Status of determining transuranic nuclides speciation in aqueous solution with laser spectrometry

International Nuclear Information System (INIS)

Wang Bo; Liu Dejun; Yao Jun; Chen Xi; Long Haoqi; Zeng Jishu; Su Xiguang; Fan Xianhua

2007-01-01

The knowledge about speciation of transuranic nuclides in aqueous solution is a basis for understanding the chemical and migration behavior of transuranic nuclides in aqueous solution. The speciation of transuranic nuclides with trace concentration is complicated in near neutral aqueous solutions, including change of oxidation state, complexation and colloid generation, etc. The concentrations of transuranium in near neutral aqueous solution usually below the sensitivity range of method such as conventional absorption spectroscopy. The radioactive analysis method has a very low detection limits for radionuclides, however, it wouldn' t allow the direct measurement of the transuranic species. In contrast with these methods, laser spectroscopy is an ideal method with high sensitivity, and non-contact and non-destructive for determining the speciation of transuranic nuclides. This paper summarizes the status and application of LIPAS (Laser-induced Photoacoustic Spectrometry), LIBD (Laser-induced Breakdown Detection) and TRLFS (Time-resolved Laser Fluorescence Spectrometry) to determine the speciation of transuranic nuclides with trace concentration in aqueous solutions. (authors)

Methods and systems for detection of radionuclides

Science.gov (United States)

Coates, Jr., John T.; DeVol, Timothy A.

2010-05-25

Disclosed are materials and systems useful in determining the existence of radionuclides in an aqueous sample. The materials provide the dual function of both extraction and scintillation to the systems. The systems can be both portable and simple to use, and as such can beneficially be utilized to determine presence and optionally concentration of radionuclide contamination in an aqueous sample at any desired location and according to a relatively simple process without the necessity of complicated sample handling techniques. The disclosed systems include a one-step process, providing simultaneous extraction and detection capability, and a two-step process, providing a first extraction step that can be carried out in a remote field location, followed by a second detection step that can be carried out in a different location.

Process for encapsulating radionuclides

International Nuclear Information System (INIS)

Brownell, L.E.; Isaacson, R.E.

1976-01-01

Radionuclides are immobilized in virtually an insoluble form by reacting at a temperature of at least 90 0 C as an aqueous alkaline mixture having a solution pH of at least 10, containing a source of silicon, the radionuclide waste, and a metal cation. The molar ratio of silicon to the metal cation is on the order of unity to produce a gel from which complex metalosilicates crystallize to entrap the radionuclides within the resultant condensed crystal lattice. The product is a silicious stone-like material which is virtually insoluble and nonleachable in alkaline or neutral environment. One embodiment provides for the formation of the complex metalo-silicates, such as synthetic pollucite, by gel formation with subsequent calcination to the solid product; another embodiment utilizes a hydrothermal process, either above ground or deep within basalt caverns, at greater than atmospheric pressures and a temperature between 90 and 500 0 C to form complex metalo-silicates, such as strontium aluminosilicate. Another embodiment provides for the formation of complex metalo-silicates, such as synthetic pollucite, by slurrying an alkaline mixture of bentonite or kaolinite with a source of silicon and the radionuclide waste in salt form. In each of the embodiments a mobile system is achieved whereby the metalo-silicate constituents reorient into a condensed crystal lattice forming a cage structure with the condensed metalo-silicate lattice which completely surrounds the radionuclide and traps the radionuclide therein; thus rendering the radionuclide virtually insoluble

Radionuclide migration test using undisturbed aerated soil

International Nuclear Information System (INIS)

Yamamoto, Tadatoshi; Ohtsuka, Yoshiro; Ogawa, Hiromichi; Wadachi, Yoshiki

1988-01-01

As one of the most important part of safety assessment on the shallow land disposal of lowlevel radioactive waste, the radionuclide migration was studied using undisturbed soil samples, in order to evaluate an exact radionuclide migration in an aerated soil layer. Soil samples used in the migration test were coastal sand and loamy soil which form typical surface soil layers in Japan. The aqueous solution containing 60 CoCl 2 , 85 SrCl 2 and 137 CsCl was fed into the soil column and concentration of each radionuclide both in effluent and in soil was measured. Large amount of radionuclides was adsorbed on the surface of soil column and small amount of radionuclides moved deep into the soil column. Difference in the radionuclide profile was observed in the low concentration portion particularly. It is that some fractions of 60 Co and 137 Cs are stable in non-ionic form and move downward through the soil column together with water. The radionuclide distribution in the surface of soil column can be fairly predicted with a conventional migration equation for ionic radionuclides. As a result of radionuclide adsorption, both aerated soil layers of coastal sand and loamy soil have large barrier ability on the radionuclide migration through the ground. (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)

Biogenic transformed floating macroporous cryogel for uranium sorption from aqueous medium

International Nuclear Information System (INIS)

Tripathi, Anuj; Melo, Jose Savio

2015-01-01

Radionuclide contamination to the environment affects human health and environmental flora and fauna. A recent study suggests that approximately 9000 tons of uranium is contributed to sea every year by fresh water streams and approximately 4.58 billion tons of uranium is present in the well-mixed upper surface of oceans. However, from this around 2 billion tons is considered for accessible recovery. Considering the requirement of separation approaches, a wide range of methods like solvent extraction, ion exchange, complexation and precipitation have been developed for the removal of hazardous substances from water bodies. The process of adsorption using biomaterials is considered as one of the alternative approach for removal of radionuclides from aqueous streams. Authors interest is to develop a simple and user-friendly technology for the separation of radionuclides from aqueous subsurfaces

Accumulation of zirconium phosphate by a Serratia sp.: a benign system for the removal of radionuclides from aqueous flows.

Science.gov (United States)

Mennan, Claire; Paterson-Beedle, Marion; Macaskie, Lynne E

2010-10-01

Metal phosphate deposited enzymatically on Serratia sp. has been used successfully for the removal of radionuclides from aqueous flows. Previous studies using biogenic hydrogen uranyl phosphate (HUP) on Serratia sp. biofilm showed removal of 100% of (90)Sr, (137)Cs, and (60)Co via their intercalation into biogenic HUP crystals. Zirconium phosphates (ZrP) offer a potential non-toxic and non-radioactive alternative to HUP for water decontamination. A method was developed for biomanufacturing ZrP. Biogenic ZrP removed ca. 100% of Sr(2+) and Co(2+) (0.5 mM) from solutions to a molar ratio at saturation of ca. 1:0.6 for both Zr:Sr and Zr:Co. The potential for drinking water decontamination via bio-ZrP is discussed with respect to bio-HUP and also other commercially available materials.

Preparation, characterization and application of superparamagnetic iron oxide nanoparticles modified with natural polymers for removal of {sup 60}Co-radionuclides from aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Sharaf El-Deen, Gehan E. [Atomic Energy Authority, Cairo (Egypt). Radioactive Waste Management Dept.; Imam, Neama G. [Atomic Energy Authority, Cairo (Egypt). Experimental Physics Dept.; Elettra, Sincrotrone, Trieste (Italy); Ayoub, Refaat R. [Atomic Energy Authority, Cairo (Egypt). Nuclear Chemistry Dept.

2017-04-01

Superparamagnetic iron oxide nanoparticles (IO-MNPs) coated with natural polymers, starch (IO-S MNPs) and dextrin (IO-D MNPs), were synthesized by modified co-precipitation method. IO and hybrid-IO-MNPs were characterized by XRD, SEM, HRTEM, FT-IR spectroscopy, vibrating sample magnetometer (VSM) and zeta potential (ZP). IO-S MNPs and IO-D MNPs have IO core-shell structure with core of 10.8 nm and 13.8 nm and shell of 7.5 nm and 5.9 nm, respectively. The efficiency of the hybrid IO-MNPs for sorption of {sup 60}Co(II)-radionuclides from aqueous solution was investigated under varying experimental conditions. Kinetic data were described well by pseudo-second-order mode, sorption isotherms were fitted quite with Freundlich model with maximum adsorption capacity 36.89 (mmol.g{sup -1})/(L.mmol{sup -1}){sup n} for IO-S MNPs and 24.9 (mmol.g{sup -1})/(L.mmol{sup -1}){sup n} for IO-D MNPs. Sorption of {sup 60}Co-radionuclides by IO-S MNPs was suppressed with salinity and most of the adsorbed {sup 60}Co onto IO-S MNPs could be remove with 0.1 M HCl solution. IO-S MNPs exhibits superparamagnetic properties, easier separation according to higher saturation magnetization (47 emu/g) and better adsorption for {sup 60}CO-radionuclides than IO-D MNPs.

Advances in process research by radionuclide techniques

International Nuclear Information System (INIS)

Merz, A.; Vogg, H.

1978-01-01

Modifications and transformations of materials and their technical implementation in process systems require movement of materials. Radionuclide techniques can greatly help in understanding and describing these mechanisms. The specialized measuring technique is demonstrated by three examples selected from various fields of process technology. Radioactive tracer studies performed on a rotary kiln helped, inter alia, to establish a subdivision into process zones and to pinpoint areas of dust generation. Mixing and feeding actions were studied in a twin screw extruder equipped with a special screw and mixer disk arrangement. Tracer experiments conducted in two secondary settling basins indicate the differences in the mechanisms of movement of the aqueous phase if the mean residence time and the residence time distribution may be influenced not only by hydraulic loads, but also by design variants of the overflow flumes. (orig./HP) [de

Decontamination of organic wastes containing radionuclides

International Nuclear Information System (INIS)

Unsworth, T.J.; Pimblott, S.M.; Brown, N.W.

2015-01-01

An electrochemical oxidation treatment has been developed by Arvia Technology for organic wastes containing radionuclides, in which GIC-bisulphate is used as an adsorbent and electrode. Significant work has been carried out in the irradiation of graphite for medical and nuclear applications and in the use of carbonaceous adsorbents but knowledge of the applicability of graphite intercalation compounds (GICs) in these roles is limited. This project will attempt to fill this gap. It will investigate the suitability of GIC-bisulphate as an adsorbent in an electrochemical treatment process for radioactive organic liquids. The process was initially used to treat waste-water from non-nuclear operations and now requires technical knowledge and research to adapt the treatment for the nuclear industry. Adsorption processes involving organic wastes containing mobile radionuclides such as 137 Cs are difficult to understand. The effects of gamma radiation on the chemistry of water and organics could complicate the treatment process further. To ensure the suitability and effectiveness of the electrochemical oxidation treatment for radioactive organic wastes, the following effects are being investigated: -) radiolytic degradation of GIC-bisulphate in solution, -) leaching of intercalated ions due to gamma radiation, -) effect of gamma radiation on the adsorption of organics by GIC-bisulphate, -) changes in the sorption behaviour of radioactive contaminants, -) distribution coefficients of contaminants in organic and aqueous phases, and -) selective or competitive adsorption on graphite surface sites

Coordination polymers: trapping of radionuclides and chemistry of tetravalent actinides (Th, U) carboxylates

International Nuclear Information System (INIS)

Falaise, Clement

2014-01-01

The use of nuclear energy obviously raises the question of the presence of radionuclides in the environment. Currently, their mitigation is a major issue associated with nuclear chemistry. This thesis focuses on both the trapping of radionuclides by porous solids called Metal-Organic Frameworks (MOF) and the crystal chemistry of the carboxylate of tetravalent actinides (AnIV). The academic knowledge of the reactivity of carboxylate of AnIV could help the understanding of actinides speciation in environment. We focused on the sequestration of iodine by aluminum based MOF. The functionalization (electron-donor group) of the MOF drastically enhances the iodine capture capacity. The removal of light actinides (Th and U) from aqueous solution was also investigated as well as the stability of (Al)-MOF under γ radiation. More than twenty coordination polymers based on tetravalent actinides have been synthesized and characterized by single crystal X-ray diffraction. The use of controlled hydrolysis promotes the formation of coordination polymers exhibiting polynuclear cluster ([U 4 ], [Th 6 ], [U 6 ] and [U 38 ]). In order to understand the formation of the largest cluster, the ex-situ study of the solvo-thermal synthesis of compound {U 38 } has also been investigated. (author)

Radionuclide release rates from spent fuel for performance assessment modeling

International Nuclear Information System (INIS)

Curtis, D.B.

1994-01-01

In a scenario of aqueous transport from a high-level radioactive waste repository, the concentration of radionuclides in water in contact with the waste constitutes the source term for transport models, and as such represents a fundamental component of all performance assessment models. Many laboratory experiments have been done to characterize release rates and understand processes influencing radionuclide release rates from irradiated nuclear fuel. Natural analogues of these waste forms have been studied to obtain information regarding the long-term stability of potential waste forms in complex natural systems. This information from diverse sources must be brought together to develop and defend methods used to define source terms for performance assessment models. In this manuscript examples of measures of radionuclide release rates from spent nuclear fuel or analogues of nuclear fuel are presented. Each example represents a very different approach to obtaining a numerical measure and each has its limitations. There is no way to obtain an unambiguous measure of this or any parameter used in performance assessment codes for evaluating the effects of processes operative over many millennia. The examples are intended to suggest by example that in the absence of the ability to evaluate accuracy and precision, consistency of a broadly based set of data can be used as circumstantial evidence to defend the choice of parameters used in performance assessments

Application of biomass for the sorption of radionuclides from low level Purex aqueous wastes

International Nuclear Information System (INIS)

Ramanujam, A.; Gopalakrishnan, V.; Dhami, P.S.; Kannan, R.; Udupa, S.R.; Salvi, N.A.

1997-05-01

Microbial biomass have been found to be good biological adsorbents for radioactive nuclides such as uranium and thorium with comparatively easy desorption and recovery. Based on this, sorption studies have been carried out to assess the feasibility of using biomass Rhizopus arrhizus (RA) for the removal of radionuclides present in Purex low level waste streams. Biomass Rhizopus arrhizus (RA) appears effective for the removal of actinides and fission products from low level Purex plant waste/effluent solutions. Maximum sorption for uranium and plutonium is observed at 6-7 pH whereas for Am, Eu, Pm, Ce and Zr the sorption is maximum at pH 2 with high D values and fast kinetics in both cases. Sorption for Ru and Cs are negligible. Sorbed nuclides are recoverable by elution with 1 M HNO 3 , on once through basis. The method can be used for treating the evaporator condensates from the plant and the hold-up delay tank solution. The sodium nitrate salt concentration in the aqueous solution beyond 0.14 M seriously affects the metal uptake. The results from column experiments indicate a limited loading capacity in terms of mg of Am/U/Pu etc. per gm of RA. However, as the Purex low level effluents contain only trace level activities whose absolute ionic concentrations are much lower, the capacities observed with the present form of biomass may still be satisfactory

A study on the radionuclide transport by bacteria in geologic media

International Nuclear Information System (INIS)

Han, Byoung Sub

1997-02-01

The purpose of this paper is to provide a methodology to develop a predictive model based on a conceptual three phase system and to investigate the influence of bacteria and their generation on the transport of radionuclide in porous and fractured media. The mass balance for bacteria, substrate and radionuclide were formulated. To illustrate the model simply, an equilibrium condition was assumed to partition the substrate, bacteria and radionuclide concentrations between the solid soil matrix, aqueous phase, rock matrix and bacterial surface. From the numerical calculation of the radionuclide transport in the presence of bacteria, it was found that the growth of bacteria and supplied primary substrate as limiting or stimulating growth factor of bacteria are the most important factors of the radionuclide transport. We also found that, depend on the transport of bacteria the temporal and spatial distribution of radionuclide concentration was significantly altered. The model proposed in this study will improve the evaluation of the role of the bacteria in the transport of radionuclide in groundwater systems. Furthermore, this model would be usefully utilized in analyzing the important role of colloidal particulate on the overall performance of radioactive waste safety

Review of radionuclide source terms used for performance-assessment analyses

International Nuclear Information System (INIS)

Barnard, R.W.

1993-06-01

Two aspects of the radionuclide source terms used for total-system performance assessment (TSPA) analyses have been reviewed. First, a detailed radionuclide inventory (i.e., one in which the reactor type, decay, and burnup are specified) is compared with the standard source-term inventory used in prior analyses. The latter assumes a fixed ratio of pressurized-water reactor (PWR) to boiling-water reactor (BWR) spent fuel, at specific amounts of burnup and at 10-year decay. TSPA analyses have been used to compare the simplified source term with the detailed one. The TSPA-91 analyses did not show a significant difference between the source terms. Second, the radionuclides used in source terms for TSPA aqueous-transport analyses have been reviewed to select ones that are representative of the entire inventory. It is recommended that two actinide decay chains be included (the 4n+2 ''uranium'' and 4n+3 ''actinium'' decay series), since these include several radionuclides that have potentially important release and dose characteristics. In addition, several fission products are recommended for the same reason. The choice of radionuclides should be influenced by other parameter assumptions, such as the solubility and retardation of the radionuclides

The physical and chemical environment and radionuclide migration in a low level radioactive waste repository

International Nuclear Information System (INIS)

Torok, J.; Buckley, L.P.

1988-01-01

The expected physical and chemical environment within the low-level radioactive waste repository to be sited at Chalk River is being studied to establish the rate of radionuclide migration. Chemical conditions in the repository are being assessed for their effect on buffer performance and the degradiation of the concrete structure. Experimental programs include the effect of changes in solution chemistry on radionuclide distribution between buffer/backfill materials and the aqueous phase; the chemical stability of the buffer materials and the determination of the controlling mechanism for radionuclide transport during infiltration

COLLAGE: a numerical code for radionuclide migration through a fractured geosphere in aqueous and colloidal phases

Energy Technology Data Exchange (ETDEWEB)

Grindrod, P.; Brown, R.C.; Nicholas, D.G. [Intera Information Technologies, Henley-on-Thames, Oxfordshire (United Kingdom)

1992-06-01

Describes the COLLAGE model for radionuclide migration. COLLAGE models a one dimensional breakthrough problem for radionuclides in groundwater containing natural colloids. The program is written in FORTRAN 77.

COLLAGE: a numerical code for radionuclide migration through a fractured geosphere in aqueous and colloidal phases

International Nuclear Information System (INIS)

Grindrod, P.; Brown, R.C.; Nicholas, D.G.

1992-06-01

Describes the COLLAGE model for radionuclide migration. COLLAGE models a one dimensional breakthrough problem for radionuclides in groundwater containing natural colloids. The program is written in FORTRAN 77

Application of biomass for the sorption of radionuclides from low level Purex aqueous wastes

Energy Technology Data Exchange (ETDEWEB)

Ramanujam, A; Gopalakrishnan, V; Dhami, P S; Kannan, R [Fuel Reprocessing Div., Bhabha Atomic Research Centre, Mumbai (India); Udupa, S R; Salvi, N A [Bio-Organic Div., Bhabha Atomic Research Centre, Mumbai (India)

1997-05-01

Microbial biomass have been found to be good biological adsorbents for radioactive nuclides such as uranium and thorium with comparatively easy desorption and recovery. Based on this, sorption studies have been carried out to assess the feasibility of using biomass Rhizopus arrhizus (RA) for the removal of radionuclides present in Purex low level waste streams. Biomass Rhizopus arrhizus (RA) appears effective for the removal of actinides and fission products from low level Purex plant waste/effluent solutions. Maximum sorption for uranium and plutonium is observed at 6-7 pH whereas for Am, Eu, Pm, Ce and Zr the sorption is maximum at pH 2 with high D values and fast kinetics in both cases. Sorption for Ru and Cs are negligible. Sorbed nuclides are recoverable by elution with 1 M HNO{sub 3}, on once through basis. The method can be used for treating the evaporator condensates from the plant and the hold-up delay tank solution. The sodium nitrate salt concentration in the aqueous solution beyond 0.14 M seriously affects the metal uptake. The results from column experiments indicate a limited loading capacity in terms of mg of Am/U/Pu etc. per gm of RA. However, as the Purex low level effluents contain only trace level activities whose absolute ionic concentrations are much lower, the capacities observed with the present form of biomass may still be satisfactory. 15 refs., 12 tabs.

Effects of radionuclide decay on waste glass behavior: A critical review

International Nuclear Information System (INIS)

Wronkiewicz, D.J.

1993-12-01

This paper is an extension of a chapter in an earlier report [1] that provides an updated review on the status of radiation damage problems in nuclear waste glasses. This report will focus on radiation effects on vitrified borosilicate nuclear waste glasses under conditions expected in the proposed Yucca mountain repository. Radiation effects on high-level waste glasses and their surrounding repository environment are important considerations for radionuclide immobilization because of the potential to alter the glass stability and thereby influence the radionuclide retentive properties of this waste form. The influence of radionuclide decay on vitrified nuclear waste may be manifested by several changes, including volume, stored energy, structure, microstructure, mechanical properties, and phase separation. Radiation may also affect the composition of aqueous fluids and atmospheric gases in relatively close proximity to the waste form. What is important to the radionuclide retentive properties of the repository is how these radiation effects collectively or individually influence the durability and radionuclide release from the glass in the event of liquid water contact

Organic matter linked radionuclide transport in Boom clay - Phenomenological understanding and abstraction to PA

International Nuclear Information System (INIS)

Maes, N.; Bruggeman, C.; Liu, D.J.; Salah, S.; Van Laer, L.; Wang, L.; Weetjens, E.; Govaerts, J.; Marivoet, J.; Brassinnes, S.

2012-01-01

Document available in extended abstract form only. In the frame of the Belgian research program on long term management of high-level and/or long-lived radioactive wastes coordinated by ONDRAF/NIRAS, plastic clays (i.e., Boom Clay and Ypresian clays) are investigated for their potential to host a deep geological disposal repository for radioactive waste because of, among others, their ability to significantly retard radionuclide releases to the biosphere. The Boom Clay is characterised by the presence of a relatively high amount of dissolved organic matter (DOM, humic substances) which show a strong interaction with a suite of radionuclides (RN) like lanthanides, actinides and transition metals. This interaction with DOM leads in general to an increased mobility of the radionuclide as the OM can act as a colloidal carrier for the radionuclide. Therefore, the quantification and the understanding of the underlying processes are needed for the demonstration of confidence in the host formation to act as a suitable barrier. However, this is not an easy task, given the multitude of processes involved: complexation/colloid formation, sorption, kinetics, filtration, -. In this presentation, we will provide an overview of the research work that leads to a straightforward reactive transport model capturing fairly well the experimental observations. The model can be considered as an intermediate model providing a good basis for further safety abstraction on the one hand and the way to a more detailed phenomenological understanding on the other hand. The research is focussed on the underlying processes that govern speciation, sorption and transport. These underlying processes are investigated in a bottom-up approach, from simple systems to more complex systems. Interpretation is done using thermodynamic based models. Whereas the contribution of Bruggeman et al. focusses mainly on (batch) sorption studies (of trivalent RN), this presentation will provide more details on the

Sorbent application on the base of chitosan for radionuclides separation

International Nuclear Information System (INIS)

Pivarciova, L.

2016-01-01

Radioactive waste contains enormous amounts of radionuclides, which pollute the environment and can cause serious chemical and radiological toxicity threats to lower and higher living organism. Alternative process for the removal of heavy metal ions and radionuclides is sorption, which utilizes various certain natural materials of biological origin. Amino-polysaccharide-based sorbents e.g. chitosan represent suitable materials for binding of metal oxo-anion species because of numerous functional groups -OH and -NH_2 because of their suitable H-bond donor and acceptor sites. The sorbents on the base chitosan prepared through chemical modification were used for removal and separation certain radionuclides from aqueous media. The aim of this work was the study of physicochemical properties of prepared sorbents. The specific surface of sorbents was characterized with BET methods. Point of zero charge was identified with potentiometric titration. The size of particles and shape of sorbents were determined by scanning electron microscope. The sorption experiments for selected radionuclides were conducted under static and dynamic conditions. The effect of various parameters on the sorption "9"9"mTc, "6"0Co and the effect of pH on the separation of radionuclide mixture in the solution were studied. (author)

Understanding transfer modes of radionuclides to plants

International Nuclear Information System (INIS)

Hurtevent, P.

2010-01-01

This article briefly comments recent works performed by the IRSN in order to better quantify the transfer of radionuclides from the environment to plants. Three major processes have been studied: root transfer or uptake, translocation, and organic matter recycling (or contamination recycling). The first one depends on the plant and on the soil where it grows. As far as translocation is concerned, the aerial contamination penetrates the plant through the leaves. The third one occurs when broken branches and leaves which have been contaminated, fall on the ground. Some measurements performed in forests near Chernobyl are evoked

Estimates of the solubilities of waste element radionuclides in waste isolation pilot plant brines: A report by the expert panel on the source term

International Nuclear Information System (INIS)

Hobart, D.E.; Bruton, C.J.; Trauth, K.M.; Anderson, D.R.

1996-05-01

Evaluation of the long-term performance of the WIPP includes estimation of the cumulative releases of radionuclide elements to the accessible environment. Nonradioactive lead is added because of the large quantity expected in WIPP wastes. To estimate the solubilities of these elements in WIPP brines, the Panel used the following approach. Existing thermodynamic data were used to identify the most likely aqueous species in solution through the construction of aqueous speciation diagrams. Existing thermodynamic data and expert judgment were used to identify potential solubility-limiting solid phases. Thermodynamic data were used to calculate the activities of the radionuclide aqueous species in equilibrium with each solid. Activity coefficients of the radionuclide-bearing aqueous species were estimated using Pitzer's equations. These activity coefficients were then used to calculate the concentration of each radionuclide at the 0.1 and 0.9 fractiles. The 0.5 fractile was chosen to represent experimental data with activity coefficient corrections as described above. Expert judgment was used to develop the 0.0, 0.25, 0.75, and 1.0 fractiles by considering the sensitivity of solubility to the potential variability in the composition of brine and gas, and the extent of waste contaminants, and extending the probability distributions accordingly. The results were used in the 1991 and 1992 performance assessment calculations. 68 refs

Estimates of the solubilities of waste element radionuclides in waste isolation pilot plant brines: A report by the expert panel on the source term

Energy Technology Data Exchange (ETDEWEB)

Hobart, D.E. [Sandia National Labs., Albuquerque, NM (United States)]|[Glenn T. Seaborg Inst. for Transactinium Science, Livermore, CA (United States); Bruton, C.J. [Sandia National Labs., Albuquerque, NM (United States)]|[Lawrence Livermore National Lab., CA (United States). Earth Sciences Dept.; Millero, F.J. [Sandia National Labs., Albuquerque, NM (United States)]|[Univ. of Miami, FL (United States). Rosenstiel School of Marine and Atmospheric Science; Chou, I.M. [Sandia National Labs., Albuquerque, NM (United States)]|[Geological Survey, Reston, VA (United States); Trauth, K.M.; Anderson, D.R. [Sandia National Labs., Albuquerque, NM (United States)

1996-05-01

Evaluation of the long-term performance of the WIPP includes estimation of the cumulative releases of radionuclide elements to the accessible environment. Nonradioactive lead is added because of the large quantity expected in WIPP wastes. To estimate the solubilities of these elements in WIPP brines, the Panel used the following approach. Existing thermodynamic data were used to identify the most likely aqueous species in solution through the construction of aqueous speciation diagrams. Existing thermodynamic data and expert judgment were used to identify potential solubility-limiting solid phases. Thermodynamic data were used to calculate the activities of the radionuclide aqueous species in equilibrium with each solid. Activity coefficients of the radionuclide-bearing aqueous species were estimated using Pitzer`s equations. These activity coefficients were then used to calculate the concentration of each radionuclide at the 0.1 and 0.9 fractiles. The 0.5 fractile was chosen to represent experimental data with activity coefficient corrections as described above. Expert judgment was used to develop the 0.0, 0.25, 0.75, and 1.0 fractiles by considering the sensitivity of solubility to the potential variability in the composition of brine and gas, and the extent of waste contaminants, and extending the probability distributions accordingly. The results were used in the 1991 and 1992 performance assessment calculations. 68 refs.

The effect of bacterial generation on the transport of radionuclide in porous media

International Nuclear Information System (INIS)

Han, B.S.; Lee, K.J.

1997-01-01

The purpose of this paper is to provide a methodology to develop a predictive model based on a conceptual three-phase system and to investigate the influence of bacteria and their generation on the radionuclide transport in porous media. The mass balance equations for bacteria, substrate and radionuclide were formulated. To illustrate the model simply, an equilibrium condition was assumed to partition the substrate, bacteria and radionuclide concentrations, between the solid soil matrix, aqueous phase and bacterial surface. From the numerical calculation of radionuclide transport in the presence of bacteria, it was found that the growth of bacterial and supplied primary substrate as a limiting or stimulating growth factor of bacteria are the most important factors of the radionuclide transport. It was also found that, depending on the transport of bacteria, the temporal and spatial distribution of the radionuclide concentration was significantly affected. The model proposed in this study will improve the evaluation of the role of the bacteria to the transport of radionuclide in groundwater systems. Furthermore, this model can be usefully utilized in analyzing the important role of colloidal particulate on the overall performance of radioactive waste safety. (Author)

Mobility and Bioavailability of Radionuclides in Soils

International Nuclear Information System (INIS)

Iurian, A.; Olufemi Phaneuf, M.; Mabit, L.

2016-01-01

It is crucial to understand the behavior of radionuclides in the environment, their potential mobility and bioavailability related to long-term persistence, radiological hazards, and impact on human health. Such key information is used to develop strategies that support policy decisions. The environmental behavior of radionuclides depends on ecosystem characteristics. A given soil’s capacity to immobilize radionuclides has been proved to be the main factor responsible for their resulting activity concentrations in plants. The mobility and bioavailability of radionuclides in soils is complex, depending on clay-sized soil fraction, clay mineralogy, organic matter, cation exchange capacity, pH and quantities of competing cations. Moreover, plant species have different behaviors regarding radionuclide absorption depending on soil and plan characteristics

Innovative methods to stabilize liquid membranes for removal of radionuclides from groundwater

Energy Technology Data Exchange (ETDEWEB)

Lokhandwala, K. [Membrane Technology and Research, Inc., Menlo Park, CA (United States)

1997-10-01

In this Phase I Small Business Innovation Research program, Membrane Technology Research, Inc., is developing a stable liquid membrane for extracting uranium and other radionuclides from groundwater. The improved membrane can also be applied to separation of other metal ions from aqueous streams in industrial operations.

Assessment of Management Oxides for the Sorption of Radionuclides

International Nuclear Information System (INIS)

D.R. Learman; M.F. Hochella, Jr.

2005-01-01

Recent research has shown that certain manganese oxides have the ability to sorb aqueous metal cations much more efficiently than any of the naturally occurring iron oxides when normalized to surface area. This ability is, at least in part, related to the internal sites available in many manganese oxide structures, including those within tunnels and between sheets. Additionally, a new naturally-occurring manganese oxide structurally related to vernadite ((delta)-MnO 2 ), collected along the Clark Fork River in western Montana, USA, has shown the ability to sorb arsenate, an anionic complex. The potential for manganese oxides to sorb anions has made it an attractive material as a radionuclide ''getter''. According to the US Department of Energy's Total Systems Performance Assessment, technetium and iodine are two major anionic radionuclides contributing to the list of potential contaminants released from Yucca Mountain repository, Nevada, USA. These two radionuclides are extremely problematic because they are very mobile in the environment. This project involves running flow-through sorption experiments using rhenium (a surrogate for technetium) and stable iodine as sorbates and several synthetic manganese oxides, including birnessite, vernadite, cryptomelane, and possibly the new vernadite-like phase mentioned earlier, as sorbants. For all synthesis reactions, manganese (VII) salts are reduced to manganese (III,IV) oxides. The different oxides are produced from specific reductants and/or the addition of heat, followed by multiple washing steps. To verify that the proper phases have been synthesized, all oxides are analyzed using transmission electron microscopy (TEM) and powder X-ray diffraction (XRD). The sorption experiments will be run in flow-through reactors bearing the aqueous complex of interest, where solutions, at various temperatures, pH's, and ionic strengths, will pass through a bed of one of the manganese oxides. The effluent solution will be analyzed

The chemical behaviour and ecological transfer in the human food chain of some radionuclides in aqueous ecosystems

International Nuclear Information System (INIS)

Furnica, Gh.

1980-01-01

The aqueous ecosystem of the Danube has been investigated in the period of 1976-1979. Data on the ecological transfer of radionuclides in the human food chain made an estimation available on the risk of the affected population. In the assessment of population exposure, the internal radiation dose for a period of one year and the continuous external irradiation determined by TLD have been considered. - The results revealed very low Sr-90 and Cs-137 contents in the Danube water and in the drinking water. The radioactivity contents are higher in the sediment and in some biota than in the water. The H-3 content in the Danube water varies in a wider range and higher concentration was found in fish than in the water. Both the Danube sediment and the irrigated sandy soil contain very low concentrations of fission products. During 1976-1979, the radioiodine content in air, milk and cow thyroid around the 679-Km is continuously decreasing. - Based on the data obtained, the corresponding collective dose equivalent value was calculated and the risk on the health of the population was found to be very low from contamination during 1975-1978. The radioactivity concentration values in critical human food chain, however, are not negligible. (author)

Techniques for rapid determination of effects of synergy between radionuclides and pollutants

International Nuclear Information System (INIS)

Saas, A.; Grauby, A.

1975-01-01

The authors present a number of chromatographic techniques for rapid determination of synergy between radionuclides and various compounds in water. The first technique consists in studying how the chemical equilibrium of iodine varies in the presence of various organic and mineral compounds. The second makes it possible to define the effects of synergy within a given hydrographic basin. A third technique deals with the effects of synergy in ground water in the presence of various types of irrigation water. Finally, to complete this set of techniques, the authors define the mobility potential of a radionuclide in a given aqueous effluent

Optimization of surveillance methods of water radionuclide intake by man

Energy Technology Data Exchange (ETDEWEB)

Pakulo, A.G. (Institut Biofiziki, Moscow (USSR))

1984-11-01

A method has been suggested to test and sample prepared food stuffs, when studying and analyzing the intake of radionuclides from aqueous food chains to people. The method is characterized by the following advantages: a possibility to establish to a greater accuracy the amount of consumed products, as compared with inquiry method; a possibility to determine the actual radionuclide contents in prepared food without introduction of correcting coefficients for isotope translocation to the ration during culinary treatment of raw food stuff. Different ways of preparation are known to affect differently the degree of isotope translocaton to the ration. The above-mentioned method under certain conditions seems to be handy while excluding preliminary treatment of samples.

Radionuclides in the study of marine processes

International Nuclear Information System (INIS)

Kershaw, P.J.; Woodhead, D.S.

1991-01-01

For many years, the radioactive properties of the naturally occurring radionuclides have been used to determine their distributions in the marine environment and, more generally, to gain an understanding of the dynamic processes which control their behaviour in attaining these distributions. More recently the inputs from human activities of both natural and artificial (i.e. man-made) radionuclides have provided additional opportunities for the study of marine processes on local, regional and global scales. The primary objective of the symposium is to provide a forum for an open discussion of the insights concerning processes in the marine environment which can be gained from studies of radionuclide behaviour. Papers have been grouped within the following principal themes; the uses of radionuclides as tracers of water transport; scavenging and particulate transport processes in the oceans as deduced from radionuclide behaviour; processes in the seabed and radionuclides in biological systems. (Author)

Geochemical effects on the behavior of LLW radionuclides in soil/groundwater environments

Energy Technology Data Exchange (ETDEWEB)

Krupka, K.M.; Sterne, R.J. [Pacific Northwest Lab., Richland, WA (United States)

1995-12-31

Assessing the migration potential of radionuclides leached from low-level radioactive waste (LLW) and decommissioning sites necessitates information on the effects of sorption and precipitation on the concentrations of dissolved radionuclides. Such an assessment requires that the geochemical processes of aqueous speciation, complexation, oxidation/reduction, and ion exchange be taken into account. The Pacific Northwest National Laboratory (PNNL) is providing technical support to the U.S. Nuclear Regulatory Commission (NRC) for defining the solubility and sorption behavior of radionuclides in soil/ground-water environments associated with engineered cementitious LLW disposal systems and decommissioning sites. Geochemical modeling is being used to predict solubility limits for radionuclides under geochemical conditions associated with these environments. The solubility limits are being used as maximum concentration limits in performance assessment calculations describing the release of contaminants from waste sources. Available data were compiled regarding the sorption potential of radionuclides onto {open_quotes}fresh{close_quotes} cement/concrete where the expected pH of the cement pore waters will equal to or exceed 10. Based on information gleaned from the literature, a list of preferred minimum distribution coefficients (Kd`s) was developed for these radionuclides. The K{sub d} values are specific to the chemical environments associated with the evolution of the compositions of cement/concrete pore waters.

Facts and features of radionuclide migration in Boom Clay

International Nuclear Information System (INIS)

De Regge, P.; Henrion, P.; Monsecour, M.; Put, M.

1988-01-01

The evolution which took place during ten years of research on the behaviour of radionuclides in Boom Clay is described. Initially, the Boom Clay was regarded as a chemically inert exchanger and the radiochemical research aimed at determining the distribution of cations between the clay and some liquid phases. The observation that Boom Clay deteriorates in contact with air and loses important intrinsic properties formed a major breakthrough in the research and led to a careful examination of the real in-situ conditions. Efforts devoted to the understanding of the chemical factors pertaining to the pH, the redox potential, the extent of the buffering capacity of FeS 2 and CaCO 3 in equilibrium with the interstitial aqueous phase are reviewed. Also emerging from the overall picture was the role of the organic material present in the Boom Clay. In contrast to the water percolating fractured formations which may not be in equilibrium with the rock, the interstitial aqueous phase is completely in equilibrium with Boom Clay mainly because of its low permeability and the large excesses of buffering components. As the retention mechanisms are better understood, a more coherent picture is obtained from distribution and diffusion experiments and the effects of consolidation are being investigated in detail. 23 refs.; 4 figs.; 3 tabs

Hydrology/Radionuclide Migration Program and related research activities

International Nuclear Information System (INIS)

Jones, M.A.

1992-02-01

This report presents the results of technical studies conducted under the Hydrology/Radionuclide Migration Program (HRMP) at the Nevada Test Site (NTS) for the period of October 1, 1985 through September 30, 1986. The HRMP was initiated in 1973 as the Radionuclide Migration Program to study and better understand the hydrologic systems of the NTS and potential movement and rates of movement of radionuclides and other contaminants injected into these systems by underground nuclear testing

Idaho radionuclide exposure study: Literature review

International Nuclear Information System (INIS)

Baker, E.G.; Freeman, H.D.; Hartley, J.N.

1987-10-01

Phosphate ores contain elevated levels of natural radioactivity, some of which is released to the environment during processing or use of solid byproducts. The effect of radionuclides from Idaho phosphate processing operations on the local communities has been the subject of much research and study. The literature is reviewed in this report. Two primary radionuclide pathways to the environment have been studied in detail: (1) airborne release of volatile radionuclides, primarily 210 Po, from calciner stacks at the two elemental phosphorus plants; and (2) use of byproduct slag as an aggregate for construction in Soda Springs and Pocatello. Despite the research, there is still no clear understanding of the population dose from radionuclide emissions, effluents, and solid wastes from phosphate processing plants. Two other potential radionuclide pathways to the environment have been identified: radon exhalation from phosphogypsum and ore piles and contamination of surface and ground waters. Recommendations on further study needed to develop a data base for a complete risk assssment are given in the report

Modeling Radionuclide Decay Chain Migration Using HYDROGEOCHEM

Science.gov (United States)

Lin, T. C.; Tsai, C. H.; Lai, K. H.; Chen, J. S.

2014-12-01

Nuclear technology has been employed for energy production for several decades. Although people receive many benefits from nuclear energy, there are inevitably environmental pollutions as well as human health threats posed by the radioactive materials releases from nuclear waste disposed in geological repositories or accidental releases of radionuclides from nuclear facilities. Theoretical studies have been undertaken to understand the transport of radionuclides in subsurface environments because that the radionuclide transport in groundwater is one of the main pathway in exposure scenarios for the intake of radionuclides. The radionuclide transport in groundwater can be predicted using analytical solution as well as numerical models. In this study, we simulate the transport of the radionuclide decay chain using HYDROGEOCHEM. The simulated results are verified against the analytical solution available in the literature. Excellent agreements between the numerical simulation and the analytical are observed for a wide spectrum of concentration. HYDROGECHEM is a useful tool assessing the ecological and environmental impact of the accidental radionuclide releases such as the Fukushima nuclear disaster where multiple radionuclides leaked through the reactor, subsequently contaminating the local groundwater and ocean seawater in the vicinity of the nuclear plant.

Effect of gley formation on leaching of radionuclides and toxic metals from soils

International Nuclear Information System (INIS)

Legin, E.K.; Trifonov, Yu.I.; Khokhlov, M.L.; Legina, E.E.; Strukov, V.N.; Kuznetsov, Yu.V.

2002-01-01

Radionuclides and toxic metals, entering the soil as a result of technogenic contamination, are not uniformly distributed throughout the soil body, but preferentially fixed on so-called gel films. The gel films represent colloid formations consisting of primarily amorphous iron hydroxides, coordination polymers of mixed Ca,Fe,Al fulvates and humates, and amorphous silica fixed on the muddy aluminosilicate fraction ( 238 U, 239,240 Pu, 152 Eu, 232 Th, 60 Co) and stable elements (Co, Eu) leached from soil samples directly correlates with that of iron, suggesting that under reducing conditions the drainage solution contains a mixture of iron, radionuclides, and microelements of nearly constant composition. This result is consistent with the existing views that radionuclides and microelements in soils are concentrated in the gel films. Furthermore, it reveal that in the investigated system solubilisation of the gel films is accompanied by a combined transfer of radionuclides and stable microelements to the aqueous phase. The most significant effect of leaching was observed for plutonium. (author)

Uptake by plants of radionuclides from FUSRAP waste materials

International Nuclear Information System (INIS)

Knight, M.J.

1983-04-01

Radionuclides from FUSRAP wastes potentially may be taken up by plants during remedial action activities and permanent near-surface burial of contaminated materials. In order to better understand the propensity of radionuclides to accumulate in plant tissue, soil and plant factors influencing the uptake and accumulation of radionuclides by plants are reviewed. In addition, data describing the uptake of the principal radionuclides present in FUSRAP wastes (uranium-238, thorium-230, radium-226, lead-210, and polonium-210) are summarized. All five radionuclides can accumulate in plant root tissue to some extent, and there is potential for the translocation and accumulation of these radionuclides in plant shoot tissue. Of these five radionuclides, radium-226 appears to have the greatest potential for translocation and accumulation in plant shoot tissue. 28 references, 1 figure, 3 tables

Uptake by plants of radionuclides from FUSRAP waste materials

Energy Technology Data Exchange (ETDEWEB)

Knight, M.J.

1983-04-01

Radionuclides from FUSRAP wastes potentially may be taken up by plants during remedial action activities and permanent near-surface burial of contaminated materials. In order to better understand the propensity of radionuclides to accumulate in plant tissue, soil and plant factors influencing the uptake and accumulation of radionuclides by plants are reviewed. In addition, data describing the uptake of the principal radionuclides present in FUSRAP wastes (uranium-238, thorium-230, radium-226, lead-210, and polonium-210) are summarized. All five radionuclides can accumulate in plant root tissue to some extent, and there is potential for the translocation and accumulation of these radionuclides in plant shoot tissue. Of these five radionuclides, radium-226 appears to have the greatest potential for translocation and accumulation in plant shoot tissue. 28 references, 1 figure, 3 tables.

Radionuclide transport and retardation in tuff

International Nuclear Information System (INIS)

Vine, E.N.; Bayhurst, B.P.; Daniels, W.R.; DeVilliers, S.J.; Erdal, B.R.; Lawrence, F.O.; Wolfsberg, K.

1980-01-01

Batch measurements provide an understanding of which experimental variables are important. For example, sorption ratios vary little with particle size (and surface area); however, groundwater composition and rock composition are quite important. A general correlation has been identified between mineralogy (major phases) and degree of sorption for strontium, cesium, and barium. Although these are approximate, a more detailed analysis may be possible as more samples are studied and the data base increased. Data from crushed tuff columns indicate that, except in simple cases where sorption coefficients are relatively low, and ion-exchange equilibria not only exist but are the dominant mechanism for removal of radioisotopes from solution, the simple relation between the sorption ratio R/sub d/ (or K/sub d/) and the relative velocity of radionuclides with respect to groundwater velocity may be insufficient to permit accurate modeling of the retardation of radionuclides. Additional work on whole core columns and larger blocks of intact material is required to better understand radionuclide sorption and transport through rock

Monitoring dynamics of aqueous humor in glaucoma

International Nuclear Information System (INIS)

Vyborny, P.; Hornova, J.

1985-01-01

Aqueous humor dynamics was observed in patients treated for glaucoma. Aqueous flow was measured using the radionuclide method of contact application of 22 NaCl and the detection of gamma radiation with external detectors. The sample of 184 eyes was divided into three groups: open-angle glaucoma with therapy, open-angle glaucoma without therapy and angle-closure glaucoma 47 eyes were used as controls. Changes were observed in 22 Na outflow half-time in dependence on the duration of the disease, therapy, intraocular pressUre and changes in the perimeter. The new technique has been fully proven in practice, is a contribution to the diagnosis of glaucoma and an indicator of the compensation of the disease. (author)

Aqueous geochemistry in icy world interiors: Equilibrium fluid, rock, and gas compositions, and fate of antifreezes and radionuclides

Science.gov (United States)

Neveu, Marc; Desch, Steven J.; Castillo-Rogez, Julie C.

2017-09-01

The geophysical evolution of many icy moons and dwarf planets seems to have provided opportunities for interaction between liquid water and rock (silicate and organic solids). Here, we explore two ways by which water-rock interaction can feed back on geophysical evolution: the production or consumption of antifreeze compounds, which affect the persistence and abundance of cold liquid; and the potential leaching into the fluid of lithophile radionuclides, affecting the distribution of a long-term heat source. We compile, validate, and use a numerical model, implemented with the PHREEQC code, of the interaction of chondritic rock with pure water and with C, N, S-bearing cometary fluid, thought to be the materials initially accreted by icy worlds, and describe the resulting equilibrium fluid and rock assemblages at temperatures, pressures, and water-to-rock ratios of 0-200 ° C, 1-1000 bar, and 0.1-10 by mass, respectively. Our findings suggest that water-rock interaction can strongly alter the nature and amount of antifreezes, resulting in solutions rich in reduced nitrogen and carbon, and sometimes dissolved H2, with additional sodium, calcium, chlorine, and/or oxidized carbon. Such fluids can remain partially liquid down to 176 K if NH3 is present. The prominence of Cl in solution seems to hinge on its primordial supply in ices, which is unconstrained by the meteoritical record. Equilibrium assemblages, rich in serpentine and saponite clays, retain thorium and uranium radionuclides unless U-Cl or U-HCO3 complexing, which was not modeled, significantly enhances U solubility. However, the radionuclide 40 K can be leached at high water:rock ratio and/or low temperature at which K is exchanged with ammonium in minerals. We recommend the inclusion of these effects in future models of the geophysical evolution of ocean-bearing icy worlds. Our simulation products match observations of chloride salts on Europa and Enceladus; CI chondrites mineralogies; the observation of

Radionuclides in the environment: Risks and opportunities

International Nuclear Information System (INIS)

Elzerman, A.W.

1993-01-01

Environmental chemistry plays a critical role in the open-quotes nuclear ageclose quotes. It makes a vital contribution to understanding of the sources, fate and effects of radionuclides in the environment, both man-made and natural. Risk assessment of radionuclides in the environment relies heavily on the tools of environmental chemistry. On the other hand, radionuclides provide unique opportunities to exploit in environmental chemistry investigations due to their well-defined sources, traceability in environmental processes, analytical sensitivities, and open-quotes built-inclose quotes radioactive decay open-quotes clocksclose quotes. In some cases naturally present radionuclides are utilized, while in others tracers are deliberately added or have already been added by the nuclear fuel cycle or nuclear testing. Several examples in each of these categories are discussed to spotlight the current status of environmental chemistry and radionuclides in the environment as an example application

Biogeochemical Processes Controlling Microbial Reductive Precipitation of Radionuclides

International Nuclear Information System (INIS)

Fredrickson, James K.; Brooks, Scott C.

2004-01-01

This project is focused on elucidating the principal biogeochemical reactions that govern the concentrations, chemical speciation, and distribution of the redox sensitive contaminants uranium (U) and technetium (Tc) between the aqueous and solid phases. The research is designed to provide new insights into the under-explored areas of competing geochemical and microbiological oxidation-reduction reactions that govern the fate and transport of redox sensitive contaminants and to generate fundamental scientific understanding of the identity and stoichiometry of competing microbial reduction and geochemical oxidation reactions. These goals and objectives are met through a series of hypothesis-driven tasks that focus on (1) the use of well-characterized microorganisms and synthetic and natural mineral oxidants, (2) advanced spectroscopic and microscopic techniques to monitor redox transformations of U and Tc, and (3) the use of flow-through experiments to more closely approximate groundwater environments. The results are providing an improved understanding and predictive capability of the mechanisms that govern the redox dynamics of radionuclides in subsurface environments. For purposes of this poster, the results are divided into three sections: (1) influence of Ca on U(VI) bioreduction; (2) localization of biogenic UO 2 and TcO 2 ; and (3) reactivity of Mn(III/IV) oxides.

EOS7R: Radionuclide transport for TOUGH2

International Nuclear Information System (INIS)

Oldenburg, C.M.; Pruess, K.

1995-11-01

EOS7R provides radionuclide transport capability for TOUGH2. EOS7R extends the EOS7 module (water, brine, and optional air) to model water, brine, parent component, daughter component, and optional air and heat. The radionuclide components follow a first-order decay law, and may adsorb onto the solid grains. Volatilization of the decaying components is modeled by Henry's Law. The decaying components are normally referred to as radionuclides, but they may in fact by any trace components that decay, adsorb, and volatilize. The decay process need not be radioactive decay, but could be any process that follows a first-order decay law, such as biodegradation. EOS7R includes molecular diffusion for all components in gaseous and aqueous phases using a simplified binary diffusion model. When EOS7R is used with standard TOUGH2, transport occurs by advection and molecular diffusion in all phases. When EOS7R is coupled with the dispersion module T2DM, one obtains T2DMR, the radionuclide transport version of T2DM. T2DMR models advection, diffusion, and hydrodynamic dispersion in rectangular two-dimensional regions. Modeling of radionuclide transport requires input parameters specifying the half-life for first-order decay, distribution coefficients for each rock type for adsorption, and inverse Henry's constants for volatilization. Options can be specified in the input file to model decay in inactive grid blocks and to read from standard EOS7 INCON files. The authors present a number of example problems to demonstrate application and accuracy of TOUGH2/EOS7R. One-dimensional simulation results agree well with analytical solutions. For a two-dimensional salt-dome flow problem, the final distribution of daughter radionuclide component is complicated by the presence of weak recirculation caused by density effects due to salinity

COLLAGE 2: a numerical code for radionuclide migration through a fractured geosphere in aqueous and colloidal phases

International Nuclear Information System (INIS)

Grindrod, P.; Cooper, N.

1993-05-01

In previous work, the COLLAGE code was developed to model the impacts of mobile and immobile colloidal material upon the dispersal and migration of a radionuclide species within a saturated planer fracture surrounded by porous media. The adsorption of radionuclides to colloid surfaces was treated as instantaneous and reversible. In this report we present a new version of the code, COLLAGE 2. Here the adsorption of radionuclides to the colloidal material is treated via first order kinetics. The flow and geometry of the fracture remain as in the previous model. The major effect of colloids upon the radionuclide species is to adsorb them within the fracture space and thus exclude them from the surrounding porous medium. Thus the matrix diffusion process, a strongly retarding effect, is exchanged for a colloid capture/release process by which adsorbed nuclides are also retarded. The effects of having a colloid-radionuclide kinetic interaction include the phenomena of double pulse breakthrough (the pseudo colloid population followed by the solute plume) in cases where the desorption process is slow and the pseudo colloids are highly mobile. Some example calculations are given and some verification examples are discussed. Finally a complete listing of the code is presented as an appendix, including the subroutines allowing for the numerical inversion of the Laplace transformed solution via Talbot's method. 6 figs

COLLAGE 2: a numerical code for radionuclide migration through a fractured geosphere in aqueous and colloidal phases

Energy Technology Data Exchange (ETDEWEB)

Grindrod, P.; Cooper, N. [Intera Information Technologies Ltd., Henley-on-Thames (United Kingdom)

1993-05-01

In previous work, the COLLAGE code was developed to model the impacts of mobile and immobile colloidal material upon the dispersal and migration of a radionuclide species within a saturated planer fracture surrounded by porous media. The adsorption of radionuclides to colloid surfaces was treated as instantaneous and reversible. In this report we present a new version of the code, COLLAGE 2. Here the adsorption of radionuclides to the colloidal material is treated via first order kinetics. The flow and geometry of the fracture remain as in the previous model. The major effect of colloids upon the radionuclide species is to adsorb them within the fracture space and thus exclude them from the surrounding porous medium. Thus the matrix diffusion process, a strongly retarding effect, is exchanged for a colloid capture/release process by which adsorbed nuclides are also retarded. The effects of having a colloid-radionuclide kinetic interaction include the phenomena of double pulse breakthrough (the pseudo colloid population followed by the solute plume) in cases where the desorption process is slow and the pseudo colloids are highly mobile. Some example calculations are given and some verification examples are discussed. Finally a complete listing of the code is presented as an appendix, including the subroutines allowing for the numerical inversion of the Laplace transformed solution via Talbot`s method. 6 figs.

Study of migration behavior of technogenic radionuclides in the Yenisey River-Kara Sea aquatic system

Energy Technology Data Exchange (ETDEWEB)

Kuznetsov, Yu.; Legin, E.; Legin, V. [Khlopin Radium Institute, St. Petersburg (Russian Federation); Shishlov, A.; Savitskii, Yu. [Krasnoyarsk Mining and Chemical Combine, Krasnoyarsk (Russian Federation); Novikov, A.; Goryachenkova, T. [Russian Academy of Sciences, Institute of Geochemistry and Analytical Chemistry, Moscow (Russian Federation)

2001-03-01

For 35 years Krasnoyarsk Mining-Chemical Combine (MCC) manufactures weapon plutonium in single-pass production reactors cooled with water of the Yenisey River. Water discharge from these reactors is the major source of radioactive contamination of the Yenisey River. We have demonstrated that after putting the reactors out of operation (in late 1992) the contamination level of the Yenisey River with short-lived radionuclides considerably decreased, and now the radioactive contamination is caused essentially by Cs-137, Eu-152, Pu-239,240, Sr-90, and Am-241, whose concentration in the aqueous phase is lower than in bottom sediments and, particularly, flood-land deposits by several orders of magnitude (except for Sr-90). The flood-land deposits are classified with the most contaminated environmental objects in the territories under the impact of MCC: their radioactivity is comparable with that of low-level waste. Taking into account the considerable depth and area of the flood-land deposits, this allows their classification as a great technogenic radiation anomaly. Comparison of the maximal Cs-137 and Pu-239,240 levels in flood-land soils and bottom sediments of the Yenisey River with those in bottom sediments of the Pripyat' River and the Kiev reservoir shows that these values are close each to other. A direct correlation is found between the spatial distribution of Cs-137 on the one hand and Pu-239,240, Eu-152, and Am-241 on the other hand in the aqueous phase and bottom sediments, which is not the case for Sr-90. Data on the distribution coefficients of the indicated radionuclides between the deposits and aqueous phase (obtained with actual and model systems) and also on the radionuclide distribution throughout geochemical mobility forms suggest that the essential part of Cs, Pu, Eu, and Am migrates with fine-disperse suspended material, the transport and distribution of which is controlled by the hydrological regime of the Yenisey River. By contrast, strontium

Study of migration behavior of technogenic radionuclides in the Yenisey River-Kara Sea aquatic system

International Nuclear Information System (INIS)

Kuznetsov, Yu.; Legin, E.; Legin, V.; Shishlov, A.; Savitskii, Yu.; Novikov, A.; Goryachenkova, T.

2001-01-01

For 35 years Krasnoyarsk Mining-Chemical Combine (MCC) manufactures weapon plutonium in single-pass production reactors cooled with water of the Yenisey River. Water discharge from these reactors is the major source of radioactive contamination of the Yenisey River. We have demonstrated that after putting the reactors out of operation (in late 1992) the contamination level of the Yenisey River with short-lived radionuclides considerably decreased, and now the radioactive contamination is caused essentially by Cs-137, Eu-152, Pu-239,240, Sr-90, and Am-241, whose concentration in the aqueous phase is lower than in bottom sediments and, particularly, flood-land deposits by several orders of magnitude (except for Sr-90). The flood-land deposits are classified with the most contaminated environmental objects in the territories under the impact of MCC: their radioactivity is comparable with that of low-level waste. Taking into account the considerable depth and area of the flood-land deposits, this allows their classification as a great technogenic radiation anomaly. Comparison of the maximal Cs-137 and Pu-239,240 levels in flood-land soils and bottom sediments of the Yenisey River with those in bottom sediments of the Pripyat' River and the Kiev reservoir shows that these values are close each to other. A direct correlation is found between the spatial distribution of Cs-137 on the one hand and Pu-239,240, Eu-152, and Am-241 on the other hand in the aqueous phase and bottom sediments, which is not the case for Sr-90. Data on the distribution coefficients of the indicated radionuclides between the deposits and aqueous phase (obtained with actual and model systems) and also on the radionuclide distribution throughout geochemical mobility forms suggest that the essential part of Cs, Pu, Eu, and Am migrates with fine-disperse suspended material, the transport and distribution of which is controlled by the hydrological regime of the Yenisey River. By contrast, strontium

Technetium removal from aqueous wastes

International Nuclear Information System (INIS)

Fletcher, P.A.; Jones, C.P.; Junkison, A.R.; Turner, A.D.; Kavanagh, P.R.

1992-03-01

The research discussed in this report has compared several ''state of the art'' techniques for the removal of traces of the radionuclide, technetium, from aqueous wastes. The techniques investigated were: electrochemical reduction to an insoluble oxide, electrochemical ion exchange, seeded ultrafiltration and chemical reduction followed by filtration. Each technique was examined using a simulant based upon the waste generated by the Enhanced Actinide Removal Plant (EARP) at Sellafield. The technique selected for further investigation was direct electrochemical reduction which offers an ideal route for the removal of technetium from the stream (DFs 10-100) and can be operated continuously with a low power consumption 25 kW for the waste generated by EARP. Cell designs for scale up have been suggested to treat the 1000m 3 of waste produced every day. Future work is proposed to investigate the simultaneous removal of other key radionuclides, such as ruthenium, plutonium and cobalt as well as scale up of the resulting process and to investigate the effect of these other radionuclides on the efficiency of the electrochemical reduction technique for the removal of technetium. Total development and full scale plant costs are estimated to be of the order of 5 pounds - 10M, with a time scale of 5 -8 years to realisation. (author)

R7T7 glass alteration mechanism in an aqueous closed system: understanding and modelling the long term alteration kinetic

International Nuclear Information System (INIS)

Chave, T.

2007-10-01

The long term alteration rate of the French R7T7 nuclear glass has been investigated since many years because it will define the overall resistance of the radionuclide containment matrix. Recent studies have shown that the final rate remains constant or is slightly decreasing with time. It never reaches zero. Though this residual rate is very low, only 5 nm per year at 50 C, it would be the dominant alteration phenomenon in a geological repository. Two mechanisms are suggested for explaining such behaviour: diffusion in solution of elements from glass through an amorphous altered layer and precipitation of neo-formed phases. The diffusion processes are in agreement with a solid state diffusion mechanism and can lead to secondary phase precipitation due to solution concentration increases. Observed phases are mainly phyllosilicates and zeolites, in specific conditions. Phyllosilicates are expected to maintain the residual kinetic rate whereas alteration resumption could be observed in presence of zeolites at very high pH or temperature (10.5 at 90 C or temperature above 150 C). Both diffusion and neo-formed phase precipitation have been investigated in order to better understand their impact on the residual alteration rate and have then been modelled by a calculation code, coupling chemistry and transport, in order to be able to better anticipate the long term behaviour of the glass R7T7 in an aqueous closed system. (author)

Reducing the potential for migration of radioactive waste: Aqueous thermal degradation of the chelating agent disodium EDTA

International Nuclear Information System (INIS)

Boles, J.S.; Ritchie, K.; Crerar, D.A.

1987-01-01

Ethylenediaminetetraacetic acid (EDTA), a common component of cleaning solutions used for decontamination of radioactive equipment, has been associated with increased migration of radionuclides into local groundwaters at some radwaste disposal sites. It has been proposed that predisposal thermal degradation of EDTA-containing aqueous solutions may reduce the potential for chelate-enhanced mobilization of radionuclides at these sites. Aqueous thermal degradation experiments with disodium EDTA have shown that the compound degrades rapidly at 200 0 C with an activation energy of 114.3 +- 7.87 kJ/mol, and forms the decomposition product methyliminodiacetic acid (MIDA). A comparison of the values for stability constants of transition metal and actinide complexes with EDTA, MIDA, and two other reported degradation products, indicates that the chelating efficiency of the degradation products is 6 to 22 orders of magnitude lower than that of EDTA at 25 0 C. It is concluded that aqueous thermal degradation should significantly reduce the overall chelating efficiency of EDTA-containing solutions

Assessment of Radionuclides Release from Inshas LILW Disposal Facility Under Normal and Unusual Operational Conditions

International Nuclear Information System (INIS)

Zaki, A.A.

2008-01-01

Disposing of low and intermediate radioactive waste (LILW) is a big concern for Egypt due to the accumulated waste as a result of past fifty years of peaceful nuclear applications. Assessment of radionuclides release from Inshas LILW disposal facility under normal and unusual operational conditions is very important in order to apply for operation license of the facility. Aqueous release of radionuclides from this disposal facility is controlled by water flow, access of the water to the wasteform, release of the radionuclides from the wasteform, and transport to the disposal facility boundary. In this work, the release of 137 Cs , 6C o, and 90 Sr radionuclides from the Inshas disposal facility was studied under the change of operational conditions. The release of these radio contaminants from the source term to the unsaturated and saturated zones , to groundwater were studied. It was found that the concentration of radionuclides in a groundwater well located 150 m away from the Inshas disposal facility is less than the maximum permissible concentration in groundwater in both cases

Sediment and radionuclide transport in rivers: radionuclide transport modeling for Cattaraugus and Buttermilk Creeks, New York

International Nuclear Information System (INIS)

Onishi, Y.; Yabusaki, S.B.; Kincaid, C.T.; Skaggs, R.L.; Walters, W.H.

1982-12-01

SERATRA, a transient, two-dimensional (laterally-averaged) computer model of sediment-contaminant transport in rivers, satisfactorily resolved the distribution of sediment and radionuclide concentrations in the Cattaraugus Creek stream system in New York. By modeling the physical processes of advection, diffusion, erosion, deposition, and bed armoring, SERATRA routed three sediment size fractions, including cohesive soils, to simulate three dynamic flow events. In conjunction with the sediment transport, SERATRA computed radionuclide levels in dissolved, suspended sediment, and bed sediment forms for four radionuclides ( 137 Cs, 90 Sr, 239 240 Pu, and 3 H). By accounting for time-dependent sediment-radionuclide interaction in the water column and bed, SERATA is a physically explicit model of radionuclide fate and migration. Sediment and radionuclide concentrations calculated by SERATA in the Cattaraugus Creek stream system are in reasonable agreement with measured values. SERATRA is in the field performance phase of an extensive testing program designed to establish the utility of the model as a site assessment tool. The model handles not only radionuclides but other contaminants such as pesticides, heavy metals and other toxic chemicals. Now that the model has been applied to four field sites, including the latest study of the Cattaraugus Creek stream system, it is recommended that a final model be validated through comparison of predicted results with field data from a carefully controlled tracer test at a field site. It is also recommended that a detailed laboratory flume be tested to study cohesive sediment transport, deposition, and erosion characteristics. The lack of current understanding of these characteristics is one of the weakest areas hindering the accurate assessment of the migration of radionuclides sorbed by fine sediments of silt and clay

Research into the behaviour and transport of radionuclides in waters. Methods of testing sorption properties of materials present in aquatic environment and evaluation of results. Part of a coordinated programme on radiological and environmental studies in the Danube river catchment area

International Nuclear Information System (INIS)

Mansfeld, A.

1981-12-01

The presented study gives some basic information about the behaviour of selected radionuclides ( 226 Ra, U, 51 Cr, 60 Co, 0 879.Sr, 131 I, and 137 Cs) in aqueous environment. It proves the great significance of bottom sediments in the investigation of radionuclide sorption and migration and for obtaining data for the predicition of their behaviour in aqueous environment

MEASUREMENT OF RADIONUCLIDES USING ION CHROMATOGRAPHY AND FLOW-CELL SCINTILLATION COUNTING WITH PULSE SHAPE DISCRIMINATION

International Nuclear Information System (INIS)

Fjeld, R. A.; DeVol, T.A.; Leyba, J.D.

2000-01-01

Radiological characterization and monitoring is an important component of environmental management activities throughout the Department of Energy complex. Gamma-ray spectroscopy is the technology most often used for the detection of radionuclides. However, radionuclides which cannot easily be detected by gamma-ray spectroscopy, such as pure beta emitters and transuranics, pose special problems because their quantification generally requires labor intensive radiochemical separations procedures that are time consuming and impractical for field applications. This project focused on a technology for measuring transuranics and pure beta emitters relatively quickly and has the potential of being field deployable. The technology combines ion exchange liquid chromatography and on-line alpha/beta pulse shape discriminating scintillation counting to produce simultaneous alpha and beta chromatograms. The basic instrumentation upon which the project was based was purchased in the early 1990's. In its original commercial form, the instrumentation was capable of separating select activation/fission products in ionic forms from relatively pure aqueous samples. We subsequently developed the capability of separating and detecting actinides (thorium, uranium, neptunium, plutonium, americium, and curium) in less than 30 minutes (Reboul, 1993) and realized that the potential time savings over traditional radiochemical methods for isolating some of these radionuclides was significant. However, at that time, the technique had only been used for radionuclide concentrations that were considerably above environmental levels and for aqueous samples of relatively high chemical purity. For the technique to be useful in environmental applications, development work was needed in lowering detection limits; to be useful in applications involving non-aqueous matrices such as soils and sludges or complex aqueous matrices such as those encountered in waste samples, development work was needed in

Radionuclide examinations

International Nuclear Information System (INIS)

Lentle, B.C.

1989-01-01

This paper reports on radionuclide examinations of the pancreas. The pancreas, situated retroperitonally high in the epigastrium, was a particularly difficult organ to image noninvasively before ultrasonography and computed tomography (CT) became available. Indeed the organ still remains difficult to examine in some patients, a fact reflected in the variety of methods available to evaluate pancreatic morphology. It is something of a paradox that the pancreas is metabolically active and physiologically important but that its examination by radionuclide methods has virtually ceased to have any role in day-to-day clinical practice. To some extent this is caused by the tendency of the pancreas's commonest gross diseases emdash carcinoma and pancreatitis, for example emdash to result in nonfunction of the entire organ. Disorders of pancreatic endocrine function have generally not required imaging methods for diagnosis, although an understanding of diabetes mellitus and its nosology has been advanced by radioimmunoassay of plasma insulin concentrations

Research on advanced aqueous reprocessing of spent nuclear fuel: literature study

Energy Technology Data Exchange (ETDEWEB)

Van Hecke, K.; Goethals, P.

2006-07-15

The goal of the partitioning and transmutation strategy is to reduce the radiotoxicity of spent nuclear fuel to the level of natural uranium in a short period of time (about 1000 years) and thus the required containment period of radioactive material in a repository. Furthermore, it aims to reduce the volume of waste requiring deep geological disposal and hence the associated space requirements and costs. Several aqueous as well as pyrochemical separation processes have been developed for the partitioning of the long-lived radionuclides from the remaining of the spent fuel. This report aims to describe and compare advanced aqueous reprocessing methods.

Research on advanced aqueous reprocessing of spent nuclear fuel: literature study

International Nuclear Information System (INIS)

Van Hecke, K.; Goethals, P.

2006-01-01

The goal of the partitioning and transmutation strategy is to reduce the radiotoxicity of spent nuclear fuel to the level of natural uranium in a short period of time (about 1000 years) and thus the required containment period of radioactive material in a repository. Furthermore, it aims to reduce the volume of waste requiring deep geological disposal and hence the associated space requirements and costs. Several aqueous as well as pyrochemical separation processes have been developed for the partitioning of the long-lived radionuclides from the remaining of the spent fuel. This report aims to describe and compare advanced aqueous reprocessing methods.

Transcuticular translocation of radionuclides on plant leaf surfaces

Energy Technology Data Exchange (ETDEWEB)

Matsumoto, Ken-ichi; Watanabe, Tadakazu; Ambe, Shizuko; Yamaguchi, Isamu [Institute of Physical and Chemical Research, Wako, Saitama (Japan)

1996-12-31

The cuticle covering all the outermost surfaces of the aerial parts of plants could play a selective role in uptake and translocation of radionuclides from air into plants. In this study, we investigated the transcuticular uptake and translocation behavior via water droplets of various radionuclides in red clover, orchard grass, Japanese radish and mung bean. Ten {mu}l of an aqueous solution of the multitracer generated from Au was applied to the upper surface of the 2nd leaf of the plants at the 5th leaf stage. The plants were then grown for 14 days at 25degC and 70% RH under illumination of artificial solar lights. The transcuticular uptake and translocation throughout the plant were periodically assayed by determining the radioactivity in the surface residue, the cuticle layer beneath the applied site, the leaf area outside the applied site, the other aerial parts and the root of the plant, using an HPGe detector. The applied radionuclides were absorbed into, in turn, the cuticle layer beneath the applied site and then translocated through the cuticle to the inner tissue and eventually to the other aerial parts and finally to the roots, of the plant. The distribution and accumulation in the plant seems to depend upon the characteristics of each radionuclide and plant species. Ca{sup *} and Te{sup *} tended to remain on leaf surfaces without being absorbed into the cuticle. On the other hand, Sc{sup *}, Co{sup *}, Zn{sup *}, Se{sup *}, Rb{sup *}, and Eu{sup *} were easily absorbed and translocated to every part of the plant including the root. The other radionuclides such as Be{sup *}, Mn{sup *}, Sr{sup *}, Y{sup *}, Ba{sup *}, Ce{sup *}, Pm{sup *}, Gd{sup *}, Hf{sup *}, Yb{sup *}, Lu{sup *}, Os{sup *}, Ir{sup *}, and Pt{sup *} remained in the region close to the site of their application. The above results possibly indicate the existence of mechanisms common to these plants for selective transcuticular uptake and translocation of radionuclides within plant

Transcuticular translocation of radionuclides on plant leaf surfaces

International Nuclear Information System (INIS)

Matsumoto, Ken-ichi; Watanabe, Tadakazu; Ambe, Shizuko; Yamaguchi, Isamu

1996-01-01

The cuticle covering all the outermost surfaces of the aerial parts of plants could play a selective role in uptake and translocation of radionuclides from air into plants. In this study, we investigated the transcuticular uptake and translocation behavior via water droplets of various radionuclides in red clover, orchard grass, Japanese radish and mung bean. Ten μl of an aqueous solution of the multitracer generated from Au was applied to the upper surface of the 2nd leaf of the plants at the 5th leaf stage. The plants were then grown for 14 days at 25degC and 70% RH under illumination of artificial solar lights. The transcuticular uptake and translocation throughout the plant were periodically assayed by determining the radioactivity in the surface residue, the cuticle layer beneath the applied site, the leaf area outside the applied site, the other aerial parts and the root of the plant, using an HPGe detector. The applied radionuclides were absorbed into, in turn, the cuticle layer beneath the applied site and then translocated through the cuticle to the inner tissue and eventually to the other aerial parts and finally to the roots, of the plant. The distribution and accumulation in the plant seems to depend upon the characteristics of each radionuclide and plant species. Ca * and Te * tended to remain on leaf surfaces without being absorbed into the cuticle. On the other hand, Sc * , Co * , Zn * , Se * , Rb * , and Eu * were easily absorbed and translocated to every part of the plant including the root. The other radionuclides such as Be * , Mn * , Sr * , Y * , Ba * , Ce * , Pm * , Gd * , Hf * , Yb * , Lu * , Os * , Ir * , and Pt * remained in the region close to the site of their application. The above results possibly indicate the existence of mechanisms common to these plants for selective transcuticular uptake and translocation of radionuclides within plant tissues, though their translocation was considerably influenced by the plant species. (author)

ITE CHARACTERIZATION TO SUPPORT CONCEPTUAL MODEL DEVELOPMENT FOR SUBSURFACE RADIONUCLIDE TRANSPORT

Science.gov (United States)

Remediation of radionuclide contaminants in ground water often begins with the development of conceptual and analytical models that guide our understanding of the processes controlling radionuclide transport. The reliability of these models is often predicated on the collection o...

Radionuclide toxicity

International Nuclear Information System (INIS)

Galle, P.

1982-01-01

The aim of this symposium was to review the radionuclide toxicity problems. Five topics were discussed: (1) natural and artificial radionuclides (origin, presence or emission in the environment, human irradiation); (2) environmental behaviour of radionuclides and transfer to man; (3) metabolism and toxicity of radionuclides (radioiodine, strontium, rare gas released from nuclear power plants, ruthenium-activation metals, rare earths, tritium, carbon 14, plutonium, americium, curium and einsteinium, neptunium, californium, uranium) cancerogenous effects of radon 222 and of its danghter products; (4) comparison of the hazards of various types of energy; (5) human epidemiology of radionuclide toxicity (bone cancer induction by radium, lung cancer induction by radon daughter products, liver cancer and leukaemia following the use of Thorotrast, thyroid cancer; other site of cancer induction by radionuclides) [fr

Radionuclide migration in crystalline rock fractures

International Nuclear Information System (INIS)

Hoelttae, P.

2002-01-01

Crystalline rock has been considered as a host medium for the repository of high radioactive spent nuclear fuel in Finland. The geosphere will act as an ultimate barrier retarding the migration of radionuclides to the biosphere if they are released through the technical barriers. Radionuclide transport is assumed to take place along watercarrying fractures, and retardation will occur both in the fracture and within the rock matrix. To be able to predict the transport and retardation of radionuclides in rock fractures and rock matrices, it is essential to understand the different phenomena involved. Matrix diffusion has been indicated to be an important mechanism, which will retard the transport of radionuclides in rock fractures. Both dispersion and matrix diffusion are processes, which can have similar influences on solute breakthrough curves in fractured crystalline rock. In this work, the migration of radionuclides in crystalline rock fractures was studied by means of laboratory scale column methods. The purpose of the research was to gain a better understanding of various phenomena - particularly matrix diffusion - affecting the transport and retardation behaviour of radionuclides in fracture flow. Interaction between radionuclides and the rock matrix was measured in order to test the compatibility of experimental retardation parameters and transport models used in assessing the safety of underground repositories for spent nuclear fuel. Rock samples of mica gneiss and of unaltered, moderately altered and strongly altered tonalite represented different rock features and porosities offering the possibility to determine experimental boundary limit values for parameters describing both the transport and retardation of radionuclides and rock matrix properties. The dominant matrix diffusion behaviour was demonstrated in porous ceramic column and gas diffusion experiments. Demonstration of the effects of matrix diffusion in crystalline rock fracture succeeded for the

Transuranic radionuclides dispersed into the aquatic environment, a bibliography

Energy Technology Data Exchange (ETDEWEB)

Noshkin, V.E.; Stoker, A.C.; Wong, Kai M. [and others

1994-04-01

The purpose of this project was to compile a bibliography of references containing environmental transuranic radionuclide data. Our intent was to identify those parameters affecting transuranic radionuclide transport that may be generic and those that may be dependent on chemical form and/or environmental conditions (i.e., site specific) in terrestrial, aquatic and atmospheric environments An understanding of the unique characteristics and similarities between source terms and environmental conditions relative to transuranic radionuclide transport and cycling will provide the ability to assess and predict the long term impact on man and the environment. An additional goal of our literature review, was to extract the ranges of environmental transuranic radionuclide data from the identified references for inclusion in a data base. Related to source term, these ranges of data can be used to calculate the dose to man from the radionuclides, and to perform uncertainty analyses on these dose assessments. On the basis of our reviews, we have arbitrarily outlined five general source terms. These are fallout, fuel cycle waste, accidents, disposal sites and resuspension. Resuspension of the transuranic radionuclides is a unique source term, in that the radionuclides can originate from any of the other source terms. If these transuranic radionuclides become resuspended into the air, they then become important as a source of inhaled radionuclides.

Statistical analysis of fallout radionuclides transfer to paddy-field rice

International Nuclear Information System (INIS)

Takahashi, T.; Morisawa, S.; Inoue, Y.

1996-01-01

Radionuclides released from nuclear facilities to atmosphere are transported through various pathways in biosphere and cause human exposure. Among these radionuclides transfer pathways, an ingestion of crops containing radionuclides is one of the dominant pathway for human exposure. For the safety assessment of nuclear facilities, it is important to understand the behavior of radionuclides in agricultural environment and to describe them in a mathematical model. In this paper, a statistical model is proposed for estimating the concentration of fallout radionuclides in paddy-field rice, the staple food for Japanese people. For describing behavior of fallout radionuclides in a paddy-field, a dynamic model and a statistical model have been proposed respectively. The model used in this study has been developed assuming that the amount of radionuclides transfer to brown rice (hulled rice) or polished rice through direct deposition of airborne radionuclides (the direct deposition pathway) and root uptake from a paddy soil (the root uptake pathway) are proportional to the deposition flux of radionuclides and concentration of radionuclides in paddy soil respectively. That is, the model has two independent variables; the deposition flux of radionuclides and the concentration of radionuclides in the paddy soil, and has single dependent variable; the concentration of radionuclides in brown rice or polished rice. The regression analysis is applied by using environmental monitoring data. Then the distribution of radionuclides between rice-bran (skin part of rice crop) and polished rice (core part) through both the direct deposition pathway and the root uptake pathway are evaluated by the model. (author)

Methods of separating short half-life radionuclides from a mixture of radionuclides

International Nuclear Information System (INIS)

Bray, L.A.; Ryan, J.L.

1998-01-01

The present invention is a method of obtaining a radionuclide product selected from the group consisting of 223 Ra and 225 Ac, from a radionuclide ''cow'' of 227 Ac or 229 Th respectively. The method comprises the steps of (a) permitting ingrowth of at least one radionuclide daughter from said radionuclide ''cow'' forming an ingrown mixture; (b) insuring that the ingrown mixture is a nitric acid ingrown mixture; (c) passing the nitric acid ingrown mixture through a first nitrate form ion exchange column which permits separating the ''cow'' from at least one radionuclide daughter; (d) insuring that the at least one radionuclide daughter contains the radionuclide product; (e) passing the at least one radionuclide daughter through a second ion exchange column and separating the at least one radionuclide daughter from the radionuclide product and (f) recycling the at least one radionuclide daughter by adding it to the ''cow''. In one embodiment the radionuclide ''cow'' is the 227 Ac, the at least one daughter radionuclide is a 227 Th and the product radionuclide is the 223 Ra and the first nitrate form ion exchange column passes the 227 Ac and retains the 227 Th. In another embodiment the radionuclide ''cow'' is the 229 Th, the at least one daughter radionuclide is a 225 Ra and said product radionuclide is the 225 Ac and the 225 Ac and nitrate form ion exchange column retains the 229 Th and passes the 225 Ra/Ac. 8 figs

Progress in determination of long-lived radionuclides by inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Becker, J.S.; Dietze, H.J.

2000-01-01

Mass spectrometric methods (such as inductively coupled plasma mass spectrometry - ICP-MS and laser ablation (LA)-ICP-MS) with their ability to provide a very sensitive multielemental and precise isotopic analysis have become established for the determination of radionuclides in quite different sample materials. The determination of long-lived radionuclides is of increasing interest for the characterization of radioactive waste materials and for the detection of radionuclide contamination in environmental materials in which several radioactive nuclides are present from fallout due to nuclear weapons testing, nuclear power plants or nuclear accidents. Due to its multielement capability, excellent sensitivity, low detection limits (up to sub pg I 1 range), very good precision, easy sample preparation and measurement procedures ICP-MS of aqueous solutions has been increasingly applied for the ultrasensitive determination of long-lived radionuclides such as 99 Tc, 129 I, 230 Th, 232 Th, 234 U, 235 U, 236 U, 239 Pu, 240 Pu and 241 Am and precise isotope ratio measurements of U,Th and Pu. The application especially of microanalytical methods (analysis of some MU by flow injection and on-line coupling techniques as capillary electrophoresis (CE-ICP-MS) or HPLC-ICP-MS) for the precise determination nuclide abundances and concentration of long-lived radionuclides at ultra trace concentration levels in radioactive waste and also for controlling contamination from radioactive waste in the environment is a challenging task

Methods of separating short half-life radionuclides from a mixture of radionuclides

Science.gov (United States)

Bray, Lane A.; Ryan, Jack L.

1998-01-01

The present invention is a method of obtaining a radionuclide product selected from the group consisting of .sup.223 Ra and .sup.225 Ac, from a radionuclide "cow" of .sup.227 Ac or .sup.229 Th respectively. The method comprises the steps of a) permitting ingrowth of at least one radionuclide daughter from said radionuclide "cow" forming an ingrown mixture; b) insuring that the ingrown mixture is a nitric acid ingrown mixture; c) passing the nitric acid ingrown mixture through a first nitrate form ion exchange column which permits separating the "cow" from at least one radionuclide daughter; d) insuring that the at least one radionuclide daughter contains the radionuclide product; e) passing the at least one radionuclide daughter through a second ion exchange column and separating the at least one radionuclide daughter from the radionuclide product and f) recycling the at least one radionuclide daughter by adding it to the "cow". In one embodiment the radionuclide "cow" is the .sup.227 Ac, the at least one daughter radionuclide is a .sup.227 Th and the product radionuclide is the .sup.223 Ra and the first nitrate form ion exchange column passes the .sup.227 Ac and retains the .sup.227 Th. In another embodiment the radionuclide "cow"is the .sup.229 Th, the at least one daughter radionuclide is a .sup.225 Ra and said product radionuclide is the .sup.225 Ac and the .sup.225 Ac and nitrate form ion exchange column retains the .sup.229 Th and passes the .sup.225 Ra/Ac.

Colloid-facilitated radionuclide transport: a regulatory perspective

Science.gov (United States)

Dam, W. L.; Pickett, D. A.; Codell, R. B.; Nicholson, T. J.

2001-12-01

What hydrogeologic-geochemical-microbial conditions and processes affect migration of radionuclides sorbed onto microparticles or native colloid-sized radionuclide particles? The U.S. Nuclear Regulatory Commission (NRC) is responsible for protecting public health, safety, and the environment at numerous nuclear facilities including a potential high-level nuclear waste disposal site. To fulfill these obligations, NRC needs to understand the mechanisms controlling radionuclide release and transport and their importance to performance. The current focus of NRC staff reviews and technical interactions dealing with colloid-facilitated transport relates to the potential nuclear-waste repository at Yucca Mountain, Nevada. NRC staff performed bounding calculations to quantify radionuclide releases available for ground-water transport to potential receptors from a Yucca Mountain repository. Preliminary analyses suggest insignificant doses of plutonium and americium colloids could be derived from spent nuclear fuel. Using surface complexation models, NRC staff found that colloids can potentially lower actinide retardation factors by up to several orders of magnitude. Performance assessment calculations, in which colloidal transport of plutonium and americium was simulated by assuming no sorption or matrix diffusion, indicated no effect of colloids on human dose within the 10,000 year compliance period due largely to long waste-package lifetimes. NRC staff have identified information gaps and developed technical agreements with the U.S. Department of Energy (DOE) to ensure sufficient information will be presented in any potential future Yucca Mountain license application. DOE has agreed to identify which radionuclides could be transported via colloids, incorporate uncertainties in colloid formation, release and transport parameters, and conceptual models, and address the applicability of field data using synthetic microspheres as colloid analogs. NRC is currently

LA-ICP-MS for Trace Analysis of Long-Lived Radionuclides in Solid Non-conducting Radioactive Waste Samples

International Nuclear Information System (INIS)

Becker, J.S.; Gastel, M.; Tenzler, D.; Dietze, H.J.

1999-01-01

The characterization of radioactive waste materials from nuclear reactors for recycling and final storage requires fast, sensitive and precise analytical methods, which are able to determine long-lived radionuclidic ultra traces in a short time. For the determination of long-lived α and β ray-emitting nuclides besides the classical radiochemical methods which are mostly include time-consuming radiochemical separation procedures, to an increasing extent inductively coupled plasma mass spectrometry (ICP-MS) has been used successfully as a powerful trace, ultra trace and isotopic analytical method for the determination of long-lived radionuclides in aqueous solutions [1-3

Towards improved understanding of radionuclide transfer in forests and preparedness to handle contaminated forests. Proceedings

International Nuclear Information System (INIS)

Vetikko, V.; Rantavaara, A.; Aro, L.; Plamboeck, A.H.; Straelberg, E.

2009-06-01

The seminar was planned and arranged by four Nordic organisations and provided a forum for exchange of information for Nordic scientists currently working in the field of forest radioecology or using the data. Presentations of research on nutrient cycling and radionuclide distribution in boreal forests, discussion on the needs for future research and attendance of experts on forestry, forest research and radioecology offered a unique opportunity to disseminate and receive information. The seminar programme was composed of topics of radioecology and forest research, assessment of radionuclide contamination and management of contaminated forests. Also sampling in forests, monitoring and modelling of environmental impact of disposal of spent nuclear fuel, and recent radioecological studies on forests were handled. Future research was emphasised in discussions. Below is a short compilation of these discussions: - Comprehensive planning of research projects contributing to a programme with long-term aims is possible in broadly-based multidisciplinary collaboration. Thereby independent initiatives and less coherent plans can be replaced. - Clear definition of hypotheses, planning and improving the specific methods for sampling and laboratory analyses were found crucial. - Effects of intensive biofuel harvesting on the nutrient and radionuclide flows in forests are major issues in the next decades. - Gaps in knowledge, such as lack of data on processes contributing to radionuclide distributions in forests, and on certain long-lived radionuclides (those of Cl, Tc, Np, etc.) contributing to the environmental impact of final disposal of spent nuclear fuel. Topical seminars like the one accomplished are welcome in the future; compiling acute issues of multidisciplinary nature for focussed expert review and discussion can be very rewarding in many ways. To support communication and future collaboration, an informal forest network was launched in the seminar. Information is

Towards improved understanding of radionuclide transfer in forests and preparedness to handle contaminated forests. Proceedings

Energy Technology Data Exchange (ETDEWEB)

Vetikko, V.; Rantavaara, A. (Radiation and Nuclear Safety Authority (STUK) (Finland)); Aro, L. (Finnish Forest Research Institute (METLA) (Finland)); Plamboeck, A.H. (The Swedish Defence Research Agency (FOI) (Sweden)); Straalberg, E. (Institute for Energy Technology (IFE) (Norway))

2009-06-15

The seminar was planned and arranged by four Nordic organisations and provided a forum for exchange of information for Nordic scientists currently working in the field of forest radioecology or using the data. Presentations of research on nutrient cycling and radionuclide distribution in boreal forests, discussion on the needs for future research and attendance of experts on forestry, forest research and radioecology offered a unique opportunity to disseminate and receive information. The seminar programme was composed of topics of radioecology and forest research, assessment of radionuclide contamination and management of contaminated forests. Also sampling in forests, monitoring and modelling of environmental impact of disposal of spent nuclear fuel, and recent radioecological studies on forests were handled. Future research was emphasised in discussions. Below is a short compilation of these discussions: - Comprehensive planning of research projects contributing to a programme with long-term aims is possible in broadly-based multidisciplinary collaboration. Thereby independent initiatives and less coherent plans can be replaced. - Clear definition of hypotheses, planning and improving the specific methods for sampling and laboratory analyses were found crucial. - Effects of intensive biofuel harvesting on the nutrient and radionuclide flows in forests are major issues in the next decades. - Gaps in knowledge, such as lack of data on processes contributing to radionuclide distributions in forests, and on certain long-lived radionuclides (those of Cl, Tc, Np, etc.) contributing to the environmental impact of final disposal of spent nuclear fuel. Topical seminars like the one accomplished are welcome in the future; compiling acute issues of multidisciplinary nature for focussed expert review and discussion can be very rewarding in many ways. To support communication and future collaboration, an informal forest network was launched in the seminar. Information is

Factors influencing the transfer of radionuclides in agricultural food chains

International Nuclear Information System (INIS)

Vandecasteele, C.M.; Zeevaert, Th.; Kirchmann, R.

1991-01-01

The applications of nuclear energy have led and will continue to lead to routine or accidental discharges of radioactive elements into the atmospheric and/or aquatic environment resulting in the exposure of populations to ionising radiations. The radionuclides released into the atmosphere are transported downwind, dispersed by the atmospheric mixing phenomena and progressively settled by deposition processes. During the passage of the radioactive cloud, people are irradiated externally as well as internally by inhalation. After the passage of the cloud, exposure of the population continues via three main pathways: external irradiation from the radionuclides deposited on the ground, inhalation of resuspended contaminated particles and ingestion of contaminated food products. When discharged into aquatic systems, the radionuclides can be partly removed from the aqueous phase by adsorption on suspended solids and bottom sediments. As the radioactivity disperses, there is a continuing exchange between water and solid phases. The contaminated sediments deposited on the banks of rivers, lakes and coastal area lead to external irradiation of people spending time at these sites. The residual activity in water exposes man internally through the ingestion of drinking water and food products, contaminated by irrigation of vegetation and ingestion of water by livestock. Among the various exposure pathways, the main route of entry of fission products and most other artificial radionuclides into man has been identified as uptake from the diet. Since agricultural products constitute the basic diet of most populations, the fate and behavior of radionuclides in agricultural ecosystems are of primary importance when assessing the exposure risk of man from environmental releases of radioactivity. 69 refs., 4 figs

Underground radionuclide migration at the Nevada Test Site

International Nuclear Information System (INIS)

Nimz, G.J.; Thompson, J.L.

1992-01-01

This document reviews results from a number of studies concerning underground migration of radionuclides from nuclear test cavities at the Nevada Test Site (NTS). Discussed are all cases known to the Department of Energy's Hydrology and Radionuclide Migration Program where radionuclides have been detected outside of the immediate vicinity of nuclear test cavities that are identifiable as the-source of the nuclides, as well as cases where radionuclides might have been expected and were intentionally sought but not fixed. There are nine locations where source-identifiable radionuclide migration has been detected, one where migration was purposely induced by pumping, and three where migration might be expected but was not found. In five of the nine cases of non-induced migration, the inferred migration mechanism is prompt fracture injection during detonation. In the other four cases, the inferred migration mechanism is water movement. In only a few of the reviewed cases can the actual migration mechanism be stated with confidence, and the attempt has been made to indicate the level of confidence for each case. References are cited where more information may be obtained. As an aid to future study, this document concludes with a brief discussion of the aspects of radionuclide migration that, as the present review indicates, are not yet understood. A course of action is suggested that would produce a better understanding of the phenomenon of radionuclide migration

Understanding and controlling the step bunching instability in aqueous silicon etching

Science.gov (United States)

Bao, Hailing

Chemical etching of silicon has been widely used for more than half a century in the semiconductor industry. It not only forms the basis for current wafer cleaning processes, it also serves as a powerful tool to create a variety of surface morphologies for different applications. Its potential for controlling surface morphology at the atomic scale over micron-size regions is especially appealing. In spite of its wide usage, the chemistry of silicon etching is poorly understood. Many seemingly simple but fundamental questions have not been answered. As a result, the development of new etchants and new etching protocols are based on expensive and tedious trial-and-error experiments. A better understanding of the etching mechanism would direct the rational formulation of new etchants that produce controlled etch morphologies. Particularly, micron-scale step bunches spontaneously develop on the vicinal Si(111) surface etched in KOH or other anisotropic aqueous etchants. The ability to control the size, orientation, density and regularity of these surface features would greatly improve the performance of microelectromechanical devices. This study is directed towards understanding the chemistry and step bunching instability in aqueous anisotropic etching of silicon through a combination of experimental techniques and theoretical simulations. To reveal the cause of step-bunching instability, kinetic Monte Carlo simulations were constructed based on an atomistic model of the silicon lattice and a modified kinematic wave theory. The simulations showed that inhomogeneity was the origin of step-bunching, which was confirmed through STM studies of etch morphologies created under controlled flow conditions. To quantify the size of the inhomogeneities in different etchants and to clarify their effects, a five-parallel-trench pattern was fabricated. This pattern used a nitride mask to protect most regions of the wafer; five evenly spaced etch windows were opened to the Si(110

Radionuclide trap

International Nuclear Information System (INIS)

McGuire, J.C.

1978-01-01

The deposition of radionuclides manganese-54, cobalt-58 and cobalt-60 from liquid sodium coolant is controlled by providing surfaces of nickel or high nickel alloys to extract the radionuclides from the liquid sodium, and by providing surfaces of tungsten, molybdenum or tantalum to prevent or retard radionuclide deposition

Natural and Synthetic Barriers to Immobilize Radionuclides

International Nuclear Information System (INIS)

Um, W.

2011-01-01

solution conditions. Particularly for temperature extremes, the backfill material should be able to withstand elevated temperatures resulting from the heat generating high-radiation fluxes of solidified high-level nuclear wastes. The barrier materials are most commonly synthetic or natural inorganic materials that selectively adsorb radionuclide and metallic contaminants. In here, both natural and synthetic barrier materials are discussed to increase our understanding of potential retardation of radionuclide transport in the repository

Experimental analysis of plastic materials containing radionuclides for decontamination viability

International Nuclear Information System (INIS)

Tazaki, Kazue; Nakano, Mikio; Takehara, Teruaki; Ishigaki, Yasuhito; Nakagawa, Hideaki

2015-01-01

After the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident on 11 March, 2011, the high radioactive dosage was found in polluted water for agriculture use at Baba, Haramachi, Minami-Soma, Fukushima Prefecture, Japan. Field experiment for decontamination of water had been studied by using commercial plastic materials. The agricultural water comes from Tetsuzan dam is full of radioactive-contaminated water. Experimental analysis showed that the plastic materials can take up radioactive elements for several months soaked in the polluted agricultural water. The quantitative analyses using X-ray fluorescence analysis, Ge semiconductor and scanning electron microscopy equipped with energy dispersive X-ray spectrometer (SEM-EDS), revealed the detection of the radionuclides on the plastic materials with diatom and clays. The results suggest the adsorption of radionuclides on the surface of plastic materials due to FDNPP accident. The plastic materials associated with clays and diatoms could be stronger carriers of radionuclides in the polluted water. Adherence of diatoms to the plastic fiber in the water for 7 months suggested that some plastic materials were taking up heavy metals (Zn, Ba, Pb, Sb) with radioactive elements (Cs etc.). Mechanisms by which radioactive pollutants and microorganisms are adsorbed onto and desorbed from clays at aqueous interface can be understood by combining chemical analysis with electron microscopy observation. (author)

Potential for radionuclide immobilization in the EBS/NFE: solubility limiting phases for neptunium, plutonium, and uranium

Energy Technology Data Exchange (ETDEWEB)

Rard, J. A., LLNL

1997-10-01

Retardation and dispersion in the far field of radionuclides released from the engineered barrier system/near field environment (EBS/NFE) may not be sufficient to prevent regulatory limits being exceeded at the accessible environment. Hence, a greater emphasis must be placed on retardation and/or immobilization of radionuclides in the EBS/NFE. The present document represents a survey of radionuclide-bearing solid phases that could potentially form in the EBS/NFE and immobilize radionuclides released from the waste package and significantly reduce the source term. A detailed literature search was undertaken for experimental solubilities of the oxides, hydroxides, and various salts of neptunium, plutonium, and uranium in aqueous solutions as functions of pH, temperature, and the concentrations of added electrolytes. Numerous solubility studies and reviews were identified and copies of most of the articles were acquired. However, this project was only two months in duration, and copies of some the identified solubility studies could not be obtained at short notice. The results of this survey are intended to be used to assess whether a more detailed study of identified low- solubility phase(s) is warranted, and not as a data base suitable for predicting radionuclide solubility. The results of this survey may also prove useful in a preliminary evaluation of the efficacy of incorporating chemical additives to the EBS/NFE that will enhance radionuclide immobilization.

Radionuclide cisternography

International Nuclear Information System (INIS)

Song, H.H.

1980-01-01

The purpose of this thesis is to show that radionuclide cisternography makes an essential contribution to the investigation of cerebrospinal fluid (CSF) dynamics, especially for the investigation of hydrocephalus. The technical details of radionuclide cisternography are discussed, followed by a description of the normal and abnormal radionuclide cisternograms. The dynamics of CFS by means of radionuclide cisternography were examined in 188 patients in whom some kind of hydrocephalus was suspected. This study included findings of anomalies associated with hydrocephalus in a number of cases, such as nasal liquorrhea, hygromas, leptomeningeal or porencephalic cysts. The investigation substantiates the value of radionuclide cisternography in the diagnosis of disturbances of CSF flow. The retrograde flow of radiopharmaceutical into the ventricular system (ventricular reflux) is an abnormal phenomenon indicating the presence of communicating hydrocephalus. (Auth.)

Radionuclides retention in C-S-H, main phases of cement matrices for low and intermediate-level wastes

International Nuclear Information System (INIS)

Badillo A, V. E.; Lopez R, C.; Vidal M, J.; Gutierrez B, O.

2014-10-01

Knowing that the behavior of cementitious materials based on hydraulic binder called cement is essentially determined by the physicochemical evolution of the cement paste (water + cement) which constitutes it, the evolution of the cement paste in contact with different aqueous solutions is studied since one of the main risks in safety of systems is composed of surface and groundwater, which contribute to the alteration of the different barriers and represent the main way of radionuclides transport. The calcium silicates CSH are the main phases that compose the systems based on Portland cement. The hydrates calcium silicates possess a high degree of structural complexity which includes crystalline, partially crystalline and amorphous phases. In this study the microstructures of the CSH phases as well as the retention of radionuclide Sr (II) are studied through the 87m Sr in formulations of water/cement w/c = 0.55; experimental values of K d low around 20 ml g -1 are obtained in function of hydration time of the cement paste in equilibrium with aqueous solutions. (Author)

Uptake of cesium and cobalt radionuclides from simulated radioactive wastewater by Ludwigia stolonifera aquatic plant

Energy Technology Data Exchange (ETDEWEB)

Saleh, H.M., E-mail: hosamsaleh70@yahoo.com [Radioisotope Department, Nuclear Research Center, Atomic Energy Authority, Dokki 12311, Giza (Egypt); Bayoumi, T.A. [Radioisotope Department, Nuclear Research Center, Atomic Energy Authority, Dokki 12311, Giza (Egypt); Mahmoud, H.H. [Radioisotope Department, Nuclear Research Center, Atomic Energy Authority, Dokki 12311, Giza (Egypt); Central Laboratory for Elemental and Isotopic Analysis, Nuclear Research Center, Atomic Energy Authority (Egypt); Aglan, R.F. [Department of Analytical Chemistry, Hot Laboratories Center, Atomic Energy Authority, 13759 (Egypt)

2017-04-15

Highlights: • Radioactive contamination is a serious environmental problem. • Phytoremediation is a proper technique for soil and water decontamination. • Aquatic plant, Ludwigia stolonifera, for bioaccumulation of radionuclides. • Factors affecting uptake efficiency of {sup 137}Cs and {sup 60}Co radionuclides. - Abstract: The article reported herein was conducted as part of comprehensive study considered to evaluate the efficiency of Ludwigia stolonifera as a local aquatic plant located in the Egyptian environment for phytoremediation of hazardous toxic and radioactive elements dissolved in aqueous wastes dispersed from industrial and urban applications through the human activities. Ludwigia stolonifera was immersed in single and binary solution of {sup 60}Co and {sup 137}Cs. The specific uptake rate of plant was determined at various activity contents of radionuclides, multiplied masses of plant, lighting exposure and different pH values. Accumulation of {sup 60}Co and {sup 137}Cs in mixture was more than 95% and 65% respectively. pH was less effective than the other evaluated parameters.

Natural decay series radionuclide studies at the Needle's Eye Natural Analogue Site, II, 1989-1991

International Nuclear Information System (INIS)

MacKenzie, A.B.; Whitton, A.M.; Shimmield, T.M.; Jemielita, R.A.; Scott, R.D.; Hooker, P.J.

1991-12-01

HMIP has a research programme investigating some naturally radioactive sites as geochemical analogues of radionuclide migration. The objective is to test thermodynamic databases and computer codes used for modelling radionuclide migration under environmental conditions. This report describes the study of transport and retardation processes affecting natural radionuclides, mainly uranium (U), in the vicinity of pitchblende veins in the cliff at Needle's Eye on the Solway Coast, SW Scotland. The natural decay series results from this study have been used to develop a well constrained geochemical model within which the codes can be tested. A conceptual geochemical model for the behaviour of U at the site was developed in stage I of the study; work in stage II is concerned with improving the information available on the U source term, groundwater chemistry, U aqueous phase specification, U retardation by fracture-lining minerals during fissure flow of groundwater, U-organic associations and loss of U from the site by stream drainage. (author)

Sorption of short-lived radionuclides in a layer of sorbent with spherical granules

International Nuclear Information System (INIS)

Karlin, Yu.V.

1993-01-01

Sorption methods have found wide application in the purification of liquid radioactive wastes. The working element in sorption methods for this purpose is usually a sorption column with a fixed layer of sorbent. Continuous-action equipment with a moving layer of sorbent is very seldom used. When a fixed layer of sorbent is used its wear and prolonged mixing in the sorption column are reduced to a minimum, and maximum purification is achieved due to the advantages of the dynamic method of sorption over the static method. The time of protective action of the sorbent layer is determined by the time taken for the radionuclide to pass through the sorption column, and for the majority of radionuclides is determined by numerous parameters, including the type of sorbent and radionuclide, the rate of flow through the sorbent, the size of the sorbent granules, etc. The physical and chemical aspects of this process have been investigated in detail, and numerous methods for modeling it mathematically have been developed and have been used to develop methods of designing sorption column apparatus. The specific nature of the radionuclides as unstable materials enables the hypothetical case of a open-quotes perpetualclose quotes sorption filter to be represented. In fact, to achieve this it is only necessary to assume that the half-life of the radionuclide is so small that the rate of decay of the radionuclide in the sorption column (both in the sorbed state and in the aqueous phase of the sorption layer) is equal to the rate that it is fed into the column in the flow of liquid radioactive waste. In this case the sorption front of the radionuclide in the column wall remains fixed after a certain initial period. In this paper, a mathematical model of such a hypothetical filter for the case of spherical sorbent granules is considered

An overview of BORIS: Bioavailability of Radionuclides in Soils

International Nuclear Information System (INIS)

Tamponnet, C.; Martin-Garin, A.; Gonze, M.-A.; Parekh, N.; Vallejo, R.; Sauras-Yera, T.; Casadesus, J.; Plassard, C.; Staunton, S.; Norden, M.; Avila, R.; Shaw, G.

2008-01-01

The ability to predict the consequences of an accidental release of radionuclides relies mainly on the level of understanding of the mechanisms involved in radionuclide interactions with different components of agricultural and natural ecosystems and their formalisation into predictive models. Numerous studies and databases on contaminated agricultural and natural areas have been obtained, but their use to enhance our prediction ability has been largely limited by their unresolved variability. Such variability seems to stem from incomplete knowledge about radionuclide interactions with the soil matrix, soil moisture, and biological elements in the soil and additional pollutants, which may be found in such soils. In the 5th European Framework Programme entitled Bioavailability of Radionuclides in Soils (BORIS), we investigated the role of the abiotic (soil components and soil structure) and biological elements (organic compounds, plants, mycorrhiza, and microbes) in radionuclide sorption/desorption in soils and radionuclide uptake/release by plants. Because of the importance of their radioisotopes, the bioavailability of three elements, caesium, strontium, and technetium has been followed. The role of one additional non-radioactive pollutant (copper) has been scrutinised in some cases. Role of microorganisms (e.g., K d for caesium and strontium in organic soils is much greater in the presence of microorganisms than in their absence), plant physiology (e.g., changes in plant physiology affect radionuclide uptake by plants), and the presence of mycorrhizal fungi (e.g., interferes with the uptake of radionuclides by plants) have been demonstrated. Knowledge acquired from these experiments has been incorporated into two mechanistic models CHEMFAST and BIORUR, specifically modelling radionuclide sorption/desorption from soil matrices and radionuclide uptake by/release from plants. These mechanistic models have been incorporated into an assessment model to enhance its

An overview of BORIS: Bioavailability of Radionuclides in Soils

Energy Technology Data Exchange (ETDEWEB)

Tamponnet, C. [Institute of Radioprotection and Nuclear Safety, DEI/SECRE, CADARACHE, B.P. 1, 13108 Saint-Paul-lez-Durance, Cedex (France)], E-mail: christian.tamponnet@irsn.fr; Martin-Garin, A.; Gonze, M.-A. [Institute of Radioprotection and Nuclear Safety, DEI/SECRE, CADARACHE, B.P. 1, 13108 Saint-Paul-lez-Durance, Cedex (France); Parekh, N. [Center for Ecology and Hydrology, Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom); Vallejo, R.; Sauras-Yera, T.; Casadesus, J. [Department of Plant Biology, University of Barcelona, 08028 Barcelona (Spain); Plassard, C.; Staunton, S. [INRA, UMR Rhizosphere and Symbiosis, Place Viala, 34060 Montpellier (France); Norden, M. [Swedish Radiation Protection Institute, 171 16 Stockholm (Sweden); Avila, R. [Facilia AB, Valsgaerdevaegen 12, 168 53 Bromma, Stockholm (Sweden); Shaw, G. [Division of Agricultural and Environmental Sciences University Park, Nottingham NG7 2RD (United Kingdom)

2008-05-15

The ability to predict the consequences of an accidental release of radionuclides relies mainly on the level of understanding of the mechanisms involved in radionuclide interactions with different components of agricultural and natural ecosystems and their formalisation into predictive models. Numerous studies and databases on contaminated agricultural and natural areas have been obtained, but their use to enhance our prediction ability has been largely limited by their unresolved variability. Such variability seems to stem from incomplete knowledge about radionuclide interactions with the soil matrix, soil moisture, and biological elements in the soil and additional pollutants, which may be found in such soils. In the 5th European Framework Programme entitled Bioavailability of Radionuclides in Soils (BORIS), we investigated the role of the abiotic (soil components and soil structure) and biological elements (organic compounds, plants, mycorrhiza, and microbes) in radionuclide sorption/desorption in soils and radionuclide uptake/release by plants. Because of the importance of their radioisotopes, the bioavailability of three elements, caesium, strontium, and technetium has been followed. The role of one additional non-radioactive pollutant (copper) has been scrutinised in some cases. Role of microorganisms (e.g., K{sub d} for caesium and strontium in organic soils is much greater in the presence of microorganisms than in their absence), plant physiology (e.g., changes in plant physiology affect radionuclide uptake by plants), and the presence of mycorrhizal fungi (e.g., interferes with the uptake of radionuclides by plants) have been demonstrated. Knowledge acquired from these experiments has been incorporated into two mechanistic models CHEMFAST and BIORUR, specifically modelling radionuclide sorption/desorption from soil matrices and radionuclide uptake by/release from plants. These mechanistic models have been incorporated into an assessment model to enhance

Radionuclide cisternographic findings in patients with spontaneous intracranial hypotension

International Nuclear Information System (INIS)

Jung, Dong Jin; Kim, Jae Seung; Ryu, Jin Sook; Shin, Jung Woo; Im, Joo Hyuk; Lee, Myoung Chong; Jung, Sung Joo; Moon, Dae Hyuk; Lee, Hee Kyung

1998-01-01

Radionuclide cisternography may be helpful in understanding pathophysiology of postural headache and low CSF pressure in patients with spontaneous intracranial hypotension. The purpose of this study was to characterize radionuclide cisternogrpahic findings of spontaneous intracranial hypotension. The study population consists of 15 patients with spontaneous intracranial hypotension. Diagnosis was based on their clinical symptoms and results of lumbar puncture. All patients underwent radionuclide cisternography following injection of 111 to 222 MBq of Tc-99m DTPA into the lumbar subarachnoid space. Sequential images were obtained between 1/2 hour and 24 hour after the injection of Tc-99m DTPA. Radioactivity of the bladder, soft tissue uptake, migration of radionuclide in the subarachnoid space, and extradural leakage of radionuclide were evaluated according to the scan time. Radionuclide cisternogram showed delayed migration of radionuclide into the cerebral convexity (14/15), increased soft tissue uptake (11/15), and early visualization of bladder activity at 30 min (6/10) and 2 hr (13/13). Cisternography also demonstrated leakage site of CSF in 4 cases and 2 of these were depicted at 30min. Epidural blood patch was done in 11 patients and headache was improved in all cases. The characteristics findings of spontaneous intracranial hypotension were delayed migration of radionuclide and early visualization of the soft tissue and bladder activity. These scintigraphic findings suggest that CSF leakage rather than increased CSF absorption or decreased production may be the main pathophysiology of spontaneous intracranial hypotension. Early and multiple imaging including the bladder and soft tissue is required to observe the entire dynamics of radionuclide migration

Natural and anthropogenic radionuclide activity concentrations in the New Zealand diet.

Science.gov (United States)

Pearson, Andrew J; Gaw, Sally; Hermanspahn, Nikolaus; Glover, Chris N

2016-01-01

To support New Zealand's food safety monitoring regime, a survey was undertaken to establish radionuclide activity concentrations across the New Zealand diet. This survey was undertaken to better understand the radioactivity content of the modern diet and also to assess the suitability of the current use of milk as a sentinel for dietary radionuclide trends. Thirteen radionuclides were analysed in 40 common food commodities, including animal products, fruits, vegetables, cereal grains and seafood. Activity was detected for (137)Caesium, (90)Strontium and (131)Iodine. No other anthropogenic radionuclides were detected. Activity concentrations of the three natural radionuclides of Uranium and the daughter radionuclide (210)Polonium were detected in the majority of food sampled, with a large variation in magnitude. The maximum activity concentrations were detected in shellfish for all these radionuclides. Based on the established activity concentrations and ranges, the New Zealand diet contains activity concentrations of anthropogenic radionuclides far below the Codex Alimentarius guideline levels. Activity concentrations obtained for milk support its continued use as a sentinel for monitoring fallout radionuclides in terrestrial agriculture. The significant levels of natural and anthropogenic radionuclide activity concentrations detected in finfish and molluscs support undertaking further research to identify a suitable sentinel for New Zealand seafood monitoring. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Radionuclide solubility control by solid solutions

Energy Technology Data Exchange (ETDEWEB)

Brandt, F.; Klinkenberg, M.; Rozov, K.; Bosbach, D. [Forschungszentrum Juelich GmbH (Germany). Inst. of Energy and Climate Research - Nuclear Waste Management and Reactor Safety (IEK-6); Vinograd, V. [Frankfurt Univ. (Germany). Inst. of Geosciences

2015-07-01

The migration of radionuclides in the geosphere is to a large extend controlled by sorption processes onto minerals and colloids. On a molecular level, sorption phenomena involve surface complexation, ion exchange as well as solid solution formation. The formation of solid solutions leads to the structural incorporation of radionuclides in a host structure. Such solid solutions are ubiquitous in natural systems - most minerals in nature are atomistic mixtures of elements rather than pure compounds because their formation leads to a thermodynamically more stable situation compared to the formation of pure compounds. However, due to a lack of reliable data for the expected scenario at close-to equilibrium conditions, solid solution systems have so far not been considered in long-term safety assessments for nuclear waste repositories. In recent years, various solid-solution aqueous solution systems have been studied. Here we present state-of-the art results regarding the formation of (Ra,Ba)SO{sub 4} solid solutions. In some scenarios describing a waste repository system for spent nuclear fuel in crystalline rocks {sup 226}Ra dominates the radiological impact to the environment associated with the potential release of radionuclides from the repository in the future. The solubility of Ra in equilibrium with (Ra,Ba)SO{sub 4} is much lower than the one calculated with RaSO{sub 4} as solubility limiting phase. Especially, the available literature data for the interaction parameter W{sub BaRa}, which describes the non-ideality of the solid solution, vary by about one order of magnitude (Zhu, 2004; Curti et al., 2010). The final {sup 226}Ra concentration in this system is extremely sensitive to the amount of barite, the difference in the solubility products of the end-member phases, and the degree of non-ideality of the solid solution phase. Here, we have enhanced the fundamental understanding regarding (1) the thermodynamics of (Ra,Ba)SO{sub 4} solid solutions and (2) the

Transuranic radionuclides dispersed into the environment at accident sites, a bibliography

International Nuclear Information System (INIS)

Stoker, A.C.; Noshkin, V.E.; Wong, K.M.

1994-07-01

The purpose of this project was to compile a bibliography of references containing environmental transuranic radionuclide data. The authors intent was to identify those parameters affecting transuranic radionuclide transport that may be generic and those that may be dependent on chemical form and/or environmental conditions. An understanding of the unique characteristics and similarities between source terms and environmental conditions relative to transuranic radionuclide transport and cycling will provide the ability to assess and predict the long term impact on man and the environment. An additional goal of the literature review, was to extract the ranges of environmental transuranic radionuclide data from the identified references for inclusion in a data base. Related to source term, these ranges of data can be used to calculate the dose to man from the radionuclides, and to perform uncertainty analyses on these dose assessments

The rocky flats controversy on radionuclide soil action levels

International Nuclear Information System (INIS)

Earle, T.C.

2004-01-01

This report describes the Rocky Flats radionuclide soil action level controversy as a case study for the purpose of understanding the nature and value of stakeholder involvement in the management of radiological hazards. The report consists of three main sections. The first section outlines the Rocky Flats story, including the Cold War era, the post-Cold War era, and the transition between the two. This provides the context necessary to understand the radionuclide soil action level controversy, the main events of which are described in the second section. In the final section, the Rocky Flats case is briefly discussed within the framework of a general model of stakeholder involvement and the lessons learned from the case are identified. (author)

Modeling of radiation doses from chronic aqueous releases

International Nuclear Information System (INIS)

Watts, J.R.

1976-01-01

A general model and corresponding computer code were developed to calculate personnel dose estimates from chronic releases via aqueous pathways. Potential internal dose pathways are consumption of water, fish, crustacean, and mollusk. Dose prediction from consumption of fish, crustacean, or mollusk is based on the calculated radionuclide content of the water and applicable bioaccumulation factor. 70-year dose commitments are calculated for whole body, bone, lower large intestine of the gastrointestinal tract, and six internal organs. In addition, the code identifies the largest dose contributor and the dose percentages for each organ-radionuclide combination in the source term. The 1974 radionuclide release data from the Savannah River Plant were used to evaluate the dose models. The dose predicted from the model was compared to the dose calculated from radiometric analysis of water and fish samples. The whole body dose from water consumption was 0.45 mrem calculated from monitoring data and 0.61 mrem predicted from the model. Tritium contributed 99 percent of this dose. The whole body dose from fish consumption was 0.20 mrem calculated from monitoring data and 0.14 mrem from the model. Cesium-134,137 was the principal contributor to the 70-year whole body dose from fish consumption

A literature survey of mineral-specific sorption data on radionuclides with relevance to the disposal of radioactive waste

International Nuclear Information System (INIS)

Delakowitz, B.; Meinrath, G.; Spiegel, W.

1996-01-01

A comparative review of mineral-specific radionuclide sorption databases created for performance assessment and reported in both the open literature and 'grey literature' (e.g. technical reports) has in part shown poor quality of documentation describing the database selection procedures. Inadequate information is available on the chemical species of the radionuclide under consideration and the laboratory conditions for determining K d -values. Sorption data derived from literature are neither comparable nor generally applicable due to the wide range in the composition of the aqueous and the solid phase applied in migration experiments. Subsequently, standardized characterization and determination procedures are needed. To improve the reliability of a mathematical model for the prediction of radionuclide sorption on cementitious and ash-type binder materials, determination of mineral-specific sorption coefficients is indispensable. (author). 31 refs., 1 fig., 2 tabs

Determination of radionuclide solubility limits to be used in SR 97. Uncertainties associated to calculated solubilities

Energy Technology Data Exchange (ETDEWEB)

Bruno, J.; Cera, E.; Duro, L.; Jordana, S. [QuantiSci S.L., Barcelona (Spain); Pablo, J. de [DEQ-UPC, Barcelona (Spain); Savage, D. [QuantiSci Ltd., Henley-on-Thames (United Kingdom)

1997-12-01

The thermochemical behaviour of 24 critical radionuclides for the forthcoming SR97 PA exercise is discussed. The available databases are reviewed and updated with new data and an extended database for aqueous and solid species of the radionuclides of interest is proposed. We have calculated solubility limits for the radionuclides of interest under different groundwater compositions. A sensitivity analysis of the calculated solubilities with the composition of the groundwater is presented. Besides selecting the most likely solubility limiting phases, in this work we have used coprecipitation approaches in order to calculate more realistic solubility limits for minor radionuclides, such as Ra, Am and Cm. The comparison between the calculated solubilities and the concentrations measured in relevant natural systems (NA) and in spent fuel leaching experiments helps to assess the validity of the methodology used and to derive source term concentrations for the radionuclides studied. The uncertainties associated to the solubilities of the main radionuclides involved in the spent nuclear fuel have also been discussed in this work. The variability of the groundwater chemistry; redox conditions and temperature of the system have been considered the main factors affecting the solubilities. In this case, a sensitivity analysis has been performed in order to study solubility changes as a function of these parameters. The uncertainties have been calculated by including the values found in a major extent in typical granitic groundwaters. The results obtained from this analysis indicate that there are some radionuclides which are not affected by these parameters, i.e. Ag, Cm, Ho, Nb, Ni, Np, Pu, Se, Sm, Sn, Sr, Tc and U

Tumour therapy with radionuclides: assessment of progress and problems

International Nuclear Information System (INIS)

Carlsson, Joergen; Forssell Aronsson, Eva; Hietala, Sven-Ola; Stigbrand, Torgny; Tennvall, Jan

2003-01-01

Radionuclide therapy is a promising modality for treatment of tumours of haematopoietic origin while the success for treatment of solid tumours so far has been limited. The authors consider radionuclide therapy mainly as a method to eradicate disseminated tumour cells and small metastases while bulky tumours and large metastases have to be treated surgically or by external radiation therapy. The promising therapeutic results for haematological tumours give hope that radionuclide therapy will have a breakthrough also for treatment of disseminated cells from solid tumours. New knowledge related to this is continuously emerging since new molecular target structures are being characterised and the knowledge on pharmacokinetics and cellular processing of different types of targeting agents increases. There is also improved understanding of the factors of importance for the choice of appropriate radionuclides with respect to their decay properties and the therapeutic applications. Furthermore, new methods to modify the uptake of radionuclides in tumour cells and normal tissues are emerging. However, we still need improvements regarding dosimetry and treatment planning as well as an increased knowledge about the tolerance doses for normal tissues and the radiobiological effects on tumour cells. This is especially important in targeted radionuclide therapy where the dose rates often are lower than 1 Gy/h

Solvent extraction of radionuclides from aqueous tank waste

International Nuclear Information System (INIS)

Moyer, B.A.; Bonnesen, P.V.; Sachleben, R.A.

1997-01-01

This task aims toward the development of efficient solvent-extraction processes for the removal of the fission products 99 Tc, 90 Sr, and 137 Cs from alkaline tank wastes. Processes already developed or proposed entail direct treatment of the waste solution with the solvent and subsequent stripping of the extracted contaminants from the solvent into a dilute aqueous solution. Working processes to remove Tc(and SR) separately and Cs separately have been developed; the feasibility of a combined process is under investigation. Since Tc, Sr, and Cs will be vitrified together in the high-level fraction, however, a process that could separate Tc, Sr, and Cs simultaneously, as opposed to sequentially, potentially offers the greatest impact. A figure presents a simplified diagram of a proposed solvent-extraction cycle followed by three possible treatments for the stripping solution. Some degree of recycle of the stripping solution (option a) is expected. Simple evaporation (option c) is possible prior to vitrification; this offers the greatest possible volume reduction with simple operation and no consumption of chemicals, but it is energy intensive. However, if the contaminants are concentrated (option b) by fixed-bed technology, the energy penalty of evaporation can be avoided and vitrification facilitated without any additional secondary waste being produced

Development and testing of radionuclide transport models for fractured crystalline rock. An overview of the Nagra/JNC radionuclide retardation programme

International Nuclear Information System (INIS)

Ota, Kunio; Alexander, W.R.

2001-01-01

The joint Nagra/JNC radionuclide Retardation Programme has now been ongoing for more thean 10 years with the main aim of direct testing of radionuclide transport models for fractured crystalline rocks in as realistic a manner as possible. A large programme of field, laboratory and natural analogue studies has been carried out at the Grimsel Test Site in the central Swiss Alps. The understanding and modelling of both the processes and the structures influencing radionuclide transport in fractured crystalline rocks have matured as has the experimental technology, which has contributed to develop confidence in the applicability of the underlying research models in a repository performance assessment. In this report, the successes and set-backs of this programme are discussed as is the general approach to the thorough testing of the process models and of model assumptions. (author)

Speciation analysis of radionuclides

International Nuclear Information System (INIS)

Salbu, B.

2010-01-01

Full text: Naturally occurring and artificially produced radionuclides in the environment can be present in different physico-chemical forms (i. e. radionuclide species) varying in size (nominal molecular mass), charge properties and valence, oxidation state, structure and morphology, density, complexing ability etc. Low molecular mass (LMM) species are believed to be mobile and potentially bioavailable, while high molecular mass (HMM) species such as colloids, polymers, pseudocolloids and particles are considered inert. Due to time dependent transformation processes such as mobilization of radionuclide species from solid phases or interactions of mobile and reactive radionuclide species with components in soils and sediments, however, the original distribution of radionuclides deposited in ecosystems will change over time and influence the ecosystem behaviour. To assess the environmental impact from radionuclide contamination, information on radionuclide species deposited, interactions within affected ecosystems and the time-dependent distribution of radionuclide species influencing mobility and biological uptake is essential. The development of speciation techniques to characterize radionuclide species in waters, soils and sediments should therefore be essential for improving the prediction power of impact and risk assessment models. The present paper reviews fractionation techniques which should be utilised for radionuclide speciation purposes. (author)

Radionuclide migration in clayrock host formations for deep geological disposal of radioactive waste: advances in process understanding and up-scaling methods resulting from the EC integrated project `Funmig

Science.gov (United States)

Altmann, S.; Tournassat, C.; Goutelard, F.; Parneix, J. C.; Gimmi, T.; Maes, N.

2009-04-01

One of the ‘pillars' supporting Safety Cases for deep geological disposal of radioactive waste in clayrock formations is the knowledge base regarding radionuclide (Rn) retention by sorption and diffusion-driven transport which is why the EC integrated project ‘Funmig' focused a major part of its effort on advancing understanding of these two macroscopic phenomena. This talk presents some of the main results of this four year effort (2005-2008). One of the keys to understanding diffusion-driven transport of anionic and cationic radionuclide species in clayrocks lies in a detailed understanding of the phenomena governing Rn total concentration and speciation (dissolved, adsorbed) in the different types of pore spaces present in highly-compacted masses of permanently charged clay minerals. Work carried out on a specifically synthesized montmorillonite (a model for the clay mineral fraction in clayrocks) led to development, and preliminary experimental validation, of a conceptually coherent set of theoretical models (molecular dynamics, electrostatic double layer, thermodynamic) describing dissolved ion and water solvent behavior in this material. This work, complemented by the existing state of the art, provides a sound theoretical basis for explaining such important phenomena as anion exclusion, cation exchange and the diffusion behavior of anions, weakly sorbing cations and water tracers. Concerning the behavior of strongly sorbing and/or redox-reactive radionuclides in clay systems, project research improved understanding of the nature of sorption reactions and sorbed species structure for key radioelements, or analogues (U, Se, Eu, Sm, Yb, Nd) on the basal surfaces and in the interlayers of synthetic or purified clay minerals. A probable mechanism for Se(IV) retention by reduction to Se° in Fe2+-containing clays was brought to light; this same process was also studied on the Callovo-Oxfordien clayrock targeted by the French radwaste management program. The

Radionuclide getters in the near-field chemistry of repositories

International Nuclear Information System (INIS)

Holland, T.R.; Lee, D.J.

1993-01-01

The ultimate release of radionuclides from a radioactive waste repository will depend upon the natural and man-made barriers surrounding the site. An opportunity exists to enhance natural radionuclide retention through improved sorption, by the use of suitable additives applied to the repository backfill material. This programme of work was designed to identify problem isotopes, to search for suitable materials to enhance their retention and ultimately to provide, through experimental studies, an understanding of their effectiveness under repository conditions. (Author)

Quantitative radionuclide angiocardiography

International Nuclear Information System (INIS)

Scholz, P.M.; Rerych, S.K.; Moran, J.F.; Newman, G.E.; Douglas, J.M.; Sabiston, D.C. Jr.; Jones, R.H.

1980-01-01

This study introduces a new method for calculating actual left ventricular volumes and cardiac output from data recorded during a single transit of a radionuclide bolus through the heart, and describes in detail current radionuclide angiocardiography methodology. A group of 64 healthy adults with a wide age range were studied to define the normal range of hemodynamic parameters determined by the technique. Radionuclide angiocardiograms were performed in patients undergoing cardiac catherization to validate the measurements. In 33 patients studied by both techniques on the same day, a close correlation was documented for measurement of ejection fraction and end-diastolic volume. To validate the method of volumetric cardiac output calcuation, 33 simultaneous radionuclide and indocyanine green dye determinations of cardiac output were performed in 18 normal young adults. These independent comparisons of radionuclide measurements with two separate methods document that initial transit radionuclide angiocardiography accurately assesses left ventricular function

Review Paper of Radionuclide Monitoring in Food Sample

International Nuclear Information System (INIS)

Noor Fadzilah Yusof; Abdul Kadir Ishak; Wo, Y.M.; Nurrul Assyikeen Mohd Jaffary

2011-01-01

The uncontrolled release of radionuclides into the atmospheric and aquatic environments may occur as the result of a nuclear or radiological accident. Monitoring of the accidental release at its source and especially direct monitoring of the environmental contamination with radionuclides is necessary for assessment and application of public protective actions and longer term countermeasures as well as emergency workers' protection. In areas historically contaminated with long lived radionuclides monitoring it is essential to protect the public and substantiation of any radiological incidents. Also, dietary pathways can be contaminated with radioactive materials resulting from natural occurrence or man-made applications especially during routine operation, accidents and migration of radionuclides from radioactive waste disposal repositories into the biosphere. Therefore, efforts should be made to determine the presence of radionuclides in a potentially high radiation area especially in operational nuclear facilities. This paper will review the strategies for food monitoring that has been adapted in most countries to obtain baseline data for future reference. Also, this study is discussing the type of food selection commonly collected as sample for radionuclide analysis in different countries over the years. Sampling procedure and analysis also included in this review for better understanding of the analysis. Stake holders' involvement is considered as an important asset in the establishment of monitoring strategies. As a conclusion, future plans for food monitoring programme in Malaysia are recommended as a preparation to embark on the Nuclear Power Plant programme. (author)

Distribution and dynamics of radionuclides and stable elements in the coastal waters off Rokkasho Village, Japan, prior to the opening of a nuclear reprocessing facility. Part 1. Sedimentation flux of suspended particles and elimination of radionuclides and stable elements from seawater

International Nuclear Information System (INIS)

Kondo, K.; Kawabata, H.; Ueda, S.; Hasegawa, H.; Inaba, J.; Ohmomo, Y.; Mitamura, O.; Seike, Y.

2004-01-01

A nuclear fuel reprocessing facility is currently under construction in Rokkasho Village, Aomori, Japan. After completion and start-up, this facility will discharge radionuclides into the Pacific Ocean through an outlet pipe set on the seafloor offshore. For future assessments of the stability of these radionuclides in the environment, a sufficient understanding of the behavior of radionuclides in this ocean ecosystem before the start-up of the facility is necessary. To understand the processes by which radionuclides and various other types of elements are eliminated from seawater, we measured the sedimentation flux of suspended particles in the coastal waters off Rokkasho Village where the sea emissions pipes will be placed. (author)

Estimation of {sup 60}Co activity in trace levels from aqueous medium using Ocimum basilicum seeds

Energy Technology Data Exchange (ETDEWEB)

Sangurdekar, P R [Radiation Safety System Div., Bhabha Atomic Research Centre, Mumbai (India); Melo, J S; D' Souza, S F [Nuclear Agriculture and Biotechnology Div., Bhabha Atomic Research Centre, Mumbai (India)

2006-07-01

In the field of pollution control besides the need for devising techniques for remediation, it is equally essential to develop alternative techniques for monitoring pollution levels including radioactivity. In this perspective, a simple technique is described for determining radioactivity in aqueous samples using O. basilicum seeds based on its property to adsorb radionuclides

Behaviour of uranium series radionuclides in surface water (Crouzille, Limousin). Geochemical implications

International Nuclear Information System (INIS)

Moulin, J.

2008-06-01

Understanding natural radionuclides behaviour in surface water is a required step to achieve uranium mine rehabilitation and preserve water quality. The first objective of this thesis is to determine which are the radionuclides sources in a drinking water reservoir. The second objective is to improve the knowledge about the behaviour of uranium series radionuclides, especially actinium. The investigated site is a brook (Sagnes, Limousin, France) which floods a peat bog contaminated by a former uranium mine and which empties into the Crouzille lake. It allows studying radionuclides transport in surface water and radionuclides retention through organic substance or water reservoir. Radionuclides distribution in particulate, colloidal and dissolved phases is determined thanks to ultra-filtrations. Gamma spectrometry allows measuring almost all natural radionuclides with only two counting stages. However, low activities of 235 U series radionuclides impose the use of very low background well-type Ge detectors, such as those of the Underground Laboratory of Modane (France). Firstly, this study shows that no or few radionuclides are released by the Sagnes peat bog, although its radioactivity is important. Secondly, it provides details on the behaviour of uranium series radionuclides in surface water. More specifically, it provides the first indications of actinium solubility in surface water. Actinium's behaviour is very close to uranium's even if it is a little less soluble. (author)

Long-term environmental behaviour of radionuclides

Energy Technology Data Exchange (ETDEWEB)

Brechignac, F.; Moberg, L.; Suomela, M

2000-04-01

The radioactive pollution of the environment results from the atmospheric nuclear weapons testing (during the mid-years of twentieth century), from the development of the civilian nuclear industry and from accidents such as Chernobyl. Assessing the resulting radiation that humans might receive requires a good understanding of the long-term behaviour of radionuclides in the environment. This document reports on a joint European effort to advance this understanding, 3 multinational projects have been coordinated: PEACE, EPORA and LANDSCAPE. This report proposes an overview of the results obtained and they are presented in 6 different themes: (i) redistribution in the soil-plant system, (ii) modelling, (iii) countermeasures, (iv) runoff (v) spatial variations, and (vi) dose assessment. The long term behaviour of the radionuclides {sup 137}Cs, {sup 90}Sr and {sup 239-240}Pu is studied through various approaches, these approaches range from in-situ experiments designed to exploit past contamination events to laboratory simulations. A broad scope of different ecosystems ranging from arctic and boreal regions down to mediterranean ones has been considered. (A.C.)

Long-term environmental behaviour of radionuclides

International Nuclear Information System (INIS)

Brechignac, F.; Moberg, L.; Suomela, M.

2000-04-01

The radioactive pollution of the environment results from the atmospheric nuclear weapons testing (during the mid-years of twentieth century), from the development of the civilian nuclear industry and from accidents such as Chernobyl. Assessing the resulting radiation that humans might receive requires a good understanding of the long-term behaviour of radionuclides in the environment. This document reports on a joint European effort to advance this understanding, 3 multinational projects have been coordinated: PEACE, EPORA and LANDSCAPE. This report proposes an overview of the results obtained and they are presented in 6 different themes: i) redistribution in the soil-plant system, ii) modelling, iii) countermeasures, iv) runoff v) spatial variations, and vi) dose assessment. The long term behaviour of the radionuclides 137 Cs, 90 Sr and 239-240 Pu is studied through various approaches, these approaches range from in-situ experiments designed to exploit past contamination events to laboratory simulations. A broad scope of different ecosystems ranging from arctic and boreal regions down to mediterranean ones has been considered. (A.C.)

Development and testing of inorganic sorbents made by the internal gelation process for radionuclide and heavy metal separations

International Nuclear Information System (INIS)

Egan, B.Z.; Collins, J.L.; Anderson, K.K.; Chase, C.W.

1995-01-01

The objectives of this task are to develop, prepare, and test microspheres and granular forms of inorganic ion exchangers to remove radionuclides and heavy metals from waste streams occurring at various sites. Several inorganic materials, such as hexacyanoferrates, titanates, phosphates, and oxides have high selectivities and efficiencies for separating and removing radionuclides such as uranium, technetium, cesium, and strontium, and metals such as cobalt, silver, zinc, and zirconium from aqueous waste streams. However, these sorbents frequently exist only as powders and consequently are not readily adaptable to continuous processing such as column chromatography. Making these inorganic ion exchangers as microspheres or granular forms improves the flow dynamics for column operations and expands their practical applications. Microspheres of several materials have been prepared at ORNL, and the effectiveness of zirconium monohydrogen phosphate and hydrous titanium oxide microspheres for removing radionuclides from hot cell waste solutions has been demonstrated

The determination of radionuclides and heavy metals in the phosphogypsum

International Nuclear Information System (INIS)

Rajkovic, M. B.; Markovic, M.; Vladisavljevic, G. T.; Stevanovic, R.

1999-01-01

Phosphogypsum is a waste product in phosphoric acid production using dihydrate wet phosphoric process. The radioactivity of the phosphogypsum is a consequence of the presence of radionuclides resulting from uranium radioactive decay. Presence of uranium in some phosphorites and its concentration depend on their source and variety whether they are primary or secondary can be 10-400 ppm. Radioactivity determined for phosphogypsum confirmed the presence of radionuclides U and 226 Ra. For this reason the methods of purification of raw phosphogypsum have been developed. An aqueous sulfuric acid solution having a concentration of 28 percent was admixed with a concentrated sulfuric acid solutions containing dissolved therein of barium sulfate at the temperature of 105 0 C, the slurry was cooled at a temperature of 30 0 C-35 0 C and then filtered. This purified phosphogypsum can be used independently, as a substitute for natural gypsum, or mixed with the natural gypsum. The consideration of the phosphogypsum is necessary because of the removal (or at least the reducing) of the enormous spoil areas of phosphogypsum and the diminution of the pollution. (author)

Simulating Radionuclide Migrations of Low-level Wastes in Nearshore Environment

Science.gov (United States)

Lu, C. C.; Li, M. H.; Chen, J. S.; Yeh, G. T.

2016-12-01

Tunnel disposal into nearshore mountains was tentatively selected as one of final disposal sites for low-level wastes in Taiwan. Safety assessment on radionuclide migrations in far-filed may involve geosphere processes under coastal environments and into nearshore ocean. In this study the 3-D HYDROFEOCHE5.6 numerical model was used to perform simulations of groundwater flow and radionuclide transport with decay chains. Domain of interest on the surface includes nearby watersheds delineated by digital elevation models and nearshore seabed. As deep as 800 m below the surface and 400 m below sea bed were considered for simulations. The disposal site was located at 200m below the surface. Release rates of radionuclides from near-field was estimated by analytical solutions of radionuclide diffusion with decay out of engineered barriers. Far-field safety assessments were performed starting from the release of radionuclides out of engineered barriers to a time scale of 10,000 years. Sensitivity analyses of geosphere and transport parameters were performed to improve our understanding of safety on final disposal of low-level waste in nearshore environments.

A review of methodology for studying the transfer of radionuclides in marine foodchains

International Nuclear Information System (INIS)

Cross, F.A.; Renfro, W.C.; Gilat, E.

1975-01-01

Understanding the mechanisms by which radionuclides are cycled within marine foodchains is essential for predicting concentrations in harvestable seafoods, evaluating the role of organisms in redistributing radionuclides, and assessing radiation doses to populations. Because of the complex interactions within marine foodchains, detailed radioecological studies in contaminated natural ecosystems and carefully designed, long-term laboratory studies on experimental foodchains are both necessary. The report discusses some of the methodological problems involved in conducting field and laboratory studies on radionuclide transfer in marine foodchains. (author)

Geotrap: radionuclide migration in geologic, heterogeneous media. Summary of accomplishments

International Nuclear Information System (INIS)

2002-01-01

GEOTRAP - the OECD/NEA Project on Radionuclide Migration in Geologic, Heterogeneous Media - was carried out in the context of site evaluation and safety assessment of deep repository systems for long-lived radioactive waste. The project was created in 1996 with the aim of developing an understanding of, and modelling capability for, potential radionuclide migration. This report provides an overview of the project's main findings and accomplishments over its five-year life. This summary should help make the valuable information collected and generated by the GEOTRAP project accessible to a wide readership both within and outside the radioactive waste community.It is a reflection of the careful attention paid by this community to the question of radionuclide transport. (authors)

Modelling and prediction of radionuclide migration from shallow, subgrade nuclear waste facilities in arid environments

International Nuclear Information System (INIS)

Smith, A.; Ward, A.; Geldenhuis, S.

1986-01-01

Over the past fifteen years, prodigious efforts and significant advances have been made in methods of prediction of the migration rate of dissolved species in aqueous systems. Despite such work, there remain formidable obstacles in prediction of solute transport in the unsaturated zone over the long time periods necessarily related to the radionuclide bearing wastes. The objective of this paper is to consider the methods, issues and problems with the use of predictive solute transport models for radionuclide migration from nuclear waste disposal in arid environments, if and when engineering containment of the waste fails. Having considered the ability for long term solute prediction for a number of geological environments, the advantages of a disposal environment in which the solute transport process is diffusion controlled will be described

Preparation and application of attapulgite/iron oxide magnetic composites for the removal of U(VI) from aqueous solution

International Nuclear Information System (INIS)

Fan, Qiao-hui; Li, Ping; Chen, Yun-fei; Wu, Wang-suo

2011-01-01

Highlights: → We first synthesized ATP/IOM composites as an adsorbents for removal U(VI) from aqueous solution. → The sorption ability of ATP/IOM composites were obviously superior to ATP and iron oxides. → The prevalent species of U(VI) on ATP/IOM composites were =S s OUO 2 + and =S w OUO 2 (CO 3 ) 2 3- . → ATP/IOM composites could be a promising candidate for pre-concentration and immobilization of radionuclides from large volumes of aqueous solutions. - Abstract: Recently, magnetic sorbents have received considerable attention because of their excellent segregative features and sorption capacities. Herein, attapulgite/iron oxide magnetic (ATP/IOM) composites were prepared and characterized. The sorption results indicated that ATP/IOM composites were superior to ATP and iron oxides individually for the removal of U(VI) from aqueous solution. Based on X-ray photoelectron spectroscopy (XPS) analysis and surface complexation model, the main sorption species of U(VI) on ATP were =X 2 UO 2 0 below pH 4.0 and =S s OUO 2 + , =S w OUO 2 CO 3 - , and =S w OUO 2 (CO 3 ) 2 3- above pH 5.0. However the prevalent species on ATP/IOM composites were =S s OUO 2 + and =S w OUO 2 (CO 3 ) 2 3- over the observed pH range. ATP/IOM composites are a promising candidate for pre-concentration and immobilization of radionuclides from large volumes of aqueous solutions, as required for remediation purposes.

Natural and anthropogenic radionuclide activity concentrations in the New Zealand diet

International Nuclear Information System (INIS)

Pearson, Andrew J.; Gaw, Sally; Hermanspahn, Nikolaus; Glover, Chris N.

2016-01-01

To support New Zealand's food safety monitoring regime, a survey was undertaken to establish radionuclide activity concentrations across the New Zealand diet. This survey was undertaken to better understand the radioactivity content of the modern diet and also to assess the suitability of the current use of milk as a sentinel for dietary radionuclide trends. Thirteen radionuclides were analysed in 40 common food commodities, including animal products, fruits, vegetables, cereal grains and seafood. Activity was detected for 137 Caesium, 90 Strontium and 131 Iodine. No other anthropogenic radionuclides were detected. Activity concentrations of the three natural radionuclides of Uranium and the daughter radionuclide 210 Polonium were detected in the majority of food sampled, with a large variation in magnitude. The maximum activity concentrations were detected in shellfish for all these radionuclides. Based on the established activity concentrations and ranges, the New Zealand diet contains activity concentrations of anthropogenic radionuclides far below the Codex Alimentarius guideline levels. Activity concentrations obtained for milk support its continued use as a sentinel for monitoring fallout radionuclides in terrestrial agriculture. The significant levels of natural and anthropogenic radionuclide activity concentrations detected in finfish and molluscs support undertaking further research to identify a suitable sentinel for New Zealand seafood monitoring. - Highlights: • A radionuclide monitoring program was undertaken across the New Zealand food supply. • 40 food types were analysed for 13 radionuclides. • 137 Cs was present in 15% of foods (range: 0.05–0.44Bq/kg). • Anthropogenic radionuclides displayed compliance with international limits. • 210 Po, 234 U and 238 U were present in most foods with large ranges of activities.

Confinement and migration of radionuclides in deep geological disposal

International Nuclear Information System (INIS)

Poinssot, Ch.

2007-07-01

Disposing high level nuclear waste in deep disposal repository requires to understand and to model the evolution of the different repository components as well as radionuclides migration on time-frame which are well beyond the time accessible to experiments. In particular, robust and predictive models are a key element to assess the long term safety and their reliability must rely on a accurate description of the actual processes. Within this framework, this report synthesizes the work performed by Ch. Poinssot and has been prepared for the defense of his HDR (French university degree to Manage Research). These works are focused on two main areas which are (i) the long term evolution of spent nuclear fuel and the development of radionuclide source terms models, and (ii) the migration of radionuclides in natural environment. (author)

The use of some local plants for removal of radioactive and trace elements from aqueous media

International Nuclear Information System (INIS)

Al-Masri, M. S.; Amin, Y.; Al-Akel, B; Al-Naama, T.

2008-02-01

The removal of metal ions from aqueous solutions by biosorption plays an important role in water pollution control. In this study, dried leaves of Barbary, Jew's mallow and poplar, branches of poplar trees and creeping club as biomass for removal of toxic elements (Cd, Pb and U) and some radionuclides ( 133 Ba, 137 Cs and 226 Ra) from aqueous solution have been evaluated. The results show that all studied plants can be effectively used for removing U and Ba from aqueous solutions, while Pb was removed using branches of poplar trees. In addition, Cd was removed using Barbary, Jew's mallow and branches of poplar trees. The adsorption of U and Cd by leaves of Barbary reached 3.3 mg g -1 and 3.5 mg g -1 , respectively. Moreover, the leaves of poplar trees were the best plant for biosorping Pb, its maximum capacity reached a value 1.7 mg g -1 . On the other hand, the maximum capacity for studied radionuclide was less than 10-6 mg g -1 . Further more, the effect of many factors such as, plant pretreatment, solution temperature, pH, plant particles size and contact time, on biosorption process were performed and the best conditions of biosorption were recognized. The studied plants were used for removing 226 Ra and some trace elements from real polluted water. The results show that the method is effective.(author)

Radionuclide fixation mechanisms in rocks

International Nuclear Information System (INIS)

Nakashima, S.

1991-01-01

In the safety evaluation of the radioactive waste disposal in geological environment, the mass balance equation for radionuclide migration is given. The sorption of radionuclides by geological formations is conventionally represented by the retardation of the radionuclides as compared with water movement. In order to quantify the sorption of radionuclides by rocks and sediments, the distribution ratio is used. In order to study quantitatively the long term behavior of waste radionuclides in geological environment, besides the distribution ratio concept in short term, slower radionuclide retention reaction involving mineral transformation should be considered. The development of microspectroscopic method for long term reaction path modeling, the behavior of iron during granite and water interaction, the reduction precipitation of radionuclides, radionuclide migration pathways, and the representative scheme of radionuclide migration and fixation in rocks are discussed. (K.I.)

Transfer of radionuclides to animal products following ingestion or inhalation

International Nuclear Information System (INIS)

Coughtrey, P.J.

1996-01-01

Contamination of animal products forms an important pathway in the transfer of radionuclides from source to man. Simulation of radionuclide transfer via animal products requires an understanding of the processes and mechanisms involved in absorption, distribution, turnover and excretion of radionuclides and related elements in animals as well as knowledge of animal grazing habits and husbandry. This paper provides a summary of the metabolism of important radionuclides in typical domestic animals and of the mathematical approaches that have been used to simulate transfer from diet to animal product. The equilibrium transfer factor approach has been used widely but suffers a number of disadvantages when releases or intakes are variable with time or when intakes are short relative to the lifetime of the animal of interest. Dynamic models, especially those of the compartmental type, have been developed and used widely. Both approaches have benefited from experiences obtained after the Chernobyl accident but a number of uncertainties still exist. Whereas there is now extensive knowledge on the behaviour of radiocaesium in both domestic and wild animals, knowledge of the behaviour of other potentially important radionuclides remains limited. Further experimental and metabolic studies will be required to reduce uncertainties associated with the transfer of radionuclides other than radiocaesium and thereby produce a sound basis for radiological assessments. (author)

Optimal beta-ray shielding thicknesses for different therapeutic radionuclides and shielding materials

International Nuclear Information System (INIS)

Cho, Yong In; Kim, Ja Mee; Kim, Jung Hoon

2017-01-01

To better understand the distribution of deposited energy of beta and gamma rays according to changes in shielding materials and thicknesses when radionuclides are used for therapeutic nuclear medicine, a simulation was conducted. The results showed that due to the physical characteristics of each therapeutic radionuclide, the thicknesses of shielding materials at which beta-ray shielding takes place varied. Additional analysis of the shielding of gamma ray was conducted for radionuclides that emit both beta and gamma rays simultaneously with results showing shielding effects proportional to the atomic number and density of the shielding materials. Also, analysis of bremsstrahlung emission after beta-ray interactions in the simulation revealed that the occurrence of bremsstrahlung was relatively lower than theoretically calculated and varied depending on different radionuclides. (authors)

CASCADER: An M-chain gas-phase radionuclide transport and fate model

International Nuclear Information System (INIS)

Cawlfield, D.E.; Emer, D.F.; Lindstrom, F.T.; Shott, G.J.

1993-09-01

Chemicals and radionuclides move either in the gas-phase, liquid-phase, or both phases in soils. They may be acted upon by either biological or abiotic processes through advection and/or dispersion. Additionally during the transport of parent and daughter radionuclides in soil, radionuclide decay may occur. This version of CASCADER called CASCADR9 starts with the concepts presented in volumes one and three of this series. For a proper understanding of how the model works, the reader should read volume one first. Also presented in this volume is a set of realistic scenarios for buried sources of radon gas, and the input and output file structure for CASCADER9

Aspects of uranium/thorium series disequilibrium applications to radionuclide migration studies

International Nuclear Information System (INIS)

Ivanovich, M.

1989-11-01

The aim of this paper is to consider the contribution which the uranium/thorium series disequilibrium concept can make to understanding the retardation and transport of radionuclides in the far-field of a radioactive waste repository. In principle, naturally occurring isotopes of uranium, thorium and radium can be regarded as geochemical analogues of the divalent radionuclides and multivalent actinides expected to be present in the radioactive waste inventory. The study of their retardation and/or transport in real rock/water systems which have taken place over geological timescales, can make an important contribution to establishing a rational basis for long-term predictive modelling of radionuclide transport required for safety assessments. (author)

Marine biogeochemistry of radionuclides

International Nuclear Information System (INIS)

Fowler, S.W.

1997-01-01

Radionuclides entering the ocean from runoff, fallout, or deliberate release rapidly become involved in marine biogeochemical cycles. Sources, sinks and transport of radionuclides and analogue elements are discussed with emphasis placed on how these elements interact with marine organisms. Water, food and sediments are the source terms from which marine biota acquire radionuclides. Uptake from water occurs by surface adsorption, absorption across body surfaces, or a combination of both. Radionuclides ingested with food are either assimilated into tissue or excreted. The relative importance of the food and water pathway in uptake varies with the radionuclide and the conditions under which exposure occurs. Evidence suggests that, compared to the water and food pathways, bioavailability of sediment-bound radionuclides is low. Bioaccumulation processes are controlled by many environmental and intrinsic factors including exposure time, physical-chemical form of the radionuclide, salinity, temperature, competitive effects with other elements, organism size, physiology, life cycle and feeding habits. Once accumulated, radionuclides are transported actively by vertical and horizontal movements of organisms and passively by release of biogenic products, e.g., soluble excreta, feces, molts and eggs. Through feeding activities, particles containing radionuclides are ''packaged'' into larger aggregates which are redistributed upon release. Most radionuclides are not irreversibly bound to such particles but are remineralized as they sink and/or decompose. In the pelagic zones, sinking aggregates can further scavenge particle-reactive elements thus removing them from the surface layers and transporting them to depth. Evidence from both radiotracer experiments and in situ sediment trap studies is presented which illustrates the importance of biological scavenging in controlling the distribution of radionuclides in the water column. (author)

Aqueous corrosion of borosilicate glasses. Nature and properties of alteration layers

International Nuclear Information System (INIS)

Trotignon, Laurent

1990-01-01

This research thesis addresses physical and chemical processes which occur during aqueous corrosion of silicates, and the study of the properties of their interfaces with solutions, and thus issues related to the fate of high activity nuclear wastes which are embedded in a vitreous matrix as the potential release of radionuclides towards the environment then depends on the glass parcel behaviour submitted to chemical attacks which could alter it, notably by aqueous corrosion. The objective is then to model the dissolution of nuclear glass over long periods of time, and to predict the behaviour of radionuclides. The author compared the corrosion and alteration layers of gradually more complex borosilicate glasses, from a ternary sodium borosilicate glass to a simulated nuclear glass (the French reference glass R7T7). Complexity is increased by adding oxides. After some theoretical recalls on the structure and corrosion of borosilicate glasses, the author presents the studied materials, the corrosion experiments, and analytical techniques used to study alteration layers. The mechanism of formation of altered layers is studied based on corrosion experiments performed at 90 C on the whole set of glasses. Alteration layers formed on corroded glasses are studied and compared by using various techniques: electronic microscopy, high energy ion beams, spectroscopy, infrared, photo-electron spectroscopy. Implications for underground storage of nuclear glasses are discussed

A study on the characteristics of colloid-associated radionuclide transport in porous media

International Nuclear Information System (INIS)

Jeong, Yun Chang

1997-02-01

Recently, the radionuclide transport in the form of colloids has been focused intensively in the safety assessment of a radioactive waste repository. As colloids are considered to be able to increase the transport rate of radionuclide through geologic media, the transport of radionuclide should be adjusted by the presence of colloids. The migration of dissolved radionuclide is expected to depend on various process such as advection, dispersion and interactions with soils, and, in addition, the transport of colloid-mediated radionuclide is considered to be more complicated because of the interactions between radionuclides and colloids. In this paper the migration behavior of colloid-associated radionuclides within subsurface are reviewed and studied in detail. The colloid-mediated transport system was modelled and simulated in order to illustrate the effects of colloids on the transport of radionuclide in the aquifer system. The transport rate of radionuclide is mainly controlled by a retardation factor which is controlled by colloidal behaviors, degree of adsorption, and the related geologic parameters. Therefore it is necessary to carefully understand the accelerating tendency of the retardation difference factor, and in this study the trends are analyzed, described and the retardation difference factor is mathematically defined, simplified and applied practically to the safety and performance assessment of a future repository

Formation and properties of radiocolloids in aqueous solution - a literature survey

International Nuclear Information System (INIS)

Olofsson, U.; Allard, B.; Andersson, K.; Torstenfelt, B.

1981-06-01

The sorption of radionuclides on various rocks and minerals has been studied within many national waste programs as a means of predicting the migration behaviour of radionuclides that might be released from e.g. an underground repository for radioactive waste. One major objection against the conclusions that can be drawn from laboratory sorption studies is that the possibility of a formation of small fractions of highly mobile particulates are usually not considered. The elements, present in spent nuclear fuel, which are most likely to form colloid species would be hydrolyzable elements like the actinides and possibly Sr as well as Pb and Cu representing the encapsulation material. Moreover the radionuclides would be present in aqueous solutions in very low concentrations and under these conditions other phenomena occurs than at macroconcentrations. This literature survey is meant to be a basis for further studies on the formation and transport of radiocolloids in the groundwater-rock environment. The colloids will probably not be retarded by the same mechanisms as dissolved species in true solution, but may in some cases migrate with the same velocity as the groundwater. (Auth.)

Fully coupled modeling of radionuclide migration in a clayey rock disturbed by alkaline plume

International Nuclear Information System (INIS)

Pellegrni, D.; Windt, L. de; Lee, J.V.D.

2002-03-01

The disposal of radioactive wastes in clayey formations may require the use of large amounts of concrete and cement as a barrier to minimize corrosion of steel containers and radionuclide migration and for supporting drifts and disposal vaults. In this context, reactive transport modeling of the interactions between cement or concrete and the argillaceous host rock aims at estimating the evolution in time of the containment properties of the multi-barriers system. The objectives of the paper are to demonstrate that integrating radionuclides migration in the modeling of strongly coupled geochemical processes of cement-clay stone interactions is feasible and that it represents an efficient way to assess the sensitivity and modification of the classical Kd and solubility parameters with respect to the chemical evolutions. Two types of modeling are considered in the paper: i): calculation of intrinsic solubility limits and Kd values backing up on the results of modeling of cement/clay stone interactions (radionuclides are assumed to be present over the whole domain at any time whatever the scenario), ii) full mechanistic modeling which explicitly introduces radionuclides in the calculation with ad hoc assumptions on radionuclide inventory, canister failure, migration pathway, etc. The reactive transport code HYTEC, based on the geochemical code CHESS, is used to simulate both the cement-clay stone interaction processes and the radionuclide migration in 1-D and 2-D configurations. Convective/dispersive and diffuse transport can be simulated for solutes and colloids. A wide range of processes such as aqueous chemistry, redox, dissolution/precipitation, surface complexation and ion exchange can be modeled at equilibrium or with kinetic control. In addition, HYTEC is strongly coupled, i.e. the hydrology (flow and diffusion) may change when mineral precipitation or dissolution changes the local porosity. (authors)

Radionuclide Incorporation and Long Term Performance of Apatite Waste Forms

Energy Technology Data Exchange (ETDEWEB)

Wang, Jianwei [Louisiana State Univ., Baton Rouge, LA (United States); Lian, Jie [Rensselaer Polytechnic Inst., Troy, NY (United States); Gao, Fei [Univ. of Michigan, Ann Arbor, MI (United States)

2016-01-04

This project aims to combines state-of-the-art experimental and characterization techniques with atomistic simulations based on density functional theory (DFT) and molecular dynamics (MD) simulations. With an initial focus on long-lived I-129 and other radionuclides such as Cs, Sr in apatite structure, specific research objectives include the atomic scale understanding of: (1) incorporation behavior of the radionuclides and their effects on the crystal chemistry and phase stability; (2) stability and microstructure evolution of designed waste forms under coupled temperature and radiation environments; (3) incorporation and migration energetics of radionuclides and release behaviors as probed by DFT and molecular dynamics (MD) simulations; and (4) chemical durability as measured in dissolution experiments for long term performance evaluation and model validation.

On the role of water and forage in penetration of some radionuclides into the Limnaea organism

International Nuclear Information System (INIS)

Marchyulenene, D.P.; Polikarpov, G.G.; AN Ukrainskoj SSR, Sevastopol. Inst. Biologii Yuzhnykh Morej)

1976-01-01

The objective of this work was to study under laboratory conditions the significance of elodea (Elodea canadensis Rich.) and aqueous medium in accumulation of strontium-90, cesium-137, cerium-144 and ruthenium-106 by limnetic gastropods (Limnaea Stagnalis L.). The study revealed that only 2 and 5% of strontium-90 and cerium-144 respectively were accumulated in molluscs shell from radioactive food, and 4 and 26% - in the body. The authors believed that higher accumulation levels of cerium-144 and ruthenium-106 in mollusca body when the molluscs are fed with radioactive elodea were caused by high accumulation coefficients (AC) of radionuclides in food, i.e. elodea, and their accumulation in the gastrointestinal tracts of molluscs. To appreciates the significance of elodea and water as sources of radionuclide accumulation by mollusca, strontium-90 and cerium-144 AC in molluscs were estimated in relation to water and elodea. The results obtained indicated that AC of these radionuclides in mollusca was much lower in relation to food than to water

Separation Techniques for Quantification of Radionuclides in Environmental Samples

Directory of Open Access Journals (Sweden)

Dusan Galanda

2009-01-01

Full Text Available The reliable and quantitative measurement of radionuclides is important in order to determine environmental quality and radiation safety, and to monitor regulatory compliance. We examined soil samples from Podunajske Biskupice, near the city of Bratislava in the Slovak Republic, for the presence of several natural (238U, 232Th, 40K and anthropogenic (137Cs, 90Sr, 239Pu, 240Pu, 241Am radionuclides. The area is adjacent to a refinery and hazardous waste processing center, as well as the municipal incinerator plant, and so might possess an unusually high level of ecotoxic metals. We found that the levels of both naturally occurring and anthropogenic radionuclides fell within the expected ranges, indicating that these facilities pose no radiological threat to the local environment. During the course of our analysis, we modified existing techniques in order to allow us to handle the unusually large and complex samples that were needed to determine the levels of 239Pu, 240Pu, and 241Am activity. We also rated three commercial techniques for the separation of 90Sr from aqueous solutions and found that two of them, AnaLig Sr-01 and Empore Extraction Disks, were suitable for the quantitative and reliable separation of 90Sr, while the third, Sr-Spec Resin, was less so. The main criterion in evaluating these methods was the chemical recovery of 90Sr, which was less than we had expected. We also considered speed of separation and additional steps needed to prepare the sample for separation.

Verification and improvement of predictive algorithms for radionuclide migration

International Nuclear Information System (INIS)

Carnahan, C.L.; Miller, C.W.; Remer, J.S.

1984-01-01

This research addresses issues relevant to numerical simulation and prediction of migration of radionuclides in the environment of nuclear waste repositories. Specific issues investigated are the adequacy of current numerical codes in simulating geochemical interactions affecting radionuclide migration, the level of complexity required in chemical algorithms of transport models, and the validity of the constant-k/sub D/ concept in chemical transport modeling. An initial survey of the literature led to the conclusion that existing numerical codes did not encompass the full range of chemical and physical phenomena influential in radionuclide migration. Studies of chemical algorithms have been conducted within the framework of a one-dimensional numerical code that simulates the transport of chemically reacting solutes in a saturated porous medium. The code treats transport by dispersion/diffusion and advection, and equilibrium-controlled proceses of interphase mass transfer, complexation in the aqueous phase, pH variation, and precipitation/dissolution of secondary solids. Irreversible, time-dependent dissolution of solid phases during transport can be treated. Mass action, transport, and sorptive site constraint equations are expressed in differential/algebraic form and are solved simultaneously. Simulations using the code show that use of the constant-k/sub D/ concept can produce unreliable results in geochemical transport modeling. Applications to a field test and laboratory analogs of a nuclear waste repository indicate that a thermodynamically based simulator of chemical transport can successfully mimic real processes provided that operative chemical mechanisms and associated data have been correctly identified and measured, and have been incorporated in the simulator. 17 references, 10 figures

Radionuclide generators

International Nuclear Information System (INIS)

Lambrecht, R.M.; Wollongong Univ.; Tomiyoshi, K.; Sekine, T.

1997-01-01

The present status and future directions of research and development on radionuclide generator technology are reported. The recent interest to develop double-neutron capture reactions for production of in vivo generators; neutron rich nuclides for radio-immunotherapeutic pharmaceuticals: and advances with ultra-short lived generators is highlighted. Emphasis is focused on: production of the parent radionuclide; the selection and the evaluation of support materials and eluents with respect to the resultant radiochemical yield of the daughter, and the breakthrough of the radionuclide parent: and, the uses of radionuclide generators in radiopharmaceutical chemistry, biomedical and industrial applications. The 62 Zn → 62 Cu, 66 Ni → 66 Cu, 103m Rh → 103 Rh, 188 W → 188 Re and the 225 Ac → 221 Fr → 213 Bi generators are predicted to be emphasized for future development. Coverage of the 99 Mo → 99m Tc generator was excluded, as it the subject of another review. The literature search ended June, 1996. (orig.)

Extension of Studies with 3M Empore TM and Selentec MAG *SEP SM Technologies for Improved Radionuclide Field Sampling

International Nuclear Information System (INIS)

Beals, D.M.; Bibler, J.P.; Brooks, D.A.

1996-01-01

The Savannah River Technology Center is evaluating new field sampling methodologies to more easily determine concentrations of radionuclides in aqueous systems. One methodology studied makes use of 3M EmporeTM disks. The disks are composed of selective resins embedded in a Teflon support. The disks remove the ion of interest from aqueous solutions when the solution is passed through the disk. The disk can then be counted directly to quantify the isotope of interest. Four types of disks were studied during this work: for the extraction of technetium (two types), cesium, plutonium, and strontium. A sampler has been developed for automated, unattended, in situ use of the EmporeTM disks

Extension of Studies with 3M Empore TM and Selentec MAG *SEP SM Technologies for Improved Radionuclide Field Sampling

Energy Technology Data Exchange (ETDEWEB)

Beals, D.M. [Westinghouse Savannah River Company, AIKEN, SC (United States); Bibler, J.P.; Brooks, D.A.

1996-07-10

The Savannah River Technology Center is evaluating new field sampling methodologies to more easily determine concentrations of radionuclides in aqueous systems. One methodology studied makes use of 3M EmporeTM disks. The disks are composed of selective resins embedded in a Teflon support. The disks remove the ion of interest from aqueous solutions when the solution is passed through the disk. The disk can then be counted directly to quantify the isotope of interest. Four types of disks were studied during this work: for the extraction of technetium (two types), cesium, plutonium, and strontium. A sampler has been developed for automated, unattended, in situ use of the EmporeTM disks.

Radionuclides in the oceans inputs and inventories

International Nuclear Information System (INIS)

Guegueniat, P.; Germain, P.; Metivier, H.

1996-01-01

Ten years after Chernobyl, following the decision by France to end nuclear weapon testing in the Pacific ocean, after the end of the OECD-NEA Coordinated Research and Environmental Surveillance programme related to low-level waste dumping in the deep ocean, and one hundred years after the discovery of radioactivity, the IPSN wanted to compile and review the available information on artificial radioactivity levels in seas and oceans. International experts have been invited to present data on inputs and inventories of radionuclides in the marine environment, and to describe the evolution of radioactivity levels in water, sediments and living organisms. Different sources of radionuclides present in the aquatic environment are described: atmospheric fallout before and after Chernobyl, industrial wastes, dumped wastes and ships, nuclear ship accidents, river inputs, earth-sea atmospheric transfers and experimental sites for nuclear testing. Radioactivity levels due to these sources are dealt with at ocean (Atlantic, Pacific and Indian) and sea level (Channel, North Sea, Irish Sea, Mediterranean, Baltic, Black Sea and Arctic seas). These data collected in the present book give an up-to-date assessment of radionuclide distributions which will be very useful to address scientific and wider public concerns about radionuclides found in the aquatic environment. It gives many references useful to those who want to deepen their understanding of particular aspects of marine radioecology. (authors)

The treatment of radioactive aqueous wastes by reverse osmosis

International Nuclear Information System (INIS)

Hodgson, T.D.

Experiments were carried out to determine the rejection factors for the more important radionuclides found in aqueous wastes, to study activity deposition within reverse osmosis modules, and to obtain experience in active operation of a reverse osmosis facility. It was found that reverse osmosis is likely to be useful in aqueous radioactive waste treatment when a wide range of contaminants rather than a specific radioactive species must be removed. There appeared to be no barrier to active operation, although greater confidence in the reliability of pumps and membranes is needed. The rejection of trace quantities of radioisotopes such as Cs + or Sr ++ could be predicted from the behaviour of similar inactive ions. Activity present as polyvalent ions or colloidal aggregates is highly rejected by the membrane. Activity may be deposited onto the membrane with insoluble or scaling compounds, and is greatest on areas of the membrane shielded from the sweeping action of the liquor flow

Novel diagnostic and therapeutic radionuclides for the development of innovative radiopharmaceuticals

CERN Multimedia

We propose the exploration of novel radionuclides with diagnostic or therapeutic properties from ISOLDE. Access to such unique isotopes will enable the fundamental research in radiopharmaceutical science towards superior treatment, e.g. in nuclear oncology. The systematic investigation of the biological response to the different characteristics of the decay radiation will be performed for a better understanding of therapeutic effects. The development of alternative diagnostic tools will be applied for the management and optimization of radionuclide therapy.

Forecast of radionuclides release from actual waste form geometries

International Nuclear Information System (INIS)

Suarez, A.A.; Rzyski, B.M.; Sato, I.M.

1989-01-01

The complete understanding of the leaching mechanism of radionuclides from solid comentitious waste forms is still far from being reached. Much effort has been devoted, however, to identifying and explaining the main components which contribute to the dispersal of radionuclides out of the waste form to the environment. This is of prime importance when short term results are extrapolated into the future. The diffusion coefficient evaluation, based on experimental leaching data obtained from samples produced from the same batch was performed using the exact diffusion formulation applied to real geometric sample shape. This paper discusses the evaluation

Radionuclides in terrestrial ecosystems

International Nuclear Information System (INIS)

Allen, S.E.; Horrill, A.D.; Howard, B.J.; Lowe, V.P.W.; Parkinson, J.A.

1983-07-01

The subject is discussed under the headings: concentration and spatial distribution of radionuclides in grazed and ungrazed saltmarshes; incorporation of radionuclides by sheep grazing on an estuarine saltmarsh; inland transfer of radionuclides by birds feeding in the estuaries and saltmarshes at Ravenglass; radionuclides in contrasting types of coastal pastures and taken up by individual plant species found in west Cumbria; procedures developed and used for the measurement of alpha and gamma emitters in environmental materials. (U.K.)

Uptake of γ-emitting radionuclides by aquatic biota exposed to contaminated water before and after passage through the ground

International Nuclear Information System (INIS)

Cushing, C.E.; Rickard, W.H.; Watson, D.G.

1984-01-01

Three experimental systems were designed to investigate the differential accumulation of radionuclides by biota from low-level aqueous effluents after passage through the ground. One system received river water (control), one received dilute low-level radioactive effluents (trench), and the third received the low-level effluents after it had percolated through about 260 m or porous gravel (springs). Biota studied included filamentous green algae, clams (Corbicula), goldfish (Carassius auratus), carp (Cyprinus carpio), and Veronica. Trophic level differences in accumulation of the various radionuclides from the diluted trench water were not consistent but generally followed the pattern algae > goldfish > molluscs > carp. Cobalt-60 was accumulated to the highest level of any radionuclide, and accumulation levels at the three sites were directly related to the concentration of 60 Co in the water. Manganese-54, 59 Fe, and 106 Ru were also accumulated to measurable levels in biota at the springs site indicating their bioavailability after passage through the ground

Radionuclide synovectomy – essentials for rheumatologists

Directory of Open Access Journals (Sweden)

Marek M. Chojnowski

2016-07-01

Full Text Available Radionuclide synovectomy is a minimally invasive method of treating persistent joint inflammation. It involves intra-articular injection of radioactive colloids which induce necrosis and fibrosis of hypertrophic synovial membrane. The most common indication for radiosynovectomy is rheumatoid arthritis, although patients with seronegative spondyloarthropathies, unclassified arthritis, haemophilic arthropathy and other less common arthropathies can also benefit from this method. Radiosynovectomy is safe, well tolerated and efficacious. About 70–80% of patients respond well to the therapy. However, the therapeutic effects are considerably worse in patients with co-existent osteoarthritis and advanced joint degeneration. Despite its advantages, radionuclide synovectomy is not performed as often as it could be, so greater knowledge and understanding of this method are needed. The authors present the most important facts about radiosynovectomy that may help rheumatologists in their daily clinical practice.

Radionuclide data

International Nuclear Information System (INIS)

Anon.

1992-01-01

Chapter 8 presents tables on selected alpha, beta, gamma and x-ray emitters by increasing energy; information on specific activity for selected radionuclides; naturally occurring radionuclides; the natural decay series; and the artificially produced neptunium series. A table of alpha emitters is listed by increasing atomic number and by energy. The table of β emitters presented is useful in identifying β emitters whose energies and possibly half-lives have been determined by standard laboratory techniques. It is also a handy guide to β-emitting isotopes for applications requiring specific half-lives and/or energies. Gamma rays for radionuclides of importance to radiological assessments and radiation protection are listed by increasing energy. The energies and branching ratios are important for radionuclide determinations with gamma spectrometry detectors. This section also presents a table of x-ray energies which are useful for radiochemical analyses. A number of nuclides emit x-rays as part of their decay scheme. These x-rays may be counted with Ar proportional counters, Ge planar or n-type Ge co-axial detectors, or thin crystal NaI(T1) scintillation counters. In both cases, spectral measurements can be made and both qualitative and quantitative information obtained on the sample. Nuclear decay data (energy and probability by radiation type) for more than one hundred radionuclides that are important to health physicists are presented in a schematic manner

Characterisation of discharge areas of radionuclides originating from nuclear waste repositories

International Nuclear Information System (INIS)

Marklund, L.; Woerman, A.

2008-01-01

In this study, we investigate if there are certain landscape elements that will generally act as discharge areas for radio-nuclides leaking from a subsurface deposit of nuclear waste. We also characterize the typical properties that distinguish these areas from others. Understanding the processes controlling the clustering of discharge to certain areas is an additional topic of study. Landscape topography is the most important driving force for groundwater flow. Because groundwater is the main transporting agent for migrating radio-nuclides, the topography will determine the flow paths of leaking radionuclides. How topography and heterogeneities in the subsurface affect the discharge distribution of the radionuclides is the main scope of this study. An analytical and a numerical model are used. Conclusions are: Our results suggest that the varieties of landscape elements which have potential for receiving significant amounts of radio-nuclides are limited. To save recourses, the surficial radiological assessments should therefore be focused in these areas. Furthermore, the discharge areas of groundwater from repository depth have defining characteristics that distinguish them from discharge areas of shallower groundwater flow cells. Due to the similarities within deep groundwater discharge areas, one can make site-specific analyses of those areas, which have a broad applicability for migration of radio-nuclides originating from a nuclear waste repository (author)(tk)

Performance analysis of numeric solutions applied to biokinetics of radionuclides

International Nuclear Information System (INIS)

Mingatos, Danielle dos Santos; Bevilacqua, Joyce da Silva

2013-01-01

Biokinetics models for radionuclides applied to dosimetry problems are constantly reviewed by ICRP. The radionuclide trajectory could be represented by compartmental models, assuming constant transfer rates between compartments. A better understanding of physiological or biochemical phenomena, improve the comprehension of radionuclide behavior in the human body and, in general, more complex compartmental models are proposed, increasing the difficulty of obtaining the analytical solution for the system of first order differential equations. Even with constant transfer rates numerical solutions must be carefully implemented because of almost singular characteristic of the matrix of coefficients. In this work we compare numerical methods with different strategies for ICRP-78 models for Thorium-228 and Uranium-234. The impact of uncertainty in the parameters of the equations is also estimated for local and global truncation errors. (author)

Environmental effects of radionuclides - observations on natural ecosystems

International Nuclear Information System (INIS)

Copplestone, D.; Toal, M.E.; Johnson, M.S.; Jackson, D.; Jones, S.R.

2000-01-01

To better quantify risk to non-human species from exposure to environmental radioactivity, understanding of the behaviour of radionuclides in the biosphere needs to be increased. This study outlines current thinking on ecological risk assessment (ERA) methodology and applies the indicator species or critical groups approach to biota inhabiting a semi-natural coniferous woodland contaminated with the radionuclides 137 Cs, 238 Pu, 239+240 Pu and 241 Am. The majority of these radionuclides originate from routine aerial emissions from the nuclear fuel reprocessing plant at BNFL, Sellafield, Cumbria, UK. Radionuclide activity concentrations have been determined in biota from the woodland and estimates of absorbed dose rates (mGy d -1 ) have been calculated using the dosimetric models outlined. Dose rates to the key indicator species, Oniscus asellus, Carabus violaceous and Apodemus sylvaticus (detritivorous invertebrate, predatory invertebrate and the granivorous wood mouse) have been determined at 3.0x10 -3 mGy d -1 , 2.2x10 -3 mGy d -1 and 1.0x10 -3 mGy d -1 respectively. The values are at least three orders of magnitude lower than the 1 mGy d -1 level below which no observable effects on populations in a terrestrial ecosystem are thought to occur. Limitations of this approach are discussed. (author)

Environmental effects of radionuclides--observations on natural ecosystems.

Science.gov (United States)

Copplestone, D; Toal, M E; Johnson, M S; Jackson, D; Jones, S R

2000-03-01

To better quantify risk to non-human species from exposure to environmental radioactivity, understanding of the behaviour of radionuclides in the biosphere needs to be increased. This study outlines current thinking on ecological risk assessment (ERA) methodology and applies the indicator species or critical groups approach to biota inhabiting a semi-natural coniferous woodland contaminated with the radionuclides 137Cs, 238Pu, 239+240Pu and 241Am. The majority of these radionuclides originate from routine aerial emissions from the nuclear fuel reprocessing plant at BNFL, Sellafield, Cumbria, UK. Radionuclide activity concentrations have been determined in biota from the woodland and estimates of absorbed dose rates (mGy d(-1)) have been calculated using the dosimetric models outlined. Dose rates to the key indicator species, Oniscus asellus, Carabus violaceous and Apodemus sylvaticus (detritivorous invertebrate, predatory invertebrate and the granivorous wood mouse) have been determined at 3.0 x 10(-3) mGy d(-1), 2.2 x 10(-3) mGy d(-1) and 1.0 x 10(-3) mGy d(-1) respectively. The values are at least three orders of magnitude lower than the 1 mGy d(-1) level below which no observable effects on populations in a terrestrial ecosystem are thought to occur. Limitations of this approach are discussed.

Hydrology and Radionuclide Migration Program, 1985--1986 progress report

International Nuclear Information System (INIS)

Buddemeier, R.W.

1988-09-01

This report presents results from the Lawrence Livermore National Laboratory's participation in the Hydrology and Radionuclide Migration Program (formerly the Radionuclide Migration Project) at the Nevada Test Site (NTS) during fiscal years 1985 and 1986. The report discusses studies of the partitioning and movement of dissolved and colloidal radionuclides at the Cheshire (U20n) site; tracer studies of shallow recharge and of plant-water uptake at the Cambric-site ditch carrying the effluent water pumped from well RNM-2; development of a rapid and sensitive assay for 99 Tc in groundwater and its application to a survey of technetium activities at a variety of test wells; and a series of methodological studies directed toward calibration, understanding, and improving our low-level radionuclide determinations. Groundwater sampled from the Cheshire cavity and from adjacent aquifers contains substantial concentrations (mg/L) of colloids that appear to consist primarily of natural minerals. These colloids were found to contain detectable amounts of strongly sorbed radionuclides, leading to the hypothesis that radionuclides are being transported by the groundwater in colloidal form. The RNM ditch at the Cambric site has provided a unique tritium-labeled, irrigated test plot in the desert. One study at this site continued earlier investigations of water and tritium migration in the shallow vadose (unsaturated-soil) zone adjacent to the ditch and extended that study to include using a tracer to determine the velocity of vertical water flow in the recharge zone directly below the ditch. 57 refs., 15 figs., 23 tabs

Radionuclide generators

International Nuclear Information System (INIS)

Lambrecht, R.M.

1983-01-01

The status of radionuclide generators for chemical research and applications related to the life sciences and biomedical research are reviewed. Emphasis is placed upon convenient, efficient and rapid separation of short-lived daughter radionuclides in a chemical form suitable for use without further chemical manipulation. The focus is on the production of the parent, the radiochemistry associated with processing the parent and daughter, the selection and the characteristic separation methods, and yields. Quality control considerations are briefly noted. The scope of this review includes selected references to applications of radionuclide generators in radiopharmaceutical chemistry, and the life sciences, particularly in diagnostic and therapeutic medicine. The 99 Mo-sup(99m)Tc generator was excluded. 202 references are cited. (orig.)

Radionuclide transfer from soil to agricultural plants: measurements and modelling

International Nuclear Information System (INIS)

Sabbarese, C; Terrasi, F.; D'Onofrio, A.D.; Stellato, L.; Lubritto, C.; Ermice, A.; Cotrufo, M.F.

2002-01-01

To assess the internal doses to humans from ingestion of radionuclides present in agricultural products it is necessary to know the main processes which determine the transport of radionuclides in the environment (Russel, 1966; Peterson, 1983; IAEA, 1995). The available data, generally, do not reflect natural conditions, and the mechanisms of translocation and mobility of radionuclides within the soil-plant system are still not fully understood (Coughtrey and Thorne, 1983; Fresquez et a., 1998; Krouglov et al., 1997; Frissel, 1992; Roca and Vallejo, 1995; Desmet et al., 1990). The knowledge of the contributions of direct contamination of plant fruits and of the process of root to fruit transfer can improve the understanding of exposure through ingestion and of the mechanisms determining sorption and translocation. Several studies on the relations among specific activities of various radionuclides in different environmental compartments have been performed in the last decades (Coughtrey and Thorne, 1983; Fresquez et al., 1998; Krouglov et al., 1997; Howard et al., 1995; Strand et al., 1994; Konshin, 1992; Frissel, 1992; Alexakhin and Korneev, 1992; Desmet et al., 1990)

Overview of CEA research in the field of radionuclides migration

International Nuclear Information System (INIS)

Poinssot, Ch.; Trotignon, L.; Tevissen, E.

2006-01-01

This report presents a synthetic status of the researches conducted within the Nuclear Energy Division (CEA/DEN) in the field of radionuclides migration in three specific areas which have been chosen for their representativeness and potential impact: the migration of RN in PWR reactors, the migration of RN from a deep geological repository and the migration processes in the surface environments. In addition, some status is given about more generic research which is conducted in the field of RN speciation in the aqueous phase and at the interfaces and regarding chemistry / transport couplings. Additional information about the human and technical means involved in these fields of research in CEA/DEN is finally given in the Appendix. (authors)

Models and data to predict radionuclide concentrations in river basin systems

International Nuclear Information System (INIS)

Fleming, G.; Rufai, G.G.

1990-01-01

Radioactive contamination of land may result from the detonation of nuclear weapons or nuclear accidents, such as Chernobyl. The deposition of fallout on soil and/or plants, and subsequent erosion by rainsplash and overland flow, could introduce radioactive isotopes into the water and soil resources of the environment. A model to simulate the transport and deposition of concentrated pollutants and radionuclides within the river basin is proposed. The proposed model is built on an existing Strathclyde River Basin Model, (SRBM), which has the potential to simulate runoff and erosion and the distribution of eroded soil particle sizes. An algorithm of the processes of concentration of pollutants and radionuclides can be developed based on the current understanding of the process of radionuclide attachment to soil particles. (author)

Radionuclides in radiation-induced bystander effect; may it share in radionuclide therapy?

Science.gov (United States)

Widel, M

2017-01-01

For many years in radiobiology and radiotherapy predominated the conviction that cellular DNA is the main target for ionizing radiation, however, the view has changed in the past 20 years. Nowadays, it is assumed that not only directed (targeted) radiation effect, but also an indirect (non-targeted) effect may contribute to the result of radiation treatment. Non-targeted effect is relatively well recognized after external beam irradiation in vitro and in vivo, and comprises such phenomena like radiation-induced bystander effect (RIBE), genomic instability, adaptive response and abscopal (out of field) effect. These stress-induced and molecular signaling mediated phenomena appear in non-targeted cells as variety responses resembling that observed in directly hit cells. Bystander effects can be both detrimental and beneficial in dependence on dose, dose-rate, cell type, genetic status and experimental condition. Less is known about radionuclide-induced non-targeted effects in radionuclide therapy, although, based on characteristics of the radionuclide radiation, on experiments in vitro utilizing classical and 3-D cell cultures, and preclinical study on animals it seems obvious that exposure to radionuclide is accompanied by various bystander effects, mostly damaging, less often protective. This review summarizes existing data on radionuclide induced bystander effects comprising radionuclides emitting beta- and alpha-particles and Auger electrons used in tumor radiotherapy and diagnostics. So far, separation of the direct effect of radionuclide decay from crossfire and bystander effects in clinical targeted radionuclide therapy is impossible because of the lack of methods to assess whether, and to what extent bystander effect is involved in human organism. Considerations on this topic are also included.

Radionuclides retention: from macroscopic to microscopic

International Nuclear Information System (INIS)

Simoni, E.

2002-01-01

In order to determine the radionuclides' sorption constants on solid natural minerals, both thermodynamic and structural investigations, using spectroscopic techniques, are presented. The natural clays, that could be used as engineering barriers in the nuclear waste geological repository, are rather complex minerals. Therefore, in order to understand how these natural materials retain the radionuclides, it is necessary first to perform these studies on simple substrates such as single crystal, oxides and silicates, and then extrapolate the obtained results on the natural minerals. We examine in this paper the sorption processes of the hexavalent uranium on zircon (ZrSiO 4 ) and the trivalent curium on a natural clay (bentonite). The corresponding sorption curves are simulated using the results obtained with the following spectroscopic techniques: laser induced spectro-fluorimetry, X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (EXAFS), diffuse reflectance infrared Fourier transform (DRIFT). (authors)

Radionuclide cardiography in medical practice

International Nuclear Information System (INIS)

Strangfeld, D.; Mohnike, W.; Schmidt, J.; Heine, H.; Correns, H.J.

1986-01-01

This publication is a compendium on all aspects of radionuclide diagnostics concerning cardiovascular system diseases. Starting with introductory remarks on the control of cardiovascular diseases the contribution of radionuclide cardiology to functional cardiovascular diagnostics as well as pathophysiological and pathobiochemical aspects of radiocardiography are outlined. Radiopharmaceuticals used in radiocardiography, physical and technical problems in application of radionuclides and their measuring techniques are discussed. In individual chapters radionuclide ventriculography, myocardial scintiscanning, circulatory diagnostics, radionuclide diagnostics of arterial hypertension, of thrombosis and in vitro diagnostics of thrombophilia are treated in the framework of clinical medicine

Metabolism of radionuclides in domestic animals

International Nuclear Information System (INIS)

Wirth, E.; Leising, C.

1986-01-01

The reactor accident at Chernobyl has shown that shortly after the contamination of the environment radionuclides can be found in animal products. The main contamination pathways of domestic animas are: uptake of radionuclides by foodstuffs; uptake of radionuclides by contaminated drinking water; uptake of radionuclides by inhalation; uptake of radionuclides through skin; uptake of radionuclides by ingestion of soil particles. Generally the uptake of radionuclides by food is the dominant exposure pathway. In rare cases the inhalation of radionuclides or the uptake by drinking water may be of importance. The metabolism of incorporated radionuclides is comparable to the respective metabolism of essential mass or trace elements or heavy metals. Radioisotopes of essential elements are for instance iron 55, manganese 54, cobalt 58 and cobalt 60. Other elements are typical antagonists to essential elements, e.g. strontium 90 is an antagonist to calcium or cesium 137 to potassium. Lead 210 and plutonium 239 behave similarly as heavy metals. Generally the knowledge of the metabolism of trace and mass elements, of antagonistic and synergistic elements and heavy metals can be applied to these radionuclides

Radionuclide scanning

International Nuclear Information System (INIS)

Shapiro, B.

1986-01-01

Radionuclide scanning is the production of images of normal and diseased tissues and organs by means of the gamma-ray emissions from radiopharmaceutical agents having specific distributions in the body. The gamma rays are detected at the body surface by a variety of instruments that convert the invisible rays into visible patterns representing the distribution of the radionuclide in the body. The patterns, or images, obtained can be interpreted to provide or to aid diagnoses, to follow the course of disease, and to monitor the management of various illnesses. Scanning is a sensitive technique, but its specificity may be low when interpreted alone. To be used most successfully, radionuclide scanning must be interpreted in conjunction with other techniques, such as bone radiographs with bone scans, chest radiographs with lung scans, and ultrasonic studies with thyroid scans. Interpretation is also enhanced by providing pertinent clinical information because the distribution of radiopharmaceutical agents can be altered by drugs and by various procedures besides physiologic and pathologic conditions. Discussion of the patient with the radionuclide scanning specialist prior to the study and review of the results with that specialist after the study are beneficial

Naturally occurring radionuclides transfer factor on aquatic flora and fauna in Nagarjuna Sagar Dam near proposed uranium mining site

International Nuclear Information System (INIS)

Arunachalam, Kantha Deivi

2015-04-01

Naturally occurring radioactive element can be found in low levels within all rock, soil, and water. The present work aims to understand the transfer of naturally occurring radionuclides in different compartments of environment reflecting its behaviour in different tropic levels. The understanding and evaluation of the possible interactions of various naturally occurring radionuclides were done in the world's third largest man-made dam, Nagarjuna Sagar, built on river Krishna located in Andhra Pradesh, India. The naturally occurring radionuclides such as Uranium ( 238 U), Polonium ( 210 Po), Radium ( 226 Ra), and Lead ( 210 Pb) were analyzed in different matrices (i.e) sediment, water, and fish. The measurement of the naturally occurring radionuclides in the environment can be used as a reference baseline for long-term monitoring in the entire aquatic ecosystem

Drift-Scale Radionuclide Transport

International Nuclear Information System (INIS)

Houseworth, J.

2004-01-01

The purpose of this model report is to document the drift scale radionuclide transport model, taking into account the effects of emplacement drifts on flow and transport in the vicinity of the drift, which are not captured in the mountain-scale unsaturated zone (UZ) flow and transport models ''UZ Flow Models and Submodels'' (BSC 2004 [DIRS 169861]), ''Radionuclide Transport Models Under Ambient Conditions'' (BSC 2004 [DIRS 164500]), and ''Particle Tracking Model and Abstraction of Transport Process'' (BSC 2004 [DIRS 170041]). The drift scale radionuclide transport model is intended to be used as an alternative model for comparison with the engineered barrier system (EBS) radionuclide transport model ''EBS Radionuclide Transport Abstraction'' (BSC 2004 [DIRS 169868]). For that purpose, two alternative models have been developed for drift-scale radionuclide transport. One of the alternative models is a dual continuum flow and transport model called the drift shadow model. The effects of variations in the flow field and fracture-matrix interaction in the vicinity of a waste emplacement drift are investigated through sensitivity studies using the drift shadow model (Houseworth et al. 2003 [DIRS 164394]). In this model, the flow is significantly perturbed (reduced) beneath the waste emplacement drifts. However, comparisons of transport in this perturbed flow field with transport in an unperturbed flow field show similar results if the transport is initiated in the rock matrix. This has led to a second alternative model, called the fracture-matrix partitioning model, that focuses on the partitioning of radionuclide transport between the fractures and matrix upon exiting the waste emplacement drift. The fracture-matrix partitioning model computes the partitioning, between fractures and matrix, of diffusive radionuclide transport from the invert (for drifts without seepage) into the rock water. The invert is the structure constructed in a drift to provide the floor of the

Measurement of some water quality parameters related to natural radionuclides in aqueous environmental samples from former tin mining lake

International Nuclear Information System (INIS)

Zaini Hamzah; Masitah Alias; Ahmad Saat; Abdul Kadir Ishak

2011-01-01

The issue of water quality is a never ended issue and becoming more critical when considering the presence of natural radionuclides. Physical parameters and the levels of radionuclides may have some correlation and need further attention. In this study, the former tin mine lake in Kampong Gajah was chosen as a study area for its past historical background which might contribute to attenuation of the levels of natural radionuclides in water. The water samples were collected from different lakes using water sampler and some in-situ measurement were conducted to measure physical parameters as well as surface dose level. The water samples were analyzed for its gross alpha and gross beta activity concentrations using liquid scintillation counting and in-house cocktail method. Gross alpha and beta analyzed using in-house cocktail are in the range of 3.17 to 8.20 Bq/ L and 9.89 to 22.20 Bq/ L; 1.64 to 8.78 Bq/ L and 0.22 to 28.22 Bq/ L, respectively for preserved and un-preserved sample. The surface dose rate measured using survey meter is in the range of 0.07 to 0.21 μSv/ h and 0.07 to 0.2 μSv/ h for surface and 1 meter above the surface of the water, respectively. (Author)

Environmental effects of radionuclides - observations on natural ecosystems

Energy Technology Data Exchange (ETDEWEB)

Copplestone, D. [Industrial Ecology Research Centre, School of Biological Sciences, University of Liverpool, Liverpool L69 3BX (United Kingdom). E-mail: copplest at liv.ac.uk; Toal, M.E.; Johnson, M.S. [Industrial Ecology Research Centre, School of Biological Sciences, University of Liverpool, Liverpool L69 3BX (United Kingdom); Jackson, D.; Jones, S.R. [Westlakes Scientific Consulting, Princess Royal Building, Westlakes Science and Technology Park, Moor Row, Cumbria CA24 3LN (United Kingdom)

2000-03-01

To better quantify risk to non-human species from exposure to environmental radioactivity, understanding of the behaviour of radionuclides in the biosphere needs to be increased. This study outlines current thinking on ecological risk assessment (ERA) methodology and applies the indicator species or critical groups approach to biota inhabiting a semi-natural coniferous woodland contaminated with the radionuclides {sup 137}Cs, {sup 238}Pu, {sup 239+240}Pu and {sup 241}Am. The majority of these radionuclides originate from routine aerial emissions from the nuclear fuel reprocessing plant at BNFL, Sellafield, Cumbria, UK. Radionuclide activity concentrations have been determined in biota from the woodland and estimates of absorbed dose rates (mGy d{sup -1}) have been calculated using the dosimetric models outlined. Dose rates to the key indicator species, Oniscus asellus, Carabus violaceous and Apodemus sylvaticus (detritivorous invertebrate, predatory invertebrate and the granivorous wood mouse) have been determined at 3.0x10{sup -3} mGy d{sup -1}, 2.2x10{sup -3} mGy d{sup -1} and 1.0x10{sup -3} mGy d{sup -1} respectively. The values are at least three orders of magnitude lower than the 1 mGy d{sup -1} level below which no observable effects on populations in a terrestrial ecosystem are thought to occur. Limitations of this approach are discussed. (author)

Chapter 2. Radionuclides in the biosphere

International Nuclear Information System (INIS)

Toelgyessy, J.; Harangozo, M.

2000-01-01

This is a chapter of textbook of radioecology for university students. In this chapter authors deal with role of radionuclides in the biosphere. Chapter consists of next parts: (1) Natural radionuclides in biosphere; (2) Man-made radionuclides in the biosphere; (3) Ecologically important radionuclides; (4) Natural background; (5) Radiotoxicity and (6) Paths of transfer of radionuclides from the source to human

Health impacts of large releases of radionuclides. Proceedings

International Nuclear Information System (INIS)

Lake, J.V.; Bock, G.R.; Cardew, Gail

1997-01-01

There have been various large-scale releases of radionuclides into the environment in the 20th century. Some of these have been accidental and some deliberate. In order to minimize the risk to human health of such releases, it is important that we understand how these substances are transported throughout the terrestrial and aquatic environments and the ways in which they can ultimately affect human health. This book contains contributions from the world's leading radioecologists and health scientists who discuss the progress in understanding these transport processes and exposure pathways of radionuclides to humans; the problems and latest techniques of quantitating retrospectively the actual doses received by individuals; the time course of effects of exposure in relation to structure and function at the cellular tissue, organ and whole organism level; the genetic effects, and effects on reproductive health, in populations and individuals, including fetal effects in pregnant women and inherited genetic effects; and scientific approaches to evaluate the important problem of the mental health consequences of perceived risk of radiation damage to health. (author)

Cosmogenic radionuclides. Theory and applications in the terrestrial and space environments

International Nuclear Information System (INIS)

Beer, Juerg; Steiger, Rudolf von; McCracken, Ken

2012-01-01

Cosmogenic radionuclides are radioactive isotopes which are produced by natural processes and distributed within the Earth system. With a holistic view of the environment the authors show in this book how cosmogenic radionuclides can be used to trace and to reconstruct the history of a large variety of processes. They discuss the way in which cosmogenic radionuclides can assist in the quantification of complex processes in the present-day environment. The book aims to demonstrate to the reader the strength of analytic tools based on cosmogenic radionuclides, their contribution to almost any field of modern science, and how these tools may assist in the solution of many present and future problems that we face here on Earth. The book provides a comprehensive discussion of the basic principles behind the applications of cosmogenic (and other) radionuclides as environmental tracers and dating tools. The second section of the book discusses in some detail the production of radionuclides by cosmic radiation, their transport and distribution in the atmosphere and the hydrosphere, their storage in natural archives, and how they are measured. The third section of the book presents a number of examples selected to illustrate typical tracer and dating applications in a number of different spheres (atmosphere, hydrosphere, geosphere, biosphere, solar physics and astronomy). At the same time the authors have outlined the limitations of the use of cosmogenic radionuclides. Written on a level understandable by graduate students without specialist skills in physics or mathematics, the book addresses a wide audience, ranging from archaeology, biophysics, and geophysics, to atmospheric physics, hydrology, astrophysics and space science.

Cosmogenic radionuclides. Theory and applications in the terrestrial and space environments

Energy Technology Data Exchange (ETDEWEB)

Beer, Juerg [Eidgenoessische Anstalt fuer Wasserversorgung, Abwasserreinigung und Gewaesserschutz, Duebendorf (Switzerland); Steiger, Rudolf von [International Space Science Insitute, Bern (Switzerland); McCracken, Ken [Maryland Univ., College Park (United States). IPST

2012-07-01

Cosmogenic radionuclides are radioactive isotopes which are produced by natural processes and distributed within the Earth system. With a holistic view of the environment the authors show in this book how cosmogenic radionuclides can be used to trace and to reconstruct the history of a large variety of processes. They discuss the way in which cosmogenic radionuclides can assist in the quantification of complex processes in the present-day environment. The book aims to demonstrate to the reader the strength of analytic tools based on cosmogenic radionuclides, their contribution to almost any field of modern science, and how these tools may assist in the solution of many present and future problems that we face here on Earth. The book provides a comprehensive discussion of the basic principles behind the applications of cosmogenic (and other) radionuclides as environmental tracers and dating tools. The second section of the book discusses in some detail the production of radionuclides by cosmic radiation, their transport and distribution in the atmosphere and the hydrosphere, their storage in natural archives, and how they are measured. The third section of the book presents a number of examples selected to illustrate typical tracer and dating applications in a number of different spheres (atmosphere, hydrosphere, geosphere, biosphere, solar physics and astronomy). At the same time the authors have outlined the limitations of the use of cosmogenic radionuclides. Written on a level understandable by graduate students without specialist skills in physics or mathematics, the book addresses a wide audience, ranging from archaeology, biophysics, and geophysics, to atmospheric physics, hydrology, astrophysics and space science.

Extraction behavior of radionuclides in the first separation cycle in reprocessing

International Nuclear Information System (INIS)

Uchiyama, Gunzo; Asakura, Toshihide; Hotoku, Shinobu; Watanabe, Makio; Fujine, Sachio; Nemoto, Hideyuki.

1997-01-01

The chemical flowsheet experiment by using three mixer-settlers was conducted to study the extraction behavior of radionuclides such as technetium, neptunium, iodine, zirconium and ruthenium in the uranium-TBP-nitric acid solution system in the simulated first separation cycle in current reprocessing plants. The following results were obtained: More than 99.999% of the total uranium fed to the co-decontamination step in the simulated dissolver solution was extracted by TBP solvent. About 90% of the total uranium was recovered in the uranium back-extraction step. About 30% of the total neptunium fed to the co-decontamination step was in the raffinate solution in the co-decontamination step, 12% of the total neptunium was in the Tc solution in the Tc separation step and about 58% of the total neptunium was in the Pu solution in the U/Pu partitioning step. As for technetium, about 99% of the total technetium was extracted by TBP in the co-decontamination step, 86% of the total technetium was scrubbed with high acid nitric acid solution in the Tc separation step and 13% of the total technetium was in the Pu solution in the U/Pu partitioning step. As for the other radionuclides, 99% of the total ruthenium and 93% of the total zirconium were distributed into the raffinate in the co-decontamination step. In the Tc separation step, ruthenium was scrubbed more effectively than ruthenium with high acid solution. About 45% of the total iodine fed to the co-decontamination step was vaporized during the experiment. Iodine in aqueous solutions in the flowsheet was mainly in volatile I 2 form. Iodine was rarely distributed into the aqueous solution and was distributed with TBP solvent in the flowsheet. Significant amounts of iodine was contained in the washed solvent. (author)

Geomorphological applications of environmental radionuclides

International Nuclear Information System (INIS)

Quine, T.A.; Walling, D.

1998-01-01

Geomorphologists have shown increasing interest in environmental radionuclides since pioneering studies by Ritchie and McHenry in the USA and Campbell, Longmore and Loughran in Australia. Environmental radionuclides have attracted this interest because they provide geomorphologists with the means to trace sediment movement within the landscape. They, therefore, facilitate investigation of subjects at the core of geomorphology, namely the rates and patterns of landscape change. Most attention has been focussed on the artificial radionuclide caesium-137 ( 137 Cs) but more recently potential applications of the natural radionuclides lead-210 ( 210 Pb) and beryllium-7( 7 Be) have been investigated (Walling et al., 1995; Wallbrink and Murray, 1996a, 1996b). The origin, characteristics and applications of these radionuclides are summarised. These radionuclides are of value as sediment tracers because of three important characteristics: a strong affinity for sediment; a global distribution and the possibility of measurement at low concentration. Geomorphological applications of environmental radionuclides provide unique access to detailed qualitative data concerning landscape change over a range of timescales

An independent method for data selection of long-life radionuclides (actinides and fission products) in the geosphere

International Nuclear Information System (INIS)

Henry, M.; Merceron, T.

1994-01-01

An independent method for data selection of long-life radio-nuclides based on the electronegativity equalization principle is proposed to predict the speciation of metal cations as a function of the solution pH. Hydrolysis, condensation and complexation reactions of metal cations in aqueous media are, by this simple model, unified and can be analyzed in terms of electronegativities, oxidation states and coordination numbers with a specific PC software. This paper describes the thermodynamical basis and the underlying concepts of the model in relation to aqueous actinide chemistry of elements such as U and Tc. It is then shown that the model could provide a complementary approach to existing softwares based on thermodynamic data bases allowing to make intelligent and reasonnable choices for the various complexes to consider in complex geochemical codes. (orig.)

Effect of different combining patterns of radionuclides in marine organisms

International Nuclear Information System (INIS)

Ueda, T.; Suzuki, Y.; Nakamura, R.; Nakahara, M.

1981-01-01

Information on the environmental factors (level of radioactivity in sea water, salinity, temperature, etc.), the biological factors (growth stage, species of organism, etc.), and the metabolism of radionuclides in marine organisms should be taken into account so as to understand the mechanism of radioactive contamination of marine organisms. From this viewpoint, the combining of radionuclides with constituents in marine organisms was studied, indicating the differences as follows: (a) Different appearances of radioactive cobalt in the liver of the abalone due to chemical forms: From the gel filtration profiles on Sephadex it was observed that 57 Co accumulated in the liver of the abalone from sea water labelled by complexed 57 Co combines with a constituent in the liver that has a molecular weight of about 40,000. However, 60 Co taken up from sea water containing ionic 60 Co combines with other constituents in the liver. (b) Appearance of radionuclides in fish due to pathways (sea water and food): In fish liver, most 137 Cs from both sea water and food combines with only one constituent substance; the molecular weight of this substance was estimated at 1100-1300. Cobalt-60 from both sea water and food associates with two different molecular weight constituents, but 65 Zn made a considerable difference in the gel filtration profiles between sea water and food. These results indicate that the metabolism of radionuclides in marine organisms may possibly be varied by the chemical forms of radionuclides in sea water and the pathways of radionuclides. (author)

Rest and exercise radionuclide angiography for diagnosis in chronic ischemic heart disease

International Nuclear Information System (INIS)

Gibbons, R.J.

1991-01-01

Rest and exercise radionuclide angiography is frequently employed for the diagnosis of chest pain syndromes. Its value and limitations in this regard have been well studied, but proper utilization of the technique requires an understanding of five critical concepts: (1) Radionuclide angiography is superior to treadmill exercise testing and probably equivalent to thallium scintigraphy, although the published series did not use current methods. (2) The true specificity of radionuclide angiography is about 80%, intermediate between the early optimistic estimates and the later pessimistic ones. (3) The peak exercise ejection fraction is the preferred test parameter for diagnosis, although exercise hemodynamics, symptoms, and electrocardiographic changes should also be considered. (4) Although radionuclide angiography is clearly helpful for noninvasive diagnosis, significant numbers of patients will continue to fall in an uncertain category. (5) The proper application of the technique requires recognition of its limitations and careful attention to technical details. When properly applied, this modality can make an important contribution to clinical decision making. 58 references

Foodstuffs, radionuclides, monitoring

International Nuclear Information System (INIS)

Denisikov, A.I.

2000-01-01

Radionuclide contamination of water and food stuffs as a result of the Chernobyl accident and permissible contents of 90 Sr and 137 Cs are considered in brief. A method of radiation monitoring of food stuffs and water for the radionuclides mentioned is suggested. The method permits employment of the simplest and cheapest radiometric equipment for analysis, whole the high degree of radionuclide concentration using fiber sorbents permits using the instrumentation without expensive shields against external radiation. A description of ion-exchange unit for radiation monitoring of liquid samples of food stuffs or water, is provided [ru

Generator for radionuclide

International Nuclear Information System (INIS)

Weisner, P.S.; Forrest, T.R.F.

1985-01-01

This invention provides a radionuclide generator of the kind in which a parent radionuclide, adsorbed on a column of particulate material, generates a daughter radionuclide which is periodically removed from the column. This invention is particularly concerned with technetium generators using single collection vials. The generator comprises a column, a first reservoir for the eluent, a second reservoir to contain the volume of eluent required for a single elution, and means connecting the first reservoir to the second reservoir and the second reservoir to the column. Such a generator is particularly suitable for operation by vacuum elution

[The assessment of radionuclide contamination and toxicity of soils sampled from "experimental field" site of Semipalatinsk nuclear test site].

Science.gov (United States)

Evseeva, T I; Maĭstrenko, T A; Belykh, E S; Geras'kin, S A; Kriazheva, E Iu

2009-01-01

Large-scale maps (1:25000) of soil contamination with radionuclides, lateral distribution of 137Cs, 90Sr, Fe and Mn water-soluble compounds and soil toxicity in "Experimental field" site of Semipalatinsk nuclear test site were charted. At present soils from studied site (4 km2) according to basic sanitary standards of radiation safety adopted in Russian Federation (OSPORB) do not attributed to radioactive wastes with respect to data on artificial radionuclide concentration, but they do in compliance with IAEA safety guide. The soils studied can not be released from regulatory control due to radioactive decay of 137Cs and 90Sr and accumulation-decay of 241Am up to 2106 year according to IAEA concept of exclusion, exemption and clearance. Data on bioassay "increase of Chlorella vulgaris Beijer biomass production in aqueous extract from soils" show that the largest part of soils from the studied site (74%) belongs to stimulating or insignificantly influencing on the algae reproduction due to water-soluble compounds effect. Toxic soils occupy 26% of the territory. The main factors effecting the algae reproduction in the aqueous extracts from soil are Fe concentration and 90Sr specific activity: 90Sr inhibits but Fe stimulates algae biomass production.

Results for the second quarter 2014 tank 50 WAC slurry sample chemical and radionuclide contaminants

International Nuclear Information System (INIS)

Bannochie, C.

2014-01-01

This report details the chemical and radionuclide contaminant results for the characterization of the 2014 Second Quarter sampling of Tank 50 for the Saltstone Waste Acceptance Criteria (WAC) in effect at that time. Information from this characterization will be used by DWPF & Saltstone Facility Engineering (DSFE) to support the transfer of low-level aqueous waste from Tank 50 to the Salt Feed Tank in the Saltstone Facility in Z-Area, where the waste will be immobilized. This information is also used to update the Tank 50 Waste Characterization System

Results for the Third Quarter 2014 Tank 50 WAC slurry sample: Chemical and radionuclide contaminants

Energy Technology Data Exchange (ETDEWEB)

Crawford, Charles L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2015-01-08

This report details the chemical and radionuclide contaminant results for the characterization of the 2014 Third Quarter sampling of Tank 50 for the Saltstone Waste Acceptance Criteria (WAC) in effect at that time.¹ Information from this characterization will be used by DWPF & Saltstone Facility Engineering (DSFE) to support the transfer of low-level aqueous waste from Tank 50 to the Salt Feed in the Saltstone Facility in Z-Area, where the waste will be immobilized. This information is also used to update the Tank 50 Waste Characterization System.

Results For The Fourth Quarter 2014 Tank 50 WAC Slurry Sample: Chemical And Radionuclide Contaminants

Energy Technology Data Exchange (ETDEWEB)

Crawford, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2015-09-30

This report details the chemical and radionuclide contaminant results for the characterization of the Calendar Year (CY) 2014 Fourth Quarter sampling of Tank 50 for the Saltstone Waste Acceptance Criteria (WAC) in effect at that time. Information from this characterization will be used by DWPF & Saltstone Facility Engineering (DSFE) to support the transfer of low-level aqueous waste from Tank 50 to the Salt Feed Tank in the Saltstone Facility in Z-Area, where the waste will be immobilized. This information is also used to update the Tank 50 Waste Characterization System.

Results For The Second Quarter 2013 Tank 50 WAC Slurry Sample: Chemical And Radionuclide Contaminants

Energy Technology Data Exchange (ETDEWEB)

Bannochie, Christopher J.

2013-07-31

This report details the chemical and radionuclide contaminant results for the characterization of the 2013 Second Quarter sampling of Tank 50 for the Saltstone Waste Acceptance Criteria (WAC) in effect at that time. Information from this characterization will be used by Saltstone Facility Engineering (SFE) to support the transfer of low-level aqueous waste from Tank 50 to the Salt Feed Tank in the Saltstone Facility in Z-Area, where the waste will be immobilized. This information is also used to update the Tank 50 Waste Characterization System.

Sorption behavior of cesium, cobalt and europium radionuclides onto hydroxyl magnesium silicate

Energy Technology Data Exchange (ETDEWEB)

Hamed, Mostafa M.; Holiel, M.; Ahmed, I.M. [Atomic Energy Authority, Cairo (Egypt). Hot Laboratories and Waste Management Center

2016-07-01

The radioactive wastes from different activities have to be safely disposed of and isolated from the human environment. The retardation of radioactive materials by designed barriers is originally controlled by the sorption ability of the mineral compositions. In this work, a naturally available mineral composite, a hydroxyl magnesium silicate (HMS) was investigated as potential natural inorganic sorbent for the retention of long-lived radionuclides ({sup 134}Cs, {sup 60}Co and {sup 152+154}Eu) from aqueous solutions. The factors affecting the sorption process, such as contact time and pH were evaluated. Furthermore X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), differential thermal and thermogravimetry analyses (DTA/TGA) measurements were examined in order to assess the physicochemical properties of the magnesium silicate mineral. Langmuir and Freundlich isotherms fitted the result s substantially better than the Flory-Huggins isotherm and the sorption was found to follow pseudo-first order kinetic model. The proposed mineral has been successfully applied for the sorption of {sup 134}Cs, {sup 60}Co and {sup 152+154}Eu radionuclides from real radioactive waste. The results indicated that about 97.4-99% of {sup 134}Cs, {sup 60}Co and {sup 152+154}Eu radionuclides were efficiently retained onto the HMS mineral. Based on the results obtained, it can be concluded that the HMS mineral is an economic and efficient retaining material for environmental hazardous migration and/or leakage of some radionuclides such as {sup 134}Cs, {sup 60}Co and {sup 152+154}Eu and trivalent actinide ({sup 241}Am, {sup 242m}Am and {sup 243}Am) ions. Therefore, this study could be used as a starting point to establish and consider that mineral as an engineered barrier around the disposal facilities at the nuclear activity centres.

Radionuclide migration experiments related to an underground nuclear test: II. modeling studies

International Nuclear Information System (INIS)

Tompson, A.; Carle, S.F.; Smith, D.K.; Hudson, G.B.; Bruton, C.J.

2001-01-01

Full text: The goal of this project is to improve our understanding of water and radionuclide migration in both saturated and unsaturated geologic media by coupling advanced simulation techniques, available characterization data, and radioanalytical measurements in the context of a remarkable field experiment. Between 1975 and 1991, groundwater was steadily pumped from a well adjacent to a 1965 underground test conducted in alluvium at the Nevada Test Site. The experiment was primarily conducted in order to elicit information on radionuclide migration through the saturated zone between the test and the well. The effluent was monitored. discharged to an unlined ditch, and allowed to infiltrate into the ground during flow towards a dry lake, about a kilometer away. The 16 years of pumping and infiltration created an unexpected second experiment in which the migration of the ditch effluent through the 200 meters of unsaturated media, back to the water table, could be studied. Pumping and effluent data are being utilized in conjunction with chemical measurements made in groundwater and a series of numerical models to better understand the movement of radionuclides in the system, both between the test and the well, and between the ditch and the water table. The release of radionuclides away from a testing area will be controlled by local groundwater flow rates, by their dissolution from solidified melt glass produced by the test, and by chemical sorption processes that retard their migration rates in chemically reactive geologic media. Only the more mobile and less reactive radionuclides (e.g.. tritium, 14 C, 36 Cl, 85 Kr, and 129 I) were measured in the well effluent. The movement of these radionuclides through the unsaturated media beneath the ditch will be affected additionally by the capillary nature of moisture movement under unsaturated conditions and by their interaction with and potential mass exchange with the gas (air) phase. Results of numerical simulations

The role of laboratory animals in studying bone cancer resulting from skeletally deposited radionuclides

International Nuclear Information System (INIS)

Boecker, B.B.; Miller, S.C.; Lloyd, R.D.; Taylor, G.N.; Griffith, W.C.; Guilmette, R.A.; Hahn, F.F.; Muggenburg, B.A.

1994-01-01

There is a continuing need to determine and understand the long-term health risks of internally deposited radionuclides in persons exposed medically or occupationally, or from radionuclides in the environment. A full understanding of these health risks, particularly for exposures involving low doses and dose rates, requires in-depth knowledge of both the dosimetry of a given exposure and the resulting long-term biological effects. Human data on 224 Ra and 226,228 Ra and their decay products are our primary sources of knowledge on the health risks of chronic alpha irradiation of the skeleton and serve as essential segments of our radiation protection practices for internally deposited radionuclides. However, we cannot obtain all of the needed information from these studies. This paper examines the role of laboratory animal studies in complementing and extending the knowledge of radiation-induced bone cancer obtained from studies of humans exposed to 224 Ra or 226,228 Ra

Radionuclide transfer from mother to embryo

International Nuclear Information System (INIS)

Toader, M.; Vasilache, R.A.; Scridon, R.; Toader, M.L.

1998-01-01

The transfer of radionuclides from mother to embryo is still a matter of high interest. Therefore, the relation was investigated between the amount of radionuclides in the embryo and the dietary intake of the mother, this for two scenarios: a recurrent intake of variable amounts of radionuclides, and a long-term intake of a relatively constant amount of radionuclides, the radionuclide being 137 Cs. In the first case, the amount of radionuclides present in the embryo increases with the age of the embryo and with the intake of the mother. In the second case, no correlation could be found between the age of the embryo and its radioactive content; only the correlation between the intake of the mother and the radionuclide content of the embryo remained. (A.K.)

Radionuclide diagnosis of emergency states

International Nuclear Information System (INIS)

Ishmukhametov, A.I.

1985-01-01

Solution of emergency state radionuclide diagnostics from the technical point of view is provided by the application of the mobile quick-operating equipment in combination with computers, by the use of radionuclides with acceptable for emergency medicine characteristics and by development of radionuclide investigation data propcessing express-method. Medical developments include the study of acute disease and injury radioisotope semiotics, different indication diagnostic value determining, comparison of the results, obtained during radionuclide investigation, with clinicolaboratory and instrumental data, separation of methodical complex series

Review of biokinetic and biological transport of transuranic radionuclides in the marine environment

International Nuclear Information System (INIS)

Beasley, T.M.; Cross, F.A.

1980-01-01

Present understanding of the uptake, retention, and loss of transuranic radionuclides by marine biota is limited. Laboratory experiments have demonstrated that for certain species assimilation of plutonium and americium from labeled food is an efficient process and that direct uptake from seawater is important in the bioaccumulation of all transuranic radionuclides studied to date. Organisms appear to play an important role in the vertical transport of these radioelements from the surface layers of the ocean to greater depths

Anthropogenic radionuclides in the environment

Energy Technology Data Exchange (ETDEWEB)

Hu, Q; Weng, J; Wang, J

2007-11-15

Studies of radionuclides in the environment have entered a new era with the renaissance of nuclear energy and associated fuel reprocessing, geological disposal of high-level nuclear wastes, and concerns about national security with respect to nuclear non-proliferation. This work presents an overview of anthropogenic radionuclide contamination in the environment, as well as the salient geochemical behavior of important radionuclides. We first discuss the following major anthropogenic sources and current development that contribute to the radionuclide contamination of the environment: (1) nuclear weapons program; (2) nuclear weapons testing; (3) nuclear power plants; (4) commercial fuel reprocessing; (5) geological repository of high-level nuclear wastes, and (6) nuclear accidents. Then, we summarize the geochemical behavior for radionuclides {sup 99}Tc, {sup 129}I, and {sup 237}Np, because of their complex geochemical behavior, long half-lives, and presumably high mobility in the environment. Biogeochemical cycling and environment risk assessment must take into account speciation of these redox-sensitive radionuclides.

Radionuclide daughter inventory generator code: DIG

International Nuclear Information System (INIS)

Fields, D.E.; Sharp, R.D.

1985-09-01

The Daughter Inventory Generator (DIG) code accepts a tabulation of radionuclide initially present in a waste stream, specified as amounts present either by mass or by activity, and produces a tabulation of radionuclides present after a user-specified elapsed time. This resultant radionuclide inventory characterizes wastes that have undergone daughter ingrowth during subsequent processes, such as leaching and transport, and includes daughter radionuclides that should be considered in these subsequent processes or for inclusion in a pollutant source term. Output of the DIG code also summarizes radionuclide decay constants. The DIG code was developed specifically to assist the user of the PRESTO-II methodology and code in preparing data sets and accounting for possible daughter ingrowth in wastes buried in shallow-land disposal areas. The DIG code is also useful in preparing data sets for the PRESTO-EPA code. Daughter ingrowth in buried radionuclides and in radionuclides that have been leached from the wastes and are undergoing hydrologic transport are considered, and the quantities of daughter radionuclide are calculated. Radionuclide decay constants generated by DIG and included in the DIG output are required in the PRESTO-II code input data set. The DIG accesses some subroutines written for use with the CRRIS system and accesses files containing radionuclide data compiled by D.C. Kocher. 11 refs

Sellafield waste radionuclides in Irish sea intertidal and salt marsh sediments.

Science.gov (United States)

Mackenzie, A B; Scott, R D

1993-09-01

Low level liquid radioactive waste discharges from the Sellafield nuclear fuel reprocessing plant in north west England had generated environmental inventories of about 3 × 10(16) Bq of(137)Cs, 6.8 × 10(14) Bq of(239,240)Pu and 8.9 × 10(14) Bq of(241)Am by 1990. Most of the(239,240)Pu and(241)Am and about 10% of the(137)Cs has been retained in a deposit of fine marine sediment close to the discharge point. The quantities of radionuclides discharged annually from Sellafield decreased by two orders of magnitude from the mid-1970s to 1990 but estimated critical group internal and external exposure decreased by less than one order of magnitude over this period. This indicates that during the period of reduced discharges, radionuclides already in the environment from previous releases continued to contribute to the critical group exposure and highlights the need to understand processes controlling the environmental distribution of the radionuclides.Redistribution of the contaminated marine sediment is potentially of major significance in this context, in particular if it results in transport of radionuclides to intertidal areas, where contact with the human population is relatively likely.A review is presented of published work relating to Sellafield waste radionuclides in Irish Sea sediments. Data on temporal and spatial trends in radionuclide concentrations and activity ratios are collated from a number of sources to show that the dominant mechanism of radionuclide supply to intertidal areas is by redistribution of the contaminated marine sediment. The implications of this mechanism of supply for trends in critical group radiation exposure are considered.

Interaction of radionuclides in severe accident conditions

International Nuclear Information System (INIS)

Nagrale, Dhanesh B.; Bera, Subrata; Deo, Anuj Kumar; Paul, U.K.; Prasad, M.; Gaikwad, A.J.

2015-01-01

Nuclear power plants are designed with inherent engineering safety systems and associated operational procedures that provide an in-depth defence against accidents. Radionuclides such as Iodine, Cesium, Tellurium, Barium, Strontium, Rubidium, Molybdenum and many others may get released during a severe accident. Among these, Iodine, one of the fission products, behaviour is significant for the analysis of severe accident consequences because iodine is a chemically more active to the potential components released to the environment. During severe accident, Iodine is released and transported in aqueous, organic and inorganic forms. Iodine release from fuel, iodine transport in primary coolant system, containment, and reaction with control rods are some of the important phases in a severe accident scenario. The behaviour of iodine is governed by aerosol physics, depletion mechanisms gravitational settling, diffusiophoresis and thermophoresis. The presence of gaseous organic compounds and oxidizing compounds on iodine, reactions of aerosol iodine with boron and formation of cesium iodide which results in more volatile iodine release in containment play significant roles. Water radiolysis products due to presence of dissolved impurities, chloride ions, organic impurities should be considered while calculating iodine release. Containment filtered venting system (CFVS) consists of venturi scrubber and a scrubber tank which is dosed with NaOH and NaS_2O_3 in water where iodine will react with the chemicals and convert into NaI and Na_2SO_4. This paper elaborates the issues with respect to interaction of radionuclides and its consideration in modeling of severe accident. (author)

Critical review: Radionuclide transport, sediment transport, and water quality mathematical modeling; and radionuclide adsorption/desorption mechanisms

Energy Technology Data Exchange (ETDEWEB)

Onishi, Y.; Serne, R.J.; Arnold, E.M.; Cowan, C.E.; Thompson, F.L. [Pacific Northwest Lab., Richland, WA (United States)

1981-01-01

This report describes the results of a detailed literature review of radionuclide transport models applicable to rivers, estuaries, coastal waters, the Great Lakes, and impoundments. Some representatives sediment transport and water quality models were also reviewed to evaluate if they can be readily adapted to radionuclide transport modeling. The review showed that most available transport models were developed for dissolved radionuclide in rivers. These models include the mechanisms of advection, dispersion, and radionuclide decay. Since the models do not include sediment and radionuclide interactions, they are best suited for simulating short-term radionuclide migration where: (1) radionuclides have small distribution coefficients; (2) sediment concentrations in receiving water bodies are very low. Only 5 of the reviewed models include full sediment and radionuclide interactions: CHMSED developed by Fields; FETRA SERATRA, and TODAM developed by Onishi et al, and a model developed by Shull and Gloyna. The 5 models are applicable to cases where: (1) the distribution coefficient is large; (2) sediment concentrations are high; or (3) long-term migration and accumulation are under consideration. The report also discusses radionuclide absorption/desorption distribution ratios and addresses adsorption/desorption mechanisms and their controlling processes for 25 elements under surface water conditions. These elements are: Am, Sb, C, Ce, Cm, Co, Cr, Cs, Eu, I, Fe, Mn, Np, P, Pu, Pm, Ra, Ru, Sr, Tc, Th, {sup 3}H, U, Zn and Zr.

Development of a mechanistic model for release of radionuclides from spent fuel in brines: Salt Repository Project

International Nuclear Information System (INIS)

Reimus, P.W.; Windisch, C.F.

1988-03-01

At present there are no comprehensive mechanistic models describing the release of radionuclides from spent fuel in brine environments. This report provides a comprehensive review of the various factors that can affect radionuclide release from spent fuel, suggests a modeling approach, and discusses proposed experiments for obtaining a better mechanistic understanding of the radionuclide release processes. Factors affecting radionuclide release include the amount, location, and disposition of radionuclides in the fuel and environmental factors such as redox potential, pH, the presence of complexing anions, temperature, and radiolysis. It is concluded that a model describing the release of radionuclides from spent fuel should contain separate terms for release from the gap, grain boundaries, and grains of the fuel. Possible functional forms for these terms are discussed in the report. Experiments for assessing their validity and obtaining key model parameters are proposed. 71 refs., 4 figs., 6 tabs

Deposition and interception of radionuclides. Current knowledge and future requirements

International Nuclear Information System (INIS)

1998-12-01

Following an accidental or routine release of radionuclides into the environment, a good knowledge of deposition processes is necessary in order to accurately predict the radiation dose to members of the public. In order to understand the environmental impact of released radionuclides and their transfer through the environment, including the food chain to man, there have been numerous studies on deposition of radionuclides to a range of surfaces such as bare soil, crops, forests, water bodies and urban surfaces. The RADREM committee provides a forum for liaison on UK research and monitoring in the areas of radioactive substances and radioactive waste management. RADREM has set up four sub-committees to cover issues related to radioactivity in the atmospheric, terrestrial and aquatic environments as well as those related radioactive waste management. One of the sub-committee tasks is to organise seminars and workshops on specific topics of interest. The first of these was the workshop on 'Deposition and Interception of Radionuclides: Current knowledge and future requirements' organised last year by the Ministry of Agriculture, Fisheries and Food (MAFF), acting as secretariat for the Terrestrial Environment Sub-Committee (TESC) of RADREM. The intent of this workshop was to provide an opportunity to exchange information on deposition-related aspects between representatives from various interested parties including government, regulatory bodies, industry and research organisations. Through presentations and discussions, this workshop addressed current developments in the areas of deposition and interception of radionuclides by various surfaces and served to identify areas which need further research. Papers were presented on various aspects of deposition and interception of radionuclides including deposition into grass, fruits and other crops as well as deposition into urban areas and forests

Sediments as indicators of artificial radionuclide distribution west of La Hague

International Nuclear Information System (INIS)

Guegueniat, P.; Auffret, J.P.; Ballada, J.

1981-01-01

Four-year investigations of the coastal surface sediments and associated radionuclides in the English Channel show complex distribution patterns around La Hague. Plutonium ratios in the particulate fraction confirm the general understanding gathered from long-term gamma studies - mainly that accumulation of La Hague generated radionuclides is in the Bay of Mont-Saint-Michel and along the Normandy-Brittany Coast. The oil from the Amoco Cadiz accident caused a significant increase in coastal sediment activity of 144 Ce. Experimental studies with plutonium and hydrocarbons indicate that plutonium is more difficult to desorb than 144 Ce. (author)

History of medical radionuclide production.

Science.gov (United States)

Ice, R D

1995-11-01

Radionuclide production for medical use originally was incidental to isotope discoveries by physicists and chemists. Once the available radionuclides were identified they were evaluated for potential medical use. Hevesy first used 32P in 1935 to study phosphorous metabolism in rats. Since that time, the development of cyclotrons, linear accelerators, and nuclear reactors have produced hundreds of radionuclides for potential medical use. The history of medical radionuclide production represents an evolutionary, interdisciplinary development of applied nuclear technology. Today the technology is represented by a mature industry and provides medical benefits to millions of patients annually.

Electromigration of carrier-free radionuclides. 13

International Nuclear Information System (INIS)

Roesch, F.; Reimann, T.; Buglanov, G.V.; Milanov, M.; Khalkin, V.A.; Dreyer, R.

1988-01-01

Using a special type of on line electromigration measurements of γ-emitting radionuclides in homogeneous aqueous electrolytes free of supporting materials the electromigration behaviour of the carrier-free 241 Am-Am(III) in inert electrolytes, μ = 0.1 (ClO 4 - ), T = 298.1(1) K, was studied. Basing on experimental dependencies of the overall ion mobilities of 241 Am-Am(III) on pH between pH 5.5 and 12.9 the stoichiometric hydrolysis constants pβ 3 = 28.8(9) and pK 1 = 6.9(2) were obtained. For K 4 a limitation of pK 4 > 13.9(3) was possible, because no formation of anionic hydrolysis products in solutions pH 241 Am-Am(III) degrees in the range pH 5.5 - 3 from +6.85(15) up to +5.50(15) · 10 -4 cm 2 s -1 V -1 . Dependencies of this effect on overall ionic strength, inert electrolyte anion, and temperature of the electrolytes were studied in detail both in acidic and neutral solutions. (author)

Transfer of fallout radionuclides derived from Fukushima NPP accident: 1 year study on transfer of radionuclides through hydrological processes

Science.gov (United States)

Onda, Yuichi; Kato, Hiroaki; Patin, Jeremy; Yoshimura, Kazuya; Tsujimura, Maki; Wakahara, Taeko; Fukushima, Takehiko

2013-04-01

Previous experiences such as Chernobyl Nuclear Power Plant accident have confirmed that fallout radionuclides on the ground surface migrate through natural environment including soils and rivers. Therefore, in order to estimate future changes in radionuclide deposition, migration process of radionuclides in forests, soils, ground water, rivers should be monitored. However, such comprehensive studies on migration through forests, soils, ground water and rivers have not been conducted so far. Here, we present the following comprehensive investigation was conducted to confirm migration of radionuclides through natural environment including soils and rivers. 1)Study on depth distribution of radiocaesium in soils within forests, fields, and grassland 2)Confirmation of radionuclide distribution and investigation on migration in forests 3)Study on radionuclide migration due to soil erosion under different land use 4)Measurement of radionuclides entrained from natural environment including forests and soils 5)Investigation on radionuclide migration through soil water, ground water, stream water, spring water under different land use 6)Study on paddy-to-river transfer of radionuclides through suspended sediments 7)Study on river-to-ocean transfer of radionuclides via suspended sediments 8)Confirmation of radionuclide deposition in ponds and reservoirs

The physiological basis and application of renal radionuclide studies

International Nuclear Information System (INIS)

Britton, K.E.

1983-01-01

A knowledge of the basic physiology of the kidney is essential for an understanding of the application of radionuclide studies in clinical practice. A knowledge of the physiology of the kidney allows one to develop physiological models that are isomorphic and then apply the appropriate type of data analysis in relationship to these models. In this way mistakes in the type of analysis can be avoided and a strong basis for the interpretation of renal radionuclide studies in health and disease is thereby provided. Methods for measuring total renal function, the contribution of each kidney to total renal function, the presence or absence of obstructive nephropathy and the determination of the relative flows to the cortical and juxtamedullary nephrons are given as examples of this approach. (author)

The rocky flats controversy on radionuclide soil action levels

International Nuclear Information System (INIS)

Earle, T.C.

2004-01-01

An account of the Rocky Flats radionuclide soil action level controversy is presented as: a case study for the purpose of understanding the nature and value of stakeholder involvement in the management of radiological hazards. The report consists of three main sections. The first section outlines the Rocky Flats story, including the Cold War era, which was characterised by secrecy and distrust, the post-Cold War era, in which trust and co-operation between risk managers and the public began to develop. This contrast between these two historical periods provides the context necessary to understand the radionuclide soil action level controversy, the main events of which are described in the second section. In the final section, the Rocky Flats case is briefly discussed within the framework of a general model of stakeholder involvement and the lessons learned from the case are identified: (1) without a basis in shared values, collaborative public involvement in the management of radiological hazards is not possible; (2) given a basis in shared values, collaborative public involvement can lead to improved solutions to the management of radiological hazards; and (3) risk managers should therefore seek to understand the values of public stakeholders and to identify ways, through stakeholder involvement, that those values can be incorporated in management practice. (author)

XAS Investigation of bio-relevant cobalt complexes in aqueous media

International Nuclear Information System (INIS)

Bresson, C.; Lamouroux, C.; Esnouf, S.; Solari, P.L.; Den Auwer, C.

2006-01-01

Cobalt is an essential element of biological cycles involved in numerous metallo-biomolecules, but it becomes a toxic element at high concentration or a radio-toxic element because of its use in the nuclear industry. 'Molecular speciation' in biological media is an essential prerequisite to evaluate its chemical behaviour as well as its toxic or beneficial effects. In this scheme, we have focused on the coordination properties of the thiol-containing amino acid cysteine (Cys) and the pseudo-peptide N-(2-mercapto-propionyl) glycine (MPG) towards the Co 2+ cation in aqueous media. XAS at the Co K edge and traditional spectroscopic techniques have been coupled in order to structurally characterize the cobalt coordination sphere. Oxidation states and geometries of the bis- and tris-cysteinato Co(III) complexes are in agreement with the literature data. In addition, bond lengths between the metallic centre and the donor atoms have been determined. The structure of a new dimeric N-(2-mercapto-propionyl) glycinato Co(II) complex in solution is also reported. The coordination of MPG to Co(II) through the thiolate and carboxylate functions is ascertained. This work provides fundamental structural information about bio-relevant complexes of cobalt, which will contribute to our understanding of the chemical behaviour and the biological role of this radionuclide. (authors)

Transuranic radionuclides in the environment surrounding radioactive waste diposal sites, a bibliography

International Nuclear Information System (INIS)

Stoker, A.C.; Noshkin, V.E.; Wong, K.M.; Brunk, J.L.; Conrado, C.L.; Jones, H.E.; Kehl, S.; Stuart, M.L.; Wasley, L.M.; Bradsher, R.V.

1994-08-01

The purpose of this project was to compile a bibliography of references containing environmental transuranic radionuclide data. Our intent was to identify those parameters affecting transuranic radionuclide transport that may be generic and those that may be dependent on chemical form and/or environmental conditions (i.e. site specific). An understanding of the unique characteristics and similarities between source terms and environmental conditions relative to transuranic radionuclide transport and cycling will provide the ability to assess and predict the long term impact on man and the environment. An additional goal of our literature review, was to extract the ranges of environmental transuranic radionuclide data from the identified references for inclusion in a data base. Related to source term, these ranges of data can be used to calculate the dose to man from the radionuclides, and to perform uncertainty analyses on these dose assessments. In an attempt to gather relevant information about the transuranic radionuclides in a variety of environments, we conducted an extensive literature search. In our literature search we identified over 5700 potential written sources of information for review. In addition, we have identified many references which were not found through the literature searches, but which were known to contain useful data. A total of approximately 2600 documents were determined to contain information which would be useful for an in depth study of radionuclides in different environments. The journal articles, books, reports and other documents were reviewed to obtain the source term of the radionuclides studied. Most references containing laboratory study data were not included in our databases. Although these may contain valuable data, we were trying to compile references with information on the behavior of the transuranics in the specific environment being studied

Adsorption of some Hazardous Radionuclides from their Aqueous Waste Solutions using Synthetic Silico(IV)titanate

International Nuclear Information System (INIS)

EI-Naggar, I.M.; Mowafy, E.A.; Abdel-Galil, E.A.; Ghonaim, A.Kh.

2008-01-01

Silico(IV)titanate as a cation exchanger has been obtained in a semi-crystalline form. This inorganic ion exchanger has high chemical stability. The capacities of this material for selected radionuclides such as Cs + , Na + , Co 2+ and Eu 3+ were investigated, and the selectivity was found in the order; Cs + > Eu 3+ > Co 2+ > Na + , Exchange isotherms for H + /Cs + , H + /Co 2+ and H + /Eu 3+ were determined at 25, 45 and 65±1 degree C. These isotherms showed that Cs + , Co 2+ and Eu 3+ are chemically adsorbed. Moreover, the values of thermodynamic parameters were determined and the overall adsorption processes were found spontaneous and endothermic

Modelling and experimental studies on the transfer of radionuclides to fruit

International Nuclear Information System (INIS)

Carini, F.; Atkinson, C.J.; Collins, C.; Coughtrey, P.J.; Eged, K.; Fulker, M.; Green, N.; Kinnersley, R.; Linkov, I.; Mitchell, N.G.; Mourlon, C.; Ould-Dada, Z.; Quinault, J.M.; Robles, B.; Stewart, A.; Sweeck, L.; Venter, A.

2005-01-01

Although fruit is an important component of the diet, the extent to which it contributes to radiological exposure remains unclear, partially as a consequence of uncertainties in models and data used to assess transfer of radionuclides in the food chain. A Fruits Working Group operated as part of the IAEA BIOMASS (BIOsphere Modelling and ASSessment) programme from 1997 to 2000, with the aim of improving the robustness of the models that are used for radiological assessment. The Group completed a number of modelling and experimental activities including: (i) a review of experimental, field and modelling information on the transfer of radionuclides to fruit; (ii) discussion of recently completed or ongoing experimental studies; (iii) development of a database on the transfer of radionuclides to fruit; (iv) development of a conceptual model for fruit and (v) two model intercomparison studies and a model validation study. The Group achieved significant advances in understanding the processes involved in transfer of radionuclides to fruit. The work demonstrated that further experimental and modelling studies are required to ensure that the current generation of models can be applied to a wide range of scenarios

Strategy for a consistent selection of radionuclide migration parameters for the Belgian safety and feasibility case-1

International Nuclear Information System (INIS)

Bruggeman, C.; Maes, N.; Salah, S.; Brassinnes, S.; Van Geet, M.

2010-01-01

Document available in extended abstract form only. The purpose of this presentation is to describe the strategy for the selection of retention and migration parameters for safety-relevant nuclides that was developed in the framework of the Belgian Safety and Feasibility Case SFC-1. A geochemical database containing state-of-the-art retention and migration parameters of all safety-relevant radionuclides, is ideally based on a thermodynamic understanding and an ability to accurately describe the geochemical and transport behaviour of all these radionuclides under the geochemical conditions that are considered for a reference host formation. In Belgium, this reference formation is Boom Clay. The parameters will be used in Performance Assessment (PA) calculations, and therefore must also be adapted to PA models. Since these models currently use only a four parameters for every radionuclide, the whole geochemical and transport behaviour must be comprised to a very limited parameter set that describe on the one hand chemical retention within the Boom Clay formation, and on the other hand transport through the Boom Clay formation. Chemical retention considers two concepts: 1) a concentration limit (S), which represents the mobile concentration of a nuclide present in the aqueous phase under undisturbed far field Boom Clay conditions; 2) a retardation (R/Kd) factor, which represents the uptake of a mobile nuclide by the inorganic and organic phases present in the Boom Clay formation. For mobility/migration two additional concepts are introduced: 3) the diffusion accessible porosity (η), which is the total physical space available for transport of a nuclide. The maximum value of η is limited by the water content of the formation; 4) the pore diffusion coefficient (Dp), which represents the transport velocity of a nuclide in a diffusion-dominated system. Within the framework of SFC-1, primary focus is laid on the compilation of parameter ranges, instead of individual &apos

Conditions and processes affecting radionuclide transport

Science.gov (United States)

Simmons, Ardyth M.; Neymark, Leonid A.

2012-01-01

Characteristics of host rocks, secondary minerals, and fluids would affect the transport of radionuclides from a previously proposed repository at Yucca Mountain, Nevada. Minerals in the Yucca Mountain tuffs that are important for retarding radionuclides include clinoptilolite and mordenite (zeolites), clay minerals, and iron and manganese oxides and hydroxides. Water compositions along flow paths beneath Yucca Mountain are controlled by dissolution reactions, silica and calcite precipitation, and ion-exchange reactions. Radionuclide concentrations along flow paths from a repository could be limited by (1) low waste-form dissolution rates, (2) low radionuclide solubility, and (3) radionuclide sorption onto geological media.

Verification and improvement of a predictive model for radionuclide migration

International Nuclear Information System (INIS)

Miller, C.W.; Benson, L.V.; Carnahan, C.L.

1982-01-01

Prediction of the rates of migration of contaminant chemical species in groundwater flowing through toxic waste repositories is essential to the assessment of a repository's capability of meeting standards for release rates. A large number of chemical transport models, of varying degrees of complexity, have been devised for the purpose of providing this predictive capability. In general, the transport of dissolved chemical species through a water-saturated porous medium is influenced by convection, diffusion/dispersion, sorption, formation of complexes in the aqueous phase, and chemical precipitation. The reliability of predictions made with the models which omit certain of these processes is difficult to assess. A numerical model, CHEMTRN, has been developed to determine which chemical processes govern radionuclide migration. CHEMTRN builds on a model called MCCTM developed previously by Lichtner and Benson

Dynamics of radionuclides in forest environments

International Nuclear Information System (INIS)

Belli, M.; Tikhomirov, F.A.; Kliashtorin, A.; Shcheglov, A.; Rafferty, B.; Shaw, G.; Wirth, E.; Kammerer, L.; Ruehm, W.; Steiner, M.; Delvaux, B.; Maes, E.; Kruyts, N.; Bunzl, K.; Dvornik, A.M.; Kuchma, N.

1996-01-01

In the CIS countries, during the Chernobyl accident, more than 30000 km 2 of forested areas received a 137 Cs deposition higher than 37 kBq m -2 and about 1000 km 2 a deposition of radiocesium higher than 1.5 MBq m -2 . Before the accident only few data were available on the behaviour of radionuclides in forests and during last eight years, the understanding of the fate of radionuclides in these ecosystems has been improved significantly. This paper reports the results achieved in the frame of 1991-1996 EU/CIS collaborative project on the consequences of the Chernobyl accident. The ECP-5 project deals with the impact of radioactive contamination on natural and semi-natural environment. The investigations were carried out in different forest ecosystems, located in the near field (within the 30-km zone around the Chernobyl nuclear power plant) as well as in the far field in the CIS and in the western Europe countries. The results achieved have been used to develop a simplified model representation of the behaviour of radiocesium within forest ecosystems

Measurement of radionuclides using ion chromatography and flow-cell scintillation counting with pulse shape discrimination

International Nuclear Information System (INIS)

DeVol, T.A.; Fjeld, R.A.

1995-01-01

A project has been initiated at Clemson Univ. to develop a HPLC/flow- cell system for analysis of non-gamma emitting radionuclides in environmental samples; an important component is development of a low background flow-cell detector that counts alpha and beta particles separately through pulse shape discrimination. Objective of the work presented here is to provide preliminary results of an evaluation of the following scintillators: CaF 2 :Eu, scintillating glass, and BaF 2 . Slightly acidic aqueous solutions of the alpha emitter 233 U and the beta emitter 45 Ca were used. Detection efficiencies and minimum detectable activities were determined

Radionuclides in air, water, and biota

International Nuclear Information System (INIS)

Seymour, A.H.; Nelson, V.A.

1977-01-01

Air, water, and biological samples collected before and after the 1965, 1969, and 1971 underground nuclear detonations at Amchitka Island were analyzed for natural and fallout radionuclides by gamma spectrometry. Selected samples were also analyzed for tritium, 55 Fe, and 90 Sr. The objectives were to search for and identify radionuclides of Amchitka origin in the samples and to contribute to the general knowledge of the distribution of radionuclides in the environment. The studies showed that there has been no escape of radionuclides from the underground sites of the three nuclear detonations at Amchitka Island except for trace quantities of radionuclides, principally tritium, in water and soil gas samples from the immediate vicinity of the surface ground zero for the 1965 event. Two naturally occurring radionuclides, 40 K and 7 Be, were the most abundant radionuclides in the samples, usually by a factor of 10 or more, except for 137 Cs in lichen samples. All levels were well below applicable Radiation Protction Guides, often being near the statistical limit of detection

Phytoremediation of radionuclides: an emerging alternative

International Nuclear Information System (INIS)

Singh, Shraddha

2013-01-01

Proliferation of nuclear power industry, nuclear weapon testing, dismantling of existing nuclear weapons and occasional accidents have contributed to an enhancement in the level of radionuclides in the environment. The radionuclides due to their long half life and transfer through the food chain effect adversely to normal biological systems. Hence, it is essential to effectively remove the radionuclides from contaminated soils and solutions. Phytoremediation - the use of plants for remediation of toxic metals and radionuclides has been recognized as an aesthetically pleasing, low cost and environment friendly in situ method. Phytoremediation is an umbrella term which covers several plant based approaches. Plants have shown the potential of remediation of these radionuclides from spiked solutions, low level nuclear waste and soil. Various aspects of phytoremediation as well as potential of various plants for remediation of radionuclides will be discussed here. (author)

Diffusion and Leaching Behavior of Radionuclides in Category 3 Waste Encasement Concrete and Soil Fill Material – Summary Report

Energy Technology Data Exchange (ETDEWEB)

Mattigod, Shas V.; Wellman, Dawn M.; Bovaird, Chase C.; Parker, Kent E.; Clayton, Libby N.; Powers, Laura; Recknagle, Kurtis P.; Wood, Marcus I.

2011-08-31

diffusion of radionuclides may be affected by the formation of structural cracks in concrete, the carbonation of the buried waste form, and any potential effect of metallic iron (in the form of rebars) on the mobility of radionuclides. The radionuclides iodine-129 ({sup 129}I), technetium-99 ({sup 99}Tc), and uranium-238 ({sup 238}U) are identified as long-term dose contributors in Category 3 waste (Mann et al. 2001; Wood et al. 1995). Because of their anionic nature in aqueous solutions, {sup 129}I, {sup 99}Tc, and carbonate-complexed {sup 238}U may readily leach into the subsurface environment (Serne et al. 1989, 1992a, b, 1993, and 1995). The leachability and/or diffusion of radionuclide species must be measured to assess the long-term performance of waste grouts when contacted with vadose-zone pore water or groundwater. Although significant research has been conducted on the design and performance of cementitious waste forms, the current protocol conducted to assess radionuclide stability within these waste forms has been limited to the Toxicity Characteristic Leaching Procedure, Method 1311 Federal Registry (EPA 1992) and ANSI/ANS-16.1 leach test (ANSI 1986). These tests evaluate the performance under water-saturated conditions and do not evaluate the performance of cementitious waste forms within the context of waste repositories which are located within water-deficient vadose zones. Moreover, these tests assess only the diffusion of radionuclides from concrete waste forms and neglect evaluating the mechanisms of retention, stability of the waste form, and formation of secondary phases during weathering, which may serve as long-term secondary hosts for immobilization of radionuclides. The results of recent investigations conducted under arid and semi-arid conditions (Al-Khayat et al. 2002; Garrabrants et al. 2002; Garrabrants and Kosson 2003; Garrabrants et al. 2004; Gervais et al. 2004; Sanchez et al. 2002; Sanchez et al. 2003) provide valuable information suggesting

A comparison of measured radionuclide release rates from Three Mile Island Unit-2 core debris for different oxygen chemical potentials

International Nuclear Information System (INIS)

Baston, V.F.; Hofstetter, K.J.; Ryan, R.F.

1987-01-01

Chemical and radiochemical analyses of reactor coolant samples taken during defueling of the Three Mile Island Unit-2 (TMI-2) reactor provide relevant data to assist in understanding the solution chemistry of the radionuclides retained within the TMI-2 reactor coolant system. Hydrogen peroxide was added to various plant systems to provide disinfection for microbial contamination and has provided the opportunity to observe radionuclide release under different oxygen chemical potentials. A comparison of the radionuclide release rates with and without hydrogen peroxide has been made for these separate but related cases, i.e., the fuel transfer canal and connecting spent-fuel pool A with the TMI-2 reactor plenum in the fuel transfer canal, core debris grab sample laboratory experiments, and the reactor vessel fluid and associated core debris. Correlation and comparison of these data indicate a physical parameter dependence (surface-to-volume ratio) affecting all radionuclide release; however, selected radionuclides also demonstrate a chemical dependence release under the different oxygen chemical potentials. Chemical and radiochemical analyses of reactor coolant samples taken during defueling of the Three Mile Island Unit-2 (TMI-2) reactor provide relevant data to assist in understanding the solution chemistry of the radionuclides retained within the TMI-2 reactor coolant system

CASCADER: An m-chain gas-phase radionuclide transport and fate model

International Nuclear Information System (INIS)

Cawlfield, D.E.; Been, K.B.; Emer, D.F.; Lindstrom, F.T.; Shott, G.J.

1993-06-01

Chemicals and radionuclides move either in the gas-phase, liquid-phase, or both phases in soils. They may be acted upon by either biological or abiotic processes through advection and/or diffusion. Furthermore, parent and daughter radionuclides may decay as they are transported in the soil. This is volume two to the CASCADER series, titled CASCADR8. It embodies the concepts presented in volume one of this series. To properly understand how the CASCADR8 model works, the reader should read volume one first. This volume presents the input and output file structure for CASCADR8, and a set of realistic scenarios for buried sources of radon gas

Radionuclides in food

International Nuclear Information System (INIS)

Fernandez Gomez, Isis Maria

2008-01-01

The sources of the presence of radionuclides in food are presented: natural radiation and artificial radiation. The transfer of radionuclides through food chains, intakes of radionuclides to the body with its partners effective doses and typical consumption of basic foods of a rural adult population are exposed as main topics. Also the radiation doses from natural sources and exposure to man by ingestion of contaminated food with radionuclides of artificial origin are shown. The contribution of the food ingestion to the man exposure depends on: characteristics of radionuclide, natural conditions, farming practices and eating habits of the population. The principal international organizations in charge of setting guide levels for radionuclides in food are mentioned: standards, rules and the monitoring. It establishes that a guide is necessary for the food monitoring; the alone CODEX ALIMENTARIUS is applicable to emergency situations and the generic action levels proposed by the CODEX not satisfy all needs (no guiding international levels for planned or existing situations such as NORM). There are handled mainly socio-economic and political aspects. Among the actions to be taken are: to assure a public comprehensive information over the risk evaluation in food; to reinforce the collaboration among the different international organizations (WHO, IAEA, ICRP, EC) in relation with the food of set; to give follow-up to the control of the drinkable water and NORM's presence in the food. In addition, it is possible to create the necessary mechanisms to reduce the number of irrelevant measures and bureaucratic useless steps (certificates); to promote the exchange between the different institutions involved in the topic of the food, with relation to the acquired experiences and learned lessons. Likewise, it might examine the possibility of a multidisciplinary approximation (radioactive and not radioactive pollutants); to elaborate a technical guide to assure the

Initial Radionuclide Inventories

Energy Technology Data Exchange (ETDEWEB)

H. Miller

2004-09-19

The purpose of this analysis is to provide an initial radionuclide inventory (in grams per waste package) and associated uncertainty distributions for use in the Total System Performance Assessment for the License Application (TSPA-LA) in support of the license application for the repository at Yucca Mountain, Nevada. This document is intended for use in postclosure analysis only. Bounding waste stream information and data were collected that capture probable limits. For commercially generated waste, this analysis considers alternative waste stream projections to bound the characteristics of wastes likely to be encountered using arrival scenarios that potentially impact the commercial spent nuclear fuel (CSNF) waste stream. For TSPA-LA, this radionuclide inventory analysis considers U.S. Department of Energy (DOE) high-level radioactive waste (DHLW) glass and two types of spent nuclear fuel (SNF): CSNF and DOE-owned (DSNF). These wastes are placed in two groups of waste packages: the CSNF waste package and the codisposal waste package (CDSP), which are designated to contain DHLW glass and DSNF, or DHLW glass only. The radionuclide inventory for naval SNF is provided separately in the classified ''Naval Nuclear Propulsion Program Technical Support Document'' for the License Application. As noted previously, the radionuclide inventory data presented here is intended only for TSPA-LA postclosure calculations. It is not applicable to preclosure safety calculations. Safe storage, transportation, and ultimate disposal of these wastes require safety analyses to support the design and licensing of repository equipment and facilities. These analyses will require radionuclide inventories to represent the radioactive source term that must be accommodated during handling, storage and disposition of these wastes. This analysis uses the best available information to identify the radionuclide inventory that is expected at the last year of last emplacement

Optimization of strontium adsorption from aqueous solution using (mn-Zr) oxide-pan composite spheres

International Nuclear Information System (INIS)

Inan, S.; Altas, Y.

2009-01-01

The processes based on adsorption and ion exchange have a great role for the pre-concentration and separation of toxic, long lived radionuclides from liquid waste. In Nuclear waste management, the removal of long lived, radiotoxic isotopes from radioactive waste such as strontium reduces the storage problems and facilitates the disposal of the waste. Depending on the waste type, a variety of adsorbents and/or ion exchangers are used. Due to the amorphous structure of hydrous oxides and their mixtures, they don't have reproducible properties. Besides, obtained powders are very fine particles and they can cause operational problems such as pressure drop and filtration. Therefore they are not suitable for column applications. These reasons have recently expedited the study on the preparation of organic-inorganic composite adsorbent beads for industrial applications. PAN, as a stable and porous support for fine particles, provides the utilization of ion exchangers in large scale column applications. The utilization of PAN as a support material with many inorganic ion exchangers was firstly achieved by Sebesta in the beginning of 1990's. Later on, PAN based composite ion exchangers were prepared and used for the removal of radionuclides and heavy metal ions from aqueous solution and waste waters. In this study, spherical (Mn-Zr)oxide-PAN composite were prepared for separation of strontium from aqueous solution in a wide pH range. Sr 2 + adsorption of composite adsorbent was optimized by using experimental design 'Central Composite Design' model.

Determination of alpha radionuclides in fish

International Nuclear Information System (INIS)

Pernicka, L.; Matel, L.; Rosskopfova, O.

2001-01-01

In atmospheric water, external water and undercurrent the occurrence of radionuclides is usual. It is an important factor of quality of the environment. Plants ingest radionuclides from water and with they everyone. And it arises radioactivity infest food-chain. Radiotoxicity of this radionuclides is very deer sometimes. The sensitive radiochemical procedures for their determination are necessarily important. The poster presents the combined procedure used at our laboratory for determination of alpha radionuclides in biological samples. (authors)

The glass block site radionuclide migration study

International Nuclear Information System (INIS)

Killey, R.W.D.; Champ, D.R.

1990-01-01

In 1960 25 nepheline syenite glass blocks containing 14 TBq of mixed fission products in 50 kg of glass were placed below the water table in a shallow sand aquifer at Chalk River Laboratories. Experimental studies undertaken at the site since 1960 have included detailed mapping of the plume of 90 Sr in 1963, 1966 and 1971. Mathematical modeling studies have employed the radiostrontium plume data in determining the split between ion exchange and chemisorption of 90 Sr, and in obtaining reaction rate data for chemisorption. The distribution of 137 Cs on downgradient soils was mapped in 1963 and 1979. An extended plume of low-level 137 Cs contamination observed in the 1979 study prompted an investigation of the role of particulate materials in radionuclide transport. IN 1983, large volume groundwater sampling and separation of cationic, anionic, and neutral dissolved species, as well as particulates, detected anionic and cationic dissolved europium isotopes (154 and 155), and again encountered particulate 137 Cs. A variety of investigations of cesium and strontium sorption have provided a data base on sediment mineralogy, particle surface features, and information on sorption sites and processes. The year 1990 saw the inauguration of a three-year program to update investigations of radionuclide release, transport, and sorption at the glass block site. The first stage of the program has been a detailed definition and simulation of the hydrogeologic setting. Plume mapping and aqueous speciation studies are in progress. This paper summarizes past investigations, reviews the status of the current program, and discusses components of future studies, including investigations of sediment sorption mechanisms. (Author) (17 refs., 8 figs.)

Impurity radionuclide analysis for the radiopharmaceutical Na[123I] using gamma spectrometry

International Nuclear Information System (INIS)

Araujo, Miriam Taina Ferreira de; Silva, Ronaldo Lins da; Poledna, Roberto; Delgado, Jose Ubiratan; Andrade, Erica de Araujo Lima de; Oliveira, Antonio Eduardo de; Laranjeiras, Adilson Silva; Braghirolli, Ana Maria Silveira

2014-01-01

During the process of manufacturing a radiopharmaceutical radionuclide impurities nature can be generated. With the need to meet the standards of ANVISA recommends that applications of doses as low as feasible in patients, the concern comes with a 'boost' that can come from these radionuclidic impurities generated in the production process and or manipulation. For Na[¹²³I] provided by IEN is important to quantify its major impurity, ¹²¹Te as well as gaining a better understanding of the parameters related to the decay scheme, since the data in the literature show discrepancies. (author)

Species removal from aqueous radioactive waste by deep-bed filtration.

Science.gov (United States)

Dobre, Tănase; Zicman, Laura Ruxandra; Pârvulescu, Oana Cristina; Neacşu, Elena; Ciobanu, Cătălin; Drăgolici, Felicia Nicoleta

2018-05-26

Performances of aqueous suspension treatment by deep-bed sand filtration were experimentally studied and simulated. A semiempirical deterministic model and a stochastic model were used to predict the removal of clay particles (20 μm) from diluted suspensions. Model parameters, which were fitted based on experimental data, were linked by multiple linear correlations to the process factors, i.e., sand grain size (0.5 and 0.8 mm), bed depth (0.2 and 0.4 m), clay concentration in the feed suspension (1 and 2 kg p /m 3 ), suspension superficial velocity (0.015 and 0.020 m/s), and operating temperature (25 and 45 °C). These relationships were used to predict the bed radioactivity determined by the deposition of radioactive suspended particles (>50 nm) from low and medium level aqueous radioactive waste. A deterministic model based on mass balance, kinetic, and interface equilibrium equations was developed to predict the multicomponent sorption of 60 Co, 137 Cs, 241 Am, and 3 H radionuclides (0.1-0.3 nm). A removal of 98.7% of radioactive particles was attained by filtering a radioactive wastewater volume of 10 m 3 (0.5 mm sand grain size, 0.3 m bed depth, 0.223 kg p /m 3 suspended solid concentration in the feed suspension, 0.003 m/s suspension superficial velocity, and 25 °C operating temperature). Predicted results revealed that the bed radioactivity determined by the sorption of radionuclides (0.01 kBq/kg b ) was significantly lower than the bed radioactivities caused by the deposition of radioactive particles (0.5-1.8 kBq/kg b ). Copyright © 2018 Elsevier Ltd. All rights reserved.

Radionuclide usage survey 1979-80

International Nuclear Information System (INIS)

Woods, M.J.

1980-08-01

Details of a survey by the Life Sciences Working Group of the International Committee for Radionuclide Metrology (ICRM) on radionuclide usage by medical physicists in 11 countries are presented. The results indicate that the radionuclide which will be of most significance in the future will be F-18, Fe-52, Ga-67, Ga-68, Kr-81m, Tc-99m, In-111, I-123, Xe-127 and Tl-201, (U.K.)

Application of a free parameter model to plastic scintillation samples

Energy Technology Data Exchange (ETDEWEB)

Tarancon Sanz, Alex, E-mail: alex.tarancon@ub.edu [Departament de Quimica Analitica, Universitat de Barcelona, Diagonal 647, E-08028 Barcelona (Spain); Kossert, Karsten, E-mail: Karsten.Kossert@ptb.de [Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig (Germany)

2011-08-21

In liquid scintillation (LS) counting, the CIEMAT/NIST efficiency tracing method and the triple-to-double coincidence ratio (TDCR) method have proved their worth for reliable activity measurements of a number of radionuclides. In this paper, an extended approach to apply a free-parameter model to samples containing a mixture of solid plastic scintillation microspheres and radioactive aqueous solutions is presented. Several beta-emitting radionuclides were measured in a TDCR system at PTB. For the application of the free parameter model, the energy loss in the aqueous phase must be taken into account, since this portion of the particle energy does not contribute to the creation of scintillation light. The energy deposit in the aqueous phase is determined by means of Monte Carlo calculations applying the PENELOPE software package. To this end, great efforts were made to model the geometry of the samples. Finally, a new geometry parameter was defined, which was determined by means of a tracer radionuclide with known activity. This makes the analysis of experimental TDCR data of other radionuclides possible. The deviations between the determined activity concentrations and reference values were found to be lower than 3%. The outcome of this research work is also important for a better understanding of liquid scintillation counting. In particular the influence of (inverse) micelles, i.e. the aqueous spaces embedded in the organic scintillation cocktail, can be investigated. The new approach makes clear that it is important to take the energy loss in the aqueous phase into account. In particular for radionuclides emitting low-energy electrons (e.g. M-Auger electrons from {sup 125}I), this effect can be very important.

Radionuclides: Accumulation and Transport in Plants.

Science.gov (United States)

Gupta, D K; Chatterjee, S; Datta, S; Voronina, A V; Walther, C

Application of radioactive elements or radionuclides for anthropogenic use is a widespread phenomenon nowadays. Radionuclides undergo radioactive decays releasing ionizing radiation like gamma ray(s) and/or alpha or beta particles that can displace electrons in the living matter (like in DNA) and disturb its function. Radionuclides are highly hazardous pollutants of considerable impact on the environment, food chain and human health. Cleaning up of the contaminated environment through plants is a promising technology where the rhizosphere may play an important role. Plants belonging to the families of Brassicaceae, Papilionaceae, Caryophyllaceae, Poaceae, and Asteraceae are most important in this respect and offer the largest potential for heavy metal phytoremediation. Plants like Lactuca sativa L., Silybum marianum Gaertn., Centaurea cyanus L., Carthamus tinctorius L., Helianthus annuus and H. tuberosus are also important plants for heavy metal phytoremediation. However, transfer factors (TF) of radionuclide from soil/water to plant ([Radionuclide]plant/[Radionuclide]soil) vary widely in different plants. Rhizosphere, rhizobacteria and varied metal transporters like NRAMP, ZIP families CDF, ATPases (HMAs) family like P1B-ATPases, are involved in the radio-phytoremediation processes. This review will discuss recent advancements and potential application of plants for radionuclide removal from the environment.

Method of separating short half-life radionuclides from a mixture of radionuclides

Science.gov (United States)

Bray, L.A.; Ryan, J.L.

1999-03-23

The present invention is a method of removing an impurity of plutonium, lead or a combination thereof from a mixture of radionuclides that contains the impurity and at least one parent radionuclide. The method has the steps of (a) insuring that the mixture is a hydrochloric acid mixture; (b) oxidizing the acidic mixture and specifically oxidizing the impurity to its highest oxidation state; and (c) passing the oxidized mixture through a chloride form anion exchange column whereupon the oxidized impurity absorbs to the chloride form anion exchange column and the {sup 229}Th or {sup 227}Ac ``cow`` radionuclide passes through the chloride form anion exchange column. The plutonium is removed for the purpose of obtaining other alpha emitting radionuclides in a highly purified form suitable for medical therapy. In addition to plutonium, lead, iron, cobalt, copper, uranium, and other metallic cations that form chloride anionic complexes that may be present in the mixture are removed from the mixture on the chloride form anion exchange column. 8 figs.

Radionuclide transport processes in terrestrial ecosystems

International Nuclear Information System (INIS)

Whicker, F.W.

1983-01-01

Some major principles and the status of knowledge concerning the transport of radionuclides through terrestrial ecosystems are reviewed. Fundamental processes which control the flow of radionuclides between ecosystem components such as air, soil, plants, and animals are described, with emphasis on deposition, resuspension, plant uptake, ingestion, and assimilation. Properties of radionuclides, organisms, and ecosystems are examined in relation to their influence on the accumulation of radioactive materials by plants and animals. The effects of the physicochemical nature of the radionuclide; morphology, physiology, and behavior of the organism; and soil, nutrient, and trophic characteristics of the ecosystem are highlighted. Observations in natural ecosystems on radionuclides such as 137 Cs, 90 Sr, 131 I, 3 H, and 239 Pu are used to illustrate current concepts. An assessment of the degree to which the processes controlling radionuclide behavior are understood and of our ability to simulate and predict such behavior with computerized models is offered. Finally, brief comments are made on research needs

Approaches to modelling radionuclide transfer in agricultural systems

International Nuclear Information System (INIS)

Mitchell, N. G.

1995-01-01

Radiological dose assessment requires information describing the concentration and distribution of radionuclides in the environment. This information can be obtained from monitoring but is also evaluated with the aid of mathematical models. In such models the pathways of radionuclides from the release point to man are described in terms of transfer between compartments. The main pathways to be considered include: deposition to vegetation and soils; transfer from soil-to-plant; uptake and turnover in domestic animals; and, intake by man. The development of mathematical models for simulating transfer via these pathways depends on: an understanding of the system under study, in particular for those processes that are most important in the overall transfer to man; the availability of data to determine the structure and parameters for the model; the computing systems available; the knowledge of the user of the model; and, the application of the model. (author)

Modelling aqueous corrosion of nuclear waste phosphate glass

Energy Technology Data Exchange (ETDEWEB)

Poluektov, Pavel P.; Schmidt, Olga V.; Kascheev, Vladimir A. [Bochvar All-Russian Scientific Research Institute for Inorganic Materials (VNIINM), Moscow (Russian Federation); Ojovan, Michael I., E-mail: m.ojovan@sheffield.ac.uk [Immobilisation Science Laboratory, Department of Materials Science and Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD (United Kingdom)

2017-02-15

A model is presented on nuclear sodium alumina phosphate (NAP) glass aqueous corrosion accounting for dissolution of radioactive glass and formation of corrosion products surface layer on the glass contacting ground water of a disposal environment. Modelling is used to process available experimental data demonstrating the generic inhibiting role of corrosion products on the NAP glass surface. - Highlights: • The radionuclides yield is determined by the transport from the glass through the surface corrosion layer. • Formation of the surface layer is due to the dissolution of the glass network and the formation of insoluble compounds. • The model proposed accounts for glass dissolution, formation of corrosion layer, specie diffusion and chemical reactions. • Analytical solutions are found for corrosion layer growth rate and glass components component leaching rates.

Study on experimental models to analyze radionuclide migration behaviors through porous geologic media

International Nuclear Information System (INIS)

Tanaka, Tadao; Mukai, Masayuki

2012-08-01

The migration phenomenon of radionuclide through geological media such as soils and porous rocks, which is important in underground disposal of radioactive wastes, can be described by the advection-dispersion of groundwater and the interactions of radionuclide with geological media. On the other hand, to understand the migration phenomenon, actual migration data are experimentally acquired by a batch test, a column test and field trial. In the present study, experimental models about the interactions of radionuclide between the solid phase and the liquid phase were discussed systematically to interpret the migration data acquired by the various techniques and conditions. Equilibrium, reversibility, linearity, mechanism and chemistry in the interactions were considered in discussion of the experimental models. A calculation program, which can analyze migration data obtained under various conditions by applying the selected 9 types of experimental models, was maintained. The calculation program makes it be able to predict the migration behavior of radionuclide under various conditions and to decide the important parameter by a fitting analysis of the migration data. (author)

Experimental and modelling studies of radionuclide migration from contaminated groundwaters

International Nuclear Information System (INIS)

Tompkins, J. A.; Butler, A. P.; Wheater, H. S.; Shaw, G.; Wadey, P.; Bell, J. N. B.

1994-01-01

Lysimeter-based studies of radionuclide uptake by winter wheat are being undertaken to investigate soil-to-plant transfer processes. A five year multi-disciplinary research project has concentrated on the upward migration of contaminants from near surface water-tables and their subsequent uptake by a winter wheat crop. A weighted transfer factor approach and a physically based modelling methodology, for the simulation and prediction of radionuclide uptake, have been developed which offer alternatives to the traditional transfer factor approach. Integrated hydrological and solute transport models are used to simulate contaminant movement and subsequent root uptake. This approach enables prediction of radionuclide transport for a wide range of soil, plant and radionuclide types. This paper presents simulated results of 22 Na plant uptake and soil activity profiles, which are verified with respect to lysimeter data. The results demonstrate that a simple modelling approach can describe the variability in radioactivity in both the harvested crop and the soil profile, without recourse to a large number of empirical parameters. The proposed modelling technique should be readily applicable to a range of scales and conditions, since it embodies an understanding of the underlying physical processes of the system. This work constitutes part of an ongoing research programme being undertaken by UK Nirex Ltd., to assess the long term safety of a deep level repository for low and intermediate level nuclear waste. (author)

Radionuclide Sensors for Water Monitoring

International Nuclear Information System (INIS)

Grate, Jay W.; Egorov, Oleg B.; DeVol, Timothy A.

2004-01-01

Radionuclide contamination in the soil and groundwater at U.S. Department of Energy (DOE) sites is a severe problem that requires monitoring and remediation. Radionuclide measurement techniques are needed to monitor surface waters, groundwater, and process waters. Typically, water samples are collected and transported to an analytical laboratory, where costly radiochemical analyses are performed. To date, there has been very little development of selective radionuclide sensors for alpha- and beta-emitting radionuclides such as 90Sr, 99Tc, and various actinides of interest. The objective of this project is to investigate novel sensor concepts and materials for sensitive and selective determination of beta- and alpha-emitting radionuclide contaminants in water. To meet the requirements for loW--level, isotope-specific detection, the proposed sensors are based on radiometric detection. As a means to address the fundamental challenge of the short ranges of beta and alpha particle s in water, our overall approach is based on localization of preconcentration/separation chemistries directly on or within the active area of a radioactivity detector. Automated microfluidics is used for sample manipulation and sensor regeneration or renewal. The outcome of these investigations will be the knowledge necessary to choose appropriate chemistries for selective preconcentration of radionuclides from environmental samples, new materials that combine chemical selectivity with scintillating properties, new materials that add chemical selectivity to solid-state diode detectors, new preconcentrating column sensors, and improved instrumentation and signal processing for selective radionuclide sensors. New knowledge will provide the basis for designing effective probes and instrumentation for field and in situ measurements

Radionuclides in terrestrial ecosystems

International Nuclear Information System (INIS)

Bocock, K.L.

1981-01-01

This report summarizes information on the distribution and movement of radionuclides in semi-natural terrestrial ecosystems in north-west England with particular emphasis on inputs to, and outputs from ecosystems; on plant and soil aspects; and on radionuclides in fallout and in discharges by the nuclear industry. (author)

Artificial radionuclides in soil, flora and fauna

International Nuclear Information System (INIS)

Marej, A.N.

1984-01-01

Sources and ways of soil contamination by radionuclides, as well as the main regularities of radionuclide behaviour in soils, are discussed. Ways of radionuclide uptake by plants are discussed in detail, since radionuclide contamination of vegetation, and agricultural plants and pastures in particular, is one of the main factors, determining sanitary value of environmental contamination by radioactive substances

γ-radiation effect on dicyclohexano-18-crown-6 aqueous solution in the presence of metal cations

Energy Technology Data Exchange (ETDEWEB)

Yu, Chuhong; Peng, Jing; Li, Jiuqiang; Zhai, Maolina [Peking Univ. (China). Beijing National Laboratory for Molecular Sciences (BNLMS)

2014-04-01

γ-radiation effect on dicyclohexano-18-crown-6 (DCH18C6) aqueous solution in the presence of metal cations, such as K{sup +} and Sr{sup 2+}, was investigated, and some pale yellow precipitates were obtained at doses above 100 kGy. It was found that the complexation interaction of metal cations could accelerate the conversion of DCH18C6 into oligomers and the formation of precipitates, but it did not affect the formation mechanism of precipitates. Furthermore, the salting-out effect of metal cations played an important role in the precipitation. In order to inhibit the radiation-induced precipitation of DCH18C6 in water phase, nitric acid with a concentration of more than 1 M could be added to the system. The methods and results for analyzing radiation-induced products reported in this work are useful to understand the radiation chemistry behavior of DCH18C6 which is used as the extractant in the separation of long half-life radionuclides from spent nuclear fuel. (orig.)

MARFA version 3.2.2 user's manual: migration analysis of radionuclides in the far field

International Nuclear Information System (INIS)

Painter, Scott; Mancillas, James

2009-12-01

concentration. Nonlinear processes such as solubility-limited transport or aqueous speciation are not represented. The MARFA code is specifically designed to work with output from discrete fracture network (DFN), continuous porous medium (CPM), or nested DFN/CPM flow models. Transport is assumed to occur along a set of trajectories or pathways that originate at radionuclide source locations. Trajectories are intended to represent the movement of hypothetical, advectively transported groundwater tracers and are typically calculated by pathline tracing in a DFN or DFN/CPM flow code. MARFA supports an arbitrary number of trajectories and source locations

Macroscopic and spectroscopic investigations on the immobilization of radionuclides by hardened cement paste

International Nuclear Information System (INIS)

Wieland, E.; Bonhoure, I.; Tits, J.; Scheidegger, A.M.; Bradbury, M.H.

2002-01-01

The uptake of safety-relevant radionuclides was studied using a combination of macroscopic (wet chemistry) and spectroscopic (X-ray absorption fine structure (XAFS) spectroscopy) techniques with the aim of gaining a mechanistic understanding of the uptake processes on hardened cement paste (HCP) and deducing robust sets of sorption values. HCP contains impurities of metal cations in the ppb to ppm concentration range. As a consequence, the inventories of stable isotopes are expected to be significant in a cementitious near-field and may even exceed the radionuclide inventories of the waste matrix for many safety-relevant radioelements. In view of the significant inventories of stable isotopes, it is suggested that isotopic exchange - replacement of stable isotopes by their radioactive counterparts in the cement matrix - is an important immobilisation process in HCP. However, it is not a priori known what proportion of each elemental inventory is available for isotopic exchange. Wet chemistry studies with Cs and Sr show that the total inventory of these elements is reversibly bound and that their partitioning between HCP and pore water can be modelled using the distribution values deduced from studies of the corresponding tracers ( 137 Cs and 85 Sr). This finding corroborates the relevance of isotopic exchange in cementitious systems. Wet chemistry investigations need to be complemented by spectroscopic techniques, e.g., XAFS, in order to gain a mechanistic understanding of the chemical processes by which waste ions become immobilised in cement-based matrices. XAFS can be used to obtain information at the atomic/molecular level, i.e., the type, number and distance of neighbouring atoms. XAFS studies on cementitious systems are still rather rare, and therefore information on the potential and limitations of this technique is sparse. Mechanistic aspects of the immobilisation processes are discussed for some safety-relevant radionuclides (e.g. Ni and Sr) using the

Bentonite erosion: effects on the long term performance of the engineered barrier and radionuclide transport - The BELBAR project

International Nuclear Information System (INIS)

Sellin, P.; Sundman, D.; Bailey, L.; Missana, T.; Schaefer, T.; Cervinka, R.; Koskinen, K.

2012-01-01

is to consider how colloids and related phenomena can be considered in the long-term safety case, to 1 million years following the closure of a geological repository, and to make recommendations on the quantitative and qualitative approaches that a safety case could pursue to adequately address this issue. The main objective of WP2 will be to understand the main mechanisms of erosion of clay particles from the bentonite surface and to quantify the (maximum) extent of the possible erosion under different physico-chemical conditions. Additionally, these studies will point out under what conditions compacted bentonite is able to produce colloidal particles, free to move into the contacting aqueous phase and to determine the bentonite colloids 'source-term'. Potentially relevant physico-chemical factors to the bentonite erosion processes will be studied in an extensive experimental programme. Clay colloids potentially generated in the nuclear waste repository near-field from the bentonite-buffer/ backfill material might be stable under the geochemical conditions of the fractured rock far-field and could be a carrier of radionuclides. WP3 will focus on the process understanding of colloid mobility controlling processes and their appropriate description, the reversibility of the sorption of radionuclides onto colloids and the kinetics of the sorption/desorption process as well as the identification of additional retention processes. The potential release of divalent cations (Ca 2+ , Mg 2+ ) via matrix diffusion is expected to increase the colloid attachment probability and reduce the colloid mobility. WP4 focuses on clay colloid stability studies under different geochemical conditions with respect to ionic strength and pH. The colloids formed at the near/far field interface would be stable only if favourable conditions exist and therefore their relevance for radionuclide transport will be strongly site-specific. The experimental work will be concentrated on effects of

Environmental behaviour of radionuclides and transfer to man

International Nuclear Information System (INIS)

Smith, H.

1982-01-01

The environmental behaviour of the radionuclides making the major contribution to man's irradiation through diet is described. The following stages are emphasized: transfer of radionuclides to plants; transfer of radionuclides to animals; metabolism of inhaled or ingested radionuclides in animals providing food for man; transfer of radionuclides through the aquatic environment; application of food chain models. (43 references)

Radioactivity: radionuclides in foods

International Nuclear Information System (INIS)

Simpson, R.E.; Baratta, E.J.; Jelinek, C.F.

1977-01-01

The results are summarized of the analysis for strontium-90, cesium-137, iodine-131, ruthenium-106, and potassium-40, a naturally occurring radionuclide, in samples of total diet and selected import commodities in the foods compliance program of the Food and Drug Administration. On the basis of the radionuclide intake guidelines established by the Federal Radiation Council (FRC), the low content of radionuclides found in the total diet samples for fiscal years 1973 and 1974 demonstrates the need for surveillance only at the present level. The low levels of radionuclides found in a limited number of edible imported commodities indicate that their contribution to the total diet would not increase the levels of these radionuclides above those recommended for only periodic surveillance by the FRC. The potassium levels, determined from potassium-40 activity, found in meats and fish agree with the value for normal muscle tissue for the reference man reported by the International Commission on Radiation Protection. Of the other commodities, nuts contained the highest levels, while sugar, beverages, and processed foods contained the lowest levels of potassium. Although cesium and potassium are chemical analogs with similar metabolic properties, because of their variable content in some leafy samples as a result of surface contamination, a correlation between cesium-137 levels and the cesium-137-to-potassium ratio was inconclusive

Inverse problem in radionuclide transport

International Nuclear Information System (INIS)

Yu, C.

1988-01-01

The disposal of radioactive waste must comply with the performance objectives set forth in 10 CFR 61 for low-level waste (LLW) and 10 CFR 60 for high-level waste (HLW). To determine probable compliance, the proposed disposal system can be modeled to predict its performance. One of the difficulties encountered in such a study is modeling the migration of radionuclides through a complex geologic medium for the long term. Although many radionuclide transport models exist in the literature, the accuracy of the model prediction is highly dependent on the model parameters used. The problem of using known parameters in a radionuclide transport model to predict radionuclide concentrations is a direct problem (DP); whereas the reverse of DP, i.e., the parameter identification problem of determining model parameters from known radionuclide concentrations, is called the inverse problem (IP). In this study, a procedure to solve IP is tested, using the regression technique. Several nonlinear regression programs are examined, and the best one is recommended. 13 refs., 1 tab

Radionuclide Retention in Concrete Wasteforms

Energy Technology Data Exchange (ETDEWEB)

Wellman, Dawn M.; Jansik, Danielle P.; Golovich, Elizabeth C.; Cordova, Elsa A.

2012-09-24

Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. Data collected throughout the course of this work will be used to quantify the efficacy of concrete wasteforms, similar to those used in the disposal of LLW and MLLW, for the immobilization of key radionuclides (i.e., uranium, technetium, and iodine). Data collected will also be used to quantify the physical and chemical properties of the concrete affecting radionuclide retention.

Assessment of the concentration limits for radionuclides for Posiva

Energy Technology Data Exchange (ETDEWEB)

Grive, M.; Montoya, V.; Duro, L. (Enviros Spain S.L. (Spain))

2007-01-15

The present document assesses the near-field concentration limits of the radionuclides of interest for Posiva (C, Ni, Se, Sr, Mo, Zr, Nb, Tc, Pd, Sn, Cs, Sm, Ra, Th, Pa, U, Pu, Np, Am and Cm) under the geochemical composition of the Olkiluoto groundwaters. The limits provided here are intended to be used only in the area close to the fuel given that no major solid phases other than the ones produced by the anoxic corrosion of the canister and the fuel itself are considered. Calculations have been performed by using the PHREEQC code. Three different general cases have been considered when assessing the composition of the groundwater contacting the fuel: a) Groundwater contacts the fuel without any prior interaction with the buffer b) Groundwater is modified by interaction with Bentonite, and c) Glacial meltwater reaches the fuel. The redox state of the system has been considered to cover different evolution of the repository for the different groundwaters. Besides of the given redox potential of the groundwaters, two variations of the redox state have been accounted for in this analysis to consider the evolution of H{sub 2} due to the anoxic corrosion of the cast iron insert: (a) The maximum pH{sub 2} overpressure is limited by the hydrostatic and swelling pressure of bentonite at repository depth, and (b) The pH{sub 2} overpressure is limited by the hematite/magnetite stability boundary. This exemplifies the corrosion of iron to magnetite in a first step, and its further evolution to hematite in a second step. Tables summarizing the solubility and aqueous speciation of the different waters as well as the main uncertainty parameters affecting the results are provided. The concentration limits recommended in this report are based on the following assumptions: (i) radionuclides will form individual solid phases, and (ii) the rate of dissolution of radionuclides from spent fuel is fast enough as to ensure that equilibrium with individual solid phases is achieved for

Assessment of the concentration limits for radionuclides for Posiva

International Nuclear Information System (INIS)

Grive, M.; Montoya, V.; Duro, L.

2008-01-01

The present document assesses the near-field concentration limits of the radionuclides of interest for Posiva (C, Ni, Se, Sr, Mo, Zr, Nb, Tc, Pd, Sn, Cs, Sm, Ra, Th, Pa, U, Pu, Np, Am and Cm) under the geochemical composition of the Olkiluoto groundwaters. The limits provided here are intended to be used only in the area close to the fuel given that no major solid phases other than the ones produced by the anoxic corrosion of the canister and the fuel itself are considered. Calculations have been performed by using the PHREEQC code. Three different general cases have been considered when assessing the composition of the groundwater contacting the fuel: a) Groundwater contacts the fuel without any prior interaction with the buffer b) Groundwater is modified by interaction with Bentonite, and c) Glacial meltwater reaches the fuel. The redox state of the system has been considered to cover different evolution of the repository for the different groundwaters. Besides of the given redox potential of the groundwaters, two variations of the redox state have been accounted for in this analysis to consider the evolution of H 2 due to the anoxic corrosion of the cast iron insert: (a) The maximum pH 2 overpressure is limited by the hydrostatic and swelling pressure of bentonite at repository depth, and (b) The pH 2 overpressure is limited by the hematite/magnetite stability boundary. This exemplifies the corrosion of iron to magnetite in a first step, and its further evolution to hematite in a second step. Tables summarizing the solubility and aqueous speciation of the different waters as well as the main uncertainty parameters affecting the results are provided. The concentration limits recommended in this report are based on the following assumptions: (i) radionuclides will form individual solid phases, and (ii) the rate of dissolution of radionuclides from spent fuel is fast enough as to ensure that equilibrium with individual solid phases is achieved for times shorter

Introduction to the special issue: 11. International Conference on Health Effects of Incorporated Radionuclides

International Nuclear Information System (INIS)

Ansoborlo, Eric; Menager, Marie-Therese; Abergel, Rebecca J.

2014-01-01

The 11. International Conference on Healths of Incorporated Radionuclides (HEIR 2013) took place in Berkeley (US) over four days in October 2013. It was co-organized by the Lawrence Berkeley National Laboratories (LBNL, US) and the Commissariat a l'Energie Atomique et aux Energies Alternatives (CEA, France). The HEIR 2013 was well attended and hosted about 90 scientists from 10 different countries. Forty oral presentations were given over the four days and 25 posters were discussed during two poster sessions. About a third of these contributions resulted in publications included in the present special issue, comprising most of the topics addressed at the meeting. Contributions and discussions spanned a variety of fields and were organized along the following four main scientific themes: 1) epidemiology, biological effects and dose assessment 2) bio-dosimetry, molecular biology and biochemistry 3) biokinetics 4) medical countermeasures and decorporation. Among the many important concepts and results treated during the conference, the following points can be highlighted: 1)the first reports on the effects of radiation and radionuclide contamination in Fukushima from the World Health Organization (WHO) and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) allow assessing the current situation and health risks, three years after the power plant accident. Such events raise the significance of science-based findings to delineate the health risks for population exposed to radionuclides. 2)While most studies in the past decades have focused on the effects of acute or single exposure to radionuclides, few controlled studies have investigated the health impacts on chronic exposure to radioisotopes. Recent work on chronic cesium or uranium ingestion performed at the French Institute for Radioprotection and Nuclear Safety are reported. 3)The need for a good understanding of radionuclide speciation in biokinetic studies was emphasized and

Hydrologic and geochemical controls on the transport of radionuclides in natural undisturbed arid environments as determined by accelerator mass spectrometry measurements

International Nuclear Information System (INIS)

Nimz, G; Caffee, M W; McAninch, J

2000-01-01

This project developed techniques for measuring globally distributed radionuclides that occur today in extremely low abundances (''fallout'' from the era of atmospheric nuclear testing), and then applied these techniques to better understand the mechanisms by which radionuclides migrate. The techniques employ accelerator mass spectrometry (AMS), a relatively new analytical tool that permits this work to be conducted for the first time. The goal in this project was to develop AMS analytical techniques for 129 I (fallout concentration: ∼ 10 6 atoms/g) 99 Tc (∼ 10 9 atoms/g), 90 Sr (∼10 7 atoms/gram soil), and 93 Zr (∼ 10 9 atoms/g), and improved methods for 36 Cl (∼ 10 9 atoms/g). As a demonstration of the analytical techniques, and as an investigation of identified problems associated with characterizing moisture and radionuclide movement in unsaturated desert soils, we developed a vadose zone research site at the Nevada Test Site. Our findings can be summarized as follows: (1) The distribution of chloride and 36 Cl at the research site indicates that the widely-used ''chloride accumulation'' method for estimating moisture flux is erroneous; some mechanism for attenuation of chloride exists, violating an assumption of the accumulation method; (2) 129 I is fractionated into several soil compartments that have varying migration abilities; the two most mobile can be tentatively identified as Fe/Mn oxyhydroxides and organic acids based on our sequential leaching techniques; (3) These most mobile constituents are capable of migrating at a rate greater than that of 36 Cl, usually considered the most mobile solute in hydrologic systems; these constituents may be colloidal in character, of neutral surface charge, and therefore conservative in aqueous migration; (4) 99 Tc is readily measurable by AMS, as we demonstrate by the first AMS 99 Tc measurements of contaminated waters; extraction of 99 Tc from silicate soils is difficult, but can be done using the extended

Basic microscopic theory of the distribution, transfer and uptake kinetics of dissolved radionuclides by suspended particulate matter - Part I; Theory development

International Nuclear Information System (INIS)

Abril, J.M.

1998-01-01

Recently much experimental effort has been focused on determining those factors which affect the kinetics and the final equilibrium conditions for the uptake of radionuclides from the aqueous phase by particulate matter. At present, some of these results appear to be either surprising or contradictory and introduce some uncertainty in which parameter values are most appropriate for environmental modelling. In this paper, we study the ionic exchange between the dissolved phase and suspended particles from a microscopic viewpoint, developing a mathematical description of the kinetic transfer and the k d distribution coefficients. The most relevant contribution is the assumption that the exchange of radionuclides occurs in a specific surface layer on the particles, with a non-zero thickness. A wide range of experimental findings can be explained with this theory. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

The radionuclide migration experiment - overview of investigations 1985 - 1990

International Nuclear Information System (INIS)

Frick, U.; McKinley, I.G.; Baeyens, B.; Bradbury, M.H.; Eikenberg, J.; Heer, W.; Hoehn, E.; Smith, P.A.; Alexander, W.R.; Bossart, P.; Buehler, C.; Fierz, T.

1992-03-01

This paper provides an overview of the investigations conducted from 1985 to 1990 as a part of the radionuclide migration experiment which is currently in progress in the Nagra underground research laboratory at the Grimsel pass in the Central Swiss Alps. The major aims of the project are (1) to test the extrapolation of laboratory sorption data to field conditions, (2) to analyse retardation processes in a fractured rock, (3) to improve and develop the necessary methodologies for site characterization and (4) to test existing geochemical, hydrodynamic, and solute transport models or their associated data bases. Field and modeling work are complemented by an extensive laboratory support programme. The Grimsel migration experiment demonstrates conclusively how the combined efforts of modeling, laboratory and field investigations can substantially widen the understanding of radionuclide transport in a geological environment. (author) figs., tabs., refs

Measurement of radionuclides in waste packages

Science.gov (United States)

Brodzinski, R.L.; Perkins, R.W.; Rieck, H.G.; Wogman, N.A.

1984-09-12

A method is described for non-destructively assaying the radionuclide content of solid waste in a sealed container by analysis of the waste's gamma-ray spectrum and neutron emissions. Some radionuclides are measured by characteristic photopeaks in the gamma-ray spectrum; transuranic nuclides are measured by neutron emission rate; other radionuclides are measured by correlation with those already measured.

Electrochemical reactions of uranyl(VI) complexes in aqueous solution, non-aqueous solvents, and ionic liquids

International Nuclear Information System (INIS)

Ikeda, Yasuhisa

2006-01-01

Author's recent experimental results on the chemistry of U(V) in aqueous solution, non-aqueous solvents, and ionic solvents by cyclic voltametry are described. The U(V) was produced by electrochemical reduction of uranyl U(VI) ions or complexes such as carbonates, DMF(N, N-dimethylformamide), DMSO(dimethylsulfoxide), acetylacetonato, and other organic polydental ligands. The produced U(V) complexes were studied by spectrophotometry using optical-transmission thin-layer electrode. The U(V) complexes in non-aqueous solvents were found to be rather stable, they undergo ligand-dissociation reaction but not disproportionation reaction. The structure and electronic spectra as well as IR spectra of the complexes were studied. The present method was further developed to study the behavior of U(V) complexes in ionic liquids as molten salts, e.g., alkaline metals chlorides. Thus, the present research contributes to understanding the chemistry of 5fl system. Application to such nuclear technology as spent fuel reprocessing is discussed. (S. Ohno)

Overview of exposure to and effects from radionuclides in terrestrial and marine environments.

Science.gov (United States)

Sample, Bradley E

2011-07-01

The accident at the Fukushima Daiichi nuclear power plant, precipitated by the devastating earthquake and subsequent tsunami that struck the northeastern coast of Japan in March 2011, has raised concerns about potential impacts to terrestrial and marine environments from radionuclides released into the environment. A preliminary understanding of the potential ecological impacts from radionuclides can be ascertained from observations and data developed following previous environmental incidents elsewhere in the world. This article briefly summarizes how biota experience exposure to ionizing radiation, what effects may be produced, and how they may differ among taxa and habitats. Copyright © 2011 SETAC.

Radionuclide mobility in the shallow portion of an active high-temperature geothermal system

International Nuclear Information System (INIS)

Sturchio, N.C.; Seitz, M.G.

1984-01-01

Accurate knowledge of the behavior of radionuclides in natural rock-water systems is crucial for the prediction of the consequences of failure of a high-level nuclear waste repository. Work in progress at Argonne National Laboratory involves the detailed geochemical analysis of rock, mineral, and water samples from shallow drill holes in a thermal area of Yellowstone National Park. This study is designed to provide data that will increase our understanding of the behavior of a group of radionuclides in an environment similar to that of the near field of a high-level nuclear waste repository

Speciation of radionuclides in the environment

International Nuclear Information System (INIS)

Gunten, H.R. von; Benes, P.

1994-02-01

Methods for the determination of the speciation of radionuclides in aerosols, in aquatic solutions, in sediments, soils and rocks are reviewed. At present, most of the results about speciation are deduced from model calculations, model experiments, and separation of species (forms) of radionuclides, e.g., by sequential extraction procedures. Methods of direct determination of speciation of radionuclides (e.g. by laser induced spectroscopy) are in general not yet sensitive enough for a measurement of the very low concentrations of radionuclides in the environment. The methodological part of this paper is followed by a review of the very abundant literature about speciation of important radionuclides in the environment, i.e. in the atmosphere, hydrosphere and lithosphere. The review does not include the biosphere. Literature up to spring 1993 is included (with a few more recent additions). (author)

Radionuclide transport in a single fissure

International Nuclear Information System (INIS)

Eriksen, T.E.

1983-01-01

Radionuclide migration have been studied in natural fissures orieted parallel to the axis of granite drill cores. A short pulse of the radionuclides solution was injected at one end of the fissure and the temporal change in radionuclide concentration of the eluate measured. After several hundred fissure volumes water had been pumped through the fissure following the radionuclide pulse the activity distribution on the fissure surfaces was measured. From the retardation of 152 Eu, 235 Np and 237 Pu it is concluded that these radionuclides are transported in the oxidation states Eu(III), Pu(IV) and Np(V). The distribution coefficients K sub (d) calculated from flow and activity distribution data on the basis of geometric surface area/volume ratios are of the same order as published K sub (d) values obtained from batch equilibrium experiments. (Author)

A study of radionuclide dispersion by river systems, using GIS and remote sensing techniques

International Nuclear Information System (INIS)

Borghuis, Sander; Brown, Justin; Steenhuisen, Frits; Skorve, Johnny

2000-01-01

The Krasnoyarsk Mining and Chemical Combine in Zheleznogorsk, Russia, is situated on the banks of the Yenisey river. The combine consists of three RBMK-type graphite moderate reactors, a reprocessing plant for the production of weapons-grade plutonium and storage facilities for nuclear waste. Discharges of radionuclides into the Yenisey river were either part of normal operation procedures or caused by accidental releases (Strand et al., 1997). So far, little is known about the transport and fate of the radioactive contaminants in the areas downstream of the Krasnoyarsk CC that are influenced by the Yenisey river system. Aim is to comprehend the dispersion of radionuclides through the river system. Remotely sensed and field study information are combined in a geographical information system (GIS) to study the processes leading to the dispersion of sediment-bound radionuclides carried by the river system. Since the extent of the study area is several thousands or kilometres of river and adjacent flood plains, use is made of a record of remotely sensed (satellite) images that are handled by the GIS. Panchromatic, high resolution satellite images as well as multispectral Landsat MSS and TM images were compiled for the area of interest. The panchromatic images were taken in a period during which the facility was in operation (1960-1972) and obtained for intervals of circa 6 months. A time series of satellite images enables the identification of erosion and sedimentation zones. The behaviour and fate of particle-reactive radionuclides, e.g. 239,240 Pu and to large extent 137 Cs, will be closely related to the movement of sediment. With respect to the behaviour and fate of more conservative radionuclides as 90 Sr, information is required accounting for fractionation between the particulate and aqueous phases. Stereo images are used to comprehend the geomorphology of the Yenisey river systems, focused on classification of sedimentary deposits. Landsat MSS and TM with five

Measurement of anthropogenic radionuclides in the atmosphere with a radionuclide monitoring network for nuclear tests

International Nuclear Information System (INIS)

Yonezawa, Chushiro; Yamamoto, Yoichi

2011-01-01

A worldwide radionuclide monitoring network for nuclear tests has detected the anthropogenic radioactive materials released in the atmosphere due to the accident of the Fukushima Daiichi Nuclear Power Plant impacted by the Great East Japan Earthquake on March 11, 2011. After four months have passed since the accident occurred, most overseas stations do not detect the radionuclides of Fukushima origin any more. The Takasaki station in Japan, however, is still detecting them every day. This paper describes radionuclide monitoring stations and the network of them as part of the International Monitoring System (IMS) in the Comprehensive Nuclear Test Ban Treaty (CTBT), as well as the measurement results of radionuclide particulates and radioactive isotopes of xenon released from the Fukushima Daiichi Nuclear Power Plant with the monitoring network. (J.P.N.)

Radionuclide behavior in water saturated porous media: Diffusion and infiltration coupling of thermodynamically and kinetically controlled radionuclide water - mineral interactions

International Nuclear Information System (INIS)

Spasennykh, M.Yu.; Apps, J.A.

1995-05-01

A model is developed describing one dimensional radionuclide transport in porous media coupled with locally reversible radionuclide water-mineral exchange reactions and radioactive decay. Problems are considered in which radionuclide transport by diffusion and infiltration processes occur in cases where radionuclide water-solid interaction are kinetically and thermodynamically controlled. The limits of Sr-90 and Cs-137 migration are calculated over a wide range of the problem variables (infiltration velocity, distribution coefficients, and rate constants of water-mineral radionuclide exchange reactions)

A vector Wiener filter for dual-radionuclide imaging

International Nuclear Information System (INIS)

Links, J.M.; Prince, J.L.; Gupta, S.N.

1996-01-01

The routine use of a single radionuclide for patient imaging in nuclear medicine can be complemented by studies employing two tracers to examine two different processes in a single organ, most frequently by simultaneous imaging of both radionuclides in two different energy windows. In addition, simultaneous transmission/emission imaging with dual-radionuclides has been described, with one radionuclide used for the transmission study and a second for the emission study. There is thus currently considerable interest in dual-radionuclide imaging. A major problem with all dual-radionuclide imaging is the crosstalk between the two radionuclides. Such crosstalk frequently occurs, because scattered radiation from the higher energy radionuclide is detected in the lower energy window, and because the lower energy radionuclide may have higher energy emissions which are detected in the higher energy window. The authors have previously described the use of Fourier-based restoration filtering in single photon emission computed tomography (SPECT) and positron emission tomography (PET) to improve quantitative accuracy by designing a Wiener or other Fourier filter to partially restore the loss of contrast due to scatter and finite spatial resolution effects. The authors describe here the derivation and initial validation of an extension of such filtering for dual-radionuclide imaging that simultaneously (1) improves contrast in each radionuclide's direct image, (2) reduces image noise, and (3) reduces the crosstalk contribution from the other radionuclide. This filter is based on a vector version of the Wiener filter, which is shown to be superior [in the minimum mean square error (MMSE) sense] to the sequential application of separate crosstalk and restoration filters

Radionuclides in Canada goose eggs

International Nuclear Information System (INIS)

Rickard, W.H.; Sweany, H.A.

1975-01-01

Low levels of radionuclides were measured in Canada goose eggs taken from deserted nests from Columbia River islands on the Energy Research and Development Administration's Hanford Reservation. Potassium-40, a naturally occurring radionuclide, was the most abundant radionuclide measured in egg contents and egg shell. Strontium-90 was incorporated into egg shells and cesium-137 into inner egg contents. Manganese-54, cobalt-60, and zinc-65 were more abundant in inner egg contents than in egg shell. Cerium-144 was detected in egg shell but not in inner shell

Iodine Pathways and Off-Gas Stream Characteristics for Aqueous Reprocessing Plants – A Literature Survey and Assessment

Energy Technology Data Exchange (ETDEWEB)

R. T. Jubin; D. M. Strachan; N. R. Soelberg

2013-09-01

Used nuclear fuel is currently being reprocessed in only a few countries, notably France, England, Japan, and Russia. The need to control emissions of the gaseous radionuclides to the air during nuclear fuel reprocessing has already been reported for the entire plant. But since the gaseous radionuclides can partition to various different reprocessing off-gas streams, for example, from the head end, dissolver, vessel, cell, and melter, an understanding of each of these streams is critical. These off-gas streams have different flow rates and compositions and could have different gaseous radionuclide control requirements, depending on how the gaseous radionuclides partition. This report reviews the available literature to summarize specific engineering data on the flow rates, forms of the volatile radionuclides in off-gas streams, distributions of these radionuclides in these streams, and temperatures of these streams. This document contains an extensive bibliography of the information contained in the open literature.

Uranium and Cesium sorption to bentonite colloids in high salinity and carbonate-rich environments: Implications for radionuclide transport

Science.gov (United States)

Tran, E. L.; Teutsch, N.; Klein-BenDavid, O.; Weisbrod, N.

2017-12-01

When radionuclides are leaked into the subsurface due to engineered waste disposal container failure, the ultimate barrier to migration of radionuclides into local aquifers is sorption to the surrounding rock matrix and sediments, which often includes a bentonite backfill. The extent of this sorption is dependent on pH, ionic strength, surface area availability, radionuclide concentration, surface mineral composition, and solution chemistry. Colloidal-sized bentonite particles eroded from the backfill have been shown to facilitate the transport of radionuclides sorbed to them away from their source. Thus, sorption of radionuclides such as uranium and cesium to bentonite surfaces can be both a mobilization or retardation factor. Though numerous studies have been conducted to-date on sorption of radionuclides under low ionic strength and carbonate-poor conditions, there has been little research conducted on the behavior of radionuclides in high salinities and carbonate rich conditions typical of aquifers in the vicinity of some potential nuclear repositories. This study attempts to characterize the sorption properties of U(VI) and Cs to bentonite colloids under these conditions using controlled batch experiments. Results indicated that U(VI) undergoes little to no sorption to bentonite colloids in a high-salinity (TDS= 9000 mg/L) artificial groundwater. This lack of sorption was attributed to the formation of CaUO2(CO3)22- and Ca2UO2(CO3)3 aqueous ions which stabilize the UO22+ ions in solution. In contrast, Cs exhibited greater sorption, the extent to which was influenced greatly by the matrix water's ionic strength and the colloid concentration used. Surprisingly, when both U and Cs were together, the presence of U(VI) in solution decreased Cs sorption, possibly due to the formation of stabilizing CaUO2(CO3)22- anions. The implications of this research are that rather than undergoing colloid-facilitated transport, U(VI) is expected to migrate similarly to a

Sensors and Automated Analyzers for Radionuclides

International Nuclear Information System (INIS)

Grate, Jay W.; Egorov, Oleg B.

2003-01-01

The production of nuclear weapons materials has generated large quantities of nuclear waste and significant environmental contamination. We have developed new, rapid, automated methods for determination of radionuclides using sequential injection methodologies to automate extraction chromatographic separations, with on-line flow-through scintillation counting for real time detection. This work has progressed in two main areas: radionuclide sensors for water monitoring and automated radiochemical analyzers for monitoring nuclear waste processing operations. Radionuclide sensors have been developed that collect and concentrate radionuclides in preconcentrating minicolumns with dual functionality: chemical selectivity for radionuclide capture and scintillation for signal output. These sensors can detect pertechnetate to below regulatory levels and have been engineered into a prototype for field testing. A fully automated process monitor has been developed for total technetium in nuclear waste streams. This instrument performs sample acidification, speciation adjustment, separation and detection in fifteen minutes or less

of radioconjugated DOTA-1-Nal3-octreotide labeled with gallium-68 using non-aqueous solvents

International Nuclear Information System (INIS)

Pérez-Malo Cruz, Marylaine; Leyva Montaña, René

2016-01-01

Neuroendocrine tumors specifically over-expressing somatostatin receptors. Diagnosis has expanded due to radiolabelling of DOTA-peptides such as somatostatin analogue DOTA-1-Nal 3 -Octreotide (DOTA-NOC) conjugated to β+ emitting radionuclides such as 68 Ga, which has very favorable physics-nuclear properties. This paper describes the radiolabeling procedures of DOTA-NOC with 68 Ga, in pure aqueous medium and in presence of non-aqueous solvents as well as the methods used for quality control where a formulation is obtained with a radiochemical yield exceeding 95%. The addition of ethanol (30% - v / v) to reaction mixture allowed to increase the specific activity of 68 Ga-DOTA-NOC radioconjugate, reaching a value of 182 MBq / nmol, higher than reported in the literature (50 MBq / nmol ) for labeling in pure aqueous medium. Stability studies are also presented (in presence of saline solution and saline phosphate buffer, transmetallation studies in Fe 3+ , Ca 2+ , Mg 2+ and Zn 2+ solutions, challenges competition against EDTA and DTPA chelators and in vitro stability in human transferrin) performed to 68Ga-DOTA-NOC radioconjugated, showing its high stability (> 95%). (author)

Radionuclide deposition control

International Nuclear Information System (INIS)

1980-01-01

A method is described for controlling the deposition, on to the surfaces of reactor components, of the radionuclides manganese-54, cobalt-58 and cobalt-60 from a liquid stream containing the radionuclides. The method consists of disposing a getter material (nickel) in the liquid stream, and a non-getter material (tantalum, tungsten or molybdenum) as a coating on the surfaces where deposition is not desired. The process is described with special reference to its use in the coolant circuit in sodium cooled fast breeder reactors. (U.K.)

Radionuclide transfer

International Nuclear Information System (INIS)

Gerber, G.B.

1993-01-01

The research project described here had the aim to obtain further information on the transfer of nuclides during pregnancy and lactation. The tests were carried out in mini-pigs and rats receiving unchanging doses of radionuclides with the food. The following findings were revealed for the elements examined: Fe, Se, Cs and Zn were characterized by very high transfer levels in the mother, infant and foetus. A substantial uptake by the mother alone was observed for Co, Ag and Mn. The uptake by the foetus and infant here was 1 to 10 times lower. A preferential concentration in certain tissues was seen for Sr and Tc; the thyroid levels of Tc were about equally high in mothers and infants, while Sr showed less accumulation in the maternal bone. The lanthanide group of substances (Ce, Eu and Gd as well as Y and Ru) were only taken up to a very limited extent. The uptake of the examined radionuclides (Fe, Co, Ag, Ce) with the food ingested was found here to be ten times greater in rats as compared to mini-pigs. This showed that great caution must be observed, if the behaviour of radionuclides in man is extrapolated from relevant data obtained in rodents. (orig./MG) [de

Radionuclide retardation project at GTS - An overview of lessons learned and ongoing experiments

International Nuclear Information System (INIS)

Moeri, A.

2001-01-01

The joint Nagra/JNC Radionuclide Migration Programme has now been ongoing for more than 15 years in Nagra's Grimsel Test Site (GTS). The main aim of the programme has been the direct testing of radionuclide transport models in as realistic a manner as possible. The understanding and modelling of both the processes and the structures influencing radionuclide transport/retardation in fractured granitic host rocks have matured as has the experimental technology, which has contributed to develop confidence in the applicability of the underlying research models in a repository performance assessment. In this paper, three in situ experiments which were carried out in a discrete granitic shear zone are briefly presented: The Migration Experiment (MI), the Excavation Experiment (EP) and the ongoing Colloid and Radionuclide Retardation Experiment (CRR). Each project expanded on the experimental experience and research results from the preceding experiment. MI provided a sound data base of in situ tracer breakthrough curves which was used to derive relevant transport parameters by inverse modelling in order to enhance the capability for predictive modelling of tracer transport in a granitic shear zone. The Excavation Project (EP) then focussed on the excavation of the dipole flow field in order to describe the flow paths within the shear zone dipole and the retardation behaviour of sorbing radionuclides that are relevant to post-closure safety. The ongoing CRR experiment actually investigates the influence of bentonite colloids on the radionuclide transport behaviour through a fractured granitic host rock. Again, the experience in planning and handling of complex tracer field experiments gained in the proceeding experiments will be availed. The methodology adopted for the geological and hydrological characterisation of water-conducting features and the simplification of this characterisation for modelling purposes proved to be indeed effective on the modelling of

Chemical speciation of radionuclides migrating in groundwaters

International Nuclear Information System (INIS)

Robertson, D.; Schilk, A.; Abel, K.; Lepel, E.; Thomas, C.; Pratt, S.; Cooper, E.; Hartwig, P.; Killey, R.

1994-04-01

In order to more accurately predict the rates and mechanisms of radionuclide migration from low-level waste disposal facilities via groundwater transport, ongoing studies are being conducted at field sites at Chalk River Laboratories to identify and characterize the chemical speciation of mobile, long-lived radionuclides migrating in groundwaters. Large-volume water sampling techniques are being utilized to separate and concentrate radionuclides into particular, cationic, anionic, and nonionic chemical forms. Most radionuclides are migrating as soluble, anionic species that appear to be predominantly organoradionuclide complexes. Laboratory studies utilizing anion exchange chromatography have separated several anionically complexed radionuclides, e.g., 60 Co and 106 Ru, into a number of specific compounds or groups of compounds. Further identification of the anionic organoradionuclide complexes is planned utilizing high resolution mass spectrometry. Large-volume ultra-filtration experiments are characterizing the particulate forms of radionuclides being transported in these groundwaters

Radionuclides deposition over Antarctica

International Nuclear Information System (INIS)

Pourchet, M.; Magand, O.; Frezzotti, M.; Ekaykin, A.; Winther, J.-G.

2003-01-01

A detailed and comprehensive map of the distribution patterns for both natural and artificial radionuclides over Antarctica has been established. This work integrates the results of several decades of international programs focusing on the analysis of natural and artificial radionuclides in snow and ice cores from this polar region. The mean value (37±20 Bq m -2 ) of 241 Pu total deposition over 28 stations is determined from the gamma emissions of its daughter 241 Am, presenting a long half-life (432.7 yrs). Detailed profiles and distributions of 241 Pu in ice cores make it possible to clearly distinguish between the atmospheric thermonuclear tests of the fifties and sixties. Strong relationships are also found between radionuclide data ( 137 Cs with respect to 241 Pu and 210 Pb with respect to 137 Cs), make it possible to estimate the total deposition or natural fluxes of these radionuclides. Total deposition of 137 Cs over Antarctica is estimated at 760 TBq, based on results from the 90-180 deg. East sector. Given the irregular distribution of sampling sites, more ice cores and snow samples must be analyzed in other sectors of Antarctica to check the validity of this figure

Colloid-Facilitated Transport of Radionuclides Through The Vadose Zone

International Nuclear Information System (INIS)

Markus Flury; James B. Harsh; John F. McCarthy' Peter C. Lichtner; John M. Zachara

2007-01-01

The main purpose of this project was to advance the basic scientific understanding of colloid and colloid-facilitated Cs transport of radionuclides in the vadose zone. We focused our research on the hydrological and geochemical conditions beneath the leaking waste tanks at the USDOE Hanford reservation. Specific objectives were (1) to determine the lability and thermodynamic stability of colloidal materials, which form after reacting Hanford sediments with simulated Hanford Tank Waste, (2) to characterize the interactions between colloidal particles and contaminants, i.e., Cs and Eu, (3) to determine the potential of Hanford sediments for in situ mobilization of colloids, (4) to evaluate colloid-facilitated radionuclide transport through sediments under unsaturated flow, (5) to implement colloid-facilitated contaminant transport mechanisms into a transport model, and (6) to improve conceptual characterization of colloid-contaminant-soil interactions and colloid-facilitated transport for clean-up procedures and long-term risk assessment

Radionuclides in the food chain

International Nuclear Information System (INIS)

Harley, J.H.; Schmidt, G.D.

1988-01-01

Radionuclides in the Food Chain reviews past experience in meeting the challenge of radionuclide contamination of foodstuffs and water sources and, in the wake of the reactor accidents at Chernobyl and Three Mile Island, presents current concepts and programs relating to measurement, surveillance, effects, risk management, evaluation guidelines, and control and regulatory activities. This volume, based on a symposium sponsored by the International Life Sciences Institute in association with the International Institute for Applied Systems Analysis, which brought together both radiation experts and food industry policymakers, examines such vital topics as structural problems in large-scale crisis-managment systems; dose assessment from man-made sources; international recommendations on radiation protection; airborne contamination, as well as aquatic and soilborne radionuclides; food-chain contamination from testing nuclear devices; long-term health effects of radionuclides in food and water supplies; and use of mathematical models in risk assessment and management. (orig.)

Mobility of Source Zone Heavy Metals and Radionuclides: The Mixed Roles of Fermentative Activity on Fate and Transport of U and Cr. Final Report

Energy Technology Data Exchange (ETDEWEB)

Gerlach, Robin [Montana State Univ., Bozeman, MT (United States); Peyton, Brent M. [Montana State Univ., Bozeman, MT (United States); Apel, William A. [Idaho National Lab., Idaho Falls, ID (United States)

2014-01-29

Various U. S. Department of Energy (DOE) low and medium-level radioactive waste sites contain mixtures of heavy metals, radionuclides and assorted organic materials. In addition, there are numerous sites around the world that are contaminated with a mixture of organic and inorganic contaminants. In most sites, over time, water infiltrates the wastes, and releases metals, radionuclides and other contaminants causing transport into the surrounding environment. We investigated the role of fermentative microorganisms in such sites that may control metal, radionuclide and organics migration from source zones. The project was initiated based on the following overarching hypothesis: Metals, radionuclides and other contaminants can be mobilized by infiltration of water into waste storage sites. Microbial communities of lignocellulose degrading and fermenting microorganisms present in the subsurface of contaminated DOE sites can significantly impact migration by directly reducing and immobilizing metals and radionuclides while degrading complex organic matter to low molecular weight organic compounds. These low molecular weight organic acids and alcohols can increase metal and radionuclide mobility by chelation (i.e., certain organic acids) or decrease mobility by stimulating respiratory metal reducing microorganisms. We demonstrated that fermentative organisms capable of affecting the fate of Cr6+, U6+ and trinitrotoluene can be isolated from organic-rich low level waste sites as well as from less organic rich subsurface environments. The mechanisms, pathways and extent of contaminant transformation depend on a variety of factors related to the type of organisms present, the aqueous chemistry as well as the geochemistry and mineralogy. This work provides observations and quantitative data across multiple scales that identify and predict the coupled effects of fermentative carbon and electron flow on the transport of radionuclides, heavy metals and organic contaminants in

Mobility of Source Zone Heavy Metals and Radionuclides: The Mixed Roles of Fermentative Activity on Fate and Transport of U and Cr. Final Report

International Nuclear Information System (INIS)

Gerlach, Robin; Peyton, Brent M.; Apel, William A.

2014-01-01

Various U. S. Department of Energy (DOE) low and medium-level radioactive waste sites contain mixtures of heavy metals, radionuclides and assorted organic materials. In addition, there are numerous sites around the world that are contaminated with a mixture of organic and inorganic contaminants. In most sites, over time, water infiltrates the wastes, and releases metals, radionuclides and other contaminants causing transport into the surrounding environment. We investigated the role of fermentative microorganisms in such sites that may control metal, radionuclide and organics migration from source zones. The project was initiated based on the following overarching hypothesis: Metals, radionuclides and other contaminants can be mobilized by infiltration of water into waste storage sites. Microbial communities of lignocellulose degrading and fermenting microorganisms present in the subsurface of contaminated DOE sites can significantly impact migration by directly reducing and immobilizing metals and radionuclides while degrading complex organic matter to low molecular weight organic compounds. These low molecular weight organic acids and alcohols can increase metal and radionuclide mobility by chelation (i.e., certain organic acids) or decrease mobility by stimulating respiratory metal reducing microorganisms. We demonstrated that fermentative organisms capable of affecting the fate of Cr6+, U6+ and trinitrotoluene can be isolated from organic-rich low level waste sites as well as from less organic rich subsurface environments. The mechanisms, pathways and extent of contaminant transformation depend on a variety of factors related to the type of organisms present, the aqueous chemistry as well as the geochemistry and mineralogy. This work provides observations and quantitative data across multiple scales that identify and predict the coupled effects of fermentative carbon and electron flow on the transport of radionuclides, heavy metals and organic contaminants in

Concerning initial and secondary character of radionuclide distribution in elementary landscape geochemical systems

Science.gov (United States)

Korobova, Elena; Romanov, Sergey

2017-04-01

Specificity of radionuclide distribution in elementary landscape geochemical systems (ELGS) treated as local system of geochemically linked elementary terrestrial units (in toposequence: watershed-slope-closing depression), belongs to one of the less investigated but practically significant problems of current geochemistry. First measurements after the Chernobyl accident showed a considerable variation of Cs-137 distribution in all examined ELGS (Shcheglov et al, 2001; Romanov, 1989; Korobova, Korovaykov, 1990; Linnik, 2008). The results may be interpreted in frames of two alternative hypotheses: 1) irregularity of the initial contamination; 2) secondary redistribution of the initially regular level of fallout. But herewith only a disproof of the first hypothesis automatically justifies the second one. Factors responsible for initial irregularity of surface contamination included: 1) the presence of the so-called "hot" particles in the initial fallout; 2) interception of radionuclides by forest canopy; 3) irregular aerial particles deposition; 4) uneven initial precipitation. Basing on monitoring Cs-137 spatial distribution that has been performed since 2005, we demonstrate that the observed spatial irregularity in distribution of Cs-137 in ELGS reflects a purely secondary distribution of initial reserves of radionuclides in fallout matter due to its migration with water in local geochemical systems. This statement has some significant consequences. 1. Mechanism of migration of matter in ELGS is complicated and could not be reduced solely to a primitive moving from watershed to closing depression. 2. The control of migration of "labeled atoms" (Cs-137) permits to understand common mechanism of migration of water in all systems on the level of ELGS. 3. Understanding formation of the structure of contamination zones in ELGS permits to use mathematical model to solve the inverse problem of restoration of the initially equable level of their contamination. Performed

Importance of isotopes for understanding the sedimentation processes

International Nuclear Information System (INIS)

Manjunatha, B.R.

2012-01-01

Isotopes of either radioactive or stable depending upon radiation emitted or not respectively which have wide applications in understanding not only the history of sedimentation, but also provide information about paleoclimate. Stable isotope mass difference occurs due to changes in physicochemical conditions of the ambient environment, for instance temperature, evaporation, precipitation, redox processes, and changes in the mobility of elements during weathering processes, biological uptake, metabolism, re-mineralization of biogenic material, etc. In contrast, radionuclides emit radiation because of excess of neutrons present in the nucleus when compared to protons of an atom. The decay of radioactive isotopes is unaffected despite changes in physicochemical variations; hence, they are useful for determining ages of different types of materials on earth. The radioisotopes can be classified based on origin and half life into primordial or long-lived, cosmogenic and artificial radionuclides or fission products. In this study, the importance of 137 Cs artificial radionuclides will be highlighted to understand short-term sedimentation processes, particularly in estuaries, deltas/continental shelf of west coast of India. The distribution of 137 Cs in sediments of south-western continental margin of India indicates that coastal marginal environments are filters or sinks for fall-out radionuclides. The sparse of 137 Cs in the open continental shelf environment indicates that most of sediments are either older or sediments being diluted by components generated in the marine environment

Some parameters of radionuclide kinetics

International Nuclear Information System (INIS)

Prokof'ev, O.N.; Smirnov, V.A.; Belen'kij, E.I.

1978-01-01

Numerical values of the rates of radionuclide absorption into, and elimination from, bovine organs were determined. Kinetic rate constants of radionuclides such as 89 Sr, 99 Mo, 131 I, 132 Tl, and 140 Be were calculated. The calculations were done for muscle, liver, and kidney

Radionuclide - Soil Organic Matter Interactions

DEFF Research Database (Denmark)

Carlsen, Lars

1985-01-01

Interactions between soil organic matter, i.e. humic and fulvic acids, and radionuclides of primary interest to shallow land burial of low activity solid waste have been reviewed and to some extent studied experimentally. The radionuclides considered in the present study comprise cesium, strontium...

Radionuclide transport in a single fissure

International Nuclear Information System (INIS)

Eriksen, T.E.

1984-01-01

Radionuclide migration has been studied in natural fissures running parallel to the axes of granitic drill cores. A short pulse of radionuclide solution was injected at one end of the fissure and the temporal change in radionuclide concentration of the eluate measured. At the end of each experiment the fissure was opened and the radionuclide distribution on the fissure surfaces measured. The retardation of 241 Am(III) at pH 8.2 as well as the variation in 235 Np(V) retardation with pH are found to be in good agreement with K d-values obtained in batch experiments. The reduction of (TcO - 4 ) to Tc(IV) leads as expected to increasing retardation.(author)

SALTSTONE AND RADIONUCLIDE INTERACTIONS: RADIONUCLIDE SORPTION AND DESORPTION, AND SALTSTONE REDUCTION CAPACITY

International Nuclear Information System (INIS)

Kaplan, D; Roberts, Kimberly; Serkiz, Steven; Siegfried, Matthew

2008-01-01

The overall objective of this study was to measure a number of key input parameters quantifying geochemical processes in the subsurface environment of the Savannah River Site's (SRS's) Saltstone Facility. For the first time, sorption (K d ) values of numerous radionuclides were measured with Saltstone and Vault 2 concrete. Particular attention was directed at understanding how Tc adsorbs and desorbs from these cementitious materials with the intent to demonstrate that desorption occurs at a much slower rate than adsorption, thus permitting the use of kinetic terms instead of (or along with) the steady state K d term. Another very important parameter measured was the reduction capacity of these materials. This parameter is used to estimate the duration that the Saltstone facility remains in a reduced chemical state, a condition that maintains several otherwise mobile radionuclides in an immobile form. Key findings of this study follow. K d values for Am, Cd, Ce, Co, Cs, Hg, I, Np, Pa, Pu, Se, Sn, Tc, U, and Y for Saltstone and Vault 2 concrete were measured under oxidized and reduced conditions. Precipitation of several of the higher valence state radionuclides was observed. There was little evidence that the Vault 2 and Saltstone K d values differed from previous SRS K d values measured with reducing grout (Kaplan and Coates 2007). These values also supported a previous finding that K d values of slag-containing cementitious materials, tend to be greater for cations and about the same for anions, than regular cementitious materials without slag. Based on these new findings, it was suggested that all previous reducing concrete K d values be used in future PAs, except Np(V) and Pu(IV) K d values, which should be increased, and I values, which should be slightly decreased in all three stages of concrete aging. The reduction capacity of Saltstone, consisting of 23 wt-% blast furnace slag, was 821.8 microequivalents per gram ((micro)eq/g). This value was approximately

Bioavailability in ecological risk. Assessment for radionuclides

International Nuclear Information System (INIS)

Garnier-Laplace, J.; Gilbin, R.; Della-Vedova, C.; Adam, C.; Simon, O.; Denison, F.; Beaugelin, K.

2005-01-01

The guidance for performing Ecological Risk Assessments (ERA) in Europe has been published in 2003 in the EC's Technical Guidance Document. This document constitutes the official reference in which current water quality standards and risk assessment approach for metals/metalloids are still mainly based on total or dissolved concentrations. However, it has been recognized that accurate assessment of the bio-available metal fraction is crucial, even if the way to incorporate bioavailability into these procedures is still under discussion. The speciation of a pollutant in the exposure medium is the first factor that regulates its bioavailability and consequently its bioaccumulation and the induced biological effects. Therefore, within any ecological risk assessment, bioavailability has obvious implications: firstly in exposure analysis which aim is to determine Predicted Exposure Concentration (PEC); secondly in effect analysis while deriving the so-called Predicted No-Effect Concentrations (PNEC) as toxicity is often linked to the amount of the contaminant incorporated into the tissues of biota. Similarities between metals/metalloids and radionuclides are limited to the biogeochemical behaviour of the element considered and to the need to use bioavailability models. In addition, for radionuclides, emitted ionising radiations (type and energy) need to be taken into account for both exposure and effect analyses whilst performing dosimetric calculations appropriate to the exposure scenarios. A methodology for properly implementing bioavailability models is explained and illustrated for aqueous U(VI), starting from a comprehensive review of the thermodynamic data relevant to environmentally-realistic physico-chemical conditions. Then, the use of thermodynamic equilibrium modelling as a tool for interpreting the bioavailability of U(VI) is presented. Using a systematic approach, different bioavailability models of increasing complexity were tested to model U bio

Radionuclide migration in water reservoirs

International Nuclear Information System (INIS)

Rodionova, L.F.

1983-01-01

Toxicity degree and radiation effect of different radionuclides depend on multiple factors, whose interaction can strengthen or weaken the effects through the mechanism of nuclide accumulation by hydrobiontes. Stage of development of an aquatic organism, its age, mass and sex as well as lifetime and residence time of the organism in the given medium are of importance. The radionuclide build up depends on illumination, locale of the bioobject residence, on the residence nature. The concentration of radionuclides in aquatic organisms and bionts survival depend on a season, temperature of the residence medium, as well as salinity and mineral composition of water influence

Determination of the radionuclide contamination on the Absheron peninsula in Azerbaijan - 59177

International Nuclear Information System (INIS)

Vandergraaf, Tjalle T.; Mamedov, Gudrat G.; Ramazanov, Mahammadali A.; Naghiyev, Jalal A.; Huseynov, Nazim A.; Mehdiyeva, Afat A.

2012-01-01

Much of Azerbaijan's Absheron Peninsula is contaminated by natural U-series and Th-series radionuclides, released in the production of oil and gas and, to a lesser extent, by anthropogenic radionuclides, including Sr-90 and Cs-137, from local industrial activities and trans-border transport. The region contains a large number of pipelines and artificial lagoons that have been used to retain excess groundwater and oil residues. In spite of the long history of the oil and gas industry, radioecological investigations have not been carried out until recently. The purpose of this project is to determine the extent of radionuclide contamination in the Absheron Peninsula using a combination of radiation field measurements and laboratory analyses of selected samples, focusing on ten routes in the vicinity of Baku. The routes were selected as most likely to have become contaminated over time. Soil samples, taken from surface and to a depth of 1 m, aqueous samples from surface waters and marshes, and aqueous and sediment lagoons that showed elevated dosimetry readings, were prepared for gamma spectrometric analysis. Control samples were taken from non-contaminated areas. Samples of air and surface waters were analyzed for Rn-220 and Rn-222. The data will then be used to assess the potential impact of the contamination on the local population. A total slightly 4000 dosimetric readings were taken during the course of this investigation. Of these, 1366 (34%) exceeded 5.4 μR/h. This level is two standard deviations above the mean of the least contaminated route, the 79-km Baku-Guba route. Along the routes Baku-Shemakha and Baku-Guba where no oil and gas activity had taken place, radiation levels of 5.1 ± 1.5 and 4.2 ± 0.6 μR/h, respectively, were obtained. The readings for the route Baku-Guba were then used as representing negligible contamination to which the readings of the other sites were compared. In contrast, along the routes Baku-Lokbatan and Baku-Surakhani, that have

Long lived radionuclides in the environment, in food and in human beings

International Nuclear Information System (INIS)

Fisenne, I.M.

1993-01-01

Our limited knowledge and understanding of the behavior of the naturally occurring radionuclides in the environment, food and man have relied heavily on the skills of radiochemists. The purpose of this document is to lend an appreciation of the role of the radiochemist in programs designed to establish the concentration of uranium, thorium, radium and 210 Pb in a variety of sample matrices. Part I discusses the purposes and strategies for collection of environmental and human tissue samples, chemical and measurement methods, quality assurance and reporting of results. Part II summarizes our present knowledge on the concentrations of Uranium and Thorium Series radionuclides in the environment, diet and man. (author). 183 refs., 11 tabs., 6 figs

New Insights into the Operating Voltage of Aqueous Supercapacitors.

Science.gov (United States)

Yu, Minghao; Lu, Yongzhuang; Zheng, Haibing; Lu, Xihong

2018-03-12

The main limitation of aqueous supercapacitors (SCs) lies in their narrow operating voltages, especially when compared with organic SCs. Fundamental understanding of factors relevant to the operating voltage helps providing guidance for the assembly of high-voltage aqueous SCs. In this regard, this concept analyzes the deciding factors for the operating voltage of aqueous SCs. Strategies applied to expand the operating voltage are summarized and discussed from the aspects of electrolyte, electrode, and asymmetric structure. Dynamic factors associated with water electrolysis and maximally using the available potential ranges of electrodes are particularly emphasized. Finally, other promising approaches that have not been explored and their challenges are also elaborated, hoping to provide more insights for the design of high-voltage aqueous SCs. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Radionuclide Air Emissions Report for 2012

Energy Technology Data Exchange (ETDEWEB)

Wahl, Linnea [Ernest Orlando Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

2013-05-01

Berkeley Lab operates facilities where radionuclides are produced, handled, store d, and potentially emitted . These facilities are subject to the EPA radioactive air emission regulations in 40 CFR 61, Subpart H (EPA 1989a). Radionuclides may be emitted from stacks or vents on buildings where radionuclide production or use is authorized or they may be emitted as diffuse sources. In 2012, all Berkeley Lab sources were minor sources of radionuclides (sources resulting in a potential dose of less than 0.1 mrem/yr [0.001 mSv/yr]) . These minor sources include d about 140 stack sources and no diffuse sources . T here were no unplanned airborne radionuclide emissions from Berkeley Lab operations . Emissions from minor sources were measured by sampling or monitoring or were calculated based on quantities used, received for use, or produced during the year. Using measured and calculated emissions, and building- specific and common parameters, Laboratory personnel applied the EPA -approved computer code s, CAP88-PC and COMPLY , to calculate doses to the maximally exposed individual (MEI) at any offsite point where there is a residence, school, business, or office. Because radionuclides are used at three noncontiguous locations (the main site, Berkeley West Bio center, and Joint BioEnergy Institute), three different MEIs were identified.

Radionuclide Migration through Sediment and Concrete: 16 Years of Investigations

Energy Technology Data Exchange (ETDEWEB)

Golovich, Elizabeth C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mattigod, Shas V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Snyder, Michelle MV [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Powers, Laura [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Whyatt, Greg A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wellman, Dawn M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2014-11-01

The Waste Management Project provides safe, compliant, and cost-effective waste management services for the Hanford Site and the U.S. Department of Energy (DOE) complex. Part of these services includes safe disposal of low-level waste and mixed low-level waste at the Hanford Low-Level Waste Burial Grounds in accordance with the requirements of DOE Order 435.1, Radioactive Waste Management. To partially satisfy these requirements, performance assessment analyses were completed and approved. DOE Order 435.1 also requires continuing data collection to increase confidence in the critical assumptions used in these analyses to characterize the operational features of the disposal facility that are relied on to satisfy the performance objectives identified in the order. Cement-based solidification and stabilization is considered for hazardous waste disposal because it is easily done and cost-efficient. One critical assumption is that concrete will be used as a waste form or container material at the Hanford Site to control and minimize the release of radionuclide constituents in waste into the surrounding environment. Concrete encasement would contain and isolate the waste packages from the hydrologic environment and act as an intrusion barrier. Any failure of concrete encasement may result in water intrusion and consequent mobilization of radionuclides from the waste packages. The radionuclides iodine-129, selenium-75, technetium-99, and uranium-238 have been identified as long-term dose contributors (Mann et al. 2001; Wood et al. 1995). Because of their anionic nature in aqueous solutions, these constituents of potential concern may be released from the encased concrete by mass flow and/or diffusion and migrate into the surrounding subsurface environment (Serne et al. 1989; 1992; 1993a, b; 1995). Therefore, it is necessary to assess the performance of the concrete encasement structure and the ability of the surrounding soil to retard radionuclide migration. Each of the

Radionuclide supply of the progeny via mother's milk

International Nuclear Information System (INIS)

Ovcharenko, E.P.

1982-01-01

While examining transition of radioactive substances from material organism to milk and then radionuclide administration with milk to progeny, a number of relationships had been revealed. They are similar to those discovered by the author during his study on transplacental radionuclide kinetics. The quantity of transition through placental and milk barriers of group 2 Periodical system radionuclides is inversally proportional to radionuclide mass number. There is evidence for the increase of radionuclide transition per different kinds of animal progeny mass unit during pregnancy as well as during lactation [ru

Radionuclide Retention in Concrete Wasteforms

Energy Technology Data Exchange (ETDEWEB)

Bovaird, Chase C.; Jansik, Danielle P.; Wellman, Dawn M.; Wood, Marcus I.

2011-09-30

Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. The information present in the report provides data that (1) measures the effect of concrete wasteform properties likely to influence radionuclide migration; and (2) quantifies the rate of carbonation of concrete materials in a simulated vadose zone repository.

Water, soil, crops and radionuclides. Studies on the behavior of radionuclides in the terrestrial environments

International Nuclear Information System (INIS)

Uchida, Shigeo

2008-01-01

In order to predict the migration of artificially-produced radionuclides into a human body and its radiation dose rates of human body and to decrease the exposed radiation doses of human body, the behavior of radionuclides in the environment must be elucidated. In National Institute of Radiological Sciences (NIRS), the environmental radioecological research group of Nakaminato Laboratory for Marine Radioecology has progressed the survey and research on the behavior of artificially-produced radionuclides in the terrestrial environment. This article describes the research results (the radioactivity of water, soil, and crops) made so far at Nakaminato Laboratory for Marine Radioecology. (M.H.)

Abscess detection with radionuclides

International Nuclear Information System (INIS)

Alavi, J.B.

1988-01-01

Radionuclide studies may aid in the diagnosis and localization of intra-abdominal infections. Despite the introduction of new radiographic and ultrasound methods, there are several clinical situations in which radionuclide scans have proved useful. Those include detection of postoperative intra-abdominal abscess, evaluation of liver abscess, differentiation between pancreatic pseudocyst or abscess, evaluation of fever of unknown origin, and evaluation of inflammatory bowel disease. Each clinical situation is discussed separately here

Sequential extraction procedure for determination of uranium, thorium, radium, lead and polonium radionuclides by alpha spectrometry in environmental samples

Science.gov (United States)

Oliveira, J. M.; Carvalho, F. P.

2006-01-01

A sequential extraction technique was developed and tested for common naturally-occurring radionuclides. This technique allows the extraction and purification of uranium, thorium, radium, lead, and polonium radionuclides from the same sample. Environmental materials such as water, soil, and biological samples can be analyzed for those radionuclides without matrix interferences in the quality of radioelement purification and in the radiochemical yield. The use of isotopic tracers (232U, 229Th, 224Ra, 209Po, and stable lead carrier) added to the sample in the beginning of the chemical procedure, enables an accurate control of the radiochemical yield for each radioelement. The ion extraction procedure, applied after either complete dissolution of the solid sample with mineral acids or co-precipitation of dissolved radionuclide with MnO2 for aqueous samples, includes the use of commercially available pre-packed columns from Eichrom® and ion exchange columns packed with Bio-Rad resins, in altogether three chromatography columns. All radioactive elements but one are purified and electroplated on stainless steel discs. Polonium is spontaneously plated on a silver disc. The discs are measured using high resolution silicon surface barrier detectors. 210Pb, a beta emitter, can be measured either through the beta emission of 210Bi, or stored for a few months and determined by alpha spectrometry through the in-growth of 210Po. This sequential extraction chromatography technique was tested and validated with the analysis of certified reference materials from the IAEA. Reproducibility was tested through repeated analysis of the same homogeneous material (water sample).

Secondary Uranium-Phase Paragenesis and Incorporation of Radionuclides into Secondary Phase

Energy Technology Data Exchange (ETDEWEB)

R. Finch

2001-06-05

The purpose of this analysis/model report (AMR) is to assess the potential for uranium (U) (VI) compounds, formed during the oxidative corrosion of spent uranium-oxide (UO{sub 2}) fuels, to sequester certain radionuclides and, thereby, limit their release. The ''unsaturated drip tests'' being conducted at Argonne National Laboratory (ANL) provide the basis of this AMR (Table 1). The ANL drip tests on spent fuel are the only experiments on fuel corrosion from which solids have been analyzed for trace levels of radionuclides. Brief summaries are provided of the results from other selected corrosion and dissolution experiments on spent UO{sub 2} fuels, specifically those conducted under nominally oxidizing conditions. Discussions of the current understanding of thermodynamic and kinetic properties of U(VI) compounds is provided in order to outline the scientific basis for modeling precipitation and dissolution of potential radionuclide-bearing phases under repository-relevant conditions. Attachment I provides additional information on corrosion mechanisms and behaviors of radionuclides in the tests at ANL. Attachment II reviews occurrence, formation, and alteration (collectively known as paragenesis) of naturally occurring U(VI) minerals because natural mineral occurrences can be used to assess the possible long-term behaviors of U(VI) compounds formed in short-term laboratory experiments and to extrapolate experimental results to repository-relevant time scales. This AMR develops a model for calculating dissolved concentrations of radionuclides that are incorporated into U(VI) compounds, which is an alternative to models currently used in TSPA to calculate dissolved concentration limits for certain radionuclides. In particular, the model developed in this AMR applies to Np (neptunium) concentrations being controlled by solid uranyl oxyhydroxides that are known to contain trace levels of Np. The results of this AMR and the conceptual model

Secondary Uranium-Phase Paragenesis and Incorporation of Radionuclides into Secondary Phases

International Nuclear Information System (INIS)

Finch, R.

2001-01-01

The purpose of this analysis/model report (AMR) is to assess the potential for uranium (U) (VI) compounds, formed during the oxidative corrosion of spent uranium-oxide (UO 2 ) fuels, to sequester certain radionuclides and, thereby, limit their release. The ''unsaturated drip tests'' being conducted at Argonne National Laboratory (ANL) provide the basis of this AMR (Table 1). The ANL drip tests on spent fuel are the only experiments on fuel corrosion from which solids have been analyzed for trace levels of radionuclides. Brief summaries are provided of the results from other selected corrosion and dissolution experiments on spent UO 2 fuels, specifically those conducted under nominally oxidizing conditions. Discussions of the current understanding of thermodynamic and kinetic properties of U(VI) compounds is provided in order to outline the scientific basis for modeling precipitation and dissolution of potential radionuclide-bearing phases under repository-relevant conditions. Attachment I provides additional information on corrosion mechanisms and behaviors of radionuclides in the tests at ANL. Attachment II reviews occurrence, formation, and alteration (collectively known as paragenesis) of naturally occurring U(VI) minerals because natural mineral occurrences can be used to assess the possible long-term behaviors of U(VI) compounds formed in short-term laboratory experiments and to extrapolate experimental results to repository-relevant time scales. This AMR develops a model for calculating dissolved concentrations of radionuclides that are incorporated into U(VI) compounds, which is an alternative to models currently used in TSPA to calculate dissolved concentration limits for certain radionuclides. In particular, the model developed in this AMR applies to Np (neptunium) concentrations being controlled by solid uranyl oxyhydroxides that are known to contain trace levels of Np. The results of this AMR and the conceptual model developed from it and presented in

Therapy for incorporated radionuclides: scope and need

International Nuclear Information System (INIS)

Smith, V.H.

1981-03-01

In the United States the recent termination of funding for research on therapy for incorporated radionuclides has virtually halted progress on improved or new agents and procedures for removing radioactivity from the body. Research was eliminated, but is still needed on new removal agents, improved delivery system, in vitro test systems, and the toxicology of treatments. For many radionuclides, no adequate therapy exists. The relationship between radionuclide removal and reduction in cancer risk is still unanswered. Without proper research support, needed improvements in the treatment for incorporated radionuclides in the US are uncertain

Phytoremediation of soils contaminated with radionuclides

International Nuclear Information System (INIS)

Yamaguchi, Isamu

2004-01-01

Aiming at efficient phytoremediation of soils contaminated with radionuclides, we examined the effect of soil microbes on the uptake ability of plants using the multitracer technique to find that tomato rhizofungi in Fusarium spp. can stimulate the uptake of 85 Sr and 137 Cs by the plants. The synergic effect of a nonpathogenic strain of F. oxysporum on the uptake of radionuclides by plants proved to be enhanced by introducing a phytochelatin synthase gene into the fungus. Since soil contamination by radionuclides is still an unsolved problem in many parts of the world. Studies on phytoremediation of polluted soil environment will be important for developing effective strategies and devising adequate techniques to reduce human risks caused by food contamination of radionuclides. (author)

MARFA version 3.2.2 user's manual: migration analysis of radionuclides in the far field

Energy Technology Data Exchange (ETDEWEB)

Painter, Scott; Mancillas, James (Center for Nuclear Waste Regulatory Analyses, Southwest Research Inst., San Antonio, TX (United States))

2009-12-15

concentration. Nonlinear processes such as solubility-limited transport or aqueous speciation are not represented. The MARFA code is specifically designed to work with output from discrete fracture network (DFN), continuous porous medium (CPM), or nested DFN/CPM flow models. Transport is assumed to occur along a set of trajectories or pathways that originate at radionuclide source locations. Trajectories are intended to represent the movement of hypothetical, advectively transported groundwater tracers and are typically calculated by pathline tracing in a DFN or DFN/CPM flow code. MARFA supports an arbitrary number of trajectories and source locations

National Low-Level Waste Management Program Radionuclide Report Series

International Nuclear Information System (INIS)

Rudin, M.J.; Garcia, R.S.

1992-02-01

This volume serves as an introduction to the National Low-Level Radioactive Waste Management Program Radionuclide Report Series. This report includes discussions of radionuclides listed in Title 10 of the Code of Federal Regulations Part 61.55, Tables 1 and 2 (including alpha-emitting transuranics with half-lives greater than five years). Each report includes information regarding radiological and chemical characteristics of specific radionuclides. Information is also included discussing waste streams and waste forms that may contain each radionuclide, and radionuclide behavior in the environment and in the human body. Not all radionuclides commonly found at low-level radioactive waste sites are included in this report. The discussion in this volume explains the rationale of the radionuclide selection process

Radionuclide Retention in Concrete Waste Forms

Energy Technology Data Exchange (ETDEWEB)

Mattigod, Shas V.; Bovaird, Chase C.; Wellman, Dawn M.; Wood, Marcus I.

2010-09-30

Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how waste form performance is affected by the full range of environmental conditions within the disposal facility; the process of waste form aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of waste form aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the waste forms come in contact with groundwater. The information presented in the report provides data that 1) quantify radionuclide retention within concrete waste form materials similar to those used to encapsulate waste in the Low-Level Waste Burial Grounds (LLBG); 2) measure the effect of concrete waste form properties likely to influence radionuclide migration; and 3) quantify the stability of uranium-bearing solid phases of limited solubility in concrete.

Recent developments in the integrated approach toward characterization of radionuclide transport, Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Simmons, A.M.; Canepa, J.A.

1992-01-01

The radionuclide migration program for the Yucca Mountain Site Characterization Project (YMP) includes studies of radionuclide solubility, sorption, diffusion, and transport. The study plans incorporate all possible parameters of investigation; decision-making strategies for prioritizing the parameters and evaluating their significance were developed in conjunction with the study plans. After definition of explicit research goals for each study, YMP evaluated the applicability of existing data and formulated experimental approaches for obtaining additional data. This resulted in development of individual testing strategies that were integrated into an overall strategy for the radionuclide migration program designed to provide input to credible performance assessments. The strategies allow for decision points at various steps of data collection and testing. They provide a streamlined process toward a defensible level of understanding of chemical retardation and transport processes that will be used to predict the mountain's ability to isolate waste. (author)

Radionuclide injury to the lung

International Nuclear Information System (INIS)

Dagle, G.E.; Sanders, C.L.

1984-01-01

Radionuclide injury to the lung has been studied in rats, hamsters, dogs, mice and baboons. Exposure of the lung to high dose levels of radionuclides produces a spectrum of progressively more severe functional and morphological changes, ranging from radiation pneumonitis and fibrosis to lung tumors. These changes are somewhat similar for different species. Their severity can be related to the absorbed radiation dose (measured in rads) produced by alpha, beta or gamma radiation emanating from various deposited radionuclides. The chemicophysical forms of radionuclides and spatial-temporal factors are also important variables. As with other forms of injury to the lung, repair attempts are highlighted by fibrosis and proliferation of pulmonary epithelium. Lung tumors are the principal late effect observed in experimental animals following pulmonary deposition of radionuclides at dose levels that do not result in early deaths from radiation pneumonitis or fibrosis. The predominant lung tumors described have been of epithelial origin and have been classified, in decreasing frequency of occurrence, as adenocarcinoma, bronchioloalveolar carcinoma, epidermoid carcinomas and combined epidermoid and adenocarcinoma. Mesothelioma and fibrosarcoma have been observed in rats, but less commonly in other species. Hemangiosarcomas were frequently observed in dogs exposed to beta-gamma emitters, and occasionally in rats exposed to alpha emitters. These morphologic changes in the lungs of experimental animals were reviewed and issues relevant to the prediction of human hazards discussed. 88 references

The vertical distribution of radionuclides in a Ribble Estuary saltmarsh: transport and deposition of radionuclides

International Nuclear Information System (INIS)

Brown, J.E.; McDonald, P.; Parker, A.; Rae, J.E.

1999-01-01

Routine discharges of low-level liquid radioactive waste by British Nuclear Fuels plc (BNFL) at Sellafield and Springfields have resulted in enhanced levels of radionuclides in sediments of the Ribble Estuary, NW England, UK. Variations in radionuclide concentrations ( 137 Cs, 230 Th, and 239240 Pu) with depth in a mature saltmarsh core were analysed in order to investigate historical discharge trends and waste-dispersal mechanisms. Core samples from Longton/Hutton Marsh were analysed by gamma-spectrometry and α-spectrometry for radionuclides and by laser granulometry to establish grain-size variations with depth. Distinct subsurface maxima were present for 137 Cs and 239240 Pu with activities as high as 4500 Bq kg -1 for 137 Cs and 600 Bq kg -1 for 239240 Pu. Thorium-230 exhibited complex activity profiles with depth, specific activities ranging between 200 and 2400 Bq kg -1 . The vertical distributions of Sellafield-derived radionuclides ( 137 Cs and 239240 Pu) in mature saltmarsh deposits reflect the time-integrated discharge pattern from Sellafield, implying a transport mechanism that has involved the mixing of sediment labelled with radioactivity from recent discharges and sediment labelled from historical discharge events before deposition. A mechanism involving the transport of contaminated silt therefore seems to dominate. The vertical distribution of Springfields-derived 230 Th in the same areas reflects the annual gross-α discharge pattern from BNFL Springfields. In contrast to the Sellafield-derived radionuclides, a fairly rapid transport mechanism from source to sink is implied, with little or no time for mixing with radionuclides discharged years earlier. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

Diffusion coefficients of paracetamol in aqueous solutions

International Nuclear Information System (INIS)

Ribeiro, Ana C.F.; Barros, Marisa C.F.; Veríssimo, Luís M.P.; Santos, Cecilia I.A.V.; Cabral, Ana M.T.D.P.V.; Gaspar, Gualter D.; Esteso, Miguel A.

2012-01-01

Highlights: ► Mutual diffusion coefficients of paracetamol in aqueous dilute solutions. ► Influence of the thermodynamic factors on the variation of their mutual diffusion coefficients. ► Estimation of the mutual limiting diffusion coefficients of the molecular, D m 0 , and ionized forms, D ± 0 , of this drug. - Abstract: Binary mutual diffusion coefficients measured by the Taylor dispersion method, for aqueous solutions of paracetamol (PA) at concentrations from (0.001 to 0.050) mol·dm −3 at T = 298.15 K, are reported. From the Nernst–Hartley equation and our experimental results, the limiting diffusion coefficient of this drug and its thermodynamic factors are estimated, thereby contributing in this way to a better understanding of the structure of such systems and of their thermodynamic behaviour in aqueous solution at different concentrations.

Radiation-Induced Second Cancer Risk Estimates From Radionuclide Therapy

Science.gov (United States)

Bednarz, Bryan; Besemer, Abigail

2017-09-01

The use of radionuclide therapy in the clinical setting is expected to increase significantly over the next decade. There is an important need to understand the radiation-induced second cancer risk associated with these procedures. In this study the radiation-induced cancer risk in five radionuclide therapy patients was investigated. These patients underwent serial SPECT imaging scans following injection as part of a clinical trial testing the efficacy of a 131Iodine-labeled radiopharmaceutical. Using these datasets the committed absorbed doses to multiple sensitive structures were calculated using RAPID, which is a novel Monte Carlo-based 3D dosimetry platform developed for personalized dosimetry. The excess relative risk (ERR) for radiation-induced cancer in these structures was then derived from these dose estimates following the recommendations set forth in the BEIR VII report. The radiation-induced leukemia ERR was highest among all sites considered reaching a maximum value of approximately 4.5. The radiation-induced cancer risk in the kidneys, liver and spleen ranged between 0.3 and 1.3. The lifetime attributable risks (LARs) were also calculated, which ranged from 30 to 1700 cancers per 100,000 persons and were highest for leukemia and the liver for both males and females followed by radiation-induced spleen and kidney cancer. The risks associated with radionuclide therapy are similar to the risk associated with external beam radiation therapy.

Interpretation of biological-rate coefficients derived from radionuclide content, radionuclide concentration and specific activity experiments

International Nuclear Information System (INIS)

Vanderploeg, H.A.; Booth, R.S.

1976-01-01

Rigorous expressions are derived for the biological-rate coefficients (BRCs) determined from time-dependent measurements of three different dependent variables of radionuclide tracer experiments. These variables, which apply to a single organism, are radionuclide content, radionuclide concentration and specific activity. The BRCs derived from these variables have different mathematical expressions and, for high growth rates, their numerical values can be quite different. The precise mathematical expressions for the BRCs are presented here to aid modelers in selecting the correct parameters for their models and to aid experiments in interpreting their results. The usefulness of these three variables in quantifying elemental uptakes and losses by organisms is discussed. (U.K.)

Research on sorption behavior of radionuclides under shallow land environment. Mechanism and standard methodologies for measurement of distribution coefficients of radionuclides

International Nuclear Information System (INIS)

Sakamoto, Yoshiaki; Tanaka, Tadao; Takebe, Shinichi; Nagao, Seiya; Ogawa, Hiromichi; Komiya, Tomokazu; Hagiwara, Shigeru

2001-01-01

This study consists of two categories' research works. One is research on sorption mechanism of radionuclides with long half-life, which are Technetium-99, TRU elements and U series radionuclides, on soil and rocks, including a development of database of distribution coefficients of radionuclides. The database on the distribution coefficients of radionuclides with information about measurement conditions, such as shaking method, soil characteristics and solution composition, has been already opened to the public (JAERI-DATABASE 20001003). Another study is investigation on a standard methodology of the distribution coefficient of radionuclide on soils, rocks and engineering materials in Japan. (author)

Radionuclide interactions with marine sediments

International Nuclear Information System (INIS)

Higgo, J.J.W.

1987-09-01

A critical review of the literature on the subject of the interactions of radionuclides with marine sediments has been carried out. On the basis of the information available, an attempt has been made to give ranges and 'best estimates' for the distribution ratios between seawater and sediments. These estimates have been based on an understanding of the sediment seawater system and the porewater chemistry and mineralogy. Field measurements, laboratory measurements and estimates based on stable-element geochemical data are all taken into account. Laboratory measurements include distribution-ratio and diffusion-coefficient determinations. The elements reviewed are carbon, chlorine, calcium, nickel, selenium, strontium, zirconium, niobium, technetium, tin, iodine, caesium, lead, radium, actinium, thorium, protactinium, uranium, neptunium, plutonium, americium and curium. (author)

Aqueous solutions of ionic liquids: microscopic assembly

NARCIS (Netherlands)

Vicent-Luna, J.M.; Dubbeldam, D.; Gómez-Álvarez, P.; Calero, S.

2016-01-01

Aqueous solutions of ionic liquids are of special interest, due to the distinctive properties of ionic liquids, in particular, their amphiphilic character. A better understanding of the structure-property relationships of such systems is hence desirable. One of the crucial molecular-level

RIVER-RAD, Radionuclide Transport in Surface Waters

International Nuclear Information System (INIS)

1996-01-01

1 - Description of program or function: RIVER-RAD assesses the potential fate of radionuclides released to rivers. The model is simplified in nature and is intended to provide guidance in determining the potential importance of the surface water pathway, relevant transport mechanisms, and key radionuclides in estimating radiological dose to man. 2 - Method of solution: A compartmental linear transfer model is used in RIVER-RAD. The river system model in the code is divided into reaches (compartments) of equal size, each with a sediment compartment below it. The movement of radionuclides is represented by a series of transfers between the reaches, and between the water and sediment compartments of each reach. Within each reach (for both the water and sediment compartments), the radionuclides are assumed to be uniformly mixed. Upward volatilization is allowed from the water compartment, and the transfer of radionuclides between the reaches is determined by the flow rate of the river. Settling and resuspension velocities determine the transfer of absorbed radionuclides between the water and sediment compartments. Radioactive decay and decay-product buildup are incorporated into all transport calculations for all radionuclide chains specified by the user. Each nuclide may have unique input and removal rates. Volatilization and radiological decay are considered as linear rate constants in the model. 3 - Restrictions on the complexity of the problem: None noted

EBS Radionuclide Transport Abstraction

International Nuclear Information System (INIS)

Schreiner, R.

2001-01-01

The purpose of this work is to develop the Engineered Barrier System (EBS) radionuclide transport abstraction model, as directed by a written development plan (CRWMS M and O 1999a). This abstraction is the conceptual model that will be used to determine the rate of release of radionuclides from the EBS to the unsaturated zone (UZ) in the total system performance assessment-license application (TSPA-LA). In particular, this model will be used to quantify the time-dependent radionuclide releases from a failed waste package (WP) and their subsequent transport through the EBS to the emplacement drift wall/UZ interface. The development of this conceptual model will allow Performance Assessment Operations (PAO) and its Engineered Barrier Performance Department to provide a more detailed and complete EBS flow and transport abstraction. The results from this conceptual model will allow PA0 to address portions of the key technical issues (KTIs) presented in three NRC Issue Resolution Status Reports (IRSRs): (1) the Evolution of the Near-Field Environment (ENFE), Revision 2 (NRC 1999a), (2) the Container Life and Source Term (CLST), Revision 2 (NRC 1999b), and (3) the Thermal Effects on Flow (TEF), Revision 1 (NRC 1998). The conceptual model for flow and transport in the EBS will be referred to as the ''EBS RT Abstraction'' in this analysis/modeling report (AMR). The scope of this abstraction and report is limited to flow and transport processes. More specifically, this AMR does not discuss elements of the TSPA-SR and TSPA-LA that relate to the EBS but are discussed in other AMRs. These elements include corrosion processes, radionuclide solubility limits, waste form dissolution rates and concentrations of colloidal particles that are generally represented as boundary conditions or input parameters for the EBS RT Abstraction. In effect, this AMR provides the algorithms for transporting radionuclides using the flow geometry and radionuclide concentrations determined by other

Radionuclide carrier

International Nuclear Information System (INIS)

Hartman, F.A.; Kretschmar, H.C.; Tofe, A.J.

1978-01-01

A physiologically acceptable particulate radionuclide carrier is described. It comprises a modified anionic starch derivative with 0.1% to 1.5% by weight of a reducing agent and 1 to 20% by weight of anionic substituents

Chapter 13. Radionuclides in medicine

International Nuclear Information System (INIS)

Toelgyessy, J.; Harangozo, M.

2000-01-01

This is a chapter of textbook of radioecology for university students. In this chapter authors deal with problems connected with using of radionuclides in medicine. Methods of treatment with using of radionuclides are reviewed. Chapter consists of next parts: (1) Remotion of thyroid gland; (2) Treatment of cerebrally tumour in nuclear reactor; (3) Artificial heart

Naturally occurring radionuclides in food

International Nuclear Information System (INIS)

Djujic, I.

1995-01-01

The naturally occurring radionuclides are the major source of radiation exposure to humans. The principal way of natural radiation exposure is the inhalation of 222 Rn decay products (about 85% of the total). The remainder is equally divided between internally deposited radionuclides, cosmic and terrestrial sources. In the present study, the content of 40 K, 210 Pb, 226 Ra, 230 Th, 232 Th and 238 U in representative food samples (milk, pork, beef, potatoes, wheat and corn flour) and samples of different food items that do not represent entire national production but provide interesting additional data for approximative calculation of naturally occurring radionuclide intake is presented. Daily weight of food eaten, participation of food groups, as well as daily intake by food of mentioned naturally occurring radionuclides in the Serbian diet was obtained on the base of house hold budget surveys. The result obtained for daily intake estimates in mBq for Serbian population are 78.1 ( 40 K), 38.2( 210 Pb), 52.3( 226 Ra), 2.0( 230 Th) and 12.5( 238 U). (author)

Radionuclide Sensors for Subsurface Water Monitoring. Final report

International Nuclear Information System (INIS)

Timothy DeVol

2006-01-01

Contamination of the subsurface by radionuclides is a persistent and vexing problem for the Department of Energy. These radionuclides must be measured in field studies and monitored in the long term when they cannot be removed. However, no radionuclide sensors existed for groundwater monitoring prior to this team's research under the EMSP program. Detection of a and b decays from radionuclides in water is difficult due to their short ranges in condensed media

Determination of natural occurring radionuclides concentrations

International Nuclear Information System (INIS)

Stajic, J.; Markovic, V.; Krstic, D.; Nikezic, D.

2011-01-01

Tobacco smoke contains certain concentrations of naturally occurring radionuclides from radioactive chains of uranium and thorium - 214 Pb, 214 Bi, 228 Ac, 208 Tl, 226 Ra, 232 Th and 40 K. Inhaling of tobacco smoke leads to internal exposure of man. In order to estimate absorbed dose of irradiation it is necessary to determine concentrations of radionuclides present in the tobacco leaves. In this paper specific activities of naturally occurring radionuclides were measured in tobacco samples from cigarettes which are used in Serbia. [sr

Manual of bioassay procedures for radionuclides

International Nuclear Information System (INIS)

Pleskach, S.; Petkau, A.

1986-06-01

A monitoring program is described by which atomic radiation workers ar monitored for internal contamination with radionuclides in the workplace. The program involves analytical procedures for measuring alpha, beta and gamma activity in biological specimens, usually urine. Radionuclides are identified by their characteristic radiation using liquid scintillation counting, and alpha, beta and gamma spectrometry. Examples of calculating the minimum detectable activity for specific radionuclides are given and used to derive call-in-criteria in accordance with which the different groups of workers are monitored each month

Interaction of radionuclides with geomedia associated with the Waste Isolation Pilot Plant (WIPP) site in New Mexico

International Nuclear Information System (INIS)

Dosch, R.G.; Lynch, A.W.

1978-06-01

A survey of the potential of geological media from the vicinity of the Waste Isolation Pilot Plant site in Southeastern New Mexico for retardation of radionuclide migration in an aqueous carrier was conducted. The survey included the measurement of sorption coefficients (Kd) for twelve radionuclides between three natural water simulants and ten samples from various geological strata. The nuclides included 137 Cs, 85 Sr, 131 I, 99 Tc, 125 Sb, 144 Ce, 152 Eu, 153 Gd, 106 Ru, 243 Am, 244 Cm, and 238 Pu. The compositions of the simulant solutions were those expected of water in contact with potash minerals or halite deposits in the area and in a typical groundwater found in the Delaware Basin. The geological samples were obtained from potential aquifers above and below the proposed repository horizons and from bedded salt deposits in the repository horizons. In brine solutions, Tc and I were not significantly adsorbed by any of the minerals and Cs and Sr showed minimal adsorption (Kd's 10 3 and Ru and Sb Kd's varied in the range of 25 to > 10 3 . In the groundwater simulant, Tc and I showed the same behavior, but the Kd's of the other nuclides were generally higher. Some initial parametric studies involving pH, trace organic constituents in the simulant solutions, and radionuclide concentrations were carried out. Significant differences in the observed Kd's can result from varying one or more of these solution parameters

Radionuclides in ground-level air

International Nuclear Information System (INIS)

Sinkko, K.

1987-01-01

In the air surveillance programme the concentrations of artificial radionuclides are monitored in the air close to the ground to obtain the necessary basic data for estimating the exposure of the Finnish population to fall-out radionuclides and also to detect atmospheric traces of radioactive materials caused by their use or production. Airborne dust is collected on filters with high-volume air samplers and the concentrations of gamma-emitting radionuclides in the air are evaluated. In the first quarter of 1986 only long-lived cesium, caused by earlier atmospheric nuclear explosions was detected. The concentrations of cesium were very low. In January and March a small amount of short-lived, fresh fission and activation products were also observed

Radionuclide transport in the repository near-field and far-field

International Nuclear Information System (INIS)

Poteri, A.; Nordman, H.; Pulkkanen, V.-M.; Smith, P.

2014-01-01

above are supplemented by a number of complementary cases that aim to develop a better understanding of the modelled system or subsystems. Far-field modelling has not needed to be carried out for all complementary calculation cases. The selection of cautious locations for the analysed defective canister in the base scenario is supported by modelling calculation cases where all potential canister locations for the defective canister are considered. A thorough analysis of the results from the calculation cases is carried out in the Assessment of Radionuclide Release Scenarios report. The present report includes a couple of extensions of the main calculation cases that are not directly discussed in the Assessment of Radionuclide Release Scenarios report. These include analysis that illustrates influence of the stochastic variability on the selection of the cautious canister location and influence of the longitudinal dispersion on the release rates. The selected cautious canister location gives very pessimistic geosphere retention properties relative to the distributions of the transport properties from the analysed alternative DFN models and realisations. The influence on the release rates of the dominating nuclides caused by the longitudinal dispersion and realisation of the transport classes along the geosphere release path appears to be negligible. (orig.)

Selected radionuclides important to low-level radioactive waste management

International Nuclear Information System (INIS)

1996-11-01

The purpose of this document is to provide information to state representatives and developers of low level radioactive waste (LLW) management facilities about the radiological, chemical, and physical characteristics of selected radionuclides and their behavior in the environment. Extensive surveys of available literature provided information for this report. Certain radionuclides may contribute significantly to the dose estimated during a radiological performance assessment analysis of an LLW disposal facility. Among these are the radionuclides listed in Title 10 of the Code of Federal Regulations Part 61.55, Tables 1 and 2 (including alpha emitting transuranics with half-lives greater than 5 years). This report discusses these radionuclides and other radionuclides that may be significant during a radiological performance assessment analysis of an LLW disposal facility. This report not only includes essential information on each radionuclide, but also incorporates waste and disposal information on the radionuclide, and behavior of the radionuclide in the environment and in the human body. Radionuclides addressed in this document include technetium-99, carbon-14, iodine-129, tritium, cesium-137, strontium-90, nickel-59, plutonium-241, nickel-63, niobium-94, cobalt-60, curium -42, americium-241, uranium-238, and neptunium-237

Selected radionuclides important to low-level radioactive waste management

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-11-01

The purpose of this document is to provide information to state representatives and developers of low level radioactive waste (LLW) management facilities about the radiological, chemical, and physical characteristics of selected radionuclides and their behavior in the environment. Extensive surveys of available literature provided information for this report. Certain radionuclides may contribute significantly to the dose estimated during a radiological performance assessment analysis of an LLW disposal facility. Among these are the radionuclides listed in Title 10 of the Code of Federal Regulations Part 61.55, Tables 1 and 2 (including alpha emitting transuranics with half-lives greater than 5 years). This report discusses these radionuclides and other radionuclides that may be significant during a radiological performance assessment analysis of an LLW disposal facility. This report not only includes essential information on each radionuclide, but also incorporates waste and disposal information on the radionuclide, and behavior of the radionuclide in the environment and in the human body. Radionuclides addressed in this document include technetium-99, carbon-14, iodine-129, tritium, cesium-137, strontium-90, nickel-59, plutonium-241, nickel-63, niobium-94, cobalt-60, curium -42, americium-241, uranium-238, and neptunium-237.

Determination of sorption mechanisms of radionuclides onto clay minerals using extended x-ray absorption fine structure (EXAFS) spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Daehn, R.; Scheidegger, A.; Baeyens, B.; Bradbury, M.H

2001-03-01

Much of the experimental work in the Waste Management Laboratory at PSI concentrates on trying to understand the processes and mechanisms which govern the release of safety-relevant radionuclides from waste matrices, and their transport through engineered barrier systems and the surrounding geosphere. For this reason, detailed sorption studies of radionuclides (Cs, Sr, Ni, Zn, Eu, Am, Th and Se) in clay and cement systems are being conducted. The sorption and modelling studies are combined with kinetic investigations and advanced spectroscopic and microscopic methods in order to understand the sorption mechanism on an atomic level. This approach is part of a new multidisciplinary research field called Molecular Environmental Science (MES). In this paper, a case study of Ni sorption on montmorillonite is presented to illustrate how EXAFS can be used successfully to better understand sorption processes. (author)

Determination of sorption mechanisms of radionuclides onto clay minerals using extended x-ray absorption fine structure (EXAFS) spectroscopy

International Nuclear Information System (INIS)

Daehn, R.; Scheidegger, A.; Baeyens, B.; Bradbury, M.H.

2001-01-01

Much of the experimental work in the Waste Management Laboratory at PSI concentrates on trying to understand the processes and mechanisms which govern the release of safety-relevant radionuclides from waste matrices, and their transport through engineered barrier systems and the surrounding geosphere. For this reason, detailed sorption studies of radionuclides (Cs, Sr, Ni, Zn, Eu, Am, Th and Se) in clay and cement systems are being conducted. The sorption and modelling studies are combined with kinetic investigations and advanced spectroscopic and microscopic methods in order to understand the sorption mechanism on an atomic level. This approach is part of a new multidisciplinary research field called Molecular Environmental Science (MES). In this paper, a case study of Ni sorption on montmorillonite is presented to illustrate how EXAFS can be used successfully to better understand sorption processes. (author)

Measurements for modeling radionuclide transfer in the aquatic environment

International Nuclear Information System (INIS)

Kahn, B.

1976-01-01

Analytical methods for measuring radionuclides in the aquatic environment are discussed for samples of fresh water and seawater, fish and shellfish, biota such as algae, plankton, seaweed, and aquatic plants, and sediment. Consideration is given to radionuclide collection and concentration, sample preservation, radiochemical and instrumental analysis, and quality assurance. Major problems are the very low environmental levels of the radionuclides of interest, simultaneous occurrence of radionuclides in several chemical and physical forms and the numerous factors that affect radionuclide levels in and transfers among media. Some radionuclides of importance in liquid effluents from nuclear power stations are listed, and sources of radiochemical analytical methods are recommended

Accumulation of radionuclides by lichen symbionts

Energy Technology Data Exchange (ETDEWEB)

Nifontova, M G; Kulikov, N V [AN SSSR, Sverdlovsk. Inst. Ehkologii Rastenij i Zhivotnykh

1983-01-01

The aim of investigation is the quantitative estimation of ability and role of separate symbionts in the accumulation of radionuclides. As investigation volumes, durably cultivated green lichen alga Trebouxia erici and lichen fungi extracted from Cladonia rangiferina, Parmelia caperata and Acarospora fuscata are used. The accumulation of radioactive isotopes with fungi and seaweeds is estimated according to accumulation coefficients (AC) which are the ratio of radiation concentration in plants and agarized medium. Radionuclide content (/sup 90/Sr and /sup 137/Cs) is determined radiometrically. A special series of experiments is done to investigate radionuclide accumulation dependences with lichen seaweed and fungi on light conditions. It is shown that both symbionts of lichen-seaweed and fungus take part in the accumulation of radionuclide from outer medium (atmospheric fall-out and soil). However fungus component constituting the base of structural organization of thallus provides the greater part of radionuclides accumulated by the plant. Along with this the violation of viability of seaweed symbionts particularly in the case of light deficiency brings about the reduction of /sup 137/Cs sorption by seaweeds and tells on the total content of radiocesium in plant thallus.

Targeted Radionuclide Therapy

Directory of Open Access Journals (Sweden)

David Cheng

2011-10-01

Full Text Available Targeted radiotherapy is an evolving and promising modality of cancer treatment. The killing of cancer cells is achieved with the use of biological vectors and appropriate radionuclides. Among the many advantages of this approach are its selectiveness in delivering the radiation to the target, relatively less severe and infrequent side effects, and the possibility of assessing the uptake by the tumor prior to the therapy. Several different radiopharmaceuticals are currently being used by various administration routes and targeting mechanisms. This article aims to briefly review the current status of targeted radiotherapy as well as to outline the advantages and disadvantages of radionuclides used for this purpose.

Targeted Radionuclide Therapy

Energy Technology Data Exchange (ETDEWEB)

Ersahin, Devrim, E-mail: devrimersahin@yahoo.com; Doddamane, Indukala; Cheng, David [Department of Diagnostic Radiology, School of Medicine, Yale University, 333 Cedar St., New Haven, CT 06520 (United States)

2011-10-11

Targeted radiotherapy is an evolving and promising modality of cancer treatment. The killing of cancer cells is achieved with the use of biological vectors and appropriate radionuclides. Among the many advantages of this approach are its selectiveness in delivering the radiation to the target, relatively less severe and infrequent side effects, and the possibility of assessing the uptake by the tumor prior to the therapy. Several different radiopharmaceuticals are currently being used by various administration routes and targeting mechanisms. This article aims to briefly review the current status of targeted radiotherapy as well as to outline the advantages and disadvantages of radionuclides used for this purpose.

Radionuclides in foods

International Nuclear Information System (INIS)

1994-01-01

This report contains data on the levels of radionuclides in the UK foodchain. Most data derive from monitoring programmes that exist around nuclear sites, and in some cases date back to the 1960s. Some comparative data from site operator and government-run programmes are included. Data from monitoring undertaken after the Chernobyl accident are summarised. General monitoring of the foodchain for both artificial and natural radionuclides, and the results of relevant government-sponsored research are also described. The report includes basic information on radioactivity in the environment, radiation protection standards and describes what measures are taken to routinely monitor the foodchain and assess public risk. (Author)

Targeted Radionuclide Therapy

International Nuclear Information System (INIS)

Ersahin, Devrim; Doddamane, Indukala; Cheng, David

2011-01-01

Targeted radiotherapy is an evolving and promising modality of cancer treatment. The killing of cancer cells is achieved with the use of biological vectors and appropriate radionuclides. Among the many advantages of this approach are its selectiveness in delivering the radiation to the target, relatively less severe and infrequent side effects, and the possibility of assessing the uptake by the tumor prior to the therapy. Several different radiopharmaceuticals are currently being used by various administration routes and targeting mechanisms. This article aims to briefly review the current status of targeted radiotherapy as well as to outline the advantages and disadvantages of radionuclides used for this purpose

Radionuclides in house dust

Energy Technology Data Exchange (ETDEWEB)

Fry, F A; Green, N; Dodd, N J; Hammond, D J

1985-04-01

Discharges of radionuclides from the British Nuclear Fuel plc (BNFL) reprocessing plant at Sellafield in Cumbria have led to elevated concentrations radionuclides in the local environment. The major routes of exposure of the public are kept under review by the appropriate authorising Government departments and monitoring is carried out both by the departments and by BNFL itself. Recently, there has been increasing public concern about general environmental contamination resulting from the discharges and, in particular, about possible exposure of members of the public by routes not previously investigated in detail. One such postulated route of exposure that has attracted the interest of the public, the press and Parliament arises from the presence of radionuclides within houses. In view of this obvious and widespread concern, the Board has undertaken a sampling programme in a few communities in Cumbria to assess the radiological significance of this source of exposure. From the results of our study, we conclude that, although radionuclides originating rom the BNFL site can be detected in house dust, this source of contamination is a negligible route of exposure for members of the public in West Cumbria. This report presents the results of the Board's study of house dust in twenty homes in Cumbria during the spring and summer of 1984. A more intensive investigation is being carried out by Imperial College. (author)

Radionuclide accumulation peculiarities demonstrated by vegetable varieties

International Nuclear Information System (INIS)

Kruk, A.V.; Goncharenko, G.G.; Kilchevsky, A.V.

2004-01-01

This study focused on ecological and genetic aspects of radionuclide accumulation demonstrated by a number of vegetable varieties. The researches resulted in determining the cabbage varieties which were characterised by the minimal level of radionuclide accumulation. It was shown that the above varieties manifested the relation between radionuclide accumulation and morphobiological characteristics such as vegetation period duration and yield criteria. The study specified the genotypes with high ecological stability as regards to radionuclide accumulation: 'Beloruskaya 85' cabbage and 'Dokhodny' tomato showed the best response to Cs 137, while 'Beloruskaya 85', 'Rusinovka', 'Amager 611' cabbage varieties and 'Sprint' tomato showed the minimal level of Sr 90 accumulation. (authors)

2008 LANL radionuclide air emissions report

Energy Technology Data Exchange (ETDEWEB)

Fuehne, David P.

2009-06-01

The emissions of radionuclides from Department of Energy Facilities such as Los Alamos National Laboratory (LANL) are regulated by the Amendments to the Clean Air Act of 1990, National Emissions Standards for Hazardous Air Pollutants (40 CFR 61 Subpart H). These regulations established an annual dose limit of 10 mrem to the maximally exposed member of the public attributable to emissions of radionuclides. This document describes the emissions of radionuclides from LANL and the dose calculations resulting from these emissions for calendar year 2008. This report meets the reporting requirements established in the regulations.

2010 LANL radionuclide air emissions report /

Energy Technology Data Exchange (ETDEWEB)

Fuehne, David P.

2011-06-01

The emissions of radionuclides from Department of Energy Facilities such as Los Alamos National Laboratory (LANL) are regulated by the Amendments to the Clean Air Act of 1990, National Emissions Standards for Hazardous Air Pollutants (40 CFR 61 Subpart H). These regulations established an annual dose limit of 10 mrem to the maximally exposed member of the public attributable to emissions of radionuclides. This document describes the emissions of radionuclides from LANL and the dose calculations resulting from these emissions for calendar year 2010. This report meets the reporting requirements established in the regulations.

Preparation of porous materials for radionuclides capture

International Nuclear Information System (INIS)

Bajzikova, Anna; Smrcek, Stanislav; Kozempel, Jan; Vlk, Martin; Barta, Jan

2015-01-01

Porous materials showing promise for radionuclide capture from water at contaminated sites were prepared. Nanoporous materials (size of pores 1-100 nm) and some polymers are well suited to this purpose owing their affinity for selected radionuclides. Nanoporous metal oxides and silica gel with styrene-divinylbenzene-TODGA-modified surface were prepared, characterized and tested for radionuclide ( 227 Ac, 227 Th, 223 Ra) capture efficiency. (orig.)

Radionuclide Data Centre. Tasks and problems of obtaining the most reliable values of the nuclear physics characteristics of radionuclides and radiation physics parameters of radionuclide sources

International Nuclear Information System (INIS)

Chechev, V.P.

1994-01-01

Information is provided on the establishment of the Radionuclide Data Centre under the V.G. Khlopin Radium Institute. Its functions and areas of activity are discussed. The paper focuses on the procedure of obtaining the evaluated values of the decay and radiative characteristics of the widely used radionuclides. (author)

Adsorption and desorption of radionuclide europium(III) on multiwalled carbon nanotubes studied by batch techniques

International Nuclear Information System (INIS)

Songsheng Lu; Junzheng Xu; Caicai Zhang; Zhiwei Niu

2011-01-01

The adsorption of Eu(III) on multiwalled carbon nanotubes (MWCNTs) as a function of pH, ionic strength and solid contents are studied by batch technique. The results indicate that the adsorption of Eu(III) on MWCNTs is strongly dependent on pH values, dependent on ionic strength at low pH values and independent of ionic strength at high pH values. Strong surface complexation and ion exchange contribute to the adsorption of Eu(III) on MWCNTs at low pH values, whereas surface complexation and surface precipitation are the main adsorption mechanism of Eu(III) on MWCNTs. The desorption of adsorbed Eu(III) from MWCNTs by adding HCl is also studied and the recycling use of MWCNTs in the removal of Eu(III) is investigated after the desorption of Eu(III) at low pH values. The results indicate that adsorbed Eu(III) can be easily desorbed from MWCNTs at low pH values, and MWCNTs can be repeatedly used to remove Eu(III) from aqueous solutions. MWCNTs are suitable material in the preconcentration and solidification of radionuclides from large volumes of aqueous solutions in nuclear waste management. (author)

Reversible aqueous zinc/manganese oxide energy storage from conversion reactions

Energy Technology Data Exchange (ETDEWEB)

Pan, Huilin; Shao, Yuyan; Yan, Pengfei; Cheng, Yingwen; Han, Kee Sung; Nie, Zimin; Wang, Chongmin; Yang, Jihui; Li, Xiaolin; Bhattacharya, Priyanka; Mueller, Karl T.; Liu, Jun

2016-04-18

Rechargeable aqueous batteries are attracting growing interest for energy storage due to their low cost and high safety. Fundamental understanding of highly reversible aqueous reactions is critical for building high-performance batteries. Herein, we studied the reversibility of Zn/MnO2 battery chemistry in mild aqueous MnSO4 electrolytes. α-MnO2 nanofibers were used as a high performance cathode. Our study provides good evidence for a conversion reaction mechanism through reversible formation of short nanorods and nanoparticle aggregates. This reversible conversion reaction provides an operating voltage of 1.44 V, high capacity of 285 mAh g-1, excellent rate and capacity retention of 92% after 5000 cycles. Zn metal anode also shows high reversibility in the mild aqueous MnSO4 electrolytes. The highly reversible and stable chemistries in aqueous Zn/MnO2 batteries open new opportunity for energy storage technologies with potentially high energy density, high safety, and low cost.

Human dose pathways of radionuclides in forests

International Nuclear Information System (INIS)

Rantavaara, A.

2009-01-01

Forest soil, understorey vegetation and trees are all sources of radionuclides and human radiation doses after contaminating atmospheric deposition. People are exposed to radiation externally from sources outside the body and internally via ingestion and inhalation of radionuclides. Understorey vegetation contributes to ingestion doses through berries, herbs, wild honey, mushrooms and game meat; also trees provide feed to terrestrial birds and big game. During stay in forests people are subject to external radiation from forest floor and overstorey, and they may inhale airborne radioactive aerosol or gaseous radionuclides in ground level air. In the early phase of contamination also resuspended radionuclides may add to the internal dose of people via inhalation. People in Nordic countries are most exposed to radiation via ingestion of radionuclides in wild foods. The distribution of radionuclides in forests is changed by environmental processes, and thereby also the significance of various dose pathways to humans will change with time. External exposure is received in living environment from contaminated stemwood used as building timber and for manufacturing of furniture and other wood products. The aim of this paper is to outline the significance of various human dose pathways of radionuclides in forests considering the public and workers in forestry and production of bioenergy. Examples on effective doses are given based on two historical events, atmospheric nuclear weapon tests (mostly in 1950's and in 1960's) and the Chernobyl nuclear power plant accident in 1986. (au)

General program for the advancement of the radionuclide technology

International Nuclear Information System (INIS)

1979-12-01

The 'General Program for the Advancement of the Radionuclide Technology' was elaborated in 1978 by the 'Arbeitsgemeinschaft zur Foerderung der Radionuklidtechnik' (AFR) (Association for the Promotion of Radionuclide Technology). In addition to an inventory of the major applications of radionuclide technology, this General Program includes a comprehensive description of tasks relating to the central topics of raw materials, environment, technology and materials, health and nutrition, scientific developments of radionuclide technology. The 'General Program for the Advancement of the Radionuclide Technology' serves inter alia as a basis of evaluation in opinions on funding applications filed with the Federal Ministry for Research and Technology (BMFT) with respect to the provision of advanced techniques involving radionuclides for industrial application. (orig.) [de

Radionuclides in house dust

CERN Document Server

Fry, F A; Green, N; Hammond, D J

1985-01-01

Discharges of radionuclides from the British Nuclear Fuel plc (BNFL) reprocessing plant at Sellafield in Cumbria have led to elevated concentrations radionuclides in the local environment. The major routes of exposure of the public are kept under review by the appropriate Government departments and monitoring is carried out both by the departments and by BNFL itself. Recently, there has been increasing public concern about general environmental contamination resulting from the discharges and, in particular, about possible exposure of members of the public by routes not previously investigated in detail. One such postulated route of exposure that has attracted the interest of the public, the press and Parliament arises from the presence of radionuclides within houses. In view of this obvious and widespread concern, the Board has undertaken a sampling programme in a few communities in Cumbria to assess the radiological significance of this source of exposure. From the results of our study, we conclude that, alt...

Geochemistry and radionuclide migration

International Nuclear Information System (INIS)

Isherwood, D.

1978-01-01

Theoretically, the geochemical barrier can provide a major line of defense in protecting the biosphere from the hazards of nuclear waste. The most likely processes involved are easily identified. Preliminary investigations using computer modeling techniques suggest that retardation is an effective control on radionuclide concentrations. Ion exchange reactions slow radionuclide migration and allow more time for radioactive decay and dispersion. For some radionuclides, solubility alone may limit concentrations to less than the maximum permissible now considered acceptable by the Federal Government. The effectiveness of the geochemical barrier is ultimately related to the repository site characteristics. Theory alone tells us that geochemical controls will be most efficient in an environment that provides for maximum ion exchange and the precipitation of insoluble compounds. In site selection, consideration should be given to rock barriers with high ion exchange capacity that might also act as semi-permeable membranes. Also important in evaluating the site's potential for effective geochemical controls are the oxidation potentials, pH and salinity of the groundwater

Distribution of radionuclides during melting of carbon steel

Energy Technology Data Exchange (ETDEWEB)

Thurber, W.C.; MacKinney, J.

1997-02-01

During the melting of steel with radioactive contamination, radionuclides may be distributed among the metal product, the home scrap, the slag, the furnace lining and the off-gas collection system. In addition, some radionuclides will pass through the furnace system and vent to the atmosphere. To estimate radiological impacts of recycling radioactive scrap steel, it is essential to understand how radionuclides are distributed within the furnace system. For example, an isotope of a gaseous element (e.g., radon) will exhaust directly from the furnace system into the atmosphere while a relatively non-volatile element (e.g., manganese) can be distributed among all the other possible media. This distribution of radioactive contaminants is a complex process that can be influenced by numerous chemical and physical factors, including composition of the steel bath, chemistry of the slag, vapor pressure of the particular element of interest, solubility of the element in molten iron, density of the oxide(s), steel melting temperature and melting practice (e.g., furnace type and size, melting time, method of carbon adjustment and method of alloy additions). This paper discusses the distribution of various elements with particular reference to electric arc furnace steelmaking. The first two sections consider the calculation of partition ratios for elements between metal and slag based on thermodynamic considerations. The third section presents laboratory and production measurements of the distribution of various elements among slag, metal, and the off-gas collection system; and the final section provides recommendations for the assumed distribution of each element of interest.

DKPRO: A radionuclide decay and reprocessing code

International Nuclear Information System (INIS)

Wootan, D.; Schmittroth, F.A.

1997-01-01

The DKPRO code solves the general problem of modeling complex nuclear wastes streams using ORIGEN2 radionuclide production files. There is a continuing need for estimates of Hanford radionuclides. Physical measurements are one basis; calculational estimates, the approach represented here, are another. Given a known nuclear fuel history, it is relatively straightforward to calculate radionuclide inventories with codes such as the widely-used Oak Ridge National Laboratory code ORIGEN2

A procedure for preferential trapping of cesium cations from aqueous solutions and their separation from other inorganic cations

International Nuclear Information System (INIS)

Plesek, J.; Hermanek, S.; Selucky, P.; Williams, R.E.

1995-01-01

The title procedure is as follows. Deltahedral heteroborane anions are added to the aqueous solution containing cesium ions, precipitate (if any) is separated off, and the cesium salts involving the deltahedral heteroborane anions are trapped on activated carbon. The cobaltocarborane anion [3-Co-(1,2-C 2 B 9 H 11 ) 2 ] and/or its substitution derivatives are particularly well suited to this purpose. The process can find use in the separation of radionuclides present in waste solutions arising from spent nuclear fuel treatment. (P.A.). 1 fig

Transfer of radionuclides into human milk

International Nuclear Information System (INIS)

Steiner, M.; Wirth, E.

1998-01-01

Up until now the potential radiation exposure to breast-fed babies due to contaminated human milk has not been taken into account, when deriving international limit values and reference levels for radionuclides in foodstuffs, in air at monitored work places or for exposures in the medical field. It was the aim of the research project 'Transfer of radionuclides into human milk' to quantify the transfer of incorporated radionuclides into mother's milk, and develop simple models to estimate the radiation exposure of babies through the ingestion of human milk. The study focused on considerations of the radiation exposure due to the ingestion of contaminated foodstuffs by the mother, the inhalation of radionuclides at monitored work places, and the administration of radiopharmaceuticals to breast-feeding mothers. The blocking of infant thyroid glands by stable iodine in the case of accidental releases of radioiodine was considered as well. (orig.) [de

Biodegradation of PuEDTA and Impacts on Pu Mobility

International Nuclear Information System (INIS)

Xun, Luying; Bolton, Jr. Harvey

2001-01-01

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

Understanding and analyzing the hydro-sedimentary processes in the Bay of Toulon. Contribution for modelling the dispersion of radionuclides

International Nuclear Information System (INIS)

Dufresne, Christiane

2014-01-01

This doctoral research aims to enhance knowledge of the hydro-sedimentary processes in the Bay of Toulon and to represent these processes through a post accidental managing tool, developed to simulate the dispersion of radionuclides. This work is based on a multidisciplinary strategy, using numerical modelling and in situ measurements to study the complex problem of contaminants in the marine environment. Hydrodynamic of the Bay and water mass exchanges through the channel have been studied. Results are highly linked to the atmospheric conditions and the water exchange times of the Little Bay range from two to six days, depending on wind conditions. Recorded data in the Las and Eygoutier Rivers led to the description and the estimation of the catchment yields to the Bay, poorly studied before. With one ton of particulate matter annually discharged by the Las River, the Little Bay seems to be a sedimentation area. In case of accidental release of radionuclides, this area appears to be a trapping zone. (author)

Evaluation of conceptual, mathematical and physical-and-chemical models for describing subsurface radionuclide transport at the Lake Karachai Waste Disposal Site

International Nuclear Information System (INIS)

Rumynin, V.G.; Mironenko, V.A.; Sindalovsky, L.N.; Boronina, A.V.; Konosavsky, P.K.; Pozdniakov, S.P.

1998-01-01

The goal of this work was to develop the methodology and to improve understanding of subsurface radionuclide transport for application to the Lake Karachai Site and to identify the influence of the processes and interactions involved into transport and fate of the radionuclides. The report is focused on two sets of problems, which have to do both with, hydrodynamic and hydrogeochemical aspects of the contaminant transport

Distribution and speciation of radionuclides in the environment: their implication in radioecology

International Nuclear Information System (INIS)

Cigna, A.A.

2000-01-01

Following the discovery of X-ray and radioactivity, radioecological researches were initiated all over the world. But only after the 2nd World War the knowledge of the effects of ionizing radiations on the organisms and the processes of the diffusion of radionuclides in the environment achieved an outstanding level. On account of the great sensitivity of the radioactivity measurements, negligible amounts of radionuclides could be easily identified and measured in different environmental compartments without any slight interference with the metabolisms of living organisms. Many processes and phenomena could then be detected and studied. Ecology took advantage from such studies and its growth in a few years was probably greater than in the whole of the previous century. As a result a great interest in the determination of concentration factors in any organism spread widely in many laboratories, a large number of values were available in a few years time. Further it appeared that the transfer of the radionuclides from the environment to man could be better evaluated and monitored through the definition of some 'critical' quantity: a critical group, a critical radionuclide, a critical pathway, etc. The fallout dispersed by the experimental detonation of nuclear weapons and, more recently, the contamination due to the Chernobyl accident, were the most important sources of radionuclides in most of the environmental compartments. Undoubtedly in the post Chernobyl situation radioecology is in a better position because the description of the environment is presently much closer to reality and its conclusions much more reliable. But, as it is usual in science development, new problems appeared and new questions were asked. Speciation of radionuclides and other pollutants is considered and some of the effects on the diffusion and consequences are discussed. Finally, the application of the great amount of knowledge obtained by the radioecological research to a better

A review on studies of the transport and the form of radionuclides in the fluvial environment

Energy Technology Data Exchange (ETDEWEB)

Matsunaga, Takeshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

2001-06-01

The Japan Atomic Energy Research Institute has conducted studies with an aim to contribute to understanding the long-term behavior of atmospherically-derived radionuclides deposited on the ground. The present report reviews a series of studies among them which have especially dealt with the behavior of those radionuclides in a fluvial environment. The studies cited here include investigations of 1) the evaluation of the transport rate of the atmospherically-derived radionuclides from the ground via a river to the downstream areas where the affected water is consumed; 2) the physico-chemical form of the radionuclides in the fluvial environment. An investigation in the Kuji river watershed with {sup 137}Cs, {sup 210}Pb and {sup 7}Be has validated i) the importance of suspended particulate materials in the fluvial discharge of those radionuclides, and ii) a methodology to estimate the discharge of those radionuclides based on the regression analysis with the river water flow rate. From a viewpoint of their distribution between water and suspended particles, the form of radionuclides released by the Chernobyl accident in rivers and lakes in the vicinity of the Chernobyl Nuclear Power Plant were analyzed. As a result, a general reasonability and some cautions were suggested when commonly reported distribution ratios obtained in the laboratory and the different environment are applied to describe the partitioning of the radionuclides in specific natural environmental conditions. This experimental investigation in Chernobyl also revealed the role of natural dissolved organics in affecting the dissolution and transport of {sup 239,240}Pu, {sup 241}Am through complexation to form soluble species. Further, a chemical equilibrium model was applied to describe this complexation. The similar model was also applied for the behavior of iron and manganese (hydr)oxides in river recharged aquifers which can bear riverborne radionuclides and can influence their migration. The

A review on studies of the transport and the form of radionuclides in the fluvial environment

International Nuclear Information System (INIS)

Matsunaga, Takeshi

2001-06-01

The Japan Atomic Energy Research Institute has conducted studies with an aim to contribute to understanding the long-term behavior of atmospherically-derived radionuclides deposited on the ground. The present report reviews a series of studies among them which have especially dealt with the behavior of those radionuclides in a fluvial environment. The studies cited here include investigations of 1) the evaluation of the transport rate of the atmospherically-derived radionuclides from the ground via a river to the downstream areas where the affected water is consumed; 2) the physico-chemical form of the radionuclides in the fluvial environment. An investigation in the Kuji river watershed with 137 Cs, 210 Pb and 7 Be has validated i) the importance of suspended particulate materials in the fluvial discharge of those radionuclides, and ii) a methodology to estimate the discharge of those radionuclides based on the regression analysis with the river water flow rate. From a viewpoint of their distribution between water and suspended particles, the form of radionuclides released by the Chernobyl accident in rivers and lakes in the vicinity of the Chernobyl Nuclear Power Plant were analyzed. As a result, a general reasonability and some cautions were suggested when commonly reported distribution ratios obtained in the laboratory and the different environment are applied to describe the partitioning of the radionuclides in specific natural environmental conditions. This experimental investigation in Chernobyl also revealed the role of natural dissolved organics in affecting the dissolution and transport of 239,240 Pu, 241 Am through complexation to form soluble species. Further, a chemical equilibrium model was applied to describe this complexation. The similar model was also applied for the behavior of iron and manganese (hydr)oxides in river recharged aquifers which can bear riverborne radionuclides and can influence their migration. The obtained findings and the

Gastroesophageal reflux in children: radionuclide gastroesophagography

International Nuclear Information System (INIS)

Blumhagen, J.D.; Rudd, T.G.; Christie, D.L.

1980-01-01

Sixty-five symptomatic infants and children underwent radionuclide gastroesophagography, acid reflux testing, and barium esophagography with water-siphon testing to evaluate the clinical efficacy of the scintigraphic technique in detecting gastroesophageal reflux. After ingesting /sup 99m/Tc sulfur colloid in fruit juice, patients rested beneath the gamma camera for 30 to 60 min while esophageal activity was monitored continuously. By using the acid reflux test as a standard of comparison, the senstivity of radionuclide gastroesophagography was 75%. Because of its physiologic nature, low radiation exposure, and convenience, radionuclide gastroesophagography warrants further evaluation as a screening test for gastroesophageal reflux

Soil - plant experimental radionuclide transfer factors

International Nuclear Information System (INIS)

Dobrin, R.I.; Dulama, C.N.; Toma, Al.

2006-01-01

Some experimental research was performed in our institute to assess site specific soil-plant transfer factors. A full characterization of an experimental site was done both from pedo-chemical and radiological point of view. Afterwards, a certain number of culture plants were grown on this site and the evolution of their radionuclide burden was then recorded. Using some soil amendments one performed a parallel experiment and the radionuclide root uptake was evaluated and recorded. Hence, transfer parameters were calculated and some conclusions were drawn concerning the influence of site specific conditions on the root uptake of radionuclides. (authors)

SALTSTONE AND RADIONUCLIDE INTERACTIONS: RADIONUCLIDE SORPTION AND DESORPTION, AND SALTSTONE REDUCTION CAPACITY

Energy Technology Data Exchange (ETDEWEB)

Kaplan, D; Kimberly Roberts, K; Steven Serkiz, S; Matthew Siegfried, M

2008-10-30

The overall objective of this study was to measure a number of key input parameters quantifying geochemical processes in the subsurface environment of the Savannah River Site's (SRS's) Saltstone Facility. For the first time, sorption (K{sub d}) values of numerous radionuclides were measured with Saltstone and Vault 2 concrete. Particular attention was directed at understanding how Tc adsorbs and desorbs from these cementitious materials with the intent to demonstrate that desorption occurs at a much slower rate than adsorption, thus permitting the use of kinetic terms instead of (or along with) the steady state K{sub d} term. Another very important parameter measured was the reduction capacity of these materials. This parameter is used to estimate the duration that the Saltstone facility remains in a reduced chemical state, a condition that maintains several otherwise mobile radionuclides in an immobile form. Key findings of this study follow. K{sub d} values for Am, Cd, Ce, Co, Cs, Hg, I, Np, Pa, Pu, Se, Sn, Tc, U, and Y for Saltstone and Vault 2 concrete were measured under oxidized and reduced conditions. Precipitation of several of the higher valence state radionuclides was observed. There was little evidence that the Vault 2 and Saltstone K{sub d} values differed from previous SRS K{sub d} values measured with reducing grout (Kaplan and Coates 2007). These values also supported a previous finding that K{sub d} values of slag-containing cementitious materials, tend to be greater for cations and about the same for anions, than regular cementitious materials without slag. Based on these new findings, it was suggested that all previous reducing concrete K{sub d} values be used in future PAs, except Np(V) and Pu(IV) K{sub d} values, which should be increased, and I values, which should be slightly decreased in all three stages of concrete aging. The reduction capacity of Saltstone, consisting of 23 wt-% blast furnace slag, was 821.8 microequivalents per

Sources of anthropogenic radionuclides in the environment: a review

International Nuclear Information System (INIS)

Hu Qinhong; Weng Jianqing; Wang Jinsheng

2010-01-01

Studies of radionuclides in the environment have entered a new era with the renaissance of nuclear energy and associated fuel reprocessing, geological disposal of high-level nuclear wastes, and concerns about national security with respect to nuclear non-proliferation. This work presents an overview on sources of anthropogenic radionuclides in the environment, as well as a brief discussion of salient geochemical behavior of important radionuclides. We first discuss the following major anthropogenic sources and current developments that have lead, or could potentially contribute, to the radionuclide contamination of the environment: (1) nuclear weapons program; (2) nuclear weapons testing; (3) nuclear power plants; (4) uranium mining and milling; (5) commercial fuel reprocessing; (6) geological repository of high-level nuclear wastes that include radionuclides might be released in the future, and (7) nuclear accidents. Then, we briefly summarize the inventory of radionuclides 99 Tc and 129 I, as well as geochemical behavior for radionuclides 99 Tc, 129 I, and 237 Np, because of their complex geochemical behavior, long half-lives, and presumably high mobility in the environment; biogeochemical cycling and environment risk assessment must take into account speciation of these redox-sensitive radionuclides.

Dispersion of radionuclides in the European north-western seas: observations and modelling

International Nuclear Information System (INIS)

Bailly du Bois, Pascal

2013-01-01

In this report for an Accreditation to supervise research (HDR), the author reports the use over 30 years by the Cherbourg-Octeville IRSN Laboratory of artificial radionuclides in solution in sea water as oceanographic markers. Such measurements on radio-markers which are soluble in sea water, enabled a better knowledge of dissolved substance displacements in north-western seas of Europe, notably the Channel, the North Sea, the Celtic Sea, and the Irish Sea. The author reports researches which aimed at studying the dispersion of radionuclides in seawater and their use as water mass markers, at validating hydrodynamic models of dispersion at different time-space scales, at the understanding and simulation of the sedimentary transport, and at studying the transfer to living species. These different topics give the document its structure [fr

Synthesis and characterization of surfactant immobilised layered hydrotalcite clays for the adsorption of thorium (IV) from aqueous phase: kinetics and equilibrium study

International Nuclear Information System (INIS)

Rijith, S.; Renju, K.; Sumi, V.S.; Shibli, S.M.A.; Anirudhan, T.S.

2014-01-01

Thorium is a naturally occurring radioactive element widely distributed over the earth's crust with nuclear significance. The toxic nature of this radionuclide, even at trace levels, has been a public health problem for many years. Removal of thorium (IV) from aqueous solutions with surfactant immobilised calcined hydrotalcite clays (HTS) was investigated using batch adsorption technique. Based on cost effectiveness, availability, adsorptive and regenerative properties, layered clays are reported to be excellent materials for heavy metal ions adsorption

Radionuclide characterization of environmental air around nuclear facilities

International Nuclear Information System (INIS)

Gede Sutresna Wijaya; Anung Muharini

2015-01-01

Air is an important environmental component in human life. Presence of air pollutants or contaminants will have a negative impact on human health. According to the existence of a nuclear facility in Yogyakarta, the characterization of radionuclides in the air is absolutely necessary to ensure the safety of people and the environment and also to supervise the safe operation of the facility. In this research the characterization of radionuclides in the air was carried through the air sampling by using High Volume Air Sampler equipped with filter TFA 2133, followed by analysis using combination of a gamma and alpha spectrometers. The concentration of radioactivity in the air fluctuates depending on the time and duration of sampling. Characterization of gamma emitting radionuclides in the air is dominated by radon progeny radionuclides such as 214 Pb, 214 Bi with activity 20.09 ± 1.23 until 32.91 ± 4.87 Bq/m 3 and 31.22 ± 1.76 until 44.25 ± 4.91 Bq/m 3 . Alpha emitter radionuclide was dominated by 214 Po (7.69 MeV) which is also radon progeny and a primordial radionuclides. It can be concluded that the presence of radionuclides in the environmental air not as a product resulting from the operation of nuclear facilities in Yogyakarta. (author)

Harvard--MIT research program in short-lived radiopharmaceuticals. Progress report, September 1, 1977--April 30, 1978. [/sup 99m/Tc, positron-emitting radionuclides

Energy Technology Data Exchange (ETDEWEB)

Adelstein, S.J.; Brownell, G.L.

1978-05-01

Progress is reported on the following studies: chemistry studies designed to achieve a more complete understanding of the fundamental chemistry of technetium in order to facilitate the design of future radiopharmaceuticals incorporating the radionuclide /sup 99m/Tc; the development of new radiopharmaceuticals intended to improve image quality and lower radiation doses by the use of short-lived radionuclides and disease-specific agents; the development of short-lived positron-emitting radionuclides which offer advantages in transverse section imaging of regional physiological processes; and studies of the toxic effects of particulate radiation.

A basic toxicity classification of radionuclides

International Nuclear Information System (INIS)

1963-01-01

In the course of its work in the field of health and safety the International Atomic Energy Agency has often met the practical requirement for grading radionuclides in order of their relative radiotoxicities. This need was particularly evident when the Agency's Basic Safety Standards for the protection of health against ionizing radiation were in preparation, when it was necessary to exempt quantities of radionuclides from inclusion in the norms. A basic toxicity grading might be of help to laboratories in meeting some of their requirements in problems related to waste management as well as for the design of experimental facilities. It should also serve as a basis for the development of safety criteria for laboratory equipment and procedures for handling and transporting various quantities and kinds of radionuclides. The purpose of the present Report is to make a toxicity grading of the radionuclides according to the risk of biological injury which they may cause when they have become incorporated in the human body. 4 refs, 4 tabs

A basic toxicity classification of radionuclides

Energy Technology Data Exchange (ETDEWEB)

1963-04-01

In the course of its work in the field of health and safety the International Atomic Energy Agency has often met the practical requirement for grading radionuclides in order of their relative radiotoxicities. This need was particularly evident when the Agency's Basic Safety Standards for the protection of health against ionizing radiation were in preparation, when it was necessary to exempt quantities of radionuclides from inclusion in the norms. A basic toxicity grading might be of help to laboratories in meeting some of their requirements in problems related to waste management as well as for the design of experimental facilities. It should also serve as a basis for the development of safety criteria for laboratory equipment and procedures for handling and transporting various quantities and kinds of radionuclides. The purpose of the present Report is to make a toxicity grading of the radionuclides according to the risk of biological injury which they may cause when they have become incorporated in the human body. 4 refs, 4 tabs.

Method of preparing radionuclide doses

International Nuclear Information System (INIS)

Kuperus, J.H.

1987-01-01

A method is described of preparing aliquot dosea of a tracer material useful in diagnostic nuclear medicine comprising: storing discrete quantities of a lyophilized radionuclide carrier in separate tubular containers from which air and moisture is excluded, selecting from the tubular containers a container in which is stored a carrier appropriate for a nuclear diagnostic test to be performed, interposing the selected container between the needle and the barrel of a hypodermic syringe, and drawing a predetermined amount of a liquid containing a radionuclide tracer in known concentration into the hypodermic syringe barrel through the hypodermic needle and through the selected container to dissolve the discrete quantity of lyophilized carrier therein to combine the carrier with the radionuclide tracer to form an aliquot dose of nuclear diagnostic tracer material, as needed

Worldwide dispersion and deposition of radionuclides produced in atmospheric tests.

Science.gov (United States)

Bennett, Burton G

2002-05-01

Radionuclides produced in atmospheric nuclear tests were widely dispersed in the global environment. From the many measurements of the concentrations in air and the deposition amounts, much was learned of atmospheric circulation and environmental processes. Based on these results and the reported fission and total yields of individual tests, it has been possible to devise an empirical model of the movement and residence times of particles in the various atmospheric regions. This model, applied to all atmospheric weapons tests, allows extensive calculations of air concentrations and deposition amounts for the entire range of radionuclides produced throughout the testing period. Especially for the shorter-lived fission radionuclides, for which measurement results at the time of the tests are less extensive, a more complete picture of levels and isotope ratios can be obtained, forming a basis for improved dose estimations. The contributions to worldwide fallout can be inferred from individual tests, from tests at specific sites, or by specific countries. Progress was also made in understanding the global hydrological and carbon cycles from the tritium and 14C measurements. A review of the global measurements and modeling results is presented in this paper. In the future, if injections of materials into the atmosphere occur, their anticipated motions and fates can be predicted from the knowledge gained from the fallout experience.

Transfer parameters of radionuclides in the marine environment

International Nuclear Information System (INIS)

1996-03-01

To increase the accuracy of estimation of exposure dose by radionuclides in the marine, the informations of environmental parameter data in the marine were collected, arranged and discussed. The informations were discussed by 'a sectional committee of marine suspended solids and sediment'. The following problems were investigated and the studies were recorded in this report, clear explanation about the distribution factor (kd), the estimation method of kd, the fluctuating factor of kd data (properties of suspension and sediment, differences among the experimental methods), the physical and chemical behavior of radionuclides, sediment of radionuclides by means of sorption to the suspended particles in the marine, sorption of radionuclides into the marine soil (sediment), re-eluent of radionuclides sorpted in the marine soil (sediment), and relation between marine organism and marine suspended materials and sediment. (S.Y.)

Radionuclides retention in C-S-H, main phases of cement matrices for low and intermediate-level wastes; Retencion de radionuclidos en C-S-H, principales fases de matrices de cemento para desechos de bajo y medio nivel

Energy Technology Data Exchange (ETDEWEB)

Badillo A, V. E.; Lopez R, C.; Vidal M, J. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Gutierrez B, O., E-mail: veronica.badillo@inin.gob.mx [Instituto Tecnologico de Toluca, Av. Tecnologico s/n, Exrancho La Virgen, Metepec, Estado de Mexico (Mexico)

2014-10-15

Knowing that the behavior of cementitious materials based on hydraulic binder called cement is essentially determined by the physicochemical evolution of the cement paste (water + cement) which constitutes it, the evolution of the cement paste in contact with different aqueous solutions is studied since one of the main risks in safety of systems is composed of surface and groundwater, which contribute to the alteration of the different barriers and represent the main way of radionuclides transport. The calcium silicates CSH are the main phases that compose the systems based on Portland cement. The hydrates calcium silicates possess a high degree of structural complexity which includes crystalline, partially crystalline and amorphous phases. In this study the microstructures of the CSH phases as well as the retention of radionuclide Sr (II) are studied through the {sup 87m}Sr in formulations of water/cement w/c = 0.55; experimental values of K d low around 20 ml g{sup -1} are obtained in function of hydration time of the cement paste in equilibrium with aqueous solutions. (Author)

Analytical methods for determination of radiochemical and radionuclidic purity of radiopharmaceuticals containing sup(99m)Tc and sup(113m)In. Part of a coordinated programme on radiopharmaceuticals

International Nuclear Information System (INIS)

Galatzeanu, I.

1974-01-01

The obtained results on radiochemical and radionuclidic purities determination of sup(99m)Tc and sup(113m)In-radiopharmaceuticals proved to be a good tool for small hospital units and laboratories in satisfying their duty to improve the quality control. The complicated behaviour of technetium in aqueous solutions during the preparation of radiopharmaceuticals, needs further research work to elucidate the mechanisms of interaction of reduced species with media and their disproportionation

Cooperative research at JAERI on the consequences of the Chernobyl accident. 3. Distribution and migration characteristics of long-lived radionuclides in the environment around the damaged Chernobyl reactor

International Nuclear Information System (INIS)

Amano, Hikaru

2001-01-01

The purpose of this study was to elucidate the actual long-term migration characteristics of radionuclides released and accumulated on the earth surface environment after the reactor accident. The objective areas were mainly in 30 km distant areas from the reactor. The study concerned the distribution of radionuclides on the ground surface, their physical and chemical forms, their migration characteristics, their migration from the ground to aqueous system like river, their physical and chemical forms in that system, their migration into vegetables, and their re-floating and concentration in air. The study involved those methods such as a newly developed liquid scintillation counting of 241 Pu for assessing 241 Am accumulation and the alpha-track method for detection of hot particles. Findings were: Hot particles of small diameters around several microns were still present; Depth distribution of radionuclides was dependent on the soil sort; Chemical forms of 90 Sr, 137 Cs and transuranium elements were different; Depth distribution in the soil depended on chemical forms; Annual change of radionuclides was evident in air; Migration coefficients to vegetables were determined; High molecular weight organic colloid was important in the migration to water system; Amounts of 137 Cs and transuranium elements depended on those of suspended matters in the river water and >90% 90 Sr were in soluble forms; Apparent partition ratios (soluble/suspended) of radionuclides in the river and lake were determined; Soluble transuranium elements were bound to humus materials in the river. (K.H.)

The potential of coconut fibers in raw and treated forms to remove 241Am from aqueous solutions

International Nuclear Information System (INIS)

Fonseca, Heverton C.O.; Jesus, Nella N.M. de; Nobre, Vanessa B.; Potiens Junior, Ademar; Sakata, Solange K.

2013-01-01

In the Radioactive Waste Management (GRR) at the Nuclear and Energy Research Institute (IPEN/CNEN-SP) vegetal biomass has been studied as adsorbent to remove radioisotopes from radioactive liquid wastes as part of the radioactive waste treatment program. In this work coconuts fiber was evaluate as biosorbent to remove 241 Am from aqueous solutions and many different parameters were studied such as particle size (35 and 80 mesh) and contact time (between 5 and 60 minutes). In order to evaluate if the treated biomass could remove more 241 Am the experiments were also performed using raw biomass and treated with H 2 O 2 in basic conditions. When the experiment was carried out using raw coconuts fiber with 80 mesh, neutral conditions after 5 minutes of contact time 99% of the radionuclide was removed from the aqueous solution. This result shows the potential of this biomass to remove 241 Am from radioactive liquid wastes. (author)

Production of medical short-lived radionuclides in Canada

International Nuclear Information System (INIS)

Wiebe, L.I.

1985-01-01

The production of radionuclides for medical and biomedical research in Canada has been reviewed with respect to the national geographic and demographic characteristics which influence their use. The types of facilities available for the production of short-lived radionuclides have been summarized, and a tabulation of the radionuclides that are produced has been presented. In broad terms production facilities can be classified as belonging to one of two groups, nuclear reactor or charged-particle accelerators. The charged-particle accelerators produce the more neutron-deficient and (because of the resultant decay properties) the more useful radionuclides for medical application. The nuclear reactor facilities for radionuclide production range in size and capacity from the high-flux research reactors of AECL to the six SLOWPOKE reactors, five of which are located on university campuses across the country. The McMaster University reactor is used to produce curie quantities of fluorine-18 weekly. Millicurie amounts of a large number of radionuclides, most of which have half-lives ranging from 2 to 50 hr, are produced in the low-flux reactors, in support of basic medical research

Simulation of radionuclide transport in U.S. agriculture

International Nuclear Information System (INIS)

Sharp, R.D.; Baes, C.F. III.

1982-01-01

Because of the recent concern about the impact of energy technologies on man and related health effects, there has emerged a need for models to calculate or predict the effects of radionuclides on man. A general overview is presented of a model that calculates the ingrowth of radionuclides into man's food chain. The FORTRAN IV computer program TERRA, Transport of Environmentally Released Radionuclides in Agriculture, simulates the build-up of radionuclides in soil, four plant food compartments, in meat and milk from beef, and in the livestock food compartments that cause radionuclide build-up in milk and meat from beef. A large data set of spatially oriented parameters has been developed in conjunction with TERRA. This direct-access data set is called SITE, Specific Information on the Terrestrial Environment, and contains 35 parameters for each of 3525 half-degree longitude-latitude cells which define the lower 48 states. TERRA and SITE are used together as a package for determining radionuclide concentrations in man's food anywhere within the conterminous 48 states due to atmospheric releases

Assessment of the important radionuclides in nuclear waste

International Nuclear Information System (INIS)

Kerrisk, J.F.

1985-10-01

The relative importance of the various radionuclides contained in nuclear waste has been assessed by consideration of (1) the quantity of each radionuclide present, (2) the Environmental Protection Agency's release limits for radionuclides, (3) how retardation processes such as solubility and sorption affect radionuclie transport, and (4) the physical and chemical forms of radionuclides in the waste. Three types of waste were reviewed: spent fuel, high-level waste, and defense high-level waste. Conditions specific to the Nevada Nuclear Waste Storage Investigations project potential site at Yucca Mountain were used to describe radionuclide transport. The actinides Am, Pu, Np, and U were identified as the waste elements for which solubility and sorption data were most urgently needed. Other important waste elements were identified as Sr, Cs, C, Ni, Zr, Tc, Th, Ra, and Sn. Under some conditions, radionuclides of three elements (C, Tc, and I) may have high solubility and negligible sorption. The potential for transport of some waste elements (C and I) in the gas phase must also be evaluated for the Yucca Mountain Site. 12 refs., 17 tabs

Interaction of radionuclides with argillite from the Eleana Formation on the Nevada Test Site

International Nuclear Information System (INIS)

Dosch, R.G.; Lynch, A.W.

1979-02-01

Distribution coefficients have been determined for 137 Cs, 85 Sr, 144 Ce, 99 Tc, 152 Eu, 238 Pu, 244 Cm, and 243 Am between argillite from the Eleana Formation on the Nevada Test Site (NTS) and several aqueous phases. Radionuclide concentrations in the range of 1 to 0.001 μCi/ml were used with contact times of 14, 28, and 56 days. Reaction mechanism, concentration effects, exchange capacity, equilibration times, and particle size effects were addressed in a more comprehensive study of the interaction of argillite with Cs in deionized water. The experimental parameters used in the distribution coefficient measurements were based in part on this work. The aqueous phases included a simulated groundwater with composition based on the analysis of a NTS groundwater, the same simulant and deionized water which were pre-equilibrated with powdered argillite, and a groundwater simulant with approximately the same qualitative composition of the NTS simulant, but with a higher ionic strength. A system to provide continuous pH control by CO 2 addition during equilibration of the argillite-solution mixtures was designed and assembled. Initial experiments were done with Cs and Eu and the effects of pH on their distribution coefficients are discussed

Radionuclide Retention in Concrete Wasteforms - FY13

Energy Technology Data Exchange (ETDEWEB)

Snyder, Michelle MV; Golovich, Elizabeth C.; Wellman, Dawn M.; Crum, Jarrod V.; Lapierre, Robert; Dage, Denomy C.; Parker, Kent E.; Cordova, Elsa A.

2013-10-15

Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. Data collected throughout the course of this work will be used to quantify the efficacy of concrete wasteforms, similar to those used in the disposal of low-level waste and mixed low-level waste, for the immobilization of key radionuclides (i.e., uranium, technetium, and iodine). Data collected will also be used to quantify the physical and chemical properties of the concrete affecting radionuclide retention.

Risk governance on radionuclide contamination in food in Japan

International Nuclear Information System (INIS)

Sekizawa, Jun

2012-01-01

A large scale nuclear power plant accident happened after the great earthquake in Fukushima in March 2011. There was several critical mismanagement of the accident which resulted in the radio-nuclides release in the environment. Furthermore the information delay and the lack in delivery of clear and comprehensible explanation of the risk have been causing huge anxieties and worries among people living near to the site, and also people in the nation. Risk assessment appeared not to meet appropriately requests of risk management authorities and also people. Author has been trying to straighten the large amounts of data on radionuclide contamination in foods so as for people to easily understand the real situation with succinct messages explaining risk and to take appropriate actions in facing the risk. Appropriate responses and coordination among the risk managing authorities are indispensable especially in this kind of huge accident which may entail vast scale and long lasting risk and a new paradigm of the food safety governance is required in Japan. (author)

21 CFR 892.1390 - Radionuclide rebreathing system.

Science.gov (United States)

2010-04-01

... gaseous or volatile radionuclide or a radionuclide-labeled aerosol and permit it to be respired by the patient during nuclear medicine ventilatory tests (testing process of exchange between the lungs and the...

Modeling the Hydrogeochemical Transport of Radionuclides through Engineered Barriers System in the Proposed LLW Disposal Site of Taiwan - 12082

Energy Technology Data Exchange (ETDEWEB)

Lin, Wen-Sheng [Hydrotech Research Institute, National Taiwan University, Taipei, Taiwan (China); Liu, Chen-Wuing; Tsao, Jui-Hsuan [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan (China); Li, Ming-Hsu [Institute of Hydrological and Oceanic Sciences, National Central University, Jhongli, Taiwan (China)

2012-07-01

A proposed site for final disposal of low-level radioactive waste located in Daren Township of Taitung County along the southeastern coast has been on the selected list in Taiwan. The geology of the Daren site consists of argillite and meta-sedimentary rocks. A mined cavern design with a tunnel system of 500 m below the surface is proposed. Concrete is used as the main confinement material for the engineered barrier. To investigate the hydrogeochemical transport of radionuclides through engineered barriers system, HYDROGEOCHEM5.0 model was applied to simulate the complex chemical interactions among radionuclides, the cement minerals of the concrete, groundwater flow, and transport in the proposed site. The simulation results showed that the engineered barriers system with the side ditch efficiently drained the ground water and lowered the concentration of the concrete degradation induced species (e.g., hydrogen ion, sulfate, and chloride). The velocity of groundwater observed at side ditch gradually decreased with time due to the fouling of pore space by the mineral formation of ettringite and thaumasite. The short half-life of Co-60, Sr-90 and Cs-137 significantly reduced the concentrations, whereas the long half-life of I-129(1.57x10{sup 7} years) and Am-241(432 years) remain stable concentrations at the interface of waste canister and concrete barrier after 300 years. The mineral saturation index (SI) was much less than zero due to the low aqueous concentration of radionuclide, so that the precipitation formation of Co-60, Sr-90, I-129, Cs-137 and Am-241 related minerals were not found. The effect of adsorption/desorption (i.e., surface complexation model) could be a crucial geochemical mechanism for the modeling of liquid-solid phase behavior of radionuclide in geochemically dynamic environments. Moreover, the development of advanced numerical models that are coupled with hydrogeochemical transport and dose assessment of radionuclide is required in the future

Recent developments in assessment of long-term radionuclide behavior in the geosphere-biosphere subsystem

International Nuclear Information System (INIS)

Smith, G.M.; Smith, K.L.; Kowe, R.; Pérez-Sánchez, D.; Thorne, M.; Thiry, Y.; Read, D.; Molinero, J.

2014-01-01

Decisions on permitting, controlling and monitoring releases of radioactivity into the environment rely on a great variety of factors. Important among these is the prospective assessment of radionuclide behavior in the environment, including migration and accumulation among and within specific environmental media, and the resulting environmental and human health impacts. Models and techniques to undertake such assessments have been developed over several decades based on knowledge of the ecosystems involved, as well as monitoring of previous radionuclide releases to the environment, laboratory experiments and other related research. This paper presents developments in the assessment of radiation doses and related research for some of the key radionuclides identified as of potential significance in the context of releases to the biosphere from disposal facilities for solid radioactive waste. Since releases to the biosphere from disposal facilities involve transfers from the geosphere to the biosphere, an important aspect is the combined effects of surface hydrology, near-surface hydrogeology and chemical gradients on speciation and radionuclide mobility in the zone in which the geosphere and biosphere overlap (herein described as the geosphere-biosphere subsystem). In turn, these aspects of the environment can be modified as a result of environmental change over the thousands of years that have to be considered in radioactive waste disposal safety assessments. Building on the experience from improved understanding of the behavior of the key radionuclides, this paper proceeds to describe development of a generic methodology for representing the processes and environmental changes that are characteristic of the interface between the geosphere and the biosphere. The information that is provided and the methodology that is described are based on international collaborative work implemented through the BIOPROTA forum, (www.bioprota.org). - Highlights: • Geological

Naturally occurring radionuclides in agricultural products: An overview

International Nuclear Information System (INIS)

Hanlon, E.A.

1994-01-01

Low levels of naturally occurring radionuclides exist in phosphatic clays, a by-product of phosphatic mining and beneficiation processes. Concerns about these radionuclides entering the human food chain were an immediate research priority before the phosphate clays could be reclaimed for intensive agricultural purposes. Efforts included the assembly of a large body of data from both sons and plants, part of which were produced by the Polk County (Florida) Mined Lands Agricultural Research/Demonstration Project MLAR/DP. Additional detailed studies involving dairy and beef cattle (Bos taurus) were conducted by researchers working with the MLAR/DP. A national symposium was conducted in which data concerning the MLAR/DP work and other research projects also dealing with naturally occurring radionuclides in agriculture could be discussed. The symposium included invited review papers dealing with the identification of radionuclide geological origins, the geochemistry and movement of radionuclides within the environment, mechanisms of plant uptake, entry points into the food chain, and evaluation of dose and risk assessment to the consumer of low levels of radionuclides. The risk to human health of an individual obtaining 0.1 of his or her dietary intake from crops produced on phosphatic clays increased by 1 in 5 x 10 6 /yr above a control individual consuming no food grown on phosphatic clays. Leaf tissues were found to be generally higher than fruit, grain, or root tissues. The natural range in radionuclide content among various food types was greater than the difference in radionuclides content between the same food produced on phosphatic clays vs. natural soils. 19 refs

Experimental methodology to study radionuclide sorption and migration in geological formations and engineered barriers of waste repositories

International Nuclear Information System (INIS)

Rojo Sanz, H.

2010-01-01

In Spain, the waste management options include either the possibility of a final storage in a deep geological repository (DGR) or the centralized temporal surface disposal (CTS). DGRs are based in a multi-barrier concept with the geological barrier and including the vitrified waste, the metal containers and engineered barriers such as compacted bentonite and cement-based materials. On the other hand, CTS mainly considers concrete and cement to confine the metal canisters containing the waste. Radionuclide migration will mainly take place by the existence of chemical concentration gradients being thus diffusion the main transport mechanism or by the existence of hydraulic gradients due to the existence of water-conductive fractures. Radionuclide sorption/retention on the materials composing the natural and engineered barriers is the fundamental process controlling contaminant migration. The evaluation of sorption parameters and the understanding of the different mechanisms leading to radionuclide retention are very important issues. The study of diffusion processes is very relevant as well. This paper describes the main experimental methodologies applied to analyse radionuclide transport in the different barriers of radioactive repositories. Particularly we focused on obtaining of retention parameters as distribution coefficients, kd, or retardation factors, Rf, and diffusion coefficients of radionuclides. (Author) 6 refs.

Water hyacinth for phytoremediation of radioactive waste simulate contaminated with cesium and cobalt radionuclides

International Nuclear Information System (INIS)

Saleh, H.M.

2012-01-01

Highlights: ► Phytoremediation of radioactive wastes containing 137 Cs and 60 Co radionuclides. ► Using water hyacinth for radioactive waste treatment. ► Bioaccumulation of radionuclides from radioactive waste streams. ► Factors affecting bioaccumulation of 137 Cs and 60 Co using floating plants. - Abstract: Phytoremediation is based on the capability of plants to remove hazardous contaminants present in the environment. This study aimed to demonstrate some factors controlling the phytoremediation efficiency of live floating plant, water hyacinth (Eichhornia crassipes), towards the effluents contaminated with 137 Cs and/or 60 Co. Cesium has unknown vital biological role for plant while cobalt is one of the essential trace elements required for plant. The main idea of this work i.e. using undesirable species, water hyacinth, in purification of radiocontaminated aqueous solutions has been receiving much attention. The controlling factors such as radioactivity concentration, pH values, the amount of biomass and the light were studied. The uptake rate of radiocesium from the simulated waste solution is inversely proportional to the initial activity content and directly proportional to the increase in mass of plant and sunlight exposure. A spiked solution of pH ≈ 4.9 was found to be the suitable medium for the treatment process. The uptake efficiency of 137 Cs present with 60 Co in mixed solution was higher than if it was present separately. On the contrary, uptake of 60 Co is affected negatively by the presence of 137 Cs in their mixed solution. Sunlight is the most required factor for the plant vitality and radiation resistance. The results of the present study indicated that water hyacinth may be a potential candidate plant of high concentration ratios (CR) for phytoremediation of radionuclides such as 137 Cs and 60 Co.

Migration of radionuclides through a river system

Energy Technology Data Exchange (ETDEWEB)

Matsunaga, Takeshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1999-03-01

Migration behavior of several atmospherically-derived radionuclides in a river watershed was studied. A main interest was in their relocation from the ground soil of the watershed to a downstream region through a river. Studied radionuclides are: {sup 137}Cs generated by weapon tests in the atmosphere; {sup 210}Pb and {sup 7}Be of naturally occurring radionuclides; {sup 137}Cs, {sup 90}Sr, {sup 239,240}Pu and {sup 241}Am released by the Chernobyl nuclear power plant accident. Dominance of the form in suspended solid in river water (particulate form) was qualified for the radionuclides in the Kuji river watershed. An importance of discharge in flooding was also confirmed. A historical budget analysis for weapon test derived {sup 137}Cs was presented for the Hi-i river watershed and its accompanied lake sediment (Lake Shinji). The work afforded a scheme of a fate of {sup 137}Cs after falling on the ground soil and on the lake surface. Several controlling factors, which can influence on the chemical form of radionuclides discharged to a river, were also investigated in the vicinity of the Chernobyl nuclear power plant. A special attention was paid on the association of the radionuclides with dissolved species in water. Preferential association of Pu and Am isotopes to a large molecular size of dissolved matrices, probably of humic substances, was suggested. (author)

Mathematical simulation of sediment and radionuclide transport in estuaries

International Nuclear Information System (INIS)

Onishi, Y.; Trent, D.S.

1982-11-01

The finite element model LFESCOT (Flow, Energy, Salinity, Sediment and Contaminant Transport Model) was synthesized under this study to simulate radionuclide transport in estuaries to obtain accurate radionuclide distributions which are affected by these factors: time variance, three-dimensional flow, temperature, salinity, and sediments. Because sediment transport and radionuclide adsorption/desorption depend strongly on sizes or types of sediments, FLESCOT simulates sediment and a sediment-sorbed radionuclide for the total of three sediment-size fractions (or sediment types) of both cohesive and noncohesive sediments. It also calculates changes of estuarine bed conditions, including bed elevation changes due to sediment erosion/deposition, and three-dimensional distributions of three bed sediment sizes and sediment-sorbed radionuclides within the bed. Although the model was synthesized for radionuclide transport, it is general enough to also handle other contaminants such as heavy metals, pesticides, or toxic chemicals. The model was checked for its capability for flow, water surface elevation change, salinity, sediment and radionuclide transport under various simple conditions first, confirming the general validity of the model's computational schemes. These tests also revealed that FLESCOT can use large aspect ratios of computational cells, which are necessary in handling long estuarine study areas. After these simple tests, FLESCOT was applied to the Hudson River estuary between Chelsea and the mouth of the river to examine how well the model can predict radionuclide transport through simulating tidally influenced three-dimensional flow, salinity, sediment and radionuclide movements with their interactions

Online estimation of radionuclide transportation in water environment

International Nuclear Information System (INIS)

Yi-Jing Zhang; Li-Sheng Hu

2017-01-01

Transportation evaluation of the radionuclide waste discharged from nuclear power plants is an essential licensing issue, especially for inland sites. Basically, the dynamics of radionuclide transportation are nonlinear and time-varying. Motivated by its time-consuming computation, the work proposed an online estimation method for the radionuclide waste in water surface. After extracting the nonlinearity of factors influencing radionuclide transportation, the method utilizes transfer function and generalized autoregressive conditional heteroskedasticity models to perform deterministic and probabilistic estimations. It turns out that, the resulting predictions show high accuracy and can optimize the online discharge management of radioactive waste for nuclear power plants. (author)

Radionuclides in terrestrial ecosystems

International Nuclear Information System (INIS)

Howard, B.J.; Kennedy, V.H.; Nelson, A.

1983-06-01

A bibliographical database has been developed to provide quick access to research and background literature in the field of radioecology. This is a development of an earlier database described by Nelson (Bocock 1981). ITE's particular fields of interest have led to a subject bias in the bibliography towards studies in Cumbria, especially those concerned with radionuclides originating from the reprocessing plant at Sellafield, and towards ecological research studies that are complementary to radionuclide studies. Other subjects covered, include the chemistry of radionuclides, budgets and transfers within ecosystems and techniques for the analysis of environmental samples. ITE's research objectives have led to the establishment of a specialized database which is intended to complement rather than compete with the large international databases made available by suppliers such as IRS-DIALTECH or DIALOG. Currently the database holds about 1900 references which are stored on a 2 1/2 megabyte hard disk on a Digital PDP11/34 computer operating under a time shared system. The references follow a standard format. (author)

Status report on radionuclide transfer

International Nuclear Information System (INIS)

1980-01-01

At the suggestion of the Federal Minstry of the Interior, in June 1978, a group of scientists from several institutions who are active in the field of radionuclide transfer or are interested in these problems got together. During the discussions of the work team, especially the transfer soil/plants was emphasized. Then the work team set up a status report on the transfer of the radionuclides relevant in the sense of the radiation protection act. The nuclides H 3 and C14, the isotopes of the Sr, J, and Cs, Tc99, the so-called corrosion nuclides Mn54, Fe59, co-isotopes and Zn65, and isotopes of Pu, Am, and Cm were regarded as important for a possible radiation exposition. Recent investigations revealed that also the natural radionuclides Ra226, Po210, and Pb210 should be covered by the investigations. The goal of this status report is to present the level of knowledge on the transfer of these radionuclides to man in a brief form, giving hints at the most important literature. It was requested by the Federal Ministry of the Interior, as fas as possible, to indicate transfer factors which are necessary for the radio-occology act to be decreed according to Para. 45 of the radiation protection act. Another goal of the report was to show the gap in the knowledge on the radio nuclide transfer. This was thought to help to create a basis for the decisions of the Federal Ministry concerning the support of other investigation projects in the field of transfer of radionuclides. (orig./MG) [de

The fate and importance of radionuclides produced in nuclear events

Energy Technology Data Exchange (ETDEWEB)

Shore, B; Anspaugh, L; Chertok, R; Gofman, J; Harrison, F; Heft, R; Koranda, J; Ng, Y; Phelps, P; Potter, G; Tamplin, A [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

1969-07-01

Some of the major program at the Bio-Medical Division concerned with the fate and importance of the fission products, the radionuclides induced in the device materials, the radionuclides induced in the environment surrounding the device, and the tritium produced in Plowshare cratering events will be discussed. These programs include (1) critical unknowns in predicting organ and body burdens from radionuclides produced in cratering events; (2) the analysis with a high-resolution solid state gamma ray spectrometer of radionuclides in complex biological and environmental samples; (3) the characterization of radioactive particles from cratering detonation; (4) the biological availability to beagles, pigs and goats of radionuclides in Plowshare debris; (5) the biological availability to aquatic animals of radionuclides in Plowshare and other nuclear debris and the biological turnover of critical nuclides in specific aquatic animals; (6) the biological availability of Plowshare and other nuclear debris radionuclides to dairy cows and the transplacental transport of debris radionuclides in the dairy cow; (7) the persistence and behavior of radionuclides, particularly tritium, at sites of Plowshare and other nuclear detonations; and (8) somatic effects of Low Dose Radiation: Chromosome studies. (author)

The fate and importance of radionuclides produced in nuclear events

International Nuclear Information System (INIS)

Shore, B.; Anspaugh, L.; Chertok, R.; Gofman, J.; Harrison, F.; Heft, R.; Koranda, J.; Ng, Y.; Phelps, P.; Potter, G.; Tamplin, A.

1969-01-01

Some of the major program at the Bio-Medical Division concerned with the fate and importance of the fission products, the radionuclides induced in the device materials, the radionuclides induced in the environment surrounding the device, and the tritium produced in Plowshare cratering events will be discussed. These programs include (1) critical unknowns in predicting organ and body burdens from radionuclides produced in cratering events; (2) the analysis with a high-resolution solid state gamma ray spectrometer of radionuclides in complex biological and environmental samples; (3) the characterization of radioactive particles from cratering detonation; (4) the biological availability to beagles, pigs and goats of radionuclides in Plowshare debris; (5) the biological availability to aquatic animals of radionuclides in Plowshare and other nuclear debris and the biological turnover of critical nuclides in specific aquatic animals; (6) the biological availability of Plowshare and other nuclear debris radionuclides to dairy cows and the transplacental transport of debris radionuclides in the dairy cow; (7) the persistence and behavior of radionuclides, particularly tritium, at sites of Plowshare and other nuclear detonations; and (8) somatic effects of Low Dose Radiation: Chromosome studies. (author)

Radiopharmaceuticals and other compounds labelled with short-lived radionuclides

CERN Document Server

Welch, Michael J

2013-01-01

Radiopharmaceuticals and Other Compounds Labelled with Short-Lived Radionuclides covers through both review and contributed articles the potential applications and developments in labeling with short-lived radionuclides whose use is restricted to institutions with accelerators. The book discusses the current and potential use of generator-produced radionuclides as well as other short-lived radionuclides, and the problems of quality control of such labeled compounds. The book is useful to nuclear medicine physicians.

Radionuclides incorporation in activated natural nanotubes

International Nuclear Information System (INIS)

Silva, Jose Parra

2016-01-01

Natural palygorskite nanotubes show suitable physical and chemical properties and characteristics to be use as potential nanosorbent and immobilization matrix for the concentration and solidification of radionuclides present in nuclear wastes. In the development process of materials with sorption properties for the incorporation and subsequent immobilization of radionuclides, the most important steps are related with the generation of active sites simultaneously to the increase of the specific surface area and suitable heat treatment to producing the structural folding. This study evaluated the determining parameters and conditions for the activation process of the natural palygorskite nanotubes aiming at the sorption of radionuclides in the nanotubes structure and subsequent evaluation of the parameters involve in the structural folding by heat treatments. The optimized results about the maximum sorption capacity of nickel in activated natural nanotubes show that these structures are apt and suitable for incorporation of radionuclides similar to nickel. By this study is verified that the optimization of the acid activation process is fundamental to improve the sorption capacities for specifics radionuclides by activated natural nanotubes. Acid activation condition optimized maintaining structural integrity was able to remove around 33.3 wt.% of magnesium cations, equivalent to 6.30·10 -4 g·mol -1 , increasing in 42.8% the specific surface area and incorporating the same molar concentration of nickel present in the liquid radioactive waste at 80 min. (author)

100 Years of radionuclide metrology

International Nuclear Information System (INIS)

Judge, S.M.; Arnold, D.; Chauvenet, B.; Collé, R.; De Felice, P.; García-Toraño, E.; Wätjen, U.

2014-01-01

The discipline of radionuclide metrology at national standards institutes started in 1913 with the certification by Curie, Rutherford and Meyer of the first primary standards of radium. In early years, radium was a valuable commodity and the aim of the standards was largely to facilitate trade. The focus later changed to providing standards for the new wide range of radionuclides, so that radioactivity could be used for healthcare and industrial applications while minimising the risk to patients, workers and the environment. National measurement institutes responded to the changing demands by developing new techniques for realising primary standards of radioactivity. Looking ahead, there are likely to be demands for standards for new radionuclides used in nuclear medicine, an expansion of the scope of the field into quantitative imaging to facilitate accurate patient dosimetry for nuclear medicine, and an increasing need for accurate standards for radioactive waste management and nuclear forensics. - Highlights: • The driving forces for the development of radionuclide metrology. • Radium standards to facilitate trade of this valuable commodity in the early years. • After 1950, focus changes to healthcare and industrial applications. • National Measurement Institutes develop new techniques, standards, and disseminate the best practice in measurement. • Challenges in nuclear medicine, radioactive waste management and nuclear forensics

Sedimentary Processes. Quantification Using Radionuclides

International Nuclear Information System (INIS)

Carroll, J.; Lerche, I.

2003-01-01

The advent of radionuclide methods in geochronology has revolutionized our understanding of modern sedimentary processes in aquatic systems. This book examines the principles of the method and its use as a quantitative tool in marine geology, with emphasis on the Pb-210 method. The assumptions and consequences of models and their behaviour are described providing the necessary background to assess the advantages and trade-offs involved when choosing a particular model for application. One of the purposes of this volume is to disentangle the influences of complicating factors, such as sediment flux variations, post-depositional diffusion of radionuclides, and bio-irrigation of sediments, to arrive at sediment ages and to properly assess the attendant data uncertainty. Environmental impacts of chemical, nuclear, or other waste material are of concern in a variety of areas around the world today. A number of relevant examples are included, demonstrating how dating models are useful for determining sources of contaminants and interpreting their influence on the environment. The book is set at a level so that an able student or professional should have no difficulty in following the procedures and methods developed. Each chapter includes case histories showing the strengths and weaknesses of a given procedure with respect to a data example. Included with this volume is the computer source code of a new generation of modelling tools based on inverse numerical analysis techniques. This first generation of the modelling tool is included, along with detailed instructions and examples for its use, in an appendix

Effects of radionuclides on non-human biota and natural ecosystem

International Nuclear Information System (INIS)

Garnier-Laplace, J.; Adam, C.; Gilbin, R.; Denison, F.; Fortin, C.; Simon, O.

2004-01-01

The need for a system of radiological protection of the environment drives regulators to urge scientists on conceptualisation of methods to demonstrate that the environment is protected against radioactive contaminants. One of the major difficulties in the implementation of ecological risk assessment for radioactive pollutants is the lack of data for wildlife chronic internal exposure to alpha or beta emitters. Situations of such chronic internal exposure at low levels are likely to cause toxic responses distinct from those observed after acute exposure at high doses because of the bioaccumulation phenomena. Biochemical mechanisms can lead to a gradual accumulation of elements present at trace level in the external medium, inducing a highly localised deposit within tissues or cells. These highly localised accumulations of radionuclides, coupling radiological and chemical toxicities, particularly for heavy elements such as actinides, may give rise to particular biological responses of a cell group, capable of causing functional or structural abnormalities at higher hierarchical levels. The assessment of these bioaccumulation phenomena investigated within the ENVIRHOM programme launched two years ago at the Institute for Radioprotection and Nuclear Safety, is primordial with regard to internal exposure to radionuclides since they increase locally both the radionuclide concentration and the biological effect of the delivered dose. Gaps of knowledge within this field constitute a strong limitation to our capability to make a reasonable risk estimate. Internal doses cannot be accurately calculated and potentially associated biological effects at any organization level remain fairly unknown. As a result, derivation of ecologically relevant and knowledge-based predicted no-effect concentrations becomes a critical issue in ERA. The scope of this paper is to illustrate the relevance of the development of a greater depth of understanding of radionuclide fate and biological

Long-term dynamics of radionuclides in semi-natural environments. Derivation of parameters and modelling. Final Report 1996-1999

Energy Technology Data Exchange (ETDEWEB)

Belli, M. [Agenzia Nazionale per la Protezione dell' Ambiente, Rome (Italy). Dipt. Stato Ambiente, Controlli e Sistemi Informativi, Unita' Interdipartimentale di Metrologia Ambientale

2000-07-01

During the Chernobyl accident large areas of semi-natural ecosystems were affected by radionuclide deposition. Meadows and forests are typical semi-natural ecosystems. Meadows are used extensively in many countries as pastures for cattle, sheep and goats, while forests are important to man since they provide wood, paper, wild berries, mushrooms, game and recreational areas. Post-Chernobyl investigations have shown that dose to man from semi-natural ecosystems is relatively greater than from agricultural systems and that this dose risk persists for the long-term. Predictive models are essential to take long-term decisions on the management of contaminated environment and to identify key processes controlling the dynamics of radionuclides inside the ecosystems. During the period following the atmospheric fallout due to the nuclear weapons testing, few models for some specific semi-natural environments were developed. The applicability of these models to a wide range of semi-natural ecosystem is questionable, because in these complex systems it is more difficult to identify general key processes and to apply to other sites models developed for one site. Studies carried out since the Chernobyl accident have increased the understanding of radionuclide behaviour in semi-natural ecosystems, especially for boreal forests and middle European meadow systems which have been extensively investigated. Data sets have been obtained which describe the distribution and the cycling of radionuclides (especially {sup 137}Cs and {sup 90}Sr) within these systems. However, predictive modelling has largely been restricted to aggregated transfer factors which provide good contamination estimates, but only for the sites from which data have been obtained directly. There was a need to develop models that can be applied to a broad variety of ecosystems. They are needed for dose estimation, countermeasure implementation and environmental management. They should give reliable estimates of the

Long-term dynamics of radionuclides in semi-natural environments. Derivation of parameters and modelling. Final Report 1996-1999

International Nuclear Information System (INIS)

Belli, M.

2000-04-01

During the Chernobyl accident large areas of semi-natural ecosystems were affected by radionuclide deposition. Meadows and forests are typical semi-natural ecosystems. Meadows are used extensively in many countries as pastures for cattle, sheep and goats, while forests are important to man since they provide wood, paper, wild berries, mushrooms, game and recreational areas. Post-Chernobyl investigations have shown that dose to man from semi-natural ecosystems is relatively greater than from agricultural systems and that this dose risk persists for the long-term. Predictive models are essential to take long-term decisions on the management of contaminated environment and to identify key processes controlling the dynamics of radionuclides inside the ecosystems. During the period following the atmospheric fallout due to the nuclear weapons testing, few models for some specific semi-natural environments were developed. The applicability of these models to a wide range of semi-natural ecosystem is questionable, because in these complex systems it is more difficult to identify general key processes and to apply to other sites models developed for one site. Studies carried out since the Chernobyl accident have increased the understanding of radionuclide behaviour in semi-natural ecosystems, especially for boreal forests and middle European meadow systems which have been extensively investigated. Data sets have been obtained which describe the distribution and the cycling of radionuclides (especially 137 Cs and 90 Sr) within these systems. However, predictive modelling has largely been restricted to aggregated transfer factors which provide good contamination estimates, but only for the sites from which data have been obtained directly. There was a need to develop models that can be applied to a broad variety of ecosystems. They are needed for dose estimation, countermeasure implementation and environmental management. They should give reliable estimates of the behaviour

Upscaling the Use of Fallout Radionuclides in Soil Erosion and Sediment Budget Investigations: Addressing the Challenge

Directory of Open Access Journals (Sweden)

D.E. Walling

2014-09-01

Full Text Available The application of fallout radionuclides in soil erosion investigations and related sediment budget studies has provided a widely used tool for improving understanding of soil erosion and sediment transfer processes. However, most studies using fallout radionuclides undertaken to date have focussed on small areas. This focus on small areas reflects both the issues addressed and practical constraints associated with sample collection and analysis. Increasing acceptance of the important role of fine sediment in degrading aquatic habitats and in the transfer and fate of nutrients and contaminants within terrestrial and fluvial systems has emphasised the need to consider larger areas and the catchment or regional scale. The need to upscale existing approaches to the use of fallout radionuclides to larger areas represents an important challenge. This contribution provides a brief review of existing and potential approaches to upscaling the use of fallout radionuclides and presents two examples where such approaches have been successfully applied. These involve a national scale assessment of soil erosion rates in England and Wales based on 137Cs measurements and an investigation of the sediment budgets of three small/intermediate-size catchments in southern Italy.

Radionuclides migration or isolation?

International Nuclear Information System (INIS)

Toulhoat, P.; Grambow, B.; Simoni, E.

2005-01-01

After 20 years of research, the chemical behaviour of actinides and fission products in nuclear waste disposal environments is much better understood. Consistent thermodynamic data have been gathered and allow much more accurate previsions. Through the considerable development of analytical spectroscopy, including time resolved laser fluorescence and X ray absorption, a better understanding of the chemical reactivity (complexation, sorption) of actinides and fission products at a molecular scale has been possible. Chemically reducing conditions are found in most selected disposal host rock formations, generally chosen for their high sorption capacity (clays); such conditions favour the chemical confinement of most radionuclides through precipitation or sorption. Low permeability host rocks participate to this confinement, as convective fluxes are lower than diffusive fluxes. The most recent performance assessment exercises have taken into account the recent progress of knowledge in the chemical evolution of the near field. They show that the dose rates at the outlet are far lower than existing recommendations for normal and most altered evolution scenarios. (authors)

21 CFR 892.5700 - Remote controlled radionuclide applicator system.

Science.gov (United States)

2010-04-01

... radionuclide applicator system. (a) Identification. A remote controlled radionuclide applicator system is an... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Remote controlled radionuclide applicator system... include patient and equipment supports, component parts, treatment planning computer programs, and...

How Solid-Electrolyte Interphase Forms in Aqueous Electrolytes.

Science.gov (United States)

Suo, Liumin; Oh, Dahyun; Lin, Yuxiao; Zhuo, Zengqing; Borodin, Oleg; Gao, Tao; Wang, Fei; Kushima, Akihiro; Wang, Ziqiang; Kim, Ho-Cheol; Qi, Yue; Yang, Wanli; Pan, Feng; Li, Ju; Xu, Kang; Wang, Chunsheng

2017-12-27

Solid-electrolyte interphase (SEI) is the key component that enables all advanced electrochemical devices, the best representative of which is Li-ion battery (LIB). It kinetically stabilizes electrolytes at potentials far beyond their thermodynamic stability limits, so that cell reactions could proceed reversibly. Its ad hoc chemistry and formation mechanism has been a topic under intensive investigation since the first commercialization of LIB 25 years ago. Traditionally SEI can only be formed in nonaqueous electrolytes. However, recent efforts successfully transplanted this concept into aqueous media, leading to significant expansion in the electrochemical stability window of aqueous electrolytes from 1.23 V to beyond 4.0 V. This not only made it possible to construct a series of high voltage/energy density aqueous LIBs with unprecedented safety, but also brought high flexibility and even "open configurations" that have been hitherto unavailable for any LIB chemistries. While this new class of aqueous electrolytes has been successfully demonstrated to support diversified battery chemistries, the chemistry and formation mechanism of the key component, an aqueous SEI, has remained virtually unknown. In this work, combining various spectroscopic, electrochemical and computational techniques, we rigorously examined this new interphase, and comprehensively characterized its chemical composition, microstructure and stability in battery environment. A dynamic picture obtained reveals how a dense and protective interphase forms on anode surface under competitive decompositions of salt anion, dissolved ambient gases and water molecule. By establishing basic laws governing the successful formation of an aqueous SEI, the in-depth understanding presented in this work will assist the efforts in tailor-designing better interphases that enable more energetic chemistries operating farther away from equilibria in aqueous media.

The contamination of the oceans by anthropogenic radionuclides

International Nuclear Information System (INIS)

Figueira, Rubens C.L.; Cunha, Ieda I.L.

1998-01-01

Several hundreds of artificial of artificial radionuclides are produced as the result of human activities, such as the applications of nuclear reactors and particle accelerators, testing of nuclear weapons and nuclear accidents. Many of these radionuclides are short-lived and decay quickly after their production, but some of them are longer-lived and are released into the environment. From the radiological point of view the most important radionuclides are cesium-137, strontium-90 and plutonium-239, due to their chemical and nuclear characteristics. The two first radioisotopes present long half life (30 and 28 years), high fission yields and chemical behaviour similar to potassium and calcium, respectively. No stable element exists for plutonium-239, that presents high radiotoxity, longh half-life (24000 years) and some marine organisms accumulate plutonium at high levels. The radionuclides introduced into marine environment undergo various physical, chemical and biological processes taking place in the sea. These processes may be due to physical, dispersion or complicated chemical and biological interactions of the radionuclides with inorganic and organic suspend matter, variety of living organism, bottom sediments, etc. The behaviour of radionuclides in the sea depends primarily on their chemical properties, but it may also be influenced by properties of interacting matrices and other environmental factors. The major route of radiation exposure of man to artificial radionuclides occuring in the marine environment is through ingestion of radiologically contamined marine organisms. This paper summarizes the main sources of contamination in the marine environment and presents an overview covering the oceanic distribution of anthropogenic radionuclides in the FAO regions. A great number of measurements of artificial radioclides have been carried out on various marine environmental samples in different oceans over the world, being cesium-137 the most widely measured

Radionuclide examination in rheumatology

International Nuclear Information System (INIS)

Streda, A.; Kolar, J.; Valesova, M.

1984-01-01

On the basis of twenty years of experience with the use of radionuclides in bone and articular rheumatic diseases indications for such examinations are summed up. The main advantage of the use of radionuclide methods is that they bring forward early diagnosis of tissue reconstruction which can thus be detected at the stage of microstructural changes. They also provide earlier and more reliable detection of the degree of the pathological process than is provided by X-ray examination. In some cases scintiscan may also be found useful as a method for following up the results of treatment of rheumatic diseases. (author)

Confinement and migration of radionuclides in deep geological disposal; Confinement et migration des radionucleides en stockage geologique profond

Energy Technology Data Exchange (ETDEWEB)

Poinssot, Ch

2007-07-15

Disposing high level nuclear waste in deep disposal repository requires to understand and to model the evolution of the different repository components as well as radionuclides migration on time-frame which are well beyond the time accessible to experiments. In particular, robust and predictive models are a key element to assess the long term safety and their reliability must rely on a accurate description of the actual processes. Within this framework, this report synthesizes the work performed by Ch. Poinssot and has been prepared for the defense of his HDR (French university degree to Manage Research). These works are focused on two main areas which are (i) the long term evolution of spent nuclear fuel and the development of radionuclide source terms models, and (ii) the migration of radionuclides in natural environment. (author)

Solubility limited radionuclide transport through geologic media

International Nuclear Information System (INIS)

Muraoka, Susumu; Iwamoto, Fumio; Pigford, T.H.

1980-11-01

Prior analyses for the migration of radionuclides neglect solubility limits of resolved radionuclide in geologic media. But actually some of the actinides may appear in chemical forms of very low solubility. In the present report we have proposed the migration model with no decay parents in which concentration of radionuclide is limited in concentration of solubility in ground water. In addition, the analytical solutions of the space-time-dependent concentration are presented in the case of step release, band release and exponential release. (author)

Radionuclide determination of right and left ventricular stroke volumes

Energy Technology Data Exchange (ETDEWEB)

Shen, Wei Feng; Roubin, G S; Choong, C Y.P.; Harris, P J; Flether, P J; Kelly, D T; Uren, R F; Hutton, B F

1985-03-01

The relationship between radionuclide and thermodilution measurement of stroke volumes (SV) was investigated in 30 patients without valvular regurgitation or intracardiac shunt (group A) at rest and during exercise. Both attenuated radionuclide right ventricular (RV) and left ventricular (LV) SV measurements correlated well with the SV determined by the thermodilution method (r = 0.87 and r = 0.93, all P < 0.001). The reliability of the radionuclide method to estimate SV was evaluated prospectively in two additional groups of patients. In 11 patients without valvular regurgitation or intracardiac shunt (group B) the radionuclide RVSV and LVSV closely approximated to thermodilution SV at rest and during exercise. In 15 patients with aortic regurgitation (group C) the radionuclide stroke volume ratio correlated well with the angiographic regurgitant fraction. Thus, both RVSV and LVSV and the severity of aortic regurgitation can be reliably measured with gated radionuclide ventriculography.

Methods for determining radionuclide retardation factors: status report

International Nuclear Information System (INIS)

Relyea, J.F.; Serne, R.J.; Rai, D.

1980-04-01

This report identifies a number of mechanisms that retard radionuclide migration, and describes the static and dynamic methods that are used to study such retardation phenomena. Both static and dynamic methods are needed for reliable safety assessments of underground nuclear-waste repositories. This report also evaluates the extent to which the two methods may be used to diagnose radionuclide migration through various types of geologic media, among them unconsolidated, crushed, intact, and fractured rocks. Adsorption is one mechanism that can control radionuclide concentrations in solution and therefore impede radionuclide migration. Other mechanisms that control a solution's radionuclide concentration and radionuclide migration are precipitation of hydroxides and oxides, oxidation-reduction reactions, and the formation of minerals that might include the radionuclide as a structural element. The retardation mechanisms mentioned above are controlled by such factors as surface area, cation exchange capacity, solution pH, chemical composition of the rock and of the solution, oxidation-reduction potential, and radionuclide concentration. Rocks and ground waters used in determining retardation factors should represent the expected equilibrium conditions in the geologic system under investigation. Static test methods can be used to rapidly screen the effects of the factors mentioned above. Dynamic (or column) testing, is needed to assess the effects of hydrodynamics and the interaction of hydrodynamics with the other important parameters. This paper proposes both a standard method for conducting batch Kd determinations, and a standard format for organizing and reporting data. Dynamic testing methods are not presently developed to the point that a standard methodology can be proposed. Normal procedures are outlined for column experimentation and the data that are needed to analyze a column experiment are identified

Environmental dispersion of long-lived radionuclides in the geosphere and biosphere

International Nuclear Information System (INIS)

Myttenaere, C.; Avogadro, A.; Murray, C.N.

1984-01-01

Knowledge of the migration of radionuclides in the terrestrial environment is one of the key elements in assessment of the risk resulting from potential or actual releases from nuclear facilities. Among the various radionuclides arising from the nuclear fuel cycle, long-lived fission products and actinides are of particular concern for the different disposal options considered for radioactive wastes. Current knowledge of the processes that are responsible for their migration through different compartments of the environment (geosphere and biosphere) is reviewed. Migration in the geosphere is governed by a number of different mechanisms that have a wide range of reaction rates. Certain processes may be identified that control short-term behaviour and others long term. In assessing these processes, which relate to the interaction between solid and liquid phases, special attention is paid to the time-scale as well as the dynamic nature of the controlling processes. The current state of knowledge and the major research efforts under way concerning the predominant processes identified in different geological disposal options are reviewed. Various mechanisms control the behaviour of long-lived radionuclides and actinides in the soil and their migration in the biosphere. Regarding the biological uptake, particular attention is drawn to the 'ageing' phenomena and their consequences on radioactivity transfer in the different food chains. Similarities in the biogeochemical properties of natural and man-made elements that could further our understanding of the long-term behaviour of radionuclides are discussed. Consequently, all these considerations justify study of the biogeochemical aspects of the transfer of radioactivity in the environment. In the actual state of knowledge the uncertainties in the parameters used in the models may lead to difficulty in long-term dose estimation. Assessment of the dose received by man appears to be more strongly limited by the quality of

Research progess on treatment of cancer with targeted radionuclide therapy

International Nuclear Information System (INIS)

Luo Jiawen; Zhang Caixia

2008-01-01

The new development and situation of targeted radionuclide therapy in oncology is described, which include radioimmunotherapy, peptide receptor radionuclide therapy, gene therapy and radionuclide labled chemotherapeutics therapy. The application research on labled carrier of those therapy is emphasized. Meanwhile, the research progess of indomethacin and its combined with targeted radionuclide therapy is also described. (authors)

Fire fighting in a radionuclide laboratory

International Nuclear Information System (INIS)

Wenzel, H.

1991-01-01

A fire-brigade was called to a laboratory which held a handling licence for the radionuclides C-14, T, P-32, Se-75, Mo-99, and S-35. The fire-brigade was unaware of a release of radionuclides. Therefore they used respiratory equipment, and all persons present were subsequently examined for contamination. (DG) [de

A review of aqueous foam in microscale.

Science.gov (United States)

Anazadehsayed, Abdolhamid; Rezaee, Nastaran; Naser, Jamal; Nguyen, Anh V

2018-06-01

In recent years, significant progress has been achieved in the study of aqueous foams. Having said this, a better understanding of foam physics requires a deeper and profound study of foam elements. This paper reviews the studies in the microscale of aqueous foams. The elements of aqueous foams are interior Plateau borders, exterior Plateau borders, nodes, and films. Furthermore, these elements' contribution to the drainage of foam and hydraulic resistance are studied. The Marangoni phenomena that can happen in aqueous foams are listed as Marangoni recirculation in the transition region, Marangoni-driven flow from Plateau border towards the film in the foam fractionation process, and Marangoni flow caused by exposure of foam containing photosurfactants under UV. Then, the flow analysis of combined elements of foam such as PB-film along with Marangoni flow and PB-node are studied. Next, we contrast the behavior of foams in different conditions. These various conditions can be perturbation in the foam structure caused by injected water droplets or waves or using a non-Newtonian fluid to make the foam. Further review is about the effect of oil droplets and particles on the characteristics of foam such as drainage, stability and interfacial mobility. Copyright © 2018 Elsevier B.V. All rights reserved.

Permissible annual depositions and radionuclide concentrations in air

International Nuclear Information System (INIS)

Belyaev, V.A.; Golovko, M.Yu.

1993-01-01

It is established that it necessary to take into account the other ways of radionuclide intake apart from the inhalation one when determining the standards for radionuclide contamination of the atmospheric air. Whereby it is proposed to standardize annual depositions rather than permissible concentration in the atmospheric air for the ways related to radionuclide releases on the ground surface, which is explained by ambiguity of their dry deposition rate from the air. Formulae and results of calculation of standard characteristics are presented. The permissible radionuclide depositions, related to the intake through food chains are calculated with account for diet diversity, agroclimatic and phenological parameters in different regions of the country

Radionuclide transport in a single fissure

International Nuclear Information System (INIS)

Eriksen, T.E.

1988-12-01

The study of radionuclide migration through rock is currently of great interest due to its relevance to the possible escape paths into the biosphere of radionuclides released from high level radioactive wastes burried in deep geological repositories. While water will provide the vehicle for transportation, interaction with geological material may greatly influence the radionuclide movement relative that of water. A flow system for laboratory studies of radionuclide transport in natural fissures in granitic rock under reducing conditions is described. The system based on the use of synthetic ground water equilibrated with granitic rock in a well sealed system, allow experiments to be carried out at -240 mV reduction potential. In flow experiments with technetium the retardation was found to be dependent on the method used for reducing TcO 4 - . The preparation of the tracer solutions is crucial, as some of the redox-reactions may be very slow. The dynamics of the Tc(VII) reduction and also speciation need to be carried out in separate experiments. (4 illustrations, 5 tables)

Radionuclide therapy practice and facilities in Europe

International Nuclear Information System (INIS)

Hoefnagel, C.A.; Clarke, S.E.M.; Fischer, M.; Chatal, J.F.; Lewington, V.J.; Nilsson, S.; Troncone, L.; Vieira, M.R.

1999-01-01

Using a questionnaire the EANM Task Group Radionuclide Therapy in 1993 collected data on the current practice of radionuclide therapy in European countries. Subsequently, at the request of the EANM Executive Committee, the EANM Radionuclide Therapy Committee has made an inventory of the distribution of facilities for radionuclide therapy and undertaken an assessment of the total number of patients treated throughout Europe and of the types of treatment provides, with the aim of supporting the development of policy to adjust the available capacity to the needs by the year 2000. For this purpose, a second, more detailed questionnaire was sent out the members and national advisors of the Committee (see below), who gathered the data for each country that was a member of the EANM at the time. It is concluded that a wide bariation in therapy practice exists across Europe, particularly in the utilisation of radionuclide therapy, the requirement and availability of proper isolation facilities and the background training of those undertaking therapy. More uniform guidelines and legislation are required, although changes in legislation may have a significant impact in some countries. Although there is wide variation in the therapies used in each country, one the whole it appears that there is an underutilisation of nuclear medicine as a therapeutic modality. A rapidly increasing role may be expected, in particular for oncological indications requiring high-dose radionuclide treatment. Therefore there is an urgent need for a greater number of isolation beds in dedicated centers throughout Europe

Trace Metals in Groundwater and the Vadose Zone Calcite: In Situ Containment and Stabilization of Strontium-90 and Other Divalent Metals and Radionuclides at Arid West DOE

International Nuclear Information System (INIS)

Smith, Robert W.

2004-01-01

Radionuclide and metal contaminants such as strontium-90 are present beneath U.S. Department of Energy (DOE) lands in both the groundwater (e.g., 100-N area at Hanford, WA) and vadose zone (e.g., Idaho Nuclear Technology and Engineering Center at the Idaho National Engineering and Environmental Laboratory). In situ containment and stabilization of these contaminants is a cost-effective treatment strategy. However, implementing in situ containment and stabilization approaches requires definition of the mechanisms that control contaminant sequestration. We are investigating the in situ immobilization of radionuclides or contaminant metals (e.g., strontium-90) by their facilitated co-precipitation with calcium carbonate in groundwater and vadose zone systems. Our facilitated approach, shown schematically in Figure 1, relies upon the hydrolysis of introduced urea to cause the acceleration of calcium carbonate precipitation (and trace metal co-precipitation) by increasing pH and alkalinity. Subsurface urea hydrolysis is catalyzed by the urease enzyme, which may be either introduced with the urea or produced in situ by ubiquitous subsurface urea hydrolyzing microorganisms. Because the precipitation process tends to be irreversible and many western aquifers are saturated with respect to calcite, the co-precipitated metals and radionuclides will be effectively removed from the aqueous phase over the long-term. Another advantage of the ureolysis approach is that the ammonium ions produced by the reaction can exchange with radionuclides sorbed to subsurface minerals, thereby enhancing the availability of the radionuclides for re-capture in a more stable solid phase (co-precipitation rather than adsorption)

The potential of coconut fibers in raw and treated forms to remove {sup 241}Am from aqueous solutions

Energy Technology Data Exchange (ETDEWEB)

Fonseca, Heverton C.O.; Jesus, Nella N.M. de; Nobre, Vanessa B.; Potiens Junior, Ademar; Sakata, Solange K., E-mail: sksakata@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2013-07-01

In the Radioactive Waste Management (GRR) at the Nuclear and Energy Research Institute (IPEN/CNEN-SP) vegetal biomass has been studied as adsorbent to remove radioisotopes from radioactive liquid wastes as part of the radioactive waste treatment program. In this work coconuts fiber was evaluate as biosorbent to remove {sup 241}Am from aqueous solutions and many different parameters were studied such as particle size (35 and 80 mesh) and contact time (between 5 and 60 minutes). In order to evaluate if the treated biomass could remove more {sup 241}Am the experiments were also performed using raw biomass and treated with H{sub 2}O{sub 2} in basic conditions. When the experiment was carried out using raw coconuts fiber with 80 mesh, neutral conditions after 5 minutes of contact time 99% of the radionuclide was removed from the aqueous solution. This result shows the potential of this biomass to remove {sup 241}Am from radioactive liquid wastes. (author)

Surface diffusion of sorbed radionuclides

International Nuclear Information System (INIS)

Berry, J.A.; Bond, K.A.

1991-01-01

Surface diffusion has in the past been invoked to explain rates of radionuclide migration which were greater than those predicted. Results were generally open to interpretation but the possible existence of surface diffusion, whereby sorbed radionuclides could potentially migrate at much enhanced rates, necessitated investigation. In this work through-diffusion experiments have shown that although surface diffusion does exist for some nuclides, the magnitude of the phenomenon is not sufficient to affect repository safety assessment modelling. (author)

DNA damage induced by radionuclide internal irradiation

International Nuclear Information System (INIS)

Cui Fengmei; Zhao Jingyong; Hong Chengjiao; Lao Qinhua; Wang Liuyi; Yang Shuqin

2004-01-01

Objective: To study the DNA damage of peripheral blood mononuclear cell (PBMC) in rats exposed to radionuclide internal irradiation. Methods: The radionuclides were injected into the rats and single cell get electrophoresis (SCGE) was performed to detect the length of DNA migration in the rat PBMC. Results: DNA migration in the rat PBMC increased with accumulative dose or dose-rate. It showed good relationship of dose vs. response and of dose-rate vs. response, both relationship could be described as linear models. Conclusion: Radionuclide internal irradiation could cause DNA damage in rat PBMC. (authors)

Radionuclide Basics: Iodine

Science.gov (United States)

... Centers Radiation Protection Contact Us Share Radionuclide Basics: Iodine Iodine (chemical symbol I) is a chemical element. ... in the environment Iodine sources Iodine and health Iodine in the Environment All 37 isotopes of iodine ...

40 CFR 141.66 - Maximum contaminant levels for radionuclides.

Science.gov (United States)

2010-07-01

... beta particle and photon radioactivity from man-made radionuclides in drinking water must not produce.../year). (2) Except for the radionuclides listed in table A, the concentration of man-made radionuclides... may make this technology too complex for small surface water systems. e Removal efficiencies can vary...

Preparation of modified polymer- Alumino silicate composite and their application in removal of some radionuclides from aqueous solutions

International Nuclear Information System (INIS)

El- Masry, E.H.

2012-01-01

Ion exchange is one of the most common and effective treatment methods for radioactive liquid waste. This technique is well developed and has been employed for many years in both the nuclear industry and in other industries. In this thesis polyacrylamide- zeolite and polyacrylamide- bentonite composites were prepared and characterized using advanced analytical techniques. The prepared materials were used as composite ion exchangers for removal of Cesium, Cobalt and Strontium ions from simulated waste solution. Effect of ph of the medium on the removal of aforementioned ions was investigated. The sorption kinetic was studied and the data were analyzed by different kinetic models which rivaled that the mechanism of the sorption processes is mainly controlled by pseudo-second order reaction, and particle diffusion might be involved in the sorption processes. The values of diffusion coefficient of the three metal ions were calculated and suggested that chemisorption was the predominated sorption mechanism. Several isotherm models were applied for the sorption, and thermodynamic parameters were determined. The positive values of enthalpy change, δH, for the three metal ions confirmed the endothermic nature of the sorption processes. The results indicated that the prepared materials can be used as efficient ion exchange materials for the removal of cesium, cobalt and strontium ions from simulated waste solution. In the present study, immobilization of polyacrylamide- zeolite and/ or polyacrylamide- bentonite composites loaded with cesium, cobalt and/or strontium radionuclides with Ordinary Portland Cement (OPC) has been carried out. Several factors affecting the characteristics of the final solidified waste product towards safe disposal such as mechanical strength and leaching behavior of the radioisotopes have been studied. The obtained results showed that the presence of polyacrylamide- zeolite and/ or polyacrylamide- bentonite composites in the cemented wastes

Presence of radionuclides in sludge from conventional drinking water treatment plants. A review

International Nuclear Information System (INIS)

Fonollosa, E.; Nieto, A.; Peñalver, A.; Aguilar, C.; Borrull, F.

2015-01-01

The analysis of sludge samples generated during water treatment processes show that different radioisotopes of uranium, thorium and radium, among others can accumulate in that kind of samples, even the good removal rates obtained in the aqueous phase (by comparison of influent and effluent water concentrations). Inconsequence, drinking water treatment plants are included in the group of Naturally Occurring Radioactive Material (NORM) industries. The accumulation of radionuclides can be a serious problem especially when this sludge is going to be reused, so more exhaustive information is required to prevent the possible radiological impact of these samples in the environment and also on the people. The main aim of this review is to outline the current situation regarding the different studies reported in the literature up to date focused on the analysis of the radiological content of these sludge samples from drinking water treatment plants. In this sense, special attention is given to the recent approaches for their determination. Another important aim is to discuss about the final disposal of these samples and in this regard, sludge reuse (including for example direct agricultural application or also as building materials) are together with landfilling the main reported strategies. - Highlights: • In this review we discuss the methods used to determine radionuclides in sludge from DWTP. • We summarize the different coagulants used and the consequences in the characteristics of the sludge. • We mention different possibilities to reuse the sludge generated in DWTPs

Radiotolerance of phosphatases of a Serratia sp.: potential for the use of this organism in the biomineralization of wastes containing radionuclides.

Science.gov (United States)

Paterson-Beedle, M; Jeong, B C; Lee, C H; Jee, K Y; Kim, W H; Renshaw, J C; Macaskie, L E

2012-08-01

Aqueous wastes from nuclear fuel reprocessing present special problems of radiotoxicity of the active species. Cells of Serratia sp. were found previously to accumulate high levels of hydrogen uranyl phosphate (HUP) via the activity of a phosphatase enzyme. Uranium is of relatively low radiotoxicity whereas radionuclide fission products such as (90)Sr and (137)Cs are highly radiotoxic. These radionuclides can be co-crystallized, held within the bio-HUP "host" lattice on the bacterial cells and thereby removed from contaminated solution, depending on continued phosphatase activity. Radiostability tests using a commercial (60)Co γ-source showed that while cell viability and activity of purified phosphatase were lost within a few hours on irradiation, whole-cell phosphatase retained 80% of the initial activity, even after loss of cell culturability, which was increased to 100% by the incorporation of mercaptoethanol as an example radioprotectant, beyond an accumulated dose of >1.3 MGy. Using this co-crystallization approach (without mercaptoethanol) (137)Cs(+) and (85)Sr(2+) were removed from a simulated waste selectively against a 33-fold excess of Na(+). Copyright © 2012 Wiley Periodicals, Inc.

Choice of radionuclide for antibody labelling: new perspectives

International Nuclear Information System (INIS)

Hazra, D.K.; Dass, S.

1983-01-01

The expanding horizons of labelled antibody techniques in diagnostic imaging or assay, therapy and research and the availabilities of monoclonal antibodies is resulting in a demand for suitable radionuclides as antibody labels. An outline is given of the different criteria for choosing an appropriate radionuclide for labelling an antibody depending on its particular field of use. The requirements of procedures for firmly linking radionuclides to antibodies are also given. (U.K.)

Emissions of the corrosion radionuclides in an atmosphere

International Nuclear Information System (INIS)

Vardanyan, M.

2010-01-01

In area of Armenian nuclear power plant location, in atmospheric air in majority of cases log two technogenic radionuclides: l 37 C s and 9 0 S r. Presence of these radionuclides basically is caused by global fall out (consequences of tests of the nuclear weapon and Chernobyl NPP accident), whose contribution to the contents of these radionuclides in atmosphere is incomparably greater, than emissions from the NPP. However there are some cases when in an atmosphere are registered the technogenic radionuclides, caused by emissions from NPP. In the present work such case is considered. Gas-aerosol releases of NPP in the atmosphere are carefully purified by means of various high-efficiency filters and gas-cleaning systems. Nevertheless, one should forecast and measure, the possible impact of these releases on the environment in the regions surrounding the NPP. Radioactive releases of the Armenian NPP (ANPP) contain the set of radionuclides characteristic for NPPs of this type. They may be divided into three groups: 1 31 I , 1 37 C s, 1 34 C s, 9 0 S r and 8 9 S r fission fragments, isotopes of noble gases krypton and xenon and other radionuclides; corrosion originated radionuclides: 6 0 C o, 1 10m A g, 5 4 M n, 5 l C r and others; activation products of the heat-transfer agent itself. It should be noted that the amount of radioactive materials released in the environment by the ANPP during the whole period of its operation was much lower than the admissible quantities specified in the corresponding legal documents (RSN, NPPSP) acting in Armenia, which are practically identical to the internationally accepted norms. The amounts of releases and their radionuclides composition for the ANPP are given

An introduction to radiation induced degradation of biological molecules in aqueous solutions

International Nuclear Information System (INIS)

Lal, Manohar

1991-01-01

Radiation chemistry of aqueous systems is the chemistry of H, OH, e aq - , H 3 O + and H 2 O * formed when a solute in aqueous solutions is exposed to ionising radiation. The pulse radiolysis technique has helped in the production, the detection and understanding of the reactions of primary species with solutes. A great deal of data on radiation biochemical studies e.g. degradation of DNA, its constituents and their protection, radiation protection and sensitisation, generation of superoxide ion and their reactions has already been reported but a great deal still needs to be done for the understanding of radiation biology. (author). 12 refs

Chemical behavior of long-lived radionuclides in the marine environment

International Nuclear Information System (INIS)

Edgington, D.N.; Nelson, D.M.

1983-01-01

Measurements of long-lived radionuclides in the marine environment have provided a wealth of information regarding the physical, biological, and chemical processes which control the behavior of these and many other pollutants in the oceans. Their value as tracers for the dispersion, transport, and fate of pollutants in the oceans is largely dependent on the chemical properties of each individual radioelement. Differences in these properties, particularly in relation to their interaction with biotic or abiotic particulate matter, result in the separation of parent-daughter radioisotopes in the natural radioelement series or in changes in the ratios of fission and activation products. Such differences have provided the means to provide time scales for a variey of transport processes and to determine sedimentation rates. The properties of these radionuclides in the oceans can, in general, be predicted from the chemical properties of the stable elements. For those elements such as plutonium, for which there are no naturally-occurring stable isotopes, studies of their distribution in the oceans have provided a new important understanding of their chemical behavior. This behavior has not always agreed with what would have been predicted from laboratory studies carried out at far higher concentrations. Differences between observed distributions and laboratory predictions have highlighted the importance of correct experimental conditions in order to avoid confusing experimental artifacts. The interaction of radionuclides with particles in the oceans and marine sediments can be described in terms of simple ion exchange or adsorption equilibria

Bayesian statistics in radionuclide metrology: measurement of a decaying source

International Nuclear Information System (INIS)

Bochud, F. O.; Bailat, C.J.; Laedermann, J.P.

2007-01-01

The most intuitive way of defining a probability is perhaps through the frequency at which it appears when a large number of trials are realized in identical conditions. The probability derived from the obtained histogram characterizes the so-called frequentist or conventional statistical approach. In this sense, probability is defined as a physical property of the observed system. By contrast, in Bayesian statistics, a probability is not a physical property or a directly observable quantity, but a degree of belief or an element of inference. The goal of this paper is to show how Bayesian statistics can be used in radionuclide metrology and what its advantages and disadvantages are compared with conventional statistics. This is performed through the example of an yttrium-90 source typically encountered in environmental surveillance measurement. Because of the very low activity of this kind of source and the small half-life of the radionuclide, this measurement takes several days, during which the source decays significantly. Several methods are proposed to compute simultaneously the number of unstable nuclei at a given reference time, the decay constant and the background. Asymptotically, all approaches give the same result. However, Bayesian statistics produces coherent estimates and confidence intervals in a much smaller number of measurements. Apart from the conceptual understanding of statistics, the main difficulty that could deter radionuclide metrologists from using Bayesian statistics is the complexity of the computation. (authors)

Stochastic analysis of radionuclide migration in saturated-unsaturated soils

International Nuclear Information System (INIS)

Kawanishi, Moto

1988-01-01

In Japan, LLRW (low level radioactive wastes) generated from nuclear power plants shall be started to store concentrically in the Shimokita site from 1990, and those could be transformed into land disposal if the positive safety is confirmed. Therefore, it is hoped that the safety assessment method shall be successed for the land disposal of LLRW. In this study, a stochastic model to analyze the radionuclide migration in saturated-unsaturated soils was constructed. The principal results are summarized as follows. 1) We presented a generalized idea for the modeling of the radionuclide migration in saturated-unsaturated soils as an advective-dispersion phenomena followed by the decay of radionuclides and those adsorption/desorption in soils. 2) Based on the radionuclide migration model mentioned above, we developed a stochastic analysis model on radionuclide migration in saturated-unsaturated soils. 3) From the comparison between the simulated results and the exact solution on a few simple one-dimensional advective-dispersion problems of radionuclides, the good validity of this model was confirmed. 4) From the comparison between the simulated results by this model and the experimental results of radionuclide migration in a one-dimensional unsaturated soil column with rainfall, the good applicability was shown. 5) As the stochastic model such as this has several advantages that it is easily able to represent the image of physical phenomena and has basically no numerical dissipation, this model should be more applicable to the analysis of the complicated radionuclide migration in saturated-unsaturated soils. (author)

Preparation of Radiopharmaceuticals Labeled with Metal Radionuclides

Energy Technology Data Exchange (ETDEWEB)

Welch, M.J.

2012-02-16

The overall goal of this project was to develop methods for the production of metal-based radionuclides, to develop metal-based radiopharmaceuticals and in a limited number of cases, to translate these agents to the clinical situation. Initial work concentrated on the application of the radionuclides of Cu, Cu-60, Cu-61 and Cu-64, as well as application of Ga-68 radiopharmaceuticals. Initially Cu-64 was produced at the Missouri University Research Reactor and experiments carried out at Washington University. A limited number of studies were carried out utilizing Cu-62, a generator produced radionuclide produced by Mallinckrodt Inc. (now Covidien). In these studies, copper-62-labeled pyruvaldehyde Bis(N{sup 4}-methylthiosemicarbazonato)-copper(II) was studied as an agent for cerebral myocardial perfusion. A remote system for the production of this radiopharmaceutical was developed and a limited number of patient studies carried out with this agent. Various other copper radiopharmaceuticals were investigated, these included copper labeled blood imaging agents as well as Cu-64 labeled antibodies. Cu-64 labeled antibodies targeting colon cancer were translated to the human situation. Cu-64 was also used to label peptides (Cu-64 octriatide) and this is one of the first applications of a peptide radiolabeled with a positron emitting metal radionuclide. Investigations were then pursued on the preparation of the copper radionuclides on a small biomedical cyclotron. A system for the production of high specific activity Cu-64 was developed and initially the Cu-64 was utilized to study the hypoxic imaging agent Cu-64 ATSM. Utilizing the same target system, other positron emitting metal radionuclides were produced, these were Y-86 and Ga-66. Radiopharmaceuticals were labeled utilizing both of these radionuclides. Many studies were carried out in animal models on the uptake of Cu-ATSM in hypoxic tissue. The hypothesis is that Cu-ATSM retention in vivo is dependent upon the

Radionuclide transfer onto ground surface in surface water flow, 1

International Nuclear Information System (INIS)

Mukai, Masayuki; Takebe, Shinichi; Komiya, Tomokazu; Kamiyama, Hideo

1991-07-01

Radionuclides migration in ground surface water flow is considered to be one of the important path way in the scenario for environmental migration of radionuclides leaked from low level radioactive waste repository. Simulating the slightly sloped surface on which contaminated solution is flowing downward, testing for radionuclide migration on ground surface had been started. As it's first step, an experiment was carried out under the condition of restricted infiltration in order to elucidate the adsorption behavior of radionuclides onto the loamy soil surface in related with hydraulic conditions. Radionuclides concentration change in effluent solution with time and a concentration distribution of radionuclides adsorbed on the ground surface were obtained from several experimental conditions combining the rate and the duration time of the water flow. The radionuclides concentration in the effluent solution was nearly constant during each experimental period, and was reduced under the condition of lower flow rate. The surface distribution of radionuclides concentration showed two distinctive regions. The one was near the inlet vessel where the concentration was promptly reducing, and the other was following the former where the concentration was nearly constant. The characteristic surface distribution of radionuclides concentration can be explained by a two dimensional diffusion model with a first order adsorption reaction, based on the advection of flow rate distribution in perpendicular direction. (author)

Extreme radionuclide accumulation on alpine glaciers in cryoconites

International Nuclear Information System (INIS)

Lettner, H.; Wilflinger, T.; Hubmer, A.K.; Bossew, P.

2008-01-01

Full text: Under environmental conditions when radionuclide fallout will not be diluted by media like soil or water, radionuclides deposited may accumulate to unusual high activities. On glacier surfaces conditions as such exist for aerosols and airborne dust deposited with anthropogenic and natural radionuclides attached on their surfaces. In the course of agglomeration processes initiated by melting and redistribution, these particles may concentrate in small depressions, ice pockets, ablation edges etc. and form substances called cryoconites ('ice dust'). As there is no other matrix than the original aerosol particles, cryoconites are a sink for radionuclides and airborne pollutants and their activity levels are among the highest produced by natural processes observed in environmental media. 137 Cs activities found on glaciers in the Austrian alps are between 255 and 136.000 Bq/kg and predominantly derived from Chernobyl, but also from global fallout. Further anthropogenic radionuclides detected are 134 Cs, 90 Sr, 238,239+240 Pu, 241 Am, 125 Sb, 154 Eu, 60 Co and 207 Bi. In combination with the naturally occurring radionuclides 7 Be and 210 Pb and isotopic ratios such as 134 Cs/ 137 Cs, identification and discrimination of the sources, the nuclear weapon tests and the Chernobyl fallout, can be carried out. (author)

Radionuclide X-ray fluorescence analysis

International Nuclear Information System (INIS)

Cechak, T.

1994-01-01

The author's achievements in the title field are summarized and discussed. The following topics are dealt with: (i) principles of radionuclide X-ray fluorescence analysis; (ii) mathematical methods in X-ray fluorescence analysis; (iii) Ross differential filters; (iv) application of radionuclide X-ray fluorescence analysis in the coal industry (with emphasis on the determination of the ash content, sulfur content, and arsenic content of coal); and (v) evaluation of the X-ray fluorescence analyzer from the radiological safety point of view. (P.A.)

Radionuclide generators for biomedical applications

International Nuclear Information System (INIS)

Finn, R.D.; Molinski, V.J.; Hupf, H.B.; Kramer, H.

1983-10-01

This document reviews the chemical literature of those radionuclide generators that have gained or appear to possess utility in medical imaging. The text represents a conscientious effort to peruse the scientific literature through 1980. The intent of this work is to provide a reference point for the investigator who is interested in the development of a particular generator system and the refinements which have been reported. Moreover, the incorporation of the particular daughter radionuclide into a suitable radiodiagnostic agent is presented

Transfer into the biosphere of radionuclides released from deep storage of radioactive wastes. Bibliographical study

International Nuclear Information System (INIS)

Guedon, V.; Siclet, F.

1995-03-01

Most countries with civilian nuclear programs today are encountering difficulty in implementing a nuclear waste management policy that is both technically safe in the long term and accepted by the public. To meet both criteria, the solution most generally envisaged is deep storage either of untreated spent nuclear fuel or of highly radioactive wastes resulting from reprocessing. In order to predict the potential impact of such storage on man, one needs to understand the path followed by radionuclides in the geosphere, and later in the biosphere. Given the time scales involved and the critical nature of the elements concerned, it is indispensable to turn to mathematical modeling of the phenomena. This, however, does not preclude the essential need for in-depth knowledge of the phenomena and of the physico-chemical characteristics of radionuclides. This report presents what is hoped to be a complete inventory of the radionuclides contained in ''high level'' wastes (categories B AND C). The elements concerned in studies on deep storage are essentially long-life radionuclides (both actinides and certain fission and activation products). Their physico-chemical characteristics and their behavior in various ecological compartments are examined. Bibliographical data bearing on: solubility (in an oxidizing, reducing medium), distribution factors (water/rock-sediment-soil), concentration and transfer factors (in aquatic and terrestrial mediums), dose conversion factors (in the case of internal and external irradiation), principal paths of exposure for each radionuclide studied, are presented in this report. Initial results from international projects to model what happens to radionuclides in the biosphere are also presented. In general, they are optimistic as to the future, but nonetheless point to a need to improve the conceptual base of the models, to ensure that all major phenomena and processes are taken into consideration and to examine any possible amplification

The behaviour of radionuclides in the processing of rare earth minerals

International Nuclear Information System (INIS)

Hart, K.P.; Brown, S.A.; Levins, D.M.

1993-01-01

In recent years the presence of thorium in monazites has been seen as significant economic obstacle to utilisation of this resource. In particular, the environmental problems encountered with disposal of the radioactive wastes in France, China and Malaysia have led to a decline in the use of monazite as rare earth feed stock. The price of monazite has consequently fallen from $800 per tonne to the present price of $250 per tonne and significant quantities of monazite are now being ploughed back into the tailings from mineral sands processing. The environmental problems experienced overseas with disposal of monazite wastes have resulted mainly from poor waste disposal practices and/or inappropriate siting of plants rather than an insoluble waste management problem. Nevertheless, it is important to understand the behaviour of radionuclides during the processing of monazite so that appropriate measures can be undertaken to minimise the environmental impact. This paper discusses the potential hazards associated with radionuclides in the thorium and uranium decay chain. The partitioning of radioactivity during the processing of monazite is described and results of experimental work are presented on the behaviour of radionuclides during the chemical processing of beach sand monazite and the supergene monazite from Mt Weld which contains far lower levels of thorium and uranium. 5 refs., 7 tabs., 2 figs

Structure and transport of aqueous electrolytes: From simple halides to radionuclide ions

Energy Technology Data Exchange (ETDEWEB)

Hartkamp, Remco, E-mail: hartkamp@mit.edu; Coasne, Benoit, E-mail: benoit.coasne@enscm.fr [Institut Charles Gerhardt Montpellier, CNRS (UMR 5253), Université Montpellier 2, ENSCM, 8 rue de l’Ecole Normale, 34296 Montpellier Cedex 05 (France); MultiScale Material Science for Energy and Environment, CNRS/MIT (UMI 3466), Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States)

2014-09-28

Molecular simulations are used to compare the structure and dynamics of conventional and radioactive aqueous electrolytes: chloride solutions with sodium, potassium, cesium, calcium, and strontium. The study of Cs{sup +} and Sr{sup 2+} is important because these radioactive ions can be extremely harmful and are often confused by living organisms for K{sup +} and Ca{sup 2+}, respectively. Na{sup +}, Ca{sup 2+}, and Sr{sup 2+} are strongly bonded to their hydration shell because of their large charge density. We find that the water molecules in the first hydration shell around Na{sup +} form hydrogen bonds between each other, whereas molecules in the first hydration shell around Ca{sup 2+} and Sr{sup 2+} predominantly form hydrogen bonds with water molecules in the second shell. In contrast to these three ions, K{sup +} and Cs{sup +} have low charge densities so that they are weakly bonded to their hydration shell. Overall, the structural differences between Ca{sup 2+} and Sr{sup 2+} are small, but the difference between their coordination numbers relative to their surface areas could potentially be used to separate these ions. Moreover, the different decays of the velocity-autocorrelation functions corresponding to these ions indicates that the difference in mass could be used to separate these cations. In this work, we also propose a new definition of the pairing time that is easy to calculate and of physical significance regardless of the problem at hand.

2014 LANL Radionuclide Air Emissions Report

Energy Technology Data Exchange (ETDEWEB)

Fuehne, David Patrick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2015-07-21

This report describes the emissions of airborne radionuclides from operations at Los Alamos National Laboratory (LANL) for calendar year 2014, and the resulting off-site dose from these emissions. This document fulfills the requirements established by the National Emissions Standards for Hazardous Air Pollutants in 40 CFR 61, Subpart H – Emissions of Radionuclides other than Radon from Department of Energy Facilities, commonly referred to as the Radionuclide NESHAP or Rad-NESHAP. Compliance with this regulation and preparation of this document is the responsibility of LANL’s RadNESHAP compliance program, which is part of the Environmental Protection Division. The information in this report is required under the Clean Air Act and is being submitted to the U.S. Environmental Protection Agency (EPA) Region 6.

Fast heavy-ion radiation damage of glycine in aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Nomura, Shinji [Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Tsuchida, Hidetsugu, E-mail: tsuchida@nucleng.kyoto-u.ac.jp [Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Quantum Science and Engineering Center, Kyoto University, Uji 611-0011 (Japan); Furuya, Ryosuke [Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Majima, Takuya; Itoh, Akio [Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Quantum Science and Engineering Center, Kyoto University, Uji 611-0011 (Japan)

2016-12-15

Fast heavy-ion radiolysis of biomolecules in aqueous solution is investigated for an atomistic understanding of radiation damage to normal cells during heavy-particle beam therapy. The smallest amino acid glycine was used as a model biomaterial. Microjets of aqueous glycine solutions under vacuum were irradiated with 4.0-MeV carbon ions corresponding to energies in the Bragg peak region. To understand the effects of the water environment on molecular damage, the yield of glycine dissociation was measured by secondary ion mass spectroscopy. The yield was significantly reduced relative to gas-phase glycine targets. This implies that the numerous water molecules surrounding a single glycine molecule act as a buffer that suppresses dissociation. This is an environmental effect similar to that observed for other biomolecular cluster targets.

Inventories of selected radionuclides in the oceans

International Nuclear Information System (INIS)

1988-10-01

In March 1984 an ad hoc Review Committee composed of senior experts in the marine radioactivity field made recommendations that ''the Monaco Laboratory should be engaged in compiling and evaluating the input of radionuclides into the marine environment''. The Committee recommended that work should commence on selected radionuclides, viz., 14 C, caesium isotopes, plutonium isotopes, 210 Po and 210 Pb followed by 226 Ra. Depending on the radionuclides involved the assistance of competent experts from outside as well as inside the IAEA was sought. The present document is a product of the work carried out within the framework of the above-mentioned task and contains reports on 14 C, 90 Sr, 137 Cs, 238 Pu, 239+240 Pu, 210 Pb, 210 Po and 226 Ra. Although the estimation of the inventory in the marine environment and related input and output fluxes, is the same for all radionuclides concerned, different approaches were followed to achieve this objective. These approaches depended on the geochemical characteristics of the radionuclides and the availability of data for different times and locations. For regions where data were lacking, extrapolation on the basis of specific assumptions has often been necessary. As the work was initiated during the pre-Chernobyl period, the radionuclides derived from the Chernobyl incident were not, in general, considered. Since the work for preparing the forthcoming report of the UNSCEAR is scheduled to be completed by 1991, it is hoped that the information contained in this volume will be beneficial. Refs, figs and tabs

New radionuclide generator systems for use in nuclear medicine

International Nuclear Information System (INIS)

Atcher, R.W.

1979-01-01

A current emphasis in nuclear medicine is to better match the physical lifetime of the radionuclides used in vivo for diagnosis and treatment to the biological lifetime of the diagnostic procedure or to minimize radiation dose to areas other than those to be treated. In many cases the biological lifetime is on the order of minutes. Since the direct production of radionuclides with half lives of minutes requires the user to be near a suitable reactor or accelerator, this study was undertaken to produce short-lived radionuclides indirectly. If a long-lived radionuclide decays into a short-lived radionuclide, quick separation of the daughter activity from the parent enables the user to have a short-lived daughter while freeing him from the constraint of proximity to a cyclotron. Systems where a short-lived daughter is separated from a long-lived parent are called radionuclide generators. Two generator systems were developed for use in nuclear medicine, one in diagnostic work and the other for therapeutic work. The yield and breakthrough characteristics were within the limits required to minimize unnecessary radiation exposure in patients. Two parent radionuclides were produced using 4 He beams available from medium energy cyclotrons. The yield was high enough to produce generators that would be useful in clinical applications

Development of a transportable system for radionuclide analysis

International Nuclear Information System (INIS)

Cunningham, W.C.; Anderson, D.L.; Lamont, W.H.; South, P.K.; Rury, M.A.; Beachley, G.M.; Ondov, J.M.

2008-01-01

Transportable radioanalytical systems were assembled and tested for quantitative determination of γ-emitting radionuclides and screening of β- emitting radionuclides. Standard operating procedures (SOPs), including instructions for assembly, disassembly, operation, sample collection and analysis, and all other procedures needed, were developed. Foods, as well as National Institute of Standards and Technology, International Atomic Energy Agency, and in-house Reference Materials were analyzed. An SOP for γ-emitting radionuclides was successfully tested at 3 locations. (author)

EBS Radionuclide Transport Abstraction

International Nuclear Information System (INIS)

J.D. Schreiber

2005-01-01

The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in ''Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration'' (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment for the license application (TSPA-LA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA-LA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport model considers

EBS Radionuclide Transport Abstraction

Energy Technology Data Exchange (ETDEWEB)

J.D. Schreiber

2005-08-25

The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in ''Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration'' (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment for the license application (TSPA-LA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA-LA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport

EBS Radionuclide Transport Abstraction

Energy Technology Data Exchange (ETDEWEB)

J. Prouty

2006-07-14

The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment (TSPA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport model considers advective transport and diffusive transport

EBS Radionuclide Transport Abstraction

International Nuclear Information System (INIS)

J. Prouty

2006-01-01

The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment (TSPA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport model considers advective transport and diffusive transport

Improving global laboratory capabilities for emergency radionuclide bioassay

International Nuclear Information System (INIS)

Li, C.; Jourdain, J.; Kramer, G. H.

2012-01-01

During a radiological or nuclear emergency, first-responders and the general public may be internally contaminated with the radionuclide(s) involved. A timely radionuclide bioassay provides important information about contamination, for subsequent dose assessment and medical management. Both technical and operational gaps are discussed in this paper. As many people may need to be assessed in a short period of time, any single laboratory may find its capabilities insufficient. Laboratories from other regions or other countries may be called upon for assistance. This paper proposes a road-map to improve global capabilities in emergency radionuclide bioassay, suggesting a phased approach for establishing a global laboratory network. Existing international collaboration platforms could provide the base on which to build such a network. (authors)

Radionuclide techniques for brain imaging

International Nuclear Information System (INIS)

Cowan, R.J.; Moody, D.M.

1984-01-01

Over the past decade, many of the prime indications for radionuclide brain scanning have become instead indications for CCT, and nuclear medicine studies of the brain have assumed more of a complementary, supportive role. However, there is great promise for improvement in central nervous system radionuclide applications with advances anticipated in both radiopharmaceuticals and instrumentation. Nuclear medicine is continuing to function as a powerful research tool and, in the relatively near future, may regain its role as a major clinical test of the central nervous system

Transfer of radionuclides to man through environmental pathways

International Nuclear Information System (INIS)

Mitchell, N.T.

1974-01-01

The most widely accepted method in current use for the evaluation of environmental impact from releases of radioactivity that may cause human radiation exposure used an environmental pathway model. The more important aspects of the model involve the use of critical pathway techniques to set controls on the releases of radioactive material to the environment and to assess the human radiation exposure arising as a consequence. The basic concepts of the environmental pathway model and its application are discussed. The model depends on achieving an understanding of radionuclide behavior in the environment, from the moment of release up to the time when contamination results in radiation exposure to the public. Exposure may be as a result of contaminated material entering the body-as air, water or a foodstuff; alternatively, it may be due to radiation whose source is external to the body. For each of these types of exposure pathway the sequence of events can be divided up into a number of compartments, between which transfer takes place. Transfer along the pathway is a dynamic process and can be described mathematically in terms of transfer functions between interacting compartments. Alternatively, for the situation of a regular discharge resulting in a steady-state condition the relationship between compartments can be expressed as a 'concentration factor'. The derivation of both of these terms is described and some aspects of their use are discussed. The paper then goes on to discuss the types of environmental pathway that are encountered as a result of release of radionuclides to the atmospheric and aquatic environments. Disposal to the ground is regarded as a special case of release to the aquatic environment. Some ot the literature on the subject is reviewed in discussingthe better known pathways showing what, to date, have been the most important mechanisms of transfer of radionuclides to man. (author)

Relating β+ radionuclides' properties by order theory

International Nuclear Information System (INIS)

Quintero, N.Y.; Guillermo Restrepo; Cohen, I.M.; Universidad Tecnologica Nacional, Buenos Aires

2013-01-01

We studied 27 β + radionuclides taking into account some of their variants encoding information of their production, such as integral yield, threshold energy and energy of projectiles used to generate them; these radionuclides are of current use in clinical diagnostic imaging by positron emission tomography (PET). The study was conducted based on physical, physico-chemical, nuclear, dosimetric and quantum properties, which characterise the β + radionuclides selected, with the aim of finding meaningful relationships among them. In order to accomplish this objective the mathematical methodology known as formal concept analysis was employed. We obtained a set of logical assertions (rules) classified as implications and associations, for the set of β + radionuclides considered. Some of them show that low mass defect is related to high and medium values of maximum β + energy, and with even parity and low mean lives; all these parameters are associated to the dose received by a patient subjected to a PET analysis. (author)

Metabolic transformation of radionuclides in marine organisms

International Nuclear Information System (INIS)

Koyanagi, Taku

1987-01-01

Physico-chemical form of radionuclides is one of the important factors governing the concentration by marine organisms, whereas biological activities affect the existing states of radionuclides especially in coastal waters. Radioiodine in the form of iodate which is predominant species in seawater is reduced to iodide ion by biological activities and concentration factor of iodide is an order of magnitude higher than those of iodate. Extremely high accumulation of transition elements, actinides, or natural radionuclides in branchial heart of octopus is explained by the fuction of adenochrome, a glandular pigment in the organ as a natural complexing agent, and similar metal-binding proteins with relatively low molecular weight have been found in various marine invertebrates. High accumulation of some elements also found in mollusk kidney is considered to be caused by the intracellular concretions composed of calcium phosphate. All these biological processes suggest the significance of further investigations on metabolic transformation of radionuclides in marine organisms. (author)

The main trends in clinical use of radionuclides in oncology

International Nuclear Information System (INIS)

Agranat, V.Z.

1979-01-01

The main trends of using radionuclide methods in clinical oncology are shown. Two main aspects of using radionuclide methods are pointed out: radionuclide investigation of the primary tumour as ''local'' manifestation of the cancer disease, radionuclide investigation of the body ''response'' to the tumour process. Each of the aspects of the problem is briefly considered on some examples. Examples of positive scintigraphy of tumours are given. It is shown that tumorotropic properties of some radionuclides make possible using visualization methods realizing the differential diagnosis of some tumours. Considered are direct and indirect signs which allow determining the presence of metastases and testifying to the tumour process spread

Observation-based estimate of the Fukushima radionuclide in the North Pacific

Science.gov (United States)

Yoshida, Sachiko; Jayne, Steven; Macdonald, Alison; Buesseler, Ken; Rypina, Irina

2014-05-01

Contaminated waters from Fukushima nuclear power plant (FNPP) were discharged directly into the North Pacific Ocean in March 2011. Coastal current system in this region and time scale of the water exchange with the open ocean is not well understood, however both observational evidence and numerical model simulation results indicate relatively rapid advection of contaminants eastward into the highly energetic mixed water region in the confluence of the Kuroshio and Oyashio. Surface drifters deployed near the FNPP in early summer 2011 show trajectories crossing the North Pacific generally following the large scale ocean circulation after one year. Previously obtained cesium (Cs) samples from multiple cruises near FNPP and off shore region between 2011 and 2013 are collected and evaluated to diagnose the propagating Cs signal crossing North Pacific Ocean. In this presentation, we use radionuclides of Fukushima origin as a tracer to understand the North Pacific circulation and mixing process after two years of release. Large numbers of the observation are repeatedly took place near shore where Cs shows still relatively higher about 10-30 Bq/m3 in 2013. Temperature-salinity (T-S) properties for the available hydrographic data indicate that the majority of the samples were obtained in the region where the water is highly influenced by the warm-salty Kuroshio origin water. Depth profiles of 35N section in March-May 2013 cruise of the U.S. Climate Variability and Predictability and Carbon (CLIVAR) repeat Hydrography sections are examined to track the radionuclide penetration into the subsurface ocean and the subduction pathways along isopycnal surfaces. Available large drifter datasets that accumulated over decades of field work can guide us in estimating the spread of these radionuclides. By applying an innovative statistical analysis to the drifter data, we investigate the spreading of radionuclides in the Pacific Ocean over 5-year time scales.

Radionuclide concentrations in white sturgeon from the Columbia River

International Nuclear Information System (INIS)

Dauble, D.D.; Price, K.R.; Poston, T.M.

1993-11-01

The objectives of this study were to (1) review and summarize historical data on radionuclide concentrations in white sturgeon from the Columbia River, (2) determine present-day radionuclide tissue burdens from different locations in the Columbia River, and (3) compare historical data with current data. We first reviewed and summarized the historical literature on radionuclide concentrations in white sturgeon from the Hanford Reach. Field studies were then conducted to evaluate the relationship among sample locations, age/length of white sturgeon, and present radionuclide tissue burdens. Results and comparisons are discussed in the remainder of this report

Radionuclide Therapies in Molecular Imaging and Precision Medicine.

Science.gov (United States)

Kendi, A Tuba; Moncayo, Valeria M; Nye, Jonathon A; Galt, James R; Halkar, Raghuveer; Schuster, David M

2017-01-01

This article reviews recent advances and applications of radionuclide therapy. Individualized precision medicine, new treatments, and the evolving role of radionuclide therapy are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

CRRIS, Health Risk Assessment from Atmospheric Releases of Radionuclides

International Nuclear Information System (INIS)

1999-01-01

1 - Description of program or function: CRRIS consists of eight fully integrated computer codes which calculate environmental transport of atmospheric releases of radionuclides and resulting doses and health risks to individuals or populations. Each code may be used alone for various assessment applications. Because of its modular structure, CRRIS allows assessments to be tailored to the user's needs. Radionuclides are handled by CRRIS either in terms of the released radionuclides or the exposure radionuclides which consist of both the released nuclides and decay products that build up during environmental transport. Atmospheric dispersion calculations are performed by the ANEMOS computer code for distances less than 100 km and the RETADD-II computer code regional-scale distances. Both codes estimate annual-average air concentrations and ground deposition rates by location. SUMIT will translate and scale multiple ANEMOS runs onto a master grid. TERRA reads radionuclide air concentrations and deposition rates to estimate concentrations of radionuclides in food and surface soil. Radiologic decay and ingrowth, soil leaching, and transport through the food chain are included in the calculations. MLSOIL computes an effective radionuclide ground-surface concentration to be used in computing external health effects. The five-layer model of radionuclide transport through soil in MLSOIL provides an alternative to the single-layer model used in TERRA. DFSOIL computes dose factors used in MLSOIL to compute doses from the five soil layers and from the ground surface. ANDROS reads environmental concentrations of radionuclides computed by the other CRRIS codes and produces tables of doses and risks to individuals or populations from atmospheric releases of radionuclides. 2 - Method of solution: SUMIT performs geometric interpolation. TERRA and MLSOIL are terrestrial transport compartment models. DFSOIL computes soil-layer-specific dose factors based on the point-kernel method

The behaviour of radionuclides in soil

International Nuclear Information System (INIS)

Bunzl, K.

1987-01-01

Radionuclides in soil are of natural as well as of artificial origin. Their migration in the soil and their availability for ecological processes depend considerably on the extent at which they are sorbed. The methods for the determination of the vertical rate of migration are described. For most radionuclides this transport is very slow (a few cm per year). Cs-137 is of especial interest. It is sorbed strongly by most soils and, as a consequence, its root uptake is small. However, as a result of the sorption, this radionuclide is eluted from the root zone only very slowly and its thus available for the root uptake for many years. The Cs-137 concentrations in plants to be expected in the coming years as a result of the fallout from Chernobyl are small. (orig.) [de

Transport of radionuclides in the biosphere

International Nuclear Information System (INIS)