would not exceed the strength of the container at the end of 50 yr. As a result, concerns about pressure generation in the storage cans, both absolute values and rates, have been raised with regard to rupture and dispersal of nuclear materials. Similar issues have been raised about the transportation of these materials around the complex. The purpose of this work is to provide a stronger technical basis for the 3013 standard by measuring the recombination rates of hydrogen/oxygen mixtures in contact with pure and impure plutonium oxides. The goal of these experiments was to determine whether the rate of recombination is faster than the rate of water radiolysis under controlled conditions. This was accomplished by using a calibrated pressure-volume-temperature apparatus to measure the recombination rates in a fixed volume as the gas mixture was brought into contact with oxide powders whose temperatures ranged from 50 to 300 C. These conditions were selected in order to bracket the temperature conditions expected in a typical storage can. In addition, a 2% H 2 /air mixture encompasses scenarios in which the cans are sealed in air, and over time various amounts of hydrogen are formed

Optimization and plutonium equilibrium

International Nuclear Information System (INIS)

Silver, G.L.

1976-01-01

The sequential simplex method has been used to estimate the extent of disproportionation of tetravalent plutonium in dilute acid. A method for simulating potentiometric titrations is proposed, and this method suggests that the stoichiometric end point and the inflection point may not always correspond in the potentiometric titration of plutonium. A possible characteristic equation for the nitrite-plutonium reaction is illustrated, and the method of proportional equations is extended to the iron-plutonium reaction

Weapons-grade plutonium dispositioning. Volume 2: Comparison of plutonium disposition options

International Nuclear Information System (INIS)

Brownson, D.A.; Hanson, D.J.; Blackman, H.S.

1993-06-01

The Secretary of Energy requested the National Academy of Sciences (NAS) Committee on International Security and Arms Control to evaluate disposition options for weapons-grade plutonium. The Idaho National Engineering Laboratory (INEL) offered to assist the NAS in this evaluation by investigating the technical aspects of the disposition options and their capability for achieving plutonium annihilation levels greater than 90%. This report was prepared for the NAS to document the gathered information and results from the requested option evaluations. Evaluations were performed for 12 plutonium disposition options involving five reactor and one accelerator-based systems. Each option was evaluated in four technical areas: (1) fuel status, (2) reactor or accelerator-based system status, (3) waste-processing status, and (4) waste disposal status. Based on these evaluations, each concept was rated on its operational capability and time to deployment. A third rating category of option costs could not be performed because of the unavailability of adequate information from the concept sponsors. The four options achieving the highest rating, in alphabetical order, are the Advanced Light Water Reactor with plutonium-based ternary fuel, the Advanced Liquid Metal Reactor with plutonium-based fuel, the Advanced Liquid Metal Reactor with uranium-plutonium-based fuel, and the Modular High Temperature Gas-Cooled Reactor with plutonium-based fuel. Of these four options, the Advanced Light Water Reactor and the Modular High Temperature Gas-Cooled Reactor do not propose reprocessing of their irradiated fuel. Time constraints and lack of detailed information did not allow for any further ratings among these four options. The INEL recommends these four options be investigated further to determine the optimum reactor design for plutonium disposition

Weapons-grade plutonium dispositioning. Volume 2: Comparison of plutonium disposition options

Energy Technology Data Exchange (ETDEWEB)

Brownson, D.A.; Hanson, D.J.; Blackman, H.S. [and others

1993-06-01

The Secretary of Energy requested the National Academy of Sciences (NAS) Committee on International Security and Arms Control to evaluate disposition options for weapons-grade plutonium. The Idaho National Engineering Laboratory (INEL) offered to assist the NAS in this evaluation by investigating the technical aspects of the disposition options and their capability for achieving plutonium annihilation levels greater than 90%. This report was prepared for the NAS to document the gathered information and results from the requested option evaluations. Evaluations were performed for 12 plutonium disposition options involving five reactor and one accelerator-based systems. Each option was evaluated in four technical areas: (1) fuel status, (2) reactor or accelerator-based system status, (3) waste-processing status, and (4) waste disposal status. Based on these evaluations, each concept was rated on its operational capability and time to deployment. A third rating category of option costs could not be performed because of the unavailability of adequate information from the concept sponsors. The four options achieving the highest rating, in alphabetical order, are the Advanced Light Water Reactor with plutonium-based ternary fuel, the Advanced Liquid Metal Reactor with plutonium-based fuel, the Advanced Liquid Metal Reactor with uranium-plutonium-based fuel, and the Modular High Temperature Gas-Cooled Reactor with plutonium-based fuel. Of these four options, the Advanced Light Water Reactor and the Modular High Temperature Gas-Cooled Reactor do not propose reprocessing of their irradiated fuel. Time constraints and lack of detailed information did not allow for any further ratings among these four options. The INEL recommends these four options be investigated further to determine the optimum reactor design for plutonium disposition.

Study of the solubility of plutonyl nitrate with a view to its extraction by a solvent; Etude de la solubilite du nitrate de plutonyle en vue de son extraction par solvant

Energy Technology Data Exchange (ETDEWEB)

Vergnaud, G [Commissariat a l' Energie Atomique, Fontenay aux Roses (France). Centre d' Etudes Nucleaires

1965-09-01

The research covers the determination of the partition coefficient of plutonyl nitrate and their application to the industrial treatment of plutonium. The solvent used is a tri-n-butyl phosphate solution diluted to 30 per cent in dodecane. The parameters which have been studied and which can affect the extraction of the plutonyl nitrate are: the plutonyl nitrate concentration; the nitric acid concentration; the uranyl nitrate concentration; the tetravalent plutonium nitrate concentration. The industrial application has been studied using a battery of mixer-separators. The operational conditions are defined in the case of a conventional plutonium separation plant. The results obtained, for a higher plutonyl nitrate concentration than that actually planned, are satisfactory and encouraging as far as the operation is concerned. Only the presence of polymerized tetravalent plutonium can adversely affect the satisfactory extraction of the plutonium. (author) [French] L'etude porte sur les coefficients de partage du nitrate de plutonyle et leur application a l'elaboration industrielle du plutonium. Le solvant utilise est une solution de phosphate de tri-n-butyle, dilue a 30 pour cent dans le dodecane. Les parametres etudies et pouvant influencer l'extraction du nitrate de plutonyle, par ce solvant, sont: concentration du nitrate de plutonyle; concentration de l'acide nitrique; concentration du nitrate d'uranyle; concentration au nitrate de plutonium tetravalent. L'application industrielle est etudiee au moyen d'une batterie de melangeurs-decanteurs. Les conditions operatoires sont definies d'apres un schema classique d'usine de separation de plutonium. Les resultats obtenus, pour une concentration du nitrate de plutonyle superieure a celle reellement prevue, sont satisfaisants et encourageants pour l'exploitation. Seule, la presence de plutonium tetraralent polymerise, peut nuire a une bonne extraction du plutonium. (auteur)

Study of the solubility of plutonyl nitrate with a view to its extraction by a solvent; Etude de la solubilite du nitrate de plutonyle en vue de son extraction par solvant

Energy Technology Data Exchange (ETDEWEB)

Vergnaud, G. [Commissariat a l' Energie Atomique, Fontenay aux Roses (France). Centre d' Etudes Nucleaires

1965-09-01

The research covers the determination of the partition coefficient of plutonyl nitrate and their application to the industrial treatment of plutonium. The solvent used is a tri-n-butyl phosphate solution diluted to 30 per cent in dodecane. The parameters which have been studied and which can affect the extraction of the plutonyl nitrate are: the plutonyl nitrate concentration; the nitric acid concentration; the uranyl nitrate concentration; the tetravalent plutonium nitrate concentration. The industrial application has been studied using a battery of mixer-separators. The operational conditions are defined in the case of a conventional plutonium separation plant. The results obtained, for a higher plutonyl nitrate concentration than that actually planned, are satisfactory and encouraging as far as the operation is concerned. Only the presence of polymerized tetravalent plutonium can adversely affect the satisfactory extraction of the plutonium. (author) [French] L'etude porte sur les coefficients de partage du nitrate de plutonyle et leur application a l'elaboration industrielle du plutonium. Le solvant utilise est une solution de phosphate de tri-n-butyle, dilue a 30 pour cent dans le dodecane. Les parametres etudies et pouvant influencer l'extraction du nitrate de plutonyle, par ce solvant, sont: concentration du nitrate de plutonyle; concentration de l'acide nitrique; concentration du nitrate d'uranyle; concentration au nitrate de plutonium tetravalent. L'application industrielle est etudiee au moyen d'une batterie de melangeurs-decanteurs. Les conditions operatoires sont definies d'apres un schema classique d'usine de separation de plutonium. Les resultats obtenus, pour une concentration du nitrate de plutonyle superieure a celle reellement prevue, sont satisfaisants et encourageants pour l'exploitation. Seule, la presence de plutonium tetraralent polymerise, peut nuire a une bonne extraction du plutonium

Complexation of Plutonium (IV) With Sulfate At Variable Temperatures

International Nuclear Information System (INIS)

Y. Xia; J.I. Friese; D.A. Moore; P.P. Bachelor; L. Rao

2006-01-01

The complexation of plutonium(IV) with sulfate at variable temperatures has been investigated by solvent extraction method. A NaBrO 3 solution was used as holding oxidant to maintain the plutonium(IV) oxidation state throughout the experiments. The distribution ratio of Pu(IV) between the organic and aqueous phases was found to decrease as the concentrations of sulfate were increased. Stability constants of the 1:1 and 1:2 Pu(IV)-HSO 4 - complexes, dominant in the aqueous phase, were calculated from the effect of [HSO 4 - ] on the distribution ratio. The enthalpy and entropy of complexation were calculated from the stability constants at different temperatures using the Van't Hoff equation

Plutonium roundtable discussion

International Nuclear Information System (INIS)

Penneman, R.A.

1982-01-01

The roundtable discussion began with remarks by the chairman who pointed out the complicated nature of plutonium chemistry. Judging from the papers presented at this symposium, he noticed a pattern which indicated to him the result of diminished funding for investigation of basic plutonium chemistry and funding focused on certain problem areas. Dr. G.L. silver pointed to plutonium chemists' erroneous use of a simplified summary equation involving the disproportionation of Pu(EV) and their each of appreciation of alpha coefficients. To his appreciation of alpha coefficients. To his charges, Dr. J.T. Bell spoke in defense of the chemists. This discussion was followed by W.W. Schulz's comments on the need for experimental work to determine solubility data for plutonium in its various oxidation states under geologic repository conditions. Discussion then turned to plutonium pyrachemical process with Dana C. Christensen as the main speaker. This paper presents edited versions of participants' written version

Application of extraction chromatography to the recovery of neptunium, plutonium and americium from an industrial waste

International Nuclear Information System (INIS)

Madic, C.; Kertesz, C.; Sontag, R.; Koehly, G.

1980-01-01

A pilot scale investigation was made to evaluate the possible application of the extraction chromatographic method (LLC) to the partitioning of alpha emitters from liquid wastes containing traces of transuranium elements. A secondary purpose was to obtain pure Am0 2 , which is used to produce alpha, gamma, and neutron sources. The process developed for alpha partitioning consists essentially of the extraction of macro amounts of uranium with 30% TBP in dodecane in mixer-settlers, then coextraction of Np-237, Pu-239, and Am-241 by LLC on a macro column filled with di-n-hexyl-octoxy-methyl-phosphine oxide (POX.11) adsorbed on an inert support. In each run about 200 liters of initial waste are decontaminated of alpha emitters. The loading step is followed by selective elution of americium, neptunium, and plutonium. The americium eluate is then subjected to the following operations: (1) separation of Am from Fe and Cd by LLC on a TBP column and (2) separation of Am from lanthanide traces by LLC on an HD(DiBM)P column after oxidation of Am(III) to Am(VI). The Am in the eluate is subsequently reduced to Am(III) and precipitated as oxalate with oxalic acid. The oxalate is then filtered and calcined to yield pure AmO 2

Possible combustion hazards in 3013 plutonium waste container

International Nuclear Information System (INIS)

Sherman, M.P.

1999-01-01

Are there combustion hazards in plutonium-contaminated waste containers caused by combustible gas generation? Current gas generation models in which the only reaction considered is radiolysis must inevitably predict eventual complete dissociation of any water present into hydrogen and oxygen. Waste prepared for the 3013 container should be less subject to this problem because organic material and most of the absorbed water should have been removed. Depending on the waste form, moisture content, organic content, temperature, and container material, the pressure rise due to gas generation will be bounded by backreactions, recombination of the hydrogen and oxygen, absorption of the oxygen by plutonium oxide, and possibly other chemical reactions. Examination of a variety of food pack waste containers at Los Alamos National Laboratory (LANL) has shown little pressure rise, indeed often subatmospheric pressures. In a few cases large hydrogen concentrations up to 47% mole fraction were observed, but with negligible oxygen content. The only fuel seen in significant quantities was H 2 and, in one case, CO; the only oxidizer seen in significant quantities was O 2 . Considerable work on measuring gas generation is being done at Westinghouse Savannah River Company and LANL. In a mixture of H 2 , O 2 , and other diluent gases, if the hydrogen concentration is below the value at the lean flammability limit, or if the oxygen concentration is below that at the rich flammability limit, a flame will not propagate from an ignition source. Assuming H 2 is the only fuel present in significant quantities, a mixture leaner than the lean limit will get only leaner if mixed with air and is therefore no combustion hazard. However, when a mixture containing large amounts of H 2 is nonflammable because there is insufficient O 2 , there is a hazard. If the mixture should leak into a volume containing O 2 , or the container is opened into the surrounding air, the mixture will pass through the

Radiolysis of simple quaternary ammonium salt components of Amberlite resin

International Nuclear Information System (INIS)

Dhiman, Surajdevprakash B.; LaVerne, Jay A.

2013-01-01

The radiation chemical yields of gaseous products, H 2 and CH 4 , in the radiolysis of dry methylammonium chloride, dimethylammonium chloride, trimethylammonium chloride, tetramethylammonium chloride and benzyl trimethylammonium chloride by γ-rays and 5 MeV helium ions have been investigated. Some of these amines are the different components of the quaternary ammonium resin Amberlite, which is a strongly basic anion exchange resin based on a polystyrene divinylbenzene copolymer. Molecular hydrogen yields with γ-radiolysis range from a high of 4.43 molecules per 100 eV for trimethylammonium chloride to 0.07 and 0.05 molecules per 100 eV for tetramethylammonium chloride and benzyl trimethylammonium chloride, respectively. Yields of methane gas are generally negligible except for trimethylammonium chloride and tetramethylammonium chloride, 0.26 and 0.02 molecules per 100 eV, respectively. Isotopic labeling studies suggest that the first step in H 2 production is the breakage of the N-H bond followed by abstraction of H · atom from the methyl groups. EPR analysis shows the formation of both N and C centered radicals. A comparison is made between the radiolysis of Amberlite and its various components

Investigation of plutonium (4) hydroxoformates

International Nuclear Information System (INIS)

Andryushin, V.G.; Belov, V.A.; Galaktionov, S.V.; Kozhevnikov, P.B.; Matyukha, V.A.; Shmidt, V.S.

1982-01-01

Deposition processes of plutonium (4) hydroxoformates in the system Pu(NO 3 ) 4 -HNO 3 -HCoOH-N6 4 OH-H 2 O have been studied in pH range 0.2-10.7 at total plutonium concentration in the system 100 g/l. It is shown that under the conditions plutonium (4) hydrolysis takes place with the formation of hydroxoformates. A local maximum of plutonium (4) hydroxoformate solubility in the range pH=3.8-4.8, which is evidently conditioned by the formation of soluble formate complex of plutonium in the region, is pointed out. The basic plutonium (4) formates of the composition PuOsub(x)(OH)sub(y)(COOH)sub(4-2x-y)xnHsub(2)O, where 1,3 >=x >= 0.7, 1.7 >= y >= 1.0 and n=1.5-7.0, are singled out, their thermal stability being studied. Density of the crystals and plutonium dioxide, formed during their thermal decomposition, is measured. It is established that for plutonium (4) hydroxoformates common regularities of the influence of salt composition (OH - -, CHOO - - and H 2 O-group numbers in the mulecule) on position of temperature decomposition effects and on the density of compounds, which have been previously found during the study of thorium and plutonium hydroxosalts are observed. It is shown that the density of plutonium dioxide decreases with the increase of hydration and hydrolysis degree of the initial plutonium hydroxoformate

Effects of seawater components on radiolysis of water at elevated temperature

International Nuclear Information System (INIS)

Wada, Yoichi; Tachibana, Masahiko; Ishida, Kazushige; Ota, Nobuyuki; Shigenaka, Naoto; Inagaki, Hiromitsu; Noda, Hiroshi

2014-01-01

Effects of seawater components on radiolysis of water at elevated temperature have been studied with a radiolysis model in order to evaluate influence on integrity of materials used in an ABWR. In 2011, seawater flowed into a wide part of the nuclear power plant system of the Hamaoka Nuclear Power Station Reactor No. 5 owned by Chubu Electric Power Co., Inc. after condenser tubes broke during the plant shutdown operation. The reactor water temperature was 250°C and its maximum Cl − concentration was ca. 450 ppm when seawater was mixed with reactor water. In order to clarify effects of the sea water components on radiolysis of water at elevated temperature, a radiolysis model calculation was conducted with Hitachi's radiolysis analysis code 'SIMFONY'. For the calculation, the temperature range was set from 50 to 250°C with 50°C increments and the gamma dose rate was set at 60 Gys −1 to see the effect of gamma irradiation from fuels under shutdown conditions. Concentrations of radiolytic species were calculated for 10 5 s. Dilution ratio of seawater was changed to see the effects of concentration of seawater components. Reaction rate constants of the Cl − , Br − , HCO 3 − , and SO 4 2− systems were considered. The main radiolytic species were predicted to be hydrogen and oxygen. Hydrogen peroxide of low concentration was produced in seawater-mixed water at elevated temperatures. Compared with these main products, concentrations of radiolytic products originating from chloride ion and other seawater components were found to be rather low. The dominant product among them was ClO 3 − and its concentration was found to be below 0.01ppm at 10 5 s. Then, during the plant shutdown operation, the harmful influence from radiolytic species originating from seawater components on integrity of fuel materials must be smaller than that of chloride ion which is the main ionic species in seawater. (author)

Diffusion in the uranium - plutonium system and self-diffusion of plutonium in epsilon phase; Diffusion dans le systeme uranium-plutonium et autodiffusion du plutonium epsilon

Energy Technology Data Exchange (ETDEWEB)

Dupuy, M [Commissariat a l' Energie Atomique, Fontenay-Aux-Roses (France). Centre d' Etudes Nucleaires

1967-07-01

A survey of uranium-plutonium phase diagram leads to confirm anglo-saxon results about the plutonium solubility in {alpha} uranium (15 per cent at 565 C) and the uranium one in {zeta} phase (74 per cent at 565 C). Interdiffusion coefficients, for concentration lower than 15 per cent had been determined in a temperature range from 410 C to 640 C. They vary between 0.2 and 6 10{sup 12} cm{sup 2} s{sup -1}, and the activation energy between 13 and 20 kcal/mole. Grain boundary, diffusion of plutonium in a uranium had been pointed out by micrography, X-ray microanalysis and {alpha} autoradiography. Self-diffusion of plutonium in {epsilon} phase (bcc) obeys Arrhenius law: D = 2. 10{sup -2} exp -(18500)/RT. But this activation energy does not follow empirical laws generally accepted for other metals. It has analogies with 'anomalous' bcc metals ({beta}Zr, {beta}Ti, {beta}Hf, U{sub {gamma}}). (author) [French] Une etude du diagramme d'equilibre uranium-plutonium conduit a confirmer les resultats anglo-saxons relatifs a la solubilite du plutonium dans l'uranium {alpha} (15 pour cent a 565 C) et de l'uranium dans la phase {zeta} (74 pour cent a 565 C). Les coefficients de diffusion chimique, pour des concentrations inferieures a 15 pour cent ont ete determines a des temperatures comprises entre 410 et 640 C. Ils se situent entre 0.2 et 6. 10{sup 12} cm{sup 2} s{sup -1}. L'energie d'activation varie entre 13 et 20 kcal/mole. La diffusion intergranulaire du plutonium dans l'uranium a a ete mise en evidence par micrographie, microanalyse X et autoradiographie {alpha}. L' autodiffusion du plutonium {beta} cubique centree obeit a la loi d'Arrhenius D = 2. 10{sup -2} exp - (18500)/RT. Son energie d'activation n'obeit pas aux lois empiriques generalement admises pour les autres metaux. Elle possede des analogies avec les cubiques centres ''anormaux'' (Zr{beta}, Ti{beta}, Hf{beta}, U{gamma}). (auteur)

A method for the gravimetric determination of plutonium in pure plutonium nitrate concentrate solution

International Nuclear Information System (INIS)

Mair, M.A.; Savage, D.J.

1986-12-01

Plutonium nitrate solution is treated with sulphuric acid before being heated and finally ignited. The stoichiometric plutonium dioxide so formed is weighed and hence the plutonium content is calculated. (author)

F. Biological hazards of plutonium

International Nuclear Information System (INIS)

1976-01-01

Plutonium is an unavoidable result of present nuclear power programmes. Its predominant isotopes are extremely long-lived and very toxic if absorbed in the body. In view of the increasing potential for plutonium and man to come into contact, the consequences of any plutonium release into the environment should be scientifically examined. This report is an attempt to place in one document a fully referenced account of the on-going work in many areas. There are three sections. Part 1 deals with the amounts of plutonium available in the fuel cycle, its properties and the probability of routine or accidental release. Part 2 examines the ways in which plutonium can reach man, in particular through food chains or inhalation. Part 3 details the biological effects of plutonium once it is absorbed into the body, assesses the amounts likely to be harmful and discusses the adequacy of present standards for plutonium burdens. There are two appendices. The likely differences between Pu-239, the most studied isotope, and other plutonium isotopes or transuranic nuclides are outlined in Appendix A. Appendix B contains a fuller account of the ways in which the fate of ingested or inhaled plutonium have been determined

Use of plutonium for power production

International Nuclear Information System (INIS)

1965-01-01

The panel reviewed available information on various aspects of plutonium utilization, such as physics of plutonium, technology of plutonium fuels in thermal and fast reactors, behaviour of plutonium fuel under reactor irradiation, technological and economic aspects of plutonium fuel cycle. Refs, figs and tabs

HB-Line Plutonium Oxide Data Collection Strategy

Energy Technology Data Exchange (ETDEWEB)

Watkins, R. [Savannah River Nuclear Solutions; Varble, J. [Savannah River Nuclear Solutions; Jordan, J. [Savannah River Nuclear Solutions

2015-05-26

identifies the required facility procedures, DCS print outs, and laboratory results needed to assemble a final data package for each HB-Line plutonium oxide interim oxide can. The data traveler may identify the specific values (data) required to be extracted from the collected facility procedures and DCS print outs. The data traveler may also identify associated criteria to be checked. Inevitably there will be procedure anomalies during the course of the HB-Line plutonium oxide campaign that will have to be addressed in a timely manner.

World status report: plutonium

International Nuclear Information System (INIS)

Dircks, W.

1992-01-01

In a recent speech in Japan, the Deputy Director General of the International Atomic Energy Agency (IAEA) said that the economic case for reprocessing spent nuclear fuel had been severely eroded. An edited version of the speech is given. The changed prospects for nuclear energy is given as the reason why the demand for plutonium has declined sharply. The oil crisis of the 1970s reduced the demand for electric power and the economic justification for the use of recycled plutonium. The stockpile of isolated plutonium is growing rapidly giving rise to worries about its security. From this point of view, isolated plutonium is best kept in reactor fuel not separated out. In this connection the IAEA has offered to help in the storage of plutonium so that vigorous safety and security requirements are met. In Japan there is a debate about the plutonium which is dependent on the future of the fast breeder reactor programme. (UK)

Graphic-analytical determination of statics of reduction reextraction of plutonium using iron(2) as a reducing agent

International Nuclear Information System (INIS)

Pochinajlo, A.

1977-01-01

The grafic technological scheme of reduction reextraction of plutonium has been designed and the experiments on the laboratory 16-staged extractor of a mixer-settler type have been carried. From the concentration profiles found for a steady stage the content of plutonium(4) and plutonium(3) in organic and water phases in every stage is calculated. Then using the equations of material balance and extraction equilibrium a kinetic formula describing the reduction of plutonium(4) by iron(2f.) in a separate stage is deduced. Since the kinetic parameter A has been found to be close for all the staqes the analytical expression has been obtained with the help of which it is possible to determine a priori the plutonium(4) concentration profile in a reextraction part of the extractor for the given technological process conditions characterized by the defenite A. The plutonium(4) concentration profiles for the organic phase with different values A are presented

Radiolysis of solutions in anthraquinone derivatives

International Nuclear Information System (INIS)

Kriminskaya, Z.K.

1996-01-01

Stationary radiolysis of anthraquinones in solutions of ethanol, propanol-2 and water by gamma-radiation (dose rate of 1.6 Gy/s) is studied. It is shown that anthraquinones are reduced in the above solutions up to anthrahydroquinones, whereby all reduction particles participate in the reduction process. The reverse process of the post-radiation oxidation of anthrahydroquinones up to anthraquinones is a radical process

Measurement of total alpha activity of neptunium, plutonium, and americium in highly radioactive Hanford waste by iron hydroxide precipitation and 2-heptanone solvent extraction

International Nuclear Information System (INIS)

Maiti, T.C.; Kaye, J.H.

1992-06-01

An improved method has been developed to concentrate the major alpha-emitting actinide elements neptunium, plutonium, and americium from samples with high salt content such as those resulting from efforts to characterize Hanford storage tank waste. Actinide elements are concentrated by coprecipitation of their hydroxides using iron carrier. The iron is removed by extraction from 8M HCI with 2-heptanone. The actinide elements remain in the aqueous phase free from salts, iron, and long-lived fission products. Recoveries averaged 98 percent

Plutonium Finishing Plant

Data.gov (United States)

Federal Laboratory Consortium — The Plutonium Finishing Plant, also known as PFP, represented the end of the line (the final procedure) associated with plutonium production at Hanford.PFP was also...

Double shell tanks plutonium inventory assessment

International Nuclear Information System (INIS)

Tusler, L.A.

1995-01-01

This report provides an evaluation that establishes plutonium inventory estimates for all DSTs based on known tank history information, the DST plutonium inventory tracking system, tank characterization measurements, tank transfer records, and estimated average concentration values for the various types of waste. These estimates use data through December 31, 1994, and give plutonium estimates as of January 1, 1995. The plutonium inventory values for the DSTs are given in Section 31. The plutonium inventory estimate is 224 kg for the DSTs and 854 kg for the SSTs for a total of 1078 kg. This value compares favorably with the total plutonium inventory value of 981 kg obtained from the total plutonium production minus plutonium recovery analysis estimates

γ-radiolysis of dialkyl, alkyl-aryl and diaryl sulphones

International Nuclear Information System (INIS)

Bowmer, T.N.; O'Donnell, J.H.

1981-01-01

Dialkyl sulphones, RSO 2 R, have been considered as model compounds for the radiolysis of poly(olefin sulphone)s. They show preferential C-S scission and SO 2 elimination, attributable to the relatively low strengths of these bonds. Combination of the alkyl radicals, which are produced singly or in pairs according to whether one or two C-S scissions occur in one molecule, competes with hydrogen abstraction from sulphone molecules. The latter is favoured for single C-S scissions and as the size of the radical increases and hence its mobility decreases. An important degradation reaction in radiolysis is considered to be ionization to form the cation radical of the dialkyl sulphone, followed by a single C-S scission to produce the alkyl radical and the complementary alkyl sulphonyl cation, which may undergo scission of the remaining C-S bond to produce SO 2 . GC/MS studies of the volatile products from dimethyl sulphone have shown that radiolysis results in a complexity of fragmentation and combination reactions, involving scission of most bonds in the molecule. The variety of products has been confirmed using CD 3 SO 2 CD 3 . Radiation protection by aromatic substituents has been demonstrated and branched alkyls have been shown to give higher yields of alkanes and SO 2 than linear alkyls. (author)

Interfacing solvent extraction in the recovery of pyrochemical residues at the Savannah River Plant

International Nuclear Information System (INIS)

Gray, L.W.; Holcomb, H.P.

1986-01-01

The traditional feedstock for plutonium recovery at the Savannah River Plant (SRP) has been spent reactor fuel elements and irradiated targets. Feed sources have included both onsite reactors and a wide variety of domestic and foreign reactors. For the past few years, a growing and increasingly varied mix of unirradiated plutonium residues has been purified through SRP aqueous-based processes. Recently, plutonium residues generated in various chloride salt melts have become a significant offsite source of feed for SRP recovery operations. Impure plutonium metal and plutonium alloys have also been processed. A broader range of molten salt and other high temperature residues is anticipated for the future. The major advantage of solvent extraction for scrap purification is the versatility of the solvent extraction system which allows numerous contaminants to be removed by routine operations. Major concerns are nuclear safety control, corrosion of equipment, and control of releases to the environment. SRP's past, present, and future interfacing of solvent extraction in processing pyrochemical and other plutonium-containing residues is reviewed

Literature Review: Crud Formation at the Liquid/Liquid Interface of TBP-Based Solvent-Extraction Processes

Energy Technology Data Exchange (ETDEWEB)

Delegard, Calvin H.; Casella, Amanda J.

2016-09-30

This report summarizes the literature reviewed on crud formation at the liquid:liquid interface of solvent extraction processes. The review is focused both on classic PUREX extraction for industrial reprocessing, especially as practiced at the Hanford Site, and for those steps specific to plutonium purification that were used at the Plutonium Reclamation Facility (PRF) within the Plutonium Finishing Plant (PFP) at the Hanford Site.

Determination of plutonium in environment

International Nuclear Information System (INIS)

Sakanoue, Masanobu

1978-01-01

Past and present methods of determining the amount of plutonium in the environment are summarized. Determination of the amount of plutonium in uranium ore began in 1941. Plutonium present in polluted environments due to nuclear explosions, nuclear power stations, etc. was measured in soil and sand in Nagasaki in 1951 and in ash in Bikini in 1954. Analytical methods of measuring the least amount of plutonium in the environment were developed twenty years later. Many studies on and reviews of these methods have been reported all over the world, and a standard analytical procedure has been adopted. A basic analytical method of measurement was drafted in Japan in 1976. The yield, treatment of samples, dissolution, separation, control of measurable ray sources determination by α spectrometry, cross-check determination, and treatment of samples containing hardly soluble plutonium were examined. At present, the amount of plutonium can be determined by all of these methods. The presence of plutonium was studied further, and the usefulness of determination of the plutonium isotope ratio is discussed. (Kumagai, S.)

Oxidation of ortho- and para-aminobenzoic acid. A pulse radiolysis- and gamma radiolysis study

International Nuclear Information System (INIS)

Solar, Sonja; Getoff, Nikola; Zona, Robert; Solar, Wolfgang

2011-01-01

The oxidation of anthranilic acid (ortho-aminobenzoic acid, ANA) and para-aminobenzoic acid (PABA) by · OH, N 3 · and O ·- in basic solution was studied by pulse radiolysis. The kinetic and spectroscopic characteristics of the intermediate transients were determined. For ANA the site attack of the OH radicals was established to be ∼50% on the -NH 2 moiety and ∼50% on the aromatic ring with an overall rate constant k( · OH+ANA)=(5.5x10 9 ) dm 3 mol -1 s -1 . The rate constant of PABA was k( · OH+PABA)=8x10 9 dm 3 mol -1 s -1 . The OH-adducts of both compounds showed a first order decay of 0.8x10 5 and 1.2x10 5 s -1 , respectively, whereby the corresponding anilino-radicals were formed. The rate constant of ANA with solvated electrons was k(e - aq +ANA)=2.9x10 9 dm 3 mol -1 s -1 . The radiation induced decomposition of both substrates was studied by gamma radiolysis as a function of the absorbed dose. They exhibited a distinct radiation resistance, the initial degradation yields were ∼0.16 μmol J -1 , i.e. only 28% of the · OH radicals contributed to their decomposition. The hydroxylation process was of minor importance, the yield of hydroxylated aminobenzoic acids was≤0.01 μmol J -1 .

Multi-generational stewardship of plutonium

International Nuclear Information System (INIS)

Pillay, K.K.S.

1997-01-01

The post-cold war era has greatly enhanced the interest in the long-term stewardship of plutonium. The management of excess plutonium from proposed nuclear weapons dismantlement has been the subject of numerous intellectual discussions during the past several years. In this context, issues relevant to long-term management of all plutonium as a valuable energy resource are also being examined. While there are differing views about the future role of plutonium in the economy, there is a recognition of the environmental and health related problems and proliferation potentials of weapons-grade plutonium. The long-term management of plutonium as an energy resource will require a new strategy to maintain stewardship for many generations to come

Study of the radiolysis of tetracycline hidrochloride in aerated aqueous solutions

International Nuclear Information System (INIS)

Guedes, S.M.L.; Vasconcellos, M.B.A.

1983-01-01

The radiolysis of tetracycline hydrochloride (TC) was studied in neutral, acid and alkaline aerated solutions, by electron spin resonance spectroscopy at 77K. The paramagnetic species observed are: H.; OH.; HO 2 .; e - trapped and impurity radical. The reaction mechanism shows that the solute reacts with the solvent before the radiolysis and produces H + ions, as a consequence of the ionization of tricarbonylmethane group. The H + ions react with the e - from the radiolysis of water and produce HO 2 in the presence of O 2 . The interaction of TC with the alkaline solvent favours the interaction between gamma rays and solute. The products formed in the interaction of solute with the solvent before the radiolysis, as a consenquence of the ionization of TC, according to the pH of the solution, are of fundamental importance in the interaction of gamma rays with the solute. A crude estimate of the average distance that the e - is able to travel through solvent molecules before its capture by the solute was obtained in these 0.1N, 0.5N and 1.0N NaOH aqueous solutions. Until [TC] - travels more in solutions that contain less [NaOH]. In higher [TC] the e - travels through 680 solvent molecules. In order to explain the selective capture of the e3- by solute molecules, a simple model is suggested based on the existence of channel walls of solvent molecules where the electrical atraction betwwed Na + and e - influences the collision frequency and the energy loss. (Author) [pt

Development of analytical methods for the separation of plutonium, americium, curium and neptunium from environmental samples

Energy Technology Data Exchange (ETDEWEB)

Salminen, S.

2009-07-01

In this work, separation methods have been developed for the analysis of anthropogenic transuranium elements plutonium, americium, curium and neptunium from environmental samples contaminated by global nuclear weapons testing and the Chernobyl accident. The analytical methods utilized in this study are based on extraction chromatography. Highly varying atmospheric plutonium isotope concentrations and activity ratios were found at both Kurchatov (Kazakhstan), near the former Semipalatinsk test site, and Sodankylae (Finland). The origin of plutonium is almost impossible to identify at Kurchatov, since hundreds of nuclear tests were performed at the Semipalatinsk test site. In Sodankylae, plutonium in the surface air originated from nuclear weapons testing, conducted mostly by USSR and USA before the sampling year 1963. The variation in americium, curium and neptunium concentrations was great as well in peat samples collected in southern and central Finland in 1986 immediately after the Chernobyl accident. The main source of transuranium contamination in peats was from global nuclear test fallout, although there are wide regional differences in the fraction of Chernobyl-originated activity (of the total activity) for americium, curium and neptunium. The separation methods developed in this study yielded good chemical recovery for the elements investigated and adequately pure fractions for radiometric activity determination. The extraction chromatographic methods were faster compared to older methods based on ion exchange chromatography. In addition, extraction chromatography is a more environmentally friendly separation method than ion exchange, because less acidic waste solutions are produced during the analytical procedures. (orig.)

Plutonium in the marine environment

International Nuclear Information System (INIS)

Jarvis, N.V.; Linder, P.W.; Wade, P.W.

1994-01-01

The shipping of plutonium from Europe to Japan around the Cape is a contentious issue which has raised public concern that South Africa may be at risk to plutonium exposure should an accident occur. The paper describes the containers in which the plutonium (in the form of plutonium oxide, PuO 2 ) is housed and consequences of the unlikely event of these becoming ruptured. Wind-borne pollution is considered not to be a likely scenario, with the plutonium oxide particles more likely to remain practically insoluble and sediment. Plutonium aqueous and environmental chemistry is briefly discussed. Some computer modelling whereby plutonium oxide is brought into contact with seawater has been performed and the results are presented. The impact on marine organisms is discussed in terms of studies performed at marine dump sites and after the crash of a bomber carrying nuclear warheads in Thule, Greenland in 1968. Various pathways from the sea to land are considered in the light of studies done at Sellafield, a reprocessing plant in the United Kingdom. Some recent debates in the popular scientific press, such as that on the leukemia cluster at Sellafield, are described. Plutonium biochemistry and toxicity are discussed as well as medical histories of workers exposed to plutonium. 35 refs., 2 tabs., 1 fig

Plutonium association with selected solid phases in soils of Rocky Flats, Colorado, using sequential extraction technique

International Nuclear Information System (INIS)

Litaor, M.I.; Ibrahim, S.A.

1996-01-01

Plutonium contamination in the soil environs of Rock Flats, CO, has been a potential health risk to the public since the late 1960s. Although the measurement of total activity of Pu-239 + 240 in the soil is important information in appraising this risk, total activity does not provide the information required to characterize the geochemical behavior that affects the transport of Pu from the soil and vadose zone to groundwater. A sequential extraction experiment was conducted to assess the geochemical association of Pu with selected mineralogical and chemical phases of the soil. In the surface horizons, Pu-239 + 240 was primarily associated with the organic C (45-65%), sesquioxides (20-40%), and the residual fraction (10-15%). A small portion of Pu-239+240 was associated with soluble (0.09-0.22%), exchangeable (0.04-0.08%), and carbonates (0.57-7.0%) phases. These results suggest that under the observed pH and oxic conditions, relatively little Pu-239 + 240 is available for geochemically induced transport processes. Uncommon hydrogeochemical conditions were observed during the spring of 1995, which may have facilitated a partial dissolution of sesquioxides followed by desorption of Pu resulting in increased Pu mobility. Systematic errors in the sequential extraction experiment due to postextraction readsorption were evaluated using Np-237 tracer as a surrogate to Pu-239. The results suggested that postextraction readsorption rates were insignificant during the first 30 min after extraction for most chemical and mineralogical phases under study. 50 refs., 2 figs., 5 tabs

Pulse radiolysis studies on DNA-Binding radioprotectors

International Nuclear Information System (INIS)

Anderson, R.F.

1996-01-01

Full text: Hoechst 33342 and newly-synthesised analogues exhibit radioprotective activity in cultured cells and in vivo, as described in accompanying abstracts. These minor groove binding ligands bind at discreet sites in DNA, characterised by 3 to 4 consecutive AT base pairs, and DNA sequencing studies have shown focussed radioprotection at these binding sites. There is evidence that the bound ligands also confer more 'global' protection including the intervening DNA between the binding sites. The observed focussed radioprotection could be explained by H-atom donation from the ligand to radiation-induced carbon-centred deoxyribosyl radicals, but this mechanism is unlikely to account for the global radioprotection. We now report pulse radiolysis studies on another possible mechanism, namely reduction of transient radiation-induced oxidising species on DNA by the ligand, which is consistent with the report of reduction of G + by TMPD. Oxidation of deoxyguanosine (dG) by Br 2 - , produced by radiolysis of Br- in N 2 0-saturated solutions, in the presence of Hoechst 33342 results in the appearance of a transient ligand species which is kinetically resolvable from that obtained from direct oxidation of Hoechst 33342 by Br 2 - . A plot of reaction rate versus ligand concentration indicates that the rate constant for reduction of G + is approximately 3 x 10 8 dm 3 M -1 sec -1 . Similar experiments with DNA, rather than dG, also revealed a transient species corresponding to oxidation of the ligand, but the absolute rate of oxidation was considerably slower for the DNA-bound ligand compared to that for oxidation of the free ligand by G+. These results are clearly consistent with the proposed mechanism of radioprotection by Hoechst 33342 and its analogues, moreover, pulse radiolysis may provide a very useful endpoint for screening new analogues, as a preliminary to radiobiological evaluation

Radiolysis of cyanocobalamin (vitamin B{sub 12})

Energy Technology Data Exchange (ETDEWEB)

Juanchi, X.; Albarran, G.; Negron-Mendoza, A

2000-03-01

Research on the radiolysis of vitamins is of considerable interest since these compounds are important nutritional constituents in foods and in dietetic supplements. In spite of these considerations there are few data and very often difficult to compare for the radiolytic behavior of vitamins. In this work we focused our attention on to the study of the radiolysis of cyanocobalamin (vitamin B{sub 12}) in solid state and in aqueous solutions. The procedure was followed by HPLC and UV-spectroscopy. The results obtained in aqueous solutions showed a dependence of the decomposition as a linear function of the dose. The G of decomposition for a 1x10{sup -5} M solution was 3.3. In the solid state the vitamin was very stable towards the irradiation in the conditions used in this study with a G=2.1x10{sup -3}. A study made with Serratia marcescens as a microbiological contaminant showed that at the sterilization dose there is a destruction of the vitamin in aqueous solution. In the solid state the degree of decomposition was 7%. (author)

Evaluation of extractants and chelating resins in polishing actinide-contaminated waste streams

International Nuclear Information System (INIS)

Schreiber, S.B.; Dunn, S.L.; Yarbro, S.L.

1991-06-01

At the Los Alamos National Laboratory Plutonium Facility, anion exchange is used for recovering plutonium from nitric acid solutions. Although this approach recovers >99%, the trace amounts of plutonium and other actinides remaining in the effluent require additional processing. We are doing research to develop a secondary unit operation that can directly polish the effluent so that actinide levels are reduced to below the maximum allowed for facility discharge. We selected solvent extraction, the only unit operation that can meet the stringent process requirements imposed; several carbonyl and phosphoryl extractants were evaluated and their performance characterized. We also investigated various engineering approaches for solvent extraction; the most promising was a chelating resin loaded with extractant. Our research now focuses on the synthesis of malonamides, and our goal is to bond these extractants to a resin matrix. 7 refs., 12 figs., 1 tab

Progress in radiation chemistry of crown ether extractants used for the solvent extraction of "9"0Sr

International Nuclear Information System (INIS)

Peng Jing; Yu Chuhong; Cui Zhenpeng; Zhai Maolin

2011-01-01

The separation of the long-lived fission products from dissolved nuclear fuel could improve the safe disposal of high-level nuclear wastes and reduce their threaten to human being and environment. Since the extractant system will be exposed to high radiation environment during the solvent extraction of long-lived fission products. The understanding of radiation chemistry of extractants is very important for practical design of extractant system. The radiation chemistry of crown ether systems proposed for use in the solvent extraction of one of fission products "9"0Sr were reviewed based on the study on the radiation stability and radiolysis mechanism of crown ether system. Finally some challenges were suggested. (authors)

Plutonium Training Opportunities

Energy Technology Data Exchange (ETDEWEB)

Balatsky, Galya Ivanovna [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wolkov, Benjamin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2015-03-26

This report was created to examine the current state of plutonium training in the United States and to discover ways in which to ensure that the next generation of plutonium workers are fully qualified.

Pulse radiolysis study on aqueous solution of nicotine

International Nuclear Information System (INIS)

Wang Shilong; Mei Wang; Ni Yaming; Yao Side; Wang Wenfeng

2004-01-01

Nicotine has been studied for the first time by pulse radiolysis techniques. It has been found that hydrated electrons, hydrogen radicals and hydroxyl radicals can react with nicotine to produce anion radicals and neutral radicals, respectively, and the related rate constants have been determined. (authors)

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.

Optimizing Plutonium stock management

International Nuclear Information System (INIS)

Niquil, Y.; Guillot, J.

1997-01-01

Plutonium from spent fuel reprocessing is reused in new MOX assemblies. Since plutonium isotopic composition deteriorates with time, it is necessary to optimize plutonium stock management over a long period, to guarantee safe procurement, and contribute to a nuclear fuel cycle policy at the lowest cost. This optimization is provided by the prototype software POMAR

Recovery of uranium and plutonium from Redox off-standard aqueous waste streams

Energy Technology Data Exchange (ETDEWEB)

Holm, C.H.; Matheson, A.R.

1949-12-31

In the operation of countercurrent extraction columns as in the Redox process, it is possible, and probable, that from unexpected behaviour of a column, operator error, colloid formation, etc., there will result from time to time excessive losses of uranium and plutonium in the overall process. These losses will naturally accumulate in the waste streams, particularly in the aqueous waste streams. If the loss is excessively high, and such lost material can be recovered by some additional method, then if economical and within reason, the recovered materials ran be returned to a ISF column for further processing. The objective of this work has been to develop such a method to recover uranium and plutonium from such off-standard waste streams in a form whereby the uranium send plutonium can be returned to the process line and subsequently purified and separated.

Treatment of plutonium contaminations

International Nuclear Information System (INIS)

Lafuma, J.

1983-01-01

Three kinds of plutonium contaminations were considered: skin contamination; contaminated wounds; contamination by inhalation. The treatment of these contaminations was studied for insoluble (oxide and metal forms) and soluble plutonium (complexes). The use of DTPA and therapeutic problems encountered with stable plutonium complexes were analyzed. The new possibilities of internal decontamination using Puchel and LICAM were evaluated [fr

Air effect on polycarbonate radiolysis

International Nuclear Information System (INIS)

Terence, Mauro C.; Araujo, Elmo S.; Guedes, Selma M.L.

1995-01-01

The formation and decay of radicals in the radiolysis of new type of polycarbonate (G scission = 0,73) was investigated by electron spin resonance spectroscopy in the presence and absence of air at room temperature. The air does not interfere in the formation of radicals because they are formed as consequence of direct interaction of radiation. But the air interferes in their decays. During the irradiation the air reacts with all isopropyl radicals and with 2/3 of phenoxy + phenyl radicals. (author). 5 refs., 3 figs

Plutonium uptake by plants from soil containing plutonium-238 dioxide particles. Final report

International Nuclear Information System (INIS)

Brown, K.W.; McFarlane, J.C.

1977-05-01

Three plant species--alfalfa, lettuce, and radishes were grown in soils contaminated with plutonium-238 dioxide (238)PuO2 at concentrations of 23, 69, 92, and 342 nanocuries per gram (nCi/g). The length of exposure varied from 60 days for the lettuce and radishes to 358 days for the alfalfa. The magnitude of plutonium incorporation as indicated by the discrimination ratios for these species, after being exposed to the relatively insoluble PuO2, was similar to previously reported data using different chemical forms of plutonium. Evidence indicates that the predominant factor in plutonium uptake by plants may involve the chelation of plutonium contained in the soils by the action of compounds such as citric acid and/or other similar chelating agents released from the plant roots

Analytical methods used in plutonium purification cycles by trilaurylamine; Methodes analytiques utilisees dans les cycles de purification du plutonium par la trilaurylamine

Energy Technology Data Exchange (ETDEWEB)

Perez, J J [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1965-07-01

The utilisation of trilaurylamine as a solvent extractant for the purification of plutonium has entailed to perfect a set of analytical methods which involves, various techniques. The organic impurities of the solvent can be titrated by gas-liquid chromatography. The titration of the main degradation product, the di-laurylamine, can be accomplished also by spectro-colorimetry. Potentiometry is used for the analysis of the different salts of amine-nitrate-sulfate-bisulfate as also the extracted nitric acid. The determination of the nitrate in aqueous phase is carried out by constant current potentiometry. The range of application, the accuracy and the procedure of these analysis are related in the present report. (author) [French] L'utilisation de la trilaurylamine comme solvant d'extraction pour la purification du plutonium a necessite la mise au point d'un ensemble de methodes analytiques qui ressortent de techniques diverses. Les impuretes organiques du solvant peuvent etre dosees par chromatographie gaz-liquide. Le dosage du principal produit de degradation, la dilaurylamine, peut egalement etre effectue par spectrocolorimetrie. La potentiometrie est utilisee pour les analyses des differents sels d'amine: nitrate, sulfate, bisulfate, ainsi que de l'acide nitrique extrait. La determination des nitrates en phase aqueuse est executee par potentiometrie a courant impose. Le domaine d'application, la precision et le mode operatoire de ces analyses sont indiques dans le present rapport. (auteur)

Pulse radiolysis study of supercritical water-G-value measurement up to 450 degree C

International Nuclear Information System (INIS)

Katsumura, Y.

2006-01-01

It is widely recognized that the understanding of water radiolysis at elevated temperatures is inevitably important in the field of water chemistry in light water reactors because water radiolysis is closely related to many subjects such as hydrogen water chemistry (H 2 injection), SCC (stress corrosion cracking), dose accumulation and so on. This situation would also be applied to the future reactor using supercritical water (>374 C, 22.1MPa) as a coolant, so called supercritical water-cooled reactor (SCWR). Therefore, it is important to investigate water radiolysis of supercritical water. In 1989 Prof. Oka, University of Tokyo, proposed the SCWR as a future reactor and done much design study. This reactor has many advantages such as high energy efficiency, applicability of experience accumulated in light water reactors and supercritical fissile plant, and compact structure. In 2002 the Department of Energy in USA has selected the SCWR as one of the six Generation IV reactors and fundamental research has started in different countries as a national or an international project. In the present research G-values of water radiolysis have been measured by using a pulse radiolysis method up to 450 degree C to obtain the fundamental data relevant to the development of the SCWR. In supercritical water, the pressure controls the density of water easily and it was found that the G-values are strongly dependent not only on temperature but also on density in supercritical water. After presentation of experimental method and its difficulties, temperature and density dependent G-values of water decomposition products in supercritical water would be summarized. (authors)

Plutonium isotopes in the environment

International Nuclear Information System (INIS)

Holm, E.

1977-12-01

Determination of plutonium and americium by ion exchange and alpha-spectrometry. Deposition of global fall-out and accumulated area-content of 238 Pu, 239 Pu, 240 Pu, 241 Pu, 242 Pu and 241 Am in central Sweden (62.3 deg N, 12.4 deg E), by using the lichen species Cladonia alpestris as bioindicator. Retention and distribution of plutonium in carpets of lichen and soil. Transfer of plutonium from lichen to reindeer and man. Absorbed dose in reindeer and man from plutonium. Basic studies of plutonium and americium in the western Mediterranean surface waters, with emphases on particulate form of the transuranics. (author)

Mathematical modeling of processes of nuclear fuel extraction reprocessing

International Nuclear Information System (INIS)

Rozen, A.M.; Zel'venskij, M.Ya.

1977-01-01

A mathematical model of extraction process in the mixer-settlers is given which describes both a simple step process and extraction complicated with chemical reactions. The extraction equilibrium is described on the basis of theoretical data on the extraction mechanism using the mass action law and contains one empirical constant. The equations for concentration extraction constants of uranium(6) and uranium(4), plutonium(3, 4, 6), neptunium(4, 6) and zirconium(4) depending on the solution ion strength are given, which are obtained by treatment of numerous experimental data. On the example of the reductive reextraction process it is shown that there is a good coincidence of the calculated results of the suggested model with the experimental ones by Mc-Kay. By the method of matematical modeling the uranium and plutonium separation processes without reducers are investigated. The purification improvement of uranium extract, for example, is followed by the deterioration of the data on the other end of cascade i.e. purification of plutonium reextract from uranium and vice versa. To obtain a high grade of separation is possible only in comparatively long cascades and, besides, the regime parameters should be precisely observed

Characterisation and activation of catalysts for recombination of radiolysis gas; Charakterisierung und Aktivierung von Katalysatoren zur Rekombination von Radiolysegas

Energy Technology Data Exchange (ETDEWEB)

Bolz, Michael; Koehler, Jan; Schorle, Rolf; Helf, Achim [EnBW Kernkraft GmbH, Philippsburg (Germany). Kernkraftwerk Philippsburg, Teilbereich Chemie

2011-07-01

Radiolysis gas is produced by radiolysis of cooling water during the operation of boiling water reactors. Small amounts of radiolysis gas can accumulate at dead ends of pipes in the water-steam circuit. Under certain conditions, it can accumulate even to higher concentrations. To avoid these accumulations, small catalysts are built in. As part of a diploma thesis, the catalysts were analysed and characterised. (orig.)

Hydrogen peroxide kinetics in water radiolysis

Science.gov (United States)

Iwamatsu, Kazuhiro; Sundin, Sara; LaVerne, Jay A.

2018-04-01

The kinetics of the formation and reaction of hydrogen peroxide in the long time γ- radiolysis of water is examined using a combination of experiment with model calculations. Escape yields of hydrogen peroxide on the microsecond time scale are easily measured with added radical scavengers even with substantial amounts of initial added hydrogen peroxide. The γ-radiolysis of aqueous hydrogen peroxide solutions without added radical scavengers reach a steady state limiting concentration of hydrogen peroxide with increasing dose, and that limit is directly proportional to the initial concentration of added hydrogen peroxide. The dose necessary to reach that limiting hydrogen peroxide concentration is also proportional to the initial concentration, but dose rate has a very small effect. The addition of molecular hydrogen to aqueous solutions of hydrogen peroxide leads to a decrease in the high dose limiting hydrogen peroxide concentration that is linear with the initial hydrogen concentration, but the amount of decrease is not stoichiometric. Proton irradiations of solutions with added hydrogen peroxide and hydrogen are more difficult to predict because of the decreased yields of radicals; however, with a substantial increase in dose rate there is a sufficient decrease in radical yields that hydrogen addition has little effect on hydrogen peroxide decay.

Plutonium oxides and uranium and plutonium mixed oxides. Carbon determination

International Nuclear Information System (INIS)

Anon.

Determination of carbon in plutonium oxides and uranium plutonium mixed oxides, suitable for a carbon content between 20 to 3000 ppm. The sample is roasted in oxygen at 1200 0 C, the carbon dioxide produced by combustion is neutralized by barium hydroxide generated automatically by coulometry [fr

Radiation chemistry in solvent extraction: FY2010 Research

Energy Technology Data Exchange (ETDEWEB)

Bruce J. Mincher; Leigh R. Martin; Stephen P. Mezyk

2010-09-01

This report summarizes work accomplished under the Fuel Cycle Research and Development (FCR&D) program in the area of radiation chemistry during FY 2010. The tasks assigned during FY 2010 included: • Development of techniques to measure free radical reaction kinetics in the organic phase. • Initiation of an alpha-radiolysis program • Initiation of an effort to understand dose rate effects in radiation chemistry • Continued work to characterize TALSPEAK radiation chemistry Progress made on each of these tasks is reported here. Briefly, a method was developed and used to measure the kinetics of the reactions of the •NO3 radical with solvent extraction ligands in organic solution, and the method to measure •OH radical reactions under the same conditions has been designed. Rate constants for the CMPO and DMDOHEMA reaction with •NO3 radical in organic solution are reported. Alpha-radiolysis was initiated on samples of DMDOHEMA in alkane solution using He ion beam irradiation and 211At isotope irradiation. The samples are currently being analyzed for comparison to DMDOHEMA ?-irradiations using a custom-developed mass spectrometric method. Results are also reported for the radiolytic generation of nitrous acid, in ?-irradiated nitric acid. It is shown that the yield of nitrous acid is unaffected by an order-of-magnitude change in dose rate. Finally, recent results for TALSPEAK radiolysis are reported, summarizing the effects on solvent extraction efficiency due to HDEHP irradiation, and the stable products of lactic acid and DTPA irradiation. In addition, results representing increased scope are presented for the radiation chemistry program. These include an investigation of the effect of metal complexation on radical reaction kinetics using DTPA as an example, and the production of a manuscript reporting the mechanism of Cs-7SB radiolysis. The Cs-7SB work takes advantage of recent results from a current LDRD program to understand the fundamental chemistry

The synthesis and analysis of diuloses and deoxydiuloses with special reference to the radiolysis products of fructose

International Nuclear Information System (INIS)

Den Drijver, L.

1979-12-01

The exposure of fruit to γ-irradiation is a technique that is receiving increasing attention as a practical and economic preservation method. The analysis of irradiated fruit is necessary in order to identify and quantify possible mutagenic and toxic products formed during irradiation. Water and carbohydrates are the main components of fruit, the carbohydrates consisting mainly of mono- and disaccharides. An investigation of the radiolysis products of sugars, with special reference to hexosuloses and hexosdiuloses as possible toxic and/or mutagenic agents, formed the basis of the work described in this thesis. A number of diuloses formally derived from D-fructose was synthesized for mutagenicity tests and as standards for an investigation of the radiolysis products of D-fructose. High pressure liquid chromatography was used as analytical technique. The investigation represents the first application of the technique for the analysis of radiolysis products of sugars. It was succesfully applied to a study of the diuloses formed by the radiolysis of D-fructose in the presence of oxygen. The results obtained confirmed earlier work carried out with GC-MS as analytical technique. In addition, a previously unknown radiolysis product of D-fructose was identified as D-erythrohexos-2,3-diulose

Cigarette smoke and plutonium

International Nuclear Information System (INIS)

Filipy, R.E.

1985-01-01

Autoradiographic techniques with liquid photographic emulsion and cellulose nitrate track-etch film are being used to investigate the spatial distribution of inhaled plutonium in the lungs of beagle dogs exposed to cigarette smoke or to the plutonium aerosol only. More plutonium than expected was detected on the inner surfaces of bronchi, and particles were observed beneath the bronchial mucosa. 2 figures, 2 tables

Design and synthesis of a new class of diamides for selective extraction of plutonium

International Nuclear Information System (INIS)

Mallampalli, Sivaramakrishna; Kumar, Amar; Nayak, S.K.; Nayak, Sandip K.; Raout, D.; Mohapatra, P.K.

2016-01-01

The immense interest in purification of plutonium (Pu) originated from its dual use both in domestic power production as well as in strategic applications. As on today, the most prevalent application for 238 Pu is its use as an important fuel for heat and power sources for space exploration. Recently, a useful Pu selective diamide solvent (BenzoDODA) in n-dodecane diluent has been reported with a relatively high distribution coefficient (6.74 at 3M HNO 3 and 9.5 at 6M HNO 3 ). This ligand showed a distribution ratio ∼ 2 at 0.5M HNO 3 and stripping was carried out with a mixture of N 2 H 4 (0.2M), HNO 3 (0.6M) and oxalic acid (0.1M). In diamide based solvents choice of spacer between two amide groups is important as the presence of coordinating group in the spacer may further augment its selectivity in metal ion extraction. This has been substantiated in the case of phenanthroline based diamides used in fuel reprocessing. Recently, triarylpyridine based ligands has generated interest as fluorophores for making metal ion chemo-sensors. Keeping in view of special attributes of heterocycle spacered diamides, we designed and synthesized a new class of diamides with 2,4,6-triarylpyridine as a spacer wherein amide functions are anchored in the aromatic rings at 2- and 6-positions for its use as solvent in nuclear fuel reprocessing. The triarylpyridine spacered diamide (TAP-diamide) was synthesized from 2,6-bis(3-hydroxyphenyl)-4-phenylpyridine using classical synthetic methodologies and its extraction potential was evaluated in the separation of Pu and other relevant metal ions including Pu after long term storage. Higher D Pu and separation factors (higher than the reported values for Pu with TAP-diamide using nitrobenzene as diluent over Am, Eu, Th, Zr were observed. However, due to toxicity of nitrobenzene, efforts are on to modify the structure of diamide so that dodecane/phase modifier can be used as a diluent towards Pu extraction. Following is the predominant

Development of subpicosecond pulse radiolysis system

International Nuclear Information System (INIS)

Kozawa, T.; Saeki, A.; Okamoto, K.; Numata, Y.; Kaseda, K.; Yamamoto, T.; Suemine, S.; Yoshida, Y.; Tagawa, S.

2000-01-01

Subpicosecond pulse radiolysis system was developed to elucidate the primary processes of radiation chemistry in the time region of femtosecond. The system consists of a femtosecond electron linac as an irradiation source, a femtosecond laser as an analyzing light and a jitter compensation system which was designed to reduce the effect of jitter between an electron pulse and a laser pulse on the time resolution. The time resolution of 800 fs was achieved. (author)

Hazards of plutonium and fuel reprocessing

International Nuclear Information System (INIS)

Watson, G.M.

1978-01-01

Apart from the possibility that civil plutonium may be diverted to military use the main argument against the introduction of a plutonium economy seems to be the supposedly unmanageable biological risk attached to plutonium itself. The author points out weaknesses in many of the opponents' arguments against the increased use of plutonium and argues that current safety practices are more than adequate in handling plutonium and other radioactive materials

BenzoDODA grafted polymeric resin—Plutonium selective solid sorbent

Energy Technology Data Exchange (ETDEWEB)

Ruhela, R., E-mail: riteshr@barc.gov.in [Materials Processing Division, Materials Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Panja, S., E-mail: surajit@barc.gov.in [Fuel Reprocessing Division, Nuclear Fuels Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Singh, A.K. [Materials Processing Division, Materials Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Dhami, P.S.; Gandhi, P.M. [Fuel Reprocessing Division, Nuclear Fuels Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

2016-11-15

Highlights: • BenzoDODA grafted polymeric resin was synthesized and evaluated for sorption of Pu(IV). • Fast sorption kinetics for ‘Pu(IV)’. • Ease of back extraction of ‘Pu’ form loaded resin. • Ease of recyclability and fair stability in HNO{sub 3} medium. - Abstract: A new ligand grafted polymeric resin (BenzoDODA SDVB) was synthesized by covalently attaching plutonium selective ligand (BenzoDODA) on to styrene divinyl benzene (SDVB) polymer matrix. BenzoDODA SDVB resin was evaluated for separation and recovery of plutonium(IV) from nitric acid medium. Sorption of Pu(IV) was found to decrease with the increase in nitric acid concentration, with very small sorption above 7.0 M HNO{sub 3}. Sorption kinetics was fast enough to achieve the equilibrium within 60 min of contact where the kinetic data fitted well to pseudo-second-order model. Sorption isotherm data fitted well to Langmuir model suggesting chemical interaction between the BenzoDODA moiety and plutonium(IV) ions. Sorption studies with some of representative radionuclides of high level waste showed that BenzoDODA SDVB is selective and therefore could be a promising solid sorbent for separation and recovery of plutonium. Further, the theoretical calculations done on BenzoDODA SDVB resin suggested Pu(NO{sub 3}){sub 4}·BenzoDODA (1:1) sorbed complex conformed to generally observed square antiprism geometry of the plutonium complexes, with contributions from oxygen atoms of four nitrate ions as well as from four oxygen atoms present in BenzoDODA (two phenolic ether oxygen atoms and two carbonyl oxygen atoms of amidic moiety).

Radiolysis of water confined in zeolites 4A: application to tritiated water storage

International Nuclear Information System (INIS)

Frances, Laetitia

2014-01-01

Self-radiolysis of tritiated water (HTO) adsorbed in zeolites 4A shows differences compared to free-bulk water radiolysis. We studied the roles of zeolites on that. We took special care with the influence of water loading ratio. We first exposed zeolites to external irradiations, reproducing selectively the dose or the dose rate measured in the case of tritiated water storage. This strategy enables the characterising of the samples after their irradiation since they are not contaminated by tritium. Those experiments revealed the high stability of zeolites 4A. We used a second approach which consisted in studying the precise case of self-radiolysis of tritiated water, in order to obtain radiolytic yields representative of HTO storage. The comparison between the quantities of gas released when zeolites are exposed to the three different sources that we used (electrons accelerated at 10 MeV, γ released by radioactive decay of 137 Cs and β - released by radioactive decay of tritium) revealed the strong influence of the dose rate. Moreover, whatever the irradiation source, zeolites 4A first favour hydrogen release and secondarily oxygen release too. On the contrary, zeolites favour next a recombination between those radiolytic products, with a dependence on their water loading ratio. Several processes are discussed to explain such a phenomena, not noticed during the free-bulk water radiolysis. (author) [fr

Construction of ion beam pulse radiolysis system

Energy Technology Data Exchange (ETDEWEB)

Chitose, Norihisa; Katsumura, Yosuke; Domae, Masafumi; Ishigure, Kenkichi; Murakami, Takeshi [Tokyo Univ. (Japan)

1996-10-01

An ion beam pulse radiolysis system has been constructed at HIMAC facility. Ion beam of 24 MeV He{sup 2+} with the duration longer than 1 {mu}s is available for irradiation. Three kinds of aqueous solutions, (C{sub 6}H{sub 5}){sub 2}CO, NaHCO{sub 3} and KSCN, were irradiated and the absorption signals were observed. (author)

Study of polysilane mainchain electronic structure by picosecond pulse radiolysis

International Nuclear Information System (INIS)

Habara, H.; Saeki, A.; Kunimi, Y.; Seki, S.; Kozawa, T.; Yoshida, Y.; Tagawa, S.

2000-01-01

The electronic structure of a charged polysilane molecle is studied. The transient absorption spectroscopy was carried out for charged radicals of poly (methylphenylsilane): PMPS by pico-second and nanosecond pulse radiolysis technique. It was observed that the peak of the transient absorption spectra shifted to longer wavelength region within a few nsec, and an increase was observed in the optical density at 370 nm, which had been already assigned to the radical anions of PMPS. It is ascribed to inter-segment electron transfer (intra-molecular transfer) through polymer chain. The nanosecond pulse radiolysis experiments gave similar kinetic traces in near-UV and IR region. This suggests the presence of an interband level, that is, a polaron level occupied by an excess electron or a hole. (author)

Plutonium spectrophotometric analysis

International Nuclear Information System (INIS)

Esteban, A.; Cassaniti, P.; Orosco, E.H.

1990-01-01

Plutonium ions in solution have absorption spectra so different that it is possible to use them for analytical purposes. Detailed studies have been performed in nitric solutions. Some very convenient methods for the determination of plutonium and its oxidation states, especially the ratios Pu(III):Pu(IV) and Pu(IV):Pu(VI) in a mixture of both, have been developed. These methods are described in this paper, including: a) Absorption spectra for plutonium (III), (IV), (VI) and mixtures. b) Relative extinction coefficients for the above mentioned species. c) Dependences of the relative extinction coefficients on the nitric acid concentration and the plutonium VI deviation from the Beer-Lambert law. The developed methods are simple and rapid and then, suitable in process control. Accuracy is improved when relative absorbance measurements are performed or controlled the variables which have effect on the spectra and extinction coefficients. (Author) [es

Plutonium safe handling

International Nuclear Information System (INIS)

Tvehlov, Yu.

2000-01-01

The abstract, prepared on the basis of materials of the IAEA new leadership on the plutonium safe handling and its storage (the publication no. 9 in the Safety Reports Series), aimed at presenting internationally acknowledged criteria on the radiation danger evaluation and summarizing the experience in the safe management of great quantities of plutonium, accumulated in the nuclear states, is presented. The data on the weapon-class and civil plutonium, the degree of its danger, the measures for provision of its safety, including the data on accident radiation consequences with the fission number 10 18 , are presented. The recommendations, making it possible to eliminate the super- criticality danger, as well as ignition and explosion, to maintain the tightness of the facility, aimed at excluding the radioactive contamination and the possibility of internal irradiation, to provide for the plutonium security, physical protection and to reduce irradiation are given [ru

Some of the properties of plutonium and the aluminium-plutonium alloy; Quelques proprietes du plutonium et de l'alliage aluminium-plutonium

Energy Technology Data Exchange (ETDEWEB)

Abramson, R; Boucher, R; Fabre, R; Monti, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1959-07-01

1- Study of the physical properties of plutonium. 1) Study of the allotropy of plutonium. a) Thermal analysis: the apparatus used and the measurement technique are briefly described. The transition point temperatures and the corresponding heats of transformation have been determined. Finally, the results of the particular study of certain transition points are given. b) Dilatometry. The dilatometric analysis of the phase changes of plutonium has been carried out by means of the Chevenard dilatometer with photographic recording. The testing conditions (heating and cooling speeds, isotherm plateaux) have been varied in order to determine accurately the characteristics of each transition, particularly the {delta} {yields} {gamma} transition on cooling. 2) Micrography of plutonium. For the accurate preparation of metallographic samples the electrolytic polishing must be rapid, which implies a mechanical polishing of excellent quality. Information is given on new attacking reagents which show the structure of the metal very clearly. 2- Study of aluminium-plutonium alloys. Comparative study of Al-Pu and Al-U alloys rich in aluminium. a) Thermal analysis. The liquids and fusion temperatures of the eutectic Al-XAl{sub 4}, have been accurately determined. From the measurement of the heats of fusion the exact composition of the eutectic alloy has been determined. b) Thermal treatments. The eutectic coalescence kinetics have been studied by a micrographic method and by following the evolution of hardness. The results obtained show that the phenomenon is more rapid in Al-Pu alloys than in Al-U alloys. c) Micrographic study of the transition XAl{sub 3} {yields} XAl{sub 4}. The peritectic reaction XAl{sub 3} + liq. {yields} XAl{sub 4} has been suppressed by quenching. The transformation of the XAl{sub 3} phase to the solid phase has been studied as well as the effect of small additions of silicon on the kinetics of this reaction. (author) [French] 1- Etude des proprietes

Burning weapons-grade plutonium in reactors

International Nuclear Information System (INIS)

Newman, D.F.

1993-06-01

As a result of massive reductions in deployed nuclear warheads, and their subsequent dismantlement, large quantities of surplus weapons- grade plutonium will be stored until its ultimate disposition is achieved in both the US and Russia. Ultimate disposition has the following minimum requirements: (1) preclude return of plutonium to the US and Russian stockpiles, (2) prevent environmental damage by precluding release of plutonium contamination, and (3) prevent proliferation by precluding plutonium diversion to sub-national groups or nonweapons states. The most efficient and effective way to dispose of surplus weapons-grade plutonium is to fabricate it into fuel and use it for generation of electrical energy in commercial nuclear power plants. Weapons-grade plutonium can be used as fuel in existing commercial nuclear power plants, such as those in the US and Russia. This recovers energy and economic value from weapons-grade plutonium, which otherwise represents a large cost liability to maintain in safeguarded and secure storage. The plutonium remaining in spent MOX fuel is reactor-grade, essentially the same as that being discharged in spent UO 2 fuels. MOX fuels are well developed and are currently used in a number of LWRs in Europe. Plutonium-bearing fuels without uranium (non-fertile fuels) would require some development. However, such non-fertile fuels are attractive from a nonproliferation perspective because they avoid the insitu production of additional plutonium and enhance the annihilation of the plutonium inventory on a once-through fuel cycle

Process for recovery of plutonium from fabrication residues of mixed fuels consisting of uranium oxide and plutonium oxide

International Nuclear Information System (INIS)

Heremanns, R.H.; Vandersteene, J.J.

1983-01-01

The invention concerns a process for recovery of plutonium from fabrication residues of mixed fuels consisting of uranium oxide and plutonium oxide in the form of PuO 2 . Mixed fuels consisting of uranium oxide and plutonium oxide are being used more and more. The plants which prepare these mixed fuels have around 5% of the total mass of fuels as fabrication residue, either as waste or scrap. In view of the high cost of plutonium, it has been attempted to recover this plutonium from the fabrication residues by a process having a purchase price lower than the price of plutonium. The problem is essentially to separate the plutonium, the uranium and the impurities. The residues are fluorinated, the UF 6 and PuF 6 obtained are separated by selective absorption of the PuF 6 on NaF at a temperature of at least 400 0 C, the complex obtained by this absorption is dissolved in nitric acid solution, the plutonium is precipitated in the form of plutonium oxalate by adding oxalic acid, and the precipitated plutonium oxalate is calcined

METHOD OF PRODUCING PLUTONIUM TETRAFLUORIDE

Science.gov (United States)

Tolley, W.B.; Smith, R.C.

1959-12-15

A process is presented for preparing plutonium tetrafluoride from plutonium(IV) oxalate. The oxalate is dried and decomposed at about 300 deg C to the dioxide, mixed with ammonium bifluoride, and the mixture is heated to between 50 and 150 deg C whereby ammonium plutonium fluoride is formed. The ammonium plutonium fluoride is then heated to about 300 deg C for volatilization of ammonium fluoride. Both heating steps are preferably carried out in an inert atmosphere.

The toxicity of plutonium

International Nuclear Information System (INIS)

Crouse, P.L.

1994-01-01

Shipments of plutonium occasionally pass around the Cape coastal waters on its way to Japan from Europe. This invariably leads to a great deal of speculation of the dangers involved and of the extreme toxicity of plutonium, with the media and environmental groups claiming that (a) plutonium is the most toxic substance known to man, and that (b) a few kilograms of plutonium ground finely and dispersed in the atmosphere could kill every human being on earth. Comparisons with other poisons are drawn, e.g. common inorganic chemicals and biological agents. The original scare around the extraordinary toxicity of Pu seems to have started in 1974 with the claims of Tamplin and Cochran's hot particle theory about plutonium lodging in the sensitive portions of the lungs in small concentrated aggregates where they are much more effective in producing cancers. This theory, however, is regarded as thoroughly discredited by the experts in the field of radiotoxicity. 8 refs

Plutonium use in foreign countries (03)

International Nuclear Information System (INIS)

Otagaki, Takao

2004-03-01

European countries and Japan had been implementing the strategy of spent fuel reprocessing in order to use nuclear material to the maximum. Plutonium recovered from reprocessing, however, must be recycle on light water reactors (LWRs) because of considerable delay of fast reactor development. In Europe, much of experiences of plutonium recycling have been accumulated until now. Thus, the status of plutonium recycling up to the end of 2003 in France, Germany, The U.K., Belgium, Switzerland and other countries were studied based on the following scope. (1) Basic policy and present status of plutonium recycling in primary countries of France, Germany, The U.K., Belgium, Switzerland, and Sweden which plans to recycle a part of plutonium: Backend policy and the status of spent fuel management were studied, then integrated analysis and evaluation of the position of plutonium recycling in backend and the status of plutonium recycling development were performed. (2) Plan and experience of Mixed Oxide (MOX) fuel fabrication and reprocessing of spent fuels: The data and information on plan and experience of MOX fuel fabrication and reprocessing in foreign countries were collected. (3) Plutonium inventories: The data and information of plutonium inventories of foreign countries were collected. (author)

Cigarette smoke and plutonium

International Nuclear Information System (INIS)

Filipy, R.E.

1983-01-01

The major objective of this project is to obtain experimental data that are directly applicable to resolving the question of whether cigarette smokers are at greater risk than nonsmokers to potential health effects of inhaled plutonium. Because cigarette smokers constitute a large fraction of the population, a synergistic effect of plutonium and cigarette smoke might influence estimates of the health risk for plutonium and other transuranics released to the environment

Cycle downstream: the plutonium question

International Nuclear Information System (INIS)

Zask, G.; Rome, M.; Delpech, M.

1998-01-01

This day, organized by the SFEN, took place at Paris the 4 june 1998. Nine papers were presented. They take stock on the plutonium physics and its utilization as a nuclear fuel. This day tried to bring information to answer the following questions: do people have to keep the plutonium in the UOX fuel or in the MOX fuel in order to use it for future fast reactors? Do people have to continue obstinately the plutonium reprocessing in the MOX for the PWR type reactors? Will it be realized a underground disposal? Can it be technically developed plutonium incinerators and is it economically interesting? The plutonium physics, the experimental programs and the possible solutions are presented. (A.L.B.)

GC-FTIR-MS analysis of volatile radiolytic products in the radiolysis of nitroaniline

International Nuclear Information System (INIS)

Kuruc, J.; Sahoo, M.K.; Kubinec, R.

1993-01-01

A good deal of products formed in the γ-radiolysis of isomeric nitroaniline solutions in carbon tetrachloride have been identified using GC-FTIR-MS technique. Tetrachloroethylene, chlorobenzene, hexachloroethane isomeric di-, tri- and tetrachlorobenzenes and chloroisocyanatobenzenes are among the important products formed in the radiolysis. Formation of dichlorobenzene is the result of ipso-substitution of both the nitro and aniline group by chlorine atom and the subsequent chloration of dichlorobenzene results in the formation of polychlorobenzenes. Chloroisocyanatobenzene is proposed to be the product arising from the interaction of dichlorocarbene and the nitro group of nitroaniline followed by chlorination of the resulting product, isocyanatobenzene. A 94% yield of undissolved 1,2-aminonitrobenzene chloride salt is obtained from the radiolysis of o-nitroaniline solution in carbon tetrachloride with a radiation yield of 1.83 molecules per 100 eV absorbed energy for an irradiation dose of 267 kGy. (author) 9 refs.; 3 figs.; 2 tabs

Investigation of environmental samples from Fukushima with respect to uranium and plutonium by AMS; Untersuchung von Umweltproben aus Fukushima in Bezug auf Plutonium und Uran mittels AMS

Energy Technology Data Exchange (ETDEWEB)

Schneider, Stephanie

2017-02-01

In March 2011, the nuclear power plant Fukushima Dai-ichi was seriously damaged by a tsunami caused by an earthquake. During the accident large quantities of radionuclides, mainly of the volatile elements cesium and iodine, were released to the environment. In small amounts refractory elements such as plutonium and uranium have also been released. Plutonium and the uraniumisotope {sup 236}U have primarily been delivered by human activities in the environment. Large amounts were released during the atmospheric nuclear weapons tests. Additional sources are accidents in nuclear facilities, like Chernobyl. Every source has its own characteristic isotopic composition. It is therefore possible to determine the origin of the contamination by measuring the isotopic ratios of {sup 240}Pu/{sup 239}Pu and {sup 236}U/{sup 238}U. These ratios can be determined by using accelerator mass spectrometry. Due to its high sensitivity, it is possible to measure even small amounts of plutonium and especially of {sup 236}U. These measurements were performed using the compact 500 kV facility ''TANDY'' of ETH Zurich. In 2013 and 2015 vegetation, litter and soil drill core samples were taken in the contaminated area in Fukushima prefecture. In 2015 samples were taken as close to the sampling locations of the 2013 campaign as possible. After isolation of plutonium and uranium by chemical extraction, separate targets were prepared for the measurement. The {sup 240}Pu/{sup 239}Pu ratios indicate global fallout as the plutonium source for most samples. The plutonium of the reactors of Fukushima Dai-ichi is located in the upper layers like in vegetation or litter. From the uranium ratios alone the reactors could not unambigously be identified as the source of {sup 236}U. However, this is plausible in the cases were reactor plutonium was detected. None of the samples contained higher plutonium activity concentrations than in the rest of Japan, caused by global fallout. This

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.

Studies on radiolysis of amino acids, (3)

International Nuclear Information System (INIS)

Oku, Tadatake

1978-01-01

For the purpose of investigating the radiolysis of amino acids and the safeness to radiation, the radiolytic mechanism and radio-sensitivity of sulfur-containing amino acids in aqueous solution in the presence of air or in the atmosphere of nitrogen were studied. Aqueous solutions of L-methionine, cysteine (both 1mM) and L-cystine (0.3mM) were irradiated with γ-ray of 60 Co at the dose of 4.2 - 2,640 x 10 3 rad. The amino acids and the radiolytic products were determined with an amino acid analyzer. The volatile sulfur compounds formed from γ-irradiated methionine were estimated by a flame photometric detector-gas chromatograph. From the results obtained, G values of the radiolysis of sulfur-containing amino acids and the products were calculated, and the radiolytic mechanisms of methionine, cysteine and cystine were proposed. The radio-sensitivity of sulfur-containing amino acids was shown as follows: cysteine (C3-SH) > methionine (C5, -SCH 3 ) > cystine (C 6 , -S-S-). Off-flavor development from γ-irradiated methionine when oxidizing agent was added was less than that when reducing agent was added. (Kobatake, H.)

Plutonium Proliferation: The Achilles Heel of Disarmament

International Nuclear Information System (INIS)

Leventhal, Paul

2001-01-01

Plutonium is a byproduct of nuclear fission, and it is produced at the rate of about 70 metric tons a year in the world's nuclear power reactors. Concerns about civilian plutonium ran high in the 1970s and prompted enactment of the Nuclear Non-Proliferation Act of 1978 to give the United States a veto over separating plutonium from U.S.-supplied uranium fuel. Over the years, however, so-called reactor-grade plutonium has become the orphan issue of nuclear non-proliferation, largely as a consequence of pressures from plutonium-separating countries. The demise of the fast breeder reactor and the reluctance of utilities to introduce plutonium fuel in light-water reactors have resulted in large surpluses of civilian, weapons-usable plutonium, which now approach in size the 250 tons of military plutonium in the world. Yet reprocessing of spent fuel for recovery and use of plutonium proceeds apace outside the United States and threatens to overwhelm safeguards and security measures for keeping this material out of the hands of nations and terrorists for weapons. A number of historical and current developments are reviewed to demonstrate that plutonium commerce is undercutting efforts both to stop the spread of nuclear weapons and to work toward eliminating existing nuclear arsenals. These developments include the breakdown of U.S. anti-plutonium policy, the production of nuclear weapons by India with Atoms-for-Peace plutonium, the U.S.-Russian plan to introduce excess military plutonium as fuel in civilian power reactors, the failure to include civilian plutonium and bomb-grade uranium in the proposed Fissile Material Cutoff Treaty, and the perception of emerging proliferation threats as the rationale for development of a ballistic missile defense system. Finally, immobilization of separated plutonium in high-level waste is explored as a proliferation-resistant and disarmament-friendly solution for eliminating excess stocks of civilian and military plutonium.

Gamma ray NDA assay system for total plutonium and isotopics in plutonium product solutions

International Nuclear Information System (INIS)

Cowder, L.R.; Hsue, S.T.; Johnson, S.S.; Parker, J.L.; Russo, P.A.; Sprinkle, J.K.; Asakura, Y.; Fukuda, T.; Kondo, I.

1979-01-01

A LASL-designed gamma-ray NDA instrument for assay of total plutonium and isotopics of product solutions at Tokai-Mura is currently installed and operating. The instrument is, optimally, a densitometer that uses radioisotopic sources for total plutonium measurements at the K absorption edge. The measured transmissions of additional gamma-ray lines from the same radioisotopic sources are used to correct for self-attenuation of passive gamma rays from plutonium. The corrected passive data give the plutonium isotopic content of freshly separated to moderately aged solutions. This off-line instrument is fully automated under computer control, with the exception of sample positioning, and operates routinely in a mode designed for measurement control. A one-half percent precision in total plutonium concentration is achieved with a 15-minute measurement

An autoradiographical method using an imaging plate for the analyses of plutonium contamination in a plutonium handling facility

International Nuclear Information System (INIS)

Takasaki, Koji; Sagawa, Naoki; Kurosawa, Shigeyuki; Mizuniwa, Harumi

2011-01-01

An autoradiographical method using an imaging plate (IP) was developed to analyze plutonium contamination in a plutonium handling facility. The IPs were exposed to ten specimens having a single plutonium particle. Photostimulated luminescence (PSL) images of the specimens were taken using a laser scanning machine. One relatively large spot induced by α-radioactivity from plutonium was observed in each PSL image. The plutonium-induced spots were discriminated by a threshold derived from background and the size of the spot. A good relationship between the PSL intensities of the spots and α-radioactivities measured using a radiation counter was obtained by least-square fitting, taking the fading effect into consideration. This method was applied to workplace monitoring in an actual uranium-plutonium mixed oxide (MOX) fuel fabrication facility. Plutonium contaminations were analyzed in ten other specimens having more than two plutonium spots. The α-radioactivities of plutonium contamination were derived from the PSL images and their relative errors were evaluated from exposure time. (author)

Gamma radiolysis effects on basalt groundwater

International Nuclear Information System (INIS)

Gray, W.J.

1983-10-01

Gamma radiolysis of basalt groundwater containing 700 ppM methane produces a milky liquid that is a suspension of fine particles of a high molecular weight hydrocarbon somewhat like polyethylene. The ability of these polymers to chelate with, or otherwise sorb, metal ions from aqueous solution was measured using Cu +2 as a representative cation. Values in the range 0.3 to 0.8 millimoles of Cu per liter of solution were found. 5 references, 2 figures, 2 tables

The extraction neptunium by trilaurylamine; L'extraction du neptunium par le trilaurylamine

Energy Technology Data Exchange (ETDEWEB)

Champion, J; Chesne, A [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1964-07-01

The extraction by trilaurylamine of neptunium (IV) from nitric acid and sulfuric acid-nitric acid media has been studied with the aim of developing a purification process for this element. Relative to the plutonium-neptunium separation, conditions are given for the oxidation of neptunium (IV) in sulfuric acid-nitric acid medium and data are presented on the stabilisation of the + 4 oxidation state by the organic solvent. Two procedures have been developed for the simultaneous purification of the two actinides. Both are based on the trilaurylamine extraction of the tetravalent nitrate species. The first utilises a constant redox potential fixed by Fe{sup +++} /Fe{sup ++} couple, while in the second, valencies are determined by successive addition of nitrite and ferrous ions. Gram quantities of neptunium 237 has been recovered from plutonium process solution. Alternate procedures are suggested for the chemical processing of irradiated Np{sup 237}. (authors) [French] L'extraction du neptunium par le trilaurylamine en milieu nitrique et sulfonitrique a ete etudiee dans le cadre de la recherche des procedes de purification de cet element. En vue d'effectuer la separation neptunium-plutonium on a precise d'une part les conditions d'oxydation du Np{sup 4+} en milieu sulfonitrique, d'autre part l'influence du solvant sur la stabilite des valences de ces deux elements. Deux procedes de purification simultanee des deux actinides ont ete developpes. Ils sont bases sur l'extraction du nitrate des elements tetravalents dans la trilaury lamine. Dans l'un, la solution a extraire a un potentiel redox fixe par un systeme auxiliaire (Fe{sup +++}/Fe{sup ++}), dans l'autre elle subit dans le meme extracteur des additions successives de nitrite et de fer ferreux. On decrit un essai semi-industriel de recuperation de neptunium 237 a partir de solution provenant de l'usine de production de plutonium de Marcoule. Differents schemas utilisables lors du traitement chimique des cibles de

Recovery of plutonium by pyroredox processing

International Nuclear Information System (INIS)

McNeese, J.A.; Bowersox, D.F.; Christensen, D.C.

1985-09-01

Using pyrochemical oxidation and reduction, we have developed a process to recover the plutonium in impure scrap with less than 95% plutonium. This plutonium metal was further purified by pyrochemical electrorefining. During development of the procedures, depleted electrorefining anodes were processed, and over 80% of the plutonium was recovered as high-purity metal in one electrorefining cycle. Over 40 kg of plutonium has been recovered from 55 kg of impure anodes with our procedures. 6 refs., 7 figs., 4 tabs

Recovery of plutonium by pyroredox processing

International Nuclear Information System (INIS)

McNeese, J.A.; Bowersox, D.F.; Christensen, D.C.

1985-01-01

Using pyrochemical oxidation and reduction, we have developed a process to recover the plutonium in impure scrap with less than 95% plutonium. This plutonium metal was further purified by pyrochemical electrorefining. During development of the procedures, depleted electrorefining anodes were processed, and over 80% of the plutonium was recovered as high-purity metal in one electrorefining cycle. Over 40 kg of plutonium has been recovered from 55 kg of impure anodes with our procedures. 6 refs., 2 figs., 5 tabs

The use of calorimetry for plutonium assay

International Nuclear Information System (INIS)

Mason, J.A.

1982-12-01

Calorimetry is a technique for measuring the thermal power of heat-producing substances. The technique may be applied to the measurement of plutonium-bearing materials which evolve heat as a result of alpha and beta decay. A calorimetric measurement of the thermal power of a plutonium sample, combined with a knowledge or measurement of the plutonium isotopic mass ratios of the sample provides a convenient and accurate, non-destructive measure of the total plutonium mass of the sample. The present report provides a description, and an assessment of the calorimetry technique applied to the assay of plutonium-bearing materials. Types and characteristics of plutonium calorimeters are considered, as well as calibration and operating procedures. The instrumentation used with plutonium calorimeters is described and the use of computer control for calorimeter automation is discussed. A critical review and assessment of plutonium calorimetry literature since 1970 is presented. Both fuel element and plutonium-bearing material calorimeters are considered. The different types of plutonium calorimeters are evaluated and their relative merits are discussed. A combined calorimeter and gamma-ray measurement assay system is considered. The design principles of plutonium assay calorimeters are considered. An automatic, computer-based calorimeter control system is proposed in conjunction with a general plutonium assay calorimeter design. (author)

Analytic determination of plutonium in the environment; Determination analytique du plutonium dans l'environnement

Energy Technology Data Exchange (ETDEWEB)

Ballada, J [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1967-07-01

The work described in this report was undertaken with a view to determining the plutonium content in the fall-out from nuclear explosions. In the first part are described in turn the importance of the problems due to the plutonium, the physico-chemical properties of the radioelement and the biological dangers which it presents. A detailed and critical analysis is made of the radio-toxicological determination of the plutonium as reported in the literature prior to this report. The second part consists in the presentation of a judicious choice of techniques making it possible to determine plutonium in air, rain-water, soils and ash. After a detailed description of the measurement equipment and the operational techniques which have been developed, a justification of these techniques is given with particular reference to their sensitivity and specificity. After a brief conclusion concerning the preceding chapters, the results are presented. These are then discussed in the ease of each element in which the plutonium has been determined. This discussion is concluded by a consideration of the importance of the occurrence of fall-out plutonium on problems relating to public health. From a consideration of 200 analyses carried out, it is concluded that the contribution of plutonium to the exposure of populations is still very small compared to that of natural radiation and that due to such fission products as strontium 90. The report includes 63 literature references, 26 figures and 11 tables. (author) [French] Les travaux decrits dans ce memoire ont ete entrepris et eflectues dans le but de mettre en evidence le plutonium des retombees radioactives consecutives aux explosions nucleaires. Dans la premiere partie nous etudions successivement l'importance des problemes poses par le plutonium puis les proprietes physicochimiques du radioelement et les dangers qu'il presente du point de vue biologique. Nous effectuons une analyse detaillee et critique des techniques

Studies on resin degradation products encountered during purification of plutonium by anion exchange

International Nuclear Information System (INIS)

Ramanujam, A.; Dhami, P.S.; Gopalakrishnan, V.; Dhumwad, R.K.

1991-01-01

Among the methods available for the purification of plutonium in Purex process, anion exchange method offers several advantages. However, on repeated use, the resin gets degraded due to thermal, radiolytic and chemical attacks resulting in chemical as well as physical damage. Frequently, plutonium product eluted from such resin contains significant quantities of white precipitates. A few anion exchange resins were leached with 8 M HNO 3 at 60-80degC and the resin degradation products (RDP) in the leach-extract were found to give similar precipitates with tetravalent metal ions like Pu(IV), Th(IV) etc. Tetra propyl ammonium hydroxide in 8 M HNO 3 (TPAN) also gave a white precipitate with plutonium similar to the one found in the elution streams. The results indicate that delinked quaternary ammonium functional groups might be responsible for the formation of precipitate. The characteristics of precipitates Th-RDP, Th-TPAN and that isolated from elution stream have been investigated. In a separate study a tentative formula for Th-RDP compound is proposed. The influence of RDP on the extraction of plutonium and other components in Purex process was studied and it was found that RDP complexes metal ions thus marginally affecting the kd values. A spectrophotometric method has been standardised to monitor the extent of degradation of anion exchange resins which is based on the ability of RDP to reduce the colour intensity of Th-thoron complex. This technique can be used to study the stability of the anion exchange resins. (author). 8 refs., 8 tabs., 5 figs.,

Pyro-oxidation of plutonium spent salts with sodium carbonate

International Nuclear Information System (INIS)

Bourges, G.; Godot, A.; Valot, C.; Devillard, D.

2001-01-01

The purification of plutonium generates spent salts, which are temporarily stored in a nuclear building. A development programme for pyrochemical treatment is in progress to stabilize and concentrate these salts in order to reduce the quantities for long-term disposal. The treatment, inspired by work previously done by LANL, consists of a pyro-oxidation of the salt with sodium carbonate to convert the actinides into oxides, then of a vacuum distillation to separate the oxides from the volatile salt matrix. Pyro-oxidation of NaCl/KCl base spent salts first produces a 'black salt' which contains more than 97% of the initial actinides. XRD analyses indicate PuO 2 as major plutonium species and sodium plutonates or plutonium sub-oxides PuO 2-x can also be identified. Next appears a 'white salt' containing less than 500 ppm of plutonium, which meets the operational criterion for LLW discard. For these salts, the pyro-oxidation process in and of itself is expected to reduce the quantities to be stored on-site by more than one-third. The pyro-oxidation of CaCl 2 /NaCl base americium extraction salts leads to oxides PuO 2 and probably AmO 2 , but the yield of concentration in the black salt is lower and the white salt cannot be discarded as LLW. During vacuum distillation, excess carbonate can dissociate and damage the efficiency of the process. Appropriate chlorine sparging at the end of the oxidation can eliminate this carbonate. (authors)

Precursor of fragment radicals in the radiolysis of normal alkanes. [Gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Isildar, M; Schuler, R H [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA). Dept. of Chemistry

1978-01-01

It is found that the yields of fragment radicals produced in the radiolysis of n-hexane are not significantly affected by the changes in the ion recombination processes that occur when HI is added to the system. From this observation it is concluded that in the radiolysis of normal alkanes, carbon-carbon bond rupture results predominantly either from high energy processes that do not directly involve ionic precursors or, more likely, from the dissociation of the initial ions at very early times (< 10/sup -11/s) before a substantial fraction of the geminate ions undergo neutralization.

Glycoside bond cleavage in the radiolysis of aqueous solutions of methylglycosides and disaccharides

International Nuclear Information System (INIS)

Shadyro, O.I.; Kisel', R.M.

2007-01-01

The kinetics of formation of methylglycoside and disaccharide radiolysis products resulting from the O-glycoside bond cleavage under the action of 137 Cs γ-radiation (0-2.5 kGy radiation doses, 0.28 Gy/s dose rate) was studied, and the yields of these products were determined. It was found that oxygen inhibits these processes. The findings suggest that the fragmentation reaction of C' 2 radicals plays an important role in the formation of carbohydrate degradation products in the radiolysis of aqueous carbohydrate solutions [ru

Spin trapping of cyanoalkyl radicals in the liquid phase γ radiolysis of nitriles

International Nuclear Information System (INIS)

Mao, S.W.; Kevan, L.

1976-01-01

The following radicals have been identified in the liquid phase γ radiolysis of several nitriles by spin trapping with phenyl tert-butyl nitrone: CH 2 CN in acetonitrile, H and CH 3 CHCN(question) in propionitrile, CH(CN) 2 in malononitrile, and H, CN, and CH 2 CH 2 CN in succinonitrile. γ proton splittings are observed for the CH 2 CN and CH(CH) 2 spin adducts. The results are discussed in comparison with solid phase radiolysis data and with alkyl radical spin adduct splittings

Weapons-grade plutonium dispositioning. Volume 4

International Nuclear Information System (INIS)

Sterbentz, J.W.; Olsen, C.S.; Sinha, U.P.

1993-06-01

This study is in response to a request by the Reactor Panel Subcommittee of the National Academy of Sciences (NAS) Committee on International Security and Arms Control (CISAC) to evaluate the feasibility of using plutonium fuels (without uranium) for disposal in existing conventional or advanced light water reactor (LWR) designs and in low temperature/pressure LWR designs that might be developed for plutonium disposal. Three plutonium-based fuel forms (oxides, aluminum metallics, and carbides) are evaluated for neutronic performance, fabrication technology, and material and compatibility issues. For the carbides, only the fabrication technologies are addressed. Viable plutonium oxide fuels for conventional or advanced LWRs include plutonium-zirconium-calcium oxide (PuO 2 -ZrO 2 -CaO) with the addition of thorium oxide (ThO 2 ) or a burnable poison such as erbium oxide (Er 2 O 3 ) or europium oxide (Eu 2 O 3 ) to achieve acceptable neutronic performance. Thorium will breed fissile uranium that may be unacceptable from a proliferation standpoint. Fabrication of uranium and mixed uranium-plutonium oxide fuels is well established; however, fabrication of plutonium-based oxide fuels will require further development. Viable aluminum-plutonium metallic fuels for a low temperature/pressure LWR include plutonium aluminide in an aluminum matrix (PuAl 4 -Al) with the addition of a burnable poison such as erbium (Er) or europium (Eu). Fabrication of low-enriched plutonium in aluminum-plutonium metallic fuel rods was initially established 30 years ago and will require development to recapture and adapt the technology to meet current environmental and safety regulations. Fabrication of high-enriched uranium plate fuel by the picture-frame process is a well established process, but the use of plutonium would require the process to be upgraded in the United States to conform with current regulations and minimize the waste streams

Operating experience of centrifugal contactors used in a third plutonium purification cycle at the Marcoule reprocessing plant

International Nuclear Information System (INIS)

Coste, J.A.; Breschet, C.A.; Delafontaine, G.L.

1991-01-01

Multistage centrifugal contactors of the type SGN-ROBATEL LX 208 NSC are used in a third plutonium cycle at the Marcoule Reprocessing Plant, they have been smooth-running since the commissioning in 1984. The four centrifugal contactors, totalling 32 stages, are used for Extraction. Scrub and Acidic Strip, and a bank of three flat mixer-settlers is used for plutonium blocking, and soda washing of the solvent. The plutonium product, the residual activity of which is less than one microcurie per gram, is diluent washed in a bank of three flat mixer-settlers, before been concentrated in a zirconium evaporator to 200 g. 1 -1

Determination of Uranium plus Plutonium by Alpha spectrometry in different matrix

International Nuclear Information System (INIS)

Equillor, Hugo E.; Campos, Juan M.

2011-01-01

Usually, the determination of alpha emitters by alpha spectrometry is performed with a prior purification of each of the elements to be quantified. In this work, a methodology for the determination of uranium and plutonium isotopes as jointly described, in order to improve analytical processing times and measurement. The method includes purifying uranium and plutonium, and the subsequent electrodeposition for alpha spectrometry measurement. The technique is based on the use of TBP (tributyl phosphate) as extractant and easy to obtain reactants. It is applicable to various matrices, including water, filters and soils. In the conditions described, is applied to small aliquots of approximately 0.5 g of solid. The technique produces high quality electrodeposits. (authors) [es

Recovery studies for plutonium machining oil coolant

International Nuclear Information System (INIS)

Navratil, J.D.; Baldwin, C.E.

1977-01-01

Lathe coolant oil, contaminated with plutonium and having a carbon tetrachloride diluent, is generated in plutonium machining areas at Rocky Flats. A research program was initiated to determine the nature of plutonium in this mixture of oil and carbon tetrachloride. Appropriate methods then could be developed to remove the plutonium and to recycle the oil and carbon tetrachloride. Studies showed that the mixtures of spent oil and carbon tetrachloride contained particulate plutonium and plutonium species that are soluble in water or in oil and carbon tetrachloride. The particulate plutonium was removed by filtration; the nonfilterable plutonium was removed by adsorption on various materials. Laboratory-scale tests indicated the lathe-coolant oil mixture could be separated by distilling the carbon tetrachloride to yield recyclable products

Effects of the radiolysis products of sennoside A on HepG2 and PC-3 cell

International Nuclear Information System (INIS)

Kim, Dong Ho; Jo, Min Ho

2016-01-01

Radiolysis of sennoside A was carried out by gamma irradiation and the anti-cancer activities of the radiolysis product were evaluated. An aqueous solution of sennoside A was exposed to 0.5-3 kGy of gamma irradiation and the radiolysis products were analyzed by HPLC. A fraction of radiolysis product (RLF) of sennoside A was isolated and the RLF was presumed as a rhein-8-β-D-glucoside. The anticancer effect of the RLF was compared with the sennoside and rhein using a in vitro assay system of human prostate cancer cells (PC-3) and human hepatoma HepG2 cells. The cell viability of PC-3 and HepG2 cell was significantly decreased to 12.4±1.2% and 32.4±2.1%, respectively, by the treatment of 0.6 μM of RLF. The sennoside A (range from 0 to 25 μM) had no cytotoxic effect on PC-3 and HepG2 cells, while the rhein had the effect on HepG2 cells with a LD_5_0 at 80 μM

Effects of the radiolysis products of sennoside A on HepG2 and PC-3 cell

Energy Technology Data Exchange (ETDEWEB)

Kim, Dong Ho; Jo, Min Ho [Research Division for Biotechnology, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

2016-11-15

Radiolysis of sennoside A was carried out by gamma irradiation and the anti-cancer activities of the radiolysis product were evaluated. An aqueous solution of sennoside A was exposed to 0.5-3 kGy of gamma irradiation and the radiolysis products were analyzed by HPLC. A fraction of radiolysis product (RLF) of sennoside A was isolated and the RLF was presumed as a rhein-8-β-D-glucoside. The anticancer effect of the RLF was compared with the sennoside and rhein using a in vitro assay system of human prostate cancer cells (PC-3) and human hepatoma HepG2 cells. The cell viability of PC-3 and HepG2 cell was significantly decreased to 12.4±1.2% and 32.4±2.1%, respectively, by the treatment of 0.6 μM of RLF. The sennoside A (range from 0 to 25 μM) had no cytotoxic effect on PC-3 and HepG2 cells, while the rhein had the effect on HepG2 cells with a LD{sub 50} at 80 μM.

Plutonium use in foreign countries (01)

International Nuclear Information System (INIS)

Otagaki, Takao

2002-03-01

European countries and Japan had been implementing the strategy of spent fuel reprocessing in order to use nuclear material to the maximum. Plutonium recovered from reprocessing, however, must be recycle on light water reactors (LWRs) because of considerable delay of fast reactor development. In Europe, much of experience of plutonium recycling have been accumulated until now. Thus, the status of plutonium recycling up to the end of 2001 in France, Germany, The U.K., Belgium, Switzerland and other countries were studied based on the following scope. (1) Basic policy and present status of plutonium recycling in primary countries of France, Germany, The U.K., Belgium, Switzerland, and Sweden which recently appears the move of recycling a part of plutonium. Backend policy and the status of spent fuel management were studied, then integrated analysis and evaluation of the position of plutonium recycling in backend and the status of plutonium recycling development were performed. (2) Plan and experience of Mixed Oxide (MOX) fuel fabrication and reprocessing of spent fuels. The data and information on plan and experience of MOX fuel fabrication and reprocessing in foreign countries were collected. (3) Plutonium inventories. The data and information on plutonium inventories of foreign countries were collected. (author)

Plutonium use in foreign countries (99)

International Nuclear Information System (INIS)

Otagaki, Takao

2000-03-01

European countries and Japan had been implementing the strategy of spent fuel reprocessing in order to use nuclear material to the maximum. Plutonium recovered from reprocessing, however, must be recycle on light water reactors (LWRs) because of considerable delay of fast reactor development. In Europe, much of experience of plutonium recycling have been accumulated until now. Thus, the status of plutonium recycling up to the end of 1999 in France, Germany, The U.K., Belgium, Switzerland and other countries were studied based on the following scope. (1) Basic policy and present status of plutonium recycling in primary countries of France, Germany, The U.K., Belgium, Switzerland, and Sweden which recently appears the move to recycling a part of plutonium backend policy and the status of spent fuel management were studied, then integrated analysis and evaluation of the position of plutonium recycling in backend and the status of plutonium recycling development were performed. (2) Plan and experience of Mixed Oxide (MOX) fuel fabrication and reprocessing of spent fuels. The data and information on plan and experience of MOX fuel fabrication and reprocessing in foreign countries were collected. (3) Plutonium inventories. The data and information on plutonium inventories of foreign counties were collected. (author)

Plutonium use in foreign countries (02)

International Nuclear Information System (INIS)

Otagaki, Takao

2003-02-01

European countries and Japan had been implementing the strategy of spent fuel reprocessing in order to use nuclear material to the maximum. Plutonium recovered from reprocessing, however, must be recycle on light water reactors (LWRs) because of considerable delay of fast reactor development. In Europe, much of experience of plutonium recycling have been accumulated until now. Thus, the status of plutonium recycling up to the end of 2002 in France, Germany, The U.K., Belgium, Switzerland and other countries were studied based on the following scope. (1) Basic policy and present status of plutonium recycling in primary countries of France, Germany, The U.K., Belgium, Switzerland, and Sweden which recently appears the move of recycling a part of plutonium. Backend policy and the status of spent fuel management were studied, then integrated analysis and evaluation of the position of plutonium recycling in backend and the status of plutonium recycling development were performed. (2) Plan and experience of Mixed Oside (MOX) fuel fabrication and reprocessing of spent fuels. The data and information on plan and experience of MOX fuel fabrication and reprocessing in foreign countries were collected. (3) Plutonium inventories. The data and information on plutonium inventories of foreign countries were collected. (author)

Plutonium use in foreign countries. (04)

International Nuclear Information System (INIS)

Otagaki, Takao

2005-03-01

European countries and Japan had been implementing the strategy of spent fuel reprocessing in order to use nuclear material to the maximum. Plutonium recovered from reprocessing, however, must be recycle on light water reactors (LWRs) because of considerable delay of fast reactor development. In Europe, much of experience of plutonium recycling have been accumulated until now. Thus, the status of plutonium recycling up to the end of 2004 in France, Germany, The U.K., Belgium, Switzerland and other countries were studied based on the following scope. (1) Basic policy and present status of plutonium recycling in primary countries of France, Germany, the U.K., Belgium, Switzerland, and Sweden which plans to recycle a limited amount of plutonium: Backend policy and the status of spent fuel management were studied, then integrated analysis and evaluation of the position of plutonium recycling in backend and the status of plutonium recycling development were performed. (2) Plan and experience of Mixed Oxide (MOX) fuel fabrication and reprocessing of spent fuels: The data and information on plan and experience of MOX fuel fabrication and reprocessing in foreign countries were collected. (3) Plutonium inventories: The data and information on plutonium inventories of foreign countries were collected. (author)

Laboratory-scale evaluations of alternative plutonium precipitation methods

International Nuclear Information System (INIS)

Martella, L.L.; Saba, M.T.; Campbell, G.K.

1984-01-01

Plutonium(III), (IV), and (VI) carbonate; plutonium(III) fluoride; plutonium(III) and (IV) oxalate; and plutonium(IV) and (VI) hydroxide precipitation methods were evaluated for conversion of plutonium nitrate anion-exchange eluate to a solid, and compared with the current plutonium peroxide precipitation method used at Rocky Flats. Plutonium(III) and (IV) oxalate, plutonium(III) fluoride, and plutonium(IV) hydroxide precipitations were the most effective of the alternative conversion methods tested because of the larger particle-size formation, faster filtration rates, and the low plutonium loss to the filtrate. These were found to be as efficient as, and in some cases more efficient than, the peroxide method. 18 references, 14 figures, 3 tables

Simultaneous action of external irradiation and products of air radiolysis

International Nuclear Information System (INIS)

Golikov, V.Ya.; Karklinskaya, O.N.; Mikhalev, V.P.; Vorotyntsev, A.P.; Kotov, N.N.

1977-01-01

To study the radiation damage due to the simultaneous effect of the acute ionizing radiation on the organism and the products of air radiolysis-ozone and nitrogen oxides, laboratory experiments were made. The scheme of the irradiation was the following: the acute dynamic effect (per hour) of X-rays at different doses, and nitrogen oxides and ozone with different concentrations. Male mice were exposed to irradiation (dose of 50-1000 rad, for 60 min.). Data obtained (mortality, survival, exponents of the peripheral blood) proved the radioprotective ability of the chemical agents under study. The radioprotective action was most pronounced at high concentrations. The fact proves that the mechanism of the simultaneous action of the products of air radiolysis and X-ray radiation is complex, and further efforts should be made at its investigation

Femtosecond pulse radiolysis based on photocathode electron accelerator

International Nuclear Information System (INIS)

Yoshida, Y.; Yang, Jinfeng; Kondoh, T.; Kozawa, T.; Tagawa, S.

2006-01-01

Pulse radiolysis is a powerful tool for studying chemical kinetics and primary processes or reactions of radiation chemistry. In the pulse radiolysis, a short electron beam, which is almost produced by radio-frequency (RF) electron linear accelerator with energy from a few MeV to a few tens MeV, is used as an irradiative source. The electron-induced reactions or phenomena in matter are analyzed by a short-pulse analyzing light (e.g. synchronized lasers) with the time-resolved stroboscopic technique. The time resolution of pulse radiolysis is not only dependent on the electron bunch length, the analyzing light pulse width, the time jitter between the electron bunch and the analyzing light, but also determined by degradation due to the velocity difference between light and the electron in the sample because of the refractive index. In order to improve the time resolution into femtosecond time region, we have develop a new pulse radiolysis based on a concept of 'Equivalent Velocity Spectroscopy (EVS)' to avoid the degradation of the time resolution caused by the velocity difference between the light and the electron beam in sample. In EVS as shown in Fig.1, a femtosecond electron beam produced by a photocathode electron linear accelerator was used, and a synchronized femtosecond laser was used as the analyzing light source. The electron beam and the laser light were injected into sample with an angle (θ), which is determined by the refractive index (n) of the sample. The electron bunch was also rotated with a same angle to make an overlap of the electron bunch with the laser pulse. The degradation of the time resolution caused by the velocity difference between the light and the electron beam can be calculated as g(L)=L[n/c-1/(vcos θ)], where L is the optical path length and v is the velocity of the electron in sample (we can assume v=c for a few tens MeV electron beam).We can thus obtained g(L)=0 by adjusting the incident angle to cos θ=1/n. However, the rotation

The plutonium danger

International Nuclear Information System (INIS)

Ruiter, W. de

1983-01-01

Nobody can ignore the fact that plutonium is potentially very dangerous and the greatest danger concerning it lies in the spreading of nuclear weapons via nuclear energy programmes. The following seven different attitudes towards this problem are presented and discussed: 1) There is no connection between peaceful and military applications; 2) The problem cannot be prevented; 3) A technical solution must be found; 4) plutonium must be totally inaccessible to countries involved in acquiring nuclear weapons; 5) The use of plutonium for energy production should only occur in one multinational centre; 6) Dogmas in the nuclear industry must be enfeebled; 7) All developments in this area should stop. (C.F.)

Temporal behavior of hydrated electron studied up to 400 deg. C by ultrafast pulse radiolysis and Monte Carlo calculation

International Nuclear Information System (INIS)

Katsumura, Yosuke; Muroya, Yusa; Lin, Mingzhang; Yu, Yan; Mehran, Mostafavi; Sanguanmith, Sunuchakan; Meesungnoen, Jintana; Jay-Gerin, Jean-Paul

2012-09-01

Pulse radiolysis is a very powerful and unique method to observe the transient species and to determine their yields and has been widely used up to now. Since the radiation-induced reactions at elevated temperatures are accelerated, precise measurement becomes difficult by the conventional pulse radiolysis systems. Then, a higher time resolved pulse radiolysis system is highly expected. Recently, an ultrafast pulse radiolysis system has been developed in the University of Tokyo and applied to water radiolysis at elevated temperatures [1]. Temporal behavior of the hydrated electron at elevated temperatures up to 400 deg C has been detected. The time dependent behavior of hydrated electron at elevated temperatures were detected and the latest version of the Monte Carlo simulation code developed at University of Sherbrooke was applied to reproduce the experimental results. From the simulation, it was made clear that the thermalization distance becomes smaller with increasing temperature. In addition, in supercritical water, the initial yield is significantly dependent on density (pressure), which is consistent with our previous evaluation. (authors)

Free radicals generated by radiolysis of aqueous solutions

International Nuclear Information System (INIS)

Schwarz, H.A.

1981-01-01

The free radicals produced in the radiolysis of aqueous solutions span the range of redox potentials from -2.9 to +2.65 volts. The identity and nature of these radicals were discussed. Most of the discussion was results obtained with low LET radiation sources ( 60 Co gamma radiation or electron accelerators). Water radiolysis provides the synthesis of many radicals and radical ions in aqueous solution. The primary radicals, e/sub aq/ - H, OH, are well characterized. The radical population can be made to be 90% pure OH (or O - ) if N 2 O solutions are irradiated, the remaining 10% being H atoms. 55% of the radicals can be converted to H atoms in acid solution or in neutral phosphate solutions(e/sub aq/ - reacts with H 2 PO 4- to produce H). The remaining 45% (OH radicals) are difficult to convert to H by reaction with H 2 , due to the slow rate of the reaction. About 100 atmospheres of H 2 are required to do the conversion in less than 10 - 6 sec. 3 figures, 3 tables. (DP)

Studies on O/M ratio determination in uranium oxide, plutonium oxide and uranium-plutonium mixed oxide

International Nuclear Information System (INIS)

Sampath, S.; Chawla, K.L.

1975-01-01

Thermogravimetric studies were carried out in unsintered and sintered samples of uranium oxide, plutonium oxide and uranium-plutonium mixed oxide under different atmospheric conditions (air, argon and moist argon/hydrogen). Moisture loss was found to occur below 200 0 C for uranium dioxide samples, upto 700 0 C for sintered plutonium dioxide and negligible for sintered samples. The O/M ratios for non-stoichiometric uranium dioxide (sintered and unsintered), plutonium dioxide and mixed uranium and plutonium oxides (sintered) could be obtained with a precision of +- 0.002. Two reference states UOsub(2.000) and UOsub(2.656) were obtained for uranium dioxide and the reference state MOsub(2.000) was used for other cases. For unsintered plutonium dioxide samples, accurate O/M ratios could not be obtained of overlap of moisture loss with oxygen loss/gain. (author)

Method to manufacture a nuclear fuel from uranium-plutonium monocarbide or uranium-plutonium mononitride

International Nuclear Information System (INIS)

Krauth, A.; Mueller, N.

1977-01-01

Pure uranium carbide or nitride is converted with plutonium oxide and carbon (all in powder form) to uranium-plutonium monocarbide or mononitride by cold pressing and sintering at about 1600 0 C. Pure uranium carbide or uranium nitride powder is firstly prepared without extensive safety measures. The pure uranium carbide or nitride powder can also be inactivated by using chemical substances (e.g. stearic acid) and be handled in air. The sinterable uranium carbide or nitride powder (or also granulate) is then introduced into the plutonium line and mixed with a nonstoichiometrically adjusted, prereacted mixture of plutonium oxide and carbon, pressed to pellets and reaction sintered. The surface of the uranium-plutonium carbide (higher metal content) can be nitrated towards the end of the sinter process in a stream of nitrogen. The protective layer stabilizes the carbide against the water and oxygen content in air. (IHOE) [de

The extraction neptunium by trilaurylamine; L'extraction du neptunium par le trilaurylamine

Energy Technology Data Exchange (ETDEWEB)

Champion, J.; Chesne, A. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1964-07-01

The extraction by trilaurylamine of neptunium (IV) from nitric acid and sulfuric acid-nitric acid media has been studied with the aim of developing a purification process for this element. Relative to the plutonium-neptunium separation, conditions are given for the oxidation of neptunium (IV) in sulfuric acid-nitric acid medium and data are presented on the stabilisation of the + 4 oxidation state by the organic solvent. Two procedures have been developed for the simultaneous purification of the two actinides. Both are based on the trilaurylamine extraction of the tetravalent nitrate species. The first utilises a constant redox potential fixed by Fe{sup +++} /Fe{sup ++} couple, while in the second, valencies are determined by successive addition of nitrite and ferrous ions. Gram quantities of neptunium 237 has been recovered from plutonium process solution. Alternate procedures are suggested for the chemical processing of irradiated Np{sup 237}. (authors) [French] L'extraction du neptunium par le trilaurylamine en milieu nitrique et sulfonitrique a ete etudiee dans le cadre de la recherche des procedes de purification de cet element. En vue d'effectuer la separation neptunium-plutonium on a precise d'une part les conditions d'oxydation du Np{sup 4+} en milieu sulfonitrique, d'autre part l'influence du solvant sur la stabilite des valences de ces deux elements. Deux procedes de purification simultanee des deux actinides ont ete developpes. Ils sont bases sur l'extraction du nitrate des elements tetravalents dans la trilaury lamine. Dans l'un, la solution a extraire a un potentiel redox fixe par un systeme auxiliaire (Fe{sup +++}/Fe{sup ++}), dans l'autre elle subit dans le meme extracteur des additions successives de nitrite et de fer ferreux. On decrit un essai semi-industriel de recuperation de neptunium 237 a partir de solution provenant de l'usine de production de plutonium de Marcoule. Differents schemas

Radiolysis ob benzene, toluene and phenol aqueous solutions utilizing high energy electron beam

International Nuclear Information System (INIS)

Gonzalez Vanderhaghen, D.E.

1998-01-01

In a search for solutions to environmental pollution problems, radiolysis has proved to be an innovative technique for the removal of organic chemical pollutants in aqueous solution. Radiolysis has shown many advantages over many other techniques, as highly reactive species formed in water by ionizing radiation oxidize organic pollutants breaking down organic molecules to final simple products by oxidation to carbon dioxide and water in a complete oxidation. Our work consisted in doing some experiments in radiolysis with simulated polluted water to help us understand this technique and also develop, in a near future, a project for large scale water treatment. Our project includes the application of a Pelletron type Mexican made Electron Accelerator, which will affirm its capability and usefulness in performing investigation in this field of study. Experiments consisted in treating benzene, toluene and phenol aqueous solutions with an Electron Beam (0.48-0.55 MeV; 24 μA). Two concentrations were used for each compound: 5 and 20 ppm (mg/l) for benzene and toluene; 10 and 50 ppm for phenol. Solutions were prepared with pure, mineral free water and two different p H (5.9), in order to study the effect of concentration and p H on removal efficiency, but avoiding the interference of radical scavengers. Results obtained coincide with the ones reported by Cooper, Nickelsen and Kurucz; highly efficient removal was achieved for benzene (>99.8%), toluene (>98.0%) and phenol (>88%). There was no visible important effect of p H on radiolysis efficiency for benzene nor toluene, phenol however, showed lower removal efficiency in acidic conditions. Concentration of aqueous solutions, nevertheless, did show an important effect at low doses for phenol. Results obtained reveal the importance of this technique in water pollution control and water remedial as expressed by Cooper, Nickelsen and Kurucz, who have studied radiolysis of organic compounds and apply this technique in water

Gas phase radiolysis and vacuum ultraviolet photolysis of heterocyclic organic compounds. Progress report, February 1, 1974--February 1, 1975

International Nuclear Information System (INIS)

Scala, A.A.; Salomon, D.; Colon, I.; D'Angona, J.

1975-01-01

In the γ radiolysis of tetrahydrofuran there are pronounced density effects in the pressure range from 0 to 50 Torr with the most important ion-pair yields decreasing as the pressure increases. The relative product yields of the radiolysis is compared with that of xenon photolysis. Possible mechanisms to explain the results obtained are discussed. The ion-pair yields from the γ radiolysis of the heterocyclic amines, ethylenimine, azetidine, pyrrolidine, and piperidine, are determined, and the pressure effects are evaluated. Reactions mechanisms are discussed. The vacuum ultraviolet photolysis products of thietane and tetrahydrothiophene are studied and compared with the γ radiolysis products. Reaction mechanisms are discussed. The status of the construction of a photoionization mass spectrometer and the measurement of the ionization efficiencies and extinction coefficients of organic compounds is reported. (U.S.)

Monitoring the risks of plutonium

International Nuclear Information System (INIS)

Holliday, B.

1978-01-01

The difficulties in monitoring the environment in work areas where plutonium is handled are identified and both continuous and personal air sampling techniques considered. Methods of estimating the amounts of plutonium retained in the body are: (1) Direct external counting over the chest of the 'soft' low energy X-rays and gamma rays emitted by the plutonium deposited in the lungs. (2) Measuring plutonium excreted in urine. (3) Analysing faeces soon after a suspected contamination. Limitation of these techniques are discussed and it is shown that estimating the amount of plutonium in the body, or a specific organ, is extremely difficult, both because of the lack of sensitivity of the measuring techniques (especially chest scanning) and because of the problems in interpreting data, stemming from a lack of knowledge of crucial characteristics of the inhaled plutonium (such as particle size and solubility). Nevertheless it is felt that the judicious integration of all the options creates a level of certainty that no individual technique can possibly inspire. (U.K.)

Progress on plutonium stabilization

Energy Technology Data Exchange (ETDEWEB)

Hurt, D. [Defense Nuclear Facilities Safety Board, Washington, DC (United States)

1996-05-01

The Defense Nuclear Facilities Safety Board has safety oversight responsibility for most of the facilities where unstable forms of plutonium are being processed and packaged for interim storage. The Board has issued recommendations on plutonium stabilization and has has a considerable influence on DOE`s stabilization schedules and priorities. The Board has not made any recommendations on long-term plutonium disposition, although it may get more involved in the future if DOE develops plans to use defense nuclear facilities for disposition activities.

Progress on plutonium stabilization

International Nuclear Information System (INIS)

Hurt, D.

1996-01-01

The Defense Nuclear Facilities Safety Board has safety oversight responsibility for most of the facilities where unstable forms of plutonium are being processed and packaged for interim storage. The Board has issued recommendations on plutonium stabilization and has has a considerable influence on DOE's stabilization schedules and priorities. The Board has not made any recommendations on long-term plutonium disposition, although it may get more involved in the future if DOE develops plans to use defense nuclear facilities for disposition activities

Solid state radiolysis of sulphur-containing amino acids. Cysteine, cystine and methionine

International Nuclear Information System (INIS)

Franco Cataldo; Pietro Ragni; Susana Iglesias-Groth; Arturo Manchado

2011-01-01

The sulphur-containing proteinaceous amino acids l-cysteine, l-cystine and l-methionine were irradiated in the solid state to a dose of 3.2 MGy. This dose corresponds to that delivered by radionuclide decay in a timescale of 1.05 x 10 9 years to the organic matter buried at a depth >20 m in comets and asteroids. The purity of the sulphur-containing amino acids was studied by differential scanning calorimetry (DSC) before and after the solid state radiolysis and the preservation of the chirality after the radiolysis was studied by chirooptical methods (optical rotatory dispersion, ORD) and by FT-IR spectroscopy. Although the high radiation dose of 3.2 MGy delivered, all the amino acids studied show a high radiation resistance. The best radiation resistance was offered by l-cysteine. The radiolysis of l-cysteine leads to the formation of l-cystine. The radiation resistance of l-methionine is not at the level of l-cysteine but also l-methionine is able to survive the dose of 3.2 MGy. Furthermore in all cases examined the preservation of chirality after radiolysis was clearly observed by the ORD spectroscopy although a certain level of radioracemization was measured in all cases. The radioracemization is minimal in the case of l-cysteine and is more pronounced in the case of l-methionine. In conclusion, the study shows that the sulphur-containing amino acids can survive for 1.05 x 10 9 years and, after extrapolation of the data, even to the age of the Solar System i.e. to 4.6 x 10 9 years. (author)

Excess Weapons Plutonium Immobilization in Russia

International Nuclear Information System (INIS)

Jardine, L.; Borisov, G.B.

2000-01-01

The joint goal of the Russian work is to establish a full-scale plutonium immobilization facility at a Russian industrial site by 2005. To achieve this requires that the necessary engineering and technical basis be developed in these Russian projects and the needed Russian approvals be obtained to conduct industrial-scale immobilization of plutonium-containing materials at a Russian industrial site by the 2005 date. This meeting and future work will provide the basis for joint decisions. Supporting R and D projects are being carried out at Russian Institutes that directly support the technical needs of Russian industrial sites to immobilize plutonium-containing materials. Special R and D on plutonium materials is also being carried out to support excess weapons disposition in Russia and the US, including nonproliferation studies of plutonium recovery from immobilization forms and accelerated radiation damage studies of the US-specified plutonium ceramic for immobilizing plutonium. This intriguing and extraordinary cooperation on certain aspects of the weapons plutonium problem is now progressing well and much work with plutonium has been completed in the past two years. Because much excellent and unique scientific and engineering technical work has now been completed in Russia in many aspects of plutonium immobilization, this meeting in St. Petersburg was both timely and necessary to summarize, review, and discuss these efforts among those who performed the actual work. The results of this meeting will help the US and Russia jointly define the future direction of the Russian plutonium immobilization program, and make it an even stronger and more integrated Russian program. The two objectives for the meeting were to: (1) Bring together the Russian organizations, experts, and managers performing the work into one place for four days to review and discuss their work with each other; and (2) Publish a meeting summary and a proceedings to compile reports of all the

Plutonium use - Present status and prospects

International Nuclear Information System (INIS)

Dievoet, J. van; Fossoul, E.; Jonckheere, E.; Bemden, E. van den

1977-01-01

The use of plutonium in thermal and fast reactors is a demonstrated, if not proven, technology. Moreover, plutonium is being produced in increasing quantities. Evaluation of this production on a world scale shows that it would be theoretically possible to construct numerous breeders and thus to make the best use of plutonium, while considerably reducing uranium consumption. This source of plutonium is nevertheless dependent on the reprocessing of irradiated fuel. Long delays in installing and adequate world reprocessing capacity are weakening the prospects for introducing breeders. Furthermore, the critical situation regarding reprocessing may delay the development of complementary reprocessing methods for fuels with a high plutonium content and high burnup. The recycling of plutonium is now a well-known technique and any objections to it hardly bear analysis. Utilization of plutonium offers an appreciable saving in terms of uranium and separative work units; and it can also be shown that immediate reprocessing of the recycling fuel is not essential for the economics of the concept. Temporary storage of recycled fuel is a particularly safe form of concentrating plutonium, namely in irradiated plutonium-bearing fuel assemblies. Finally, recycling offers such flexibility that it represents no obstacle to fuel management at power plants with light-water reactors. These strategic considerations imply that the technology of using plutonium for fabricating thermal or fast reactor fuels is both technically reliable and economically viable. The methods used in industrial facilities are fully reassuring in this respect. Although various unsolved problems exist, none seems likely to impede current developments, while the industrial experience gained has enabled the economics and reliability of the methods to be improved appreciably. Apart from the techno-economic aspects, the plutonium industry must face extremely important problems in connection with the safety of personnel

Dynamics of mobile form of plutonium isotopes in soils within 10-km zone of Chernobyl NPP

International Nuclear Information System (INIS)

Shuktomova, I.I.

1996-01-01

The dynamics of the mobile forms of plutonium isotopes depending on the time of there presence in environment were studied on samples of five soil varieties within the limits of the 10-km zone of Chernobyl NPP. Seasonal dynamic study of the extracted plutonium isotopes showed the increase (5-10 fold) in the amount of mobile forms of radionuclides in all soil samples. Studying the dynamics of total sum of mobile forms of isotopes in soils showed their decrease in general

Solubility of plutonium from rumen contents of cattle grazing on plutonium-contaminated desert vegetation in in vitro bovine gastrointestinal fluids

International Nuclear Information System (INIS)

Barth, J.

1975-01-01

Rumen contents of cattle grazing on plutonium-contaminated desert vegetation at the Nevada Test Site were incubated in simulated bovine gastrointestinal fluids to study the alimentary solubility of plutonium. Trials were run during November 1973, and during February, May, July and August 1974. During the May and July trials, a large increase in plutonium solubility accompanied by a marked reduction in plutonium concentration of the rumen contents was observed concurrently with a reduction in intake of Eurotia lanata and an increase in the intake of Oryzopsis hymenoides or Sitanion jubatum. However, during the November, February, and August trials, comparatively high concentration of plutonium, but low plutonium solubility, was associated with high levels of Eurotia lanata in the rumen contents. Plutonium-238 was generally more soluble than plutonium-239 in these fluids. Ratios of the percentage of soluble plutonium-238 to the percentage of soluble plutonium-239 varied fro []1:1 to 18:1 on a radioactivity basis. (auth)