WorldWideScience

Sample records for chemical co-precipitations decontamination

  1. Chemical decontamination method

    International Nuclear Information System (INIS)

    Nishiwaki, Hitoshi.

    1996-01-01

    Metal wastes contaminated by radioactive materials are contained in a rotational decontamination vessel, and the metal wastes are rotated therein while being in contact with a slight amount of a decontamination liquid comprising a mineral acid. As the mineral acid, a mixed acid of nitric acid, hydrochloric acid and fluoric acid is preferably used. Alternatively, chemical decontamination can also be conducted by charging an acid resistant stirring medium in the rotational decontamination vessel. The surface of the metal wastes is uniformly covered by the slight amount of decontamination liquid to dissolve the surface layer. In addition, heat of dissolution generated in this case is accumulated in the inside of the rotational decontamination vessel, the temperature is elevated with no particular heating, thereby enabling to obtain an excellent decontamination effect substantially at the same level as in the case of heating the liquid to 70degC in a conventional immersion decontamination method. Further, although contact areas between the metal wastes and the immersion vessel are difficult to be decontaminated in the immersion decontamination method, all of areas can be dissolved uniformly in the present invention. (T.M.)

  2. Removal of some Fission Products from Low Level Liquid Radioactive Waste by Chemical Precipitation liquid/Co-precipitation / Phosphate Coagulant

    International Nuclear Information System (INIS)

    Borai, E.H.; Attallah, M.F.; Hilal, M.A.; Abo-Aly, M.M.; Shehata, F.A.

    2008-01-01

    In Egypt radioactive waste has been generated from various uses of radioactive materials. Presence of cesium demonstrated a major problem from the removal point of view even by conventional and advanced technologies. Selective chemical precipitation has been oriented for removal of some fission products including 137 Cs from low level liquid radioactive waste (LLLRW). The aim of the present study was focused to investigate the effectiveness of various phosphate compounds that improved the precipitation process and hence the decontamination factor. The results showed that, maximum removal of 137 Cs reaching 46.4 % using di-sodium hydrogen phosphate as a selective coagulant. It was found that significant enhancement of co-precipitation of 137 Cs (62.5 %) was obtained due to presence of Nd 3+ in the LLLRW

  3. Chemical decontamination: an overview

    International Nuclear Information System (INIS)

    Shaw, R.A.; Wood, C.J.

    1985-01-01

    The source of radioactive contamination in various types of power reactors is discussed. The methods of chemical decontamination vary with the manner in which the radioactive contaminants are deposited on the surface. Two types of dilute decontamination systems are available. One system uses organic acids and chelating agents, which are mildly reducing in nature. In this process, the oxide contaminants are removed by simple acidic dissolution and reductive dissolution. The second type of decontamination process is based on low oxidation state metal ions, which are more strongly reducing and do not require a corrosion inhibitor. All processes commercially available for decontamination of power reactors are not detailed here, but a few key issues to be considered in the selection of a process are highlighted. 2 figures, 2 tables

  4. PEG capped CaS nanoparticles synthesized by wet chemical co-precipitation method

    Science.gov (United States)

    Rekha, S.; Anila, E. I.

    2018-04-01

    Calcium sulfide (CaS) nanoparticles capped with polyethyleneglycol (PEG) were synthesized using wet chemical co-precipitation method. The structural and optical properties of the prepared sample were studied by X-ray diffractogram (XRD), transmission electron microscopy (TEM), diffuse reflectance spectrum (DRS) and photoluminescence (PL) spectrum. The structure of CaS nanoparticles is cubic as demonstrated by the X-ray powder diffraction (XRD) and selected area electron diffraction (SAED) analysis. TEMimage revealed the spherical morphology of the particles with diameter in the range 15-20 nm. The optical band gap of the prepared sample was determined from the DRS and its value was found to be 4.1 eV. The PL studies showed that the relative intensity of the PEG capped CaS nanoparticles was higher than that of uncapped CaS nanoparticles. The presence of various functional groups in the capped samples were examined by Fourier Transform Infrared (FTIR) spectroscopy.

  5. Chemical decontamination of metals

    International Nuclear Information System (INIS)

    Partridge, J.A.; Lerch, R.E.

    1979-10-01

    A metal decontamination process based upon removal of contamination by treatment with a cerium (IV)-nitric acid solution (or other redox agent in nitric acid) is feasible and highly promising. The technique is effective in dissolving the surface layer of stainless steel. Dissolution rates of approximately 1.5 mils/h were demonstrated with cerium (IV)-nitric acid solutions. Removal of plutonium contamination from stainless steel was demonstrated in laboratory tests, in which activity levels were reduced from greater than 5 x 10 5 counts per minute to nondetectable levels in approximately one hour at 90 0 C. Removal of paint from stainless steel surfaces was also demonstrated. Advantages of this process over other chemical solutions include: (1) The solutions are not high salt systems; therefore, there is potentially less waste generated. (2) Cerium(IV) in nitric acid is a good dissolution agent for plutonium oxide. (3) Regeneration of Ce(IV) during the decontamination is accomplished by electrolysis. (4) The process should be effective for irregularly shaped equipment. (5) It could be effective as a spray or a flow-through system. 13 figures

  6. Preparation of palladium nanoparticles on alumina surface by chemical co-precipitation method and catalytic applications

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Avvaru Praveen; Kumar, B. Prem; Kumar, A.B.V. Kiran; Huy, Bui The [Department of Chemistry, Changwon National University, Changwon 641-773 (Korea, Republic of); Lee, Yong-Ill, E-mail: yilee@changwon.ac.kr [Department of Chemistry, Changwon National University, Changwon 641-773 (Korea, Republic of)

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer Facile synthesis of palladium nanoparticles on alumina surface. Black-Right-Pointing-Pointer The surface morphology and properties of the nanocrystalline powders were characterized. Black-Right-Pointing-Pointer The catalytic activities of palladium nanoparticles were investigated. - Abstract: The present work reports a chemical co-precipitation process to synthesize palladium (Pd) nanoparticles using alumina as a supporting material. The optimized temperature for the formation of nanocrystalline palladium was found to be 600 Degree-Sign C. The X-ray diffraction (XRD) and Raman spectroscopy were used to study the chemical nature of the Pd in alumina matrix. The surface morphology and properties of the nanocrystalline powders were examined using thermogravimetric analysis (TG-DTA), XRD, Raman spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The calcinations in different atmospheres including in the inert medium forms the pure nano Pd{sup 0} while in the atmospheric air indicates the existence pure Pd{sup 0} along with PdO nanoparticles. The catalytic activities of the as-synthesized nanocrystalline Pd nanoparticles in the alumina matrix were investigated in Suzuki coupling, Hiyama cross-coupling, alkene and alkyne hydrogenation, and aerobic oxidation reactions.

  7. Synthesis and characterization of magnetite nanoparticles via the chemical co-precipitation method

    International Nuclear Information System (INIS)

    Petcharoen, K.; Sirivat, A.

    2012-01-01

    Highlights: ► Size-controlled magnetite nanoparticles were prepared via the chemical co-precipitation method in the range of 10–40 nm. ► The electrical conductivity of the smallest particle size is 1.3 × 10 −3 S/cm which belongs to the semiconductor material group. ► The surface modification of magnetite nanoparticles can provide the suspension stability over 1 week. - Abstract: Magnetite nanoparticles were synthesized via the chemical co-precipitation method using ammonium hydroxide as the precipitating agent. The size of the magnetite nanoparticles was carefully controlled by varying the reaction temperature and through the surface modification. Herein, the hexanoic acid and oleic acid were introduced as the coating agents during the initial crystallization phase of the magnetite. Their structure and morphology were characterized by the Fourier transform infrared spectroscopy (FTIR), the X-ray diffraction (XRD) and the field-emission scanning electron microscopy (FE-SEM). Moreover, the electrical and magnetic properties were studied by using a conductivity meter and a vibrating sample magnetometer (VSM), respectively. Both of the bare magnetite and the coated magnetite were of the cubic spinel structure and the spherical-shaped morphology. The reaction temperature and the surface modification critically affected the particle size, the electrical conductivity, and the magnetic properties of these particles. The particle size of the magnetite was increased through the surface modification and reaction temperature. In this study, the particle size of the magnetite nanoparticles was successfully controlled to be in the range of 10–40 nm, suitable for various biomedical applications. The electrical conductivity of the smallest particle size was 1.3 × 10 −3 S/cm, within the semi-conductive materials range, which was higher than that of the largest particle by about 5 times. All of the magnetite nanoparticles showed the superparamagnetic behavior with

  8. Dilute chemical decontamination program review

    International Nuclear Information System (INIS)

    Anstine, L.D.; Blomgren, J.C.; Pettit, P.J.

    1980-01-01

    The objective of the Dilute Chemical Decontamination Program is to develop and evaluate a process which utilizes reagents in dilute concentrations for the decontamination of BWR primary systems and for the maintenance of dose rates on the out-of-core surfaces at acceptable levels. A discussion is presented of the process concept, solvent development, advantages and disadvantages of reagent systems, and VNC loop tests. Based on the work completed to date it is concluded that (1) rapid decontamination of BWRs using dilute reagents is feasible; (2) reasonable reagent conditions for rapid chemical decontamination are: 0.01M oxalic acid + 0.005M citric acid, pH3.0, 90/degree/C, 0.5 to 1.0 ppm dissolved oxygen; (3) control of dissolved oxygen concentration is important, since high levels suppress the rate of decontamination and low levels allow precipitation of ferrous oxalate. 4 refs

  9. Chemical Gel for Surface Decontamination

    International Nuclear Information System (INIS)

    Jung, Chong Hun; Moon, J. K.; Won, H. J.; Lee, K. W.; Kim, C. K.

    2010-01-01

    Many chemical decontamination processes operate by immersing components in aggressive chemical solutions. In these applications chemical decontamination technique produce large amounts of radioactive liquid waste. Therefore it is necessary to develop processes using chemical gels instead of chemical solutions, to avoid the well-known disadvantages of chemical decontamination techniques while retaining their high efficiency. Chemical gels decontamination process consists of applying the gel by spraying it onto the surface of large area components (floors, walls, etc) to be decontaminated. The gel adheres to any vertical or complex surface due to their thixotropic properties and operates by dissolving the radioactive deposit, along with a thin layer of the gel support, so that the radioactivity trapped at the surface can be removed. Important aspects of the gels are that small quantities can be used and they show thixitropic properties : liquid during spraying, and solid when stationary, allowing for strong adherence to surfaces. This work investigates the decontamination behaviors of organic-based chemical gel for SS 304 metallic surfaces contaminated with radioactive materials

  10. Chemical decontamination of stainless steel

    International Nuclear Information System (INIS)

    Onuma, Tsutomu; Akimoto, Hidetoshi

    1991-01-01

    The present invention concerns a method for chemical decontamination of radioactive metal waste materials contaminated with radioactive materials on the surface, generated in radioactive materials-handling facilities. The invention is comprised of a method of chemical decontamination of stainless steel, characterized by comprising a first process of immersing a stainless steel-based metal waste material contaminated by radioactive materials on the surface in a sulfuric acid solution and second process of immersing in an aqueous solution of sulfuric acid and oxidizing metal salt, in which a portion of the surface of the stainless steel to be decontaminated is polished mechanically to expose a portion of the base material before the above first and second processes. 1 figs., 2 tabs

  11. Chemical decontamination method in nuclear facility system

    International Nuclear Information System (INIS)

    Takahashi, Ryota; Sakai, Hitoshi; Oka, Shigehiro.

    1996-01-01

    Pumps and valves in a closed recycling loop system incorporating materials to be chemically decontaminated are decomposed, a guide plate having the decomposed parts as an exit/inlet of a decontaminating liquid is formed, and a decontaminating liquid recycling loop comprising a recycling pump and a heater is connected to the guide plate. Decontaminating liquid from a decontaminating liquid storage tank is supplied to the decontaminating liquid recycling loop. With such constitutions, the decontaminating liquid is filled in the recycling closed loop system incorporating materials to be decontaminated, and the materials to be decontaminated are chemically decontaminated. The decontaminating liquid after the decontamination is discharged and flows, if necessary, in a recycling system channel for repeating supply and discharge. After the decontamination, the guide plate is removed and returned to the original recycling loop. When pipelines of a reactor recycling system are decontaminated, the amount of decontaminations can be decreased, and reforming construction for assembling the recycling loop again, which requires cutting for pipelines in the system is no more necessary. Accordingly, the amount of wastes can be decreased, and therefore, the decontamination operation is facilitated and radiation dose can be reduced. (T.M.)

  12. Chemical decontaminating method for stainless steel

    International Nuclear Information System (INIS)

    Onuma, Tsutomu; Akimoto, Hidetoshi.

    1990-01-01

    Radioactive metal wastes comprising passivated stainless steels are chemically decontaminated to such a radioactivity level as that of usual wastes. The present invention for chemically decontaminating stainless steels comprises a first step of immersing decontaminates into a sulfuric acid solution and a second step of immersing them into an aqueous solution prepared by adding oxidative metal salts to sulfuric acid, in which a portion of the surface of stainless steels as decontaminates are chemically ground to partially expose substrate materials and then the above-mentioned decontamination steps are applied. More than 90% of radioactive materials are removed in this method by the dissolution of the exposed substrate materials and peeling of cruds secured to the surface of the materials upon dissolution. This method is applicable to decontamination of articles having complicate shapes, can reduce the amount of secondary wastes after decontamination and also remarkably shorten the time required for decontamination. (T.M.)

  13. Chemical decontamination and melt densification

    International Nuclear Information System (INIS)

    Dillon, R.L.; Griggs, B.; Kemper, R.S.; Nelson, R.G.

    1976-01-01

    Preliminary studies on the chemical decontamination and densification of Zircaloy, stainless steel, and Inconel undissolved residues remaining after dissolution of the UO 2 --PuO 2 spent fuel material from sheared fuel bundles are reported. The studies were made on cold or very small samples to demonstrate the feasibility of the processes developed before proceeding to hot cell demonstrations with kg level of the sources. A promising aqueous decontamination method for Zr alloy cladding was developed in which oxidized surfaces are conditioned with HF prior to leaching with ammonium oxalate, ammonium citrate, ammonium fluoride, and hydrogen peroxide. Feasibility of molten salt decontamination of oxidized Zircaloy was demonstrated. A low melting alloy of Zircaloy, stainless steel, and Inconel was obtained in induction heated graphite crucibles. Segregated Zircaloy cladding sections were directly melted by the inductoslag process to yield a metal ingot suitable for storage. Both Zircaloy and Zircaloy--stainless steel--Inconel alloys proved to be highly satisfactory getters and sinks for recovered tritium

  14. Chemical cleaning, decontamination and corrosion

    International Nuclear Information System (INIS)

    Gadiyar, H.S.; Das Chintamani; Gaonkar, K.B.

    1991-01-01

    Chemical cleaning of process equipments and pipings in chemical/petrochemical industries is necessitated for improving operation, for preventing premature failures and for avoiding contamination. In developing a chemical formulation for cleaning equipments, the important aspects to be considered include (i) effective removal of corrosion products and scales, (ii) minimum corrosion of the base metal, (iii) easy to handle chemicals and (iv) economic viability. As on date, a wide variety of chemical formulations are available, many of them are either proprietory or patented. For evolving an effective formulation, knowledge of the oxides of various metals and alloys on the one hand and acid concentration, complexing agents and inhibitors to be incorporated on the other, is quite essential. Organic acids like citric acid, acetic acid and formic acid are more popular ones, often used with EDTA for effective removal of corrosion products from ferrous components. The report enumerates some of the concepts in developing effective formulations for chemical cleaning of carbon steel components and further, makes an attempt to suggest simple formulations to be developed for chemical decontamination. (author). 6 refs., 3 fi gs., 4 tabs

  15. Cost effectiveness of dilute chemical decontamination

    International Nuclear Information System (INIS)

    LeSurf, J.E.; Weyman, G.D.

    The basic principles of dilute chemical decontamination are described, as well as the method of application. Methods of computing savings in radiation dose and costs are presented, with results from actual experience and illustrative examples. It is concluded that dilute chemical decontamination is beneficial in many cases. It reduces radiation exposure of workers, saves money, and simplifies maintenance work

  16. Testing and evaluation of eight decontamination chemicals

    International Nuclear Information System (INIS)

    Demmer, R.

    1994-09-01

    This report covers experimental work comparing eight different decontamination chemicals. Seven of these chemicals have some novelty, or are not currently in use at the ICPP. The eighth is a common ICPP decontamination reagent used as a baseline for effective comparison. Decontamination factors, waste generation values, and corrosion rates are tabulated for these chemicals. Recommendations are given for effective methods of non-sodium or low-sodium decontamination chemicals. The two most effective chemical for decontamination found in these test were a dilute hydrofluoric and nitric acid (HF/HNO 3 ) mixture and a fluoroboric acid solution. The fluoroboric acid solution (1 molar) was by far the most effective decontamination reagent, but suffered the problem of generating significant final calcine volume. The HF/HNO 3 solution performed a very good decontamination of the SIMCON coupons while generating only small amounts of calcine volume. Concentration variables were also tested, and optimized for these two solutions. Several oxidation/reduction decon chemical systems were also tested. These systems were similar to the TURCO 4502 and TURCO 4521 solutions used for general decontamination at the ICPP. A low sodium alternative, nitric acid/potassium permanganate, to the ''high sodium'' TURCO 4502 was tested extensively, optimized and recommended for general ICPP use. A reductive chemical solution, oxalic acid/nitric acid was also shown to have significant advantages

  17. Recent developments in chemical decontamination technology

    Energy Technology Data Exchange (ETDEWEB)

    Wood, C.J. [Electric Power Research Institute, Palo Alto, CA (United States)

    1995-03-01

    Chemical decontamination of parts of reactor coolant systems is a mature technology, used routinely in many BWR plants, but less frequently in PWRs. This paper reviews recent developments in the technology - corrosion minimization, waste processing and full system decontamination, including the fuel. Earlier work was described in an extensive review published in 1990.

  18. Photoluminescence and magnetic properties of Fe-doped ZnS nano-particles synthesized by chemical co-precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Nie Eryong; Liu Donglai; Zhang Yunsen; Bai Xue; Yi Liang; Jin Yong; Jiao Zhifeng [School of Materials Science and Engineering, Sichuan University, Chengdu 610064, Sichuan (China); Sun Xiaosong, E-mail: sunxs@scu.edu.cn [School of Materials Science and Engineering, Sichuan University, Chengdu 610064, Sichuan (China)

    2011-08-15

    This paper is focusing on the synthesis of Zn{sub 1-x}Fe{sub x}S nano-particles with x = 0, 0.1 and 0.2 by chemical co-precipitation method, the prepared of which are characterized by XRD, EDS, TEM, PL, magnetization versus field behavior and M-T curve. In the XRD patterns, Zn{sub 1-x}Fe{sub x}S nano-particles are shown of cubic zinc blende structure, and the broadening diffraction peaks consistent with the small-size characteristic of nano-materials. The diameter of nano-particles is between 3.3 and 5.5 nm according to the HR-TEM images. The EDS data confirm the existence of Fe ions in Fe-doped ZnS nanoparticles. There we found that Fe-doping did not import new energy bands or defect states, but reduced the intensity of PL peaks. The magnetization versus field behaviors were illustrated by the M-H curves at both 5 K and 300 K, respectively, where no remanence or coercive force was observed. This phenomenon indicates that the Zn{sub 1-x}Fe{sub x}S (x = 0.1) nano-particles are superparamagnetic. The zero-field-cooled (ZFC) and field-cooled (FC) magnetization curves further reveal that the blocking temperature (T{sub B}) of the superparamagnetic behavior might be below 5 K.

  19. [Decontamination of chemical and biological warfare agents].

    Science.gov (United States)

    Seto, Yasuo

    2009-01-01

    Chemical and biological warfare agents (CBWA's) are diverse in nature; volatile acute low-molecular-weight toxic compounds, chemical warfare agents (CWA's, gaseous choking and blood agents, volatile nerve gases and blister agents, nonvolatile vomit agents and lacrymators), biological toxins (nonvolatile low-molecular-weight toxins, proteinous toxins) and microbes (bacteria, viruses, rickettsiae). In the consequence management against chemical and biological terrorism, speedy decontamination of victims, facilities and equipment is required for the minimization of the damage. In the present situation, washing victims and contaminated materials with large volumes of water is the basic way, and additionally hypochlorite salt solution is used for decomposition of CWA's. However, it still remains unsolved how to dispose large volumes of waste water, and the decontamination reagents have serious limitation of high toxicity, despoiling nature against the environments, long finishing time and non-durability in effective decontamination. Namely, the existing decontamination system is not effective, nonspecifically affecting the surrounding non-target materials. Therefore, it is the urgent matter to build up the usable decontamination system surpassing the present technologies. The symposiast presents the on-going joint project of research and development of the novel decontamination system against CBWA's, in the purpose of realizing nontoxic, fast, specific, effective and economical terrorism on-site decontamination. The projects consists of (1) establishment of the decontamination evaluation methods and verification of the existing technologies and adaptation of bacterial organophosphorus hydrolase, (2) development of adsorptive elimination technologies using molecular recognition tools, and (4) development of deactivation technologies using photocatalysis.

  20. Chemically reducing decontamination method for radioactive metal

    International Nuclear Information System (INIS)

    Tanaka, Akio; Onuma, Tsutomu; Sato, Hitoshi.

    1994-01-01

    The present invention concerns a decontamination method of electrolytically reducing radioactive metal wastes, then chemically dissolving the surface thereof with a strong acid decontaminating solution. This method utilizes dissolving characteristics of stainless steels in the strong acid solution. That is, in the electrolytic reduction operation, a portion of the metal wastes is brought into contact with a strong acid decontaminating solution, and voltage and current are applied to the portion and keep it for a long period of time so as to make the potential of the immersed portion of the metal wastes to an active soluble region. Then, the electrolytic reduction operation is stopped, and the metal wastes are entirely immersed in the decontaminating solution to decontaminate by chemical dissolution. As the decontaminating solution, strong acid such as sulfuric acid, nitric acid is used. Since DC current power source capacity required for causing reaction in the active soluble region can be decreased, the decontamination facility can be minimized and simplified, and necessary electric power can be saved even upon decontamination of radioactive metal wastes made of stainless steels and having a great area. Further, chemical dissolution can be conducted without adding an expensive oxidizing agent. (N.H.)

  1. Testing and comparison of seventeen decontamination chemicals

    International Nuclear Information System (INIS)

    Demmer, R.L.

    1996-09-01

    This report details the testing and evaluation of seventeen decontamination chemicals. Tests were conducted with SIMCON (simulated contamination) coupons under controlled conditions to compare cleaning effectiveness, overall corrosion potential for plant equipment, interim waste generation and final waste generation

  2. Enzymatic Decontamination of Chemical Warfare Agents

    National Research Council Canada - National Science Library

    Raushel, Frank

    2000-01-01

    The primary objective of this research program is the development of a versatile enzyme-based system that is fully optimized for the decontamination, destruction, and detection of know chemical warfare agents...

  3. Mechanical and chemical decontamination of surfaces

    International Nuclear Information System (INIS)

    Kienhoefer, M.

    1982-01-01

    Decontamination does not mean more than a special technique of cleaning surfaces by methods well known in the industry. The main difference consists in the facts that more than just the visible dirt is to be removed and that radioactive contamination cannot be seen. Especially, intensive mechanical and chemical carry-off methods are applied to attack the surfaces. In order to minimize damages caused to the surfaces, the decontamination method is to adapt to the material and the required degree of decontamination. The various methods, their advantages and disadvantages are described, and the best known chemical solutions are shown. (orig./RW)

  4. Chemical decontamination process and device therefor

    International Nuclear Information System (INIS)

    Takahashi, Ryota; Sakai, Hitoshi

    1998-01-01

    The present invention provides a process and a device for chemical decontamination, which can suppress corrosion of low corrosion resistant materials, keep decontamination properties substantially as same as before and further, reduce the volume of secondary wastes. In a step of reductively melting oxide membranes on an objective material to be decontaminated, a mixture of oxalic acid and a salt thereof is used as a reducing agent, and the reductive melting is conducted while suppressing hydrogen ion concentration of an aqueous liquid system. In order to enhance the reducibility of the oxalic acid ions, it is desirable to add a cyclic hetero compound thereto. The device of the present invention comprises, a decontamination loop including a member to be decontaminated, a heater and a pH meter, a medical injection pump for injecting a reducing agent to the decontamination loop, a metal ion recovering loop including an ion exchange resin tower, a reducing agent decomposing loop including an electrolytic vessel and/or a UV ray irradiation cell, a circulation pump for circulating the decontamination liquid to each of the loops and a plurality of opening/closing valves for switching the loop in which the decontamination liquid is circulated. (T.M.)

  5. Chemical Decontamination at Browns Ferry Unit 1

    International Nuclear Information System (INIS)

    Hartwig, Ed; Reid, Richard

    2003-01-01

    In May, 2002, the Tennessee Valley Authority's (TVA) Board of Directors approved the recovery and restart of Unit 1 at Browns Ferry Nuclear Station. As an initial step in the site characterization and restart feasibility review, a majority of the primary reactor circuit was chemically decontaminated. Close cooperation between TVA and vendor personnel resulted in project completion ahead of schedule with outstanding results. The final average decontamination factors were excellent, and the final dose rates were very low, with contact readings on most points between one and three mRem/hr. In addition to allowing TVA to do a complete and thorough job of determining the feasibility of the Unit 1 restart, the decontamination effort will greatly reduce personnel exposure during plant recovery, both whole body exposure to gamma radiation and airborne exposure during pipe replacement efforts. The implementation of lessons learned from previous decontamination work performed at Browns Ferry, as well as decontamination efforts at other plants aided greatly in the success. Specific items of note are: (1) The initial leak check of the temporary decontamination system should include ancillary systems such as the spent resin system, as well as the main circulation loop. This could save time and dose exposure if leaks are discovered before the use of such systems is required. (2) Due to the quick turnaround time from the award of contract, a vendor representative was onsite early in the project to help with engineering efforts and procedures. This aided greatly in completing preparations for the decontamination. (3) The work was performed under a single maintenance activity. This resulted in great craft and plant support. (4) The constant coverage by the site's decontamination flush directors provided timely plant support and interface. (5) The FPC system isolation and back flushing to prevent residual chemicals from being left in the FPC system should have been addressed in more

  6. Chemical decontamination of reactor components

    International Nuclear Information System (INIS)

    Riess, R.; Berthold, H.O.

    1977-08-01

    A solution for the decontamination of reactor components of the primary system was developed. This solution is a modification of the APAC- (Alkaline Permanganate Ammonium Citrate) system described in the literature. The most important advantage of the present solution over the APAC-method is that it does not induce any selective corrosion attack on materials like stainless steel (austenitic), Inconel 600 and Incoloy 800. (orig.) [de

  7. Two-step chemical decontamination technology

    International Nuclear Information System (INIS)

    Rankin, W.N.

    1992-01-01

    An improved two-step chemical decontamination technique was recently developed at INEL. This memorandum documents the addition of this technology to the SRTC arsenal of decontamination technology. A two-step process using NAOH, KMnO 4 followed by HNO 3 was used for cleaning doorstops (small casks) in the SRTC High Level Caves in 1967. Subsequently, more aggressive chemical techniques have been found to be much more effective for our applications. No further work on two-step technology is planned

  8. Chemical decontamination solutions: Effects on PWR equipment

    International Nuclear Information System (INIS)

    Pezze, C.M.; Colvin, E.R.; Aspden, R.G.

    1992-01-01

    A critical objective for the nuclear industry is the reduction of personnel exposure to radiation. Reductions have been achieved through industry's radiation management programs including training and radiation awareness concepts. Increased plant maintenance and higher radiation fields at many sites continue to raise concerns. To alleviate the radiation exposure problem, the sources of radiation which contribute to personnel exposure must be removed from the plant. A feasible was of significantly reducing these sources from a Pressurized Water Reactor (PWR) is to chemically decontaminate the entire reactor coolant system (RCS). A program was conducted to determine the technical acceptability of using certain dilute chemical solvent processes for full RCS chemical decontamination. The two processes evaluated were CAN-DEREM and LOMI. The purpose of the program was to define and complete a systematic evaluation of the major issues that need to be addressed for the successful decontamination of the entire RCS and affected portions of the auxiliary systems of a four-loop PWR system. A test program was designed to evaluate the corrosion effects of the two decontamination processes under expected plant conditions. Materials and sample configurations dictated by generic PWR components were evaluated. The testing also included many standard corrosion coupons. The test data were then used to assess the impact of chemical decontamination on the physical condition and operability of the components, equipment and mechanical systems that make up the RCS. An overview of the test program, sample configurations, data and engineering evaluations is presented. The data demonstrate that through detailed engineering evaluations of corrosion data and equipment function, the impact of full RCS chemical decontamination on plant equipment is established

  9. Reactivity of Dual-Use Decontaminants with Chemical Warfare Agents

    Science.gov (United States)

    2016-07-01

    REACTIVITY OF DUAL-USE DECONTAMINANTS WITH CHEMICAL WARFARE AGENTS ECBC-TR-1384... Decontaminants with Chemical Warfare Agents 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Willis, Matthew P...extraction) of chemical warfare agents from materials. 15. SUBJECT TERMS GD HD Decontamination Hazard mitigation VX Chemical warfare agent Liquid-phase

  10. Method of chemical decontamination of stainless steel

    International Nuclear Information System (INIS)

    Onuma, Tsutomu; Akimoto, Hidetoshi.

    1989-01-01

    The present invention concerns a decontamination method of chemically decontaminating radioactive metal wastes of passivated stainless steels to a radioactivity level identical with usual wastes, in which the amount of oxidizable metal salts used is decreased. Metal wastes of stainless steels contaminated at their surface with radioactive materials are immersed in a sulfuric acid solution. In this case, a voltage is applied for a certain period of time so that the potential of the stainless steels comes to an active region. Then, oxidizable metal salt (tetravalent cerium) is added into the sulfuric acid solution. According to this method, since most of radioactive materials are removed in the immersing step to the sulfuric acid solution, the amount of the tetravalent cerium used is as less as 1/700 and the decontamination time is as short as 1/4 as compared with those in the conventional method. (K.M.)

  11. Chemical decontamination method for radioactive metal waste

    International Nuclear Information System (INIS)

    Onuma, Tsutomu; Akimoto, Hidetoshi

    1991-01-01

    The invention relates to a decontamination method for radioactive metal waste products derived from equipment that handles radioactive materials whose surfaces have been contaminated; in particular it concerns a decontamination method that reduces the amount of radioactive waste by decontaminating radioactive waste substances to a level of radioactivity in line with normal waste products. In order to apply chemical decontamination to metal waste products whose surfaces are divided into carbon steel waste and stainless steel waste; the carbon steel waste is treated using only a primary process in which the waste is immersed in a sulfuric acid solution, while the stainless steel waste must be treated with both the primary process and then electrolytically reduces it for a specific length of time and a secondary process that uses a solution of sulfuric acid mixed with oxidizing metal salts. The method used to categorize metal waste into carbon steel waste and stainless steel waste involves determining the presence, or absence, of magnetism. Voltage is applied for a fixed duration; once that has stopped, electrolytic reduction repeats the operative cycle of applying, then stopping voltage until the potential of the radioactive metal waste is retained in the active region. 1 fig. 2 tabs

  12. Chemical decontamination method for radioactive metal waste

    International Nuclear Information System (INIS)

    Onuma, Tsutomu; Tanaka, Akio; Shibuya, Sadao.

    1991-01-01

    When contaminants mainly composed of copper remained on the surface of stainless steel wastes sent from an electrolytic reduction as a first step are chemically decontaminated, metal wastes are discriminated to carbon steel wastes and stainless steel wastes. Then, the carbon steel wastes are applied only with the first step of immersing in a sulfuric acid solution, and stainless steel wastes are applied with a first step of immersing into a sulfuric acid solution for electrolytic reduction for a predetermined period of time and a second step of immersing into a liquid in which an oxidative metal salt is added to sulfuric acid. The decontamination liquid which is used for immersing the stainless steel wastes in the second step and the oxidation force of which is lowered is used as the sulfuric acid solution in the first step for the carbon steel wastes. In view of the above, the decontamination liquid of the second step can be utilized most effectively, enabling to greatly decrease the secondary wastes and to improve decontamination efficiency. (T.M.)

  13. Chemical decontamination of radioactive waste

    International Nuclear Information System (INIS)

    Mohamed, H.I.

    2006-01-01

    Radioactive wastes are generated in a number of different kinds of facilities and arise in a wide range of concentrations of radioactive materials and in a variety of physical and chemical forms. There is also a variety of alternatives for treatment and conditioning of the wastes prior disposal. The importance of treatment of radioactive waste for protection of human and environment has long been recognized and considerable experience has gained in this field. Generally, the methods used for treatment of radioactive wastes can be classified into three type's biological, physical and chemical treatment this physical treatment it gives good result than biological treatment. Chemical treatment is fewer hazards and gives good result compared with biological and physical treatments. Chemical treatment is fewer hazards and gives good result compared with biological and physical treatments. In chemical treatment there are different procedures, solvent extraction, ion exchange, electro dialysis but solvent extraction is best one because high purity can be optioned on the other hand the disadvantage that it is expensive. Beside the solvent extraction technique one can be used is ion exchange which gives reasonable result, but requires pretreatment that to avoid in closing of column by colloidal and large species. Electro dialysis technique gives quite result but less than solvent extraction and ion exchange technique the advantage is a cheep.(Author)

  14. Evaluation of commercially available decontamination chemicals

    International Nuclear Information System (INIS)

    Shurte, E.A.; Rankin, W.N.

    1988-01-01

    The effectiveness of commercially available decontamination solutions was compared with the effectiveness of 10% oxalic acid in controlled laboratory tests. Type 304L stainless steel and Inconel 625 specimens were used. Contamination was sludge from Savannah River Plant (SRP) high level waste tanks. Measured amounts of contamination were placed on each specimen. They were then heated to bond the contamination to the surface and cleaned according to the manufacturer's directions. The effectiveness of the product was determined by monitoring specimens before and after cleaning. Four of the 16 solutions evaluated removed all the contamination from Type 304L stainless steel. Inconel 625 was more difficult to decontaminate. Further tests are planned with the chemicals that were most effective in this test. 4 refs., 6 tabs

  15. Evaluation of commercially available decontamination chemicals

    International Nuclear Information System (INIS)

    Shurte, E.A.

    1988-01-01

    The effectiveness of commercially available decontamination solutions was compared with the effectiveness of 10% oxalic acid in controlled lab. tests. Type 304L stainless steel and Inconel 625 specimens were used. Contamination was sludge from Savannah River Plant (SRP) high level waste tanks. Measured amounts of contamination were placed on each specimen. They were then heated to bond the contamination to the surface and cleaned according to the manufacturer's directions. The effectiveness of the produce was determined by monitoring specimens before and after cleaning. Four of the 16 solutions evaluated removed all the contamination from Type 304L stainless steel. Inconel 625 was more difficult to decontaminate. Further tests are planned with the chemicals that were most effective in this test

  16. Reactive skin decontamination lotion (RSDL) for the decontamination of chemical warfare agent (CWA) dermal exposure.

    Science.gov (United States)

    Schwartz, M D; Hurst, C G; Kirk, M A; Reedy, S J D; Braue, E H

    2012-08-01

    Rapid decontamination of the skin is the single most important action to prevent dermal absorption of chemical contaminants in persons exposed to chemical warfare agents (CWA) and toxic industrial chemicals (TICs) as a result of accidental or intentional release. Chemicals on the skin may be removed by mechanical means through the use of dry sorbents or water. Recent interest in decontamination systems which both partition contaminants away from the skin and actively neutralize the chemical has led to the development of several reactive decontamination solutions. This article will review the recently FDA-approved Reactive Skin Decontamination Lotion (RSDL) and will summarize the toxicity and efficacy studies conducted to date. Evidence of RSDL's superior performance against vesicant and organophosphorus chemical warfare agents compared to water, bleach, and dry sorbents, suggests that RSDL may have a role in mass human exposure chemical decontamination in both the military and civilian arenas.

  17. [Decontamination of chemical warfare agents by photocatalysis].

    Science.gov (United States)

    Hirakawa, Tsutomu; Mera, Nobuaki; Sano, Taizo; Negishi, Nobuaki; Takeuchi, Koji

    2009-01-01

    Photocatalysis has been widely applied to solar-energy conversion and environmental purification. Photocatalyst, typically titanium dioxide (TiO(2)), produces active oxygen species under irradiation of ultraviolet light, and can decompose not only conventional pollutants but also different types of hazardous substances at mild conditions. We have recently started the study of photocatalytic decontamination of chemical warfare agents (CWAs) under collaboration with the National Research Institute of Police Science. This article reviews environmental applications of semiconductor photocatalysis, decontamination methods for CWAs, and previous photocatalytic studies applied to CWA degradation, together with some of our results obtained with CWAs and their simulant compounds. The data indicate that photocatalysis, which may not always give a striking power, certainly helps detoxification of such hazardous compounds. Unfortunately, there are not enough data obtained with real CWAs due to the difficulty in handling. We will add more scientific data using CWAs in the near future to develop useful decontamination systems that can reduce the damage caused by possible terrorism.

  18. Room Temperature Gas Sensing Properties of Sn-Substituted Nickel Ferrite (NiFe2O4) Thin Film Sensors Prepared by Chemical Co-Precipitation Method

    Science.gov (United States)

    Manikandan, V.; Li, Xiaogan; Mane, R. S.; Chandrasekaran, J.

    2018-04-01

    Tin (Sn) substituted nickel ferrite (NiFe2O4) thin film sensors were prepared by a simple chemical co-precipitation method, which initially characterized their structure and surface morphology with the help of x-ray diffraction and scanning electron microscopy. Surface morphology of the sensing films reveals particles stick together with nearer particles and this formation leads to a large specific area as a large specific area is very useful for easy adsorption of gas molecules. Transmission electron microscopy and selected area electron diffraction pattern images confirm particle size and nanocrystallnity as due to formation of circular rings. Fourier transform infrared analysis has supported the presence of functional groups. The 3.69 eV optical band gap of the film was found which enabled better gas sensing. Gas sensors demonstrate better response and recovery characteristics, and the maximum response was 68.43%.

  19. Synthesis and characterization of polyethylene glycol (PEG) coated Fe3O4 nanoparticles by chemical co-precipitation method for biomedical applications.

    Science.gov (United States)

    Anbarasu, M; Anandan, M; Chinnasamy, E; Gopinath, V; Balamurugan, K

    2015-01-25

    Polyethylene glycol (PEG) coated Fe3O4 nanoparticles were synthesized by chemical co-precipitation method. With polyethylene glycol (PEG) as a stabilizer and dispersant. The X-ray diffraction and selected area electron diffraction (SAED) results show that the cubic inverse spinel structure of pure phase polycrystalline Fe3O4 was obtained. The scanning electron microscopy (SEM) and field emission transmission electron microscopy (FE-TEM) results exhibited that the resulted Fe3O4 nanoparticles were roughly spherical in shape with narrow size distribution and homogenous shape. Fourier transform infrared spectroscopy (FT-IR) results suggested that PEG indicated with Fe3O4 via its carbonyl groups. Results of vibrating sample magnetometer (VSM) indicated that the prepared Fe3O4 nanoparticles exhibit superparamagnetic behavior and high saturation magnetization at room temperature. Such Fe3O4 nanoparticles with favorable size and tunable magnetic properties are promising biomedical applications. Copyright © 2014. Published by Elsevier B.V.

  20. System for chemical decontamination of nuclear reactor primary systems

    International Nuclear Information System (INIS)

    Schlonski, J.S.; McGiure, M.F.; Corpora, G.J.

    1992-01-01

    This patent describes a method of chemically decontaminating a nuclear reactor primary system, having a residual heat removal system with one or more residual heat removal heat exchangers, each having an upstream and a downstream side, at or above ambient pressure. It comprises: injecting decontamination chemicals using an injection means; circulating the injected decontamination chemicals throughout the primary system; directing the circulated decontamination chemicals and process fluids to a means for removing suspended solids and dissolved materials after the circulated chemicals and process fluids have passed through the residual heat removal heat exchanger; decontaminating the process fluids; and feeding the decontaminated process fluids to the injection means. This patent also describes a chemical decontamination system for use at, or above, ambient pressure in a nuclear reactor primary system having a residual heat removal system. It comprises: means for injecting decontamination chemicals into the primary system; means for removing dissolved and suspended materials and decontamination chemicals from the primary system; one or more residual heat removal pumps; means located downstream of one of the residual heat removal heat exchangers; and a return line connecting the means

  1. Chemical decontamination method for radioactive metal waste

    International Nuclear Information System (INIS)

    Tanaka, Akio; Onuma, Tsutomu; Yamazaki, Sei; Miura, Haruki.

    1993-01-01

    The present invention provides a chemical decontamination method for radioactive metal wastes, which are generated from radioactive material handling facilities and the surfaces of which are contaminated by radioactive materials. That is, it has a feature of applying acid dissolution simultaneously with mechanical grinding. The radioactive metal wastes are contained in a vessel such as a barrel together with abrasives in a sulfuric acid solution and rotated at several tens rotation per minute. By such procedures for the radioactive metal wastes, (1) cruds and passive membranes are mechanically removed, (2) exposed mother metal materials are uniformly brought into contact with sulfuric acid and further (3) the mother metal materials dissolve the cruds and the passive membranes also chemically by a reducing dissolution (so-called local cell effect). According to the method of the present invention, stainless steel metal wastes having cruds and passive membranes can rapidly and efficiently be decontaminated to a radiation level equal with that of ordinary wastes. (I.S.)

  2. Cost effectiveness of dilute chemical decontamination

    International Nuclear Information System (INIS)

    Le Surf, J.E.; Weyman, G.D.

    1983-01-01

    The origin and basic principles of the dilute chemical decontamination (DCD) concept are described and illustrated by reference to the CAN-DECON process. The estimated dose savings from the actual application of the process at several reactors are presented and discussed. Two methods of performing a cost/benefit appraisal are described and discussed. This methodology requires more study by the nuclear industry, including collection by station staff of relevant data on which future cost/benefit appraisals may be based. Finally, three illustrative cases are examinated to show the breakeven point and potential savings achievable by DCD with different initial radiation fields and different amounts of work to be done. The overall conclusion is that there are many situations in which DCD is desirable to reduce radiation exposure of workers, to save costs to the station, and to ease the performance of maintenance and repair work on reactor systems

  3. Transport and Reactivity of Decontaminants to Provide Hazard Mitigation of Chemical Warfare Agents from Materials

    Science.gov (United States)

    2016-06-01

    2013 4. TITLE AND SUBTITLE Transport and Reactivity of Decontaminants to Provide Hazard Mitigation of Chemical Warfare Agents from Materials 5a...directions for future decontamination formulation approaches. 15. SUBJECT TERMS GD HD Decontamination Hazard mitigation VX Chemical warfare agent... DECONTAMINANTS TO PROVIDE HAZARD MITIGATION OF CHEMICAL WARFARE AGENTS FROM MATERIALS 1. INTRODUCTION Decontamination of materials is the

  4. A review of chemical decontamination systems for nuclear facilities

    International Nuclear Information System (INIS)

    Chen, L.; Chamberlain, D.B.; Conner, C.; Vandegrift, G.F.

    1996-01-01

    With the downsizing of the Department of Energy (DOE) complex, many of its buildings and facilities will be decommissioned and dismantled. As part of this decommissioning, some form of decontamination will be required. To develop an appropriate technology for in situ chemical decontamination of equipment interiors in the decommissioning of DOE nuclear facilities, knowledge of the existing chemical decontamination methods is needed. This paper attempts to give an up-to-date review of chemical decontamination methods. This survey revealed that aqueous systems are the most widely used for the decontamination and cleaning of metal surfaces. We have subdivided the aqueous systems by types of chemical solvent: acid, alkaline permanganate, highly oxidizing, peroxide, and proprietary. Two other systems, electropolishing and foams and gels, are also described in this paper

  5. Review of decontamination technologies for chemical counter-terrorism

    Energy Technology Data Exchange (ETDEWEB)

    Volchek, K.; Boudreau, L.; Hornof, M. [SAIC Canada, Ottawa, ON (Canada); Fingas, M.F.; Gamble, R.L. [Environment Canada, Ottawa, ON (Canada). Emergencies Science and Technology Div]|[Environment Canada, Ottawa, ON (Canada). River Road Environmental Technology Centre

    2004-07-01

    The two categories of chemical agents that could be used in acts of chemical terrorism are conventional chemical warfare agents and commercial toxic chemicals. Industrial chemicals are easier to access than warfare agents, and must therefore be considered when evaluating decontamination techniques. This study involved a search of public-domain documents to identify decontamination technologies including: physical/mechanical treatment or removal; chemical treatment; and, biological methods including natural degradation and attenuation. The technologies were analyzed with reference to their effectiveness for specific groups of chemical agents, state of development, availability and costs. Results indicate that there are many decontamination methods available, both developed and under development, that work effectively for most agents. The two most common decontamination methods are oxidation and alkali hydrolysis followed by dehalogenation. Technology limitations and gaps were also identified, suggesting a need for more research to further the development of promising processes. 31 refs., 2 tabs.

  6. Building surface decontamination for chemical counter-terrorism

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, S.; Thouin, G.; Kuang, W. [SAIC Canada, Ottawa, ON (Canada); Volchek, K.; Fingas, M.; Li, K. [Environment Canada, Ottawa, ON (Canada). Emergencies Science and Technology Division, Environmental Technology Centre, Science and Technology Branch

    2006-07-01

    A test method to compare and evaluate surface decontamination methods for buildings affected by chemical attacks was developed. Decontamination techniques generally depend on the nature and quantity of the weapon agent, the type of construction material and the location. Cleanup methods can be either physical, chemical or biological. This paper addressed chemical decontamination methods which use reactants to change the molecular structure of the contaminant. Peroxycarboxylic and peroxyacetic acids (PAA) are being used increasingly for both disinfection and environmental protection. In this study, 4 materials were chosen to represent common building materials. Samples were spiked with 10 mg of pesticides such as malathion and diazinon. Decontamination agents included the commercial decontamination agent CASCAD prepared in liquid form, a chemical preparation of PAA, and reagent grade peroxypropionic acid (PPA). The newly developed surface decontamination procedure can evaluate and compare the effectiveness of different chemical decontamination agents. The procedures were used on porous ceiling tile and carpet as well as on non-porous floor tile and painted steel surfaces. Rinse water was collected and analyzed in order to determine if decontamination was a result of chemical destruction or mechanical removal. The extraction efficiencies were found to be acceptable for all materials, with the exception of the highly porous ceiling tile. The extraction of diazinon from all surfaces was less efficient than the extraction of malathion. Results suggest that the performance of decontamination agents can be improved by repeated application of the decontamination agent, along with greater volumes and a combination of chemical and mechanical actions. It was also suggested that breakdown methods and wastewater treatment procedures should be developed because hazardous byproducts were detected in many samples. 18 refs., 1 tab., 17 figs.

  7. Studies on residue-free decontaminants for chemical warfare agents.

    Science.gov (United States)

    Wagner, George W

    2015-03-17

    Residue-free decontaminants based on hydrogen peroxide, which decomposes to water and oxygen in the environment, are examined as decontaminants for chemical warfare agents (CWA). For the apparent special case of CWA on concrete, H2O2 alone, without any additives, effectively decontaminates S-2-(diisopropylamino)ethyl O-ethyl methylphosphonothioate (VX), pinacolyl methylphosphorofluoridate (GD), and bis(2-choroethyl) sulfide (HD) in a process thought to involve H2O2 activation by surface-bound carbonates/bicarbonates (known H2O2 activators for CWA decontamination). A plethora of products are formed during the H2O2 decontamination of HD on concrete, and these are characterized by comparison to synthesized authentic compounds. As a potential residue-free decontaminant for surfaces other than concrete (or those lacking adsorbed carbonate/bicarbonate) H2O2 activation for CWA decontamination is feasible using residue-free NH3 and CO2 as demonstrated by reaction studies for VX, GD, and HD in homogeneous solution. Although H2O2/NH3/CO2 ("HPAC") decontaminants are active for CWA decontamination in solution, they require testing on actual surfaces of interest to assess their true efficacy for surface decontamination.

  8. Chemical and mechanical decontamination processes to minimize secondary waste decommissioning

    International Nuclear Information System (INIS)

    Enda, M.; Ichikawa, N.; Yaita, Y.; Kanasaki, T.; Sakai, H.

    2008-01-01

    In the decommissioning of commercial nuclear reactors in Japan, prior to the dismantling of the nuclear power plants, there are plans to use chemical techniques to decontaminate reactor pressure vessels (RPVs), internal parts, primary loop recirculation systems (PLRs), reactor water clean up systems (RWCUs), etc., so as to minimize radiation sources in the materials to be disposed of. After dismantling the nuclear power plants, chemical and mechanical decontamination techniques will then be used to reduce the amounts of radioactive metallic waste. Toshiba Corporation has developed pre-dismantling and post-dismantling decontamination systems. In order to minimize the amounts of secondary waste, the T-OZON process was chosen for decontamination prior to the dismantling of nuclear power plants. Dismantling a nuclear power plant results in large amounts of metallic waste requiring decontamination; for example, about 20,000 tons of such waste is expected to result from the dismantling of a 110 MWe Boiling Water Reactor (BWR). Various decontamination methods have been used on metallic wastes in preparation for disposal in consideration of the complexity of the shapes of the parts and the type of material. The materials in such nuclear power plants are primarily stainless steel and carbon steel. For stainless steel parts having simple shapes, such as plates and pipes, major sources of radioactivity can be removed from the surface of the parts by bipolar electrolysis (electrolyte: H 2 SO 4 ). For stainless steel parts having complicated shapes, such as valves and pumps, major sources of radioactivity can be removed from the surfaces by redox chemical decontamination treatments (chemical agent: Ce(IV)). For carbon steel parts having simple shapes, decontamination by blasting with zirconia grit is effective in removing major sources of radioactivity at the surface, whereas for carbon steel parts having complicated shapes, major sources of radioactivity can be removed from

  9. Chemical decontamination method for stainless steel

    International Nuclear Information System (INIS)

    Yomo, Nobuo; Onuma, Tsutomu; Akimoto, Hidetoshi.

    1991-01-01

    In a case where an object to be decontaminated has a restricted portion in which the passage of liquids is difficult, decontamination liquids are not circulated effectively upon decontamination for the inner surfaces, and it requires a quite long period of time. In view of the above, through holes are perforated by, for example, a drill in the restricted portion of metal wastes made of stainless steels. Then, they are immersed in a sulfuric acid solution, and further immersed in an aqueous solution in which oxidative metal salts are added to the sulfuric acid. With such procedures, substrates are exposed at the inner circumference of the holes even if they are fine holes, and a local cell is formed between the substrate and an oxidized membranes, which may cause dissolution due to the reduction of the oxidized membranes. Further, since it is possible to discharge bubbles formed upon the solution, even from such fine holes, decontamination can be conducted effectively. (T.M.)

  10. Chemical decontamination of non-dismounted equipment of nuclear power stations

    International Nuclear Information System (INIS)

    Oertel, K.; Dietrich, P.; Hildebrandt, N.

    1979-01-01

    Reasons for performing system chemical decontaminations are considered, some cases of practical application to water cooled power reactors are discussed, radical and soft decontamination techniques are compared with each other, and evaluation criteria for decontaminations are studied. (author)

  11. Role reductants in dilute chemical decontamination formulations

    Energy Technology Data Exchange (ETDEWEB)

    Ranganathan, S. [Univ. of New Brunswick (Canada). Dept. of Chemical Engineering; Srinivasan, M.P.; Narasimhan, S.V. [Bhabha Atomic Research Centre (BARC), Trombay, Mumbai (India). Water and Steam Chemistry Lab.; Raghavan, P.S. [Madras Christian Coll., Chennai (India); Gopalan, R. [Madras Christian Coll., Chennai (India). Dept. of Chemistry

    2004-10-01

    Iron(III) oxides are the major corrosion products formed in boiling water reactors. The iron(III) oxides are of two types, namely hematite ({alpha}-Fe{sub 2}O{sub 3}) and maghemite ({gamma}-Fe{sub 2}O{sub 3}). The dissolution of these oxides is in no way simple because of the labile nature of the Fe(III)-O bond towards the chelants. The leaching of metal ions is partially controlled by reductive dissolution. In order to understand the role of the reductant, it is essential to study the dissolution behaviour of a system like Fe{sub 2}O{sub 3}, which does not contain any Fe{sup 2+} in the crystal lattice. The present study was carried out with {gamma}-Fe{sub 2}O{sub 3} and dilute chemical decontamination (DCD) formulations containing ascorbic acid and citric acid with the addition of Fe(II)-L as a reductant. The chelants used for the dissolution process were nitrilotriacetic acid, 2,6-pyridinedicorboxylic acid and ethylenediaminetetraacetic acid. The {gamma}-Fe{sub 2}O{sub 3} was chosen since the earlier studies revealed that the dissolution kinetics of {alpha}-Fe{sub 2}O{sub 3} is slow and it is difficult to dissolve even by strong complexing agents, whereas {gamma}-Fe{sub 2}O{sub 3} dissolution is comparatively easier. This is due to the structural difference between these two oxides. The studies also revealed that the dissolution was partly influenced by the nature of the chelating agents but mainly controlled by the power of the reductants used in the formulation. The dissolution behaviour of {gamma}-Fe{sub 2}O{sub 3} under various experimental conditions is discussed and compared with that of magnetite in order to arrive at a suitable mechanism for the dissolution of iron oxides and emphasize the role of reductants in DCD formulations. (orig.)

  12. Chemical hazards from decontamination solutions in low level waste

    International Nuclear Information System (INIS)

    Leventhal, L.; Miller, A.; Turney, J.; Naughton, M.; IMPELL Corp., Walnut Creek, CA; Electric Power Research Inst., Palo Alto, CA)

    1985-01-01

    Recent regulations are focussing more attention on the non-radioactive matrix materials associated with radioactive wastes. Decontamination of operating facilities is becoming a more significant source of low-level waste. This study reviewed the chemical and biological hazards of over 50 decontamination processes. Seventeen of the most prominent hard and soft decontamination processes were examined in detail. The chemical and biological hazards of these seventeen are presented in this paper. These hazards influence the choice of radwaste processing and packaging operations and methods. Federal, state and local regulations further impact on operations and waste disposal. Hazards to personnel, in plant and off-site, resulting from the decontamination cycle are evaluated. 1 fig., 5 tabs

  13. New decontamination techniques: chemical gels, electropolishing and abrasives

    International Nuclear Information System (INIS)

    Brunel, G.; Gauchon, J.P.; Kervegant, Y.; Josso, F.

    1991-01-01

    The decommissioning of nuclear installations requires decontamination techniques that are efficient, simple to apply and producing a small amount of wastes, which are easy to process. With a view to this, three decontamination methods, which appear to be particularly suited to decommissioning, have been studied. These three methods are: - spraying of gels carrying chemical decontaminating agents, - electropolishing with a swab device, - abrasives blasting. After parametric tests on non-radioactive and active samples, the industrial application of these methods in the dismantling of installations was studied. These industrial applications concern: - decontamination of pieces coming from the German BWR ISAR by immersion and gel spraying, - decontamination, mainly by gel spraying, and dismantling of the BRENNILIS bituminisation plant, - decontamination of part of the cooling circuit of the graphite gas reactor G2 by gel spraying, - decontamination of a component of the FBR SuperPhenix, using dry abrasives blasting. During the first three applications, generated secondary wastes volume and form were determined. 33 tabs., 16 figs., 12 refs

  14. Decontamination by water jet, chemical and electrochemical methods

    International Nuclear Information System (INIS)

    Gauchon, J.P.; Mordenti, P.; Bezia, C.; Fuentes, P.; Kervegant, Y.; Munoz, C.; Pierlas, C.

    1986-01-01

    The decontamination tests have been carried out on samples coming from representative specimens from primary circuit of the PWR and on samples coming from the emergency feed water piping of the German BWR (Isar). The oxide found in PWR primary loops can only be removed by a two steps process. The initial embrittling step is particularly effective in hot alkaline permanganate medium. Oxidation by ozone treatment is less effective. The second step involves chemical erosion of the metal in nitrofluoric acid in conjonction with ultrasonic agitation. Among the reagents used, only oxalic acid is suitable for electrolytic decontamination. Among the reagents possible for decontamination of the Isar specimens (ferritic steel lined with hematite) halogenous acid in mixture without or with oxygenated water, sulfuric acid, the formic acid/formaldehyde mixture are chosen. Metal erosion with high pressure jet as well as the decontamination efficiency on parts lined with hematite have made possible to determine the best conditions. 33 figs, 29 refs

  15. Method to chemically decontaminate nuclear reactor components

    International Nuclear Information System (INIS)

    Bertholdt, H.O.

    1984-01-01

    The large decontamination of components of the primary circuit of activated corrosion products in the oxide layer of the structure materials firstly involves an approx. 1 hour oxidation treatment with alkali permanganate solution. Following intermediate rinsing with deionate, they are etched with an inhibited citrate-oxalate solution for 5-20 hours. This is followed by post-treatment with a citric acid/H2O2 solution containing suspended fiber particles. (orig./PW)

  16. Decontamination

    International Nuclear Information System (INIS)

    Montford, B.

    1975-01-01

    Development of special techniques has permitted the use of mild decontamination processes for the CANDU type reactor primary coolant circuit, overcoming many of the problems associated with conventional decontamination processes, which use strong, acidic reagents. (Author)

  17. Binding affinity and decontamination of dermal decontamination gel to model chemical warfare agent simulants.

    Science.gov (United States)

    Cao, Yachao; Elmahdy, Akram; Zhu, Hanjiang; Hui, Xiaoying; Maibach, Howard

    2018-05-01

    Six chemical warfare agent simulants (trimethyl phosphate, dimethyl adipate, 2-chloroethyl methyl sulfide, diethyl adipate, chloroethyl phenyl sulfide and diethyl sebacate) were studied in in vitro human skin to explore relationship between dermal penetration/absorption and the mechanisms of simulant partitioning between stratum corneum (SC) and water as well as between dermal decontamination gel (DDGel) and water. Both binding affinity to and decontamination of simulants using DDGel were studied. Partition coefficients of six simulants between SC and water (Log P SC/w ) and between DDGel and water (Log P DDGel/w ) were determined. Results showed that DDGel has a similar or higher binding affinity to each simulant compared to SC. The relationship between Log P octanol/water and Log P SC/w as well as between Log P octanol/water and Log P DDGel/w demonstrated that partition coefficient of simulants correlated to their lipophilicity or hydrophilicity. Decontamination efficiency results with DDGel for these simulants were consistent with binding affinity results. Amounts of percentage dose of chemicals in DDGel of trimethyl phosphate, dimethyl adipate, 2-chloroethyl methyl sulfide, diethyl adipate, chloroethyl phenyl sulfide and diethyl sebacate were determined to be 61.15, 85.67, 75.91, 53.53, 89.89 and 76.58, with corresponding amounts absorbed in skin of 0.96, 0.65, 1.68, 0.72, 0.57 and 1.38, respectively. In vitro skin decontamination experiments coupled with a dermal absorption study demonstrated that DDGel can efficiently remove chemicals from skin surface, back-extract from the SC, and significantly reduced chemical penetration into skin or systemic absorption for all six simulants tested. Therefore, DDGel offers a great potential as a NextGen skin Decon platform technology for both military and civilian use. Copyright © 2018 John Wiley & Sons, Ltd.

  18. Effect of Organic Solvents in Preparation of Silica-Based Chemical Gel Decontaminates for Decontamination of Nuclear Facilities

    International Nuclear Information System (INIS)

    Yoon, Suk Bon; Jung, Chong Hun; Kim, Chang Ki; Choi, Byung Seon; Lee, Kune Woo; Moon, Jei Kwon

    2011-01-01

    Decontamination of nuclear facilities is necessary to reduce the radiation field during normal operations and decommissioning of complex equipment such as stainless steel components, other iron-based steel and alloys, metal surfaces, structural materials and so on. Chemical decontamination technology in particular is a highly effective method to remove the radioactive contamination through a chemical dissolution or a redox reaction. However, this method has the serious drawback due to the generation of large amounts of the radioactive liquid wastes. Recently, a few literatures have been reported for the preparation of the chemical gel decontaminants to reduce the amount of the radioactive liquid wastes and to enhance the decontamination efficiency through increasing the contact time between the gels and the radioactive contaminants. In the preparation of the chemical gels, the control of the viscosity highly depends on the amount of a coviscosifier used among the components of the chemical gels consisted of a viscosifier, a coviscosifier, and a chemical decontaminant. In this works, a new effective method for the preparation of the chemical gel was investigated by introducing the organic solvents. The mixture solution of the coviscosifier and organic solvent was more effective in the control of the viscosity compared with that of the coviscosifier only in gels. Furthermore, the decontamination efficiency of the chemical gels measured by using the multi-channel analyzer (MCA) showed the high decontamination factor for Co-60 and Cs-137 contaminated on the surface of the stainless steel 304

  19. Dilute chemical decontamination resins and the mixed waste issue

    International Nuclear Information System (INIS)

    Denault, R.P.; Hallman, J.T.

    1988-01-01

    The decontamination of reactor primary systems, sub-systems and components is an important method used to reduce the occupational radiation exposure of nuclear plant personnel. The waste produced by the application of this technology is mainly solid in the form of ion exchange resins. As a result of a recent agreement between the Environmental Protection Agency (EPA) and the Nuclear Regulatory Commission (NRC), all radioactive waste must meet EPA burial criteria. The chemicals used in a decontamination and certain metals dissolved during the process, primarily chromium, could render the waste hazardous as well as radioactive or more commonly called a mixed waste. This paper defines mixed waste as described in the EPA directive 9432.00-2, and examine the criteria by which waste is categorized as hazardous. The decontamination waste resin generated by two processes, the CAN-DEREM and the LOMI process, is described in detail. Waste data obtained from decontaminations performed by LN Technologies Corporation including chemical, metal and radionuclide loadings on resins from both PWR and BWR applications are presented

  20. Chemical Decontamination of Metallic Waste from Uranium Conversion Plant Dismantling

    International Nuclear Information System (INIS)

    Hwang, D. S.; Choi, Y. D.; Hwang, S. T.; Park, J. H.; Byun, J. I.; Jang, N. S.

    2005-01-01

    Korea Atomic Energy Research Institute (KAERI) started a decommissioning program of the uranium conversion plant. Pre-work was carried as follows; installation of the access control facility, installation of a changing room and shower room, designation of an emergency exit way and indicating signs, installation of a radiation management facility, preparation of a storage area for tools and equipments, inspection and load test of crane, distribution and packaging of existing waste, and pre-decontamination of the equipment surface and the interior. First, decommissioning work was performed in kiln room, which will be used for temporary radioactive waste storage room. Kiln room housed hydro fluorination rotary kiln for production of uranium tetra-fluoride. The kiln is about 0.8 m in diameter and 5.5 m long. The total dismantled waste was 6,690 kg, 73 % of which was metallic waste and 27 % the others such as cable, asbestos, concrete, secondary waste, etc. And effluent treatment room and filtration room were dismantled for installation of decontamination equipment and lagoon sludge treatment equipment. There were tanks and square mixer in these rooms. The total dismantled waste was 17,250 kg, 67% of which was metallic waste and 33% the others. These dismantled metallic wastes consist of stainless and carbon steel. In this paper, the stainless steel plate and pipe were decontaminated by the chemical decontamination with ultrasonic

  1. Aggressive chemical decontamination tests on small valves from the Garigliano BWR

    International Nuclear Information System (INIS)

    Bregani, F.

    1990-01-01

    In order to check the effectiveness of direct chemical decontamination on small and complex components, usually considered for storage without decontamination because of the small amount, some tests were performed on the DECO experimental loop. Four small stainless steel valves from the primary system of the Garigliano BWR were decontaminated using mainly aggressive chemicals such as HC1, HF, HNO 3 and their mixtures. On two valves, before the treatment with aggressive chemicals, a step with soft chemical (oxalic and citric acid mixture) was performed in order to see whether a softening action enhances the following aggressive decontamination. Moreover, in order to increase as much as possible the decontamination effectiveness, a decontamination process using ultrasounds jointly with aggressive chemicals was investigated. After an intensive laboratory testing programme, two smaller stainless steel valves from the primary system of the Garigliano BWR were decontaminated using ultrasounds in aggressive chemical solutions

  2. Method of heat decomposition for chemical decontaminating resin waste

    International Nuclear Information System (INIS)

    Kikuchi, Akira.

    1988-01-01

    Purpose: To make resin wastes into non-deleterious state, discharge them into a resin waste storage tank of existent radioactive waste processing facility and store and dispose them. Constitution: In the processing of chemical decontaminating resin wastes, iron exchange resins adsorbing chemical decontaminating agents comprising a solution of citric acid, oxalic acid, formic acid and EDTA alone or as a mixture of them are heated to dry, thermally decomposed and then separated from the ion exchange resins. That is, the main ingredients of the chemical decontaminating agents are heat-decomposed when heated and dried at about 250 deg C in air and converted into non-toxic gases such as CO, CO 2 , NO, NO 2 or H 2 O. Further, since combustion or carbonization of the basic materials for the resin is not caused at such a level of temperature, the resin wastes removed with organic acid and chelating agents are transferred to an existent resin waste storage tank and stored therein. In this way, facility cost and radiation exposure can remarkably be decreased. (Kamimura, M.)

  3. Full system chemical decontamination used in nuclear decommissioning

    International Nuclear Information System (INIS)

    Elder, George; Rottner, Bernard; Braehler, Georg

    2012-01-01

    The decommissioning of nuclear power stations at the end of the operational period of electricity generation offers technical challenges in the safe dismantling of the facility and the minimization of radioactive waste arising from the decommissioning activities. These challenges have been successfully overcome as demonstrated by decommissioning of the first generation of nuclear power plants. One of the techniques used in decommissioning is that of chemical decontamination which has a number of functions and advantages as given here: 1. Removal of contamination from metal surfaces in the reactors cooling systems. 2. Reduction of radioactive exposure to decommissioning workers 3. Minimization of metal waste by decontamination and recycling of metal components 4. Control of contamination when dismantling reactor and waste systems 5. Reduction in costs due to lower radiation fields, lower contamination levels and minimal metal waste volume for disposal. One such chemical decontamination technology was developed for the Electric Power Research Institute (EPRI) by Bradtec (Bradtec is an ONET Technologies subsidiary) and is known as the EPRI DFD system. This paper gives a description of the EPRI DFD system, and highlights the experience using the system. (orig.)

  4. Development of waste minimization and decontamination technologies at the Idaho Chemical Processing Plant

    International Nuclear Information System (INIS)

    Ferguson, R.L.; Archibald, K.E.; Demmer, R.L.

    1995-01-01

    Emphasis on the minimization of decontamination secondary waste has increased because of restrictions on the use of hazardous chemicals and Idaho Chemical Processing Plant (ICPP) waste handling issues. The Lockheed Idaho Technologies Co. (LITCO) Decontamination Development Subunit has worked to evaluate and introduce new performed testing, evaluations, development and on-site demonstrations for a number of novel decontamination techniques that have not yet previously been used at the ICPP. This report will include information on decontamination techniques that have recently been evaluated by the Decontamination Development Subunit

  5. Systematic chemical decontamination using IF7 gas - 59036

    International Nuclear Information System (INIS)

    Hata, Haruhi; Yokoyama, Kaoru; Sugitsue, Noritake

    2012-01-01

    Since 1979, Uranium enrichment technology has been researched through the gas centrifuge method, at Ningyo-toge Environmental Engineering Center of Japan Atomic Energy Agency (JAEA). In addition, the Demonstration Plant, that is final stage test facilities, was operating continuously from 1988 to 2001. As a result, a lot of residues accumulated in the plant. Most of this accumulation was found be uranium intermediate fluoride. The basic decommission policy of JAEA is that equipments of gas centrifuge will be decontaminated by sulfuric acid immersion method for clearance and reuse. In our plan, approximately 90% of metals will be cleared and reused, and then the remaining 10% will be disposed of radioactive waste. We propose a combination of sulfuric acid immersion method and the systematic chemical decontamination as an efficient method for decontamination of uranium enrichment facilities. This paper focuses on the method and performance of systematic chemical decontamination using IF 7 gas. The following (Figure 1) shows our decommission policy and position of systematic chemical decontamination by IF 7 gas for uranium enrichment plant. The IF 7 treatment technique belongs to the systematic decontamination technology. It has the high performance decontamination technique for the plant that accumulates the uranium intermediate fluoride, such as UF 4 , UF 5 , U 2 F 9 , and U 4 F 17 , which exist in the uranium enrichment plant through the Gas Centrifuge, called GCF. The one of characteristics of the IF 7 treatment, the secondary waste is just an IF 5 and little residues. In addition, this IF 5 can be reused as materials for making new IF 7 gas. The IF 7 treatment can also be performed in the room temperature and very low pressure like a 10-45 hPa. Furthermore, the IF 7 treatment is a simple method using chemical reaction. For this reason, we hardly need to care about secondary reaction with the exception of the reaction with IF 7 gasand the uranium intermediate

  6. Development of Bicarbonate-Activated Peroxide as a Chemical and Biological Warfare Agent Decontaminant

    National Research Council Canada - National Science Library

    Richardson, David E

    2006-01-01

    ...) and other chemistry for the decontamination of chemical and biological warfare agents. The mechanism of formation of the active oxidant, peroxymonocarbonate, has been investigated in detail. New surfoxidants...

  7. Chemical decontamination of Santa Maria de Garona NPP recirculation loops

    Energy Technology Data Exchange (ETDEWEB)

    Coello, R. [Santa Maria de Garona NPP - NUCLENOR, S.A. (Spain)

    2002-07-01

    Santa Maria de Garona is a boiling water reactor (BWR-3) with a Primary Containment type Mark 1. Its electrical power is 466 Mw and began its commercial operation in 1971. The plant currently operates in 24 month cycles. The reactor water recirculation system (RWRS) is composed of two independent loops. Each of them has a one stage vertical centrifugal recirculation pump, with a nominal flow of 2020 l/s, and ten jet pumps. It is worthy of mention that in 1986 it was started to inject hydrogen into the feedwater (concentration = 0,3 mg/l) in order to implement the chemical condition known as hydrogen water chemistry (HWC) in the primary circuit. The objective was to create an electrochemical potential below -230 mV in the RWRS which is assumed to be low enough to mitigate the intergranular stress corrosion cracking phenomena (IGSCC) in the sensitized austenitic stainless steels. Later, in 1994, the hydrogen concentration in the feedwater was increased to 0,9 mg/l in order to obtain the protection's ECP in the bottom of the reactor vessel. This feedwater hydrogen concentration has been maintained since then. The nature of the oxides that are formed in the RWRS is strongly affected by the electrochemical conditions (ECP) which have been maintained in this system. It is frequent to find oxides like Fe{sub 2}O{sub 3} (hematite), Fe{sub 3}O{sub 4} (magnetite), NiFe{sub 2}O{sub 4} (trevorite), Cr{sub 2} FeO{sub 4} (chromite), Fe{sub 3-x-y} Cr{sub x} Ni{sub y} O{sub 4} (spinels), etc. However, it is normal to find a combination of all of them in various proportions, depending on the ECP established. Radioactive isotopes of the transition metals ({sup 60}Co, {sup 54}Mn, {sup 51}Cr, {sup 59}Fe, etc.) also participate in these oxides and contribute greatly to increase the dose rate in the circuit. The chemical decontamination processes are designed for the effective dissolution of the metallic oxides present and therefore the type of process to be applied will depend

  8. Improvement of solvents for chemical decontamination: nickel ferrites removal

    International Nuclear Information System (INIS)

    Figueroa, Carlos A.; Morando, Pedro J.; Blesa, Miguel A.

    1999-01-01

    Carboxylic acids are usually included in commercial solvents for the chemical cleaning and decontamination of metal surfaces from the oxide layers grown and/or deposited from high temperature water by corrosive process. In particular oxalic acid is included in second path of AP-Citrox method. However, in some cases, their use shows low efficiency. This fact is attributed to the special passivity of the mixed oxides as nickel ferrites. This work reports a kinetic study of dissolution of a synthetic nickel ferrite (NiFe 2 O 4 ) confronted with simple oxides (NiO and Fe 2 O 3 ) in mineral acids and oxalic acid. The dissolution factor and reaction rate were determined in several conditions (reactive concentrations, pH and added ferrous ions). Experimental data of dissolution (with and without Fe(II) added) show a congruent kinetic regime. Pure nickel oxide (NiO) is rather resistant to the attack by oxalic acid solutions, and ferrous ions do not accelerate dissolution. In fact, nickel oxide dissolves better by oxidative attack that takes advantage of the higher lability of Ni 3+ . It may be concluded that oxalic acid operates to dissolve iron, and the ensuing disruption of the solid framework accelerates the release of nickel. Our results point to use more reactive solvents in iron from mixed oxides and to the possibility of using one stage decontamination method. (author)

  9. Decontamination of nuclear facilities

    International Nuclear Information System (INIS)

    1982-01-01

    Thirty-seven papers were presented at this conference in five sessions. Topics covered include regulation, control and consequences of decontamination; decontamination of components and facilities; chemical and non-chemical methods of decontamination; and TMI decontamination experience

  10. Chemical decontamination for decommissioning - the Jose Cabrera (Zorita) NPP

    International Nuclear Information System (INIS)

    Madrid Garcia, F.; Holgado, A.; Pomar, C.; Gammon, Th.; Bradbury, D.

    2008-01-01

    The Jose Cabrera (Zorita) NPP is located in the Guadalajara province of Spain approximately 66 km northeast of Madrid. It is a single loop Westinghouse Pressurized Water Reactor (PWR) design cooled by the waters of the River Tajo. The plant was synchronized to the grid in 1968 and was permanently shutdown on April 30, 2006. UNION FENOSA Generacion has been the owner and operator of the plant and will hand over decommissioning activities to Empresa Nacional de Residuous Radiactivos, S.A. (ENRESA) in approximately two years. During the fall and winter of 2006, Westinghouse Electric Company performed a Full System Decontamination (FSD) in preparation for decommissioning activities. The FSD was performed on the Reactor Coolant System (RCS) including the Residual Heat Removal System (RHRS) and the Chemical Volume and Control System (CVCS). The FSD was performed to facilitate decommissioning activities by reducing general area dose rates and lowering contamination levels to reduce disposal costs. (authors)

  11. Chemical stability of reactive skin decontamination lotion (RSDL®).

    Science.gov (United States)

    Bogan, R; Maas, H J; Zimmermann, T

    2018-09-01

    Reactive Skin Decontamination Lotion (RSDL ® ) is used for the decontamination of Chemical Warfare Agents and Toxic Industrial Compounds after dermal exposure. It has to be stockpiled over a long period and is handled in all climatic zones. Therefore stability is an essential matter of concern. In this work we describe a study to the chemical stability of RSDL ® as basis for an estimation of shelf life. We analysed RSDL ® for the active ingredient 2,3-butandione monoxime (diacetylmonooxime, DAM), the putative degradation product dimethylglyoxime (DMG) and unknown degradation products by means of a reversed phase high pressure liquid chromatography (HPLC). Calculations were done according to the Arrhenius equation. Based on the temperature dependent rate constants, the time span was calculated, until defined threshold values for DAM and DMG subject to specification and valid regulations were exceeded. The calculated data were compared to the ones gathered from stockpiled samples and samples exposed during foreign mission. The decline of DAM followed first order kinetics, while formation of DMG could be described by zero order kinetics. The rate constants were distinctively temperature dependent. Calculated data were in good accordance to the measured ones from stockpile and mission. Based on a specified acceptable DAM-content of 90% and a valid threshold value of 0.1% (w/w) for the degradation product DMG, RSDL ® proved to be stable for at least four years if stored at the recommended conditions of 15°C-30°C. If continuously stored at higher temperatures shelf life will decrease markedly. Therefore RSDL ® is an object for risk orientated quality monitoring during storage. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Structural and luminescence properties of CaTiO{sub 3}:Eu{sup 3+} phosphor synthesized by chemical co-precipitation method for the application of solid state lighting devices

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Dhananjay Kumar, E-mail: dksism89@gmail.com; Manam, J., E-mail: jairam.manam@gmail.com [Department of Applied Physics, Indian School of Mines, Dhanbad-826004 (India)

    2016-05-06

    The present work report a series of trivalent Europium (Eu{sup 3+}) doped well crystallized perovskite CaTiO{sub 3} phosphors successfully synthesized by chemical co-precipitation method. The crystal structure was confirmed by X-ray diffraction (XRD) which is in good agreement with pure orthorhombic phase with space group Pbnm, and it also indicated that the incorporation of the dopant did not affect the crystal structure. The impact of doping on the photoluminescence performances of the sample has been investigated by emission, excitation, and diffuse reflectance spectra at the room temperature. Photoluminescence spectra of Eu{sup 3+} doped CaTiO{sub 3} nanophosphor revealed the characteristic emission peak around wavelength 618 nm in the visible region upon the excitation of near-UV light at wavelength 397 nm due to {sup 5}D{sub 0} → {sup 7}F{sub 2} transition in Eu{sup 3+}. It was further proved that the dipole– dipole interactions results in the concentration quenching of Eu{sup 3+} in CaTiO{sub 3}:Eu{sup 3+} nanophosphors. The elemental composition of sample carried out by energy dispersive spectroscopy (EDS). EDS analysis reveals that the Eu{sup 3+} doped successfully into host CaTiO{sub 3}. The experimental result reveals that prepared nanophosphor can be used in the application of solid state lighting devices.

  13. Comparison of Selected Methods for Individual Decontamination of Chemical Warfare Agents

    OpenAIRE

    Tomas Capoun; Jana Krykorkova

    2014-01-01

    This study addresses the individual decontamination of chemical warfare agents (CWA) and other hazardous substances. The individual decontamination applies to contaminated body surfaces, protective clothing and objects immediately after contamination, performed individually or by mutual assistance using prescribed or improvised devices. The article evaluates the importance of individual decontamination, security level for Fire and Rescue Service Units of the Czech Republic (FRS CR) and demons...

  14. Decontamination and management of human remains following incidents of hazardous chemical release.

    Science.gov (United States)

    Hauschild, Veronique D; Watson, Annetta; Bock, Robert

    2012-01-01

    To provide specific guidance and resources for systematic and orderly decontamination of human remains resulting from a chemical terrorist attack or accidental chemical release. A detailed review and health-based decision criteria protocol is summarized. Protocol basis and logic are derived from analyses of compound-specific toxicological data and chemical/physical characteristics. Guidance is suitable for civilian or military settings where human remains potentially contaminated with hazardous chemicals may be present, such as sites of transportation accidents, terrorist operations, or medical examiner processing points. Guidance is developed from data-characterizing controlled experiments with laboratory animals, fabrics, and materiel. Logic and specific procedures for decontamination and management of remains, protection of mortuary affairs personnel, and decision criteria to determine when remains are sufficiently decontaminated are presented. Established procedures as well as existing materiel and available equipment for decontamination and verification provide reasonable means to mitigate chemical hazards from chemically exposed remains. Unique scenarios such as those involving supralethal concentrations of certain liquid chemical warfare agents may prove difficult to decontaminate but can be resolved in a timely manner by application of the characterized systematic approaches. Decision criteria and protocols to "clear" decontaminated remains for transport and processing are also provided. Once appropriate decontamination and verification have been accomplished, normal procedures for management of remains and release can be followed.

  15. Chemical, biological, radiological, and nuclear decontamination: Recent trends and future perspective

    Directory of Open Access Journals (Sweden)

    Vinod Kumar

    2010-01-01

    Full Text Available Chemical, biological, radiological, and nuclear (CBRN decontamination is the removal of CBRN material from equipment or humans. The objective of the decontamination is to reduce radiation burden, salvage equipment, and materials, remove loose CBRN contaminants, and fix the remaining in place in preparation for protective storage or permanent disposal work activities. Decontamination may be carried out using chemical, electrochemical, and mechanical means. Like materials, humans may also be contaminated with CBRN contamination. Changes in cellular function can occur at lower radiation doses and exposure to chemicals. At high dose, cell death may take place. Therefore, decontamination of humans at the time of emergency while generating bare minimum waste is an enormous task requiring dedication of large number of personnel and large amount of time. General principles of CBRN decontamination are discussed in this review with emphasis on radiodecontamination.

  16. Wet milling versus co-precipitation in magnetite ferrofluid preparation

    Directory of Open Access Journals (Sweden)

    Almásy László

    2015-01-01

    Full Text Available Various uses of ferrofluids for technical applications continuously raise the interest in improvement and optimization of preparation methods. This paper deals with preparation of finely granulated magnetite particles coated with oleic acid in hydrocarbon suspensions following either chemical co-precipitation from iron salt precursors or wet milling of micron size magnetite powder with the goal to compare the benefits and disadvantages of each method. Microstructural measurements showed that both methods gave similar magnetite particle size of 10-15 nm. Higher saturation magnetization was achieved for the wet-milled magnetite suspension compared to relatively rapid co-precipitation synthesis. Different efficacies of ferrophase incorporation into kerosene could be related to the different mechanisms of oleic acid bonding to nanoparticle surface. The comparative data show that wet milling represents a practicable alternative to the traditional co-precipitation since despite of longer processing time, chemicals impact on environment can be avoided as well as the remnant water in the final product.

  17. Dresden Nuclear Power Station, Unit No. 1: Primary cooling system chemical decontamination: Draft environmental statement (Docket No. 50-10)

    International Nuclear Information System (INIS)

    1980-05-01

    The staff has considered the environmental impact and economic costs of the proposed primary cooling system chemical decontamination at Dresden Nuclear Power Station, Unit 1. The staff has focused this statement on the occupational radiation exposure associated with the proposed Unit 1 decontamination program, on alternatives to chemical decontamination, and on the environmental impact of the disposal of the solid radioactive waste generated by this decontamination. The staff has concluded that the proposed decontamination will not significantly affect the quality of the human environment. Furthermore, any impacts from the decontamination program are outweighed by its benefits. 2 figs., 7 tabs

  18. Chemical decontamination for decommissioning purposes. (Vigorous decontamination tests of steel samples in a special test loop)

    International Nuclear Information System (INIS)

    Bregani, F.; Pascali, R.; Rizzi, R.

    1984-01-01

    The aim of the research activities described was to develop vigorous decontamination techniques for decommissioning purposes, taking into account the cost of treatment of the radwaste, to achieve possibly unrestricted release of the treated components, and to obtain know-how for in situ hard decontamination. The decontamination procedures for strong decontamination have been optimized in static and dynamic tests (DECO-loop). The best values have been found for: (i) hydrochloric acid: 4 to 5% vol. at low temperature, 0.7 to 1% vol. at high temperature (80 0 C); (ii) hydrofluoric plus nitric acid: 1.5% vol. HF + 5% vol. HNO 3 at low temperature; 0.3 to 0.5% vol. HF + 2.5 to 5% vol. HNO 3 at high temperature. High flow rates are not necessary, but a good re-circulation of the solution is needed. The final contamination levels, after total oxide removal, are in accordance with limits indicated for unrestricted release of materials in some countries. The arising of the secondary waste is estimated. Decontamination of a 10 m 2 surface would typically produce 0.5 to 3.0 kg of dry waste, corresponding to 1.6 to 10 kg of concrete conditioned waste

  19. Comprehensive investigation of the corrosion and surface chemical effects of the decontamination technologies

    International Nuclear Information System (INIS)

    Szabo-Nagy, Andrea; Varga, Kalman; Deak-Horvath, Emese; Nemeth, Zoltan; Horvath, David; Schunk, Janos; Patek, Gabor

    2012-09-01

    Decontamination technologies are mainly developed to reduce the collective dose of the maintenance personnel at NPPs. The highest efficiency (i.e., the highest DF values) available without detrimental modification of the treated surface of structural material is the most important goal in the course of the application of a decontamination technology. A so-called 'soft' chemical decontamination technology has been developed - supported by the Paks Nuclear Power Plant - at the Institute of Radiochemistry and Radioecology of the University of Pannonia. The novel base technology can be effectively applied for the decontamination of the heat exchanger tubes of steam generators. In addition, by optimizing the main technological parameters (temperature, concentration of the liquid chemicals, flow rates, contact time, etc.) it can be utilized for specific applications such as decontamination of some dismountable devices and separable equipment or the total decontamination prior to plant dismantling (decommissioning) in the future. The aim of this work is to compare the efficiency, corrosion and surface chemical effects of some improved versions of the novel base-technology elaborated for decontamination of austenitic stainless steel surfaces. The experiments have been performed at laboratory conditions in decontamination model systems. The applied methods: γ-spectrometry, ICP-OES, voltammetry and SEM-EDX. The experimental results revealed that the efficiency of the base-technology mainly depends on the surface features of the stainless steel samples such as the chemical composition and thickness of the oxide layer, the nature (quantity, morphology and chemical composition) of the crystalline deposits. It has been documented that the improved version of the base-technology are suitable for the decontamination of both steel surfaces covered by chemically resistant large Cr-content crystals and that having compact oxide-layers (up to a thickness of 10

  20. Chemical warfare agent simulants for human volunteer trials of emergency decontamination: A systematic review

    OpenAIRE

    James, Thomas; Wyke, Stacey; Marczylo, Tim; Collins, Samuel; Gaulton, Tom; Foxall, Kerry; Amlôt, Richard; Duarte‐Davidson, Raquel

    2017-01-01

    Abstract Incidents involving the release of chemical agents can pose significant risks to public health. In such an event, emergency decontamination of affected casualties may need to be undertaken to reduce injury and possible loss of life. To ensure these methods are effective, human volunteer trials (HVTs) of decontamination protocols, using simulant contaminants, have been conducted. Simulants must be used to mimic the physicochemical properties of more harmful chemicals, while remaining ...

  1. Comparison of Selected Methods for Individual Decontamination of Chemical Warfare Agents

    Directory of Open Access Journals (Sweden)

    Tomas Capoun

    2014-06-01

    Full Text Available This study addresses the individual decontamination of chemical warfare agents (CWA and other hazardous substances. The individual decontamination applies to contaminated body surfaces, protective clothing and objects immediately after contamination, performed individually or by mutual assistance using prescribed or improvised devices. The article evaluates the importance of individual decontamination, security level for Fire and Rescue Service Units of the Czech Republic (FRS CR and demonstrates some of the devices. The decontamination efficiency of selected methods (sorbent, glove and sponge, two-chamber foam device and wiping with alcohol was evaluated for protective clothing and painted steel plate contaminated with O-ethyl-S-(diisopropylaminoethyl-methylthiophosphonate (VX, sulfur mustard, o-cresol and acrylonitrile. The methods were assessed from an economic point of view and with regard to specific user parameters, such as the decontamination of surfaces or materials with poor accessibility and vertical surfaces, the need for a water rinse as well as toxic waste and its disposal.

  2. A decontamination system for chemical weapons agents using a liquid solution on a solid sorbent.

    Science.gov (United States)

    Waysbort, Daniel; McGarvey, David J; Creasy, William R; Morrissey, Kevin M; Hendrickson, David M; Durst, H Dupont

    2009-01-30

    A decontamination system for chemical warfare agents was developed and tested that combines a liquid decontamination reagent solution with solid sorbent particles. The components have fewer safety and environmental concerns than traditional chlorine bleach-based products or highly caustic solutions. The liquid solution, based on Decon Greentrade mark, has hydrogen peroxide and a carbonate buffer as active ingredients. The best solid sorbents were found to be a copolymer of ethylene glycol dimethacrylate and n-lauryl methacrylate (Polytrap 6603 Adsorber); or an allyl methacrylate cross-linked polymer (Poly-Pore E200 Adsorber). These solids are human and environmentally friendly and are commonly used in cosmetics. The decontaminant system was tested for reactivity with pinacolyl methylphosphonofluoridate (Soman, GD), bis(2-chloroethyl)sulfide (Mustard, HD), and S-(2-diisopropylaminoethyl) O-ethyl methylphosphonothioate (VX) by using NMR Spectroscopy. Molybdate ion (MoO(4)(-2)) was added to the decontaminant to catalyze the oxidation of HD. The molybdate ion provided a color change from pink to white when the oxidizing capacity of the system was exhausted. The decontaminant was effective for ratios of agent to decontaminant of up to 1:50 for VX (t(1/2) decontamination solution were measured to show that the sorbent decreased the vapor concentration of GD. The E200 sorbent had the additional advantage of absorbing aqueous decontamination solution without the addition of an organic co-solvent such as isopropanol, but the rate depended strongly on mixing for HD.

  3. Recovery of sludge from the treatment of liquid radioactive effluents by co-precipitation with calcium carbonate: laboratory study; Recuperation des boues de traitement des effluents radioactifs liquides par coprecipitation avec le carbonate de calcium: etude de laboratoire

    Energy Technology Data Exchange (ETDEWEB)

    Patti, F.; Gailledreau, C.; Cohen, P.

    1961-02-24

    As during the treatment by co-precipitation with calcium carbonate of liquid radioactive residues, a partial decontamination can be obtained by simply agitating an already formed radioactive sludge with the effluent to be processed, the authors study whether it would be possible to first perform a co-precipitation with a lower dose of calcium carbonate and then to complete decontamination by agitating with an adequate quantity of sludge stored during preceding operations. The authors report the study of the influence of reactant quantity on the chemical treatment efficiency, of the evolution of the activity of a radioactive residual solution in contact with a precipitate, of the cleaner element, of a precipitate reuse, of the technological and economic aspects, and of another possibility of reduction of the precipitate volume [French] Dans le traitement par coprecipitation avec le carbonate de calcium des residus radioactifs liquides, une decontamination partielle peut etre obtenue en agitant simplement une boue radioactive deja formee avec l'effluent a traiter. En consequence, il pourrait etre possible d'effectuer d'abord une coprecipitation avec une dose plus faible de carbonate de calcium et de completer ensuite la decontamination en agitant le liquide avec une quantite convenable de boue stockee a partir d'operations precedentes. (auteurs)

  4. Decontamination of chemical agents from drinking water infrastructure: a literature review and summary.

    Science.gov (United States)

    Szabo, Jeff; Minamyer, Scott

    2014-11-01

    This report summarizes the current state of knowledge on the persistence of chemical contamination on drinking water infrastructure (such as pipes) along with information on decontamination should persistence occur. Decontamination options for drinking water infrastructure have been explored for some chemical contaminants, but important data gaps remain. In general, data on chemical persistence on drinking water infrastructure is available for inorganics such as arsenic and mercury, as well as select organics such as petroleum products, pesticides and rodenticides. Data specific to chemical warfare agents and pharmaceuticals was not found and data on toxins is scant. Future research suggestions focus on expanding the available chemical persistence data to other common drinking water infrastructure materials. Decontaminating agents that successfully removed persistent contamination from one infrastructure material should be used in further studies. Methods for sampling or extracting chemical agents from water infrastructure surfaces are needed. Published by Elsevier Ltd.

  5. A Survey and Evaluation of Chemical Warfare Agent-Decontaminants and Decontamination

    Science.gov (United States)

    1984-10-15

    Biological Methods. The use of a cell-free enzymatic system, microorganisms, algae, and the state-of-the-art genetic engineering approach for decontaminating...many organic and inorganic materials might react with agents in a manner similar to complex enzymatic reactions. However. experimental data were not...28). XXCC3 was further tested for use in a microencapsulation concept. Pre- liminary results indicated that O.30g of ethyl cellulose 21 microcapsules

  6. Efficacy of liquid and foam decontamination technologies for chemical warfare agents on indoor surfaces.

    Science.gov (United States)

    Love, Adam H; Bailey, Christopher G; Hanna, M Leslie; Hok, Saphon; Vu, Alex K; Reutter, Dennis J; Raber, Ellen

    2011-11-30

    Bench-scale testing was used to evaluate the efficacy of four decontamination formulations on typical indoor surfaces following exposure to the liquid chemical warfare agents sarin (GB), soman (GD), sulfur mustard (HD), and VX. Residual surface contamination on coupons was periodically measured for up to 24h after applying one of four selected decontamination technologies [0.5% bleach solution with trisodium phosphate, Allen Vanguard Surface Decontamination Foam (SDF™), U.S. military Decon Green™, and Modec Inc. and EnviroFoam Technologies Sandia Decontamination Foam (DF-200)]. All decontamination technologies tested, except for the bleach solution, performed well on nonporous and nonpermeable glass and stainless-steel surfaces. However, chemical agent residual contamination typically remained on porous and permeable surfaces, especially for the more persistent agents, HD and VX. Solvent-based Decon Green™ performed better than aqueous-based bleach or foams on polymeric surfaces, possibly because the solvent is able to penetrate the polymer matrix. Bleach and foams out-performed Decon Green for penetrating the highly polar concrete surface. Results suggest that the different characteristics needed for an ideal and universal decontamination technology may be incompatible in a single formulation and a strategy for decontaminating a complex facility will require a range of technologies. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Decontamination of the chemical crane room and decontamination and decommissioning of the extraction chemical room at the West Valley Demonstration Project

    International Nuclear Information System (INIS)

    Phillips, E.C.; Golden, M.P.

    1986-01-01

    This paper describes the decontamination of the Chemical Crane Room (CCR) of the West Valley Plant and the Extraction Chemical Room (XCR) from radioactively contaminated conditions to essentially shirt sleeve environments. In both cases, subsequent use re-contaminated the rooms. Prior to decontamination, general exposure rates in the CCR were 50 to 100 mR/hr with hot spots as high as 2000 mR/hr. Smearable levels on the floor were in the range of 10 5 to 10 6 dpm per 100/cm 2 . Respiratory protection was mandatory for entry. In the Extraction Chemical Room (XCR) prior to decontamination and decommissioning (D/D), radiological surveys indicated a maximum radiation field of 5 mR/hr, due to sources internal to the room, and 20,000 dpm beta/100 cm 2 surface contamination. A radiation source external to the XCR caused a hot spot with a 9 mR/hr exposure rate inside the XCR. The CCR, located at the north end of the Chemical Process Cell (CPC) is for the storage and servicing of two bridge cranes used in the CPC. Decontamination and exposure reduction in the CCR has been completed using vacuum cleaning, damp wipe down, and surface grinding followed by shielding and painting. The decontamination and decommissioning of the Extraction Chemical Room (XCR), located on the fifth floor elevation (160') of the reprocessing plant at the WVDP, has been completed. D/D operations included removal of piping, tanks, supports, and equipment to provide a clean work area of about 3000 square feet and 17 feet high

  8. The restoration project : decontamination of facilities from chemical, biological and radiological contamination after terrorist action

    Energy Technology Data Exchange (ETDEWEB)

    Fingas, M.; Volchek, K.; Thouin, G.; Harrison, S.; Kuang, W. [Environment Canada, Ottawa, ON (Canada). Emergencies Science Div; Velicogna, D.; Hornof, M.; Punt, M. [SAIC Canada, Ottawa, ON (Canada); Payette, P.; Duncan, L.; Best, M.; Krishnan; Wagener, S.; Bernard, K.; Majcher, M. [Public Health Agency of Canada, Ottawa, ON (Canada); Cousins, T.; Jones, T. [Defence Research and Development Canada, Ottawa, ON (Canada)

    2005-07-01

    Bioterrorism poses a real threat to the public health and national security, and the restoration of affected facilities after a chemical, biological or radiological attack is a major concern. This paper reviewed aspects of a project conducted to collect information, test and validate procedures for site restoration after a terrorist attack. The project began with a review of existing technology and then examined new technologies. Restoration included pickup, neutralization, decontamination, removal and final destruction and deposition of contaminants as well as cleaning and neutralization of material and contaminated waste from decontamination. The project was also intended to test existing concepts and develop new ideas. Laboratory scale experiments consisted of testing, using standard laboratory techniques. Radiation decontamination consisted of removal and concentration of the radioisotopes from removal fluid. General restoration guidelines were provided, as well as details of factors considered important in specific applications, including growth conditions and phases of microorganisms in biological decontamination, or the presence of inhibitors or scavengers in chemical decontamination. Various agents were proposed that were considered to have broad spectrum capability. Test surrogates for anthrax were discussed. The feasibility of enhanced oxidation processes was examined in relation to the destruction of organophosphorus, organochlorine and carbamate pesticides. The goal was to identify a process for the treatment of surfaces contaminated with pesticides. Tests included removal from carpet, porous ceiling tile, steel plates, and floor tiles. General radiation contamination procedures and techniques were reviewed, as well as radiological decontamination waste treatment. It was concluded that there is no single decontamination technique applicable for all contaminants, and decontamination methods depend on economic, social and health factors. The amount of

  9. Development of haemostatic decontaminants for the treatment of wounds contaminated with chemical warfare agents. 2: evaluation of in vitro topical decontamination efficacy using undamaged skin.

    Science.gov (United States)

    Dalton, Christopher H; Hall, Charlotte A; Lydon, Helen L; Chipman, J K; Graham, John S; Jenner, John; Chilcott, Robert P

    2015-05-01

    The risk of penetrating, traumatic injury occurring in a chemically contaminated environment cannot be discounted. Should a traumatic injury be contaminated with a chemical warfare (CW) agent, it is likely that standard haemostatic treatment options would be complicated by the need to decontaminate the wound milieu. Thus, there is a need to develop haemostatic products that can simultaneously arrest haemorrhage and decontaminate CW agents. The purpose of this study was to evaluate a number of candidate haemostats for efficacy as skin decontaminants against three CW agents (soman, VX and sulphur mustard) using an in vitro diffusion cell containing undamaged pig skin. One haemostatic product (WoundStat™) was shown to be as effective as the standard military decontaminants Fuller's earth and M291 for the decontamination of all three CW agents. The most effective haemostatic agents were powder-based and use fluid absorption as a mechanism of action to sequester CW agent (akin to the decontaminant Fuller's earth). The envisaged use of haemostatic decontaminants would be to decontaminate from within wounds and from damaged skin. Therefore, WoundStat™ should be subject to further evaluation using an in vitro model of damaged skin. Copyright © 2014 Crown copyright. Journal of Applied Toxicology © 2014 John Wiley & Sons, Ltd.

  10. Chemical warfare agent simulants for human volunteer trials of emergency decontamination: A systematic review.

    Science.gov (United States)

    James, Thomas; Wyke, Stacey; Marczylo, Tim; Collins, Samuel; Gaulton, Tom; Foxall, Kerry; Amlôt, Richard; Duarte-Davidson, Raquel

    2018-01-01

    Incidents involving the release of chemical agents can pose significant risks to public health. In such an event, emergency decontamination of affected casualties may need to be undertaken to reduce injury and possible loss of life. To ensure these methods are effective, human volunteer trials (HVTs) of decontamination protocols, using simulant contaminants, have been conducted. Simulants must be used to mimic the physicochemical properties of more harmful chemicals, while remaining non-toxic at the dose applied. This review focuses on studies that employed chemical warfare agent simulants in decontamination contexts, to identify those simulants most suitable for use in HVTs of emergency decontamination. Twenty-two simulants were identified, of which 17 were determined unsuitable for use in HVTs. The remaining simulants (n = 5) were further scrutinized for potential suitability according to toxicity, physicochemical properties and similarities to their equivalent toxic counterparts. Three suitable simulants, for use in HVTs were identified; methyl salicylate (simulant for sulphur mustard), diethyl malonate (simulant for soman) and malathion (simulant for VX or toxic industrial chemicals). All have been safely used in previous HVTs, and have a range of physicochemical properties that would allow useful inference to more toxic chemicals when employed in future studies of emergency decontamination systems. © 2017 Crown Copyright. Journal of Applied Toxicology published by John Wiley & Sons, Ltd.

  11. Reactor component chemical decontamination-developments in waste handling and disposal

    International Nuclear Information System (INIS)

    Papesch, R.; Atwood, K.L.

    1989-01-01

    Because of restrictive limits on man-rem exposure in European nuclear plants, a company has developed and applied a number of chemical decontamination techniques for components that must be periodically maintained. These techniques are particularly effective for components that can be placed in a decontamination bath for dose reduction prior to performing maintenance. The cleaning technique has the ability to achieve decontamination factors of at least 20 and in some cases much greater. For components with before cleaning dose rates of between 1 to as high as 80 R/hr, significant man-rem reductions are achieved when hundreds of manhours may be required to complete required component maintenance. Transferring this solvent technology to the U.S. required a program to develop solidification formulas to allow the solvent wastes to be disposed of in accordance with regulations and in a cost effective manner. This paper demonstrates in chemical decontaminations with small liquid volume systems that concentrated decontamination solvents can be employed to achieve high decontamination factors

  12. Evaluation of a dilute chemical decontaminant for pressurized heavy water reactors

    International Nuclear Information System (INIS)

    Velmurugan, S.; Narasimhan, S.V.; Mathur, P.K.; Venkateswarlu, K.S.

    1991-01-01

    In this paper a dilute chemical decontamination formulation based on ethylene diamine tetraacetic acid, oxalic acid, and citric acid is evaluated for its efficacy in removing oxide layers in a pressurized heavy water reactor (PHWR). An ion exchange system that is specifically suited for fission product-dominated contamination in a PHWR is suggested for the reagent regeneration stage of the decontamination process. An attempt has been made to understand the redeposition behavior of various isotopes during the decontamination process. The polarographic method of identifying the species formed in the dissolution process is explained. Electrochemical measurements are employed to follow the course of oxide removal during the dissolution process. Scanning electron micrographs of metal coupons before and after the dissolution process exemplify the involvement of base metal in the formation of a ferrous oxalate layer. Material compatibility tests between the decontaminant and carbon steel, Monel-400, and Zircaloy-2 are reported

  13. SAFETY STUDIES TO MEASURE EXOTHERMIC REACTIONS OF SPENT PLUTONIUM DECONTAMINATION CHEMICALS USING WET AND DRY DECONTAMINATION METHODS

    International Nuclear Information System (INIS)

    HOPKINS, A.M.; JACKSON, G.W.; MINETTE, M.; EWALT, J.; COOPER, T.; SCOTT, P.; JONES, S.; SCHEELEY, R.

    2005-01-01

    The Plutonium Finishing Plant (PFP) at the Hanford site in Eastern Washington is currently being decommissioned by Fluor Hanford. Chemicals being considered for dccontamination of gloveboxes in PFP include cerium (IV) nitrate in a nitric acid solution, and proprietary commercial solutions that include acids and sequestering agents. Aggressive chemicals are commonly used to remove transuranic contaminants from process equipment to allow disposal of the equipment as low level waste. Fluor's decontamination procedure involves application of chemical solutions as a spray on the contaminated surfaces, followed by a wipe-down with rags. Alternatively, a process of applying oxidizing Ce IV ions contained in a gel matrix and vacuuming a dry gel material is being evaluated. These processes effectively transfer the transuranic materials to rags or a gel matrix which is then packaged as TRU waste and disposed

  14. Next Generation Non-particulate Dry Nonwoven Pad for Chemical Warfare Agent Decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Ramkumar, S S; Love, A; Sata, U R; Koester, C J; Smith, W J; Keating, G A; Hobbs, L; Cox, S B; Lagna, W M; Kendall, R J

    2008-05-01

    New, non-particulate decontamination materials promise to reduce both military and civilian casualties by enabling individuals to decontaminate themselves and their equipment within minutes of exposure to chemical warfare agents or other toxic materials. One of the most promising new materials has been developed using a needlepunching nonwoven process to construct a novel and non-particulate composite fabric of multiple layers, including an inner layer of activated carbon fabric, which is well-suited for the decontamination of both personnel and equipment. This paper describes the development of a composite nonwoven pad and compares efficacy test results for this pad with results from testing other decontamination systems. The efficacy of the dry nonwoven fabric pad was demonstrated specifically for decontamination of the chemical warfare blister agent bis(2-chloroethyl)sulfide (H or sulfur mustard). GC/MS results indicate that the composite fabric was capable of significantly reducing the vapor hazard from mustard liquid absorbed into the nonwoven dry fabric pad. The mustard adsorption efficiency of the nonwoven pad was significantly higher than particulate activated carbon (p=0.041) and was similar to the currently fielded US military M291 kit (p=0.952). The nonwoven pad has several advantages over other materials, especially its non-particulate, yet flexible, construction. This composite fabric was also shown to be chemically compatible with potential toxic and hazardous liquids, which span a range of hydrophilic and hydrophobic chemicals, including a concentrated acid, an organic solvent and a mild oxidant, bleach.

  15. Development of chemical decontamination for low level radioactive wastes

    International Nuclear Information System (INIS)

    Ichikawa, Seigo; Omata, Kazuo; Obinata, Hiroshi; Nakajima, Yoshihiko; Kanamori, Osamu.

    1995-01-01

    During routine intermittent inspection and maintenance at nuclear power plants, a considerable quantity of low level radioactive waste is generated requiring release from the nuclear site or treating additionally. To decontaminate this waste for safe release from the nuclear power plant, the first step could be washing the waste in Methylene chloride, CH 2 Cl 2 , to remove most of the paint coating. However, CH 2 Cl 2 washing does not completely remove the paint coating from the waste, which in the next step is shot blasted with plastic bead media to loose and remove the remaining paint coating. Following in succession, in the third step, the waste is washed in a chelate solution, after which most waste is decontaminated and suitable to be released for recycling. The residual chelate solution may be decomposed into nontoxic carbon dioxide and water by an electrolysis process and then safely discharged into the environment. (author)

  16. Commercial Cleaning Products for Chemical Decontamination: A Scoping Study

    Science.gov (United States)

    2014-05-01

    and may injure human skin without dilution), although this approach is less favoured in a mass casualty decontamination situation than soap and water...commercial cleaning products, full strength K-O-K® liquid bleach (5.25% aqueous solution of NaOCl), dish-washing detergent Cascade® with Extra...Bleach Action Gel, OxiClean® Versatile Stain Remover Powder, and ZEP® Industrial Purple liquid cleaner (proprietary caustic cleaner containing

  17. Evaluation on Safety of Stainless Steels in Chemical Decontamination Process with Immersion Type of Reactor Coolant Pump for Nuclear Reactor

    International Nuclear Information System (INIS)

    Kim, Seong Jong; Han, Min Su; Jang, Seok Ki; Kim, Ki Joon

    2011-01-01

    Due to commercialization of nuclear power, most countries have taken interest in decontamination process of nuclear power plant and tried to develop a optimum process. Because open literature of the decontamination process are rare, it is hard to obtain skills on decontamination of foreign country and it is necessarily to develop proper chemical decontamination process system in Korea. In this study, applicable possibility in chemical decontamination for reactor coolant pump (RCP) was investigated for the various stainless steels. The stainless steel (STS) 304 showed the best electrochemical properties for corrosion resistance and the lowest weight loss ratio in chemical decontamination process with immersion type than other materials. However, the pitting corrosion was generated in both STS 415 and STS 431 with the increasing numbers of cycle. The intergranular corrosion in STS 431 was sporadically observed. The sizes of their pitting corrosion also increased with increasing cycle numbers

  18. A decontamination system for chemical weapons agents using a liquid solution on a solid sorbent

    Energy Technology Data Exchange (ETDEWEB)

    Waysbort, Daniel [Israel Institute for Biological Research, PO Box 19, Ness-Ziona 74100 (Israel); McGarvey, David J. [R and T Directorate, Edgewood Chemical and Biological Center (ECBC), Aberdeen Proving Ground-Edgewood Area, MD 21010 (United States)], E-mail: david.mcgarvey@us.army.mil; Creasy, William R.; Morrissey, Kevin M.; Hendrickson, David M. [SAIC, P.O. Box 68, Gunpowder Branch, Aberdeen Proving Ground, MD 21010 (United States); Durst, H. Dupont [R and T Directorate, Edgewood Chemical and Biological Center (ECBC), Aberdeen Proving Ground-Edgewood Area, MD 21010 (United States)

    2009-01-30

    A decontamination system for chemical warfare agents was developed and tested that combines a liquid decontamination reagent solution with solid sorbent particles. The components have fewer safety and environmental concerns than traditional chlorine bleach-based products or highly caustic solutions. The liquid solution, based on Decon Green{sup TM}, has hydrogen peroxide and a carbonate buffer as active ingredients. The best solid sorbents were found to be a copolymer of ethylene glycol dimethacrylate and n-lauryl methacrylate (Polytrap 6603 Adsorber); or an allyl methacrylate cross-linked polymer (Poly-Pore E200 Adsorber). These solids are human and environmentally friendly and are commonly used in cosmetics. The decontaminant system was tested for reactivity with pinacolyl methylphosphonofluoridate (Soman, GD), bis(2-chloroethyl)sulfide (Mustard, HD), and S-(2-diisopropylaminoethyl) O-ethyl methylphosphonothioate (VX) by using NMR Spectroscopy. Molybdate ion (MoO{sub 4}{sup -2}) was added to the decontaminant to catalyze the oxidation of HD. The molybdate ion provided a color change from pink to white when the oxidizing capacity of the system was exhausted. The decontaminant was effective for ratios of agent to decontaminant of up to 1:50 for VX (t{sub 1/2} {<=} 4 min), 1:10 for HD (t{sub 1/2} < 2 min with molybdate), and 1:10 for GD (t{sub 1/2} < 2 min). The vapor concentrations of GD above the dry sorbent and the sorbent with decontamination solution were measured to show that the sorbent decreased the vapor concentration of GD. The E200 sorbent had the additional advantage of absorbing aqueous decontamination solution without the addition of an organic co-solvent such as isopropanol, but the rate depended strongly on mixing for HD.

  19. A decontamination system for chemical weapons agents using a liquid solution on a solid sorbent

    International Nuclear Information System (INIS)

    Waysbort, Daniel; McGarvey, David J.; Creasy, William R.; Morrissey, Kevin M.; Hendrickson, David M.; Durst, H. Dupont

    2009-01-01

    A decontamination system for chemical warfare agents was developed and tested that combines a liquid decontamination reagent solution with solid sorbent particles. The components have fewer safety and environmental concerns than traditional chlorine bleach-based products or highly caustic solutions. The liquid solution, based on Decon Green TM , has hydrogen peroxide and a carbonate buffer as active ingredients. The best solid sorbents were found to be a copolymer of ethylene glycol dimethacrylate and n-lauryl methacrylate (Polytrap 6603 Adsorber); or an allyl methacrylate cross-linked polymer (Poly-Pore E200 Adsorber). These solids are human and environmentally friendly and are commonly used in cosmetics. The decontaminant system was tested for reactivity with pinacolyl methylphosphonofluoridate (Soman, GD), bis(2-chloroethyl)sulfide (Mustard, HD), and S-(2-diisopropylaminoethyl) O-ethyl methylphosphonothioate (VX) by using NMR Spectroscopy. Molybdate ion (MoO 4 -2 ) was added to the decontaminant to catalyze the oxidation of HD. The molybdate ion provided a color change from pink to white when the oxidizing capacity of the system was exhausted. The decontaminant was effective for ratios of agent to decontaminant of up to 1:50 for VX (t 1/2 ≤ 4 min), 1:10 for HD (t 1/2 1/2 < 2 min). The vapor concentrations of GD above the dry sorbent and the sorbent with decontamination solution were measured to show that the sorbent decreased the vapor concentration of GD. The E200 sorbent had the additional advantage of absorbing aqueous decontamination solution without the addition of an organic co-solvent such as isopropanol, but the rate depended strongly on mixing for HD

  20. How Clean is Safe? Improving the Effectiveness of Decontamination of Structures and People Following Chemical and Biological Incidents

    Energy Technology Data Exchange (ETDEWEB)

    Vogt (Sorensen), B.M.

    2003-04-03

    This report describes a U.S. Department of Energy, (DOE) Chemical and Biological National Security Program project that sought to establish what is known about decontamination of structures, objects, and people following an exposure to chemical or biological materials. Specifically we sought to identify the procedures and protocols used to determine when and how people or buildings are considered ''clean'' following decontamination. To fulfill this objective, the study systematically examined reported decontamination experiences to determine what procedures and protocols are currently employed for decontamination, the timeframe involved to initiate and complete the decontamination process, how the contaminants were identified, the factors determining when people were (or were not) decontaminated, the problems encountered during the decontamination process, how response efforts of agencies were coordinated, and the perceived social psychological effects on people who were decontaminated or who participated in the decontamination process. Findings and recommendations from the study are intended to aid decision-making and to improve the basis for determining appropriate decontamination protocols for recovery planners and policy makers for responding to chemical and biological events.

  1. Sorbents for effective removal of radioactive antimony during chemical decontamination

    International Nuclear Information System (INIS)

    Nishad, Padala Abdul; Bhaskarapillai, Anupkumar; Velmurugan, Sankaralingam

    2014-01-01

    Removal of radioactive antimony is a challenging problem. Often, during decontamination, they get mobilized around the system and redeposit in different areas thus offsetting the reduction in the radiation field obtained by removing other activities such as 60 Co. Thus, there is a clear need for better antimony removing materials/strategies for effective reactor decontamination. In this regard, six commercially available sorbents namely, Tulsion A33 (strong base anion (-OH) resin), Amberlite IRC-718 (chelating resin), Radex ® Sb-1000, nano TiO 2 -special grade (Inorganic type IX), Chitosan (biosorbent) and Aeroxide p25 (nano TiO 2 , Inorganic type IX) were evaluated for their antimony sorption properties. Radex ® and TiO 2 based materials were found to be more effective in removing both Sb(V) and Sb(III). Solution pH was seen to significantly influence the antimony sorption and the effect was more prominent in anion resin, when tested under column conditions. Apart from the commercial sorbents, we have synthesised a robust high performing sorbent (TA-Chitosan beads) in the form of stable beads, using nano-TiO 2 and chitosan. The beads were found to retain the antimony sorption properties of the nano-TiO 2 , while adapting a physical format suitable for large scale operations. The sorbent exhibited almost complete sorption of antimony both in low (ppb level) as well as high concentrations of antimony. The suitability of the beads for use in column mode has been established and its radiation stability was probed in detail. The beads were found to be stable to irradiations as ascertained from the TOC values and unchanged sorption properties. The sorption properties of the CHITA beads in typical decontamination formulation containing mixture of complexing agents have been investigated in detail. (author)

  2. Air Activated Self-Decontaminating Polydicyclopentadiene PolyHIPE Foams for Rapid Decontamination of Chemical Warfare Agents.

    Science.gov (United States)

    McGann, Christopher L; Daniels, Grant C; Giles, Spencer L; Balow, Robert B; Miranda-Zayas, Jorge L; Lundin, Jeffrey G; Wynne, James H

    2018-06-01

    The threat of chemical warfare agents (CWA) compels research into novel self-decontaminating materials (SDM) for the continued safety of first-responders, civilians, and active service personnel. The capacity to actively detoxify, as opposed to merely sequester, offending agents under typical environmental conditions defines the added value of SDMs in comparison to traditional adsorptive materials. Porous polymers, synthesized via the high internal phase emulsion (HIPE) templating, provide a facile fabrication method for materials with permeable open cellular structures that may serve in air filtration applications. PolyHIPEs comprising polydicyclopentadiene (polyDCPD) networks form stable hydroperoxide species following activation in air under ambient conditions. The hydroperoxide-containing polyDCPD materials react quickly with CWA simulants, Demeton-S and 2-chloroethyl ethyl sulfide, forming oxidation products as confirmed via gas chromatography mass spectrometry. The simplicity of the detoxification chemistry paired with the porous foam form factor presents an exciting opportunity for the development of self-decontaminating filter media. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Experience with dilute chemical decontamination in Indian Pressurized Heavy Water Reactors

    International Nuclear Information System (INIS)

    Velmurugan, S.; Rufus, A.L.; Sathyaseelan, V.S.; Subramanian, Veena; Mittal, V.K.; Narasimhan, S.V.

    2010-01-01

    Dilute Chemical Decontamination (DCD) process has been used in several full system and components of nuclear coolant systems to effectively remove the radioactive contaminants that causes radiation field and consequent MANREM problem. The DCD process uses chemicals in very low concentrations (millimolar) and dissolves the oxide film along with the activity incorporated in the oxide film. In DCD process operated under the regenerative mode, the chemical formulation spent in the process of oxide dissolution is replenished by passing through cation exchange columns. Finally, after achieving sufficient decontamination of the system/component, the added decontamination chemicals along with the activities and metal ions released during the process are removed by mixed bed ion exchange columns and the system is restored to normal operating condition in few days time. In PHWRs, the regenerative DCD process is applied for full primary coolant system decontamination. The chemicals are added directly to the heavy water coolant with the fuel in the core. In Indian PHWRs (MAPS-1 and 2, RAPS-1 and 2, NAPS-1 and 2 and KAPS-1), the process has been applied eleven times. A chemical formulation based on NTA, Citric acid and Ascorbic acid has been applied seven times with good results. Decontamination factors in the range 2-30 have been obtained in different components with good MANREM savings in the subsequent maintenance works. Efforts are on to modify the process to take care of the challenges posed by antimony isotope. An inhibitor (Rodine-92B) based process was successfully tested in NAPS-2 for removing antimony isotopes ( 122 Sb and 124 Sb). Further refining of the antimony removal process is being worked out. Similarly, the process is being modified to effectively remove the hotspot causing stellite particles in the moderator system of PHWRs. A permanganate based process has been developed and tested in several adjustor rod drive mechanisms in KAPS and NAPS. The experience of

  4. Restoration projects for decontamination of facilities from chemical, biological and radiological contamination after terrorist actions

    Energy Technology Data Exchange (ETDEWEB)

    Fingas, M.; Volchek, K.; Lumley, T.; Thouin, G.; Harrison, S.; Kuang, W. [Environment Canada, Ottawa, ON (Canada). Emergencies Science and Technology Division, Environmental Technology Centre, Science and Technology Branch; Payette, P.; Laframboise, D.; Best, M. [Public Health Agency of Canada, Ottawa, ON (Canada); Krishnan, J.; Wagener, S.; Bernard, K.; Majcher, M. [Public Health Agency of Canada, Winnipeg, MB (Canada); Cousins, T.; Jones, T. [Defence Research and Development Canada, Ottawa, ON (Canada); Velicogna, D.; Hornof, M.; Punt, M. [SAIC Canada, Ottawa, ON (Canada)

    2006-07-01

    This paper reviewed studies that identified better decontamination methods for chemical, biological and radiological/nuclear (CBRN) attacks. In particular, it reviewed aspects of 3 projects in which procedures were tested and validated for site restoration. Cleanup targets or standards for decontaminating buildings and materials after a CBRN attack were also developed. The projects were based on physicochemical and toxicological knowledge of potential terrorist agents and selected surface matrices. The projects also involved modeling and assessing environmental and health risks. The first multi-agent project involved gathering information on known procedures for restoration of areas including interiors and exteriors of buildings, contents, parking lots, lawn, and vehicles. Air inside the building was included. The efficacy of some of the proposed concepts was tested. Results included the determination of appropriate surrogates for anthrax and tests of liquid and gaseous biocides on the surrogates. The development of new contamination procedures using peroxyacetic acid were also discussed. The second project involved decontamination tests on CBRN using specially-constructed buildings at the Counter-terrorism Technology Centre at Defence Research and Development Canada in Suffield. The buildings will be contaminated with chemical and biological agents and with short-lived radionuclides. They will be decontaminated using the best-performing technologies known. Information collected will include fate of the contaminant and decontamination products, effectiveness of the restoration methods, cost and duration of cleanup and logistical problems. The third project is aimed at developing cleanup standards for decontaminating buildings and construction materials after a chemical or biological attack. It will create as many as 12 algorithms for the development of 50 standards which will help cleanup personnel and first-responders to gauge whether proposed methods can achieve

  5. Introduction of a cation in aqueous solution by electrolytic dissolution of metal. Applications to the decontamination of radioactive effluents

    International Nuclear Information System (INIS)

    Gauchon, Jean-Paul

    1979-01-01

    This research thesis aims at comparing results obtained in chemical decontamination of radioactive effluents with a metallic cation introduced by metal electro-dissolution or by dose addition. After an overview of methods used for the purification of radioactive effluents and a more precise presentation of chemical co-precipitation, the author reports preliminary tests of the application of chemical co-precipitation to the decontamination of radioactive effluents, reports the analysis of iron, zinc and copper behaviour in aqueous environment by means of thermodynamic diagrams and current-voltage curves. He reports the design and use of two electro-dissolution sets, and the application of copper electrolytic dissolution to the elimination of ruthenium in radioactive effluents. He finally addresses the purification treatment of effluents of nuclear reactors

  6. Development of the chemical decontamination process of uranium enrichment gas centrifuges

    International Nuclear Information System (INIS)

    Mita, Yutaka; Endo, Yuji; Yamanaka, Toshihiro; Oohashi, Yusuke

    2002-01-01

    In Ningyo-Toge Environmental Engineering Center, many of the centrifuges that were tested for uranium enrichment are kept in storage. In the future, it will be necessary to dispose of them properly. By categorizing these centrifuges as 'items that are not required to be treated as radioactive waste', chemical decontamination tests were conducted with the wet process (diluted sulfuric acid) to reduce the amount of such radioactive waste. As a result, concerning the rotors, the assumed radioactive level was attained as items that are not required to be treated as radioactive waste', but the effectiveness of the casings varied. As a future subject, in order to find the optimal decontamination process, the basic test shall be conducted continuously. By taking economical efficiency and the processing time into consideration, the decontamination process will be evaluated and a rational method examined. (author)

  7. A study of the decontamination procedures used for chemical analysis of polar deep ice cores

    Directory of Open Access Journals (Sweden)

    Takayuki Miyake

    2009-11-01

    Full Text Available We investigated the decontamination procedures used on polar deep ice cores before chemical analyses such as measurements of the concentrations of iron species and dust (microparticles. We optimized cutting and melting protocols for decontamination using chemically ultraclean polyethylene bags and simulated ice samples made from ultrapure water. For dust and ion species including acetate, which represented a high level of contamination, we were able to decrease contamination to below several μg l^ for ion concentrations and below 10000 particles ml^ for the dust concentration. These concentration levels of ion species and dust are assumed to be present in the Dome Fuji ice core during interglacial periods. Decontamination of the ice core was achieved by cutting away approximately 3 mm of the outside of a sample and by melting away approximately 30% of a sample's weight. Furthermore, we also report the preparation protocols for chemical analyses of the 2nd Dome Fuji ice core, including measurements of ion and dust concentrations, pH, electric conductivity (EC, and stable isotope ratios of water (δD and δO, based on the results of the investigation of the decontamination procedures.

  8. Chemical decontamination. I. Dephosphorylation of organophosphorus compounds; Decontamination chimique. I. Dephosphorylation des composes organophosphores

    Energy Technology Data Exchange (ETDEWEB)

    Segues, B.; Perez, E.; Rico-Lattes, I.; Riviere, M.; Lattes, A. [Toulouse-3 Univ., 31 (France)

    1996-12-31

    This work describes investigations of methods for the destruction of wastes containing toxic phosphorus esters due to the use of pesticides or chemical weapons. Compounds are destroyed by basic hydrolysis in various structured media (micellar catalysis) in the presence and absence of additives, in both water and mixed micellar media. Different methods are compared and evaluated 40 refs.

  9. THE CHEMICAL TECHNOLOGIES OF SOIL’S DECONTAMINATION

    Directory of Open Access Journals (Sweden)

    Roxana – Gabriela POPA

    2017-12-01

    Full Text Available The chemical soil degradation technologies are based on the pollutant conversion and immobilisation, or the mobilization, extraction and washing of pollutants. They use chemical agents that oxidize or reduce pollutants to less toxic or non-toxic forms and immobilize them in the underground environment in order to diminish their migration and the extent of pollution. Classification of chemical methods of depollution is based on the dominant reaction criterion: oxidation, reduction, neutralization, precipitation, chemical extraction, hydrolysis, dehalogenation, precipitation.

  10. Determination of trace amounts of chemical warfare agent degradation products in decontamination solutions with NMR spectroscopy.

    Science.gov (United States)

    Koskela, Harri; Rapinoja, Marja-Leena; Kuitunen, Marja-Leena; Vanninen, Paula

    2007-12-01

    Decontamination solutions are used for an efficient detoxification of chemical warfare agents (CWAs). As these solutions can be composed of strong alkaline chemicals with hydrolyzing and oxidizing properties, the analysis of CWA degradation products in trace levels from these solutions imposes a challenge for any analytical technique. Here, we present results of application of nuclear magnetic resonance spectroscopy for analysis of trace amounts of CWA degradation products in several untreated decontamination solutions. Degradation products of the nerve agents sarin, soman, and VX were selectively monitored with substantially reduced interference of background signals by 1D 1H-31P heteronuclear single quantum coherence (HSQC) spectrometry. The detection limit of the chemicals was at the low part-per-million level (2-10 microg/mL) in all studied solutions. In addition, the concentration of the degradation products was obtained with sufficient confidence with external standards.

  11. Decontamination issues for chemical and biological warfare agents: how clean is clean enough?

    Science.gov (United States)

    Raber, E; Jin, A; Noonan, K; McGuire, R; Kirvel, R D

    2001-06-01

    The objective of this assessment is to determine what level of cleanup will be required to meet regulatory and stakeholder needs in the case of a chemical and/or biological incident at a civilian facility. A literature review for selected, potential chemical and biological warfare agents shows that dose information is often lacking or controversial. Environmental regulatory limits or other industrial health guidelines that could be used to help establish cleanup concentration levels for such agents are generally unavailable or not applicable for a public setting. Although dose information, cleanup criteria, and decontamination protocols all present challenges to effective planning, several decontamination approaches are available. Such approaches should be combined with risk-informed decision making to establish reasonable cleanup goals for protecting health, property, and resources. Key issues during a risk assessment are to determine exactly what constitutes a safety hazard and whether decontamination is necessary or not for a particular scenario. An important conclusion is that cleanup criteria are site dependent and stakeholder specific. The results of a modeling exercise for two outdoor scenarios are presented to reinforce this conclusion. Public perception of risk to health, public acceptance of recommendations based on scientific criteria, political support, time constraints, and economic concerns must all be addressed in the context of a specific scenario to yield effective and acceptable decontamination.

  12. Recent Advances in Decontamination of Chemical Warfare Agents

    OpenAIRE

    Abdul Wadood Khan; Sabna Kotta; Shahid Husain Ansari; Javed Ali; Rakesh Kumar Sharma

    2013-01-01

    The recent turmoil and volatile situation in many countries and the increased risk of terrorist activities have raised alarm bells for the field of defense against toxic chemical/materials. These situations poses threats to society as terrorists can take advantage of such situations to strike and cause public mayhem. A number of chemicals have the potential of being used as chemical warfare (CW) agents. CW agents could immediately kill or incapacitate the affected individuals even when they a...

  13. Modeling the transport of chemical warfare agents and simulants in polymeric substrates for reactive decontamination

    Science.gov (United States)

    Pearl, Thomas; Mantooth, Brent; Varady, Mark; Willis, Matthew

    2014-03-01

    Chemical warfare agent simulants are often used for environmental testing in place of highly toxic agents. This work sets the foundation for modeling decontamination of absorbing polymeric materials with the focus on determining relationships between agents and simulants. The correlations of agents to simulants must consider the three way interactions in the chemical-material-decontaminant system where transport and reaction occur in polymer materials. To this end, diffusion modeling of the subsurface transport of simulants and live chemical warfare agents was conducted for various polymer systems (e.g., paint coatings) with and without reaction pathways with applied decontamination. The models utilized 1D and 2D finite difference diffusion and reaction models to simulate absorption and reaction in the polymers, and subsequent flux of the chemicals out of the polymers. Experimental data including vapor flux measurements and dynamic contact angle measurements were used to determine model input parameters. Through modeling, an understanding of the relationship of simulant to live chemical warfare agent was established, focusing on vapor emission of agents and simulants from materials.

  14. Corrosion surveillance of the chemical decontamination process in Kuosheng nuclear power plant

    International Nuclear Information System (INIS)

    Wang, L.H.

    2002-01-01

    The Piping Recirculation System (RRS) and reactor water clean-up system (RWCU) of Kuosheng Nuclear Power Plant of Taiwan Power Company were decontaminated by CORD process of Framatome ANP GmbH during the outage at October 2001. This is the first time that CORD process was adopted and applied in Taiwan Nuclear Power Plant. To verify minor corrosion damage and correct process control, the material corrosion condition was monitored during all the stages of the chemical decontamination work. Three kinds of specimen were adopted in this corrosion monitoring, including corrosion coupons for weight loss measurements, electrochemical specimens for on-line corrosion monitoring, and WOL specimens (wedge opening loaded) for stress corrosion evaluation. The measured metal losses from nine coupon materials did not reveal any unexpected or intolerable high corrosion damage from the CORD UV or CORD CS processes. The coupon materials included type 304 stainless steel (SS) with sensitized and as-received thermal history, type 308 weld filler, type CF8 cast SS, nickel base alloy 182 weld filler, Inconel 600, Stellite 6 hard facing alloy, NOREM low cobalt hard facing alloy, and A106B carbon steel (CS). The electrochemical noise (ECN) measurements from three-electrode electrochemical probe precisely depicted the metal corrosion variation with the decontamination process change. Most interestingly, the estimated trend of accumulated metal loss is perfectly corresponding to the total removed activities. The ECN measurements were also used for examining the effect of different SS oxide films pre-formed in NWC and HWC on the decontamination efficiency, and for evaluating the galvanic effect of CS with SS. The existing cracks did not propagate further during the decontamination. The average decontamination factors achieved were 50.8 and 4.2 respectively for RRS and RWCU. (authors)

  15. Chemical Decontamination of Campylobacter jejuni on Chicken Skin and Meat

    DEFF Research Database (Denmark)

    Riedel, Charlotte Tandrup; Brøndsted, Lone; Rosenquist, Hanne

    2009-01-01

    This study evaluated the effectiveness of 11 chemical compounds to reduce Campylobacter jejuni on chicken skin and meat samples dipped in chemical solutions. Treatment of skin samples for 1 min using tartaric acid (2%) and caprylic acid sodium salt (5%) caused reductions of C. jejuni NCTC11168...... effective, indicating that some cells may recover after a 1-min treatment with these chemicals. An increase in treatment time to 15 min resulted in higher effectiveness of trisodium phosphate and formic acid. Interestingly, when reduction of the C. jejuni population was compared on chicken skin and meat...

  16. Autonomous bio-chemical decontaminator (ABCD) against weapons of mass destruction

    Science.gov (United States)

    Hyacinthe, Berg P.

    2006-05-01

    The proliferation of weapons of mass destruction (WMD) and the use of such elements pose an eminent asymmetric threat with disastrous consequences to the national security of any nation. In particular, the use of biochemical warfare agents against civilians and unprotected troops in international conflicts or by terrorists against civilians is considered as a very peculiar threat. Accordingly, taking a quarantine-before-inhalation approach to biochemical warfare, the author introduces the notion of autonomous biochemical decontamination against WMD. In the unfortunate event of a biochemical attack, the apparatus proposed herein is intended to automatically detect, identify, and more importantly neutralize a biochemical threat. Along with warnings concerning a cyber-WMD nexus, various sections cover discussions on human senses and computer sensors, corroborating evidence related to detection and neutralization of chemical toxins, and cyber-assisted olfaction in stand alone, peer-to-peer, and network settings. In essence, the apparatus can be used in aviation and mass transit security to initiate mass decontamination by dispersing a decontaminant aerosol or to protect the public water supply against a potential bioterrorist attack. Future effort may involve a system-on-chip (SoC) embodiment of this apparatus that allows a safer environment for the emerging phenomenon of cyber-assisted olfaction and morph cell phones into ubiquitous sensors/decontaminators. Although this paper covers mechanisms and protocols to avail a neutralizing substance, further research will need to explore the substance's various pharmacological profiles and potential side effects.

  17. Decontamination of Chemical/Biological Warfare (CBW) Agents Using an Atmospheric Pressure Plasma Jet (APPJ)

    Science.gov (United States)

    Herrmann, Hans W.

    1998-11-01

    The atmospheric pressure plasma jet (APPJ) is a non-thermal, high pressure, uniform glow discharge that produces a high velocity effluent stream of highly reactive chemical species. The discharge operates on a feedstock gas (e.g. He/O_2/H_2O) which flows between an outer, grounded, cylindrical electrode and an inner, coaxial electrode powered at 13.56 MHz RF. While passing through the plasma, the feedgas becomes excited, dissociated or ionized by electron impact. Once the gas exits the discharge volume, ions and electrons are rapidly lost by recombination, but the fast-flowing effluent still contains metastables (e.g. O2*, He*) and radicals (e.g. O, OH). These reactive species have been shown to be effective neutralizers of surrogates for anthrax spores, mustard blister agent and VX nerve gas. Unlike conventional, wet decontamination methods, the plasma effluent does not cause corrosion of most surfaces and does not damage wiring, electronics, nor most plastics. This makes it highly suitable for decontamination of high value sensitive equipment such as is found in vehicle interiors (i.e. tanks, planes...) for which there is currently no good decontamination technique. Furthermore, the reactive species rapidly degrade into harmless products leaving no lingering residue or harmful byproducts. Physics of the APPJ will be discussed and results of surface decontamination experiments using simulant and actual CBW agents will be presented.

  18. Processes of elimination of activated corrosion products. Chemical decontamination - fuel cleaning

    International Nuclear Information System (INIS)

    Viala, C.; Brun, C.; Neuhaus, R.; Richier, S.; Bachet, M.

    2007-01-01

    The abatement of the individual and collective dose of a PWR imposes to control the source term through different processes implemented during the plant exploitation. When the limits of these different optimization processes are reached, the abatement of dose rates requires the implementation of curative processes. The objective is thus to eliminate the contaminated oxides and deposits present on surfaces free of radiation flux, and eventually on surfaces under radiation flux and on the fuel itself. The chemical decontamination of equipments and systems is the main and universal remedy implemented at different levels. On the other hand, the ultrasonic cleaning of fuel assemblies is a promising process. This paper aims at illustrating these different techniques using concrete examples of application in France and abroad (decontamination during steam generator replacement, decontamination of primary pump scroll in hot workshop, decontamination of loop sections, ultrasonic cleaning of fuel). The description of these different operations stresses on their efficiency in terms of dosimetric gain, duration of implementation, generation of wastes, and recontamination following their implementation. (J.S.)

  19. Treatability Studies Used to Test for Exothermic Reactions of Plutonium Decontamination Chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Ewalt, John R.; Minette, Michael J.; Hopkins, Andrea M.; Cooper, Thurman D.; Simiele, Connie J.; Scott, Paul A.; Scheele, Randall D.; Charboneau, Stacy L.

    2005-08-07

    Fluor Hanford is decommissioning the PFP at the Hanford Site and is considering using agressive chemicals to remove transuranium contaminants. As part of the evaluation of these methods, Fluor is considering the path for disposal and the thermal stability of the waste products from the decontamination process. This paper provides the results of our studies on cerium nitrate and RadPro(TM), a nitric acid based complexant.

  20. Optimization of Nonambulant Mass Casualty Decontamination Protocols as Part of an Initial or Specialist Operational Response to Chemical Incidents.

    Science.gov (United States)

    Chilcott, Robert P; Mitchell, Hannah; Matar, Hazem

    2018-05-30

    The UK's Initial Operational Response (IOR) is a new process for improving the survival of multiple casualties following a chemical, biological, radiological or nuclear incident. Whilst the introduction of IOR represents a patient-focused response for ambulant casualties, there is currently no provision for disrobe and dry decontamination of nonambulant casualties. Moreover, the current specialist operational response (SOR) protocol for nonambulant casualty decontamination (also referred to as "clinical decontamination") has not been subject to rigorous evaluation or development. Therefore, the aim of this study was to confirm the effectiveness of putatively optimized dry (IOR) and wet (SOR) protocols for nonambulant decontamination in human volunteers. Dry and wet decontamination protocols were objectively evaluated using human volunteers. Decontamination effectiveness was quantified by liquid chromatography-mass spectrometry analysis of the recovery of a chemical warfare agent simulant (methylsalicylate) from skin and hair of volunteers, with whole-body fluorescence imaging to quantify the skin distribution of residual simulant. Both the dry and wet decontamination processes were rapid (3 and 4 min, respectively) and were effective in removing simulant from the hair and skin of volunteers, with no observable adverse effects related to skin surface spreading of contaminant. Further studies are required to assess the combined effectiveness of dry and wet decontamination under more realistic conditions and to develop appropriate operational procedures that ensure the safety of first responders.

  1. Decontamination in preparation for dismantlement - AREVA's chemical decontamination technologies, projects performed and results obtained in the period 2011-2016

    International Nuclear Information System (INIS)

    Topf, C.; Sempere Belda, L.

    2017-01-01

    As a consequence of the nuclear phase-out decreed by the German government, several nuclear power plants in the country have already ceased operation. The remaining ones will cease operation by 2022. This has turned Germany into one of the most active regions worldwide in the field of nuclear decommissioning, with new and emerging technologies being deployed on the field, and already preexisting technologies being put to the test, optimized and developed into full maturity. The chemistry services division of AREVA GmbH has already performed 5 Full System Decontaminations (FSD) in preparation for decommissioning in this period - three in PWRs and two in BWRs - along with other international projects of relevance for decommissioning operations. During a FSD, the complete primary circuit of a nuclear power plant including auxiliary systems is subject to a chemical treatment; designed to remove radioactive matter accumulated onto system surfaces during operation. Through the effective removal of this radioactive accumulations contact dose rates on the different components of the primary circuit can be consistently reduced by factors larger than 50. This results in much lower ambient dose rates and, hence, in very significant dose savings for subsequent decommissioning activities. Additionally, dismantlement operations of large components are considerably simplified and can be performed under conditions that wouldn't have been possible before. The project specific objectives and challenges, the technologies employed, and the results obtained are presented and commented here. (authors)

  2. Oxidative decontamination of chemical and biological warfare agents using L-Gel.

    Science.gov (United States)

    Raber, Ellen; McGuire, Raymond

    2002-08-05

    A decontamination method has been developed using a single reagent that is effective both against chemical warfare (CW) and biological warfare (BW) agents. The new reagent, "L-Gel", consists of an aqueous solution of a mild commercial oxidizer, Oxone, together with a commercial fumed silica gelling agent, Cab-O-Sil EH-5. L-Gel is non-toxic, environmentally friendly, relatively non-corrosive, maximizes contact time because of its thixotropic nature, clings to walls and ceilings, and does not harm carpets or painted surfaces. The new reagent also addresses the most demanding requirements for decontamination in the civilian sector, including availability, low maintenance, ease of application and deployment by a variety of dispersal mechanisms, minimal training and acceptable expense. Experiments to test the effectiveness of L-Gel were conducted at Lawrence Livermore National Laboratory and independently at four other locations. L-Gel was tested against all classes of chemical warfare agents and against various biological warfare agent surrogates, including spore-forming bacteria and non-virulent strains of real biological agents. Testing showed that L-Gel is as effective against chemical agents and biological materials, including spores, as the best military decontaminants.

  3. Application of the chemical properties of ruthenium to decontamination processes

    International Nuclear Information System (INIS)

    Fontaine, A.; Berger, D.

    1965-01-01

    The chemical properties of ruthenium in the form of an aqueous solution of the nitrate and of organic tributylphosphate solution are reviewed. From this data, some known examples are given: they demonstrate the processes of separation or of elimination of ruthenium from radioactive waste. (authors) [fr

  4. Researchers study decontamination of chemical, biological warfare agents

    OpenAIRE

    Trulove, Susan

    2007-01-01

    The U.S. Army Research Office has awarded Virginia Tech a $680,000 grant over two years to build an instrument that can be used to study the chemistry of gases that will decompose both chemical and biological warfare agents on surfaces.

  5. Chemical analysis of bleach and hydroxide-based solutions after decontamination of the chemical warfare agent O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate (VX).

    Science.gov (United States)

    Hopkins, F B; Gravett, M R; Self, A J; Wang, M; Chua, Hoe-Chee; Hoe-Chee, C; Lee, H S Nancy; Sim, N Lee Hoi; Jones, J T A; Timperley, C M; Riches, J R

    2014-08-01

    Detailed chemical analysis of solutions used to decontaminate chemical warfare agents can be used to support verification and forensic attribution. Decontamination solutions are amongst the most difficult matrices for chemical analysis because of their corrosive and potentially emulsion-based nature. Consequently, there are relatively few publications that report their detailed chemical analysis. This paper describes the application of modern analytical techniques to the analysis of decontamination solutions following decontamination of the chemical warfare agent O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate (VX). We confirm the formation of N,N-diisopropylformamide and N,N-diisopropylamine following decontamination of VX with hypochlorite-based solution, whereas they were not detected in extracts of hydroxide-based decontamination solutions by nuclear magnetic resonance (NMR) spectroscopy or gas chromatography-mass spectrometry. We report the electron ionisation and chemical ionisation mass spectroscopic details, retention indices, and NMR spectra of N,N-diisopropylformamide and N,N-diisopropylamine, as well as analytical methods suitable for their analysis and identification in solvent extracts and decontamination residues.

  6. Effect of gamma irradiation on microbial decontamination, and chemical and sensory characteristic of lycium fruit

    Energy Technology Data Exchange (ETDEWEB)

    Wen, H.-W. [Department of Food Science and Technology, Cornell University, Geneva, NY 14456 (United States); Chung, H.-P. [Nuclear Science and Technology Development Center, National Tsing Hua University, Hsinchu, Taiwan (China); Chou, F.-I. [Nuclear Science and Technology Development Center, National Tsing Hua University, Hsinchu, Taiwan (China)]. E-mail: fichou@mx.nthu.edu.tw; Lin, I-H. [Committee on Chinese Medicine and Pharmacy, Department of Health, Executive Yuan, Taiwan (China); Hsieh, P.-C. [Committee on Chinese Medicine and Pharmacy, Department of Health, Executive Yuan, Taiwan (China)

    2006-05-15

    Lycium fruit, popular traditional Chinese medicine and food supplement generally is ingested uncooked, was exposed to several doses of gamma irradiation (0-14 kGy) to evaluate decontamination efficiency, changes in chemical composition, and changes in sensory characteristic. In this study, lycium fruit specimens contained microbial counts of 3.1x10{sup 3}-1.7x10{sup 5} CFU/g and 14 kGy was sufficient for microbial decontamination. Before irradiation, the main microbe isolated from lycium fruit was identified as a strain of yeast, Cryptococcus laurentii. After 10 kGy of irradiation, a Gram-positive spore-forming bacterium, Bacillus cereus, was the only survivor. The first 90% reduction (LD{sub 9}) of C. laurentii and B. cereus was approximately 0.6 and 6.5 kGy, respectively, the D{sub 1} doses of C. laurentii and B. cereus was approximately 0.6 and 1.7 kGy, respectively. After 14 kGy irradiation, except the vitamin C content, other chemical composition (e.g., crude protein, {beta}-carotene, riboflavin, fructose, etc.) and the sensory characteristic of lycium fruit specimens did not have significant changes. In conclusion, 14 kGy is the optimal decontamination dose for lycium fruit for retention of its sensory quality and extension of shelf life.

  7. Effect of gamma irradiation on microbial decontamination, and chemical and sensory characteristic of lycium fruit

    International Nuclear Information System (INIS)

    Wen, H.-W.; Chung, H.-P.; Chou, F.-I.; Lin, I-H.; Hsieh, P.-C.

    2006-01-01

    Lycium fruit, popular traditional Chinese medicine and food supplement generally is ingested uncooked, was exposed to several doses of gamma irradiation (0-14 kGy) to evaluate decontamination efficiency, changes in chemical composition, and changes in sensory characteristic. In this study, lycium fruit specimens contained microbial counts of 3.1x10 3 -1.7x10 5 CFU/g and 14 kGy was sufficient for microbial decontamination. Before irradiation, the main microbe isolated from lycium fruit was identified as a strain of yeast, Cryptococcus laurentii. After 10 kGy of irradiation, a Gram-positive spore-forming bacterium, Bacillus cereus, was the only survivor. The first 90% reduction (LD 9 ) of C. laurentii and B. cereus was approximately 0.6 and 6.5 kGy, respectively, the D 1 doses of C. laurentii and B. cereus was approximately 0.6 and 1.7 kGy, respectively. After 14 kGy irradiation, except the vitamin C content, other chemical composition (e.g., crude protein, β-carotene, riboflavin, fructose, etc.) and the sensory characteristic of lycium fruit specimens did not have significant changes. In conclusion, 14 kGy is the optimal decontamination dose for lycium fruit for retention of its sensory quality and extension of shelf life

  8. National demonstration of full reactor coolant system (RCS) chemical decontamination at Indian Point 2

    Energy Technology Data Exchange (ETDEWEB)

    Trovato, S.A.; Parry, J.O. [Consolidated Edison Co., New York, NY (United States)

    1995-03-01

    Key to the safe and efficient operation of the nation`s civilian nuclear power plants is the performance of maintenance activities within regulations and guidelines for personnel radiation exposure. However, maintenance activities, often performed in areas of relatively high radiation fields, will increase as the nation`s plant age. With the Nuclear Regulatory Commission (NRC) lowering the allowable radiation exposure to plant workers in 1994 and considering further reductions and regulations in the future, it is imperative that new techniques be developed and applied to reduce personnel exposure. Full primary system chemical decontamination technology offers the potential to be single most effective method of maintaining workers exposure {open_quotes}as low as reasonably achievable{close_quotes} (ALARA) while greatly reducing plant operation and maintenance (O&M) costs. A three-phase program underway since 1987, has as its goal to demonstrate that full RCS decontamination is a visible technology to reduce general plant radiation levels without threatening the long term reliability and operability of a plant. This paper discusses research leading to and plans for a National Demonstration of Full RCS Chemical Decontamination at Indian Point 2 nuclear generating station in 1995.

  9. Research on a pellet co-precipitation micro-filtration process for the treatment of liquid waste containing strontium

    International Nuclear Information System (INIS)

    Xin Luo; North China Institute of Science and Technology, Beijing; Guanghui Zhang; Xue Wang; Ping Gu

    2013-01-01

    The chemical precipitation method for radioactive wastewater treatment has the advantages of being simple and cost-effective. However, difficulties with the solid–liquid separation and sludge concentration restrict the application of this method. In this paper, a pellet co-precipitation micro-filtration (PCM) process was studied for treating strontium-containing wastewater on a laboratory scale. The seed was prepared by CaCO 3 powders. Sr 2+ and CO 3 2- were constantly crystallised on the seed surface, with Na 2 CO 3 as the precipitating agent in the pellet reactor. The following membrane separator with the addition of FeCl 3 enhanced the treatment effect. The average strontium concentrations in the raw water and in the effluent were 12.0 and 0.0220 mg/L, respectively. The strontium decontamination factor (DF) increased with the operation time, with an average value of 577. The precipitate particles formed gradually grew larger, with good sedimentation properties. When the experiment was complete, the formed precipitate was separated easily from the liquid phase and directly discharged. The concentration factor (CF) was 1,958. In the PCM process, crystallisation was the main mechanism for strontium removal, with the influent strontium level playing an important role. Membrane pore blockage and cake layer formation could help to further intercept the strontium crystallites. Furthermore, ferric chloride coagulation in the membrane separator also contributed to strontium removal. The PCM process has potential for wider application in the removal of strontium from wastewater. (author)

  10. Assessment of chemical processes for the post-accident decontamination of reactor-coolant systems. Final report

    International Nuclear Information System (INIS)

    Munson, L.F.; Card, C.J.; Divine, J.R.

    1983-02-01

    Previously used chemical decontamination processes and potentially useful new decontamination processes were examined for the usefulness following a reactor accident. Both generic fuel damage accidents and the accident at TMI-2 were considered. A total of fourteen processes were evaluated. Process evaluation included data in the following categories: technical description of the process, recorded past usage, effectiveness, process limitation, safety consideration, and waste management. These data were evaluated, and cost considerations were presented along with a description of the applicability of the process to TMI-2 and development and demonstration needs. Specific recommendations regarding a primary-system decontamination development program to support TMI-2 recovery were also presented

  11. Role of alkyl alcohol on viscosity of silica-based chemical gels for decontamination of highly radioactive nuclear facilities

    International Nuclear Information System (INIS)

    Choi, B. S.; Yoon, S. B.; Jung, C. H.; Lee, K. W.; Moon, J. K.

    2012-01-01

    Silica-based chemical gel for the decontamination of nuclear facilities was prepared by using fumed silica as a viscosifier, a 0.5 M Ce (IV) solution dissolved in concentrated nitric acid as a chemical decontamination agent, and tripropylene glycol butyl ether (TPGBE) as a co-viscosifier. A new effective strategy for the preparation of the chemical gel was investigated by introducing the alkyl alcohols as organic solvents to effectively dissolve the co-viscosifier. The mixture solution of the co-viscosifier and alkyl alcohols was more effective in the control of viscosity than that of the co-viscosifier only in gel. Here, the alkyl alcohols played a key role as an effective dissolution solvent for the co-viscosifier in the preparation of the chemical gel, resulting in a reducing of the amount of the co-viscosifier and gel time compared with that of the chemical gel prepared without the alkyl alcohols. It was considered that the alkyl alcohols contributed to the effective dissolution of the co-viscosifier as well as the homogeneous mixing in the formation of the gel, while the co-viscosifier in an aqueous media of the chemical decontamination agent solution showed a lower solubility. The decontamination efficiency of the chemical gels prepared in this work using a multi-channel analyzer (MCA) showed a high decontamination efficiency of over ca. 94% and ca. 92% for Co-60 and Cs-137 contaminated on surface of the stainless steel 304, respectively. (authors)

  12. Iron-montmorillonite clays as active sorbents for the decontamination of hazardous chemical warfare agents.

    Science.gov (United States)

    Carniato, F; Bisio, C; Evangelisti, C; Psaro, R; Dal Santo, V; Costenaro, D; Marchese, L; Guidotti, M

    2018-02-27

    A class of heterogeneous catalysts based on commercial bentonite from natural origin, containing at least 80 wt% of montmorillonite clay, was designed to transform selectively and under mild conditions toxic organosulfur and organophosphorus chemical warfare agents into non-noxious products with a reduced impact on health and environment. The bentonite from the natural origin was modified by introducing iron species and acid sites in the interlayer space, aiming to obtain a sorbent with strong catalytic oxidising and hydrolytic properties. The catalytic performance of these materials was evaluated in the oxidative abatement of (2-chloroethyl)ethyl sulfide (CEES), a simulant of sulfur mustard, in the presence of aqueous hydrogen peroxide as an oxidant. A new decontamination formulation was, moreover, proposed and obtained by mixing sodium perborate, as a solid oxidant, to iron-bentonite catalysts. Solid-phase decontamination tests, performed on a cotton textile support contaminated with organosulfide and organophosphonate simulant agents revealed the good activity of the solid formulation, especially in the in situ detoxification of blistering agents. Tests carried out on the real blistering warfare agent, sulfur mustard (HD agent), showed that, thanks to the co-presence of the iron-based clay together with the solid oxidant component, a good decontamination of the test surface from the real warfare agent could be achieved (80% contaminant degradation, under ambient conditions, in 24 h).

  13. Analysis on the Current Status of Chemical Decontamination Technology of Steam Generators in the Oversea Nuclear Power Plants (NPPs)

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Taebin; Kim, Sukhoon; Kim, Juyoul; Kim, Juyub; Lee, Seunghee [FNC Technology Co. Ltd., Yongin (Korea, Republic of)

    2015-10-15

    The steam generators in Hanbit Unit 3 and 4 are scheduled to be replaced in 2018 and 2019, respectively. Nevertheless, the wastes from the dismantled steam generators are currently just on-site stored in the NPP because there are no disposal measures for the waste and lack of the decontamination techniques for large-sized metallic equipment. In contrast, in the oversea NPPs, there are many practical cases of chemical decontamination not only for oversized components in the NPPs such as reactor pressure vessel and steam generator, but also for major pipes. Chemical decontamination technique is more effective in decontaminating the components with complicated shape compared with mechanical one. Moreover, a high decontamination factor can be obtained by using strong solvent, and thereby most of radionuclides can be removed. Due to these advantages, the chemical decontamination has been used most frequently for operation of decontaminating the large-sized equipment. In this study, an analysis on the current status of chemical decontamination technique used for the steam generators of the foreign commercial NPPs was performed. In this study, the three major chemical decontamination processes were reviewed, which are applied to the decommissioning process of the steam generators in the commercial NPPs of the United States, Germany, and Belgium. The three processes have the different features in aspect of solvent, while those are based in common on the oxidation and reduction between the target metal surface and solvents. In addition, they have the same goals for improving the decontamination efficiency and decreasing the amount of the secondary waste generation. Based on the analysis results on component sub-processes and major advantages and disadvantages of each process, Table 2 shows the key fundamental technologies for decontamination of the steam generator in Korea and the major considerations in the development process of each technology. It is necessary to prepare

  14. Vesicants and nerve agents in chemical warfare. Decontamination and treatment strategies for a changed world.

    Science.gov (United States)

    Devereaux, Asha; Amundson, Dennis E; Parrish, J S; Lazarus, Angeline A

    2002-10-01

    Vesicants and nerve agents have been used in chemical warfare for ages. They remain a threat in today's altered political climate because they are relatively simple to produce, transport, and deploy. Vesicants, such as mustard and lewisite, can affect the skin, eyes, respiratory system, and gastrointestinal system. They leave affected persons at risk for long-term effects. Nerve agents, such as tabun, sarin, soman, and VX, hyperstimulate the muscarinic and nicotinic receptors of the nervous system. Physicians need to familiarize themselves with the clinical findings of such exposures and the decontamination and treatment strategies necessary to minimize injuries and deaths.

  15. Supercritical antisolvent co-precipitation of rifampicin and ethyl cellulose.

    Science.gov (United States)

    Djerafi, Rania; Swanepoel, Andri; Crampon, Christelle; Kalombo, Lonji; Labuschagne, Philip; Badens, Elisabeth; Masmoudi, Yasmine

    2017-05-01

    Rifampicin-loaded submicron-sized particles were prepared through supercritical anti-solvent process using ethyl cellulose as polymeric encapsulating excipient. Ethyl acetate and a mixture of ethyl acetate/dimethyl sulfoxide (70/30 and 85/15) were used as solvents for both drug and polymeric excipient. When ethyl acetate was used, rifampicin was crystallized separately without being embedded within the ethyl cellulose matrix while by using the ethyl acetate/dimethyl sulfoxide mixture, reduced crystallinity of the active ingredient was observed and a simultaneous precipitation of ethyl cellulose and drug was achieved. The effect of solvent/CO 2 molar ratio and polymer/drug mass ratio on the co-precipitates morphology and drug loading was investigated. Using the solvent mixture, co-precipitates with particle sizes ranging between 190 and 230nm were obtained with drug loading and drug precipitation yield from respectively 8.5 to 38.5 and 42.4 to 77.2% when decreasing the ethyl cellulose/rifampicin ratio. Results show that the solvent nature and the initial drug concentrations affect morphology and drug precipitation yield of the formulations. In vitro dissolution studies revealed that the release profile of rifampicin was sustained when co-precipitation was carried out with the solvent mixture. It was demonstrated that the drug to polymer ratio influenced amorphous content of the SAS co-precipitates. Differential scanning calorimetry thermograms and infrared spectra revealed that there is neither interaction between rifampicin and the polymer nor degradation of rifampicin during co-precipitation. In addition, stability stress tests on SAS co-precipitates were carried out at 75% relative humidity and room temperature in order to evaluate their physical stability. SAS co-precipitates were X-ray amorphous and remained stable after 6months of storage. The SAS co-precipitation process using a mixture of ethyl acetate/dimethyl sulfoxide demonstrates that this strategy can

  16. Development of haemostatic decontaminants for treatment of wounds contaminated with chemical warfare agents. 3: Evaluation of in vitro topical decontamination efficacy using damaged skin.

    Science.gov (United States)

    Lydon, Helen L; Hall, Charlotte A; Dalton, Christopher H; Chipman, J Kevin; Graham, John S; Chilcott, Robert P

    2017-08-01

    Previous studies have demonstrated that haemostatic products with an absorptive mechanism of action retain their clotting efficiency in the presence of toxic materials and are effective in decontaminating chemical warfare (CW) agents when applied to normal, intact skin. The purpose of this in vitro study was to assess three candidate haemostatic products for effectiveness in the decontamination of superficially damaged porcine skin exposed to the radiolabelled CW agents, soman (GD), VX and sulphur mustard (HD). Controlled physical damage (removal of the upper 100 μm skin layer) resulted in a significant enhancement of the dermal absorption of all three CW agents. Of the haemostatic products assessed, WoundStat™ was consistently the most effective, being equivalent in performance to a standard military decontaminant (fuller's earth). These data suggest that judicious application of haemostatic products to wounds contaminated with CW agents may be a viable option for the clinical management of casualties presenting with contaminated, haemorrhaging injuries. Further studies using a relevant animal model are required to confirm the potential clinical efficacy of WoundStat™ for treating wounds contaminated with CW agents. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  17. Decontamination of chemical and biological warfare (CBW) agents using an atmospheric pressure plasma jet (APPJ)

    International Nuclear Information System (INIS)

    Herrmann, H.W.; Henins, I.; Park, J.; Selwyn, G.S.

    1999-01-01

    The atmospheric pressure plasma jet (APPJ) [A. Schuetze et al., IEEE Trans. Plasma Sci. 26, 1685 (1998)] is a nonthermal, high pressure, uniform glow plasma discharge that produces a high velocity effluent stream of highly reactive chemical species. The discharge operates on a feedstock gas (e.g., He/O 2 /H 2 O), which flows between an outer, grounded, cylindrical electrode and an inner, coaxial electrode powered at 13.56 MHz rf. While passing through the plasma, the feedgas becomes excited, dissociated or ionized by electron impact. Once the gas exits the discharge volume, ions and electrons are rapidly lost by recombination, but the fast-flowing effluent still contains neutral metastable species (e.g., O 2 * , He * ) and radicals (e.g., O, OH). This reactive effluent has been shown to be an effective neutralizer of surrogates for anthrax spores and mustard blister agent. Unlike conventional wet decontamination methods, the plasma effluent does not cause corrosion and it does not destroy wiring, electronics, or most plastics, making it highly suitable for decontamination of sensitive equipment and interior spaces. Furthermore, the reactive species in the effluent rapidly degrade into harmless products leaving no lingering residue or harmful by-products. copyright 1999 American Institute of Physics

  18. Decontamination of chemical and biological warfare (CBW) agents using an atmospheric pressure plasma jet (APPJ)

    Science.gov (United States)

    Herrmann, H. W.; Henins, I.; Park, J.; Selwyn, G. S.

    1999-05-01

    The atmospheric pressure plasma jet (APPJ) [A. Schütze et al., IEEE Trans. Plasma Sci. 26, 1685 (1998)] is a nonthermal, high pressure, uniform glow plasma discharge that produces a high velocity effluent stream of highly reactive chemical species. The discharge operates on a feedstock gas (e.g., He/O2/H2O), which flows between an outer, grounded, cylindrical electrode and an inner, coaxial electrode powered at 13.56 MHz rf. While passing through the plasma, the feedgas becomes excited, dissociated or ionized by electron impact. Once the gas exits the discharge volume, ions and electrons are rapidly lost by recombination, but the fast-flowing effluent still contains neutral metastable species (e.g., O2*, He*) and radicals (e.g., O, OH). This reactive effluent has been shown to be an effective neutralizer of surrogates for anthrax spores and mustard blister agent. Unlike conventional wet decontamination methods, the plasma effluent does not cause corrosion and it does not destroy wiring, electronics, or most plastics, making it highly suitable for decontamination of sensitive equipment and interior spaces. Furthermore, the reactive species in the effluent rapidly degrade into harmless products leaving no lingering residue or harmful by-products.

  19. Supercritical antisolvent co-precipitation of rifampicin and ethyl cellulose

    CSIR Research Space (South Africa)

    Djerafi, R

    2017-05-01

    Full Text Available . Using the solvent mixture, co-precipitates with particle sizes ranging between 190 and 230 nm were obtained with drug loading and drug precipitation yield from respectively 8.5 to 38.5 and 42.4 to 77.2% when decreasing the ethyl cellulose...

  20. ASSESSING CHEMICAL HAZARDS AT THE PLUTONIUM FINISHING PLANT FOR PLANNING FUTURE DECONTAMINATION AND DECOMMISSIONING

    International Nuclear Information System (INIS)

    HOPKINS, A.M.; KLOS, D.B.; MINETT, M.J.

    2007-01-01

    This paper documents the fiscal year (FY) 2006 assessment to evaluate potential chemical and radiological hazards associated with vessels and piping in the former plutonium process areas at Hanford's Plutonium Finishing Plant (PFP). Evaluations by PFP engineers as design authorities for specific systems and other subject-matter experts were conducted to identify the chemical hazards associated with transitioning the process areas for the long-term layup of PFP before its eventual final decontamination and decommissioning (D and D). D and D activities in the main process facilities were suspended in September 2005 for a period of between 5 and 10 years. A previous assessment conducted in FY 2003 found that certain activities to mitigate chemical hazards could be deferred safely until the D and D of PFP, which had been scheduled to result in a slab-on-grade condition by 2009. As a result of necessary planning changes, however, D and D activities at PFP will be delayed until after the 2009 time frame. Given the extended project and plant life, it was determined that a review of the plant chemical hazards should be conducted. This review to determine the extended life impact of chemicals is called the ''Plutonium Finishing Plant Chemical Hazards Assessment, FY 2006''. This FY 2006 assessment addresses potential chemical and radiological hazard areas identified by facility personnel and subject-matter experts who reevaluated all the chemical systems (items) from the FY 2003 assessment. This paper provides the results of the FY 2006 chemical hazards assessment and describes the methodology used to assign a hazard ranking to the items reviewed

  1. Formation of Silica-Lysozyme Composites Through Co-Precipitation and Adsorption

    Directory of Open Access Journals (Sweden)

    Daniela B. van den Heuvel

    2018-04-01

    Full Text Available Interactions between silica and proteins are crucial for the formation of biosilica and the production of novel functional hybrid materials for a range of industrial applications. The proteins control both precipitation pathway and the properties of the resulting silica–organic composites. Here, we present data on the formation of silica–lysozyme composites through two different synthesis approaches (co-precipitation vs. adsorption and show that the chemical and structural properties of these composites, when analyzed using a combination of synchrotron-based scattering (total scattering and small-angle X-ray scattering, spectroscopic, electron microscopy, and potentiometric methods vary dramatically. We document that while lysozyme was not incorporated into nor did its presence alter the molecular structure of silica, it strongly enhanced the aggregation of silica particles due to electrostatic and potentially hydrophobic interactions, leading to the formation of composites with characteristics differing from pure silica. The differences increased with increasing lysozyme content for both synthesis approaches. Yet, the absolute changes differ substantially between the two sets of composites, as lysozyme did not just affect aggregation during co-precipitation but also particle growth and likely polymerization during co-precipitation. Our results improve the fundamental understanding of how organic macromolecules interact with dissolved and nanoparticulate silica and how these interactions control the formation pathway of silica–organic composites from sodium silicate solutions, a widely available and cheap starting material.

  2. Formation of Silica-Lysozyme Composites Through Co-Precipitation and Adsorption

    Science.gov (United States)

    van den Heuvel, Daniela B.; Stawski, Tomasz M.; Tobler, Dominique J.; Wirth, Richard; Peacock, Caroline L.; Benning, Liane G.

    2018-04-01

    Interactions between silica and proteins are crucial for the formation of biosilica and the production of novel functional hybrid materials for a range of industrial applications. The proteins control both precipitation pathway and the properties of the resulting silica-organic composites. Here we present data on the formation of silica-lysozyme composites through two different synthesis approaches (co-precipitation vs. adsorption) and show that the chemical and structural properties of these composites, when analyzed using a combination of synchrotron-based scattering (total scattering and SAXS), spectroscopic, electron microscopy and potentiometric methods vary dramatically. We document that while lysozyme was not incorporated into nor did its presence alter the molecular structure of silica, it strongly enhanced the aggregation of silica particles due to electrostatic and potentially hydrophobic interactions, leading to the formation of composites with characteristics differing from pure silica. The differences increased with increasing lysozyme content for both synthesis approaches. Yet, the absolute changes differ substantially between the two sets of composites, as lysozyme did not just affect aggregation during co-precipitation but also particle growth and likely polymerization during co-precipitation. Our results improve the fundamental understanding of how organic macromolecules interact with dissolved and nanoparticulate silica and how these interactions control the formation pathway of silica-organic composites from sodium silicate solutions, a widely available and cheap starting material.

  3. Results of chemical decontamination of DOE`s uranium-enrichment scrap metal

    Energy Technology Data Exchange (ETDEWEB)

    Levesque, R.G.

    1997-02-01

    The CORPEX{reg_sign} Nuclear Decontamination Processes were used to decontaminate representative scrap metal specimens obtained from the existing scrap metal piles located at the Department of Energy (DOE) Portsmouth Gaseous Diffusion Plant (PORTS), Piketon, Ohio. In September 1995, under contract to Lockheed Martin Energy Systems, MELE Associates, Inc. performed the on-site decontamination demonstration. The decontamination demonstration proved that significant amounts of the existing DOE scrap metal can be decontaminated to levels where the scrap metal could be economically released by DOE for beneficial reuse. This simple and environmentally friendly process can be used as an alternative, or in addition to, smelting radiologically contaminated scrap metal.

  4. Dissolution of magnetite in a dilute chemical decontaminant formulation containing gallic acid as a reductant

    International Nuclear Information System (INIS)

    Kishore, Kamal; Rajesh, Puspalata; Dey, G.R.

    2000-01-01

    Gallic acid (GA) was tried as a reductant in place of ascorbic acid in dilute chemical decontaminant (DCD) formulations. Dissolution of magnetite in GA based DCD formulations was studied at 50 deg as well as 80 degC. It was found to be a good substitute for ascorbic acid in EDTA/ascorbic acid/citric acid i.e. EAC formulation. The efficiency of EDTA/GA/CA formulation was as good as that of EAC formulation. 2.8 was found to be the optimum pH for this formulation and dissolution decreased at lower as well as higher pHs. The ion-exchange behaviour of GA is also appropriate for using it in a regenerating type of formulation. Being an aromatic compound, gallic acid has inherent stability against radiation degradation. (author)

  5. A dilute chemical decontaminant formulation containing gallic acid as a reductant

    International Nuclear Information System (INIS)

    Kishore, K.; Rajesh, P.; Kumbhar, A.G.

    2001-01-01

    Gallic acid (GA) was tried as a reductant in place of ascorbic acid in dilute chemical decontaminant (DCD) formulations. Dissolution of magnetite in GA based DCD formulations was studied at 50 C as well as 80 C. It was found to be a good substitute for ascorbic acid in EDTA/ascorbic acid/citric acid, i.e., EAC formulation. The efficiency of EDTA/GA/CA formulation was as good as that of EAC formulation. 2.8 was found to be the optimum pH for this formulation and dissolution decreased at lower as well as higher pHs. The ion exchange behaviour of GA is also appropriate for using it in a regenerating type of formulation. Being an aromatic compound, Gallic acid has inherent stability against radiation degradation. (orig.)

  6. Radiation degradation and the consequent decrease in the efficacy of some dilute chemical decontaminant formulations

    Energy Technology Data Exchange (ETDEWEB)

    Kamal Kishore; Dey, G.R.; Naik, D.B.; Moorthy, P.N. [Applied Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India)

    1998-12-31

    Constituents of dilute chemical decontaminant formulations such as ascorbic acid, EDTA, picolinic acid (PA) and 2,6-pyridine dicarboxylic acid (PDCA), also known as dipicolinic acid, are highly reactive with primary species produced from water radiolysis. Picolinic acid and PDCA however, are less sensitive to radiation dose due to their aromatic nature. They also help in protecting ascorbic acid when in a mixture. The efficacy for dissolution of magnetite was found to reduce drastically on irradiation in the case of EDTA/oxalic acid/citric acid while it was unaffected in the case of picolinic acid/ascorbic acid. In the case of EDTA/ascorbic acid/citric acid or PDCA/ascorbic acid formulations, there was only a marginal effect of radiation on the efficacy of the formulations. (author)

  7. Decontamination of adsorbed chemical warfare agents on activated carbon using hydrogen peroxide solutions.

    Science.gov (United States)

    Osovsky, Ruth; Kaplan, Doron; Nir, Ido; Rotter, Hadar; Elisha, Shmuel; Columbus, Ishay

    2014-09-16

    Mild treatment with hydrogen peroxide solutions (3-30%) efficiently decomposes adsorbed chemical warfare agents (CWAs) on microporous activated carbons used in protective garments and air filters. Better than 95% decomposition of adsorbed sulfur mustard (HD), sarin, and VX was achieved at ambient temperatures within 1-24 h, depending on the H2O2 concentration. HD was oxidized to the nontoxic HD-sulfoxide. The nerve agents were perhydrolyzed to the respective nontoxic methylphosphonic acids. The relative rapidity of the oxidation and perhydrolysis under these conditions is attributed to the microenvironment of the micropores. Apparently, the reactions are favored due to basic sites on the carbon surface. Our findings suggest a potential environmentally friendly route for decontamination of adsorbed CWAs, using H2O2 without the need of cosolvents or activators.

  8. Development of standards for chemical and biological decontamination of buildings and structures affected by terrorism

    Energy Technology Data Exchange (ETDEWEB)

    Lumley, T.C.; Volchek, K.; Fingas, M. [Environment Canada, Ottawa, ON (Canada). Emergencies Science and Technology Division, Environmental Technology Centre, Science and Technology Branch; Hay, A.W.M. [Leeds Univ., Leeds (United Kingdom)

    2006-07-01

    Currently, there are no suitable standards for determining levels of safety when reoccupying a building that has been recommissioned following a biological or chemical attack. For that reason, this study focused on developing clean-up standards for decontaminating buildings and construction materials after acts of terrorism. Several parameters must be assessed when determining the course of action to decontaminate toxic agents and to rehabilitate facilities. First, the hazardous substance must be positively identified along with the degree of contamination and information on likely receptors. Potential exposure route is also a key consideration in the risk assessment process. A key objective of the study was to develop specific guidelines for ascertaining and defining clean. In particular, standards for chemical and biological agents that pose a real or potential risk for use as agents of terrorism will be developed. The selected agents for standards development were ammonia, fentanyl, malathion, mustard gas, potassium cyanide, ricin, sarin, hepatitis A virus, and bacillus anthracis. The standards will be developed by establishing the relationship between the amount of exposure and expected health effects; assessing real and potential risks by identifying individuals at risk and consideration of all exposure routes; and, characterizing the risk to determine the potential for toxicity or infectivity. For non-carcinogens, this was done through the analysis of other known guidelines. Cancer-slope factors will be considered for carcinogens. The standards will be assessed in the laboratory using animal models. The guidelines and standards are intended for first-responders and are scheduled for development by the end of 2006. 15 refs., 3 tabs.

  9. Decontamination and decommissioning of the Chemical Process Cell (CPC): Topical report for the period January 1985-March 1987

    International Nuclear Information System (INIS)

    Meigs, R.A.

    1987-07-01

    To support interim storage of vitrified High-Level Waste (HLW) at the West Valley Demonstration Project, the shielded, remotely operated Chemical Process Cell (CPC) was decommissioned and decontaminated. All equipment was removed, packaged and stored for future size reduction and decontamination. Floor debris was sampled, characterized, and vacuumed into remotely handled containers. The cell walls, ceiling, and floor were decontaminated. Three 20 Mg (22.5 ton) concrete neutron absorber cores were cut with a high-pressure water/abrasive jet cutting system and packaged for disposal. All operations were performed remotely using two overhead bridge cranes which included two 1.8 Mg (2 ton) hoists, one 14.5 Mg (16 ton) hoist, and an electromechanical manipulator or an industrial robot mounted on a mobile platform. Initial general area dose rates in the cell ranged from 1 to 50 R/h. Target levels of less than 10 mR/h general area readings were established before decontamination and decommissioning was initiated; general area dose rates between 200 mR/h and 1200 mR/h were obtained at the completion of the decontamination work. 4 refs., 11 figs., 8 tabs

  10. Nuclear decontamination

    International Nuclear Information System (INIS)

    LeSurf, J.E.

    1981-01-01

    Decontamination may be accomplished by chemical, electrical, or mechanical means. Recently there have been significant developments in all three categories as well as an increased tendency to combine techniques, either simultaneously (e.g. by adding chemicals to water jets) or sequentially (e.g. by using a mechanical method to remove loose contamination, followed by a chemical method for more tightly bound activity). Some developments in the different techniques are discussed, together with typical applications of each. (author)

  11. Reactive decontamination formulation

    Science.gov (United States)

    Giletto, Anthony [College Station, TX; White, William [College Station, TX; Cisar, Alan J [Cypress, TX; Hitchens, G Duncan [Bryan, TX; Fyffe, James [Bryan, TX

    2003-05-27

    The present invention provides a universal decontamination formulation and method for detoxifying chemical warfare agents (CWA's) and biological warfare agents (BWA's) without producing any toxic by-products, as well as, decontaminating surfaces that have come into contact with these agents. The formulation includes a sorbent material or gel, a peroxide source, a peroxide activator, and a compound containing a mixture of KHSO.sub.5, KHSO.sub.4 and K.sub.2 SO.sub.4. The formulation is self-decontaminating and once dried can easily be wiped from the surface being decontaminated. A method for decontaminating a surface exposed to chemical or biological agents is also disclosed.

  12. Locus-specific microemulsion catalysts for sulfur mustard (HD) chemical warfare agent decontamination.

    Science.gov (United States)

    Fallis, Ian A; Griffiths, Peter C; Cosgrove, Terence; Dreiss, Cecile A; Govan, Norman; Heenan, Richard K; Holden, Ian; Jenkins, Robert L; Mitchell, Stephen J; Notman, Stuart; Platts, Jamie A; Riches, James; Tatchell, Thomas

    2009-07-22

    The rates of catalytic oxidative decontamination of the chemical warfare agent (CWA) sulfur mustard (HD, bis(2-chlororethyl) sulfide) and a range (chloroethyl) sulfide simulants of variable lipophilicity have been examined using a hydrogen peroxide-based microemulsion system. SANS (small-angle neutron scattering), SAXS (small-angle X-ray scattering), PGSE-NMR (pulsed-gradient spin-echo NMR), fluorescence quenching, and electrospray mass spectroscopy (ESI-MS) were implemented to examine the distribution of HD, its simulants, and their oxidation/hydrolysis products in a model oil-in-water microemulsion. These measurements not only present a means of interpreting decontamination rates but also a rationale for the design of oxidation catalysts for these toxic materials. Here we show that by localizing manganese-Schiff base catalysts at the oil droplet-water interface or within the droplet core, a range of (chloroethyl) sulfides, including HD, spanning some 7 orders of octanol-water partition coefficient (K(ow)), may be oxidized with equal efficacy using dilute (5 wt. % of aqueous phase) hydrogen peroxide as a noncorrosive, environmentally benign oxidant (e.g., t(1/2) (HD) approximately 18 s, (2-chloroethyl phenyl sulfide, C(6)H(5)SCH(2)CH(2)Cl) approximately 15 s, (thiodiglycol, S(CH(2)CH(2)OH)(2)) approximately 19 s {20 degrees C}). Our observations demonstrate that by programming catalyst lipophilicity to colocalize catalyst and substrate, the inherent compartmentalization of the microemulsion can be exploited to achieve enhanced rates of reaction or to exert control over product selectivity. A combination of SANS, ESI-MS and fluorescence quenching measurements indicate that the enhanced catalytic activity is due to the locus of the catalyst and not a result of partial hydrolysis of the substrate.

  13. Study of calcium carbonate and sulfate co-precipitation

    KAUST Repository

    Zarga, Y.

    2013-06-01

    Co-precipitation of mineral based salts in scaling is still not well understood and/or thermodynamically well defined in the water industry. This study focuses on investigating calcium carbonate (CaCO3) and sulfate mixed precipitation in scaling which is commonly observed in industrial water treatment processes including seawater desalination either by thermal-based or membrane-based processes. Co-precipitation kinetics were studied carefully by monitoring several parameters simultaneously measured, including: pH, calcium and alkalinity concentrations as well as quartz microbalance responses. The CaCO3 germination in mixed precipitation was found to be different than that of simple precipitation. Indeed, the co-precipitation of CaCO3 germination time was not anymore related to supersaturation as in a simple homogenous precipitation, but was significantly reduced when the gypsum crystals appeared first. On the other hand, the calcium sulfate crystals appear to reduce the energetic barrier of CaCO3 nucleation and lead to its precipitation by activating heterogeneous germination. However, the presence of CaCO3 crystals does not seem to have any significant effect on gypsum precipitation. IR spectroscopy and the Scanning Electronic Microscopy (SEM) were used to identify the nature of scales structures. Gypsum was found to be the dominant precipitate while calcite and especially vaterite were found at lower proportions. These analyses showed also that gypsum crystals promote calcite crystallization to the detriment of other forms. © 2013 Elsevier Ltd.

  14. Aqueous media treatment and decontamination of hazardous chemical and biological substances by contact plasma

    International Nuclear Information System (INIS)

    Pivovarov, A.; Kravchenko, A.; Kublanovsky, V.

    2009-01-01

    Usage of non-equilibrium contact plasma for processes of decontamination and neutralization in conditions of manifestation of chemical, biological and radiation terrorism takes on special significance due to portability of equipment and its mobility in places where toxic liquid media hazardous for people's health are located. Processes of decontamination of aqueous media, seminated with pathogenic microorganisms and viruses, treatment of water containing toxic heavy metals, cyanides, surface-active substances, and heavy radioactive elements, are investigated. Examples of activation processes in infected water and toxic aqueous solutions present convincing evidence of the way, how new quality technological approach for achievement of high enough degree of the said media treatment is used in each specific case. Among new properties of water activated as a result of action of non-equilibrium contact plasma, it is necessary to mention presence of cluster structure, confirmed by well-known spectral and physical-chemical methods, presence of peroxide compounds, active particles and radicals. Anti-microbial activity which is displayed under action of plasma in aqueous media (chemically pure water, drinking water, aqueous solutions of sodium chloride, potassium iodide, as well as other inorganic compounds) towards wide range of pathogenic and conventionally pathogenic microorganisms allows use them as reliable, accessible and low-cost preparations for increasing the degree of safety of food products. Combination of such processes with known methods of filtration and ultra-filtration gives an efficient and available complex capable of withstanding any threats, which may arise for population and living organisms. Present-day level of machine-building, electrical engineering, and electronics allows predict creation of industrial plasma installations, adapted to conditions of various terrorist threats, with minimized power consumption and optimized technological parameters

  15. Aqueous media treatment and decontamination of hazardous chemical and biological substances by contact plasma

    Energy Technology Data Exchange (ETDEWEB)

    Pivovarov, A; Kravchenko, A [Ukrainian State University of Chemical Engineering, Dnepropetrovsk (Ukraine); Kublanovsky, V [V. I. Vernadsky Institute of General and Inorganic Chemistry of National Academy of Science, Kiev (Ukraine)

    2009-07-01

    Usage of non-equilibrium contact plasma for processes of decontamination and neutralization in conditions of manifestation of chemical, biological and radiation terrorism takes on special significance due to portability of equipment and its mobility in places where toxic liquid media hazardous for people's health are located. Processes of decontamination of aqueous media, seminated with pathogenic microorganisms and viruses, treatment of water containing toxic heavy metals, cyanides, surface-active substances, and heavy radioactive elements, are investigated. Examples of activation processes in infected water and toxic aqueous solutions present convincing evidence of the way, how new quality technological approach for achievement of high enough degree of the said media treatment is used in each specific case. Among new properties of water activated as a result of action of non-equilibrium contact plasma, it is necessary to mention presence of cluster structure, confirmed by well-known spectral and physical-chemical methods, presence of peroxide compounds, active particles and radicals. Anti-microbial activity which is displayed under action of plasma in aqueous media (chemically pure water, drinking water, aqueous solutions of sodium chloride, potassium iodide, as well as other inorganic compounds) towards wide range of pathogenic and conventionally pathogenic microorganisms allows use them as reliable, accessible and low-cost preparations for increasing the degree of safety of food products. Combination of such processes with known methods of filtration and ultra-filtration gives an efficient and available complex capable of withstanding any threats, which may arise for population and living organisms. Present-day level of machine-building, electrical engineering, and electronics allows predict creation of industrial plasma installations, adapted to conditions of various terrorist threats, with minimized power consumption and optimized technological parameters

  16. Comparison of dilute chemical decontaminations of RAPS-2 full primary heat transport system

    International Nuclear Information System (INIS)

    Bhat, H.R.

    2000-01-01

    First ever attempt to decontaminate a full primary system of an Indian PHWR was carried out at Rajasthan Atomic Power Station Unit -2 (RAPS-2) in August 1992. The decontamination factors obtained were moderate. The second attempt to decontaminate the same system was made in February 1996 with a different formulation. The decontamination factors obtained were lesser than the earlier attempt. The details of the two campaigns and their relative merits and demerits are discussed. Some more studies are required to be done before further implementation of the picolonic acid/ascorbic acid formulation. The 1992 attempt was with picolinic acid and ascorbic acid whereas the 1996 attempt was with EDTA + citric acid + ascorbic Acid (EAC ) formulation. A number of lessons were learnt from the first campaign and the improvements were applied during the subsequent decontamination campaigns at Madras Atomic Power station. The total iron removed and various radio nuclides removed are also detailed in the paper. Picolonic acid and ascorbic acid is a better formulation for decontamination of full PHT systems of Indian PHWRs. Use of EAC formulation generates a lot of crud which settles in narrow clearances. Picolonic Acid/Ascorbic Acid formulation does not generate any crud. Decontamination using a single cycle of the picolonic acid/ascorbic acid formulation is more effective than the decontamination using three cycles of EAC formulation. (author)

  17. Radioactive decontamination

    International Nuclear Information System (INIS)

    1983-07-01

    This Code of Practice covers: (a) the decontamination of plant items, buildings and associated equipment; (b) decontamination of protective clothing; (c) simple personal decontamination; and (d) the basic mechanisms of contamination and their influence on decontaminability. (author)

  18. Chemical decontamination and melt densification of chop-leach fuel hulls

    International Nuclear Information System (INIS)

    Dillon, R.L.; Griggs, B.; Kemper, R.S.; Nelson, R.G.

    1976-01-01

    This paper reports on decontamination and densification studies of chop-leach fuel hull residues designed to minimize the transuranic element (TRU) contaminated waste stream. Decontamination requirements have been established from studies of TRU element distribution in the fuel hull residues. Effective surface decontamination of Zircaloy requires removal of zirconium oxide corrosion products. Good decontamination factors have been achieved with aqueous solutions following high temperature HF conditioning of oxide films. Molten fluoride salt mixtures are effective decontaminants, but pose problems in metal loss and salt dragout. Molten metal decontamination methods are highly preliminary, but may be required to reduce TRU originating from tramp uranium in Zircaloy. Low melting (1300 0 C) alloy of Zircaloy, stainless steel, and Inconel have been prepared in induction heated graphite crucibles. High quality ingots of Zircaloy-2 have been prepared directly from short sections of descaled fuel clad tubing using the Inductoslag process. This material is readily capable of refabrication. Inductoslag melts have also been prepared from heavily oxidized Zircaloy tubing demonstrating melt densification without prior decontamination is technically feasible. Hydrogen absorption kinetics have been demonstrated with cast Zircaloy-2 and cast Zircaloy-stainless steel-Inconel alloys. Metallic fuel hull residues have been proposed as a storage medium for tritium released from fuel during reprocessing. (author)

  19. Efficacy studies of Reactive Skin Decontamination Lotion, M291 Skin Decontamination Kit, 0.5% bleach, 1% soapy water, and Skin Exposure Reduction Paste Against Chemical Warfare Agents, part 2: guinea pigs challenged with soman.

    Science.gov (United States)

    Braue, Ernest H; Smith, Kelly H; Doxzon, Bryce F; Lumpkin, Horace L; Clarkson, Edward D

    2011-03-01

    This report, the second in a series of five, directly compares the efficacy of Reactive Skin Decontamination Lotion (RSDL), the M291 Skin Decontamination Kit (SDK), 0.5% bleach (sodium or calcium hypochlorite solution), 1% soapy water, and Skin Exposure Reduction Paste Against Chemical Warfare Agents (SERPACWA) in the haired guinea pig model following exposure to soman (GD). In all experiments, guinea pigs were close-clipped and given anesthesia. In the decontamination experiments, the animals were challenged with GD and decontaminated after a 2-minute delay for the standard procedure or at longer times for the delayed-decontamination experiments. Positive control animals were challenged with GD in the same manner as the treated animals, except that they received no treatment. All animals were observed during the first 4 hours and again at 24 hours after exposure for signs of toxicity and death. The protective ratio (PR, defined as the median lethal dose [LD(50)] of the treatment group divided by the LD(50) of the untreated positive control animals) was calculated from the derived probit dose-response curves established for each treatment group and nontreated control animals. SERPACWA was applied as a thin coating (0.1 mm thick), allowed to dry for 15 minutes, and challenged with GD. After a 2-hour challenge, any remaining GD was blotted off the animal, but no additional decontamination was done. Significance in this report is defined as p decontamination experiments, the calculated PRs for RSDL, 0.5% bleach, 1% soapy water, and M291 SDK were 14, 2.7, 2.2, and 2.6, respectively. RSDL was by far the most effective decontamination product tested and significantly better than any of the other products. Bleach, soapy water, and the M291 SDK provided equivalent and modest protection. Since only RSDL provided at least good protection (PR > 5), it was the only decontamination product evaluated for delayed decontamination. In the GD delayed-decontamination experiments

  20. Remanence properties of Co-precipitated cobalt ferrite

    International Nuclear Information System (INIS)

    Bueno-Baques, D.; Medina-Boudri, Angela; Matutes-Aquino, J.

    2001-01-01

    Isothermal remanent magnetization (IRM) and DC demagnetization (DCD) curves of a co-precipitated cobalt ferrite sample were obtained. From the IRM and DCD data, the Henkel plot was obtained and analyzed in the Preisach model framework. The Henkel plot data are below the Wohlfarth line that indicates a dominant local disorder (demagnetizing-like effect). Forward and reverse switching field distribution curves were obtained from differentiation of the IRM and DCD curves. The peak values of these switching field distributions differ by a factor of about 2.7

  1. Fate of the chemical warfare agent O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate (VX) on soil following accelerant-based fire and liquid decontamination.

    Science.gov (United States)

    Gravett, M R; Hopkins, F B; Self, A J; Webb, A J; Timperley, C M; Riches, J R

    2014-08-01

    In the event of alleged use of organophosphorus nerve agents, all kinds of environmental samples can be received for analysis. These might include decontaminated and charred matter collected from the site of a suspected chemical attack. In other scenarios, such matter might be sampled to confirm the site of a chemical weapon test or clandestine laboratory decontaminated and burned to prevent discovery. To provide an analytical capability for these contingencies, we present a preliminary investigation of the effect of accelerant-based fire and liquid decontamination on soil contaminated with the nerve agent O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate (VX). The objectives were (a) to determine if VX or its degradation products were detectable in soil after an accelerant-based fire promoted by aviation fuel, including following decontamination with Decontamination Solution 2 (DS2) or aqueous sodium hypochlorite, (b) to develop analytical methods to support forensic analysis of accelerant-soaked, decontaminated and charred soil and (c) to inform the design of future experiments of this type to improve analytical fidelity. Our results show for the first time that modern analytical techniques can be used to identify residual VX and its degradation products in contaminated soil after an accelerant-based fire and after chemical decontamination and then fire. Comparison of the gas chromatography-mass spectrometry (GC-MS) profiles of VX and its impurities/degradation products from contaminated burnt soil, and burnt soil spiked with VX, indicated that the fire resulted in the production of diethyl methylphosphonate and O,S-diethyl methylphosphonothiolate (by an unknown mechanism). Other products identified were indicative of chemical decontamination, and some of these provided evidence of the decontaminant used, for example, ethyl 2-methoxyethyl methylphosphonate and bis(2-methoxyethyl) methylphosphonate following decontamination with DS2. Sample preparation

  2. Evaluation of three different decontamination techniques on biofilm formation, and on physical and chemical properties of resin composites.

    Science.gov (United States)

    André, Carolina Bosso; Dos Santos, Andressa; Pfeifer, Carmem Silvia; Giannini, Marcelo; Girotto, Emerson Marcelo; Ferracane, Jack Liborio

    2018-04-01

    This study evaluated three different sterilization/disinfection techniques for resin composites on bacterial growth and surface modification after decontamination. Two resin composites were sterilized/disinfected with three different techniques: UV light, 1% chloramine T, and 70% ethanol. Four different times were used for each technique to determine the shortest time that the solution or UV light was effective. The influence of sterilization/disinfection technique on bacterial growth was evaluated by analyzing the metabolic activity, using the AlamarBlue™ assay, bacterial viability, and SEM images from biofilms of Streptococcus mutans. The surface change, after the process, was analyzed with ATR/FTIR and SEM images. The solutions used for decontamination (1% chloramine-T and 70% ethanol) were analyzed with 1 H-NMR to identify any resin compounds leached during the process. One minute of decontamination was efficient for all three methods tested. Chloramine-T increased the surface porosity on resin composites, no changes were observed for UV light and 70% ethanol, however, 1 H-NMR identified leached monomers only when 70% ethanol was used. No chemical change of the materials was found under ATR/FTIR analyses after the decontamination process. Chloramine-T, with no previous wash, increased the bacterial viability for both resin composites and increased the bacterial metabolism for the resin composite without fluoride. UV light had no interference on the resin composites properties tested using 1 min of exposure compared to the other decontamination methods. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 945-953, 2018. © 2017 Wiley Periodicals, Inc.

  3. Low corrosive chemical decontamination method using pH control. 1. Basic system

    International Nuclear Information System (INIS)

    Nagase, Makoto; Ishida, Kazushige; Uetake, Naohito; Anazawa, Kazumi; Nakamura, Fumito; Yoshikawa, Hiroo; Tamagawa, Tadashi; Furukawa, Kiyoharu

    2001-01-01

    A new low corrosive decontamination method was developed which uses both oxalic acid and hydrazine as the reducing agent and potassium permanganate as the oxidizing agent. Less corrosion of structural materials during the decontamination is realized by pH control of the reducing agent. The pH of 2.5, attained by adding hydrazine to oxalic acid, was the optimum pH for maintaining a high decontamination effect and lowering the corrosion at the same time. As this reducing agent can be decomposed into carbon dioxide, nitrogen and water by using a catalyst column with hydrogen peroxide, the amount of secondary radioactive waste is small. These good features were demonstrated through actual plant decontamination tasks. (author)

  4. Vaporous Decontamination Methods: Potential Uses and Research Priorities for Chemical and Biological Contamination Control

    Science.gov (United States)

    2006-06-01

    over time. Ammonia gas is typically used to neutralise formaldehyde forming a white precipitate, hexamethylene- tetramine, which is then washed down...sulphite scrubbers DSTO-GD-0465 4 and a carbon bed to prevent any leakage of the ClO2 gas into the environment. The decontamination period (12...of ammonia gas) produces a broad-spectrum decontaminant against C agents [7]. However, initial studies have shown that the modified vaporous

  5. Reducing the Risks. In the aftermath of a terrorist attack, wastewater utilities may have to contend with decontamination water containing chemical, biological, or radiological substances

    International Nuclear Information System (INIS)

    Warren, Linda P.; Hornback, Chris; Strom, Daniel J.

    2006-01-01

    In the aftermath of a chemical, biological, or radiological (CBR) attack, decontamination of people and infrastructure will be needed. Decontamination inevitably produces wastewater, and wastewater treatment plants (WTPs) need to know how to handle decontamination wastewater. This article describes CBR substances; planning, coordinating, and communicating responses across agencies; planning within a utility; coordination with local emergency managers and first responders; mitigating effects of decontamination wastewater; and mitigating effects on utility personnel. Planning for Decontamination Wastewater: A Guide for Utilities, the document on which this article is based, was developed under a cooperative agreement from the U.S. Environmental Protection Agency by the National Association of Clean Water Agencies (NACWA) and its contractor, CH2MHILL, Inc.

  6. Development of chemical decontamination process with sulfuric acid-cerium (IV) for decommissioning

    International Nuclear Information System (INIS)

    Suwa, Takeshi; Kuribayashi, Nobuhide; Tachikawa, Enzo

    1988-01-01

    The electrolytic regeneration of Ce 4+ from Ce 3+ , which is required to achieve a high decontamination factor (DF) in this process, has been investigated. A calculating model was derived for the regenerating current required during the decontamination as a function of dissolution rate of crud, corrosion rate (R c ), current efficiency (η e ) and characteristics of decontamination loop. From the above calculation, it was found that the current was mainly governed by R c and η e . A condition to obtain a high DF at low R c and high η e has been found experimentally by use of a mixture of Ce 3+ at the ratio of Ce 4+ /Ce 3+ = 0.1 ∼ 0.2. The desired values to be η e ≥ 80 % at above 50 A/m 2 was obtained under the flow rate above 300 cm/min and Ce 3+ concentration above 10 x 10 -3 M at 60 deg C using the dual-cylindrical type cell. The current efficiency was also investigated with cells of various geometries. The present decontamination process has been proposed as a system decontamination process, which is essentially a single-step decontamination process for Cr-rich oxides. (author)

  7. Effective Responder Communication Improves Efficiency and Psychological Outcomes in a Mass Decontamination Field Experiment: Implications for Public Behaviour in the Event of a Chemical Incident

    Science.gov (United States)

    Carter, Holly; Drury, John; Amlôt, Richard; Rubin, G. James; Williams, Richard

    2014-01-01

    The risk of incidents involving mass decontamination in response to a chemical, biological, radiological, or nuclear release has increased in recent years, due to technological advances, and the willingness of terrorists to use unconventional weapons. Planning for such incidents has focused on the technical issues involved, rather than on psychosocial concerns. This paper presents a novel experimental study, examining the effect of three different responder communication strategies on public experiences and behaviour during a mass decontamination field experiment. Specifically, the research examined the impact of social identity processes on the relationship between effective responder communication, and relevant outcome variables (e.g. public compliance, public anxiety, and co-operative public behaviour). All participants (n = 111) were asked to visualise that they had been involved in an incident involving mass decontamination, before undergoing the decontamination process, and receiving one of three different communication strategies: 1) ‘Theory-based communication’: Health-focused explanations about decontamination, and sufficient practical information; 2) ‘Standard practice communication’: No health-focused explanations about decontamination, sufficient practical information; 3) ‘Brief communication’: No health-focused explanations about decontamination, insufficient practical information. Four types of data were collected: timings of the decontamination process; observational data; and quantitative and qualitative self-report data. The communication strategy which resulted in the most efficient progression of participants through the decontamination process, as well as the fewest observations of non-compliance and confusion, was that which included both health-focused explanations about decontamination and sufficient practical information. Further, this strategy resulted in increased perceptions of responder legitimacy and increased

  8. Effective responder communication improves efficiency and psychological outcomes in a mass decontamination field experiment: implications for public behaviour in the event of a chemical incident.

    Science.gov (United States)

    Carter, Holly; Drury, John; Amlôt, Richard; Rubin, G James; Williams, Richard

    2014-01-01

    The risk of incidents involving mass decontamination in response to a chemical, biological, radiological, or nuclear release has increased in recent years, due to technological advances, and the willingness of terrorists to use unconventional weapons. Planning for such incidents has focused on the technical issues involved, rather than on psychosocial concerns. This paper presents a novel experimental study, examining the effect of three different responder communication strategies on public experiences and behaviour during a mass decontamination field experiment. Specifically, the research examined the impact of social identity processes on the relationship between effective responder communication, and relevant outcome variables (e.g. public compliance, public anxiety, and co-operative public behaviour). All participants (n = 111) were asked to visualise that they had been involved in an incident involving mass decontamination, before undergoing the decontamination process, and receiving one of three different communication strategies: 1) 'Theory-based communication': Health-focused explanations about decontamination, and sufficient practical information; 2) 'Standard practice communication': No health-focused explanations about decontamination, sufficient practical information; 3) 'Brief communication': No health-focused explanations about decontamination, insufficient practical information. Four types of data were collected: timings of the decontamination process; observational data; and quantitative and qualitative self-report data. The communication strategy which resulted in the most efficient progression of participants through the decontamination process, as well as the fewest observations of non-compliance and confusion, was that which included both health-focused explanations about decontamination and sufficient practical information. Further, this strategy resulted in increased perceptions of responder legitimacy and increased identification with

  9. Effective responder communication improves efficiency and psychological outcomes in a mass decontamination field experiment: implications for public behaviour in the event of a chemical incident.

    Directory of Open Access Journals (Sweden)

    Holly Carter

    Full Text Available The risk of incidents involving mass decontamination in response to a chemical, biological, radiological, or nuclear release has increased in recent years, due to technological advances, and the willingness of terrorists to use unconventional weapons. Planning for such incidents has focused on the technical issues involved, rather than on psychosocial concerns. This paper presents a novel experimental study, examining the effect of three different responder communication strategies on public experiences and behaviour during a mass decontamination field experiment. Specifically, the research examined the impact of social identity processes on the relationship between effective responder communication, and relevant outcome variables (e.g. public compliance, public anxiety, and co-operative public behaviour. All participants (n = 111 were asked to visualise that they had been involved in an incident involving mass decontamination, before undergoing the decontamination process, and receiving one of three different communication strategies: 1 'Theory-based communication': Health-focused explanations about decontamination, and sufficient practical information; 2 'Standard practice communication': No health-focused explanations about decontamination, sufficient practical information; 3 'Brief communication': No health-focused explanations about decontamination, insufficient practical information. Four types of data were collected: timings of the decontamination process; observational data; and quantitative and qualitative self-report data. The communication strategy which resulted in the most efficient progression of participants through the decontamination process, as well as the fewest observations of non-compliance and confusion, was that which included both health-focused explanations about decontamination and sufficient practical information. Further, this strategy resulted in increased perceptions of responder legitimacy and increased

  10. Decontamination of chemical and biological warfare agents with a single multi-functional material.

    Science.gov (United States)

    Amitai, Gabi; Murata, Hironobu; Andersen, Jill D; Koepsel, Richard R; Russell, Alan J

    2010-05-01

    We report the synthesis of new polymers based on a dimethylacrylamide-methacrylate (DMAA-MA) co-polymer backbone that support both chemical and biological agent decontamination. Polyurethanes containing the redox enzymes glucose oxidase and horseradish peroxidase can convert halide ions into active halogens and exert striking bactericidal activity against gram positive and gram negative bacteria. New materials combining those biopolymers with a family of N-alkyl 4-pyridinium aldoxime (4-PAM) halide-acrylate co-polymers offer both nucleophilic activity for the detoxification of organophosphorus nerve agents and internal sources of halide ions for generation of biocidal activity. Generation of free bromine and iodine was observed in the combined material resulting in bactericidal activity of the enzymatically formed free halogens that caused complete kill of E. coli (>6 log units reduction) within 1 h at 37 degrees C. Detoxification of diisopropylfluorophosphate (DFP) by the polyDMAA MA-4-PAM iodide component was dose-dependent reaching 85% within 30 min. A subset of 4-PAM-halide co-polymers was designed to serve as a controlled release reservoir for N-hydroxyethyl 4-PAM (HE 4-PAM) molecules that reactivate nerve agent-inhibited acetylcholinesterase (AChE). Release rates for HE 4-PAM were consistent with hydrolysis of the HE 4-PAM from the polymer backbone. The HE 4-PAM that was released from the polymer reactivated DFP-inhibited AChE at a similar rate to the oxime antidote 4-PAM. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  11. Decontamination device for pipeline

    International Nuclear Information System (INIS)

    Harashina, Heihachi.

    1994-01-01

    Pipelines to be decontaminated are parts of pipelines contaminated with radioactive materials, and they are connected to a fluid transfer means (for example, a bladeless pump) and a ball collector by way of a connector. The fluid of a mixture of chemical decontaminating liquid and spheres is sent into pipelines to be decontaminated. The spheres are, for example, heat resistant porous hard or soft rubber spheres. The fluid discharged from the pipelines to be decontaminated are circulated by way of bypassing means. The inner surface of the pipelines is decontaminated by the circulation of the fluid. When the bypass means is closed, the fluid discharged from the pipelines to be decontaminated is sent to the ball collector, and the spheres are captured by a hopper. Further, the liquid is sent to the filtrating means to filter the chemical contaminating liquid, and sludges contained in the liquid are captured. (I.N.)

  12. Concrete decontamination scoping tests

    International Nuclear Information System (INIS)

    Archibald, K.E.

    1995-01-01

    This report details the research efforts and scoping tests performed at the Idaho Chemical Process Plant using scabbling, chemical, and electro-osmotic decontamination techniques on radiologically contaminated concrete

  13. Chemical decontamination of the residual heat removal system (RHRS) of Flamanville 1

    International Nuclear Information System (INIS)

    Steinkuhler, Claude; Coomans, Reginald; Koen, Lenie

    2007-01-01

    The purpose of the decontamination of the RHRS at Flamanville 1 was the reduction of the general dosimetry and the elimination of hot spots. This was done to allow the maintenance on the RHRS equipment. The main challenge of this project was the execution of a complicated operation on the critical path of a shutdown. The redox attack of the oxides at the surface of the circuit in Flamanville, was performed by an EDF qualified process of the EMMAC family. The functions required by the decontamination system were very diverse and therefore an existing decontamination loop, which was previously developed for the decontamination of small system volumes, was re-developed and adapted for bigger circuits. Due to different reasons, an important delay on the planning happened. Therefore, only one cycle EMMAg was performed, totalling 2 hours of decontamination. Despite this, a DRRF (dose rate reduction factor) of 3,7 average was reached. The re-designed equipment and a shortened process were validated during this project. An acceptable DRRF was reached with no delay on the critical path. The capability of maintenance on the RHRS equipment is recovered with a gain of factor 5 on dosimetry. (authors)

  14. Preliminary evaluation of military, commercial and novel skin decontamination products against a chemical warfare agent simulant (methyl salicylate).

    Science.gov (United States)

    Matar, Hazem; Guerreiro, Antonio; Piletsky, Sergey A; Price, Shirley C; Chilcott, Robert P

    2016-01-01

    Rapid decontamination is vital to alleviate adverse health effects following dermal exposure to hazardous materials. There is an abundance of materials and products which can be utilised to remove hazardous materials from the skin. In this study, a total of 15 products were evaluated, 10 of which were commercial or military products and five were novel (molecular imprinted) polymers. The efficacies of these products were evaluated against a 10 µl droplet of (14)C-methyl salicylate applied to the surface of porcine skin mounted on static diffusion cells. The current UK military decontaminant (Fuller's earth) performed well, retaining 83% of the dose over 24 h and served as a benchmark to compare with the other test products. The five most effective test products were Fuller's earth (the current UK military decontaminant), Fast-Act® and three novel polymers [based on itaconic acid, 2-trifluoromethylacrylic acid and N,N-methylenebis(acrylamide)]. Five products (medical moist-free wipes, 5% FloraFree™ solution, normal baby wipes, baby wipes for sensitive skin and Diphotérine™) enhanced the dermal absorption of (14)C-methyl salicylate. Further work is required to establish the performance of the most effective products identified in this study against chemical warfare agents.

  15. A Polyoxoniobate-Polyoxovanadate Double-Anion Catalyst for Simultaneous Oxidative and Hydrolytic Decontamination of Chemical Warfare Agent Simulants.

    Science.gov (United States)

    Dong, Jing; Hu, Jufang; Chi, Yingnan; Lin, Zhengguo; Zou, Bo; Yang, Song; Hill, Craig L; Hu, Changwen

    2017-04-10

    A novel double-anion complex, H 13 [(CH 3 ) 4 N] 12 [PNb 12 O 40 (V V O) 2 ⋅(V IV 4 O 12 ) 2 ]⋅22 H 2 O (1), based on bicapped polyoxoniobate and tetranuclear polyoxovanadate was synthesized, characterized by routine techniques and used in the catalytic decontamination of chemical warfare agents. Under mild conditions, 1 catalyzes both hydrolysis of the nerve agent simulant, diethyl cyanophosphonate (DECP) and selective oxidation of the sulfur mustard simulant, 2-chloroethyl ethyl sulfide (CEES). In the oxidative decontamination system 100 % CEES was transformed selectively to nontoxic 2-chloroethyl ethyl sulfoxide and vinyl ethyl sulfoxide using nearly stoichiometric 3 % aqueous H 2 O 2 with a turnover frequency (TOF) of 16 000 h -1 . Importantly, the catalytic activity is maintained even after ten recycles and CEES is completely decontaminated in 3 mins without formation of the highly toxic sulfone by-product. A three-step oxidative mechanism is proposed. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Efficacy studies of Reactive Skin Decontamination Lotion, M291 Skin Decontamination Kit, 0.5% bleach, 1% soapy water, and Skin Exposure Reduction Paste Against Chemical Warfare Agents, part 1: guinea pigs challenged with VX.

    Science.gov (United States)

    Braue, Ernest H; Smith, Kelly H; Doxzon, Bryce F; Lumpkin, Horace L; Clarkson, Edward D

    2011-03-01

    This report, first in a series of five, directly compares the efficacy of 4 decontamination products and Skin Exposure Reduction Paste Against Chemical Warfare Agents (SERPACWA) in the haired guinea pig model following exposure to VX. In all experiments, guinea pigs were close-clipped and given anesthesia. In the decontamination experiments, the animals were challenged with VX and decontaminated after a 2-minute delay for the standard procedure or at longer times for the delayed-decontamination experiments. Skin Exposure Reduction Paste Against Chemical Warfare Agents was applied as a thin coating (0.1 mm thick), allowed to dry for 15 minutes, and challenged with VX. After a 2-hour challenge, any remaining VX was blotted off the animal, but no additional decontamination was done. Positive control animals were challenged with VX in the same manner as the treated animals, except that they received no treatment. In addition, the positive control animals were always challenged with 5% VX in isopropyl alcohol (IPA) solution, whereas the treatment animals received either neat (undiluted) VX or 5% VX in IPA solution. All animals were observed during the first 4 hours and again at 24 hours after exposure for signs of toxicity and death. The protective ratio (PR, defined as the median lethal dose [LD(50)] of the treatment group divided by the LD(50) of the untreated positive control animals) was calculated from the probit dose-response curves established for each treatment group and nontreated control animals. Significance in this report was defined as p decontamination experiments, the calculated PRs for Reactive Skin Decontamination Lotion (RSDL), 0.5% bleach, 1% soapy water, and the M291 Skin Decontamination Kit (SDK) were 66, 17, 16, and 1.1, respectively. Reactive Skin Decontamination Lotion was by far the most effective decontamination product tested and was significantly better than any of the other products. Bleach and soapy water provided equivalent and good (PR

  17. Environmental decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Cristy, G.A.; Jernigan, H.C. (eds.)

    1981-02-01

    The record of the proceedings of the workshop on environmental decontamination contains twenty-seven presentations. Emphasis is placed upon soil and surface decontamination, the decommissioning of nuclear facilities, and assessments of instrumentation and equipment used in decontamination. (DLS)

  18. Environmental decontamination

    International Nuclear Information System (INIS)

    Cristy, G.A.; Jernigan, H.C.

    1981-02-01

    The record of the proceedings of the workshop on environmental decontamination contains twenty-seven presentations. Emphasis is placed upon soil and surface decontamination, the decommissioning of nuclear facilities, and assessments of instrumentation and equipment used in decontamination

  19. Genotoxicity testing of extracts from aflatoxin-contaminated peanut meal, following chemical decontamination

    NARCIS (Netherlands)

    Hoogenboom, L.A.P.; Polman, Th.H.G.; Neal, G.E.; Verma, A.; Guyomard, C.; Tulliez, J.; Gautier, J.P.; Coker, R.D.; Nagler, M.J.; Heidenreich, E.; Delort-Laval, J.

    2001-01-01

    One of the most important concerns in the decontamination of aflatoxin-containing feed commodities is the safety of the products for food-producing animals and for human consumption of products derived from these animals. A new method, based on the use of florisil and C18 solid phase extraction

  20. Mass Casualty Decontamination in a Chemical or Radiological/ Nuclear Incident: Further Guiding Principles

    Science.gov (United States)

    Carter, Holly; Amlôt, Richard; Williams, Richard; Rubin, G. James; Drury, John

    2016-01-01

    This short report presents a response to an article written by Cibulsky et al. (2016). The paper by Cibulsky et al. presents a useful and timely overview of the evidence surrounding the technical and operational aspects of mass casualty decontamination. It identifies three priority targets for future research, the third of which is how casualties' needs can be met in ways that best support compliance with and effectiveness of casualty decontamination. While further investigation into behavioural, communication and privacy issues during mass decontamination is warranted, there is now a substantial body of research in this area which is not considered in detail in the succinct summary provided by Cibulsky et al. (2016). In this short report, we summarise the available evidence around likely public behaviour during mass decontamination, effective communication strategies, and potential issues resulting from a lack of privacy. Our intention is to help further focus the research needs in this area and highlight topics on which more research is needed. PMID:27790381

  1. Reduced weight decontamination formulation for neutralization of chemical and biological warfare agents

    Science.gov (United States)

    Tucker, Mark D.

    2014-06-03

    A reduced weight DF-200 decontamination formulation that is stable under high temperature storage conditions. The formulation can be pre-packed as an all-dry (i.e., no water) or nearly-dry (i.e., minimal water) three-part kit, with make-up water (the fourth part) being added later in the field at the point of use.

  2. Lessons Learned from Decontamination Experiences

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, JH

    2000-11-16

    This interim report describes a DOE project currently underway to establish what is known about decontamination of buildings and people and the procedures and protocols used to determine when and how people or buildings are considered ''clean'' following decontamination. To fulfill this objective, the study systematically examined reported decontamination experiences to determine what procedures and protocols are currently employed for decontamination, the timeframe involved to initiate and complete the decontamination process, how the contaminants were identified, the problems encountered during the decontamination process, how response efforts of agencies were coordinated, and the perceived social psychological effects on people who were decontaminated or who participated in the decontamination process. Findings and recommendations from the study are intended to aid decision-making and to improve the basis for determining appropriate decontamination protocols for recovery planners and policy makers for responding to chemical and biological events.

  3. Chemical and Biological Substances Decontamination Study for Mars Missions and Terrestrial Applications

    Science.gov (United States)

    Pottage, Thomas; Walker, James; Bennett, Allan; Vrublevskis, John; Hovland, Scott

    This study, funded by the European Space Agency (ESA) and undertaken by the Health Protec-tion Agency, UK supported by Systems Engineering and Assessment Ltd., was devised to select suitable current decontamination technologies for development for future manned missions to the Moon and Mars. There is a requirement to decontaminate the habitat module due to the concerns about astronaut ill health, microbial deterioration of materials and potential forward contamination in the case of Mars. In the case of the MIR space station, biodeterioration of components and materials occurred, and dangerous levels of airborne microorganisms were detected during air sampling procedures which lead to the introduction of microbial exposure limits (as MORD SSP 50260) to ensure the health of the crew. COSPAR planetary protection guidelines highlight the need to reduce any potential forward or backwards contamination issues that may occur through the use of Extra Vehicular Activity (EVA) suits whilst on Mars. Decontamination of the suit exterior must be completed before any EVA activity on Mars, whilst a further decontamination cycle must be completed after entry to the airlock following EVA. Technologies and techniques have also been investigated for the microbial reduction of the interior surfaces of the EVA suit to stop biodeterioration of the materials and protect the user from pathogenic microbe accumulation. The first work package reviewed the systems description and requirements as detailed in the statement of work. The requirements were broken down into 12 further requirement sections, where they were updated and expanded, resulted in Technical Note (TN) 1 which was then used as the base document for WP2 and WP3. WP2 investigated the current technologies available for the decontamination of the habitat module interior on missions of up to 6 months and missions that have durations of greater than 6 months. A comprehensive review was carried out for the different methods that

  4. Gross decontamination experiment report

    International Nuclear Information System (INIS)

    Mason, R.; Kinney, K.; Dettorre, J.; Gilbert, V.

    1983-07-01

    A Gross Decontamination Experiment was conducted on various levels and surfaces of the TMI - Unit 2 reactor building in March 1982. The polar crane, D-rings, missile shields, refueling canals, refueling bridges, equipment, and elevations 305' and 347'-6'' were flushed with low pressure water. Additionally, floor surfaces on elevation 305' and floor surfaces and major pieces of equipment on elevation 347'-6'' were sprayed with high pressure water. Selective surfaces were decontaminated with a mechanical scrubber and chemicals. Strippable coating was tested and evaluated on equipment and floor surfaces. The effectiveness, efficiency, and safety of several decontamination techniques were established for the large, complex decontamination effort. Various decontamination equipment was evaluated and its effectiveness was documented. Decontamination training and procedures were documented and evaluated, as were the support system and organization for the experiment

  5. Decontamination of radioactive isotopes

    International Nuclear Information System (INIS)

    Despotovic, R.; Music, S.; Subotic, B.; Wolf, R.H.H.

    1979-01-01

    Removal of radioactive isotopes under controlled conditions is determined by a number of physical and chemical properties considered radiocontaminating and by the characteristics of the contaminated object. Determination of quantitative and qualitative factors for equilibrium in a contamination-decontamination system provides the basis for rational and successful decontamination. The decontamination of various ''solid/liquid'' systems is interesting from the scientific and technological point of view. These systems are of great importance in radiation protection (decontamination of various surfaces, liquids, drinking water, fixation or collection of radiocontaminants). Different types of decontamination systems are discussed. The dependence of rate and efficiency of the preparation conditions and on the ageing of the scavenger is described. The influence of coagulating electrolyte on radioactive isotope fixation efficiency was also determined. The fixation of fission radionuclide on oxide scavengers has been studied. The connection between fundamental investigations and practical decontamination of the ''solid/liquid'' systems is discussed. (author)

  6. Gross decontamination experiment report

    Energy Technology Data Exchange (ETDEWEB)

    Mason, R.; Kinney, K.; Dettorre, J.; Gilbert, V.

    1983-07-01

    A Gross Decontamination Experiment was conducted on various levels and surfaces of the TMI - Unit 2 reactor building in March 1982. The polar crane, D-rings, missile shields, refueling canals, refueling bridges, equipment, and elevations 305' and 347'-6'' were flushed with low pressure water. Additionally, floor surfaces on elevation 305' and floor surfaces and major pieces of equipment on elevation 347'-6'' were sprayed with high pressure water. Selective surfaces were decontaminated with a mechanical scrubber and chemicals. Strippable coating was tested and evaluated on equipment and floor surfaces. The effectiveness, efficiency, and safety of several decontamination techniques were established for the large, complex decontamination effort. Various decontamination equipment was evaluated and its effectiveness was documented. Decontamination training and procedures were documented and evaluated, as were the support system and organization for the experiment.

  7. Characterization of ZnS nanoparticles synthesized by co-precipitation method

    International Nuclear Information System (INIS)

    Iranmanesh Parvaneh; Nourzpoor Mohsen; Saeednia Samira

    2015-01-01

    ZnS nanoparticles are prepared by homogeneous chemical co-precipitation method using EDTA as a stabilizer and capping agent. The structural, morphological, and optical properties of as-synthesized nanoparticles are investigated using x-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, ultraviolet-visible (UV-Vis) absorption, and photoluminescence spectroscopy. The x-ray diffraction pattern exhibits a zinc-blended crystal structure at room temperature. The average particle size of the nanoparticles from the scanning electron microscopy image is about 50 nm. The ultraviolet absorption spectrum shows the blue shift in the band gap due to the quantum confinement effect. The photoluminescence spectrum of ZnS nanoparticles shows a blue visible spectrum. (paper)

  8. PWR decontamination feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Silliman, P.L.

    1978-12-18

    The decontamination work which has been accomplished is reviewed and it is concluded that it is worthwhile to investigate further four methods for decontamination for future demonstration. These are: dilute chemical; single stage strong chemical; redox processes; and redox/chemical in combination. Laboratory work is recommended to define the agents and processes for demonstration and to determine the effect of the solvents on PWR materials. The feasibility of Indian Point 1 for decontamination demonstrations is discussed, and it is shown that the system components of Indian Point 1 are well suited for use in demonstrations.

  9. PWR decontamination feasibility study

    International Nuclear Information System (INIS)

    Silliman, P.L.

    1978-01-01

    The decontamination work which has been accomplished is reviewed and it is concluded that it is worthwhile to investigate further four methods for decontamination for future demonstration. These are: dilute chemical; single stage strong chemical; redox processes; and redox/chemical in combination. Laboratory work is recommended to define the agents and processes for demonstration and to determine the effect of the solvents on PWR materials. The feasibility of Indian Point 1 for decontamination demonstrations is discussed, and it is shown that the system components of Indian Point 1 are well suited for use in demonstrations

  10. Studies on the process aspects related to chemical decontamination of chromium-containing alloys with redox processes

    International Nuclear Information System (INIS)

    Kumar, P.S.; Suresh, S.; Chandran, S.; Velmurugan, S.; Narasimhan, S.V.; Rajesh, P.

    2004-01-01

    Presence of chromium in the oxide layer makes oxidative pre-treatment with oxidizing agents such as potassium permanganate (KMnO 4 ) a must for the decontamination of stainless steels and other chromium containing alloys. The effectiveness of pre-treatment with oxidizing reagent varies with the conditions of treatment such as temperature, concentration and whether the medium is acidic or alkaline. A comparative study of the two acidic oxidizing agents, i.e., nitric acid-permanganate and permanganic acid was made. The dissolution behavior of copper and its oxide in permanganic acid was found to be comparable to that of chromium oxide. Citric acid and ascorbic acid were investigated as alternatives to oxalic acid for the reduction/decomposition of permanganate left over after the oxidizing pre-treatment step. It has been established that the reduction of chromate by citric acid is instantaneous only in presence of Mn 2+ ions. It has also been established that reduction of residual permanganate can be achieved with ascorbic acid and with minimum chemical requirement. The capabilities of nitrilotriacetic acid (NTA)-ascorbic acid mixture for the dissolution of hematite have been explored. This study would help to choose the suitable oxidizing agent, the reducing agent used for decomposition of permanganate and to optimize the concentration of reducing formulation so that the process of decontamination is achieved with a minimum requirement of chemicals. The generation of radioactive ion exchange resin as waste is therefore held at a minimum. Ion exchange studies with metal ion complexes of relevance to decontamination were carried out with a view to choose a suitable type of ion exchanger. It has been established that treatment of the ion exchange resin with brine solution can solve the problem of leaching out of non-ionic organics from the resin. (orig.)

  11. Decontamination of chemical warfare sulfur mustard agent simulant by ZnO nanoparticles

    Science.gov (United States)

    Sadeghi, Meysam; Yekta, Sina; Ghaedi, Hamed

    2016-07-01

    In this study, zinc oxide nanoparticles (ZnO NPs) have been surveyed to decontaminate the chloroethyl phenyl sulfide as a sulfur mustard agent simulant. Prior to the reaction, ZnO NPs were successfully prepared through sol-gel method in the absence and presence of polyvinyl alcohol (PVA). PVA was utilized as a capping agent to control the agglomeration of the nanoparticles. The formation, morphology, elemental component, and crystalline size of nanoscale ZnO were certified and characterized by SEM/EDX, XRD, and FT-IR techniques. The decontamination (adsorption and destruction) was tracked by the GC-FID analysis, in which the effects of polarity of the media, such as isopropanol, acetone and n-hexane, reaction time intervals from 1 up to 18 h, and different temperatures, including 25, 35, 45, and 55 °C, on the catalytic/decontaminative capability of the surface of ZnO NPs/PVA were investigated and discussed, respectively. Results demonstrated that maximum decontamination (100 %) occurred in n-hexane solvent at 55 °C after 1 h. On the other hand, the obtained results for the acetone and isopropanol solvents were lower than expected. GC-MS chromatograms confirmed the formation of hydroxyl ethyl phenyl sulfide and phenyl vinyl sulfide as the destruction reaction products. Furthermore, these chromatograms proved the role of hydrolysis and elimination mechanisms on the catalyst considering its surface Bronsted and Lewis acid sites. A non-polar solvent aids material transfer to the reactive surface acid sites without blocking these sites.

  12. Polymer-assisted co-precipitation route for the synthesis of Al 2 O 3

    Indian Academy of Sciences (India)

    It has been observed by field emission scanning electron microscopy analysis that the particle size reduced effectively (below 100 nm) when polymer-assisted co-precipitation route is used instead of the simple co-precipitation technique. A highly dense microstructure of sintered samples has been obtained, driven by ...

  13. Development of decontamination methods

    International Nuclear Information System (INIS)

    Kunze, S.; Dippel, T.; Hentschel, D.

    1976-01-01

    PVC floorings, fabricated by mixing of the basic components, showed no relation between content of fillers and decontamination results. Decontamination results are partly poorer, if the flooring contains a high concentration of the filler, especially if the latter consists mainly of hydrophilic materials. The coloring of the floorings seems to have no influence on the decontamination. Rubber floorings, fabricated by chemical reactions between polymers, vulcanization materials and fillers, show decontamination results depending definitely from the proper choice of the filler. Flooring types, containing lampblack, graphite, kaoline, barium sulfate and titanium oxide are easy to decontaminate. Increasing contents of hydrophilic filler cause a fall off in the decontamination results. The decontamination effectiveness and the homogenity of cleaning pastes based on hydrochloric acid, nitric acid, titanium oxide and polyethylene powders is strongly depended on the content of hydrochloric acid. Reduction of the content of this component to less than 2 w/O remains the effectiveness unchanged only if the titanium oxide-polyethylene powder mixture is substituted by a high density, highly surface active powder material. This type of paste containing no hydrochloric acid shows nearly the same decontamination effectiveness as standard pickling pastes containing about 30% hydrochlorid acid. Properly prepared salt powder turn out to be easily and successfully applied to metal surfaces by a flame spray technique. The thin layer of molten salts is a very effective decontamination to samples contaminated in the primary loop of a PWR. (orig.) [de

  14. Preparation and Heat-Treatment of DWPF Simulants With and Without Co-Precipitated Noble Metals

    International Nuclear Information System (INIS)

    Koopman, David C.:Eibling, Russel E

    2005-01-01

    The Savannah River National Laboratory is in the process of investigating factors suspected of impacting catalytic hydrogen generation in the Chemical Process Cell of the Defense Waste Processing Facility, DWPF. Noble metal catalyzed hydrogen generation in simulation work constrains the allowable acid addition operating window in DWPF. This constraint potentially impacts washing strategies during sludge batch preparation. It can also influence decisions related to the addition of secondary waste streams to a sludge batch. Noble metals have historically been added as trim chemicals to process simulations. The present study investigated the potential conservatism that might be present from adding the catalytic species as trim chemicals to the final sludge simulant versus co-precipitating the noble metals into the insoluble sludge solids matrix. Parallel preparations of two sludge simulants targeting the composition of Sludge Batch 3 were performed in order to evaluate the impact of the form of noble metals. Identical steps were used except that one simulant had dissolved palladium, rhodium, and ruthenium present during the precipitation of the insoluble solids. Noble metals were trimmed into the other stimulant prior to process tests. Portions of both sludge simulants were held at 97 C for about eight hours to qualitatively simulate the effects of long term storage on particle morphology and speciation. The simulants were used as feeds for Sludge Receipt and Adjustment Tank, SRAT, process simulations. The following conclusions were drawn from the simulant preparation work: (1) The first preparation of a waste slurry simulant with co-precipitated noble metals was successful, based on the data obtained. It appears that 99+% of the noble metals were retained in the simulant. (2) Better control of carbonate, hydroxide, and post-wash trim chemical additions is needed before the new method of simulant preparation will be as reproducible as the old method. (3) The two new

  15. Pilot scale study of a chemical treatment process for decontamination of aqueous radioactive waste of pakistan research reactor-1

    International Nuclear Information System (INIS)

    Jan, F.; Hussain, M.; Ahmad, S.S.; Aslam, M.; Haq, E.U.

    2007-12-01

    Chemical treatment process for the low level liquid radioactive waste generated at PINSTECH was previously optimized on lab-scale making use of coprecipitation of hydrous oxides of iron in basic medium. Ferrous sulfate was used as coagulant. Batch wise application of this procedure on pilot scale has been tested on a 1200 L batch volume of typical PINSTECH liquid waste. Different parameters and unit operations have been evaluated. The required data for the construction of a small size treatment plant envisioned can be used for demonstration/teaching purpose as well as for the decontamination of the waste effluents of the Institute. The lab-scale process parameters were verified valid on pilot scale. It was observed that reagent doses can further be economized with out any deterioration of the Decontamination Factors (DF) achieved or of any other aspect of the process. This simple, cost- effective, DF-efficient and time-smart batch wise process could be coupled with an assortment of other treatment operations thus affording universal application. Observations recorded during this study are presented. (author)

  16. Continuum Model for Decontamination of Chemical Warfare Agent from a Rubbery Polymer using the Maxwell-Stefan Formulation

    Science.gov (United States)

    Varady, Mark; Bringuier, Stefan; Pearl, Thomas; Stevenson, Shawn; Mantooth, Brent

    Decontamination of polymers exposed to chemical warfare agents (CWA) often proceeds by application of a liquid solution. Absorption of some decontaminant components proceed concurrently with extraction of the CWA, resulting in multicomponent diffusion in the polymer. In this work, the Maxwell-Stefan equations were used with the Flory-Huggins model of species activity to mathematically describe the transport of two species within a polymer. This model was used to predict the extraction of the nerve agent O-ethyl S-[2(diisopropylamino)ethyl] methylphosphonothioate (VX) from a silicone elastomer into both water and methanol. Comparisons with experimental results show good agreement with minimal fitting of model parameters from pure component uptake data. Reaction of the extracted VX with sodium hydroxide in the liquid-phase was also modeled and used to predict the overall rate of destruction of VX. Although the reaction proceeds more slowly in the methanol-based solution compared to the aqueous solution, the extraction rate is faster due to increasing VX mobility as methanol absorbs into the silicone, resulting in an overall faster rate of VX destruction.

  17. Development of haemostatic decontaminants for the treatment of wounds contaminated with chemical warfare agents. 1: evaluation of in vitro clotting efficacy in the presence of certain contaminants.

    Science.gov (United States)

    Hall, Charlotte A; Lydon, Helen L; Dalton, Christopher H; Chipman, J K; Graham, John S; Chilcott, Robert P

    2015-05-01

    The treatment of penetrating, haemorrhaging injuries sustained within a hazardous environment may be complicated by contamination with toxic chemicals. There are currently no specific medical countermeasures for such injuries. Haemostats with an absorbent mechanism of action have the potential to simultaneously stop bleeding and decontaminate wounds. However, a primary requirement of a 'haemostatic decontaminant' is the retention of clotting function in the presence of chemical contaminants. Thus, the aim of this study was to investigate the haemostatic efficacy of seven commercially available haemostats in the presence of toxic chemicals (soman, VX, sulphur mustard, petrol, aviation fuel and motor oil). Clot viscosity was assessed ex vivo using thrombelastography following treatment of pig blood with: (i) toxic chemical; (ii) haemostat; or (iii) haemostat in combination with toxic chemical. Several contaminants (VX, petrol and GD) were found to be pro-haemostatic and none had an adverse effect on the rate with which the test products attained haemostasis. However, the total clot strength for blood treated with certain haemostats in the presence of sulphur mustard, soman and petrol was significantly decreased. Three test products failed to demonstrate haemostatic function in this ex vivo (thrombelastography) model; this was tentatively ascribed to the products achieving haemostasis through a tamponade mechanism of action, which can only be replicated using in vivo models. Overall, this study has identified a number of commercial products that may have potential as haemostatic decontaminants and warrant further investigation to establish their decontaminant efficacy. Copyright © 2014 John Wiley & Sons, Ltd.

  18. Influence of Decontamination

    International Nuclear Information System (INIS)

    Knaack, Michael

    2016-01-01

    This paper describes the influence of several decontamination techniques on the decommissioning of nuclear facilities. There are different kinds of decontamination methods like mechanical and chemical processes. The techniques specified, and their potential to change measured characteristics like the isotope vector of the contamination is demonstrated. It is common for all these processes, that the contamination is removed from the surface. Slightly adhered nuclides can be removed more effectively than strongly sticking nuclides. Usually a mixture of these nuclides forms the contamination. Problematically any kind of decontamination will influence the nuclide distribution and the isotope vector. On the one hand it is helpful to know the nuclide distribution and the isotope vector for the radiological characterization of the nuclear facility and on the other hand this information will be changed in the decontamination process. This is important especially for free release procedures, radiation protection and waste management. Some questions on the need of decontamination have been discussed. (authors)

  19. Synthesis of Sr- and Mg- doped lanthanum gallate by carbonate co-precipitation

    International Nuclear Information System (INIS)

    Sunitha, Y.; Narasimham, K.V.N.S.V.P.L.; Raju, V.S.; Kumar, Sanjiv

    2010-01-01

    Sr- and Mg- doped lanthanum gallate (LSGM) are promising electrolytes for low temperature solid oxide fuel cells (SOFCs) in view of their high ionic conductivity and stability over a wide range of oxygen partial pressures. LSGM powders are usually prepared by solid-state reactions. However high sintering temperature (∼ 1500 deg C) required for densification and the formation of secondary phases are the major drawbacks of the method. Wet-chemical method is a suitable alternative to solid-state synthesis with the prospect of the realisation of phase pure material with good sinterability at comparatively lower temperatures. In this paper we present the results of our investigation on the synthesis of LaGaO 3 and LSGM by a wet-chemical method through carbonate co-precipitation using ammonium carbonate and ammonium bicarbonate as precipitants. Phase and microstructural evolution of the material have been studied by XRD and SEM respectively, while compositional analysis has been performed by ion beam analysis (IBA) techniques. In addition we have also investigated the incorporation of Sr and Mg in the lattice of LaGaO 3 by (a) solid-state reaction route and (b) wet-chemical approach

  20. Wearable Atmospheric Pressure Plasma Fabrics Produced by Knitting Flexible Wire Electrodes for the Decontamination of Chemical Warfare Agents

    Science.gov (United States)

    Jung, Heesoo; Seo, Jin Ah; Choi, Seungki

    2017-01-01

    One of the key reasons for the limited use of atmospheric pressure plasma (APP) is its inability to treat non-flat, three-dimensional (3D) surface structures, such as electronic devices and the human body, because of the rigid electrode structure required. In this study, a new APP system design—wearable APP (WAPP)—that utilizes a knitting technique to assemble flexible co-axial wire electrodes into a large-area plasma fabric is presented. The WAPP device operates in ambient air with a fully enclosed power electrode and grounded outer electrode. The plasma fabric is flexible and lightweight, and it can be scaled up for larger areas, making it attractive for wearable APP applications. Here, we report the various plasma properties of the WAPP device and successful test results showing the decontamination of toxic chemical warfare agents, namely, mustard (HD), soman (GD), and nerve (VX) agents.

  1. A comparative evaluation of a dipicolinic acid based dilute chemical decontaminant formulation with respect to its efficacy for dissolution of iron oxides

    Energy Technology Data Exchange (ETDEWEB)

    Kamal Kishore; Dey, G.R.; Naik, D.B.; Moorthy, P.N. [Applied Chemistry Division, Bhabha Atomic Research Centre, Mumbai-400 085 (India)

    1998-12-31

    A dilute chemical decontamination formulation containing dipicolinic acid (2,6-pyridine dicarboxylic acid PDCA) and ascorbic acid (AA) has been found to be effective in dissolving magnetite, nickel ferrite and haemetite. Its main advantages arise because of (i) good solubility of the two constituents (ii) lack of absorption on the cation exchanger from acidic media during regenerative decontamination process (iii) stability to ionizing radiation and (iv) low corrosion rate for carbon steel. Dissolution rates of iron oxides in this formulation are as good as or better than in other well known formulations. (author)

  2. New sorption-reagent materials for decontamination of liquid radioactive waste

    International Nuclear Information System (INIS)

    Avramenko, V.A.; Golikov, A.P.; Zheleznov, V.V.; Kaplun, E.V.; Marinin, D.V.; Sokolnitskaya, T.A.

    2001-01-01

    Full text: Use of selective sorbents in liquid radioactive waste (LRW) management is widely spread in the field of nuclear power objects liquid waste decontamination, since the main objective there is to remove long-lived radionuclides of the nuclear cycle. The latter include, first of all, cesium-137, strontium-90, cobalt-60 and a number of α-irradiators. In this case LRW composition for most of the nuclear power objects is rather simple, except acidic deactivation solutions. At the same time, liquid radioactive wastes of different research centers have a variable chemical and radiochemical composition depending on objectives and tasks of a given center research activities. As a result, application of sorption technologies in such waste decontamination determines special requirements to these sorbents selectivity: a wide spectrum of radionuclides that can be removed and fairly high selectivity enabling to remove radionuclides from solutions of complex chemical composition (containing surfactants, complexing agents etc.). This paper is concerned with studying properties of new materials selective to different radionuclides. These materials are capable to interact with solution components whether already contained in the waste or deliberately added into resulting solution. Such sorption-reagent materials combine universal character of co-precipitation methods with simplicity of sorption methods. In this work we studied sorption-reagent inorganic ion-exchange materials interacting with sulfate-, carbonate-, oxalate-, sulfide-, and permanganate-ions. Insoluble compounds formed as a result of this interaction increase tens- and hundreds-fold the sorption selectivity of different radionuclides - strontium, cobalt, mercury, iron, and manganese as compared to conventional ion-exchange system. By means of X-ray phase analysis, IR-spectroscopy, chemical and radiochemical analysis, we have studied the mechanism of radionuclide sorption on different sorption

  3. Gallic acid as a corrosion inhibitor of carbon steel in chemical decontamination formulation

    International Nuclear Information System (INIS)

    Keny, S.J.; Kumbhar, A.G.; Thinaharan, C.; Venkateswaran, G.

    2008-01-01

    Gallic acid (GA) was found to provide corrosion inhibition to carbon steel (CS) at 4.25 mM concentration. Inherent stability to radiation degradation as compared to other reductant and coupled with its anionic nature with respect to removal using ion exchange column makes it suitable for using as both reductant as well as corrosion inhibitor in dilute decontamination formulations operating in the regenerative mode. A formulation containing CA (1.4 mM), EDTA/NTA (1.4 mM), AA (1.0-2.0 mM) and GA (4.25 mM) was found to be more efficient in dissolving hematite and providing 31% corrosion inhibition (passivation) to the CS

  4. Electrolytic technique for the chemical decontamination process with sulfuric acid-cerium (IV) for decommissioning

    International Nuclear Information System (INIS)

    Wei, Tsong-Yang; Hsieh, Jung-Chun.

    1992-01-01

    An electrolyzer with an ion-exchange membrane as the separator has been used to study the electrolytic redox reaction of Ce 4+ / Ce 3+ in sulfuric acid solution, which is a reagent for predismantling system decontamination. Influencing factors such as current density, cerium concentration, acidity, electrolyte flow rate, membrane type and electrode material were studied experimentally. The results indicate that the redox can be achieved with high conversion even as the cerium concentration is below 0.005 M. However, the current efficiency strongly depends on the cerium concentration. In addition, the acid content and the electrolyte flow rate show little influence on the redox reaction. Both cation and anion membrane are feasible for this process. Therefore, the operation conditions are widely applicable. Moreover, two different electrode materials, platinized titanium meshes and graphite, were used. The results show that the platinized titanium meshes is preferable to the graphite for higher current efficiency. (author)

  5. The utilisation of fine sprays for Chemical, Biological, and Radiological or Nuclear (CBRN Decontamination

    Directory of Open Access Journals (Sweden)

    G Nasr

    2016-04-01

    Full Text Available The risk of exposure to hazardous materials, in many industrialenvironments and in everyday life due to the possibility of terrorist attacks,is widely recognised. It is therefore pertinent to have robustdecontamination equipment to limit the effects of hazardous materials andin turn protect human life and assets. This can be done by the applicationof neutralisation (coverage and rinsing techniques to the hazardousmaterials. The overall aim of this paper is to describe an investigationutilising fine sprays for coverage/deposition on the human body, inconjunction with standard safety showers for rinsing of a victim duringdecontamination of CBRN materials. As a novel feature miniature highpressure spill-return atomiser are used. It was found that fine spraysdecrease the consumption of decontamination liquid that is normally usedin practice which has many advantages in practice.

  6. Law of mass action for co-precipitation; Loi d'action de masse de la co-precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Vitorge, P

    2008-07-01

    Coprecipitation is often understood as the incorporation of elements at trace concentrations into -initially pure- solid compounds. Coprecipitation has typically been used to identify radioactive isotopes. Coprecipitation can result in lowering solubility as compared to the solubility, when controlled by pure compounds. For this reason it is also important for geochemistry, waste management and de-pollution studies. The solid obtained with coprecipitation is a new homogeneous solid phase called solid solution. The 2 formula needed to calculate the aqueous solubility when controlled by the ideal AB{sub b(1-x)}C{sub cx} solid solutions are K{sub s,B}{sup 1-x}*K{sub s,C}{sup x} equals [A{sup z{sub A}}]*[B{sup z{sub B}}]{sup b(1-x)}*[C{sup z{sub C}}]{sup cx}/((1-x){sup b(1-x)}x{sup cx}) and K{sub s,C}/K{sub s,B} equals (1-x){sup b}*[C{sup z{sub C}}]{sup c}/[B{sup z{sub B}}]{sup b}*x{sup c}), where K{sub s,B} and K{sub s,C} are the classical constant solubility products of the AB{sub b} and AC{sub c} end-members, the b and c values are calculated from the (z{sub i}) charges of the ions and from charge balance. This report is essentially written to provide a thermodynamic demonstration of the law of mass action in attempts to confirm scientific bases for solubility calculations in geosciences (as typically retention of radio-nuclides by co-precipitation), and to facilitate such calculations. Note that the law of mass action is here a set of 2 equations (not only 1) for the ideal or near ideal systems. Since they are consistent with the phase rule, no extra formula (beside mass balance) is needed to calculate the concentrations of all the species in both phases, namely: [A{sup z{sub A}}], [B{sup z{sub B}}], [C{sup z{sub C}}] and specially x.

  7. Long lasting decontamination foam

    Science.gov (United States)

    Demmer, Ricky L.; Peterman, Dean R.; Tripp, Julia L.; Cooper, David C.; Wright, Karen E.

    2010-12-07

    Compositions and methods for decontaminating surfaces are disclosed. More specifically, compositions and methods for decontamination using a composition capable of generating a long lasting foam are disclosed. Compositions may include a surfactant and gelatin and have a pH of less than about 6. Such compositions may further include affinity-shifting chemicals. Methods may include decontaminating a contaminated surface with a composition or a foam that may include a surfactant and gelatin and have a pH of less than about 6.

  8. Effectiveness of Arsenic Co-Precipitation with Fe-Al Hydroxides for Treatment of Contaminated Water

    Directory of Open Access Journals (Sweden)

    Jaime Wilson Vargas de Mello

    2018-03-01

    Full Text Available ABSTRACT Wastewater treatment is a challenging problem faced by the mining industry, especially when mine effluents include acid mine drainage with elevated arsenic levels. Iron (hydroxides are known to be effective in removal of As from wastewater, and although the resulting compounds are relatively unstable, the presence of structural Al enhances their stability, particularly under reducing conditions. The purpose of this study was to assess the effectiveness of Al-Fe (hydroxide co-precipitates for the removal of As from wastewater and to assess the chemical stability of the products. Different Al-Fe (hydroxides were synthesized at room temperature from ferrous and aluminum salts using three different Fe:Al molar ratios (1:0.0, 1:0.3, and 1:0.7 and aged for 90 days (sulfate experiments or 120 days (chloride experiments in the presence of arsenic. At the end of the aging periods, the precipitated sludges were dried and characterized in order to evaluate their stability and therefore potential As mobility. All treatments were effective in reducing As levels in the water to below 10 µg L-1, but the presence of Al impaired the effectiveness of the treatment. Aluminum decreased the chemical stability of the precipitated sludge and hence its ability to retain As under natural environmental conditions.

  9. Development of Novel Decontamination Techniques for Chemical Agents (GB, VX, HD) Contaminated Facilities. Phase I. Identification and Evaluation of Novel Decontamination Concepts. Volume 1

    Science.gov (United States)

    1983-02-01

    Stamin Methods . .. .. .. .. .. . .. 907 3.8.43 Su ercrit oral Fluorid*e o * * 4 o e o * o o 970 ,•3.8.6.1 Liquid Applications . .. .. .. . .. 107...electrolytic cell . The pas- sage of electric current results in the anodic dissolution of the surface :~-i ~;material and, with proper operating...interconnecting) cells and which have various "skin" thicknesses. The ideal foam for decontamination purposes would have open cells and a * thin skin (or no

  10. Development of new chemical and electrochemical decontamination methods for selected equipment of WWER-440 and WWER-1000 reactor primary circuit

    International Nuclear Information System (INIS)

    Solcanyi, M.; Majersky, D.

    1998-01-01

    Special devices for in-situ application of decontamination technologies assigned for Steam Generator, Pressurizer and Main Circulating Casing of WWER-1000 type were designed, manufactured and tested in real conditions of their use in above Primary Circuit components. New decontamination technologies like low-concentration process NP-NHN for the decontamination of the Steam Generator, combined chemico-mechanical treatment for the Pressurizer and semi-dry electrolysis for the Main Circulating Pump Casing were developed and approved for their safe plant application from point of view of decontamination efficiency, corrosion influence and processing of secondary wastes. Main technological parameters were defined to achieve high decontamination efficiency and corrosion-safe application of all decontamination technologies. (author)

  11. Reduced weight decontamination formulation utilizing a solid peracid compound for neutralization of chemical and biological warfare agents

    Science.gov (United States)

    Tucker, Mark D [Albuquerque, NM

    2011-09-20

    A reduced weight decontamination formulation that utilizes a solid peracid compound (sodium borate peracetate) and a cationic surfactant (dodecyltrimethylammonium chloride) that can be packaged with all water removed. This reduces the packaged weight of the decontamination formulation by .about.80% (as compared to the "all-liquid" DF-200 formulation) and significantly lowers the logistics burden on the warfighter. Water (freshwater or saltwater) is added to the new decontamination formulation at the time of use from a local source.

  12. Thorough Chemical Decontamination with the MEDOC Process : Batch Treatment of Dismantled Pieces or Loop Treatment of Large Components Such as the BR3 Steam Generator and Pressurizer

    International Nuclear Information System (INIS)

    Ponnet, M.; Klein, M.; Massaut, V.; Davain, H.; Aleton, G.

    2003-01-01

    The dismantling of the BR3-PWR reactor leads to the production of large masses of contaminated metallic pieces, including structural materials, primary pipings, tanks and heat exchangers. One of our main objectives is to demonstrate that we can minimize the volume of radioactive waste in an economical way, by the use of alternative waste routes, such as the clearance of materials after thorough decontamination. The SCKoCEN uses its own developed chemical decontamination process, so-called MEDOC (Metal Decontamination by Oxidation with Cerium), based on the use of cerium IV as strong oxidant in sulphuric acid with continuous regeneration using ozone. An industrial installation has been designed and constructed in close collaboration with Framatome-ANP (France). This installation started operation in September 1999 for the treatment of the metallic pieces arising from the dismantling of the BR3 reactor. Since then, more than 25 tons of contaminated material including primary pipes have been treated batchwise with success. 75 % of material could be directly cleared after treatment (Activity lower than 0.1 Bq/g for 60Co) and the other 25% free released after melting activity. The SCKoCEN performed in April 2002 the closed loop decontamination of the BR3 Steam Generator by connection of the MEDOC plant after few adaptations. The decontamination was done within 30 cycles in 3 weeks with consecutive steps like decontamination steps (injection of the solution into the SG) and regeneration steps with ozone. In total, 60 hours of decontamination at 70 C and 130 hours of regeneration were needed to reach the objectives. The tube bundle (600 m2) was attacked and about 10 (micro)m representing more than 41 kg of stainless steel and 2.06 GBq of 60Co was dissolved into the solution. The residual contamination measurements made directly into the water box are still going on, however it seems that the objective to reach the free release criteria after melting is achieved. The next

  13. Large Scale Tests of Vaporous Hydrogen Peroxide (VHP(Register Trademark)) for Chemical and Biological Weapons Decontamination

    National Research Council Canada - National Science Library

    Wagner, George; Procell, Larry; Sorrick, David; Maclver, Brian; Turetsky, Abe; Pfarr, Jerry; Dutt, Diane; Brickhouse, Mark

    2004-01-01

    Vaporous Hydrogen Peroxide (VHP) has been used for more than a decade to sterilize clean rooms and pharmaceutical processing equipment and, more recently, to decontaminate anthraxcontaminated buildings...

  14. Co-precipitation of loperamide hydrochloride and polyethylene glycol using aerosol solvent extraction system

    International Nuclear Information System (INIS)

    Widjojokusumo, Edward; Youn, Yong-Suk; Lee, Youn-Woo; Veriansyah, Bambang; Tjandrawinata, Raymond Rubianto

    2013-01-01

    The co-precipitation of loperamide hydrochloride (LPM) and polyethylene glycol (PEG) using aerosol solvent extraction system (ASES) was examined. Scanning electron microscopy - energy dispersive X-ray spectroscopy (SEM-EDS) analysis showed that the co-precipitation was achieved in various LPM-PEG mass ratios with changes in its morphology. In 10-50% PEG mass ratios, angular-shaped particles were formed, whereas in 65-90% PEG mass ratios, irregular-shaped particles were formed. X-ray diffraction (XRD) analysis of the co-precipitates revealed that the LPM retained amorphous structure, while, on the other hand, the PEG retained crystalline structure. Fourier transform infrared (FT-IR) spectra indicated carbonyl function group of LPM and ether function group of PEG appeared in the co-precipitates. Results of a dissolution test showed that the co-precipitates of LPM-PEG had higher dissolution rate compared to that of the raw material and processed LPM with ASES. Taken together, the co-precipitation of LPMPEG was achieved using ASES and higher in its dissolution rate

  15. Chemical cleaning and decontamination of equipments in Rajasthan Atomic Power Station-2, Kota, NPCIL

    International Nuclear Information System (INIS)

    Pal, P.K.; Saini, S.L.

    2008-01-01

    Heat exchanger of End Shield Cooling System of RAPS-2 made up of 70:30 cupronickel was cleaned with a cleaning solution containing 5% sulphamic acid for periods of around 10 hours at a temperature of 60 deg C. The cleaning was attempted to remove the deposit inside the tube of heat exchanger to make a path of the probe to go inside the tube for eddy current testing for measurement of wall thinning. During the campaign 20 kg of CaCO 3 and 5 kg of SiO 2 were removed. Pre-cooler of heat transport system of RAPS-2 made up of monel was cleaned with a cleaning solution containing 5% citric acid, 1% ascorbic acid and 1% NTA at 50-60 deg C temperature for about 20 hours. The cleaning was attempted to remove the deposit inside the tube of pre cooler to make a path of the probe to go inside the tube for eddy current testing for measurement of wall thinning. For the pre-cooler a decontamination factor of 2 to 3 was obtained. The paper describes about the analysis of the deposit, the cleaning process, and schematic diagram of the process. (author)

  16. Assessment of skin exposure to N,N-dimethylformamide and methyl ethylketone through chemical protective gloves and decontamination of gloves for reuse purposes.

    Science.gov (United States)

    Chao, Keh-Ping; Wang, Ping; Chen, Chen-Peng; Tang, Ping-Yu

    2011-02-15

    N,N-dimethylformamide (DMF) and methyl ethylketone (MEK) are the hazardous chemicals commonly used in the synthetic leather industries. Although chemical protective gloves provide adequate skin exposure protection to workers in these industries, there is currently no clear guideline or understanding with regard to the use duration of these gloves. In this study, the permeation of DMF/MEK mixture through neoprene gloves and the desorption of chemicals from contaminated gloves were conducted using the ASTM F739 cell. The acceptable use duration time of the gloves against DMF/MEK permeation was estimated by assuming a critical body burden of chemical exposure as a result of dermal absorption. In a re-exposure cycle of 5 days, decontamination of the gloves by aeration at 25°C was found to be inadequate in a reduction of breakthrough time as compared to a new unexposed glove. However, decontamination of the gloves by heating at 70 or 100°C showed that the protective coefficient of the exposed gloves had similar levels of resistance to DMF/MEK as that of new gloves. Implications of this study include an understanding of the use duration of neoprene gloves and proper decontamination of chemical protective gloves for reuse. Copyright © 2010 Elsevier B.V. All rights reserved.

  17. Decontamination and Detoxification of Toxic Chemical Warfare Agents Using Polyurethane Sponges

    National Research Council Canada - National Science Library

    Gordon, Richard K; Gunduz, Alper T; Askins, LaTawnya Y; Strating, Simon J; Doctor, Bhupendra P; Clarkson, Edward D; Mitchelree, Larry W; Lukey, Brian; Railer, Roy; Schulz, Susan

    2003-01-01

    .... Another serious problem that may be encountered while caring for personnel contaminated with organophosphorus chemical warfare nerve agents is the possibility that there will be cross-contamination...

  18. Facile Synthesis and Characterization of ZrO₂ Nanoparticles via Modified Co-Precipitation Method.

    Science.gov (United States)

    Ramachandran, M; Subadevi, R; Liu, Wei-Ren; Sivakumar, M

    2018-01-01

    The crystalline Zirconium oxide (ZrO2) nano particles were synthesized using optimized content of Zirconium nitrate (Zr(NO3)2·3H2O) with varying KOH concentration (0.5, 1 and 1.5 M) by co-precipitation method. The thermal history of the precursor was carefully analyzed through Thermogravimetric (TG/DTA) measurement. The as prepared samples were characterized to ensure structural, functional, morphological, compositional, chemical composition and band gap by X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), Laser Raman, scanning electron microscopy (SEM), High resolution Transverse Electron Microscopy (HR-TEM), X-ray photo electron spectroscopy (XPS), EDX, Photo luminescence spectroscopy (PL). The monoclinic structure with space group P21/c has been confirmed from XRD (JCPDS 89-9066). The Zr-O stretching vibration and Zr-O2-Zr bending vibrations were confirmed through FTIR analysis. The well dispersed particles with spherical morphology were confirmed through SEM and TEM analysis. The oxidation states of Zr, O and C were confirmed through XPS analysis. The oxygen vacancies and band gap of the particles were investigated through PL analysis.

  19. Development, evaluation and optimization of superparamagnetite nanoparticles prepared by co-precipitation method.

    Science.gov (United States)

    Montaseri, Hashem; Alipour, Shohreh; Vakilinezhad, Molood Alsadat

    2017-08-01

    Magnetic nanoparticles (MNPs) are of high interest due to their application in medical fields, in particular for theranostics. Specific properties required for such particles include high magnetization, appropriate size and stability. Biocompatible magnetically soft magnetite particles (Fe 3 O 4 ) have been investigated for biological purposes. The intrinsic instability of these nanoparticles and their susceptibility to the oxidization in air, are limitations for their applications. Various methods have been described for synthesis of these nanoparticles among which co-precipitation method is widely experimented. In order to illustrate the synthesis of MNPs elaborately, the effect of different factors on particle formation were studied. The particles morphology, stability, paramagnetic effect, chemical structure and cytotoxicity were evaluated. Particles of 58 and 60 nm obtained by oleic acid coated (OMNPs) and citric acid coated (CMNPs) magnetite nanoparticles respectively. Transmission electron microscopy images exhibited the real sizes are 15 and 13 nm. Magnetic saturations of these nanoparticles were 72 and 68 emu/g which is suitable for medical applications. Both OMNPs and CMNPs were non-toxic to the SK-Br-3 and MCF-7 cells in the concentrations of <2.5 μg/mL. Since these particles exhibit relatively high magnetic saturation, low dose of such material would be required; therefore, these NPs seem to be suitable for theranostics.

  20. Effects of natural organic matter on calcium and phosphorus co-precipitation.

    Science.gov (United States)

    Sindelar, Hugo R; Brown, Mark T; Boyer, Treavor H

    2015-11-01

    Phosphorus (P), calcium (Ca) and natural organic matter (NOM) naturally occur in all aquatic ecosystems. However, excessive P loads can cause eutrophic or hyper-eutrophic conditions in these waters. As a result, P regulation is important for these impaired aquatic systems, and Ca-P co-precipitation is a vital mechanism of natural P removal in many alkaline systems, such as the Florida Everglades. The interaction of P, Ca, and NOM is also an important factor in lime softening and corrosion control, both critical processes of drinking water treatment. Determining the role of NOM in Ca-P co-precipitation is important for identifying mechanisms that may limit P removal in both natural and engineered systems. The main goal of this research is to assess the role of NOM in inhibiting Ca and P co-precipitation by: (1) measuring how Ca, NOM, and P concentrations affect NOM's potential inhibition of co-precipitation; (2) determining the effect of pH; and (3) evaluating the precipitated solids. Results showed that Ca-P co-precipitation occurs at pH 9.5 in the presence of high natural organic matter (NOM) (≈30 mg L(-1)). The supersaturation of calcite overcomes the inhibitory effect of NOM seen at lower pH values. Higher initial P concentrations lead to both higher P precipitation rates and densities of P on the calcite surface. The maximum surface density of co-precipitated P on the precipitated calcite surface increases with increasing NOM levels, suggesting that NOM does prevent the co-precipitation of Ca and P. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Chemical Safety Alert: First Responders’ Environmental Liability Due To Mass Decontamination Runoff

    Science.gov (United States)

    CERCLA's good Samaritan provisions protect responders such as the Chemical Weapons Improved Response Team during lifesaving actions. Once imminent threats are addressed, responders should contain contamination and avoid/mitigate environmental consequences.

  2. Portable Chemical Sterilizer for Microbial Decontamination of Surgical Instruments, Fruits and Vegetables, and Field Feeding Equipment

    National Research Council Canada - National Science Library

    Doona, C. J; Feeherry, F. E; Kustin, K; Curtin, M. A; Baer, D. G

    2006-01-01

    The Portable Chemical Sterilizer (PCS) is a revolutionary biomedical sterilization technology that provides the capability for portable, power-free, point-of-use sterilization to meet the Army's Far-Forward Surgical Teams (FSTs...

  3. Surface decontamination

    International Nuclear Information System (INIS)

    Silva, S. da; Teixeira, M.V.

    1986-06-01

    The general methods of surface decontamination used in laboratory and others nuclear installations areas, as well as the procedures for handling radioactive materials and surfaces of work are presented. Some methods for decontamination of body external parts are mentioned. The medical supervision and assistance are required for internal or external contamination involving or not lesion in persons. From this medical radiation protection decontamination procedures are determined. (M.C.K.) [pt

  4. Gd doping induced weak ferromagnetic ordering in ZnS nanoparticles synthesized by low temperature co-precipitation technique

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Palvinder [Department of Physics, Punjabi University, Patiala, Punjab, 147002 (India); Kumar, Sanjeev, E-mail: sanjeev04101977@gmail.com [Applied Science Department, PEC University of Technology, Chandigarh, 160012 (India); Chen, Chi-Liang, E-mail: chen.cl@nsrrc.org.tw [National Synchrotron Radiation Research Center (NSRRC), Hsinchu, 30076, Taiwan (China); Yang, Kai-Siang [National Synchrotron Radiation Research Center (NSRRC), Hsinchu, 30076, Taiwan (China); Department of Mechanical Engineering, National Taipei University of Technology, Taipei, Taiwan (China); Wei, Da-Hua [Department of Mechanical Engineering, National Taipei University of Technology, Taipei, Taiwan (China); Dong, Chung-Li [Department of Physics, Tamkang University, Tamsui, Taiwan (China); Srivastava, C. [Materials Engineering Department, Indian Institute of Science, Bangalore, 560012 (India); Rao, S.M. [Department of Physics, Punjabi University, Patiala, Punjab, 147002 (India); Institute of Physics, Academia Sinica, Taipei, 11529, Taiwan (China)

    2017-01-15

    Zn{sub 1−x}Gd{sub x}S nanoparticles with Gd concentration x = 0.00, 0.02 and 0.04 were synthesized by the chemical co-precipitation technique using thioglycerol as capping agent. X-ray diffraction (XRD), transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy, X-ray absorption near-edge structure (XANES) and vibrating sample magnetometer (VSM) were employed to characterize the as synthesized Gd doped ZnS nanoparticles. XRD and TEM studies show the formation of cubic ZnS nanoparticles with an average size in the range 5–10 nm. The doping did not alter the phase of the ZnS. The PL spectra of doped ZnS nanoparticles showed the presence of sulphur vacancies in the lattice. XANES of Gd doped ZnS nanoparticles depicts spectral changes may arise from charge transfer between host Zn and dopant Gd ions. A VSM study shows that the weak ferromagnetic behaviour increases with increase in Gd doping ZnS nanoparticles. - Highlights: • Gd doped ZnS nanoparticles synthesized using co-precipitation technique. • PL studies depict sulphur and zinc vacancies in Gd doped ZnS nanoparticles. • XANES studies depict the charge transfer between host Zn and dopant Gd ions. • Room temperature weak ferromagnetism is observed in Gd doped ZnS nanoparticles.

  5. Helix-sense-selective co-precipitation for preparing optically active helical polymer nanoparticles/graphene oxide hybrid nanocomposites.

    Science.gov (United States)

    Huang, Huajun; Li, Weifei; Shi, Yan; Deng, Jianping

    2017-05-25

    Constructing optically active helical polymer based nanomaterials without using expensive and limited chirally helical polymers has become an extremely attractive research topic in both chemical and materials science. In this study, we prepared a series of optically active helical polymer nanoparticles/graphene oxide (OAHPNs/GO) hybrid nanocomposites through an unprecedented strategy-the co-precipitation of optically inactive helical polymers and chirally modified GO. This approach is named helix-sense-selective co-precipitation (HSSCP), in which the chirally modified GO acted as a chiral source for inducing and further stabilizing the predominantly one-handed helicity in the optically inactive helical polymers. SEM and TEM images show quite similar morphologies of all the obtained OAHPNs/GO nanocomposites; specifically, the chirally modified GO sheets were uniformly decorated with spherical polymer nanoparticles. Circular dichroism (CD) and UV-vis absorption spectra confirmed the preferentially induced helicity in the helical polymers and the optical activity of the nanocomposites. The established HSSCP strategy is thus proven to be widely applicable and is expected to produce numerous functional OAHPNs/GO nanocomposites and even the analogues.

  6. Development of Hydrotalcite Based Cobalt Catalyst by Hydrothermal and Co-precipitation Method for Fischer-Tropsch Synthesis

    Directory of Open Access Journals (Sweden)

    Muhammad Faizan Shareef

    2017-10-01

    Full Text Available This paper presents the effect of a synthesis method for cobalt catalyst supported on hydrotalcite material for Fischer-Tropsch synthesis. The hydrotalcite supported cobalt (HT-Co catalysts were synthesized by co-precipitation and hydrothermal method. The prepared catalysts were characterized by using various techniques like BET (Brunauer–Emmett–Teller, SEM (Scanning Electron Microscopy, TGA (Thermal Gravimetric Analysis, XRD (X-ray diffraction spectroscopy, and FTIR (Fourier Transform Infrared Spectroscopy. Fixed bed micro reactor was used to test the catalytic activity of prepared catalysts. The catalytic testing results demonstrated the performance of hydrotalcite based cobalt catalyst in Fischer-Tropsch synthesis with high selectivity for liquid products. The effect of synthesis method on the activity and selectivity of catalyst was also discussed. Copyright © 2017 BCREC Group. All rights reserved Received: 3rd November 2016; Revised: 26th February 2017; Accepted: 9th March 2017; Available online: 27th October 2017; Published regularly: December 2017 How to Cite: Sharif, M.S., Arslan, M., Iqbal, N., Ahmad, N., Noor, T. (2017. Development of Hydrotalcite Based Cobalt Catalyst by Hydrothermal and Co-precipitation Method for Fischer-Tropsch Synthesis. Bulletin of Chemical Reaction Engineering & Catalysis, 12(3: 357-363 (doi:10.9767/bcrec.12.3.762.357-363

  7. Gd doping induced weak ferromagnetic ordering in ZnS nanoparticles synthesized by low temperature co-precipitation technique

    International Nuclear Information System (INIS)

    Kaur, Palvinder; Kumar, Sanjeev; Chen, Chi-Liang; Yang, Kai-Siang; Wei, Da-Hua; Dong, Chung-Li; Srivastava, C.; Rao, S.M.

    2017-01-01

    Zn_1_−_xGd_xS nanoparticles with Gd concentration x = 0.00, 0.02 and 0.04 were synthesized by the chemical co-precipitation technique using thioglycerol as capping agent. X-ray diffraction (XRD), transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy, X-ray absorption near-edge structure (XANES) and vibrating sample magnetometer (VSM) were employed to characterize the as synthesized Gd doped ZnS nanoparticles. XRD and TEM studies show the formation of cubic ZnS nanoparticles with an average size in the range 5–10 nm. The doping did not alter the phase of the ZnS. The PL spectra of doped ZnS nanoparticles showed the presence of sulphur vacancies in the lattice. XANES of Gd doped ZnS nanoparticles depicts spectral changes may arise from charge transfer between host Zn and dopant Gd ions. A VSM study shows that the weak ferromagnetic behaviour increases with increase in Gd doping ZnS nanoparticles. - Highlights: • Gd doped ZnS nanoparticles synthesized using co-precipitation technique. • PL studies depict sulphur and zinc vacancies in Gd doped ZnS nanoparticles. • XANES studies depict the charge transfer between host Zn and dopant Gd ions. • Room temperature weak ferromagnetism is observed in Gd doped ZnS nanoparticles.

  8. Cutaneous challenge with chemical warfare agents in the SKH-1 hairless mouse. (I) Development of a model for screening studies in skin decontamination and protection.

    Science.gov (United States)

    Dorandeu, F; Taysse, L; Boudry, I; Foquin, A; Hérodin, F; Mathieu, J; Daulon, S; Cruz, C; Lallement, G

    2011-06-01

    Exposure to lethal chemical warfare agents (CWAs) is no longer only a military issue due to the terrorist threat. Among the CWAs of concern are the organophosphorus nerve agent O-ethyl-S-(2[di-isopropylamino]ethyl)methyl-phosphonothioate (VX) and the vesicant sulfur mustard (SM). Although efficient means of decontamination are available, most of them lose their efficacy when decontamination is delayed after exposure of the bare skin. Alternatively, CWA skin penetration can be prevented by topical skin protectants. Active research in skin protection and decontamination is thus paramount. In vivo screening of decontaminants or skin protectants is usually time consuming and may be expensive depending on the animal species used. We were thus looking for a suitable, scientifically sound and cost-effective model, which is easy to handle. The euthymic hairless mouse Crl: SKH-1 (hr/hr) BR is widely used in some skin studies and has previously been described to be suitable for some experiments involving SM or SM analogs. To evaluate the response of this species, we studied the consequences of exposing male anaesthetized SKH-1 mice to either liquid VX or to SM, the latter being used in liquid form or as saturated vapours. Long-term effects of SM burn were also evaluated. The model was then used in the companion paper (Taysse et al.(1)).

  9. Environmental Decontamination of a Chemical Warfare Simulant Utilizing a Membrane Vesicle-Encapsulated Phosphotriesterase.

    Science.gov (United States)

    Alves, Nathan J; Moore, Martin; Johnson, Brandy J; Dean, Scott N; Turner, Kendrick B; Medintz, Igor L; Walper, Scott A

    2018-05-09

    While technologies for the remediation of chemical contaminants continue to emerge, growing interest in green technologies has led researchers to explore natural catalytic mechanisms derived from microbial species. One such method, enzymatic degradation, offers an alternative to harsh chemical catalysts and resins. Recombinant enzymes, however, are often too labile or show limited activity when challenged with nonideal environmental conditions that may vary in salinity, pH, or other physical properties. Here, we demonstrate how phosphotriesterase encapsulated in a bacterial outer membrane vesicle can be used to degrade the organophosphate chemical warfare agent (CWA) simulant paraoxon in environmental water samples. We also carried out remediation assays on solid surfaces, including glass, painted metal, and fabric, that were selected as representative materials, which could potentially be contaminated with a CWA.

  10. Chemical dynamics of acidity and heavy metals in a mine water-polluted soil during decontamination using clean water.

    Science.gov (United States)

    Chen, A; Lin, C; Lu, W; Ma, Y; Bai, Y; Chen, H; Li, J

    2010-03-15

    A column leaching experiment was conducted to investigate the chemical dynamics of the percolating water and washed soil during decontamination of an acidic mine water-polluted soil. The results show that leaching of the contaminated soil with clean water rapidly reduced soluble acidity and ion concentrations in the soils. However, only soil column was eliminated after 30 leaching cycles. It is likely that the stored acidity continues to be released to the percolating water over a long period of time. During the column leaching, dissolved Cu and Pb were rapidly leached out, followed by mobilization of colloidal Cu and Pb from the exchangeable and the oxide-bound fractions as a result of reduced ionic strength in the soil solution. The soluble Fe contained in the soil was rare, probably because the soil pH was not sufficiently low; marked mobility of colloidal Fe took place after the ionic strength of the percolating water was weakened and the mobilized Fe was mainly derived from iron oxides. In contrast with Cu, Pb and Fe, the concentration of leachate Zn and Mn showed a continuously decreasing trend during the entire period of the experiment. (c) 2009 Elsevier B.V. All rights reserved.

  11. Broad-Spectrum Liquid- and Gas-Phase Decontamination of Chemical Warfare Agents by One-Dimensional Heteropolyniobates.

    Science.gov (United States)

    Guo, Weiwei; Lv, Hongjin; Sullivan, Kevin P; Gordon, Wesley O; Balboa, Alex; Wagner, George W; Musaev, Djamaladdin G; Bacsa, John; Hill, Craig L

    2016-06-20

    A wide range of chemical warfare agents and their simulants are catalytically decontaminated by a new one-dimensional polymeric polyniobate (P-PONb), K12 [Ti2 O2 ][GeNb12 O40 ]⋅19 H2 O (KGeNb) under mild conditions and in the dark. Uniquely, KGeNb facilitates hydrolysis of nerve agents Sarin (GB) and Soman (GD) (and their less reactive simulants, dimethyl methylphosphonate (DMMP)) as well as mustard (HD) in both liquid and gas phases at ambient temperature and in the absence of neutralizing bases or illumination. Three lines of evidence establish that KGeNb removes DMMP, and thus likely GB/GD, by general base catalysis: a) the k(H2 O)/k(D2 O) solvent isotope effect is 1.4; b) the rate law (hydrolysis at the same pH depends on the amount of P-PONb present); and c) hydroxide is far less active against the above simulants at the same pH than the P-PONbs themselves, a critical control experiment. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Decontamination of chemical-warfare agent simulants by polymer surfaces doped with the singlet oxygen generator zinc octaphenoxyphthalocyanine.

    Science.gov (United States)

    Gephart, Raymond T; Coneski, Peter N; Wynne, James H

    2013-10-23

    Using reactive singlet oxygen (1O2), the oxidation of chemical-warfare agent (CWA) simulants has been demonstrated. The zinc octaphenoxyphthalocyanine (ZnOPPc) complex was demonstrated to be an efficient photosensitizer for converting molecular oxygen (O2) to 1O2 using broad-spectrum light (450-800 nm) from a 250 W halogen lamp. This photosensitization produces 1O2 in solution as well as within polymer matrices. The oxidation of 1-naphthol to naphthoquinone was used to monitor the rate of 1O2 generation in the commercially available polymer film Hydrothane that incorporates ZnOPPc. Using electrospinning, nanofibers of ZnOPPc in Hydrothane and polycarbonate were formed and analyzed for their ability to oxidize demeton-S, a CWA simulant, on the surface of the polymers and were found to have similar reactivity as their corresponding films. The Hydrothane films were then used to oxidize CWA simulants malathion, 2-chloroethyl phenyl sulfide (CEPS), and 2-chloroethyl ethyl sulfide (CEES). Through this oxidation process, the CWA simulants are converted into less toxic compounds, thus decontaminating the surface using only O2 from the air and light.

  13. Formulation of new oxydizing microemulsions for the chemical decontamination of war toxic agents. Activity report. Formulation de nouvelles microemulsions oxydantes pour la decontamination chimique de toxiques de guerre

    Energy Technology Data Exchange (ETDEWEB)

    Eychenne, P.; Rico, I.; Perez, E.

    1994-01-01

    A series of reactions--hydrolysis of para-nitrophenyl diphenyl phosphate (PNDP) and oxydation of sulfurous compounds (tetrahydrothophene and semi-mustard gas)--enabled the authors to simulate the degradation of two particularly harmful war toxic agents: paraoxon and mustard gas. The best decontaminating formulations obtained were the following: (1) Paraoxon degradation: PNDP, 2.51 times 10 to the minus fourth power M; cetyl pyridinium chloride (CPCI), .008 M; K2CO3, .474 M; glycerol/water = 1.7; t(sub 1/2) = 48 sec. (2) Mustard-gas degradation: tetrahydrothiophene oxidation: tetrahydrothiophene, 0,14 M; CPCI, .008 M; magnesium monoperoxyphthalate (MMPP), .075 M; glycerol/water = 1.7; t(sub 1/2) = 102 sec; efficiency = 71%; sulfoxide = 69% sulfone = 31%. -- semi-mustard gas oxydation: semi-mustard gas, .07 M; CPCI, .008 M; MMPP, .075 M; glycerol/water = 1.7; 100% efficiency in 3 minutes.

  14. Toshiba's decontamination technologies for the decommissioning

    International Nuclear Information System (INIS)

    Inoue, Yuki; Yaita, Yumi; Sakai, Hitoshi

    2011-01-01

    For the decommissioning, two types of decontamination process are necessary, 1) system decontamination before dismantling and 2) decontamination of dismantling waste. Toshiba has been developing the decontamination technologies for the both purposes from the viewpoint of minimizing the secondary waste. For the system decontamination before dismantling, chemical decontamination process, such as T-OZON, can be applicable for stainless steel or carbon steel piping. For the decontamination of dismantling waste, several types of process have been developed to apply variety of shapes and materials. For the simple shape materials, physical decontamination process, such as blast decontamination, is effective. We have developed new blast decontamination process with highly durable zirconia particle. It can be used repeatedly and secondary waste can be reduced compared with conventional blast particle. For the complex shape materials, chemical decontamination process can be applied that formic acid decontamination process for carbon steel and electrolytic reduction decontamination process with organic acid for stainless steel. These chemicals can be decomposed to carbon dioxide and water and amount of secondary waste can be small. (author)

  15. From the Decomposition of Chemical Warfare Agents to the Decontamination of Cytostatics

    Czech Academy of Sciences Publication Activity Database

    Štengl, Václav; Šťastný, Martin; Janoš, P.; Mazanec, K.; Perez-Diaz, J. L.; Štenglová Netíková, I. R.

    2018-01-01

    Roč. 57, č. 6 (2018), s. 2114-2122 ISSN 0888-5885 EU Projects: European Commission(XE) 312804 - COUNTERFOG Grant - others:NATO(US) SPS984599 Program:Science for Peace and Security Institutional support: RVO:61388980 Keywords : Chemical warfare agents * Degradation * Metal oxide sorbents Subject RIV: CA - Inorganic Chemistry OBOR OECD: Inorganic and nuclear chemistry Impact factor: 2.843, year: 2016

  16. Evaluation of Silver-Exchanged Zeolites Under Development by University of Maine for Chemical Warfare Agent Decontamination Applications

    National Research Council Canada - National Science Library

    Brickhouse, Mark D; Lalain, Teri A; D'Onofrio, Terrence G; Procell, Lawrence R; Zander, Zachary B

    2007-01-01

    This effort is for the evaluation of a non-toxic photo-catalytic decontamination technology based on silver-exchanged zeolites being developed by the University of Maine research team under the direction of Dr. Howard H...

  17. Structural characterization of chemical warfare agent degradation products in decontamination solutions with proton band-selective (1)H-(31)P NMR spectroscopy.

    Science.gov (United States)

    Koskela, Harri; Hakala, Ullastiina; Vanninen, Paula

    2010-06-15

    Decontamination solutions, which are usually composed of strong alkaline chemicals, are used for efficient detoxification of chemical warfare agents (CWAs). The analysis of CWA degradation products directly in decontamination solutions is challenging due to the nature of the matrix. Furthermore, occasionally an unforeseen degradation pathway can result in degradation products which could be eluded to in standard analyses. Here, we present the results of the application of proton band-selective (1)H-(31)P NMR spectroscopy, i.e., band-selective 1D (1)H-(31)P heteronuclear single quantum coherence (HSQC) and band-selective 2D (1)H-(31)P HSQC-total correlation spectroscopy (TOCSY), for ester side chain characterization of organophosphorus nerve agent degradation products in decontamination solutions. The viability of the approach is demonstrated with a test mixture of typical degradation products of nerve agents sarin, soman, and VX. The proton band-selective (1)H-(31)P NMR spectroscopy is also applied in characterization of unusual degradation products of VX in GDS 2000 solution.

  18. Structural and magnetic properties of cobalt ferrite nanoparticles synthesized by co-precipitation at increasing temperatures

    Science.gov (United States)

    Stein, C. R.; Bezerra, M. T. S.; Holanda, G. H. A.; André-Filho, J.; Morais, P. C.

    2018-05-01

    This study reports on the synthesis and characterization of cobalt ferrite (CoFe2O4) nanoparticles (NPs) synthesized by chemical co-precipitation in alkaline medium at increasing temperatures in the range of 27 °C to 100 °C. High-quality samples in the size range of 5 to 10 nm were produced using very low stirring speed (250 rpm) and moderate alkaline aqueous solution concentration (4.8 mol/L). Three samples were synthesized and characterized by x-ray diffraction (XRD) and room-temperature (RT) magnetization measurements. All samples present superparamagnetic (SPM) behavior at RT and Rietveld refinements confirm the inverse cubic spinel structure (space group Fd-3m (227)) with minor detectable impurity phase. As the synthesis temperature increases, structural parameters such as lattice constant and grain size change monotonically from 8.385 to 8.383 Å and from 5.8 to 7.4 nm, respectively. Likewise, as the synthesis temperature increases the NPs' magnetic moment and saturation magnetization increases monotonically from 2.6 ×103 to 16×103 μB and from 37 to 66 emu/g, respectively. The RT magnetization (M) versus applied field (H) curves were analyzed by the first-order Langevin function averaged out by a lognormal distribution function of magnetic moments. The excellent curve-fitting of the M versus H data is credited to a reduced particle-particle interaction due to both the SPM behavior and the existence of a surface amorphous shell layer (dead layer), the latter reducing systematically as the synthesis temperature increases.

  19. Full system decontamination. AREVAs experience in decontamination prior to decommissioning

    International Nuclear Information System (INIS)

    Topf, Christian

    2010-01-01

    Minimizing collective radiation exposure and producing free-release material are two of the highest priorities in the decommissioning of a Nuclear Power Plant (NPP). Full System Decontamination (FSD) is the most effective measure to reduce source term and remove oxide layer contamination within the plant systems. FSD is typically a decontamination of the primary coolant circuit and the auxiliary systems. In recent years AREVA NP has performed several FSDs in PWRs and BWRs prior to decommissioning by applying the proprietary CORD copyright family and AMDA copyright technology. Chemical Oxidation Reduction Decontamination or CORD represents the chemical decontamination process while AMDA stands for Automated Mobile Decontamination Appliance, AREVA NPs decontamination equipment. Described herein are the excellent results achieved for the FSDs applied at the German PWRs Stade in 2004 and Obrigheim in 2007 and for the FSDs performed at the Swedish BWRs, Barsebaeck Unit 1 in 2007 and Barsebaeck Unit 2 in 2008. All four FSDs were performed using the AREVA NP CORD family decontamination technology in combination with the AREVA NP decontamination equipment, AMDA. (orig.)

  20. Decontamination of TRU glove boxes

    International Nuclear Information System (INIS)

    Crawford, J.H.

    1978-03-01

    Two glove boxes that had been used for work with transuranic nuclides (TRU) for about 12 years were decontaminated in a test program to collect data for developing a decontamination facility for large equipment highly contaminated with alpha emitters. A simple chemical technique consisting of a cycle of water flushes and alkaline permanganate and oxalic acid washes was used for both boxes. The test showed that glove boxes and similar equipment that are grossly contaminated with transuranic nuclides can be decontaminated to the current DIE nonretrievable disposal guide of <10 nCi TRU/g with a moderate amount of decontamination solution and manpower. Decontamination of the first box from an estimated 1.3 Ci to about 5 mCi (6 nCi/g) required 1.3 gallons of decontamination solution and 0.03 man-hour of work for each square foot of surface area. The second box was decontaminated from an estimated 3.4 Ci to about 2.8 mCi (4.2 nCi/g) using 0.9 gallon of decontamination solution and 0.02 man-hour for each square foot of surface area. Further reductions in contamination were achieved by repetitive decontamination cycles, but the effectiveness of the technique decreased sharply after the initial cycle

  1. Magnetic and electrical properties of the La doped Mn-Zn ferrite nanoparticles synthesized by the co-precipitation method

    International Nuclear Information System (INIS)

    Chandel, Vipin; Vijeta; Thakur, Atul; Thakur, Preeti

    2013-01-01

    In the present study, nano crystalline Mn-Zn-La ferrite with chemical formula Mn 0.4 Zn 0.6 La 0.3 Fe 1.7 O 4 was successfully synthesized by a co-precipitation method. The prepared powders were presintered at 700℃. The pallets formed were finally sintered at 700℃, 800℃ and 900℃ for 3h reach. The structural and morphological behavior was investigated by the X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD confirms the formation of the expected spinel structure. Scanning Electron Microscopy (SEM) was used to characterize the microstructure of the ferrite samples i.e. grain morphology, grain size, grain size distribution and shape. Fourier transform infrared spectroscopy (FTIR) confirms the peaks of different molecules in the given sample. Electrical and magnetic properties were studied by using dc resistivity set up and vibrating sample magnetometer (VSM). (author)

  2. Decontamination sheet

    International Nuclear Information System (INIS)

    Hirose, Emiko; Kanesaki, Ken.

    1995-01-01

    The decontamination sheet of the present invention is formed by applying an adhesive on one surface of a polymer sheet and releasably appending a plurality of curing sheets. In addition, perforated lines are formed on the sheet, and a decontaminating agent is incorporated in the adhesive. This can reduce the number of curing operation steps when a plurality steps of operations for radiation decontamination equipments are performed, and further, the amount of wastes of the cured sheets, and operator's exposure are reduced, as well as an efficiency of the curing operation can be improved, and propagation of contamination can be prevented. (T.M.)

  3. and aluminum-substituted cobalt ferrite prepared by co-precipitation

    Indian Academy of Sciences (India)

    Structural and magnetic properties of zinc- and aluminum-substituted cobalt ferrite prepared by co-precipitation method. S T ALONE1,∗ and K M JADHAV2. 1Shiv Chhatrapati College, Aurangabad 431 004, India. 2Department of Physics, Dr. B. A. Marathwada University, Aurangabad 431 004, India. ∗Corresponding author.

  4. Chemical surety material decontamination and decommissioning of Los Alamos National Laboratory Chemical Surety Material Laboratory area TA-3, building SM-29, room 4009

    International Nuclear Information System (INIS)

    Moore, T.E.; Smith, J.M.

    1994-04-01

    From 1982 through 1987, Los Alamos National Laboratory (LANL) performed surety laboratory operations for the U.S. Army Medical Research and Development Command (MRDC). Room 4009 in building SM-29, TA-3, was used as the laboratory for work with the following chemical surety material (CSM) agents: sarin (GB), soman (GD), lewisite (L), and distilled mustard (HD) radio-labelled with H 3 or C 14 . The work was confined to three CSM-certified fume hoods, located in room 4009 (see diagram in Appendix C). The laboratory ceased all active operations during the late 1986 and early 1987 period. From 1987 until 1993 the laboratory was secured and the ventilation system continued to operate. During late 1992, the decision was made to utilize this laboratory space for other operations, thus a decision was made to dismantle and reconfigure this room. LANL sub-contracted Battelle Memorial Institute (BMI) to draw upon the CSM experience of the technical staff from the Hazardous Materials Research Facility (HMRF) to assist in developing a decontamination and decommissioning plan. BMI was subcontracted to devise a CSM safety training course, and a sampling and air monitoring plan for CSM material to ensure personnel safety during all disassembly operations. LANL subcontracted Johnson Controls personnel to perform all disassembly operations. Beginning in early 1993 BMI personnel from the HMRF visited the laboratory to develop both the safety plan and the sample and air monitoring plan. Execution of that plan began in September 1993 and was completed in January 1994

  5. Decontamination method

    International Nuclear Information System (INIS)

    Tsujimura, Hiroshi; Ono, Shigeki; Tada, Nobuo; Tamai, Yasumasa; Okada, Masaya; Kurihara, Masayuki; Onuki, Toyomitsu; Toyota, Seiichi

    1998-01-01

    Before contamination of materials to be decontaminated, a surface of a region where a strippable paint is to be coated is smoothed by an epoxy resin previously. Then, a waterproof sheet is extended to the material to be decontaminated, and the strippable paint is applied to the periphery or the entire surface of the sheet. In order to facilitate peeling, the strippable paint is not applied to a portion of the outer circumference of the sheet. Even if the contaminating circumstance is an air atmosphere or a liquid such as reactor water, since the sheet itself has waterproofness and the strippable paint excellent in gas and water tightness is applied to the periphery, contamination is eliminated. When decontaminating the material to be decontaminated having contaminated surfaces, if the sheet for the start of peeling is picked up and the sheet is peeled, the strippable paint at the periphery thereof can be peeled off together with the sheet. (N.H.)

  6. Decontamination method

    Energy Technology Data Exchange (ETDEWEB)

    Tsujimura, Hiroshi; Ono, Shigeki; Tada, Nobuo; Tamai, Yasumasa; Okada, Masaya; Kurihara, Masayuki [Hitachi Ltd., Tokyo (Japan); Onuki, Toyomitsu; Toyota, Seiichi

    1998-10-27

    Before contamination of materials to be decontaminated, a surface of a region where a strippable paint is to be coated is smoothed by an epoxy resin previously. Then, a waterproof sheet is extended to the material to be decontaminated, and the strippable paint is applied to the periphery or the entire surface of the sheet. In order to facilitate peeling, the strippable paint is not applied to a portion of the outer circumference of the sheet. Even if the contaminating circumstance is an air atmosphere or a liquid such as reactor water, since the sheet itself has waterproofness and the strippable paint excellent in gas and water tightness is applied to the periphery, contamination is eliminated. When decontaminating the material to be decontaminated having contaminated surfaces, if the sheet for the start of peeling is picked up and the sheet is peeled, the strippable paint at the periphery thereof can be peeled off together with the sheet. (N.H.)

  7. Chemical decontamination of process equipment using recyclable chelating solvent Phase I. Final report, September 1993--June 1995

    International Nuclear Information System (INIS)

    1995-10-01

    The Department of Energy (DOE) is now faced with the task of meeting decontamination and decommissioning obligations at numerous facilities by the year 2019. Due to the tremendous volume of material involved, innovative decontamination technologies are being sought that can reduce the volumes of contaminated waste materials and secondary wastes requiring disposal. With sufficient decontamination, some of the material from DOE facilities could be released as scrap into the commercial sector for recycle, thereby reducing the volume of radioactive waste requiring disposal. Although recycling may initially prove to be more costly than current disposal practices, rapidly increasing disposal costs are expected to make recycling more and more cost effective. Additionally, recycling is now perceived as the ethical choice in a world where the consequences of replacing resources and throwing away reusable materials are impacting the well-being of the environment

  8. Microbial decontamination by low dose gamma irradiation and its impact on the physico-chemical quality of peppermint (Mentha piperita)

    International Nuclear Information System (INIS)

    Machhour, Hasna; El Hadrami, Ismail; Imziln, Boujamaa; Mouhib, Mohamed; Mahrouz, Mostafa

    2011-01-01

    Peppermint was inoculated with Escherichia coli and its decontamination was carried out by gamma irradiation at low irradiation doses (0.5, 1.0 and 2.66 kGy). The efficiency of this decontamination method was evaluated and its impact on the quality parameters of peppermint, such as the color and ash content, as well as the effect on fingerprint components such as phenols and essential oils, was studied. Gas chromatography coupled to mass spectrometry (GC/MS) and High Performance Liquid Chromatography (HPLC) were used to characterize essential oils and phenolic compounds, respectively. The results indicated a complete decontamination of peppermint after the low dose gamma irradiation without a significant loss in quality attributes.

  9. Presolidification treatment of decontamination wastes

    International Nuclear Information System (INIS)

    Habayeb, M.A.

    1982-02-01

    Unsatisfactory leaching performance of several solidified decontamination solutions indicated a need for presolidification treatments to reduce the water sensitivity of the active chemicals. Chemical treatments examined in this work include pH adjustment, precipitation and oxidation-reduction reactions. The reactions involved in these treatments are discussed. The most suitable presolidification treatment for each decontamination solution has been identified. Further research is needed to test the effectivenss of these treatments

  10. Skin decontamination

    International Nuclear Information System (INIS)

    Moehrle, G.

    1975-01-01

    A general survey of skin decontamination is given. The success of every decontamination treatments depends mainly on the speed, but also on the care, with which the action is taken. The best way to remove the skin contaminants is thorough washing under lukewarm running water with mild soap and a soft brush. This washing is to be repeated several times for a period of several minutes. If results are not satisfactory, light duty detergents and wetting agents available commercially may also be used. Some solutions which have proved useful are mentioned. The decontamination solutions are best used in the order given. When one has no satisfactory decontamination effect, the next one is to be used. If necessary, these agents must be used several times in the stated order as long as this does not involve too much strain for the skin. All the decontamination measures mentioned refer, of course, to intact healthy skin. After decontamination has been completed, the skin should be treated with a protective cream

  11. Radioactive decontamination of equipment

    International Nuclear Information System (INIS)

    1982-03-01

    After a recall of some definitions relating to decontamination techniques and of the regulation into effect, the principles to be respected to arrange rationally work zones are quoted while insisting more particularly on the types of coatings which facilitate maintenance operations and the dismantling of these installations. Then, the processes and equipments to use in decontamination units for routine or particular operations are described; the list of recommended chemical products to decontaminate the equipment is given. The influence of these treatments on the state and the duration of life of equipments is studied, and some perfectible methods are quoted. In the appendix, are given: the limits of surface contamination accepted in the centers; a standard project which defines the criteria of admissible residual contamination in wastes considered as cold wastes; some remarks on the interest that certain special ventilation and air curtain devices for the protection of operators working on apparatus generating contaminated dusts [fr

  12. Decontamination processes for waste glass canisters

    International Nuclear Information System (INIS)

    Rankin, W.N.

    1981-06-01

    The process which will be used to decontaminate waste glass canisters at the Savannah River Plant consists of: decontamination (slurry blasting); rinse (high-pressure water); and spot decontamination (high-pressure water plus slurry). No additional waste will be produced by this process because glass frit used in decontamination will be mixed with the radioactive waste and fed into the glass melter. Decontamination of waste glass canisters with chemical and abrasive blasting techniques was investigated. The ability of a chemical technique with HNO 3 -HF and H 2 C 2 O 4 to remove baked-on contamination was demonstrated. A correlation between oxide removal and decontamination was observed. Oxide removal and, thus, decontamination by abrasive blasting techniques with glass frit as the abrasive was proposed and demonstrated

  13. Decontamination processes for waste glass canisters

    International Nuclear Information System (INIS)

    Rankin, W.N.

    1981-01-01

    The process which will be used to decontaminate waste glass canisters at the Savannah River Plant consists of: decontamination (slurry blasting); rinse (high-pressure water); and spot decontamination (high-pressure water plus slurry). No additional waste will be produced by this process because glass frit used in decontamination will be mixed with the radioactive waste and fed into the glass melter. Decontamination of waste glass canisters with chemical and abrasive blasting techniques was investigated. The ability of a chemical technique with HNO 3 -HF and H 2 C 2 O 4 to remove baked-on contamination was demonstrated. A correlation between oxide removal and decontamination was observed. Oxide removal and, thus, decontamination by abrasive blasting techniques with glass frit as the abrasive was proposed and demonstrated

  14. Comparison of the properties of simulated synroc synthesized by sol-gel and a novel co - precipitation method

    International Nuclear Information System (INIS)

    Potdar, H.S.; Vijayanand, S.; Khaja Mohaideen, K.; Joy, P.A.; Raja Madhavan, R.; Kutty, K.V.G.; Ambashta, R.D.; Wattal, P.K.

    2009-01-01

    Synroc is a multiphase dense titanate based ceramic designed for the incorporation of high-level waste (HLW) from the reprocessing of spent nuclear fuel. Synroc or synthetic rock consists of four main titanate phases - zirconolite (CaZrTi 2 O 7 ), hollandite (BaAlO 2 Ti 6 O 16 ), perovskite (CaTiO 3 ) and rutile (TiO 2 ), with the matrix composition as shown in Table 1. It is known that these phases have the capacity to incorporate most of the elements into their crystal structures which are present in the HLW derived from the reprocessing of spent nuclear fuel from power reactors. Synroc is considered as the most effective and durable means of immobilising various forms of high-level radioactive wastes for disposal. Synroc is also considered as a low-risk, tailored waste form, offering higher waste loading and over all cost savings. Simulated synroc precursor powders are typically produced by advanced wet chemical methods such as alkoxide hydrolysis and sol-gel routes. These routes were developed to produce powders with well defined physical and chemical characteristics such as correct chemical composition, high degree of homogeneity, reactivity and readily densifiable material to 99% of theoretical density during hot isostatic pressing. However, the reported alkoxide hydrolysis and hydroxide routes suffer from several disadvantages such as use of large quantities of organic solvents and their disposal as effluent, difficulty in maintaining exact chemical composition, use of costly alkoxide precursors which are moisture sensitive and require critical processing conditions to control their rate of hydrolysis, etc. In the present work we report a comparative study the characteristics of synroc-C (14% waste loading) powders and sintered pellets synthesized by the known alkoxide hydrolysis method and a simple chemical co-precipitation route developed by us. The advantages of the co-precipitation route are its simplicity, ease of handling and utilization of cheaper raw

  15. Electrochemical performance of multi-element doped α-nickel hydroxide prepared by supersonic co-precipitation method

    International Nuclear Information System (INIS)

    Zhang, Z.J.; Zhu, Y.J.; Bao, J.; Lin, X.R.; Zheng, H.Z.

    2011-01-01

    Highlights: → The α-nickel hydroxides doped with several elements were prepared by supersonic co-precipitation method. → Cyclic voltammetry and electrochemical impedance spectroscopy show sample C has the best electrochemical performance. → The charge/discharge tests show that the 0.5 C discharge capacity (346 mAh/g) of sample C is even larger than that (337 mAh/g) at 0.1 C rate, while the discharge capacity at 0.5 C rate is much lower than that at 0.1 C rate for samples A and B. - Abstract: The multi-element doped α-nickel hydroxides have been prepared by supersonic co-precipitation method. Three kinds of samples A, B, C were prepared by chemically coprecipitating Ni, Al, Co, Y, Zn. It was found that sample C produced better performance than the others. The cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements indicated that sample C has better electrochemical performance, such as better reaction reversibility, higher proton diffusion coefficient and lower charge-transfer resistance, than those of samples A and B. The charge-discharge tests showed that the discharge capacity (346 mA h/g) of sample C is even larger at 0.5 C rate than that (337mAh/g) at 0.1 C rate, while the discharge capacity at 0.5 C rate is much lower than that at 0.1 C rate for samples A and B. It indicates that all doped elements can produce the synergic effect and further improve the electrochemical properties of the active materials.

  16. Chemical decontamination method

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Susumu; Ikehara, Fumiaki; Miyazaki, Atsuo

    1994-04-12

    Pipelines and equipments deposited with cruds undergo an oxidative dissolving treatment by a cleaning liquid using persulfuric acid and persulfate. Then a reducing agent is added to cleaning liquid wastes by an excess amount than required for decomposing and reducing the remaining persulfuric acid and persulfate. As the reducing agent, one or more of materials selected from ascorbic acid, erythorbic acid, oxalic acid, salts and derivatives thereof are used. Further, if required, sulfuric acid or sulfuric acid is also added. This can effectively dissolve even less soluble cruds to shorten the processing time, thereby reducing the operators' exposure dose and attaining devoluming of the wastes. (T.M.).

  17. Chemical decontamination method

    International Nuclear Information System (INIS)

    Inoue, Susumu; Ikehara, Fumiaki; Miyazaki, Atsuo.

    1994-01-01

    Pipelines and equipments deposited with cruds undergo an oxidative dissolving treatment by a cleaning liquid using persulfuric acid and persulfate. Then a reducing agent is added to cleaning liquid wastes by an excess amount than required for decomposing and reducing the remaining persulfuric acid and persulfate. As the reducing agent, one or more of materials selected from ascorbic acid, erythorbic acid, oxalic acid, salts and derivatives thereof are used. Further, if required, sulfuric acid or sulfuric acid is also added. This can effectively dissolve even less soluble cruds to shorten the processing time, thereby reducing the operators' exposure dose and attaining devoluming of the wastes. (T.M.)

  18. Formerly utilized MED/AEC sites Remedial Action Program. Report of the decontamination of Jones Chemical Laboratory, Ryerson Physical Laboratory, and Eckhart Hall, the University of Chicago, Chicago, Illinois

    International Nuclear Information System (INIS)

    Wynuveen, R.A.; Smith, W.H.; Sholeen, C.M.; Flynn, K.F.

    1984-08-01

    The US Department of Energy (DOE) has implemented a program to decontaminate radioactively contaminated sites that were formerly utilized by the Manhattan Engineer District (MED) and/or the Atomic Energy Commission (AEC) for activities that included handling of radioactive material. This program is referred to as the ''Formerly Utilized Sites Remedial Action Program'' (FUSRAP). Among these sites are Jones Chemical Laboratory, Ryerson Physical Laboratory, Kent Chemical Laboratory, and Eckhart Hall of The University of Chicago, Chicago, Illinois. Since 1977, the University of Chicago decontaminated Kent Chemical Laboratory as part of a facilities renovation program. All areas of Eckhart Hall, Ryerson Physical Laboratory, and Jones Chemical Laboratory that had been identified as contaminated in excess of current guidelines in the 1976-1977 surveys were decontaminated to levels where no contamination could be detected relative to natural backgrounds. All areas that required defacing to achieve this goal were restored to their original condition. The radiological evaluation of the sewer system, based primarily on the radiochemical analyses of sludge and water samples, indicated that the entire sewer system is potentially contaminated. While this evaluation was defined as part of this project, the decontamination of the sewer system was not included in the purview of this effort. The documentation included in this report substantiates the judgment that all contaminated areas identified in the earlier reports in the three structures included in the decontamination effort (Eckhart Hall, Ryerson Physical Laboratory, and Jones Chemical Laboratory) were cleaned to levels commensurate with release for unrestricted use

  19. Tests for improvement of decontamination factors on RWTP technological line of precipitation

    International Nuclear Information System (INIS)

    Popovici, C.

    1998-01-01

    Low and intermediate level radioactive wastes are produced from diverse applications of radionuclides and radioactive materials in industry, medicine, agriculture and research. Many of the liquid wastes need treatment for safe management. Chemical precipitation process is well established for the removal of radioactive from LLW and ILW. The precipitation of insoluble compounds is one of the oldest and most used process for the treatment of aqueous waste. The precipitation can be performed either in a simple step or by combined chemical treatment which mainly includes as radioactive carries iron oxo-hydroxides, iron phosphate, calcium phosphate and cooper ferrocyanide. The contaminants are removed from LLW and ILW during precipitation by different mechanisms such as: coagulation and flocculation process, precipitation and co-precipitation, adsorption on the coagulant aid, ion exchange and physical enmeshment by coagulant aid. All these processes are directly dependent on the precipitate properties and its structure which are connected with the initial system composition and the precipitation procedure. Chemical precipitation method for treatment of LLW and ILW by co-precipitation of caesium with cooper ferrocyanide was employed on the real radioactive wastes where the volumes were 3 m 3 , 24 m 3 and 30 m 3 . The percentage removals of Cs-137 from 2285 Bq, 1310 Bq and 1232 Bq per litre of real effluents were 98.8%, 98.9% and 99.1%, respectively. Test runs for removal of Cs-137 from the wastes varied from 90% to 95%. High decontamination factors were observed in the pH range of 9 to 10.5. (author)

  20. Chemical surety material decontamination and decommissioning of Los Alamos National Laboratory Chemical Surety Material Laboratory area TA-3, building SM-29, room 4009

    Energy Technology Data Exchange (ETDEWEB)

    Moore, T.E.; Smith, J.M.

    1994-04-01

    From 1982 through 1987, Los Alamos National Laboratory (LANL) performed surety laboratory operations for the U.S. Army Medical Research and Development Command (MRDC). Room 4009 in building SM-29, TA-3, was used as the laboratory for work with the following chemical surety material (CSM) agents: sarin (GB), soman (GD), lewisite (L), and distilled mustard (HD) radio-labelled with H{sup 3} or C{sup 14}. The work was confined to three CSM-certified fume hoods, located in room 4009 (see diagram in Appendix C). The laboratory ceased all active operations during the late 1986 and early 1987 period. From 1987 until 1993 the laboratory was secured and the ventilation system continued to operate. During late 1992, the decision was made to utilize this laboratory space for other operations, thus a decision was made to dismantle and reconfigure this room. LANL sub-contracted Battelle Memorial Institute (BMI) to draw upon the CSM experience of the technical staff from the Hazardous Materials Research Facility (HMRF) to assist in developing a decontamination and decommissioning plan. BMI was subcontracted to devise a CSM safety training course, and a sampling and air monitoring plan for CSM material to ensure personnel safety during all disassembly operations. LANL subcontracted Johnson Controls personnel to perform all disassembly operations. Beginning in early 1993 BMI personnel from the HMRF visited the laboratory to develop both the safety plan and the sample and air monitoring plan. Execution of that plan began in September 1993 and was completed in January 1994.

  1. Magnetite nanoparticles prepared by co-precipitation method in different conditions

    Energy Technology Data Exchange (ETDEWEB)

    Aphesteguy, J.C., E-mail: caphestegu@fi.uba.ar [LAFMACEL-INTECIN, Facultad de Ingeniería, UBA, Paseo Colón 850, C1063EHA Buenos Aires (Argentina); Kurlyandskaya, G.V. [Universidad del País Vasco UPV-EHU, Dept. Electricidad y Electronica, 48940 Leioa (Spain); Ural Federal University, Dept. Magnetism and Magnetic Nanomaterials, 620000 Ekaterinburg (Russian Federation); Celis, J.P. de [National Technology University (UTN), Facultad Regional Avellaneda, Department of Chemistry (Argentina); Safronov, A.P. [Ural Federal University, Dept. Magnetism and Magnetic Nanomaterials, 620000 Ekaterinburg (Russian Federation); Institute of Electrophysics UD RAS, Ekaterinburg 620016 (Russian Federation); Schegoleva, N.N. [Institute of Metal Physics UD RAS, Ekaterinburg 620044 (Russian Federation)

    2015-07-01

    Magnetic nanoparticles (MNPs) of pure magnetite (Fe{sub 3}O{sub 4}) were prepared in an aqueous solution (sample M−I) and in a water-ethyl alcohol mixture (sample M−II) by the co-precipitation method. The structure and magnetic properties of both samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), magnetic (M−H) and microwave measurements (FMR). The mean average particle diameter and particle size distribution was evaluated by the Dynamic Light Scattering (DLS) and Brunauer- Emmett-Teller techniques (BET). The Quantitative chemical analysis of iron was performed by Inductively Coupled Plasma (ICP)- Atomic Emission Spectroscopy (AES) technique. The MNPs prepared in aqueous solution show a higher grain than those prepared in the water-ethyl alcohol mixture. The type of phase structure in both cases can be defined as “defective spinel”. The shape of the majority of M−I MNPs is octahedral. The shape of the majority of M−II MNPs is cubic. The specific surface area of MNPs was as high as 14.4 m{sup 2}/g for M−I sample and 77.8 m{sup 2}/g for sample M–II. The obtained saturation magnetization values of 75 emu/g (M−I) and 68 emu/g (M−II) are consistent with expected values for magnetite MNPs of observed sizes. Ferromagnetic resonance (FMR) measurements confirmed that MNPs of both types are magnetically homogeneous materials. FMR lines' position and line widths can be understood by invoking the local dipolar fields, deviations from sphericity, magnetocrystalline anisotropy and stresses. M−I sample shows sizeable zero field microwave absorption which is absent in the M−II case. The differences in microwave behaviour of M−I and M−II MNPs can be used in the design of microwave radiation absorbing multilayers. - Highlights: • Magnetite nanoparticles were prepared in two different conditions. • Specific surface area of sample prepared in water- ethanol mix is

  2. Optimisation of parameters for co-precipitation of uranium and plutonium - results of simulation studies

    International Nuclear Information System (INIS)

    Pandey, N.K.; Velvandan, P.V.; Murugesan, S.; Ahmed, M.K.; Koganti, S.B.

    1999-01-01

    Preparation of plutonium oxide from plutonium nitrate solution generally proceeds via oxalate precipitation route. In a nuclear fuel reprocessing scheme this step succeeds the partitioning step (separation of uranium and plutonium). Results of present studies confirm that it is possible to avoid partitioning step and recover plutonium and uranium as co-precipitated product. This also helps in minimising the risk of proliferation of fissile material. In this procedure, the solubility of uranium oxalate in nitric acid is effectively used. Co-precipitation parameters are optimised with simulated solutions of uranium nitrate and thorium nitrate (in place of plutonium). On the basis of obtained results a reconversion flow-sheet is designed and reported here. (author)

  3. Co-precipitation and solubility studies of cesium, potassium and sodium tetraphenylborate

    International Nuclear Information System (INIS)

    Peterson, R.A.

    1999-01-01

    This report contains the results from a study requested by High Level Waste Division on the co-precipitation and solubility of cesium, potassium, and sodium tetraphenylborate. Co-precipitation of cesium (Cs), potassium (K), and sodium (Na) tetraphenylborate (TPB) helps determine the efficiency of reagent usage in the Small Tank Precipitation Process. This process uses NaTPB to remove cesium from waste by means of precipitation. Previous studies by McCabe suggested that if the sodium ion concentration [Na+] increased the rate at which cesium tetraphenylborate (KTPB) in the presence of high [Na+] (∼5M) appears to produce a mixed solid phase composed of NaTPB and KTPB together in the crystal lattice

  4. Application of the chemical properties of ruthenium to decontamination processes; L'application des proprietes chimiques du ruthenium a des procedes de decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Fontaine, A.; Berger, D. [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

    1965-07-01

    The chemical properties of ruthenium in the form of an aqueous solution of the nitrate and of organic tributylphosphate solution are reviewed. From this data, some known examples are given: they demonstrate the processes of separation or of elimination of ruthenium from radioactive waste. (authors) [French] Les proprietes chimiques du ruthenium en solutions aqueuses nitriques et en solutions organiques de tributylphosphate, sont passees en revue. A partir de ces donnees, quelques exemples connus sont cites: ils exposent des procedes de separation ou d'elimination du ruthenium de dechets radioactifs. (auteurs)

  5. Application of the chemical properties of ruthenium to decontamination processes; L'application des proprietes chimiques du ruthenium a des procedes de decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Fontaine, A; Berger, D [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

    1965-07-01

    The chemical properties of ruthenium in the form of an aqueous solution of the nitrate and of organic tributylphosphate solution are reviewed. From this data, some known examples are given: they demonstrate the processes of separation or of elimination of ruthenium from radioactive waste. (authors) [French] Les proprietes chimiques du ruthenium en solutions aqueuses nitriques et en solutions organiques de tributylphosphate, sont passees en revue. A partir de ces donnees, quelques exemples connus sont cites: ils exposent des procedes de separation ou d'elimination du ruthenium de dechets radioactifs. (auteurs)

  6. 228Ra and 226Ra measurement on a BaSO4 co-precipitation source

    International Nuclear Information System (INIS)

    Medley, Peter; Martin, Paul; Bollhöfer, Andreas; Parry, David

    2015-01-01

    One of the most commonly-used methods for determination of 226 Ra, particularly in water samples, utilises co-precipitation of Ra with BaSO 4 , followed by microfiltration to produce a source for alpha counting. This paper describes two extensions to BaSO 4 co-precipitation methods which enable determination of 228 Ra using the same source. The adaptations presented here do not introduce any contaminants that will affect the separation of radium or alpha counting for 226 Ra, and can be used for re-analysis of already existing sources prepared by BaSO 4 co-precipitation. The first adaptation uses detection of 228 Ac on the source by gamma spectrometry. The detection efficiency is high, allowing analysis of water samples at sufficiently low activity to be suitable in testing for compliance with drinking water quality standards. As 228 Ac grows in quickly, taking less than 2 days to reach equilibrium with the 228 Ra parent, this can also be useful in radiological emergency response situations. The second adaptation incorporates a method for the digestion of BaSO 4 sources, allowing separation of thorium and subsequent determination of 228 Th activity. Although ingrowth periods for 228 Th can be lengthy, very low detection limits for 228 Ra can be achieved with this technique. - Highlights: • We developed two methods for 228 Ra measurement on Ba(Ra)SO 4 co-precipitation sources. • Measurement by gamma spectrometry using the daughter 228 Ac is rapid. • Detection limits are suitable for assessment of drinking water quality. • The second approach uses alpha spectrometry on a separated Th fraction. • This is more sensitive than gamma spectrometry after an ingrowth period greater than about 1 month

  7. Site decontamination

    International Nuclear Information System (INIS)

    Bicker, A.E.

    1981-01-01

    Among the several DOE sites that have been radiologically decontaminated under the auspices of the Nevada Operations Office are three whose physical characteristics are unique. These are the Tatum Dome Test Site (TDTS) near Hattiesburg, Mississippi; a location of mountainous terrain (Pahute Mesa) on the Nevada Test Site; and the GNOME site near Carlsbad, New Mexico. In each case the contamination, the terrain, and the climate conditions were different. This presentation includes a brief description of each site, the methods used to perform radiological surveys, the logistics required to support the decontamination (including health physics and sample analysis), and the specific techniques used to reduce or remove the contamination

  8. Skin decontamination: principles and perspectives.

    Science.gov (United States)

    Chan, Heidi P; Zhai, Hongbo; Hui, Xiaoying; Maibach, Howard I

    2013-11-01

    Skin decontamination is the primary intervention needed in chemical, biological and radiological exposures, involving immediate removal of the contaminant from the skin performed in the most efficient way. The most readily available decontamination system on a practical basis is washing with soap and water or water only. Timely use of flushing with copious amounts of water may physically remove the contaminant. However, this traditional method may not be completely effective, and contaminants left on the skin after traditional washing procedures can have toxic consequences. This article focuses on the principles and practices of skin decontamination.

  9. Production of mixed oxide fuel for fast reactor irradiation test by co-precipitation

    International Nuclear Information System (INIS)

    Todokoro, Akio; Masuda, Sumio; Naruki, Kaoru; Kaya, Akira; Koizumi, Masumichi

    1974-01-01

    Studies were made on the production of homogeneous mixed oxide by co-precipitation. Experiments were made on the effects of the addition rate of ammonia water, precipitation temperature, aging time of co-precipitate, and pH value. Plutonium refined by anion exchange was mixed with solution of uranium. The concentration of free acid in the mixed solution was adjusted to 1.5-2.0 M, and the total volume of the solution was made 3.01. The weight of Pu and U in the solution was 100g. The solution was kept at a definite temperature while being stirred. Concentrated ammonia solution was added to the solution at a definite rate. The precipitate thus formed was filtrated after aging, then dried for 24 hours at 100 +- 2 0 C. Dried co-precipitate was calcinated for 1 hr at 550 0 C. The reduction for 4 hours at 800 0 C gave the mixed powder of PuO 2 and UO 2 . After pressing, the powder was sintered for 2 hours at 1700 0 C. The shrinkage ratio decreased as the activity and tap density of the original powder increased. The activity determined by specific surface area increased as the rate of ammonia water addition increased, and as the precipitation temperature rose. Tap density was independent of the rate of addition of ammonia water. The activity of the powder increased and the tap density decreased as the aging time of precipitate increased. (Fukutomi, T.)

  10. Liberation of Adsorbed and Co-Precipitated Arsenic from Jarosite, Schwertmannite, Ferrihydrite, and Goethite in Seawater

    Directory of Open Access Journals (Sweden)

    Rodrigo Alarcón

    2014-07-01

    Full Text Available Sea level rise is able to change the geochemical conditions in coastal systems. In these environments, transport of contaminants can be controlled by the stability and adsorption capacity of iron oxides. The behavior of adsorbed and co-precipitated arsenic in jarosite, schwertmannite, ferrihydrite, and goethite in sea water (common secondary minerals in coastal tailings was investigated. The aim of the investigation was to establish As retention and transport under a marine flood scenario, which may occur due to climate change. Natural and synthetic minerals with co-precipitated and adsorbed As were contacted with seawater for 25 days. During this period As, Fe, Cl, SO4, and pH levels were constantly measured. The larger retention capability of samples with co-precipitated As, in relation with adsorbed As samples, reflects the different kinetics between diffusion, dissolution, and surface exchange processes. Ferrihydrite and schwertmannite showed good results in retaining arsenic, although schwertmannite holding capacity was enhanced due its buffering capacity, which prevented reductive dissolution throughout the experiment. Arsenic desorption from goethite could be understood in terms of ion exchange between oxides and electrolytes, due to the charge difference generated by a low point-of-zero-charge and the change in stability of surface complexes between synthesis conditions and natural media.

  11. Clinical aspects of percutaneous poisoning by the chemical warfare agent VX: effects of application site and decontamination.

    Science.gov (United States)

    Hamilton, Murray G; Hill, Ira; Conley, John; Sawyer, Thomas W; Caneva, Duane C; Lundy, Paul M

    2004-11-01

    O-ethyl S-(2-diisopropylaminoethyl) methylphosphonothioate (VX) is an extremely toxic organophosphate nerve agent that has been weaponized and stockpiled in a number of different countries, and it has been used in recent terrorist events. It differs from other well-known organophosphate nerve agents in that its primary use is as a contact poison rather than as an inhalation hazard. For this reason, we examined the effects of application site and skin decontamination on VX toxicity in anesthetized domestic swine after topical application. VX applied to the surface of the ear rapidly resulted in signs of toxicity consistent with the development of cholinergic crisis, including apnea and death. VX on the epigastrium resulted in a marked delayed development of toxic signs, reduced toxicity, and reduction in the rate of cholinesterase depression compared with animals exposed on the ear. Skin decontamination (15 minutes post-VX on the ear) arrested the development of clinical signs and prevented further cholinesterase inhibition and death. These results confirm earlier work that demonstrates the importance of exposure site on the resultant toxicity of this agent and they also show that decontamination postexposure has the potential to be an integral and extremely important component of medical countermeasures against this agent.

  12. Properties and solidification of decontamination wastes

    International Nuclear Information System (INIS)

    Davis, M.S.; Piciulo, P.L.; Bowerman, B.S.; Adams, J.W.; Milian, L.

    1983-01-01

    LWRs will require one or more chemical decontaminations to achieve their designed lifetimes. Primary system decontamination is designed to lower radiation fields in areas where plant maintenance personnel must work. Chemical decontamination methods are either hard (concentrated chemicals, approximately 5 to 25 weight percent) or soft (dilute chemicals less than 1 percent by weight). These methods may have different chemical reagents, some tailor-made to the crud composition and many methods are and will be proprietary. One factor common to most commercially available processes is the presence of organic acids and chelates. These types of organic reagents are known to enhance the migration of radionuclides after disposal in a shallow land burial site. The NRC sponsors two programs at Brookhaven National Laboratory that are concerned with the management of decontamination wastes which will be generated by the full system decontamination of LWRs. These two programs focus on potential methods for degrading or converting decontamination wastes to more acceptable forms prior to disposal and the impact of disposing of solidified decontamination wastes. The results of the solidification of simulated decontamination resin wastes will be presented. Recent results on combustion of simulated decontamintion wastes will be described and procedures for evaluating the release of decontamination reagents from solidified wastes will be summarized

  13. Evaluation of a decontamination model

    International Nuclear Information System (INIS)

    Rippin, D.W.T.; Hanulik, J.; Schenker, E.; Ullrich, G.

    1981-02-01

    In the scale-up of a laboratory decontamination process difficulties arise due to the limited understanding of the mechanisms controlling the process. This paper contains some initial proposals which may contribute to the quantitative understanding of the chemical and physical factors which influence decontamination operations. General features required in a mathematical model to describe a fluid-solid reaction are discussed, and initial work is presented with a simple model which has had some success in describing the observed laboratory behaviour. (Auth.)

  14. Effect of Gallium and Indium Co-Substituting on Upconversion Properties of Er/Yb:Yttrium Aluminum Garnet Powders Prepared by the Co-Precipitation Method.

    Science.gov (United States)

    Zhang, Wei; Liang, Yun-Ling; Hu, Zheng-Fa; Feng, Zu-Yong; Lun, Ma; Zhang, Xiu-ping; Sheng, Xia; Liu, Qian; Luo, Jie

    2016-04-01

    Gallium and Indium co-substituted Yb, Er:YAG was fabricated through the chemical co-precipitation method. The formation process and structure of the Ga3+ and In3+ substituted phosphor powders were characterized by the X-ray diffraction, thermo-gravimetry analyzer, infrared spectra, and X-ray photoelectron spectroscopy, and the effects of Ga3+ and In3+ concentration on the luminescence properties were investigated by spectrum. The results showed that the blue shift occurred after the substitution of Ga3+ and In3+ for Al3+ in matrix, and the intensity of emission spectrum was affected by the concentration of Ga3+ and In3+.

  15. Developments in Decontamination Technologies of Military Personnel and Equipment

    Science.gov (United States)

    Sata, Utkarsh R.; Ramkumar, Seshadri S.

    Individual protection is important for warfighters, first responders and civilians to meet the current threat of toxic chemicals and chemical warfare (CW) agents. Within the realm of individual protection, decontamination of warfare agents is not only required on the battlefield but also in laboratory, pilot plants, production and agent destruction sites. It is of high importance to evaluate various decontaminants and decontamination techniques for implementing the best practices in varying scenarios such as decontamination of personnel, sites and sensitive equipment.

  16. Development of a suppression method for deposition of radioactive cobalt after chemical decontamination: Confirmation of the Suppression Mechanism with Preoxidized Ferrite Film for Deposition of Radioactive Cobalt

    International Nuclear Information System (INIS)

    Ito, Tsuyoshi; Hosokawa, Hideyuki; Nagase, Makoto; Aizawa, Motohiro; Fuse, Motomasa

    2012-09-01

    Recently, chemical decontamination at the beginning of a periodical inspection is applied to many Japanese boiling water reactor (BWR) plants in order to reduce radiation exposure. In the chemical decontamination, the oxides that have incorporated 60 Co are dissolved using reductive and oxidative chemical reagents. Some of the piping stainless steel (SS) base metal is exposed to the reactor water after this decontamination. The oxide film growth rate of the piping during plant operation just after the decontamination is higher than that just before it. Therefore, there is a possibility that the deposition amount of 60 Co on the piping just after decontamination is higher than that just before the chemical decontamination. The Hi-F Coat (Hitachi ferrite coating) process has been developed to lower recontamination after the chemical decontamination. In this process, a fine Fe 3 O 4 coating film is formed on the piping SS base metal in aqueous solution at 363 K using three chemical reagents: ferrous ion, oxidant, and pH adjuster. The growth rate of the corrosion oxide film that incorporated 60 Co on the piping during plant operation is suppressed by the fine ferrite film that blocks both diffusion of oxidant in the reactor water to the SS base metal and metal ions in the oxide film to the reactor water. As a result, the amount of 60 Co deposition is suppressed by the Hi-F coating film. In a previous report, we found that the Hi-F Coat process lowered the amount of 60 Co to 1/3 that for non-coated specimens. To improve the suppression of 60 Co deposition further, we combined the Hi-F Coat process with a pre-oxidation step which we named the pre-oxidized Hi-F Coat process. In laboratory experiments, using the pre-oxidized Hi-F Coat process we found the deposited amount of 60 Co was 1/10 that for non-coated specimens. By combining the Hi-F Coat process with the pre-oxidation step, the suppression effect of 60 Co deposition was three times higher than that of the Hi

  17. Post-Decontamination Vapor Sampling and Analytical Test Methods

    Science.gov (United States)

    2015-08-12

    is decontaminated that could pose an exposure hazard to unprotected personnel. The chemical contaminants may include chemical warfare agents (CWAs... decontamination process. Chemical contaminants can include chemical warfare agents (CWAs) or their simulants, nontraditional agents (NTAs), toxic industrial...a range of test articles from coupons, panels, and small fielded equipment items. 15. SUBJECT TERMS Vapor hazard; vapor sampling; chemical warfare

  18. Decontaminating method

    International Nuclear Information System (INIS)

    Furukawa, Toshiharu; Shibuya, Kiichiro.

    1985-01-01

    Purpose: To provide a method of eliminating radioactive contaminations capable of ease treatment for decontaminated liquid wastes and grinding materials. Method: Those organic grinding materials such as fine wall nuts shell pieces cause no secondary contaminations since they are softer as compared with inorganic grinding materials, less pulverizable upon collision against the surface to be treated, being capable of reusing and producing no fine scattering powder. In addition, they can be treated by burning. The organic grinding material and water are sprayed by a nozzle to the surface to be treated, and decontaminated liquid wastes are separated into solid components mainly composed of organic grinding materials and liquid components mainly composed of water by filtering. The thus separated solid components are recovered in a storage tank for reuse as the grinding material and, after repeating use, subjected to burning treatment. While on the other hand, water is recovered into a storage tank and, after repeating use, purified by passing through an ion exchange resin-packed column and decontaminated to discharge. (Horiuchi, T.)

  19. Method for decontaminating radiation metal waste

    International Nuclear Information System (INIS)

    Onuma, Tsutomu; Tanaka, Akio; Akimoto, Hidetoshi

    1991-01-01

    This report describes a method for decontaminating radiation metal waste characterized by the following properties: in order to decontaminate radiation metal waste of various shapes produced by facilities involved with radioactive substances, non-complex shapes are decontaminated by electropolishing the materials in a neutral saline solution. Complex shapes are chemically decontaminated by means of an acid solution containing permanganic acid or an alkaline solution and a mineral acid solution. After neutralizing the solutions used for chemical decontamination, the radioactive material is separated and removed. Further, in the decontamination method for radioactive metal waste, a supernatant liquid is reused as the electrolyte in electropolishing decontamination. Permanganic ions (MnO 4 - ) are reduced to manganese dioxide (MnO 2 ) and deposited prior to neutralizing the solution used for chemical decontamination. Once manganese dioxide (MnO 2 ) has been separated and removed, it is re-used as the electrolyte in electropolishing decontamination by means of a process identical to the separation process for radioactive substances. 3 figs

  20. Synthesis of highly sinterable YAG nanopowders by a modified co-precipitation method

    International Nuclear Information System (INIS)

    Chen, Zhi-Hui; Yang, Yun; Hu, Zhang-Gui; Li, Jiang-Tao; He, Shu-Li

    2007-01-01

    A hydrate precursor of yttrium aluminum garnet (YAG) was synthesized by a modified co-precipitation method, in which n-butanol was employed as a low-cost recyclable dehydration solvent. A mixed solution of ethanol and ammonia were used as precipitant. Pure YAG phase appeared after the as-prepared precursors being calcined at 850 o C for 2 h. The nanocrystalline YAG particles calcined at 1100 o C were well dispersed with average diameter of about 40 nm, which can be densified to transparency under vacuum sintering at 1700 o C for 5 h with TEOS as sintering additive

  1. Comparison of structural and luminescence properties of Dy2O3 nanopowders synthesized by co-precipitation and green combustion routes

    International Nuclear Information System (INIS)

    Chandrasekhar, M.; Nagabhushana, H.; Sudheerkumar, K.H.; Dhananjaya, N.; Sharma, S.C.; Kavyashree, D.; Shivakumara, C.; Nagabhushana, B.M.

    2014-01-01

    Highlights: • Dy 2 O 3 nanopowders were prepared by co-precipitation and eco-friendly green combustion route using plant latex. • Both the products show excellent chromaticity coordinates in the white region, which were quite useful for white LED’s. • Thermoluminescence response of the Dy 2 O 3 product prepared by green synthesis was higher when compared to co-precipitation route. • Structural parameters of Dy 2 O 3 were estimated using Rietveld refinement. • The development of nanosize materials using eco-friendly resources was an attractive non-hazardous chemical route. - Abstract: Dysprosium oxide (Dy 2 O 3 ) nanopowders were prepared by co-precipitation (CP) and eco-friendly green combustion (GC) routes. SEM micrographs prepared by CP route show smooth rods with various lengths and diameters while, GC route show porous, agglomerated particles. The results were further confirmed by TEM. Thermoluminescence (TL) responses of the nanopowder prepared by both the routes were studied using γ-rays. A well resolved glow peak at 353 °C along with less intense peak at 183 °C was observed in GC route while, in CP a single glow peak at 364 °C was observed. The kinetic parameters were estimated using Chen’s glow peak route. Photoluminescence (PL) of Dy 2 O 3 shows peaks at 481, 577, 666 and 756 nm which were attributed to Dy 3+ transitions of 4 F 9/2 ⟶ 6 H 15/2 , 6 H 13/2 , 6 H 11/2 and 6 H 9/2 , respectively. Color co-ordinate values were located in the white region as a result the product may be useful for the fabrication of WLED’S

  2. Synthesis of aqueous suspensions of magnetic nanoparticles with the co-precipitation of iron ions in the presence of aspartic acid

    Energy Technology Data Exchange (ETDEWEB)

    Pušnik, Klementina; Goršak, Tanja [Department for Materials Synthesis, Jožef Stefan Institute, 1000 Ljubljana (Slovenia); Jožef Stefan International Postgraduate School, 1000 Ljubljana (Slovenia); Drofenik, Miha [Department for Materials Synthesis, Jožef Stefan Institute, 1000 Ljubljana (Slovenia); Faculty of Chemistry and Chemical Engineering, University of Maribor, 2000 Maribor (Slovenia); Makovec, Darko [Department for Materials Synthesis, Jožef Stefan Institute, 1000 Ljubljana (Slovenia); Jožef Stefan International Postgraduate School, 1000 Ljubljana (Slovenia)

    2016-09-01

    There is increasing demand for the production of large quantities of aqueous suspensions of magnetic iron-oxide nanoparticles. Amino acids are one possible type of inexpensive, nontoxic, and biocompatible molecules that can be used as the surfactants for the preparation of stable suspensions. This preparation can be conducted in a simple, one-step process based on the co-precipitation of Fe{sup 3+}/Fe{sup 2+} ions in the presence of the amino acid. However, the presence of this amino acid changes the mechanism of the magnetic nanoparticles' formation. In this investigation we analyzed the influence of aspartic amino acid (Asp) on the formation of magnetic iron-oxide nanoparticles during the co-precipitation. The process of the nanoparticles’ formation was followed using a combination of TEM, x-ray diffractometry, magnetic measurements, in-situ FT-IR spectroscopy, and chemical analysis, and compared with the formation of nanoparticles without the Asp. The Asp forms a coordination complex with the Fe{sup 3+} ions, which impedes the formation of the intermediate iron oxyhydroxide phase and suppresses the growth of the final magnetic iron-oxide nanoparticles. Slower reaction kinetics can lead to the formation of nonmagnetic secondary phases. The aspartic-acid-absorbed nanoparticles can be dispersed to form relatively concentrated aqueous suspensions displaying a good colloidal stability at an increased pH. - Highlights: • Co-precipitation of Fe{sup 3+}/Fe{sup 2+} ions in the presence of aspartic amino acid (Asp). • Through analysis of nanoparticle formation mechanism. • Presence of Asp changes the mechanism of the nanoparticles’ formation. • Asp forms a coordination complex with the Fe{sup 3+} ions. • Asp impedes the formation of iron oxyhydroxide phase and suppresses the growth of iron-oxide nanoparticles. • The aspartic-acid-absorbed nanoparticles form stable aqueous suspensions.

  3. Synthesis of aqueous suspensions of magnetic nanoparticles with the co-precipitation of iron ions in the presence of aspartic acid

    International Nuclear Information System (INIS)

    Pušnik, Klementina; Goršak, Tanja; Drofenik, Miha; Makovec, Darko

    2016-01-01

    There is increasing demand for the production of large quantities of aqueous suspensions of magnetic iron-oxide nanoparticles. Amino acids are one possible type of inexpensive, nontoxic, and biocompatible molecules that can be used as the surfactants for the preparation of stable suspensions. This preparation can be conducted in a simple, one-step process based on the co-precipitation of Fe 3+ /Fe 2+ ions in the presence of the amino acid. However, the presence of this amino acid changes the mechanism of the magnetic nanoparticles' formation. In this investigation we analyzed the influence of aspartic amino acid (Asp) on the formation of magnetic iron-oxide nanoparticles during the co-precipitation. The process of the nanoparticles’ formation was followed using a combination of TEM, x-ray diffractometry, magnetic measurements, in-situ FT-IR spectroscopy, and chemical analysis, and compared with the formation of nanoparticles without the Asp. The Asp forms a coordination complex with the Fe 3+ ions, which impedes the formation of the intermediate iron oxyhydroxide phase and suppresses the growth of the final magnetic iron-oxide nanoparticles. Slower reaction kinetics can lead to the formation of nonmagnetic secondary phases. The aspartic-acid-absorbed nanoparticles can be dispersed to form relatively concentrated aqueous suspensions displaying a good colloidal stability at an increased pH. - Highlights: • Co-precipitation of Fe 3+ /Fe 2+ ions in the presence of aspartic amino acid (Asp). • Through analysis of nanoparticle formation mechanism. • Presence of Asp changes the mechanism of the nanoparticles’ formation. • Asp forms a coordination complex with the Fe 3+ ions. • Asp impedes the formation of iron oxyhydroxide phase and suppresses the growth of iron-oxide nanoparticles. • The aspartic-acid-absorbed nanoparticles form stable aqueous suspensions.

  4. Magnetic and structural properties of Cu0.85Fe0.15O system synthesized by co-precipitation

    International Nuclear Information System (INIS)

    Colorado, H. D.; Pérez Alcázar, G. A.

    2011-01-01

    Cu 0.94 Fe 0.06 O and Cu 0.85 Fe 0.15 O samples were synthesized by using the co-precipitation chemical method. Starting from aqueous solutions of copper nitrate, CuO (NO 3 ) 2 3H 2 O, iron nitrate, Fe (NO 3 ) 3 9H 2 O and sodium hydroxide as precipitating agent, NaOH. The precipitate of three samples for Cu 0.94 Fe 0.06 O and five for Cu 0.85 Fe 0.15 O of fine powder were calcined for 5 h at different temperatures. The obtained X rays diffraction patterns refined by the Rietveld method show the CuO characteristic pattern, showing that the Fe atoms enter to replace Cu atoms. Furthermore, it was obtained that the crystallite size decreases with calcination temperatures for Cu 0.94 Fe 0.06 O. The transmission Mössbauer spectroscopy showed that the samples present a disordered paramagnetic behavior due to the big value of the half-width of line of the quadrupolar splitting. Vibrating sample magnetometry confirms the paramagnetic character. The XRD results indicate that the material is nanostructured, due that the crystallite sizes are of the order of 10 nm for Cu 0.94 Fe 0.06 O and 40 nm for Cu 0.85 Fe 0.15 O.

  5. Structural characterization, formation mechanism and stability of curcumin in zein-lecithin composite nanoparticles fabricated by antisolvent co-precipitation.

    Science.gov (United States)

    Dai, Lei; Sun, Cuixia; Li, Ruirui; Mao, Like; Liu, Fuguo; Gao, Yanxiang

    2017-12-15

    Curcumin (Cur) exhibits a range of bioactive properties, but its application is restrained due to its poor water solubility and sensitivity to environmental stresses. In this study, zein-lecithin composite nanoparticles were fabricated by antisolvent co-precipitation technique for delivery of Cur. The result showed that the encapsulation efficiency of Cur was significantly enhanced from 42.03% in zein nanoparticles to 99.83% in zein-lecithin composite nanoparticles. The Cur entrapped in the nanoparticles was in an amorphous state confirmed by differential scanning calorimetry and X-ray diffraction. Fourier transform infrared analysis revealed that hydrogen bonding, electrostatic interaction and hydrophobic attraction were the main interactions among zein, lecithin, and Cur. Compared with single zein and lecithin nanoparticles, zein-lecithin composite nanoparticles significantly improved the stability of Cur against thermal treatment, UV irradiation and high ionic strength. Therefore, zein-lecithin composite nanoparticles could be a potential delivery system for water-insoluble bioactive compounds with enhanced encapsulation efficiency and chemical stability. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Preparation of Fe3O4/Bentonite Nanocomposite from Natural Iron Sand by Co-precipitation Method for Adsorbents Materials

    Science.gov (United States)

    Sebayang, Perdamean; Kurniawan, Candra; Aryanto, Didik; Arief Setiadi, Eko; Tamba, Konni; Djuhana; Sudiro, Toto

    2018-03-01

    An adsorption method is one of the effective ways to filter the heavy metals wastes in aqueous system. In this paper, the Fe3O4/bentonite nanocomposites were successfully prepared from natural iron sand by co-precipitation method. The chemical process was carried out by dissolving and hot stirring the milled iron sand and bentonite in acid solution and precipitating it by NH4OH. The sediment was then washed using distilled water to neutralize pH and dried at 100 °C for 5 hours to produce Fe3O4/bentonite powders. The samples were characterized by XRD, FTIR, BET, TEM, VSM and AAS. All samples were composed by Fe3O4 single phase with a spinnel structure and lattice parameter of 8.373 Å. The transmittance peak of FTIR curve proved that the Fe3O4 particles and bentonite had a molecular bonding. The addition of bentonite to Fe3O4 nanoparticles generally reduced the magnetic properties of Fe3O4/bentonite nanocomposites. The optimum condition of 30 wt% bentonite resulted 105.9 m2/g in surface area, 14 nm in an average particle size and 3.2 nm in pore size. It can be used as Cu and Pb adsorbent materials.

  7. NRC regulations and positions concerning decontamination

    International Nuclear Information System (INIS)

    McCracken, C.

    1982-09-01

    The U.S. Nuclear Regulatory Commission encourages the use of decontamination to reduce man-rem exposure. The Commission feels that there are several processes developed to the point where soft decontamination can be applied to an entire plant in the near future. A utility can do a decontamination under its own licence without coming in for regulatory review if the process does not involve a change in technical specifications for the plant or does not involve unreviewed safety questions. Prior verbal notification is required for some steam generator secondary side cleaning or for decontamination of individual components that have not been removed from the reactor using chemicals not normally added to the reactor coolant. Prior written notification is required for steam generator secondary side crevice cleaning or sludge removal at a dented unit, or for chemical decontamination of reactor coolant systems or safety-related systems using chemicals not normally added to the coolant

  8. Characterization of γ- Al2O3 nanopowders synthesized by Co-precipitation method

    International Nuclear Information System (INIS)

    Jbara, Ahmed S.; Othaman, Zulkafli; Ati, Ali A.; Saeed, M.A.

    2017-01-01

    Co-precipitation technique has been used to synthesize gamma-Al 2 O 3 (γ-Al 2 O 3 ) nanopowders under annealing temperature effect. The crystalline phase and purity for the prepared powder were characterized by different spectroscopy techniques. XRD analysis confirms the gamma phase of alumina nanopowders with particle diameter ranging from 6 to 24 nm, which confirms the quantum dots formation, which is also supported by the BET measurement. The surface area of the prepared nanopowders is in the range of 109–367 m 2 /g. Morphology analysis indicates that γ-Al 2 O 3 nanopowders are consisted of grains almost spherical in shape. Some agglomeration of nanoparticles occurs, which become more regular hexagonal shaped with the increasing annealing temperature. The small nanoparticles size and the high surface area from a simple procedure for preparing γ-Al 2 O 3 may make it more suitable for use as an adsorbent for malachite green. - Highlights: • Co-precipitation technique is used to synthesize gamma- Al 2 O 3 nanopowders. • Pure gamma- Al 2 O 3 phase was obtained having maximum nanoparticle size is 24 nm. • The quantum dots were formed inside powder. • High surface area of nanopowders at the low annealing temperature. • Increasing annealing temperature causes the hexagonal agglomeration shape.

  9. Gas sensing properties of magnesium ferrite prepared by co-precipitation method

    International Nuclear Information System (INIS)

    Hankare, P.P.; Jadhav, S.D.; Sankpal, U.B.; Patil, R.P.; Sasikala, R.; Mulla, I.S.

    2009-01-01

    Polycrystalline magnesium ferrite (MgFe 2 O 4 ) was prepared by the co-precipitation method. The synthesized compound was characterized for their phase and morphology by X-ray diffraction and scanning electron microscopy, respectively. Conductance responses of the (MgFe 2 O 4 ) were measured towards gases like hydrogen sulfide (H 2 S), liquefied petroleum gas (LPG), ethanol vapors (C 2 H 5 OH), SO x , H 2 , NO x , NH 3, methanol, acetone and petrol. The gas sensing characterstics were obtained by measuring the sensitivity as a function of various controlling factors like operating temperatures and concentrations of gases. It was found that the sensor exhibited various responses towards these gases at different operating temperatures. Furthermore; the MgFe 2 O 4 based sensor exhibited a fast response and a good recovery towards petrol at temperature 250 deg. C. The results of the response towards petrol reveal that (MgFe 2 O 4 ) synthesized by a simple co-precipitation method, would be a suitable material for the fabrication of the petrol sensor.

  10. Co-precipitation of oppositely charged nanoparticles: the case of mixed ligand nanoparticles

    International Nuclear Information System (INIS)

    Moglianetti, Mauro; Ponomarev, Evgeniy; Szybowski, Maxime; Stellacci, Francesco; Reguera, Javier

    2015-01-01

    Colloid stability is of high importance in a multitude of fields ranging from food science to biotechnology. There is strong interest in studying the stability of small particles (of a size of a few nanometres) with complex surface structures, that make them resemble the complexity of proteins and other natural biomolecules, in the presence of oppositely charged nanoparticles. While for nanoparticles with homogeneously charged surfaces an abrupt precipitation has been observed at the neutrality of charges, data are missing about the stability of nanoparticles when they have more complex surface structures, like the presence of hydrophobic patches. To study the role of these hydrophobic patches in the stability of nanoparticles a series of negatively charged nanoparticles has been synthesized with different ratios of hydrophobic content and with control on the structural distribution of the hydrophobic moiety, and then titrated with positively charged nanoparticles. For nanoparticles with patchy nanodomains, the influence of hydrophobic content was observed together with the influence of the size of the nanoparticles. By contrast, for nanoparticles with a uniform distribution of hydrophobic ligands, size changes and hydrophobic content did not play any role in co-precipitation behaviour. A comparison of these two sets of nanoparticles suggests that nanodomains present at the surfaces of nanoparticles are playing an important role in stability against co-precipitation. (paper)

  11. On preparation of nanocrystalline chromites by co-precipitation and autocombustion methods

    Energy Technology Data Exchange (ETDEWEB)

    Matulkova, Irena [Department of Inorganic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 8, 128 43 Prague 2 (Czech Republic); Department of Radiation and Chemical Physics, Institute of Physics of the ASCR, v.v.i., Na Slovance 2, 182 21 Prague 8 (Czech Republic); Holec, Petr [Department of Inorganic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 8, 128 43 Prague 2 (Czech Republic); Department of Materials Chemistry, Institute of Inorganic Chemistry of the ASCR, v.v i., Husinec-Rez 1001, 250 68 Rez (Czech Republic); Pacakova, Barbara; Kubickova, Simona; Mantlikova, Alice [Department of Magnetic Nanosystems, Institute of Physics of the ASCR, v.v.i., Na Slovance 2, 182 21 Prague 8 (Czech Republic); Plocek, Jiri [Department of Materials Chemistry, Institute of Inorganic Chemistry of the ASCR, v.v i., Husinec-Rez 1001, 250 68 Rez (Czech Republic); Nemec, Ivan; Niznansky, Daniel [Department of Inorganic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 8, 128 43 Prague 2 (Czech Republic); Vejpravova, Jana, E-mail: vejpravo@fzu.cz [Department of Magnetic Nanosystems, Institute of Physics of the ASCR, v.v.i., Na Slovance 2, 182 21 Prague 8 (Czech Republic)

    2015-05-15

    Highlights: • ACr{sub 2}O{sub 4} nanopowders, A = Cu, Fe, Ni, Mn and Mg were obtained in high yield. • Co-precipitation and autocombustion routes were optimized for single-phase product. • The nanopowders were examined by X-ray diffraction and vibrational spectroscopy. • Formation of cubic or tetragonal phase in Jahn–Teller NiCr{sub 2}O{sub 4} can be controlled. - Abstract: We present a comprehensive study on optimization of wet preparation routes yielding well-crystalline spinel chromite, ACr{sub 2}O{sub 4} nanoparticles (A = Cu, Fe, Ni, Mn and Mg). The auto-combustion and co-precipitation methods in the presence of nitrate or chloride ions and under different atmospheres, followed by annealing of final products at different temperatures were tested. All samples were characterized by powder X-ray diffraction (PXRD) and vibrational spectroscopy in order to evaluate their phase composition, particle size and micro-strain. Selected samples were subjected to investigation by transmission electron microscopy (TEM). The degree of the particle crystallinity was estimated by relating the apparent crystallite size obtained from the PXRD analysis to the physical grain size observed by the TEM. Optimal conditions leading to single-phase and highly-crystalline chromite nanoparticles are proposed.

  12. Co-precipitation synthesis of YAG:Dy nanophosphor and its thermometric properties

    International Nuclear Information System (INIS)

    Chong, Joo-Yun; Zhang, Yuelan; Wagner, Brent K.; Kang, Zhitao

    2013-01-01

    Highlights: •YAG:Dy nanophosphors were synthesized with particle size of about 50 nm. •Optimized doping concentration of 6%Dy was determined. •Thermometric photoluminescence properties were studied between 20 and 350 °C. •Temperature-sensitive change in peak ratio of 496/457 nm emissions was demonstrated. •Suitable for potential thermographic applications when dispersed in a liquid media. -- Abstract: Dy 3+ doped yttrium aluminum garnet (YAG) nanophosphors were synthesized by a co-precipitation method for potential thermographic applications in a liquid media dispersed with fluorescent nanoparticles. The doping concentration and annealing temperature on the structural and optical properties of YAG:Dy were investigated. Pure phase YAG:Dy nanophosphors were obtained by annealing the co-precipitated hydroxide products at above 900 °C. Maximum photoluminescence intensity was observed from 6%Dy doped YAG samples. The effect of measuring temperature between 20 and 350 °C on the photoluminescence spectra of nano YAG:Dy was investigated. A temperature-sensitive change in the peak intensity ratio of 496/457 nm emission lines was demonstrated for such nanophosphors for the first time, suggesting potential applications in temperature monitoring of fuel spray

  13. Co-precipitation synthesis of YAG:Dy nanophosphor and its thermometric properties

    Energy Technology Data Exchange (ETDEWEB)

    Chong, Joo-Yun [School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Zhang, Yuelan [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Wagner, Brent K. [Georgia Tech Research Institute, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Kang, Zhitao, E-mail: zhitao.kang@gtri.gatech.edu [Georgia Tech Research Institute, Georgia Institute of Technology, Atlanta, GA 30332 (United States); School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States)

    2013-12-25

    Highlights: •YAG:Dy nanophosphors were synthesized with particle size of about 50 nm. •Optimized doping concentration of 6%Dy was determined. •Thermometric photoluminescence properties were studied between 20 and 350 °C. •Temperature-sensitive change in peak ratio of 496/457 nm emissions was demonstrated. •Suitable for potential thermographic applications when dispersed in a liquid media. -- Abstract: Dy{sup 3+} doped yttrium aluminum garnet (YAG) nanophosphors were synthesized by a co-precipitation method for potential thermographic applications in a liquid media dispersed with fluorescent nanoparticles. The doping concentration and annealing temperature on the structural and optical properties of YAG:Dy were investigated. Pure phase YAG:Dy nanophosphors were obtained by annealing the co-precipitated hydroxide products at above 900 °C. Maximum photoluminescence intensity was observed from 6%Dy doped YAG samples. The effect of measuring temperature between 20 and 350 °C on the photoluminescence spectra of nano YAG:Dy was investigated. A temperature-sensitive change in the peak intensity ratio of 496/457 nm emission lines was demonstrated for such nanophosphors for the first time, suggesting potential applications in temperature monitoring of fuel spray.

  14. Gadolinium-doped ceria nanopowders synthesized by urea-based homogeneous co-precipitation (UBHP)

    Energy Technology Data Exchange (ETDEWEB)

    Accardo, G., E-mail: d16605@kist.re.kr [Fuel Cell Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Spiridigliozzi, L. [Department of Civil and Mechanical Engineering, INSTM Research Unit, University of Cassino and Southern Lazio, Via G. Di Biasio 43, 03043 Cassino, FR (Italy); Cioffi, R.; Ferone, C. [Department of Engineering, INSTM Research Unit, University Parthenope of Naples, Centro Direzionale, Is. C4, 80143 Napoli (Italy); Di Bartolomeo, E. [Department of Chemical Science and Technology, University of Rome “Tor Vergata”, Viale della Ricerca Scientifica, 00133 Rome (Italy); Yoon, Sung Pil [Fuel Cell Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Dell’Agli, G. [Department of Civil and Mechanical Engineering, INSTM Research Unit, University of Cassino and Southern Lazio, Via G. Di Biasio 43, 03043 Cassino, FR (Italy)

    2017-02-01

    Gadolinium (10%)-doped ceria was successfully synthesized by using an urea-based co-precipitation method (UBHP). A single fluorite phase was obtained after a low temperature (400 °C) calcination treatment. The resulting powders showed grains of nanometric size with some agglomerations and an overall good sinterability. Pellets were sintered at 1300 and 1500 °C for 3 h. The ionic conductivity was measured by electrochemical impedance spectroscopy measurements and a correlation between electrical properties and microstructure was revealed. The promising conductivity values showed that the synthesized powders are suitable for intermediate temperature solid oxide fuel cells (IT-SOFCs) applications. - Highlights: • Urea-based homogeneous co-precipitation is applied to synthesize nanocrystalline GDC. • Dense GDC samples at different sintering temperatures were characterized. • SEM and TEM revealed a well define microstructure and controlled composition. • Correlation between electrochemical properties by EIS and microstructure was discussed. • UBHP method can be used to prepare high performance GDC electrolytes.

  15. Decontamination Data - Blister Agents

    Data.gov (United States)

    U.S. Environmental Protection Agency — Decontamination efficacy data for blister agents on various building materials using various decontamination solutions. This dataset is associated with the following...

  16. Specific decontamination methods: water nozzle, cavitation erosion

    International Nuclear Information System (INIS)

    Boulitrop, D.; Gauchon, J.P.; Lecoffre, Y.

    1984-05-01

    The erosion and decontamination tests carried out in the framework of this study, allowed to specify the fields favourable to the use of the high pressure jet taking into account the determinant parameters that are the pressure and the target-nozzle distance. The previous spraying of gels with chemical reagents (sulfuric acid anf hydrazine) allows to get better decontamination factors. Then, the feasibility study of a decontamination method by cavitation erosion is presented. Gelled compounds for decontamination have been developed; their decontamination quality has been evaluated by comparative contamination tests in laboratory and decontamination tests of samples of materials used in nuclear industry; this last method is adapted to remote handling devices and produces a low quantity of secondary effluents, so it allows to clean high contaminated installation on the site without additional exposure of the personnel [fr

  17. Decontamination of polyvinylchloride- and rubber type flooring

    International Nuclear Information System (INIS)

    Kunze, S.

    1975-01-01

    These types, fabricated by mixing of the basic components, showed no relation between content of fillers and decontamination results. Decontamination results are partly poorer, if the flooring contains a high concentration of the filler, especially if the latter consists mainly of hydrophilic materials. The coloring of the floorings seems to have no influence on the decontamination but floorings with clearly separated patterns can not be recommended for nuclear facilities. Fabricated by chemical reactions between polymeres, vulcanization materials and fillers, the decontamination results depend definitely from the proper choice of the filler. Flooring types, containing lampblack, graphite, kaoline, barium sulfate and titanium oxide are easy to decontamine. Again, increasing contents of hydrophilic filler cause a fall off in the decontamination results. (orig.) [de

  18. Formerly utilized MED/AEC sites Remedial Action Program. Report of the decontamination of Jones Chemical Laboratory, Ryerson Physical Laboratory, and Eckhart Hall, the University of Chicago, Chicago, Illinois

    Energy Technology Data Exchange (ETDEWEB)

    Wynuveen, R.A.; Smith, W.H.; Sholeen, C.M.; Flynn, K.F.

    1984-08-01

    The US Department of Energy (DOE) has implemented a program to decontaminate radioactively contaminated sites that were formerly utilized by the Manhattan Engineer District (MED) and/or the Atomic Energy Commission (AEC) for activities that included handling of radioactive material. This program is referred to as the ''Formerly Utilized Sites Remedial Action Program'' (FUSRAP). Among these sites are Jones Chemical Laboratory, Ryerson Physical Laboratory, Kent Chemical Laboratory, and Eckhart Hall of The University of Chicago, Chicago, Illinois. Since 1977, the University of Chicago decontaminated Kent Chemical Laboratory as part of a facilities renovation program. All areas of Eckhart Hall, Ryerson Physical Laboratory, and Jones Chemical Laboratory that had been identified as contaminated in excess of current guidelines in the 1976-1977 surveys were decontaminated to levels where no contamination could be detected relative to natural backgrounds. All areas that required defacing to achieve this goal were restored to their original condition. The radiological evaluation of the sewer system, based primarily on the radiochemical analyses of sludge and water samples, indicated that the entire sewer system is potentially contaminated. While this evaluation was defined as part of this project, the decontamination of the sewer system was not included in the purview of this effort. The documentation included in this report substantiates the judgment that all contaminated areas identified in the earlier reports in the three structures included in the decontamination effort (Eckhart Hall, Ryerson Physical Laboratory, and Jones Chemical Laboratory) were cleaned to levels commensurate with release for unrestricted use.

  19. Cutaneous challenge with chemical warfare agents in the SKH-1 hairless mouse (II): effects of some currently used skin decontaminants (RSDL and Fuller's earth) against liquid sulphur mustard and VX exposure.

    Science.gov (United States)

    Taysse, L; Dorandeu, F; Daulon, S; Foquin, A; Perrier, N; Lallement, G; Breton, P

    2011-06-01

    Using the hairless mouse screening model presented in the companion paper(1) the aim of this study was to assess two skin decontaminating systems: Fuller's earth (FE) and Reactive Skin Decontamination Lotion (RSDL) against two extremely toxic chemical warfare agents that represent a special percutaneous hazard, sulphur mustard (SM) and O-ethyl-S-(2[di-isopropylamino]ethyl)methyl-phosphonothioate (VX). Five minutes after being exposed on the back to either 2 µL of neat sulphur mustard or 50 µg.kg(-1) of diluted VX, mice were decontaminated. Both systems were able to reduce blisters 3 days after SM exposure. However, RSDL was found to be more efficient than FE in reducing the necrosis of the epidermis and erosion. In the case of VX exposure, RSDL, whatever the ratio of decontaminant to toxicant used (RSDL 10, 20, 50), was not able to sufficiently prevent the inhibition of plasma cholinesterases taken as a surrogate marker of exposure and toxicity. Only FE reduced significantly the ChE inhibition. Some of these observations are different from our previous results obtained in domestic swine and these changes are thus discussed in the perspective of using SKH-1 hairless mice for the initial in vivo screening of decontaminants.

  20. Decontamination and renovation of the Master/Slave Manipulator Repair Shop and the Chemical Crane Room at the West Valley Demonstration Project. Final topical report, June 1982-June 1983

    International Nuclear Information System (INIS)

    Phillips, E.C.; Golden, M.P.

    1986-01-01

    This report describes the decontamination and renovation of the Master/Slave Manipulator Repair Shop (MSMRS) and the Chemical Crane Room (CCR) at the WVDP from radioactively contaminated conditions to essentially shirt sleeve environments. In both cases, subsequent use recontaminated the rooms. Before decontamination, general exposure rates as high as 20 mrad/hr and surface contamination as high as 10 5 dpm/100 cm 2 were measured in the MSMRS, while general exposure rates in the CCR were 50 to 100 mrad/hr with hot spots as high as 2000 mrad/hr. Smearable levels on the floor in each room were in the range of 10 5 to 10 6 dpm per 100/cm 2 . Respiratory protection was mandatory for entry into the CCR. The MSMRS, located at the north end of the Process Building on ground elevation, is needed for the refurbishment of plant manipulators and other equipment. The MSMRS has been decontaminated and renovated as follows: all tools, equipment and furnishings were removed, the walls were stripped and repainted, and the contaminated concrete floor was removed and disposal of as low-level waste. A new concrete floor was poured and a stainless steel liner covering the entire floor and extending 45.7 cm up the walls was added to provide the WVDP with a shop facility that can be easily decontaminated. Decontamination of the MSMRS has been completed and the facility is available for service. The CCR, located at the north end of the Chemical Process Cell (CPC) is for the storage and servicing of two bridge cranes used in the CPC. Decontamination and exposure reduction in the CCR has been completed using vacuum cleaning, damp wipe down, and surface grinding followed by shielding and painting

  1. Synthesis of aqueous suspensions of magnetic nanoparticles with the co-precipitation of iron ions in the presence of aspartic acid

    Science.gov (United States)

    Pušnik, Klementina; Goršak, Tanja; Drofenik, Miha; Makovec, Darko

    2016-09-01

    There is increasing demand for the production of large quantities of aqueous suspensions of magnetic iron-oxide nanoparticles. Amino acids are one possible type of inexpensive, nontoxic, and biocompatible molecules that can be used as the surfactants for the preparation of stable suspensions. This preparation can be conducted in a simple, one-step process based on the co-precipitation of Fe3+/Fe2+ ions in the presence of the amino acid. However, the presence of this amino acid changes the mechanism of the magnetic nanoparticles' formation. In this investigation we analyzed the influence of aspartic amino acid (Asp) on the formation of magnetic iron-oxide nanoparticles during the co-precipitation. The process of the nanoparticles' formation was followed using a combination of TEM, x-ray diffractometry, magnetic measurements, in-situ FT-IR spectroscopy, and chemical analysis, and compared with the formation of nanoparticles without the Asp. The Asp forms a coordination complex with the Fe3+ ions, which impedes the formation of the intermediate iron oxyhydroxide phase and suppresses the growth of the final magnetic iron-oxide nanoparticles. Slower reaction kinetics can lead to the formation of nonmagnetic secondary phases. The aspartic-acid-absorbed nanoparticles can be dispersed to form relatively concentrated aqueous suspensions displaying a good colloidal stability at an increased pH.

  2. Study of UO2-10WT%Gd2O3 fuel pellets obtained by seeding method using AUC co-precipitation and mechanical mixing processes

    International Nuclear Information System (INIS)

    Lima, M.M.F.; Ferraz, W.B.A.; Santos, M.M. dos; Pinto, L.C.M.; Santos, A.

    2008-01-01

    The use of gadolinium and uranium mixed oxide as a nuclear fuel aims to obtain a fuel with a performance better than that of UO 2 fuel. In this work, seeding method was used to improve ionic diffusivity during sintering to produce high density pellets containing coarse grains by co-precipitation and mechanical mixing processes. Sintered UO 2 -10 wt% Gd 2 O 3 pellets were obtained using the reference processes with 2 wt% and 5 wt% UO 2 seeds with two granulometries, less than 20 μm and between 20 and 38 μm. Characterisation was carried out by chemical analysis, surface area, X-ray diffraction, SEM, WDS, image analysis, and densitometry. The seeding method using mechanical mixing process was more effective than the co-precipitation method. Furthermore, mechanical mixing process resulted in an increase in density of UO 2 -10wt% Gd 2 O 3 with seeds in relation to that of UO 2 -10wt% Gd 2 O 3 without seeds. (author)

  3. Decontamination impacts on solidification

    International Nuclear Information System (INIS)

    Piciulo, P.L.; Davis, M.S.

    1985-01-01

    The increased occupational exposure resulting from the accumulation of activated corrosion products in the primary system of LWRs has led to the development of chemical methods to remove the contamination. In the past, the problem of enhanced migration of radionuclides away from trenches used to dispose of low-level radioactive waste, has been linked to the presence, at the disposal unit, of chelating or complexing agents such as those used in decontamination processes. These agents have further been found to reduce the normal sorptive capacity of soils for radionuclides. The degree to which these agents inhibit the normal sorptive processes is dependent on the type of complexing agent, the radionuclide of concern, the soil properties and whether the nuclide is present as a complex or is already sorbed to the soil. Since the quantity of reagent employed in a full system decontamination is large (200 to 25,000 kg), the potential for enhanced migration of radionuclides from a site used to dispose of the decontamination wastes should be addressed and guidelines established for the safe disposal of these wastes

  4. Processing, structure and magnetic properties correlation in co-precipitated Ca-ferrite

    Energy Technology Data Exchange (ETDEWEB)

    Abasht, Behzad, E-mail: abasht@gmail.com [Space Thruster Research Institute, Iranian Space Research Center, Tabriz (Iran, Islamic Republic of); Department of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Beitollahi, Ali; Mirkazemi, Seyyed Mohammad [Department of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of)

    2016-12-15

    La-substituted hexagonal calcium ferrite, Ca{sub 1−X}La{sub X}Fe{sub 12}O{sub 19} (x varies from 0 to 0.6 with the step of 0.2), was synthesized by applying co-precipitation method, in which the molar ratio of Fe{sup 3+}/(Ca{sup 2+}+La{sup 2+}) was 11. The ferrite precursors were prepared from aqueous solution of calcium nitrate, ferric nitrate and lanthanum nitrate by co-precipitation of calcium, iron and lanthanum ions by using an aqueous base of sodium hydroxide (1.5 M) at the pH of 14 and at room temperature. These precursors were calcinated with different amount of La at different temperature of 700, 1100 and 1200 °C for constant calcination time of 1 h in a static air atmosphere. Some tests such as simultaneous thermal analysis (STA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM) were carried out to investigate the thermal behavior, crystallographic properties, morphology and magnetic properties of the precursor powders which were calcinated at different temperatures. The powder XRD patterns of samples which consisted of La as dopant and were calcinated at 1200 °C for 1 h, indicates the formation of calcium hexaferrite and also α-Fe{sub 2}O{sub 3} besides Magnetoplumbite-phase (M-phase). However, the results showed that CaFe{sub 4}O{sub 7} and α-Fe{sub 2}O{sub 3} phases were formed in the sample with the same condition but without using any dopant. The results of SEM showed that the calcium hexaferrite particle were regular hexagonal platelets with the size range of 1–2 µm. The magnetic properties such as maximum magnetization (M{sub Max}), remanent magnetization (M{sub r}) and coercivity (H{sub c}) were measured from the hysteresis loops. Low values of coercive field (16.3 kA m{sup −1}) and maximum magnetization (50.6 A m{sup 2} kg{sup −1}) were obtained from calcium hexaferrite particle in optimum amount of La (X=0.4) which calcinated at the temperature of 1200 °C. - Highlights: • In this

  5. Granulated decontamination formulations

    Science.gov (United States)

    Tucker, Mark D.

    2007-10-02

    A decontamination formulation and method of making that neutralizes the adverse health effects of both chemical and biological compounds, especially chemical warfare (CW) and biological warfare (BW) agents, and toxic industrial chemicals. The formulation provides solubilizing compounds that serve to effectively render the chemical and biological compounds, particularly CW and BW compounds, susceptible to attack, and at least one reactive compound that serves to attack (and detoxify or kill) the compound. The formulation includes at least one solubilizing agent, a reactive compound, a sorbent additive, and water. A highly adsorbent sorbent additive (e.g., amorphous silica, sorbitol, mannitol, etc.) is used to "dry out" one or more liquid ingredients into a dry, free-flowing powder that has an extended shelf life, and is more convenient to handle and mix in the field.

  6. Decontamination and decommissioning of the extraction chemical room at the West Valley Demonstration Project. Final topical report, December 1982-April 1984

    International Nuclear Information System (INIS)

    Phillips, E.C.

    1985-12-01

    The purpose of this report is to describe the preparation of a facility for use in decontaminating and decommissioning (D and D) extraction cells at the West Valley Demonstration Project (WVDP). In order to prepare such a facility, it was necessary to decontaminate, decommission and equip the Extraction Chemical Room (XCR) at the WVDP. This report describes the D and D of the XCR from a radioactively contaminated condition to an essentially shirt sleeve environment. Also included is a description of the changes made to the XCR for use in the D and D of the extraction cells which are located beneath the floor of the XCR. In the XCR prior to D and D, radiological surveys indicated a maximum radiation field of 5 mrad/hr, due to sources internal to the room, and 20,000 dpm beta/100 cm 2 surface contamination. A radiation source external to the XCR caused a hot spot with a 9 mrad/hr exposure rate inside the XCR. The D and D of the XCR, located on the fifth floor elevation 48.8 m of the reprocessing plant at the WVDP, has been completed. D and D operations included removal of piping, tanks, supports, and equipment to provide a clean work area of about 278.7 m 2 and 5.2 m high. Subsequent to the removal of piping and equipment, a new floor was installed in part of the room and equipment for use in the D and D of the extraction cells was added. The equipment included a large containment tent over the extraction cell hatches, a jib crane, two gantries, a monorail crane, an air transporter, and a temporary ventilation system. D and D operations in the XCR were initiated in December 1982 and the completed facility was available for use in February 1984

  7. Decontamination Strategy for Large Area and/or Equipment Contaminated with Chemical and Biological Agents using a High Energy Arc Lamp (HEAL)

    Energy Technology Data Exchange (ETDEWEB)

    Schoske, Richard [ORNL; Kennedy, Patrick [ORNL; Duty, Chad E [ORNL; Smith, Rob R [ORNL; Huxford, Theodore J [ORNL; Bonavita, Angelo M [ORNL; Engleman, Greg [ORNL; Vass, Arpad Alexander [ORNL; Griest, Wayne H [ORNL; Ilgner, Ralph H [ORNL; Brown, Gilbert M [ORNL

    2009-04-01

    A strategy for the decontamination of large areas and or equipment contaminated with Biological Warfare Agents (BWAs) and Chemical Warfare Agents (CWAs) was demonstrated using a High Energy Arc Lamp (HEAL) photolysis system. This strategy offers an alternative that is potentially quicker, less hazardous, generates far less waste, and is easier to deploy than those currently fielded by the Department of Defense (DoD). For example, for large frame aircraft the United States Air Force still relies on the combination of weathering (stand alone in environment), air washing (fly aircraft) and finally washing the aircraft with Hot Soapy Water (HSW) in an attempt to remove any remaining contamination. This method is laborious, time consuming (upwards of 12+ hours not including decontamination site preparation), and requires large amounts of water (e.g., 1,600+ gallons for a single large frame aircraft), and generates large amounts of hazardous waste requiring disposal. The efficacy of the HEAL system was demonstrated using diisopropyl methyl phosphonate (DIMP) a G series CWA simulant, and Bacillus globigii (BG) a simulant of Bacillus anthracis. Experiments were designed to simulate the energy flux of a field deployable lamp system that could stand-off 17 meters from a 12m2 target area and uniformly expose a surface at 1360 W/m2. The HEAL system in the absence of a catalyst reduced the amount of B. globigii by five orders of magnitude at a starting concentration of 1.63 x 107 spores. In the case of CWA simulants, the HEAL system in the presence of the catalyst TiO2 effectively degraded DIMP sprayed onto a 100mm diameter Petri dish in 5 minutes.

  8. DECONTAMINATION TECHNOLOGIES FOR FACILITY REUSE

    International Nuclear Information System (INIS)

    Bossart, Steven J.; Blair, Danielle M.

    2003-01-01

    As nuclear research and production facilities across the U.S. Department of Energy (DOE) nuclear weapons complex are slated for deactivation and decommissioning (D and D), there is a need to decontaminate some facilities for reuse for another mission or continued use for the same mission. Improved technologies available in the commercial sector and tested by the DOE can help solve the DOE's decontamination problems. Decontamination technologies include mechanical methods, such as shaving, scabbling, and blasting; application of chemicals; biological methods; and electrochemical techniques. Materials to be decontaminated are primarily concrete or metal. Concrete materials include walls, floors, ceilings, bio-shields, and fuel pools. Metallic materials include structural steel, valves, pipes, gloveboxes, reactors, and other equipment. Porous materials such as concrete can be contaminated throughout their structure, although contamination in concrete normally resides in the top quarter-inch below the surface. Metals are normally only contaminated on the surface. Contamination includes a variety of alpha, beta, and gamma-emitting radionuclides and can sometimes include heavy metals and organic contamination regulated by the Resource Conservation and Recovery Act (RCRA). This paper describes several advanced mechanical, chemical, and other methods to decontaminate structures, equipment, and materials

  9. Green and red luminescence in co-precipitation synthesized Pr:LuAG nanophosphor

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S. Arun; Kumar, K. Ashok; Gunaseelan, M.; Senthilselvan, J., E-mail: jsselvan@hotmail.com [Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai–600 025, Tamil Nadu (India); Asokan, K. [Materials Science Group, Inter University Accelerator Centre, New Delhi-110067 (India)

    2016-05-06

    Pr:LuAG nanophosphor is an effective candidate in magnetic resonance imaging coupled positron emission tomography (MRI-PET) for medical imaging and scintillator applications. LuAG:Pr (0.05, 0.15 mol%) nanoscale ceramic powders were synthesized by co-precipitation method using urea as precipitant. Effect of antisite defect on structure and luminescence behavior was investigated. Pr:LuAG nanoceramic powders are found crystallized in cubic structure by high temperature calcination at 1400 °C and it shows antisite defect. HR-SEM analysis revealed spherically shaped Pr:LuAG nanoceramic particulate powders with ∼100 nm size. By the excitation at 450 nm, Pr:LuAG nanophosphor exhibit green to red luminescence in the wavelength range of 520 to 680 nm, which is originated from multiplet transition of Pr{sup 3+} ions.

  10. Synthesis of cerium oxide (CeO{sub 2}) nanoparticles using simple CO-precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Farahmandjou, M.; Zarinkamar, M.; Firoozabadi, T. P., E-mail: farahamndjou@iauvaramin.ac.ir [Islamis Azad University, Varamin-Phisva Branch, Department of Physics, Varamin (Iran, Islamic Republic of)

    2016-11-01

    Synthesis of cerium oxide (CeO{sub 2}) nanoparticles was studied by new and simple co-precipitation method. The cerium oxide nanoparticles were synthesized using cerium nitrate and potassium carbonate precursors. Their physicochemical properties were characterized by high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (Sem), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (Ftir) and UV-Vis spectrophotometer. XRD pattern showed the cubic structure of the cerium oxide nanoparticles. The average particle size of CeO{sub 2} was around 20 nm as estimated by XRD technique and direct HRTEM observations. The surface morphological studies from Sem and Tem depicted spherical particles with formation of clusters. The sharp peaks in Ftir spectrum determined the existence of CeO{sub 2} stretching mode and the absorbance peak of UV-Vis spectrum showed the bandgap energy of 3.26 eV. (Author)

  11. FTIR and structural properties of co-precipitated cobalt ferrite nano particles

    International Nuclear Information System (INIS)

    Hutamaningtyas, E.; Utari; Suharyana; Purnama, B.; Wijayanta, A. T.

    2016-01-01

    The FTIR and structural properties in co-precipitated cobalt ferrite (CoFe 2 O 4 ) nanoparticles are discussed in this paper. The synthesis was conducted at temperatures of 75°C and 95°C following post annealing at 1200°C for 5 hours. Other modification samples were synthesis at temperature of 95°C and then annealing at temperature of 1000°C and 1200°C for 5 hours. For both modification of synthesis and annealing temperature, FTIR result showed a metal oxide at a wave number of 590 cm -1 which indicated cobalt ferrite nanoparticles. The crystalline structure was confirmed using x-ray diffraction that the high purity of cobalt ferrite was realized. Calculation of the cation distribution by using comparison I 220 /I 222 and I 422 /I 222 show that the synthesis and annealing temperature succesfully modify cation occupy the site octahedral and tetrahedral. (paper)

  12. Structural characterization of FeVO{sub 4} synthesized by co-precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Bera, Ganesh; Sinha, Sourav; Rambabu, P.; Das, P.; Gupta, A. K.; Turpu, G. R., E-mail: dr.tgreddy@gmail.com [Department of Pure and Applied Physics, Guru Ghasidas Vishwavidyalaya, Koni, Bilaspur 495 009 (India)

    2016-05-06

    A Low temperature method for synthesizing triclinic FeVO{sub 4} nanoparticles is manifested through co-precipitation method. Three precursor materials taken for the synthesis are Iron Nitrate, Ammonium Metavanadate and NaOH along with DI water. The attained precipitate was dried at 100°C for overnight and calcined at different temperatures ranging from 400°C - 650°C. The achieved powdered materials are studied through X-ray diffraction and found to be in pure single phase of P-1 space group symmetry. The crystallite size measured through Scherrer’s method is in found to be in the range of 40-60 nm. Raman spectroscopic studies were carried out at room temperature. Raman spectra is in agreement with the reported structural data of FeVO{sub 4}.

  13. Synthesis of alumina/YAG 20 vol% composite by co-precipitation

    Directory of Open Access Journals (Sweden)

    Radosław Lach

    2011-12-01

    Full Text Available Co-precipitation of alumina/YAG precursor from aluminum and yttrium nitrate solution with ammonium carbonate results in dawsonite. Its crystallographic parameters differ from the compound precipitated with no yttrium additive. It suggests that yttrium ions become incorporated into the dawsonite structure. The DSC/TG and X-ray diffraction measurements show decomposition of dawsonite at elevated temperatures resulting in γ-Al2O3 and then δ- and θ-alumina modifications. Full transformation to α-Al2O3 and YAG occurs at temperatures higher than 1230°C. Starting powder for the sintering experiments was prepared using the coprecipitated precursor calcined at 600°C. Seeding of such powder with 5 wt.% α-Al2O3 results in material of 98% density at 1500°C. Much lower densification show compacts of unseeded powder.

  14. Zirconia-mullite obtained from co-precipitated zirconia-mullite composite powders by SPS

    Energy Technology Data Exchange (ETDEWEB)

    Li, H.Z.; Li, Z.J.; Luo, X.D. [Univ. of Science and Technology Liaoning, Anshan (China). School of High Temperature Materials and Magnesium Resource Engineering; Gui, J.Y.; Xie, Z.P. [Tsinghua Univ., Beijing (China). School of Materials Science and Engineering

    2016-07-01

    The co-precipitation method is used to fabricate precursor powder. This powder is densified by means of the spark plasma sintering (SPS) technique at 1500 C with a holding time of 7 min to prepare zirconia-mullite samples. Their density measures up to 97 % of the theoretical density, and the sintered mullite compacts exhibit better strength properties (289 ± 12 MPa) and H{sub v} (9.99 GPa). The mode of fracture is changed with the addition of ZrO{sub 2} and extensive fine cleavages are observed on the grain surface. These cleavages join together to form steps, which can absorb more energy. The flexural strength of the samples is almost double that of pure mullite, which is related to the formation of cleavages.

  15. Structural variation study of cobalt nanoparticles synthesized by co-precipitation method using 59Co NMR

    Science.gov (United States)

    Manjunatha, M.; Kumar, Rajeev; B. M., Siddesh; Sahoo, Balaram; Damle, R.; Ramesh, K. P.

    2018-04-01

    We have synthesized cobalt nanoparticles using co-precipitation method. Further, the two phases of the cobalt is monitored by varying the synthesis parameters. 59Co NMR and XRD are used as characterization tools to study the phase variation in the cobalt samples. XRD and NMR results show a remarkable correlation in the two samples (Co-1 and Co-2). Co-2 has predominant fcc and hcp phases, whereas, Co-1 has fcc phase with lower amount of hcp. Both the samples show same saturation magnetization (Ms) but there is a remarkable difference in the phase composition. Thus, 59Co NMR appears to be a good tool to identify the phase purity of the ferromagnetic cobalt samples.

  16. Magnetic behavior of nickel ferrite nanoparticles prepared by co-precipitation route

    International Nuclear Information System (INIS)

    Maaz, K.; Mashiatullah, A.; Javed, T.; Ali, G.; Karim, S.

    2008-01-01

    Magnetic nanoparticles of nickel ferrite (NiFe/sub 2/O/sub 4/) have been synthesized by co-precipitation route using stable ferric and nickel salts with sodium hydroxide as the precipitating agent and oleic acid as the surfactant. X-ray Diffraction (XRD) and Transmission Electron Microscope (TEM) analyses confirmed the formation of single phase nickel ferrite nanoparticles in the range 8-28 nm. The size of the particles was observed to be increasing linearly with increasing annealing temperature of the sample. Typical blocking effects were observed below -225 K for all the prepared samples. The superparamagnetic blocking temperature was found to be continuously increasing with increasing particle sizes that has been attributed to the increased effective anisotropy of the nanoparticles. The saturation moment of all the samples was found much below the bulk value of nickel ferrite that has been attributed to the disordered surface spins of these nanoparticles. (author)

  17. Magnetic Properties of Copper Doped Nickel Ferrite Nanoparticles Synthesized by Co Precipitation Method

    Science.gov (United States)

    Anjana, V.; John, Sara; Prakash, Pooja; Nair, Amritha M.; Nair, Aravind R.; Sambhudevan, Sreedha; Shankar, Balakrishnan

    2018-02-01

    Nickel ferrite nanoparticles with copper atoms as dopant have been prepared using co-precipitation method with general formula Ni1-xCuxFe2O4 (x=0.2, 0.4, 0.6, 0.8 and 1) and are sintered at quite ambient temperature. Structural and magnetic properties were examined using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction method (XRD) and Vibrating Sample Magnetometer (VSM) to study the influence of copper doping in nickel ferrite magnetic nanoparticles. X-ray studies proves that the particles are possessing single phase spinel structure with an average particle size calculated using Debye Scherer formula. Magnetic measurements reveal that saturation magnetization value (Ms) decreases while magnetic coercivity (Hc) increases upon doping.

  18. Synthesis and crystal kinetics of cerium oxide nanocrystallites prepared by co-precipitation process

    International Nuclear Information System (INIS)

    Shih, C.J.; Chen, Y.J.; Hon, M.H.

    2010-01-01

    Cerium oxide nanocrystallites were synthesized at a relatively low temperature using cerium nitrate as starting materials in a water solution by a co-precipitation process. Effect of calcination temperature on the crystallite growth of cerium oxide nano-powders was investigated by X-ray diffraction, transmission electron microscopy and electron diffraction. The crystallization temperature of the cerium oxide powders was estimated to be about 273 K by XRD analysis. When calcined from 473 to 1273 K, the crystallization of the face-centered cubic phase was observed by XRD. The crystallite size of the cerium oxide increased from 10.0 to 43.8 nm with calcining temperature increasing from 673 to 1273 K. The activation energy for growth of cerium oxide nanoparticles was found to be 16.0 kJ mol -1 .

  19. Synthesis and crystal kinetics of cerium oxide nanocrystallites prepared by co-precipitation process

    Energy Technology Data Exchange (ETDEWEB)

    Shih, C.J., E-mail: cjshih@kmu.edu.tw [Department of Fragrance and Cosmetics Science, Kaohsiung Medical University, 100 Shi-Chuan 1st Road, Kaohsiung 807, Taiwan (China); Chen, Y.J. [Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Hon, M.H. [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan (China)

    2010-05-15

    Cerium oxide nanocrystallites were synthesized at a relatively low temperature using cerium nitrate as starting materials in a water solution by a co-precipitation process. Effect of calcination temperature on the crystallite growth of cerium oxide nano-powders was investigated by X-ray diffraction, transmission electron microscopy and electron diffraction. The crystallization temperature of the cerium oxide powders was estimated to be about 273 K by XRD analysis. When calcined from 473 to 1273 K, the crystallization of the face-centered cubic phase was observed by XRD. The crystallite size of the cerium oxide increased from 10.0 to 43.8 nm with calcining temperature increasing from 673 to 1273 K. The activation energy for growth of cerium oxide nanoparticles was found to be 16.0 kJ mol{sup -1}.

  20. Superior sinterability of nano-crystalline gadolinium doped ceria powders synthesized by co-precipitation method

    International Nuclear Information System (INIS)

    Hari Prasad, D.; Kim, H.-R.; Park, J.-S.; Son, J.-W.; Kim, B.-K.; Lee, H.-W.; Lee, J.-H.

    2010-01-01

    Reduced sintering temperature of doped ceria can greatly simplify the fabrication process of solid oxide fuel cells (SOFCs) by utilizing the co-firing of all cell components with a single step. In the present study, nano-crystalline gadolinium doped ceria (GDC) powders of high sinterability at lower sintering temperature has been synthesized by co-precipitation at room temperature. The successful synthesis of nano-crystalline GDC was confirmed by XRD, TEM and Raman spectroscopy analysis. Dilatometry studies showed that GDC prepared by this method can be fully densified (97% relative density) at a sintering temperature of 950 o C which is fairly lower than ever before. It has also been found that the sintered samples have a higher ionic conductivity of 1.64 x 10 -2 S cm -1 at 600 o C which is suitable for the intermediate temperature SOFC application.

  1. Co-precipitation and solubility studies of cesium, potassium and sodium tetraphenylborate

    International Nuclear Information System (INIS)

    Peterson, R.A.

    2000-01-01

    This report contains the results from a study requested by High Level Waste on the co-precipitation and solubility of cesium, potassium, and sodium tetraphenylborate. Co-precipitation of cesium (Cs), potassium (K), and sodium (Na) tetraphenylborate (TPB) helps determine the efficiency of reagent usage in the Small Tank Precipitation Process. This process uses NaTPB to remove cesium from waste by means of precipitation. Previous studies by McCabe suggested that if the sodium ion concentration [Na + ] increased the rate at which cesium tetraphenylborate (CsTPB) precipitates also increases. Serkiz also demonstrated that the precipitation of potassium tetraphenylborate (KTPB) in the presence of high [Na + ] (∼5M) appears to produce a mixed solid phase composed of NaTPB and KTPB together in the crystal lattice. In the crystallographic structure of these three tetraphenylborate salts (Cs,K,NaTPB), the tetraphenylborate ion dominates the size of the crystals. Also, note that the three crystals have nearly identical structures with the exception of two additional peaks in the cesium pattern. Given these similarities, TPB precipitation in the presence of Na + , Cs + and K + likely produces an impure isomorphic crystalline mixture of CsTPB, KTPB and NaTPB. The authors speculate that the primary crystalline structure resembles that of KTPB with NaTPB and CsTPB mixed throughout the crystal structure. The precipitation of NaTPB makes some of the anticipated excess tetraphenylborate relatively unavailable for precipitation of cesium. Thus, the amount of excess tetraphenylborate required to completely precipitate all of the potassium and cesium may increase significantly

  2. Nanoscale co-precipitation and mechanical properties of a high-strength low-carbon steel

    International Nuclear Information System (INIS)

    Mulholland, Michael D.; Seidman, David N.

    2011-01-01

    Nanoscale co-precipitation in a novel high-strength low-carbon steel is studied in detail after isothermal aging. Atom-probe tomography is utilized to quantify the co-precipitation of co-located Cu precipitates and M 2 C (M is any combination of Cr, Mo, Fe, or Ti) carbide strengthening precipitates. Coarsening of Cu precipitates is offset by the nucleation and growth of M 2 C carbide precipitate, resulting in the maintenance of a yield strength of 1047 ± 7 MPa (152 ± 1 ksi) for as long as 320 h of aging time at 450 deg. C. Impact energies of 153 J (113 ± 6 ft-lb) and 144 J (106 ± 2 ft-lb) are measured at -30 deg. C and -60 deg. C, respectively. The co-location of Cu and M 2 C carbide precipitates results in non-stationary-state coarsening of the Cu precipitates. Synchrotron-source X-ray diffraction studies reveal that the measured 33% increase in impact toughness after aging for 80 h at 450 deg. C is due to dissolution of cementite, Fe 3 C, which is the source of carbon for the nucleation and growth of M 2 C carbide precipitates. Less than 1 vol.% austenite is observed for aging treatments at temperatures less than 600 deg. C, suggesting that transformation-induced plasticity does not play a significant role in the toughness of specimens aged at temperatures less than 600 deg. C. Aging treatments at temperatures greater than 600 deg. C produce more austenite, in the range 2-7%, but at the expense of yield strength.

  3. Characterization of magnetic nano particles of CoFe{sub 2}O{sub 4} and CoZnFe{sub 2}O{sub 4} prepared by the chemical co-precipitation method; Caracterizacion de nanoparticulas magneticas de CoFe{sub 2}O{sub 4} y CoZnFe{sub 2}O{sub 4} preparadas por el metodo de coprecipitacion quimica

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, J.; Zambrano, G.; Gomez, M. E. [Universidad del Valle, Departamento de Fisica, Laboratorio de Peliculas Delgadas, Ciudad Universitaria Melendez, 25360 Cali (Colombia); Prieto, P. [Universidad del Valle, Centro de Excelencia en Nuevos Materiales, Ciudad Universitaria Melendez, 25360 Cali (Colombia); Espinoza B, F. J., E-mail: javierlo21@gmail.com [IPN, Centro de Investigacion y de Estudios Avanzados, Unidad Queretaro, Libramiento Norponiente No. 2000, Fracc. Real de Juriquilla, 76230 Queretaro (Mexico)

    2012-07-01

    Magnetic cobalt ferrite nanoparticles of CoFe{sub 2}O{sub 4} and CoZnFe{sub 2}O{sub 4} were prepared by co-precipitation technique from aqueous salt solutions of Co (II), ZnSO{sub 4} and Fe (III), in an alkaline medium. CoFe{sub 2}O{sub 4} powder samples were structurally characterized by X-ray diffraction, showing the presence of the most intense peat at 2{theta} = 413928{sup o} (Co K{alpha}1) corresponding to the (311) crystallographic orientation of the CoFe{sub 2}O{sub 4} spinel phase. The mean size of the crystalline of CoFe{sub 2}O{sub 4} and CoZnFe{sub 2}O{sub 4} nanoparticles determined from the full width at half maximum of the strongest reflection of the (311) peak by using the Scherrer approximation was calculated to be 11.4 and 7.0 ({+-} o.2) nm, respectively. Transmission electron microscopy studies permitted determining nanoparticle size of CoZnFe{sub 2}O{sub 4}. Fourier transform infrared spectroscopy was used to confirm the formation of Fe-O bonds, allowing identifying the presence of ferrite spinel structure. Magnetic properties were investigated with the aid of a vibrating sample magnetometer at room temperature Herein, the sample showed superparamagnetic behavior, determined by the hysteresis loop finally, due to the hysteresis loop of the CoZnFe{sub 2}O{sub 4} is very small, our magnetic nanoparticles can be considered as a soft magnetic material. These magnetic nanoparticles have interesting technological applications in biomedicine given their biocompatibility, in nano technology, and in ferro fluid preparation. (Author)

  4. Mechanisms of Se(IV) Co-precipitation with Ferrihydrite at Acidic and Alkaline Conditions and Its Behavior during Aging

    DEFF Research Database (Denmark)

    Francisco, Paul Clarence M.; Sato, Tsutomu; Otake, Tsubasa

    2018-01-01

    in nanopore and defect structures. These results demonstrate a potential long-term immobilization pathway for Se(IV) even after phase transformation. This work presents one of the first direct insights on Se(IV) co-precipitation and its behavior in response to iron phase transformations.......Understanding the form of Se(IV) co-precipitated with ferrihydrite and its subsequent behavior during phase transformation is critical to predicting its long-term fate in a range of natural and engineered settings. In this work, Se(IV)-ferrihydrite co-precipitates formed at different pH were......, Se(IV) was removed dominantly as a ferric selenite-like phase intimately associated with ferrihydrite, while at pH 10, it was mostly present as a surface species on ferrihydrite. Similarly, the behavior of Se(IV) and the extent of its retention during phase transformation varied with pH. At pH 5, Se...

  5. Analysis of decontamination methods used at nuclear power plants and in other facilities. Research report

    International Nuclear Information System (INIS)

    Podlaha, Josef

    2011-10-01

    Methods used in the Czech Republic and in other countries are described. The following topics are treated: Introduction into decontamination; Chemical methods; Foam methods; Electrochemical methods; Mechanical methods; Other methods; Decontamination of civil engineering structures; Technologies suitable for disposal decontamination; and Effect of decontamination on waste management. (P.A.)

  6. The CREATIVE Decontamination Performance Evaluation Model

    National Research Council Canada - National Science Library

    Shelly, Erin E

    2008-01-01

    The project objective is to develop a semi-empirical, deterministic model to characterize and predict laboratory-scale decontaminant efficacy and hazards for a range of: chemical agents (current focus on HD...

  7. Decontaminating products for routine decontamination in nuclear power plants

    International Nuclear Information System (INIS)

    Henning, K.

    2001-01-01

    Routine decontamination work that has to be carried out in practical operation includes the cleaning of all kinds of surfaces such as floors, walls and apparatus, the decontamination of professional clothes and of the personnel. In order to ensure a trouble-free functioning of plants for the treatment of waste water and concentrate in nuclear power plants, radioactive liquid wastes appearing in the controlled area should be compatible with the treatment methods in practice. Radioactive concentrates and resides obtained from the treatment methods are mixed with matrix materials like cement or bitumen or treated by roller frame drying and thus are conditioned for intermediate or final storage. Several requirements should be made on decontaminating agents used in the controlled area. Some of these physical-chemical criteria will be described in detail. (R.P.)

  8. Decontamination manual of RI handling laboratory

    International Nuclear Information System (INIS)

    Wadachi, Yoshiki

    2004-01-01

    Based on experiences in Japan Atomic Energy Research Institute (JAERI), the essential and practical knowledge of radioactive contamination and its decontamination, and the method and procedure of floor decontamination are described for researcher and managing person in charge of handling radioisotopes (RI) in RI handling laboratories. Essential knowledge concerns the uniqueness of solid surface contamination derived from RI half lives and quantities, surface contamination density limit, and mode/mechanism of contamination. The principle of decontamination is a single conduct with recognition of chemical form of the RI under use. As the practical knowledge, there are physical and chemical methods of solid surface decontamination. The latter involves use of inorganic acids, chelaters and surfactants. Removal and replacement of contaminated solid like floor material are often effective. Distribution mapping of surface contamination can be done by measuring the radioactivity in possibly contaminated areas, and is useful for planning of effective decontamination. Floor surface decontamination is for the partial and spread areas of the floor. It is essential to conduct the decontamination with reagent from the highly to less contaminated areas. Skin decontamination with either neutral detergent or titanium oxide is also described. (N.I.)

  9. CB decontamination for first responders

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, M.D.G.; Purdon, J.G.; Burczyk, A. [Defence Research and Development Canada Suffield, Ralston, AB (Canada)

    2006-07-01

    The Universal Containment System (UCS) is designed to contain, mitigate and decontaminate chemical, biological and radiological warfare agents. The UCS consists of a lightweight, tent-like enclosure filled with a water-based surface decontaminating foam (SDF). The Canadian government funded a project to advance the understanding of the behaviour of the UCS. This paper described the success of the project as well as the technological advances in the UCS formulation and equipment. Vapour desorption experiments were conducted in which SDF was applied onto 12 surfaces found in a typical office environment. Both mustard and nerve agent were studied on the test surfaces. Both scrubbing and non-scrubbing decontamination methods were tested. SDF effectively decontaminated the non-porous substances, particularly when the scrubbing procedure was used. Results were more complicated for the non-porous samples. A dye added to the agent was useful for determining the fate of the agent. Liquid phase studies were conducted in which the reaction between SDF and various agents were studied in the liquid phase in order to estimate the rate of reaction, the stoichiometry and the reaction products formed. Both SDF and the commercial decontamination agent CASCAD were found to effectively kill 100 per cent of anthrax spores. The significance of this project to first responders was considerable. Changes to the formulation and equipment of UCS will increase its usefulness and safety. Users will also have a better knowledge of the amount of decontamination needed for complete effectiveness in specific situations. Recommendations have been made for use of the product on a range of indoor surfaces. Field trials have shown the blast mitigation and agent decontamination ability of the foam under explosive situations. 15 refs., 4 tabs.

  10. Sterilization and Decontamination of Surfaces Contaminated With Biological and Chemical Warfare Agents Using Atmospheric Pressure Plasma Discharges

    National Research Council Canada - National Science Library

    Garate, Eusebio

    1999-01-01

    ... based on the application of an atmospheric pressure plasma. We used both a DC corona and dielectric barrier discharge for the sterilization tests which were conducted on a variety of substrates including metals and chemically resistant fabrics...

  11. Precipitation process for supernate decontamination

    International Nuclear Information System (INIS)

    Lee, L.M.; Kilpatrick, L.L.

    1982-11-01

    A precipitation and adsorption process has been developed to remove cesium, strontium, and plutonium from water-soluble, high-level radioactive waste. An existing waste tank serves as the reaction vessel and the process begins with the addition of a solution of sodium tetraphenylborate and a slurry of sodium titanate to the contained waste salt solution. Sodium tetraphenylborate precipitates the cesium and sodium titanate adsorbs the strontium and plutonium. The precipitate/adsorbate is then separated from the decontaminated salt solution by crossflow filtration. This new process offers significant capital savings over an earlier ion exchange process for salt decontamination. Chemical and small-scale engineering studies with actual waste are reported. The effect of many variables on the decontamination factors and filter performance are defined

  12. Co-precipitation of plutonium(IV) and americium(III) from nitric acid-oxalic acid solutions with bismuth oxalate

    International Nuclear Information System (INIS)

    Pius, I.C.; Noronha, D.M.; Chaudhury, Satyajeet

    2017-01-01

    Co-precipitation of plutonium and americium from nitric acid-oxalic acid solutions with bismuth oxalate has been investigated for the removal of these long lived α-active nuclides from waste solutions. Effect of concentration of bismuth and oxalic acid on the co-precipitation of Pu(IV) from 3 M HNO_3 has been investigated. Similar experiments were also carried out from 3.75 M HNO_3 on co-precipitation of Am(III) to optimize the conditions of precipitation. Strong co-precipitation of Pu(IV) and Am(III) with bismuth oxalate indicate feasibility of treatment of plutonium and americium bearing waste solutions. (author)

  13. Full system decontamination feasibility studies

    International Nuclear Information System (INIS)

    Denault, R.P.; LeSurf, J.E.; Walschot, F.W.

    1988-01-01

    Many chemical decontaminations have been performed on subsystems in light water reactors (BWRs and PWRs) but none on the full system (including the fuel) of large, (>500 MWe) investor owned reactors. Full system decontaminations on pressure-tubed reactors have been shown to facilitate maintenance, inspection, repair and replacement of reactor components. Further advantages are increased reactor availability and plant life extension. A conceptual study has been performed for EPRI (for PWRs) and Commonwealth Edison Co (for BWRs) into the applicability and cost benefit of full system decontaminations (FSD). The joint study showed that FSDs in both PWRs and BWRs, with or without the fuel included in the decontamination, are feasible and cost beneficial provided a large amount of work is to be done following the decontamination. The large amounts of radioactive waste generated can be managed using current technologies. Considerable improvements in waste handling, and consequent cost savings, can be obtained if new techniques which are now reaching commercial application are used. (author)

  14. Synthesis of YAG nanopowder by the co-precipitation method: Influence of pH and study of the reaction mechanisms

    Science.gov (United States)

    Marlot, Caroline; Barraud, Elodie; Le Gallet, Sophie; Eichhorn, Marc; Bernard, Frédéric

    2012-07-01

    YAG nanopowders with an average grain size of 30 nm have been successfully synthesized by the co-precipitation method using nitrates with precipitant of ammonium hydrogen carbonate. The influence of precipitation conditions such as pH, aging time and calcination temperature on the formation of secondary phases has been studied. The accurate control of pH value at every stage of precipitation process is crucial to avoid the presence of YAM (Yttrium Aluminium Monoclinic, Y4Al2O9) and yttrium oxide (Y2O3) after calcination. The reaction mechanisms have been investigated using different techniques such as infrared spectroscopy, x-ray diffraction and thermal analyses. The YAG phase is formed around 1050 °C passing through an intermediate phase called YAP (Yttrium Aluminium Perovskite, YAlO3). Local chemical heterogeneities are responsible for the deviation of the Y:Al ratio and the formation of YAP during heat treatment.

  15. Preparation of magnetic albumin nanoparticles via a simple and one-pot desolvation and co-precipitation method for medical and pharmaceutical applications.

    Science.gov (United States)

    Nosrati, Hamed; Salehiabar, Marziyeh; Manjili, Hamidreza Kheiri; Danafar, Hossein; Davaran, Soodabeh

    2018-03-01

    In this study, iron oxide magnetic bovine serum albumin core-shell nanoparticles (BSA coated IONPs) with narrow particle size distribution were synthesized under one-pot reaction via the desolvation and chemical co-precipitation method. Functionalized IONPs were characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM) techniques. Furthermore, vibrating sample magnetometer (VSM) analysis show these nanoparticles (NPs) have an excellent magnetic properties. Cellular toxicity of IONPs was also investigated on HFF2 cell lines. Additionally, a hemolysis test of as prepared core-shell NPs were performed. The presence of albumin as a biomolecule coating on the surface of IONPs showed an improving effect to reduce the cytotoxicity. The properties of the designed NPs propose the BSA coated IONPs as a promising candidate for multifunctional biomedical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Structure and magnetic properties of Mg0.35Cu0.2Zn0.45Fe2O4 ferrite synthesized by co-precipitation method

    Directory of Open Access Journals (Sweden)

    Bo Yang

    2017-05-01

    Full Text Available Mg0.35Cu0.2Zn0.45Fe2O4 nanosize particles have been synthesized by chemical co-precipitation method and characterized by X-ray diffraction (XRD and vibrating sample magnetometry (VSM. The XRD patterns confirmed the single phase spinel structure of the synthesized powder. The average crystallite size of the powder varied from 14 to 55 nm by changing annealing temperature. The activation energy for crystal growth was estimated as about 18.61KJ/mol. With the annealing temperature increasing, saturation magnetization (MS was successively increased while the coercivity (HC was first increased, passed through a maximum and then declined. The sintering temperature has significant influence on bulk density, initial permeability and Curie temperature of Mg0.35Cu0.2Zn0.45Fe2O4 ferrite.

  17. Decontamination Technology Development for Nuclear Research Facilities

    International Nuclear Information System (INIS)

    Oh, Won Zin; Jung, Chong Hun; Choi, Wang Kyu; Won, Hui Jun; Kim, Gye Nam

    2004-02-01

    Technology development of surface decontamination in the uranium conversion facility before decommissioning, technology development of component decontamination in the uranium conversion facility after decommissioning, uranium sludge treatment technology development, radioactive waste soil decontamination technology development at the aim of the temporary storage soil of KAERI, Optimum fixation methodology derivation on the soil and uranium waste, and safety assessment methodology development of self disposal of the soil and uranium waste after decontamination have been performed in this study. The unique decontamination technology applicable to the component of the nuclear facility at room temperature was developed. Low concentration chemical decontamination technology which is very powerful so as to decrease the radioactivity of specimen surface under the self disposal level was developed. The component decontamination technology applicable to the nuclear facility after decommissioning by neutral salt electro-polishing was also developed. The volume of the sludge waste could be decreased over 80% by the sludge waste separation method by water. The electrosorption method on selective removal of U(VI) to 1 ppm of unrestricted release level using the uranium-containing lagoon sludge waste was tested and identified. Soil decontamination process and equipment which can reduce the soil volume over 90% were developed. A pilot size of soil decontamination equipment which will be used to development of real scale soil decontamination equipment was designed, fabricated and demonstrated. Optimized fixation methodology on soil and uranium sludge was derived from tests and evaluation of the results. Safety scenario and safety evaluation model were development on soil and uranium sludge aiming at self disposal after decontamination

  18. Heavy metal immobilization via microbially induced carbonate precipitation and co-precipitation

    Science.gov (United States)

    Lauchnor, E. G.; Stoick, E.

    2017-12-01

    Microbially induced CaCO3 precipitation (MICP) has been successfully used in applications such as porous media consolidation and sealing of leakage pathways in the subsurface, and it has the potential to be used for remediation of metal and radionuclide contaminants in surface and groundwater. In this work, MICP is investigated for removal of dissolved heavy metals from contaminated mine discharge water via co-precipitation in CaCO3 or formation of other metal carbonates. The bacterially catalyzed hydrolysis of urea produces inorganic carbon and ammonium and increases pH and the saturation index of carbonate minerals to promote precipitation of CaCO3. Other heavy metal cations can be co-precipitated in CaCO3 as impurities or by replacing Ca2+ in the crystal lattice. We performed laboratory batch experiments of MICP in alkaline mine drainage sampled from an abandoned mine site in Montana and containing a mixture of heavy metals at near neutral pH. Both a model bacterium, Sporosarcina pasteurii, and a ureolytic bacterium isolated from sediments on the mine site were used to promote MICP. Removal of dissolved metals from the aqueous phase was determined via inductively coupled plasma mass spectrometry and resulting precipitates were analyzed via electron microscopy and energy dispersive x-ray spectroscopy (EDX). Both S. pasteurii and the native ureolytic isolate demonstrated ureolysis, increased the pH and promoted precipitation of CaCO3 in batch tests. MICP by the native bacterium reduced concentrations of the heavy metals zinc, copper, cadmium, nickel and manganese in the water. S. pasteurii was also able to promote MICP, but with less removal of dissolved metals. Analysis of precipitates revealed calcium carbonate and phosphate minerals were likely present. The native isolate is undergoing identification via 16S DNA sequencing. Ongoing work will evaluate biofilm formation and MICP by the isolate in continuous flow, gravel-filled laboratory columns. This research

  19. Encapsulation of albumin in self-assembled layer-by-layer microcapsules: comparison of co-precipitation and adsorption techniques.

    Science.gov (United States)

    Labala, Suman; Mandapalli, Praveen Kumar; Bhatnagar, Shubhmita; Venuganti, Venkata Vamsi Krishna

    2015-01-01

    The objective of this study is to prepare and characterize polymeric self-assembled layer-by-layer microcapsules (LbL-MC) to deliver a model protein, bovine serum albumin (BSA). The aim is to compare the BSA encapsulation in LbL-MC using co-precipitation and adsorption methods. In co-precipitation method, BSA was co-precipitated with growing calcium carbonate particles to form a core template. Later, poly(styrene sulfonate) and poly(allylamine hydrochloride) were sequentially adsorbed onto the CaCO3 templates. In adsorption method, preformed LbL-MC were incubated with BSA and encapsulation efficiency is optimized for pH and salt concentration. Free and BSA-encapsulated LbL-MC were characterized using Zetasizer, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy and differential scanning calorimeter. Later, in vitro release studies were performed using dialysis membrane method at pH 4, 7.4 and 9. Results from Zetasizer and SEM showed free LbL-MC with an average size and zeta-potential of 2.0 ± 0.6 μm and 8.1 ± 1.9 mV, respectively. Zeta-potential of BSA-loaded LbL-MC was (-)7.4 ± 0.7 mV and (-)5.7 ± 1.0 mV for co-precipitation and adsorption methods, respectively. In adsorption method, BSA encapsulation in LbL-MC was found to be greater at pH 6.0 and 0.2 M NaCl. Co-precipitation method provided four-fold greater encapsulation efficiency (%) of BSA in LbL-MC compared with adsorption method. At pH 4, the BSA release from LbL-MC was extended up to 120 h. Polyacrylamide gel electrophoresis showed that BSA encapsulated in LBL-MC through co-precipitation is stable toward trypsin treatment. In conclusion, co-precipitation method provided greater encapsulation of BSA in LbL-MC. Furthermore, LbL-MC can be developed as carriers for pH-controlled protein delivery.

  20. Suitability of Sr{sub 0.5}Ba{sub 0.5-x}Ce{sub x}Fe{sub 12-y}Ni{sub y}O{sub 19} co-precipitated nanomaterials for inductor applications

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, Muhammad Javed, E-mail: mjiqauchem@yahoo.co [Surface and Solid State Chemistry Laboratory, Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Farooq, Saima [Surface and Solid State Chemistry Laboratory, Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

    2010-03-18

    The present investigation deals with the synthesis and characterization of Ce-Ni ions substituted nanocrystalline strontium-barium hexaferrites (Sr{sub 0.5}Ba{sub 0.5}Fe{sub 12}O{sub 19}) by the chemical co-precipitation method, with focus on the optimization of annealing temperature for the hexagonal phase development. The synthesis involves co-precipitation of aqueous solutions of water-soluble salts of strontium, barium and iron, at pH 9 using an ammonium hydroxide solution as a precipitating agent. The optimum temperature of annealing, necessary for the hexagonal phase development, is determined on the basis of thermo-gravimetric analysis (TGA). The co-precipitate is annealed at a temperature of 1323 K for 6 h, to produce a single magnetoplumbite phase of Sr-Ba hexaferrites, with the corresponding average crystallite size ranging from 36 to 48 nm. Observed changes in the lattice structure determined by the powder X-ray diffraction (XRD) studies are not in contradiction with the results of TGA. DC-electrical resistivity increases from 1.8 x 10{sup 10} to 12.5 x 10{sup 10} {Omega} cm, whereas the drift mobility, dielectric constant and dielectric loss tangent decrease with increasing the Ce-Ni content of the samples. Material of above-mentioned characteristics is considered to be suitable for applications in the microwave and surface mount devices (SMD) for fabricating the multilayer chip inductors (MLCI).

  1. Effect of Calcination at Synthesis of Mg-Al Hydrotalcite Using co-Precipitation Method

    Directory of Open Access Journals (Sweden)

    Niar Kurnia Julianti

    2017-01-01

    Full Text Available The use of hydrotalcite in catalysis has wide attention in academic research and industrial parties. Based on its utilization, hydrotalcite can be active catalyst or support. This research is focused on the investigation of characteristic like spesific surface area of Mg-Al hydrotalcite which is prepared with different temperature of calcination. Synthesis of Mg-Al hydrotalcites with Mg/Al molar ratio 3:1 were prepared by co-precipitation method. Mg(NO33.6H2O and Al(NO33.9H2O as precursors of Mg-Al hydrotalcite. Na2CO3 was used as precipitant agent and NaOH was used as buffer solution. The solution was mixed and aging for 5 hours at 650oC. The dried precipitate was calcined at 2500oC, 3500oC, 4500oC, 5500oC and 6500oC. The characterization of functional group was determined by Fourier Transform Infra Red (FT-IR. The Identical peaks diffractogram were analyzed by X-Ray Diffraction (XRD. The spesific surface area was determined by adsorption-desorption of nitrogen. The largest surface area that obtained from the calcination temperature of 650oC is 156.252 m2/g.

  2. Structural Characterization of Polymer-Clay Nanocomposites Prepared by Co-Precipitation Using EPR Techniques

    Directory of Open Access Journals (Sweden)

    Udo Kielmann

    2014-02-01

    Full Text Available Polymer-clay nanocomposites (PCNCs containing either a rubber or an acrylate polymer were prepared by drying or co-precipitating polymer latex and nanolayered clay (synthetic and natural suspensions. The interface between the polymer and the clay nanoparticles was studied by electron paramagnetic resonance (EPR techniques by selectively addressing spin probes either to the surfactant layer (labeled stearic acid or the clay surface (labeled catamine. Continuous-wave (CW EPR studies of the surfactant dynamics allow to define a transition temperature T* which was tentatively assigned to the order-disorder transition of the surfactant layer. CW EPR studies of PCNC showed that completely exfoliated nanoparticles coexist with agglomerates. HYSCORE spectroscopy in PCNCs showed couplings within the probe −assigned with DFT computations− and couplings with nuclei of the environment, 1H and 23Na for the surfactant layer probe, and 29Si, 7Li, 19F and 23Na for the clay surface probe. Analysis of these couplings indicates that the integrity of the surfactant layer is conserved and that there are sizeable ionic regions containing sodium ions directly beyond the surfactant layer. Simulations of the very weak couplings demonstrated that the HYSCORE spectra are sensitive to the composition of the clay and whether or not clay platelets stack.

  3. Fabrication of Tb3Al5O12 transparent ceramics using co-precipitated nanopowders

    Science.gov (United States)

    Dai, Jiawei; Pan, Yubai; Wang, Wei; Luo, Wei; Xie, Tengfei; Kou, Huamin; Li, Jiang

    2017-11-01

    Terbium aluminum garnet (TAG) precursor was synthesized by a co-precipitation method from a mixed solution of terbium and aluminum nitrates using ammonium hydrogen carbonate (AHC) as the precipitant. The powders calcined at different temperatures were investigated by XRD, FTIR and FESEM in order to choose the optimal calcination temperature. Fine and low-agglomerated TAG powders with average particle size of 88 nm were obtained by calcining the precursor at 1100 °C for 4 h. Using this powder as starting material, TAG transparent ceramics were fabricated by vacuum sintering combined with hot isostatic pressing (HIP) sintering. For the sample pre-sintered at 1700 °C for 20 h with HIP post-treated at 1700 °C for 3 h, the average grain size is about 3.9 μm and the in-line transmittance is beyond 55% in the region of 500-1600 nm, reaching a maximum transmittance of 64.2% at the wavelength of 1450 nm. The Verdet constant at 633 nm is measured to be -178.9 rad T-1 m-1, which is 33% larger than that of the commercial TGG single crystal (-134 rad T-1 m-1).

  4. Neptunium sorption and co-precipitation of strontium in simulated DWPF salt solution

    International Nuclear Information System (INIS)

    McIntyre, P.F.; Orebaugh, E.G.; King, C.M.

    1988-01-01

    Batch experiments performed using crushed slag saltstone (∼40 mesh) removed >80% of 237 Np from simulated Defense Waste Processing Facility (DWPF) salt solution. The concentration of 237 Np (110 pCi/ml) used was 1000x greater than levels in actual DWPF solutions. Neptunium-239 was used as a tracer and was formed by neutron activation of uranyl nitrate. Results showed that small amounts of crushed saltstone (as little as 0.05 grams), removed >80% of neptunium from 15 ml of simulated DWPF solution after several hours equilibration. The neptunium is sorbed on insoluble carbonates formed in and on the saltstone matrix. Further testing showed that addition of 0.01 and 0.10 ml of 1 molar Ca +2 (ie. Ca (NO 3 ) 2 , CaCl 2 ) into 15 ml of simulated DWPF solution yielded a white carbonate precipitate which also removed >80% of the neptunium after 1 hour equilibration. Further experiments were performed to determine the effectiveness of this procedure to co-precipitate strontium

  5. Uranium (III)-Plutonium (III) co-precipitation in molten chloride

    Science.gov (United States)

    Vigier, Jean-François; Laplace, Annabelle; Renard, Catherine; Miguirditchian, Manuel; Abraham, Francis

    2018-02-01

    Co-management of the actinides in an integrated closed fuel cycle by a pyrochemical process is studied at the laboratory scale in France in the CEA-ATALANTE facility. In this context the co-precipitation of U(III) and Pu(III) by wet argon sparging in LiCl-CaCl2 (30-70 mol%) molten salt at 705 °C is studied. Pu(III) is prepared in situ in the molten salt by carbochlorination of PuO2 and U(III) is then introduced as UCl3 after chlorine purge by argon to avoid any oxidation of uranium up to U(VI) by Cl2. The oxide conversion yield through wet argon sparging is quantitative. However, the preferential oxidation of U(III) in comparison to Pu(III) is responsible for a successive conversion of the two actinides, giving a mixture of UO2 and PuO2 oxides. Surprisingly, the conversion of sole Pu(III) in the same conditions leads to a mixture of PuO2 and PuOCl, characteristic of a partial oxidation of Pu(III) to Pu(IV). This is in contrast with coconversion of U(III)-Pu(III) mixtures but in agreement with the conversion of Ce(III).

  6. Synthesis and magnetic characterization of nickel ferrite nanoparticles prepared by co-precipitation route

    Science.gov (United States)

    Maaz, K.; Karim, S.; Mumtaz, A.; Hasanain, S. K.; Liu, J.; Duan, J. L.

    2009-06-01

    Magnetic nanoparticles of nickel ferrite (NiFe 2O 4) have been synthesized by co-precipitation route using stable ferric and nickel salts with sodium hydroxide as the precipitating agent and oleic acid as the surfactant. X-ray diffraction (XRD) and transmission electron microscope (TEM) analyses confirmed the formation of single-phase nickel ferrite nanoparticles in the range 8-28 nm depending upon the annealing temperature of the samples during the synthesis. The size of the particles ( d) was observed to be increasing linearly with annealing temperature of the sample while the coercivity with particle size goes through a maximum, peaking at ˜11 nm and then decreases for larger particles. Typical blocking effects were observed below ˜225 K for all the prepared samples. The superparamagnetic blocking temperature ( T B) was found to be increasing with increasing particle size that has been attributed to the increased effective anisotropy energy of the nanoparticles. The saturation moment of all the samples was found much below the bulk value of nickel ferrite that has been attributed to the disordered surface spins or dead/inert layer in these nanoparticles.

  7. Effect of synthesis conditions on the preparation of YIG powders via co-precipitation method

    International Nuclear Information System (INIS)

    Rashad, M.M.; Hessien, M.M.; El-Midany, A.; Ibrahim, I.A.

    2009-01-01

    Yttrium iron garnet (YIG) (Y 3 Fe 5 O 12 ) powders have been synthesized through a co-precipitation method in the presence of sodium bis(2-ethylhexylsulfosuccinate), AOT as an anionic surfactant. The garnet precursors produced were obtained from aqueous iron and yttrium nitrates mixtures using 5 M sodium hydroxide at pH 10. A statistical Box-Behnken experimental design was used to investigate the effect of the main parameters (i.e. AOT surfactant concentration, annealing time and temperature) on YIG powder formation, crystallite size, morphology and magnetic properties. YIG particles were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and vibrating sample magnetometer. XRD revealed that the formation of single cubic phase of YIG was temperature dependent and increased by increasing the annealing temperature from 800 to 1200 o C. SEM micrographs showed that the addition of AOT surfactant promoted the microstructure of YIG in crystalline cubic-like structure. The magnetic properties were sensitive to the synthesis variables of annealing temperature, time and AOT surfactant concentration. The maximum saturation magnetization (28.13 emu/g), remanence magnetization (21.57 emu/g) and coercive force (703 Oe) were achieved at an annealing temperature of 1200 o C, time 2 h and 500 ppm of AOT surfactant concentration.

  8. MOFabric: Electrospun Nanofiber Mats from PVDF/UiO-66-NH2 for Chemical Protection and Decontamination.

    Science.gov (United States)

    Lu, Annie Xi; McEntee, Monica; Browe, Matthew A; Hall, Morgan G; DeCoste, Jared B; Peterson, Gregory W

    2017-04-19

    Textiles capable of capture and detoxification of toxic chemicals, such as chemical-warfare agents (CWAs), are of high interest. Some metal-organic frameworks (MOFs) exhibit superior reactivity toward CWAs. However, it remains a challenge to integrate powder MOFs into engineered materials like textiles, while retaining functionalities like crystallinity, adsorptivity, and reactivity. Here, we present a simple method of electrospinning UiO-66-NH 2 , a zirconium MOF, with polyvinylidene fluoride (PVDF). The electrospun composite, which we refer to as "MOFabric", exhibits comparable crystal patterns, surface area, chlorine uptake, and simulant hydrolysis to powder UiO-66-NH 2 . The MOFabric is also capable of breaking down GD (O-pinacolyl methylphosphonofluoridae) faster than powder UiO-66-NH 2. Half-life of GD monitored by solid-state NMR for MOFabric is 131 min versus 315 min on powder UiO-66-NH 2 .

  9. Experience in decontamination of the equipment of NPP's with the WWER-440 reactors

    International Nuclear Information System (INIS)

    Balaban-Irmenin, Yu.V.

    1981-01-01

    Different methods of decontamination at NPPs are briefly characterized. Decontamination of the removable part of the main circulation pump (MCP) of the WWER-440 reactor is considered as an example of removable equipment decontamination. A design of the decontamination bath of the removable MCP elements and the applied chemical agents are described. A decontamination flowsheet of the Novovoronezh NPP steam generator (SG) is considered as an example of the autonomic decontamination system. The SG decontamination modes, principal flowsheets of a hydromonitor, steam-ejection sprayer and steam-emulsion device are described [ru

  10. Criteria and evaluation of three decontamination techniques

    Energy Technology Data Exchange (ETDEWEB)

    Tripp, J.L.

    1994-01-01

    Past decontamination and solvent recovery activities at the Idaho Chemical Processing Plant (ICPP), which is part of the Idaho National Engineering Laboratory (INEL), have resulted in the accumulation of 1.5 million gallons of radioactively contaminated sodium-bearing liquid waste. Future decontamination activities at the ICPP could result in the production of 5 million gallons or more of sodium-bearing waste using the current decontamination techniques of chemical/water flushes and steam jet cleaning. This waste requires a large amount of cold chemical additive to process because the low melting temperatures of sodium and potassium salts cause agglomeration in the bed of the calciner vessel. Criteria have been established for evaluating methods and technologies available for decontaminating equipment and facilities. The criteria were weighted according to their relative importance using a Kepner-Tregoe Problem Solving process. These criteria were used to rank three decontamination techniques new to the ICPP: laser ablation, liquid abrasive blasting and CO{sub 2} pellet blasting, against the standard decontamination techniques of sodium-based chemical cleaning and water/steam jets used.

  11. Criteria and evaluation of three decontamination techniques

    International Nuclear Information System (INIS)

    Tripp, J.L.

    1994-01-01

    Past decontamination and solvent recovery activities at the Idaho Chemical Processing Plant (ICPP), which is part of the Idaho National Engineering Laboratory (INEL), have resulted in the accumulation of 1.5 million gallons of radioactively contaminated sodium-bearing liquid waste. Future decontamination activities at the ICPP could result in the production of 5 million gallons or more of sodium-bearing waste using the current decontamination techniques of chemical/water flushes and steam jet cleaning. This waste requires a large amount of cold chemical additive to process because the low melting temperatures of sodium and potassium salts cause agglomeration in the bed of the calciner vessel. Criteria have been established for evaluating methods and technologies available for decontaminating equipment and facilities. The criteria were weighted according to their relative importance using a Kepner-Tregoe Problem Solving process. These criteria were used to rank three decontamination techniques new to the ICPP: laser ablation, liquid abrasive blasting and CO 2 pellet blasting, against the standard decontamination techniques of sodium-based chemical cleaning and water/steam jets used

  12. Foam process for application of decontamination agents

    International Nuclear Information System (INIS)

    Harris, J.M.; Miller, J.R.; Frazier, R.S.; Walter, J.H.

    1982-01-01

    This paper presents the results and observations of a study performed by the authors to parametrically evaluate the performance characteristics of a foam process for application of decontamination agents. The initial tests were established to assess foam quality. Subsequent tests determined the ability of the foam as a carrier of chemical systems, and established system operating parameters. The technique was then applied in an actual decontamination task to verify effectiveness of these established parameters and to determine decontamination reduction factors. 4 figures, 5 tables

  13. Decontamination of CANDU primary coolant system

    International Nuclear Information System (INIS)

    Pettit, P.J.

    1975-01-01

    Decontamination of radioactive systems is necessary to reduce personnel radiation exposures and also to reduce exposure during special work. Mechanical decontamination methods are sometimes useful, but most contaminated surfaces are inaccessible, so chemical decontamination often is preferred. The A-P Citrox method will remove most contaminants from CANDU systems, but is costly and long, damages components, and produces large quantities of radioactive liquid waste. The Redox cycling process is fast and inexpensive, produces only solid wastes, but removes small quantities of deposit from Monel only. The CAN-DECON process removes deposits from most materials including fuel cladding and has many other advantages. (author)

  14. Arsenic Removal from Groundwater by Solar Driven Inline-Electrolytic Induced Co-Precipitation and Filtration—A Long Term Field Test Conducted in West Bengal

    Science.gov (United States)

    Malakar, Pradyut; Jana, Bana Bihari; Benz, Florian; Goldmaier, Alexander; Feistel, Ulrike; Jana, Joydev; Lahiri, Susmita; Alvarez, Juan Antonio

    2017-01-01

    Arsenic contamination in drinking water resources is of major concern in the Ganga delta plains of West Bengal in India and Bangladesh. Here, several laboratory and field studies on arsenic removal from drinking water resources were conducted in the past and the application of strong-oxidant-induced co-precipitation of arsenic on iron hydroxides is still considered as the most promising mechanism. This paper suggests an autonomous, solar driven arsenic removal setting and presents the findings of a long term field test conducted in West Bengal. The system applies an inline-electrolytic cell for in situ chlorine production using the natural chloride content of the water and by that substituting the external dosing of strong oxidants. Co-precipitation of As(V) occurs on freshly formed iron hydroxide, which is removed by Manganese Greensand Plus® filtration. The test was conducted for ten months under changing source water conditions considering arsenic (187 ± 45 µg/L), iron (5.5 ± 0.8 mg/L), manganese (1.5 ± 0.4 mg/L), phosphate (2.4 ± 1.3 mg/L) and ammonium (1.4 ± 0.5 mg/L) concentrations. Depending on the system setting removal rates of 94% for arsenic (10 ± 4 µg/L), >99% for iron (0.03 ± 0.03 mg/L), 96% for manganese (0.06 ± 0.05 mg/L), 72% for phosphate (0.7 ± 0.3 mg/L) and 84% for ammonium (0.18 ± 0.12 mg/L) were achieved—without the addition of any chemicals/adsorbents. Loading densities of arsenic on iron hydroxides averaged to 31 µgAs/mgFe. As the test was performed under field conditions and the here proposed removal mechanisms work fully autonomously, it poses a technically feasible treatment alternative, especially for rural areas. PMID:28974053

  15. Arsenic Removal from Groundwater by Solar Driven Inline-Electrolytic Induced Co-Precipitation and Filtration-A Long Term Field Test Conducted in West Bengal.

    Science.gov (United States)

    Otter, Philipp; Malakar, Pradyut; Jana, Bana Bihari; Grischek, Thomas; Benz, Florian; Goldmaier, Alexander; Feistel, Ulrike; Jana, Joydev; Lahiri, Susmita; Alvarez, Juan Antonio

    2017-10-02

    Arsenic contamination in drinking water resources is of major concern in the Ganga delta plains of West Bengal in India and Bangladesh. Here, several laboratory and field studies on arsenic removal from drinking water resources were conducted in the past and the application of strong-oxidant-induced co-precipitation of arsenic on iron hydroxides is still considered as the most promising mechanism. This paper suggests an autonomous, solar driven arsenic removal setting and presents the findings of a long term field test conducted in West Bengal. The system applies an inline-electrolytic cell for in situ chlorine production using the natural chloride content of the water and by that substituting the external dosing of strong oxidants. Co-precipitation of As(V) occurs on freshly formed iron hydroxide, which is removed by Manganese Greensand Plus ® filtration. The test was conducted for ten months under changing source water conditions considering arsenic (187 ± 45 µg/L), iron (5.5 ± 0.8 mg/L), manganese (1.5 ± 0.4 mg/L), phosphate (2.4 ± 1.3 mg/L) and ammonium (1.4 ± 0.5 mg/L) concentrations. Depending on the system setting removal rates of 94% for arsenic (10 ± 4 µg/L), >99% for iron (0.03 ± 0.03 mg/L), 96% for manganese (0.06 ± 0.05 mg/L), 72% for phosphate (0.7 ± 0.3 mg/L) and 84% for ammonium (0.18 ± 0.12 mg/L) were achieved-without the addition of any chemicals/adsorbents. Loading densities of arsenic on iron hydroxides averaged to 31 µgAs/mgFe. As the test was performed under field conditions and the here proposed removal mechanisms work fully autonomously, it poses a technically feasible treatment alternative, especially for rural areas.

  16. Decontamination Technology Development for Nuclear Research Facilities

    International Nuclear Information System (INIS)

    Choi, W. K.; Jung, C. H.; Oh, W. Z.

    2007-06-01

    The originative CO 2 pellet blasting equipment was developed by improving additional components such as feed screw, idle roller and air-lock feeder to clear up the problems of freezing and discontinuity of blasting and by adopting pneumatically operated vacuum suction head and vacuum cup to prevent recontamination by collecting contaminant particulates simultaneously with the decontamination. The optimum decontamination process was established according to the kind of materials such as metal, concrete and plastic and the type of contaminants such as particulate, fixed chemical compound and oil. An excellent decontamination performances were verified by means of the lab-scale hot test with radioactive specimen and the technology demonstration in IMEF hot cell. The PFC dry decontamination equipment applicable to the surface contaminated with high radioactive particulate was developed. This equipment consists of the unit processes such as spray, collection, filtration and dry distillation designed originatively applicable to inside of dry hot cell. Through the demonstration of PFC spray decontamination process in IMEF hot cell, we secured on-site applicability and the decontamination efficiency more than 90 %. We investigated the characteristics of dismantled metal waste melting and the radionuclide(Co, Cs, U) distribution into ingot and slag by melting decontamination experiments using electric arc melter. We obtained the decontamination factors greater than 100 for Cs and of 10∼100 for uranium. The pilot scale(200 kg/batch) demonstration for melting decontamination was carried out successfully using high temperature melting facility at KAERI. The volume reduction factor of 1/7 and the economical feasibility of the melting decontamination were verified.

  17. Self-aligned nanocrystalline ZnO hexagons by facile solid-state and co-precipitation route

    International Nuclear Information System (INIS)

    Thorat, J. H.; Kanade, K. G.; Nikam, L. K.; Chaudhari, P. D.; Panmand, R. P.; Kale, B. B.

    2012-01-01

    In this study, we report the synthesis of well-aligned nanocrystalline hexagonal zinc oxide (ZnO) nanoparticles by facile solid-state and co-precipitation method. The co-precipitation reactions were performed using aqueous and ethylene glycol (EG) medium using zinc acetate and adipic acid to obtain zinc adipate and further decomposition at 450 °C to confer nanocrystalline ZnO hexagons. XRD shows the hexagonal wurtzite structure of the ZnO. Thermal study reveals complete formation of ZnO at 430 °C in case of solid-state method, whereas in case of co-precipitation method complete formation was observed at 400 °C. Field emission scanning electron microscope shows spherical morphology for ZnO synthesized by solid-state method. The aqueous-mediated ZnO by co-precipitation method shows rod-like morphology. These rods are formed via self assembling of spherical nanoparticles, however, uniformly dispersed spherical crystallites were seen in EG-mediated ZnO. Transmission electron microscope (TEM) investigations clearly show well aligned and highly crystalline transparent and thin hexagonal ZnO. The particle size was measured using TEM and was observed to be 50–60 nm in case of solid-state method and aqueous-mediated co-precipitation method, while 25–50 nm in case of EG-mediated co-precipitation method. UV absorption spectra showed sharp absorption peaks with a blue shift for EG-mediated ZnO, which demonstrate the mono-dispersed lower particle size. The band gap of the ZnO was observed to be 3.4 eV which is higher than the bulk, implies nanocrystalline nature of the ZnO. The photoluminescence studies clearly indicate the strong violet and weak blue emission in ZnO nanoparticles which is quite unique. The process investigated may be useful to synthesize other oxide semiconductors and transition metal oxides.

  18. Self-aligned nanocrystalline ZnO hexagons by facile solid-state and co-precipitation route

    Energy Technology Data Exchange (ETDEWEB)

    Thorat, J. H. [Mahatma Phule College, Department of Chemistry (India); Kanade, K. G. [Annasaheb Awate College (India); Nikam, L. K. [B.G. College (India); Chaudhari, P. D.; Panmand, R. P.; Kale, B. B., E-mail: kbbb1@yahoo.com [Center for Materials for Electronics Technology (C-MET) (India)

    2012-02-15

    In this study, we report the synthesis of well-aligned nanocrystalline hexagonal zinc oxide (ZnO) nanoparticles by facile solid-state and co-precipitation method. The co-precipitation reactions were performed using aqueous and ethylene glycol (EG) medium using zinc acetate and adipic acid to obtain zinc adipate and further decomposition at 450 Degree-Sign C to confer nanocrystalline ZnO hexagons. XRD shows the hexagonal wurtzite structure of the ZnO. Thermal study reveals complete formation of ZnO at 430 Degree-Sign C in case of solid-state method, whereas in case of co-precipitation method complete formation was observed at 400 Degree-Sign C. Field emission scanning electron microscope shows spherical morphology for ZnO synthesized by solid-state method. The aqueous-mediated ZnO by co-precipitation method shows rod-like morphology. These rods are formed via self assembling of spherical nanoparticles, however, uniformly dispersed spherical crystallites were seen in EG-mediated ZnO. Transmission electron microscope (TEM) investigations clearly show well aligned and highly crystalline transparent and thin hexagonal ZnO. The particle size was measured using TEM and was observed to be 50-60 nm in case of solid-state method and aqueous-mediated co-precipitation method, while 25-50 nm in case of EG-mediated co-precipitation method. UV absorption spectra showed sharp absorption peaks with a blue shift for EG-mediated ZnO, which demonstrate the mono-dispersed lower particle size. The band gap of the ZnO was observed to be 3.4 eV which is higher than the bulk, implies nanocrystalline nature of the ZnO. The photoluminescence studies clearly indicate the strong violet and weak blue emission in ZnO nanoparticles which is quite unique. The process investigated may be useful to synthesize other oxide semiconductors and transition metal oxides.

  19. Ion Exchange Equilibrium and Kinetic Properties of Polyacrylate Films and Applications to Chemical Analysis and Environmental Decontamination

    Science.gov (United States)

    Tanner, Stephen P.

    1997-01-01

    One of the goals of the original proposal was to study how cross-linking affects the properties of an ion exchange material(IEM) developed at Lewis Research Center. However, prior to the start of this work, other workers at LERC investigated the effect of cross-linking on the properties of this material. Other than variation in the ion exchange capacity, the chemical characteristics were shown to be independent of the cross-linking agent, and the degree of cross-linking. New physical forms of the film were developed (film, supported film, various sizes of beads, and powder). All showed similar properties with respect to ion exchange equilibria but the kinetics of ion exchange depended on the surface area per unit mass; the powder form of the IEM exchanging much more rapidly than the other forms. The research performed under this grant was directed towards the application of the IEM to the analysis of metal ions at environmental concentrations.

  20. Tritium decontamination of machine components and walls

    International Nuclear Information System (INIS)

    Hircq, B.; Wong, K.Y.; Jalbert, R.A.; Shmayda, W.T.

    1991-01-01

    Tritium decontamination techniques for machine components and their application at tritium handling facilities are reviewed. These include commonly used methods such as vacuuming, purging, thermal desorption and isotopic exchange as well as less common methods such as chemical/electrochemical etching, plasma discharge cleaning, and destructive methods. Problems associated with tritium contamination of walls and use of protective coatings are reviewed. Tritium decontamination considerations at fusion facilities are discussed

  1. Sequestration of uranium on fabricated aluminum co-precipitated with goethite (Al-FeOOH)

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yubing; Yang, Shubin; Wang, Qi; Wang, Xiangke [Chinese Academy of Science, Hefei (China). Key Laboratory of Novel Thin Film Solar Cells; Alsaedi, Ahmad [King Abdulaziz Univ., Jeddah (Saudi Arabia). Nonlinear Analysis and Applied Mathematics (NAAM) Research Group

    2014-11-01

    Aluminum co-precipitated with goethites (Al-FeOOHs) are ubiquitous within (sub)-surface environments, which are considered one of the most important sinks for radionuclide pollution management. Accordingly, various mole ratios Al-FeOOH were synthesized and characterized by XRD, FT-IR, TEM, specific surface area and potentiometric acid-base titration. According to XRD and TEM images, the morphology of Al-FeOOH was transformed from acicular-like goethite to cotton-like gibbsite with increasing Al content. The adsorption and sequential desorption of U(VI) on Al-FeOOHs were conducted by batch techniques under N{sub 2} conditions. The batch adsorption results showed that the adsorption of U(VI) on Al-FeOOHs slightly increased at pH < 4.0, then the significant increase of U(VI) adsorption was observed at pH from 4.0 to 7.0, whereas the suppressed adsorption at pH > 8.0 was due to the electrostatic repulsion between negative charge surface and negative carbonato-complexes. The adsorption of U(VI) on Al-FeOOHs was independent of ionic strength at pH > 5.0, indicating that the inner-sphere surface complexation predominated their adsorption behaviors, whereas U(VI) adsorption on Al-FeOOH could be the outer-sphere surface/cation exchange reaction. The sequential extraction texts showed that the desorption of U(VI) from Al-FeOOHs decreased with increasing Al content. These findings highlighted the effect of Al content on the sequestration and immobilization of U(VI) onto Al-FeOOHs from (sub)-surface environments in pollution management.

  2. Parametric study on co-precipitation of U/Th in MOX fuel of AHWR

    International Nuclear Information System (INIS)

    Tiwari, S.K.; Swaroopa Lakshmi, Y.; Nath, Baidurjya; Setty, D.S.; Kalyana Krishnan, G.; Saibaba, N.

    2015-01-01

    During manufacturing of Mixed Oxide Fuel (MOX) pellets for Advance Heavy Water Reactor (AHWR-LEU), around 30% rejected MOX pellets are generated in every cycle. These rejected MOX pellets are dissolved in nitric acid for recovery of U/Th. The recovered U/Th is recycled for production of MOX pellets. MOX pellets of varying compositions are used in AHWR fuel. Dissolution of MOX pellets in nitric acid is a challenging task because of its low surface area and longer dissolution times. High normal nitric acid is used in order to increase rate of dissolution, which in turn results in generation of high free acidity solution which influences the precipitation characteristics of Uranium (VI) by oxalic acid. Oxalic acid precipitation helps in generation of nitric acid which can be used for dissolution there by effectively facilitating nil effluent generation. Precipitation by oxalic acid unlike ammonia has advantage of zero liquid effluent discharge by complete recycle of oxalate filtrate to dissolution section. In the present work, the effect of various parameters like free acidity, residence time, concentration of oxalic acid, initial concentration of uranium and thorium etc. on the precipitation of U(VI) and Th(IV) in nitrate media by oxalic acid was carried out. The precipitated powder was subjected to various morphological evaluations like particle size etc. Study of various parameters on the co-precipitation of uranium and thorium by oxalic acid was carried out. It was observed that complete precipitation (> 99.9%) of thorium as oxalate does not depend on free acidity range (1- 6 N). Excess oxalic acid is not required for complete precipitation of thorium oxalate. The precipitation of uranyl oxalate varies with initial free acidity of solution. Uranyl oxalate precipitation does not take place at and above 5 N of free acidity

  3. Ontario Hydro decontamination experience

    Energy Technology Data Exchange (ETDEWEB)

    Lacy, C S; Patterson, R W; Upton, M S [Chemistry and Metallurgy Department, Central Production Services, Ontario Hydro, ON (Canada)

    1991-04-01

    Ontario Hydro currently operates 18 nuclear electric generating units of the CANDU design with a net capacity of 12,402 MW(e). An additional 1,762 MW(e) is under construction. The operation of these facilities has underlined the need to have decontamination capability both to reduce radiation fields, as well as to control and reduce contamination during component maintenance. This paper presents Ontario Hydro decontamination experience in two key areas - full heat transport decontamination to reduce system radiation fields, and component decontamination to reduce loose contamination particularly as practised in maintenance and decontamination centres. (author)

  4. Ontario Hydro decontamination experience

    International Nuclear Information System (INIS)

    Lacy, C.S.; Patterson, R.W.; Upton, M.S.

    1991-01-01

    Ontario Hydro currently operates 18 nuclear electric generating units of the CANDU design with a net capacity of 12,402 MW(e). An additional 1,762 MW(e) is under construction. The operation of these facilities has underlined the need to have decontamination capability both to reduce radiation fields, as well as to control and reduce contamination during component maintenance. This paper presents Ontario Hydro decontamination experience in two key areas - full heat transport decontamination to reduce system radiation fields, and component decontamination to reduce loose contamination particularly as practised in maintenance and decontamination centres. (author)

  5. Efficacy of scalp hair decontamination following exposure to vapours of sulphur mustard simulants 2-chloroethyl ethyl sulphide and methyl salicylate

    OpenAIRE

    Spiandore , Marie; Piram , Anne; Lacoste , Alexandre; Prevost , P.; Maloni , Pascal; TORRE , Franck; Asia , L.; Josse , D.; Doumenq , Pierre

    2017-01-01

    International audience; Chemical warfare agents are an actual threat and victims' decontamination is a main concern when mass exposure occurs. Skin decontamination with current protocols has been widely documented, as well as surface decontamination. However, considering hair ability to trap chemicals in vapour phase, we investigated hair decontamination after exposure to sulphur mustard simulants methyl salicylate and 2-chloroethyl ethyl sulphide. Four decontamination protocols were tested o...

  6. Field pilot testing for chemical oxidation at the former Nitchequon meteorological station : decontamination project in isolated areas

    Energy Technology Data Exchange (ETDEWEB)

    Peisajovich, A. [Transport Canada, Montreal, PQ (Canada); Bergeron, E. [Golder Associates Ltd., Montreal, PQ (Canada); Barbeau, M. [Golder Associates Innovative Applications, Montreal, PQ (Canada); Lajoie, G. [Cree Regional Authority, Montreal, PQ (Canada)

    2006-07-01

    Field pilot testing for chemical oxidation at the former Nitchequon meteorological station was discussed. This presentation described the site location and provided an aerial view and cross section of the site. The historical background and condition of the site were then identified. Photographs and illustrations of the site and the source of the problem were provided. Photographs were also provided of the logistics, temporary camp, dismantling of tanks, equipment, pipeline dismantling, residues, methodology as well as a graphical representation of how to solve the problem. Other topics included technologies tested on site, full-scale remediation plans, remediation goals, step by step process, and costs distribution. Among the steps discussed was: vegetation removal; excavation of the first two feet of soil; transfer of contaminated soil on high-density polyethylene (HDPE) lining prior to treatment; cell construction; cell lining insulation; transfer of treated soil from the mixers to the curing cells; installation of HDPE top cover lining over the treated soil; and the addition of 12 inches of clean soil over the top cover lining. tabs., figs.

  7. Oxidative Tritium Decontamination System

    International Nuclear Information System (INIS)

    Gentile, Charles A.; Parker, John J.; Guttadora, Gregory L.; Ciebiera, Lloyd P.

    2002-01-01

    The Princeton Plasma Physics Laboratory, Tritium Systems Group has developed and fabricated an Oxidative Tritium Decontamination System (OTDS), which is designed to reduce tritium surface contamination on various components and items. The system is configured to introduce gaseous ozone into a reaction chamber containing tritiated items that require a reduction in tritium surface contamination. Tritium surface contamination (on components and items in the reaction chamber) is removed by chemically reacting elemental tritium to tritium oxide via oxidation, while purging the reaction chamber effluent to a gas holding tank or negative pressure HVAC system. Implementing specific concentrations of ozone along with catalytic parameters, the system is able to significantly reduce surface tritium contamination on an assortment of expendable and non-expendable items. This paper will present the results of various experimentation involving employment of this system

  8. Decontamination of organic waste

    International Nuclear Information System (INIS)

    Schulz, W.

    1977-01-01

    Decontamination stands for the sack collecting of wc-waste water of nuclear-medical tracts and especially the collecting of primary urine and primary faeces of patients after application of radio-isotopes (e.g. iodine 131). They are tied up in the sacks, treated with antiseptic and decomposition-preventing agents, and finally stored in a decupation depot over the time constant. The decupation depot can, for example, be a deep-freezor with separations and clocks, which is radiation-isolated. After the time constant a chemical and/or physical destruction (e.g. comminution) takes place, with simultaneous disinfection and thawing (vapour heating) and the transfer to the canalization. (DG) [de

  9. Effectiveness of Vaporous Hydrogen Peroxide for the Decontamination of Representative Military Materials

    National Research Council Canada - National Science Library

    Dutt, D. L; Turetsky, A. L; Brickhouse, M; Pfarr, J. W; McVey, I. F; Meilander, S. L; Janick, A. J; Schulte, S. L; Dallmier, A. W

    2004-01-01

    .... While many chemical decontamination methods, including aqueous hydrogen peroxide, have been used or are under development for direct application, few vaporous methods are being evaluated for decontamination efficacy (McDonnell, G. et al., 2002...

  10. Skin contamination - prevention and decontaminating

    International Nuclear Information System (INIS)

    Henning, K.

    2001-01-01

    A detailed examination is made of the structure of human skin. Measures were drawn up to prevent skin contamination in nuclear installations as well as contaminated skin was decontaminated from the personnel. By systematically applying these measures a significant level of success was achieved in preventing contamination in nuclear installations. Cases where more far-reaching chemical methods had to be used were kept to a minimum. (R.P.)

  11. Revisiting Pocos de Caldas. Application of the co-precipitation approach to establish realistic solubility limits for performance assessment

    International Nuclear Information System (INIS)

    Bruno, J.; Duro, L.; Jordana, S.; Cera, E.

    1996-02-01

    Solubility limits constitute a critical parameter for the determination of the mobility of radionuclides in the near field and the geosphere, and consequently for the performance assessment of nuclear waste repositories. Mounting evidence from natural system studies indicate that trace elements, and consequently radionuclides, are associated to the dynamic cycling of major geochemical components. We have recently developed a thermodynamic approach to take into consideration the co-precipitation and co-dissolution processes that mainly control this linkage. The approach has been tested in various natural system studies with encouraging results. The Pocos de Caldas natural analogue was one of the sites where a full testing of our predictive geochemical modelling capabilities were done during the analogue project. We have revisited the Pocos de Caldas data and expanded the trace element solubility calculations by considering the documented trace metal/major ion interactions. This has been done by using the co-precipitation/co-dissolution approach. The outcome is as follows: A satisfactory modelling of the behaviour of U, Zn and REEs is achieved by assuming co-precipitation with ferrihydrite. Strontium concentrations are apparently controlled by its co-dissolution from Sr-rich fluorites. From the performance assessment point of view, the present work indicates that calculated solubility limits using the co-precipitation approach are in close agreement with the actual trace element concentrations. Furthermore, the calculated radionuclide concentrations are 2-4 orders of magnitude lower than conservative solubility limits calculated by assuming equilibrium with individual trace element phases. 34 refs, 18 figs, 13 tabs

  12. Revisiting Pocos de Caldas. Application of the co-precipitation approach to establish realistic solubility limits for performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, J.; Duro, L.; Jordana, S.; Cera, E. [QuantiSci, Barcelona (Spain)

    1996-02-01

    Solubility limits constitute a critical parameter for the determination of the mobility of radionuclides in the near field and the geosphere, and consequently for the performance assessment of nuclear waste repositories. Mounting evidence from natural system studies indicate that trace elements, and consequently radionuclides, are associated to the dynamic cycling of major geochemical components. We have recently developed a thermodynamic approach to take into consideration the co-precipitation and co-dissolution processes that mainly control this linkage. The approach has been tested in various natural system studies with encouraging results. The Pocos de Caldas natural analogue was one of the sites where a full testing of our predictive geochemical modelling capabilities were done during the analogue project. We have revisited the Pocos de Caldas data and expanded the trace element solubility calculations by considering the documented trace metal/major ion interactions. This has been done by using the co-precipitation/co-dissolution approach. The outcome is as follows: A satisfactory modelling of the behaviour of U, Zn and REEs is achieved by assuming co-precipitation with ferrihydrite. Strontium concentrations are apparently controlled by its co-dissolution from Sr-rich fluorites. From the performance assessment point of view, the present work indicates that calculated solubility limits using the co-precipitation approach are in close agreement with the actual trace element concentrations. Furthermore, the calculated radionuclide concentrations are 2-4 orders of magnitude lower than conservative solubility limits calculated by assuming equilibrium with individual trace element phases. 34 refs, 18 figs, 13 tabs.

  13. Mercury (II) reduction and co-precipitation of metallic mercury on hydrous ferric oxide in contaminated groundwater.

    Science.gov (United States)

    Richard, Jan-Helge; Bischoff, Cornelia; Ahrens, Christian G M; Biester, Harald

    2016-01-01

    Mercury (Hg) speciation and sorption analyses in contaminated aquifers are useful for understanding transformation, retention, and mobility of Hg in groundwater. In most aquifers hydrous ferric oxides (HFOs) are among the most important sorbents for trace metals; however, their role in sorption or mobilization of Hg in aquifers has been rarely analyzed. In this study, we investigated Hg chemistry and Hg sorption to HFO under changing redox conditions in a highly HgCl2-contaminated aquifer (up to 870μgL(-1) Hg). Results from aqueous and solid phase Hg measurements were compared to modeled (PHREEQC) data. Speciation analyses of dissolved mercury indicated that Hg(II) forms were reduced to Hg(0) under anoxic conditions, and adsorbed to or co-precipitated with HFO. Solid phase Hg thermo-desorption measurements revealed that between 55 and 93% of Hg bound to HFO was elemental Hg (Hg(0)). Hg concentrations in precipitates reached more than 4 weight %, up to 7000 times higher than predicted by geochemical models that do not consider unspecific sorption to and co-precipitation of elemental Hg with HFO. The observed process of Hg(II) reduction and Hg(0) formation, and its retention and co-precipitation by HFO is thought to be crucial in HgCl2-contaminated aquifers with variable redox-conditions regarding the related decrease in Hg solubility (factor of ~10(6)), and retention of Hg in the aquifer. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Evaluation of Three Chitin Metal Silicate Co-Precipitates as a Potential Multifunctional Single Excipient in Tablet Formulations

    Directory of Open Access Journals (Sweden)

    Rana Al-Shaikh Hamid

    2010-05-01

    Full Text Available The performance of the novel chitin metal silicate (CMS co-precipitates as a single multifunctional excipient in tablet formulation using direct compression and wet granulation methods is evaluated. The neutral, acidic, and basic drugs Spironolactone (SPL, ibuprofen (IBU and metronidazole (MET, respectively, were used as model drugs. Commercial Aldactone®, Fleximex® and Dumazole® tablets containing SPL, IBU and MET, respectively, and tablets made using Avicel® 200, were used in the study for comparison purposes. Tablets of acceptable crushing strength (>40 N were obtained using CMS. The friability values for all tablets were well below the maximum 1% USP tolerance limit. CMS produced superdisintegrating tablets (disintegration time < 1 min with the three model drugs. Regarding the dissolution rate, the sequence was as follow: CMS > Fleximex® > Avicel® 200, CMS > Avicel® 200 > Dumazole® and Aldactone® > Avicel® 200 > CMS for IBU, MET and SPL, respectively. Compressional properties of formulations were analyzed using density measurements and the compression Kawakita equation as assessment parameters. On the basis of DSC results, CMS co precipitates were found to be compatible with the tested drugs. Conclusively, the CMS co-precipitates have the potential to be used as filler, binder, and superdisintegrant, all-in-one, in the design of tablets by the direct compression as well as wet granulation methods.

  15. Enhanced toxic cloud knockdown spray system for decontamination applications

    Science.gov (United States)

    Betty, Rita G [Rio Rancho, NM; Tucker, Mark D [Albuquerque, NM; Brockmann, John E [Albuquerque, NM; Lucero, Daniel A [Albuquerque, NM; Levin, Bruce L [Tijeras, NM; Leonard, Jonathan [Albuquerque, NM

    2011-09-06

    Methods and systems for knockdown and neutralization of toxic clouds of aerosolized chemical or biological warfare (CBW) agents and toxic industrial chemicals using a non-toxic, non-corrosive aqueous decontamination formulation.

  16. Decontamination Efficacy and Skin Toxicity of Two Decontaminants against Bacillus anthracis.

    Directory of Open Access Journals (Sweden)

    Chad W Stratilo

    Full Text Available Decontamination of bacterial endospores such as Bacillus anthracis has traditionally required the use of harsh or caustic chemicals. The aim of this study was to evaluate the efficacy of a chlorine dioxide decontaminant in killing Bacillus anthracis spores in solution and on a human skin simulant (porcine cadaver skin, compared to that of commonly used sodium hypochlorite or soapy water decontamination procedures. In addition, the relative toxicities of these decontaminants were compared in human skin keratinocyte primary cultures. The chlorine dioxide decontaminant was similarly effective to sodium hypochlorite in reducing spore numbers of Bacillus anthracis Ames in liquid suspension after a 10 minute exposure. After five minutes, the chlorine dioxide product was significantly more efficacious. Decontamination of isolated swine skin contaminated with Bacillus anthracis Sterne with the chlorine dioxide product resulted in no viable spores sampled. The toxicity of the chlorine dioxide decontaminant was up to two orders of magnitude less than that of sodium hypochlorite in human skin keratinocyte cultures. In summary, the chlorine dioxide based decontaminant efficiently killed Bacillus anthracis spores in liquid suspension, as well as on isolated swine skin, and was less toxic than sodium hypochlorite in cultures of human skin keratinocytes.

  17. Development of acidic processes for decontaminating LMFBR components

    Energy Technology Data Exchange (ETDEWEB)

    Hill, E F [Rockwell International, Atomics International Division, Canoga Park (United States); Colburn, R P; Lutton, J M; Maffei, H P [Hanford Engineering Development Laboratory, Richland (United States)

    1978-08-01

    The objective of the DOE decontamination program is to develop a well characterized chemical decontamination process for application to LMFBR primary system components that subsequently permits contact maintenance and allows requalification of the components for reuse in reactors. The paper describes the subtasks of deposit characterization, development of requalification and process acceptance criteria, development of process evaluation techniques and studies which led to a new acidic process for decontaminating 304 stainless steel hot leg components.

  18. Decontamination and dismantlement of Plant 7 at Fernald

    International Nuclear Information System (INIS)

    Albertin, M.; Borgman, T.; Zebick, B.

    1994-01-01

    Decontamination and dismantlement (D ampersand D) tasks have been successfully completed on Plant 7 at the Fernald Environmental Management Project. The seven story facility was radiologically, chemically, and biologically contaminated. The work involved the D ampersand D work beginning with safe shutdown and gross decontamination, and ended with removal of the structural steel. A series of lessons learned were gained which include use of explosives, bidding tactics, safe shutdown, building decontamination and lockdown, use of seam climbers, etc

  19. Development of acidic processes for decontaminating LMFBR components

    International Nuclear Information System (INIS)

    Hill, E.F.; Colburn, R.P.; Lutton, J.M.; Maffei, H.P.

    1978-01-01

    The objective of the DOE decontamination program is to develop a well characterized chemical decontamination process for application to LMFBR primary system components that subsequently permits contact maintenance and allows requalification of the components for reuse in reactors. The paper describes the subtasks of deposit characterization, development of requalification and process acceptance criteria, development of process evaluation techniques and studies which led to a new acidic process for decontaminating 304 stainless steel hot leg components

  20. Development of a calcium phosphate co-precipitate/poly(lactide-co-glycolide) DNA delivery system: release kinetics and cellular transfection studies.

    Science.gov (United States)

    Kofron, Michelle D; Laurencin, Cato T

    2004-06-01

    One of the most common non-viral methods for the introduction of foreign deoxyribonucleic acid (DNA) into cultured cells is calcium phosphate co-precipitate transfection. This technique involves the encapsulation of DNA within a calcium phosphate co-precipitate, particulate addition to in vitro cell culture, endocytosis of the co-precipitate, and exogenous DNA expression by the transfected cell. In this study, we fabricated a novel non-viral gene transfer system by adsorbing DNA, encapsulated in calcium phosphate (DNA/Ca-P) co-precipitates, to biodegradable two- and three-dimensional poly(lactide-co-glycolide) matrices (2D-DNA/Ca-P/PLAGA, 3D-DNA/Ca-P/PLAGA). Co-precipitate release studies demonstrated an initial burst release over the first 48 h. By day 7, approximately 96% of the initially adsorbed DNA/Ca-P co-precipitate had been released. This was followed by low levels of co-precipitate release for 42 days. Polymerase chain reaction was used to demonstrate the ability of the released DNA containing co-precipitates to transfect SaOS-2 cells cultured in vitro on the 3D-DNA/Ca-P/PLAGA matrix and maintenance of the structural integrity of the exogenous DNA. In summary, a promising system for the incorporation and controlled delivery of exogenous genes encapsulated within a calcium phosphate co-precipitate from biodegradable polymeric matrices has been developed and may have applicability to the delivery of therapeutic genes and the transfection of other cell types.

  1. Urban Decontamination Experience at Pripyat Ukraine - 13526

    Energy Technology Data Exchange (ETDEWEB)

    Paskevych, Sergiy [Institute for Safety Problems of Nuclear Power Plants, National Academy of Sciences of Ukraine, 36 a Kirova str. Chornobyl, Kiev region, 07200 (Ukraine); Voropay, Dmitry [Federal State Unitary Enterprise ' Russian State Center of Inventory and Registration and Real Estate - Federal Bureau of Technical Inventory' , 37-2 Bernadsky Prospekt, Moscow Russia 119415 (Russian Federation); Schmieman, Eric [Battelle Memorial Institute, PO Box 999 MSIN K6-90, Richland, WA 99352 (United States)

    2013-07-01

    This paper describes the efficiency of radioactive decontamination activities of the urban landscape in the town of Pripyat, Ukraine. Different methods of treatment for various urban infrastructure and different radioactive contaminants are assessed. Long term changes in the radiation condition of decontaminated urban landscapes are evaluated: 1. Decontamination of the urban system requires the simultaneous application of multiple methods including mechanical, chemical, and biological. 2. If a large area has been contaminated, decontamination of local areas of a temporary nature. Over time, there is a repeated contamination of these sites due to wind transport from neighboring areas. 3. Involvement of earth-moving equipment and removal of top soil by industrial method achieves 20-fold reduction in the level of contamination by radioactive substances, but it leads to large amounts of waste (up to 1500 tons per hectare), and leads to the re-contamination of treated areas due to scatter when loading, transport pollutants on the wheels of vehicles, etc.. (authors)

  2. Decontamination of body surface

    International Nuclear Information System (INIS)

    Harase, Chieko.

    1989-01-01

    There are two important points for an effective application of decontamination procedures. One is the organizing method of responsible decontamination teams. The team should be directed by medical doctor with the knowledge of decontamination of radionuclides. The other point is the place of application of the decontamination. Hospitals and clinics, especially with a department of nuclear medicine, or specialized units such as an emergency medical center are preferable. Before decontamination procedures are initiated, adequate monitoring of the body surface should be undertaken by a competent person in order to demarcate the areas which are contaminated. There are fundamental principles which are applicable to all decontamination procedures. (1) Precautions must always be taken to prevent further spread of contamination during decontamination operations. (2) Mild decontamination methods should be tried before resorting to treatment which can damage the body surface. The specific feature of each contamination varies widely in radionuclides involved, place and area of the contamination, condition of the contaminated skin such as whether the skin is wounded or not, and others. Soap and water are usually good detergents in most cases. If they fail, orange oil cream (SUPERDECONCREAM, available from Tokyo Engineering Co.) specially prepared for decontamination of radionuclides of most fission and corrosion products may be used. Contaminated hair should be washed several times with an efficient shampoo. (author)

  3. Development of strippable gel for surface decontamination applications

    International Nuclear Information System (INIS)

    Banerjee, D.; Sandhya, U.; Khot, S.A.; Srinivas, C.

    2015-07-01

    Strippable gels are an attractive option for decontamination of surfaces particularly when materials are to be reused after decontamination. The process in general results in good decontamination performance with minimal secondary waste generation. This paper reports on development of strippable gel formulation using polyvinyl alcohol as the gel former. Peeling behavior of the gel film improved when glycerol was used as plasticizer. Incorporation of decontaminating agents is essential for the gel to be effective, so a number of decontaminating agents were screened based on their miscibility with the gel, smooth peeling, and good decontamination performance. Based on this study, a strippable gel, ‘INDIGEL’ was formulated as a potential candidate for surface decontamination applications. Extensive trials on evaluation of decontamination performance of Indigel were done on simulated surfaces like stainless steel tray, stainless steel fume hood, PVC floor, granite and ceramic table tops. Results show that Indigel is highly effective for decontamination of surfaces contaminated with all types of radionuclides. Simplicity of its use coupled with good decontamination ability will find application in nuclear and other chemical industries. (author)

  4. Intervention and decontamination of hardware contaminated by tritium

    International Nuclear Information System (INIS)

    Cerre, Pierre; Mestre, Emile

    1964-10-01

    This report first describes the intervention process for teams intervening, either in case of accident or to modify or repair installations in which tritium is handled, i.e. in both cases in a contaminated atmosphere. Three main aspects are addressed: how to prepare and insulate the work place from the rest of the installation, how to protect the intervening personnel, and how to perform decontamination. The authors then present the various available decontamination techniques: decontamination bath at different temperatures and use of different chemical solutions at different temperatures, the degassing technique (temperature increase and vacuum, temperature hold during 30 to 45 minutes, return to atmospheric pressure), and mercury-based decontamination

  5. Decontamination and materials corrosion concerns in the BWR

    International Nuclear Information System (INIS)

    Gordon, B.M.; Gordon, G.M.

    1988-01-01

    The qualification of chemical decontamination processes to decontaminate complete systems or individual components in essential if effective inspection, maintenance, repair or replacement of plant components is to be achieved with minimum exposure of workers to ionizing radiation. However, it is critical that the benefits of decontamination processes are not overshadowed by deleterious materials/ corrosion side effects during the application of the process or during subsequent operation. This paper discusses such potential corrosion/materials problems in the BWR and presents relevant available corrosion data for the various commercial decontamination processes. (author)

  6. Impact of decontamination on LWR radioactive waste treatment systems

    International Nuclear Information System (INIS)

    Hoenes, G.R.; Perrigo, L.D.; Divine, J.R.; Faust, L.G.

    1979-01-01

    Only at N-Reactor is there a means to accommodate radwaste produced during decontamination. The Dresden system is expected to be ready to accommodate such solutions by the summer of 1979. Solidification of the processed decontamination waste may be a significant problem. There is doubt that the materials in current radwaste treatment systems can handle chemicals from a concentrated process. The total storage volume, for concentrated decontamination, is not sufficient in existing radwaste treatment systems. Greater attention should be placed on designing reactors and radwaste treatment systems for decontamination. A means of handling waste material resulting from leaks in the primary system during the decontamination must be developed. On-site storage of solidified decontamination wastes may be a viable option, but license amendments will be necessary

  7. New quaternary ammonium salts based decontaminants

    Directory of Open Access Journals (Sweden)

    Diana M. Popescu

    2014-06-01

    Full Text Available Decontamination after terrorist attacks or industrial accidents with biological and/or chemical agents („bio-chem“ must be fast and efficient, in order to reduce the number of victims and to eliminate the consequent damages. The decontamination of living biological agents (bacteria, viruses or nonliving ones (toxins, regulators and toxic chemicals could be accomplished by reactions of hydrolysis in various experimental conditions, in particular in alkaline medium, reactions with amines or ammonia, alcohols, phenols etc. and by their transformation into less toxic degradation products. “Bio-chem” intentional or unintentional contamination is a real risk, towards which an effective management must be available to prevent and control it. Decontamination is an essential measure to protect the personnel and the environment. Synthesis and testing of new „bio-chem“ decontaminants, based on quaternary ammonium salts, complete the arsenal of protection against chemical and biological agents. The most effective selected substances could be produced and used for decontamination in accordance with legal procedures

  8. Synthesis of InGaZnO{sub 4} nanoparticles using low temperature multistep co-precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Ming-Chung, E-mail: mingchungwu@mail.cgu.edu.tw; Hsiao, Kai-Chi; Lu, Hsin-Chun

    2015-07-15

    Indium gallium zinc oxide (InGaZnO{sub 4}, IGZO) has attracted explosive growth in investigations over the last decades as an important material in the thin-film transistor. In this study, the various nitrate precursors, including indium nitrate, gallium nitrate, and zinc nitrate, were prepared from the various metals dissolved in nitric acid. Then, we used these nitrate precursors to synthesize the IGZO precursor powder by the multistep co-precipitation method. The synthesis parameters of the co-precipitation method, such as reaction temperature, pH value and reaction time, were controlled precisely to prepare the high quality IGZO precursor powder. Finally, IGZO precursor powder was calcined at 900 °C. Then, the microstructure, the crystalline structure, the particle size distribution and specific surface area of calcined IGZO precursor powder were characterized by electron transmission microscopy, X-ray diffraction technique, dynamic light scattering method and the surface area and porosimetry analyzer, respectively. The relative density of IGZO tablet sintered at 1200 °C for 12 h is as high as 97.30%, and it showed highly InGaZnO{sub 4} crystalline structure and the large grain size. The IGZO nanoparticles developed in our study has the potential for the high quality target materials used in the application of electronic devices. - Graphical abstract: Display Omitted - Highlights: • InGaZnO{sub 4} (IGZO) nanoparticle was synthesized by multistep co-precipitation method. • The synthesis parameters were controlled precisely to prepare high quality powder. • The relative density of highly crystalline IGZO tablet is as high as 97.30%. • IGZO tablet exhibited highly crystalline structure and the large grain size.

  9. Synthesis of InGaZnO4 nanoparticles using low temperature multistep co-precipitation method

    International Nuclear Information System (INIS)

    Wu, Ming-Chung; Hsiao, Kai-Chi; Lu, Hsin-Chun

    2015-01-01

    Indium gallium zinc oxide (InGaZnO 4 , IGZO) has attracted explosive growth in investigations over the last decades as an important material in the thin-film transistor. In this study, the various nitrate precursors, including indium nitrate, gallium nitrate, and zinc nitrate, were prepared from the various metals dissolved in nitric acid. Then, we used these nitrate precursors to synthesize the IGZO precursor powder by the multistep co-precipitation method. The synthesis parameters of the co-precipitation method, such as reaction temperature, pH value and reaction time, were controlled precisely to prepare the high quality IGZO precursor powder. Finally, IGZO precursor powder was calcined at 900 °C. Then, the microstructure, the crystalline structure, the particle size distribution and specific surface area of calcined IGZO precursor powder were characterized by electron transmission microscopy, X-ray diffraction technique, dynamic light scattering method and the surface area and porosimetry analyzer, respectively. The relative density of IGZO tablet sintered at 1200 °C for 12 h is as high as 97.30%, and it showed highly InGaZnO 4 crystalline structure and the large grain size. The IGZO nanoparticles developed in our study has the potential for the high quality target materials used in the application of electronic devices. - Graphical abstract: Display Omitted - Highlights: • InGaZnO 4 (IGZO) nanoparticle was synthesized by multistep co-precipitation method. • The synthesis parameters were controlled precisely to prepare high quality powder. • The relative density of highly crystalline IGZO tablet is as high as 97.30%. • IGZO tablet exhibited highly crystalline structure and the large grain size

  10. Fe-based soft magnetic composites coated with NiZn ferrite prepared by a co-precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Yuandong; Yi, Yi; Li, Liya; Ai, Hengyu; Wang, Xiaoxu [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Chen, Lulu [Jiangsu Eagle-globe Group Co., Ltd., Nantong 226600 (China)

    2017-04-15

    Fe powder was coated with NiZn ferrite by a co-precipitation method using chlorate as the raw material. Soft magnetic composites were manufactured via compaction and heat treatment of the coated powder. The coated powder and heat treated powder were analysed using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and Raman spectroscopy. Their magnetic properties were determined using a Quantum Design-Vibrating Sample Magnetometer (QD-VSM). The composites were analysed with SEM and EDS. The permeability and magnetic loss of the composites were measured with a B-H curve analyzer. The results show that, using the co-precipitation method, the raw precipitate was successfully prepared and coated the pure Fe powder and turned into spinel NiZn ferrite treated at 600 ℃ for 1 h. After heat treatment at 500 ℃ under air, the insulation coating layer of soft magnetic composite (SMC) was not destroyed and containing Fe, Ni, Zn and oxygen. The permeabilities of the SMC are stable at edge of the 2–200 kHz frequency range and the total loss was lower. - Graphical abstract: Scanning electron microscopy (SEM) images of Fe/(NiZn)Fe{sub 2}O{sub 4} composite powder heated at 600 ℃ for 1 h. - Highlights: • Fe particles were coated with (NiZn)Fe{sub 2}O{sub 4} via a co-precipitation and calcined method. • Coating layers were uniform and dense. • The permeabilities of the SMC are stable at edge of the 2–200 kHz frequency range.

  11. Decontamination of floor surfaces

    International Nuclear Information System (INIS)

    Smirous, F.

    1983-01-01

    Requirements are presented put on the surfaces of floors of radiochemical workplaces. The mechanism is described of retaining the contaminant in the surface of the flooring, ways of reducing the hazards of floor surface contamination, decontamination techniques and used decontamination agents. (J.P.)

  12. Effect of pH on the Structural and Magnetic Properties of Magnetite Nanoparticles Synthesised by Co-Precipitation

    International Nuclear Information System (INIS)

    Ramadan, W.; Kareem, M.; Hannoyer, B.; Saha, Sh.

    2011-01-01

    Magnetite, Fe3O4, nanoparticles were synthesized using co-precipitation aqueous method at room temperature and at different pH, from 8 to 12.5. The pH value was found to influence greatly the resulting phases and has no significant effect on the particle size. In all cases, magnetite was found to be the main phase but the contribution of Goethite phase was identified clearly with the increase in pH. Significant reduction in saturation magnetization was evident. Structural and magnetic properties of the nanoparticles were examined using; XRD, TEM, Raman Spectroscopy and SQUID. (author)

  13. Radioactive contamination of some rubber or plastic surfaces by fission products. Decontamination tests

    International Nuclear Information System (INIS)

    Mestre, E.; Sautiez, N.

    1957-10-01

    With the objective of notably addressing the contamination and decontamination of gloves and floor covering, this report first presents some characteristics of contaminating radioactive materials (nature, physical and chemical condition), of contaminated surfaces (surface condition, surface nature), and of decontamination processes (physical, chemical or mechanical action). It describes the operational modality implemented to test decontamination processes on various glove or flooring materials: sample preparation, counting, decontamination, reproducibility of decontamination tests, results in terms of activity reduction. It more precisely describes the tested samples: short gloves, gloves from glove boxes, floor and wall coverings. Results are presented and discussed in terms of sample susceptibility to contamination, and of decontamination, but also for re-contamination tests after a Nab-based decontamination (susceptibility to contamination, decontamination gain)

  14. Separations canyon decontamination facilities

    International Nuclear Information System (INIS)

    Hershey, J.H.

    1975-01-01

    Highly radioactive process equipment is decontaminated at the Savannah River Plant in specially equipped areas of the separations canyon building so that direct mechanical repairs or alterations can be made. Using these facilities it is possible to decontaminate and repair equipment such as 10- x 11-ft storage tanks, 8- x 8-ft batch evaporator pots and columns, 40-in. Bird centrifuges, canyon pumps and agitators, and various canyon piping systems or ''jumpers.'' For example, centrifuge or evaporator pots can be decontaminated and rebuilt for about 60 percent of the 1974 replacement cost. The combined facilities can decontaminate and repair 6 to 10 pieces of major equipment per year. Decontamination time varies with type of equipment and radioactivity levels encountered

  15. Separations canyon decontamination facilities

    International Nuclear Information System (INIS)

    Hershey, J.H.

    1975-05-01

    Highly radioactive process equipment is decontaminated at the Savannah River Plant in specially equipped areas of the separations canyon buildings so that direct mechanical repairs or alterations can be made. Using these facilities it is possible to decontaminate and repair equipment such as 10- x 11-ft storage tanks, 8- x 8-ft batch evaporator pots and columns, 40-in. Bird centrifuges, canyon pumps and agitators, and various canyon piping systems or ''jumpers.'' For example, centrifuge or evaporator pots can be decontaminated and rebuilt for about 60 percent of the 1974 replacement cost. The combined facilities can decontaminate and repair 6 to 10 pieces of major equipment per year. Decontamination time varies with type of equipment and radioactivity levels encountered. (U.S.)

  16. Cleaning of liquid LLW from decontamination processes using semipermeable membranes

    International Nuclear Information System (INIS)

    Dulama, M.; Deneanu, N.; Pavelescu, M.

    2003-01-01

    Of the three processes, which have been used extensively for liquid radioactive waste purification, evaporation and ion exchange are costly and flocculation gives a low degree of purification. By comparison to that, reverse osmosis offers intermediate purification at reasonable cost. Present research is examining the potential of using a membrane filtration system for the removal of dissolved radionuclides, but chemical treatment showed as necessary to convert soluble radionuclides, organic traces and metals to insoluble, filterable species. Liquid wastes within a CANDU station are segregated into normal and low-activity waste streams. The normal-activity waste includes wastes from the laboratories, laundries, some service-building drains, upgrade drains, and decontamination center. The drains from the reactor building, the heavy-water area, the spent-fuel pool, and the resin storage area are also directed to this normal activity wastes from showers and building drains in areas of the service building that would not normally be contaminated. The aqueous liquid wastes from the decontamination center and the other collected wastes from the chemical drain system are currently treated by the membrane plant. Generally, the liquid waste streams are effectively volume-reduced by a combination of continuous crossflow microfiltration (MF), spiral wound reverse osmosis (SWRO) and tubular reverse osmosis membrane technologies. Backwash chemical cleaning wastes from the membrane plant are further volume-reduced by evaporation. The concentrate from the membrane plant is ultimately immobilized with bitumen. The ability of the MF/SWRO technology to remove impurities non-selectively makes it suitable for the treatment of radioactive effluents from operating nuclear plants, with proper membrane selection, feed characterization, system configuration and system chemistry control. The choice of polysulfonate material for membrane was based on the high flow rates achievable with this

  17. Arsenic Removal from Groundwater by Solar Driven Inline-Electrolytic Induced Co-Precipitation and Filtration—A Long Term Field Test Conducted in West Bengal

    Directory of Open Access Journals (Sweden)

    Philipp Otter

    2017-10-01

    Full Text Available Arsenic contamination in drinking water resources is of major concern in the Ganga delta plains of West Bengal in India and Bangladesh. Here, several laboratory and field studies on arsenic removal from drinking water resources were conducted in the past and the application of strong-oxidant-induced co-precipitation of arsenic on iron hydroxides is still considered as the most promising mechanism. This paper suggests an autonomous, solar driven arsenic removal setting and presents the findings of a long term field test conducted in West Bengal. The system applies an inline-electrolytic cell for in situ chlorine production using the natural chloride content of the water and by that substituting the external dosing of strong oxidants. Co-precipitation of As(V occurs on freshly formed iron hydroxide, which is removed by Manganese Greensand Plus® filtration. The test was conducted for ten months under changing source water conditions considering arsenic (187 ± 45 µg/L, iron (5.5 ± 0.8 mg/L, manganese (1.5 ± 0.4 mg/L, phosphate (2.4 ± 1.3 mg/L and ammonium (1.4 ± 0.5 mg/L concentrations. Depending on the system setting removal rates of 94% for arsenic (10 ± 4 µg/L, >99% for iron (0.03 ± 0.03 mg/L, 96% for manganese (0.06 ± 0.05 mg/L, 72% for phosphate (0.7 ± 0.3 mg/L and 84% for ammonium (0.18 ± 0.12 mg/L were achieved—without the addition of any chemicals/adsorbents. Loading densities of arsenic on iron hydroxides averaged to 31 µgAs/mgFe. As the test was performed under field conditions and the here proposed removal mechanisms work fully autonomously, it poses a technically feasible treatment alternative, especially for rural areas.

  18. Pickering emulsions for skin decontamination.

    Science.gov (United States)

    Salerno, Alicia; Bolzinger, Marie-Alexandrine; Rolland, Pauline; Chevalier, Yves; Josse, Denis; Briançon, Stéphanie

    2016-08-01

    This study aimed at developing innovative systems for skin decontamination. Pickering emulsions, i.e. solid-stabilized emulsions, containing silica (S-PE) or Fuller's earth (FE-PE) were formulated. Their efficiency for skin decontamination was evaluated, in vitro, 45min after an exposure to VX, one of the most highly toxic chemical warfare agents. Pickering emulsions were compared to FE (FE-W) and silica (S-W) aqueous suspensions. PE containing an oil with a similar hydrophobicity to VX should promote its extraction. All the formulations reduced significantly the amount of VX quantified on and into the skin compared to the control. Wiping the skin surface with a pad already allowed removing more than half of VX. FE-W was the less efficient (85% of VX removed). The other formulations (FE-PE, S-PE and S-W) resulted in more than 90% of the quantity of VX removed. The charge of particles was the most influential factor. The low pH of formulations containing silica favored electrostatic interactions of VX with particles explaining the better elimination from the skin surface. Formulations containing FE had basic pH, and weak interactions with VX did not improve the skin decontamination. However, these low interactions between VX and FE promote the transfer of VX into the oil droplets in the FE-PE. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Decomposition Technology Development of Organic Component in a Decontamination Waste Solution

    International Nuclear Information System (INIS)

    Jung, Chong Hun; Oh, W. Z.; Won, H. J.; Choi, W. K.; Kim, G. N.; Moon, J. K.

    2007-11-01

    Through the project of 'Decomposition Technology Development of Organic Component in a Decontamination Waste Solution', the followings were studied. 1. Investigation of decontamination characteristics of chemical decontamination process 2. Analysis of COD, ferrous ion concentration, hydrogen peroxide concentration 3. Decomposition tests of hardly decomposable organic compounds 4. Improvement of organic acid decomposition process by ultrasonic wave and UV light 5. Optimization of decomposition process using a surrogate decontamination waste solution

  20. Decomposition Technology Development of Organic Component in a Decontamination Waste Solution

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Chong Hun; Oh, W. Z.; Won, H. J.; Choi, W. K.; Kim, G. N.; Moon, J. K

    2007-11-15

    Through the project of 'Decomposition Technology Development of Organic Component in a Decontamination Waste Solution', the followings were studied. 1. Investigation of decontamination characteristics of chemical decontamination process 2. Analysis of COD, ferrous ion concentration, hydrogen peroxide concentration 3. Decomposition tests of hardly decomposable organic compounds 4. Improvement of organic acid decomposition process by ultrasonic wave and UV light 5. Optimization of decomposition process using a surrogate decontamination waste solution.

  1. Decontamination formulation with sorbent additive

    Science.gov (United States)

    Tucker; Mark D. , Comstock; Robert H.

    2007-10-16

    A decontamination formulation and method of making that neutralizes the adverse health effects of both chemical and biological compounds, especially chemical warfare (CW) and biological warfare (BW) agents, and toxic industrial chemicals. The formulation provides solubilizing compounds that serve to effectively render the chemical and biological compounds, particularly CW and BW compounds, susceptible to attack, and at least one reactive compound that serves to attack (and detoxify or kill) the compound. The formulation includes at least one solubilizing agent, a reactive compound, a bleaching activator, a sorbent additive, and water. The highly adsorbent, water-soluble sorbent additive (e.g., sorbitol or mannitol) is used to "dry out" one or more liquid ingredients, such as the liquid bleaching activator (e.g., propylene glycol diacetate or glycerol diacetate) and convert the activator into a dry, free-flowing powder that has an extended shelf life, and is more convenient to handle and mix in the field.

  2. The magnetic and colloidal properties of CoFe2O4 nanoparticles synthesized by co-precipitation.

    Science.gov (United States)

    Gyergyek, Sašo; Drofenik, Miha; Makovec, Darko

    2014-01-01

    Magnetic CoFe(2)O(4) nanoparticles were synthesized by co-precipitation at 80 °C. This co-precipitation was achieved by the rapid addition of a strong base to an aqueous solution of cations. The investigation of the samples that were quenched at different times after the addition of the base, using transmission electron microscopy (TEM) coupled with energy-dispersive X-ray spectroscopy (EDXS) and X-ray powder diffractometry, revealed the formation of a Co-deficient amorphous phase and Co(OH)(2), which rapidly reacted to form small CoFe(2)O(4) nanoparticles. The nanoparticles grew with the time of aging at elevated temperature. The colloidal suspensions of the nanoparticles were prepared in both an aqueous medium and in a non-polar organic medium, with the adsorption of citric acid and ricinoleic acid on the nanoparticles, respectively. The measurements of the room-temperature magnetization revealed the ferrimagnetic state of the CoFe(2)O(4) nanoparticles, while their suspensions displayed superparamagnetic behaviour.

  3. Characterization of γ- Al{sub 2}O{sub 3} nanopowders synthesized by Co-precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Jbara, Ahmed S., E-mail: ahmedsbhe@yahoo.com [Center for Sustainable Nanomaterials, Universiti Teknologi Malaysia, Skudai - 81310, Johor Bahru (Malaysia); Physics Department, Science College, Al-Muthanna University, Samawah - 66001 (Iraq); Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai - 81310, Johor Bahru (Malaysia); Othaman, Zulkafli [Center for Sustainable Nanomaterials, Universiti Teknologi Malaysia, Skudai - 81310, Johor Bahru (Malaysia); Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai - 81310, Johor Bahru (Malaysia); Ati, Ali A. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai - 81310, Johor Bahru (Malaysia); Saeed, M.A., E-mail: moalsd@gmail.com [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai - 81310, Johor Bahru (Malaysia); Division of Science and Technology, University of Education, Township, Lahore - 54770 (Pakistan)

    2017-02-15

    Co-precipitation technique has been used to synthesize gamma-Al{sub 2}O{sub 3} (γ-Al{sub 2}O{sub 3}) nanopowders under annealing temperature effect. The crystalline phase and purity for the prepared powder were characterized by different spectroscopy techniques. XRD analysis confirms the gamma phase of alumina nanopowders with particle diameter ranging from 6 to 24 nm, which confirms the quantum dots formation, which is also supported by the BET measurement. The surface area of the prepared nanopowders is in the range of 109–367 m{sup 2}/g. Morphology analysis indicates that γ-Al{sub 2}O{sub 3} nanopowders are consisted of grains almost spherical in shape. Some agglomeration of nanoparticles occurs, which become more regular hexagonal shaped with the increasing annealing temperature. The small nanoparticles size and the high surface area from a simple procedure for preparing γ-Al{sub 2}O{sub 3} may make it more suitable for use as an adsorbent for malachite green. - Highlights: • Co-precipitation technique is used to synthesize gamma- Al{sub 2}O{sub 3} nanopowders. • Pure gamma- Al{sub 2}O{sub 3} phase was obtained having maximum nanoparticle size is 24 nm. • The quantum dots were formed inside powder. • High surface area of nanopowders at the low annealing temperature. • Increasing annealing temperature causes the hexagonal agglomeration shape.

  4. Phase pure synthesis of BiFeO3 nanopowders using diverse precursor via co-precipitation method

    International Nuclear Information System (INIS)

    Shami, M. Yasin; Awan, M.S.; Anis-ur-Rehman, M.

    2011-01-01

    Highlights: → Synthesized phase pure BiFeO 3 using diverse precursor by co-precipitation method. → Optimized synthesis and processing parameters. → Thermal behavior, structure and microstructure were analyzed. → Resistivity vs temperature and dielectric constant vs frequency were measured. → Multiferroicity at room temperature was confirmed by M-H and P-E loops. - Abstract: Amorphous powder of BiFeO 3 (BFO) was synthesized at low-temperature (80 deg. C) by co-precipitation method. Optimal synthesis conditions for phase pure BFO were obtained. Powders were calcined in the temperature range from 400 to 600 deg. C for 1 h. Iso-statically pressed powder was sintered at 500 deg. C for 2 h. Differential scanning calorimetric thermo-gram guided for phase transition, crystallization and melting temperatures. X-ray diffraction confirmed the amorphous nature of as synthesized powder and phase formation of calcined powders. Calcination at temperature ≥400 deg. C resulted in nano crystalline powders with perovskite structure. Average crystallite size increased with the increase in calcination temperature. Scanning electron microscopic studies revealed dense granular microstructure of the sintered samples. The sintered samples exhibited high dc resistivity at room temperature which decreased with the increase in temperature. Dielectric constant, dielectric loss tangent and ac conductivity measurements were carried out in the frequency range (10 Hz to 2 MHz). The samples responded weak electric and magnetic polarization at room temperature with unsaturated and hysteresis free loops, respectively.

  5. Development and design application of cerium (IV) decontamination process

    International Nuclear Information System (INIS)

    Bray, L.A.; Seay, J.M.

    1988-01-01

    A simple and effective method was developed for decontamination of high-level waste canisters. This method of chemical decontamination is applicable to a wide variety of contaminated equipment found in the nuclear industry. Conceptual design of the cerium [Ce(IV)] decontamination process equipment has been completed for the West Valley Demonstration project (WVDP) vitrification facility. This remote equipment, which is the first engineering scale application of this technology, will remove surface contamination from stainless-steel (SS) containers containing high-level waste (HLW) glass prior to placing them into temporary storage and ultimate shipment to a U.S. Department of Energy (DOE) repository for disposal. The objective of the development and design study was to identify an effective chemical process and to design equipment to decontaminate the HLW glass canisters to limits that meet U.S. DOE requirements. The equipment includes canister-capping and smear stations in addition to the decontamination module and associated services

  6. Development and design application of cerium (IV) decontamination process

    International Nuclear Information System (INIS)

    Bray, L.A.; Seay, J.M.

    1988-10-01

    A simple and effective method was developed for decontamination of high-level waste canisters. This method of chemical decontamination is applicable to a wide variety of contaminated equipment found in the nuclear industry. Conceptual design of the cerium [Ce(IV)] decontamination process equipment has been completed for the West Valley Demonstration Project (WVDP) vitrification facility. This remote equipment, which is the first engineering scale application of this technology, will remove surface contamination from stainless-steel (SS) containers containing high-level waste (HLW) glass prior to placing them into temporary storage and ultimate shipment to a US Department of Energy (DOE) repository for disposal. The objective of the development and design study was to identify an effective chemical process and to design equipment to decontaminate the HLW glass canisters to limits that meet USDOE requirements. The equipment includes canister-capping and smear stations in addition to the decontamination module and associated services. 2 refs., 1 fig

  7. Effect of decontamination on nuclear power plant primary circuit materials

    International Nuclear Information System (INIS)

    Brezina, M.; Kupca, L.

    1991-01-01

    The effect of repeated decontamination on the properties of structural materials of the WWER-440 primary coolant circuit was examined. Three kinds of specimens of 08Kh18Ni10T steel were used for radioactivity-free laboratory experiments; they included material obtained from assembly additions to the V-2 nuclear power plant primary piping, and a sheet of the CSN 17247 steel. Various chemical, electrochemical and semi-dry electrochemical decontamination procedures were tested. Chemical decontamination was based on the conventional AP(20/5)-CITROX(20/20) procedure and its variants; NP-CITROX type procedures with various compositions were also employed. Solutions based on oxalic acid were tested for the electrochemical and semi-dry electrochemical decontamination. The results of measurements of mass losses of the surfaces, of changes in the corrosion resistance and in the mechanical properties of the materials due to repeated decontamination are summarized. (Z.S.). 12 figs., 1 tab., 8 refs

  8. Dry decontamination for tritiated wastes

    International Nuclear Information System (INIS)

    Shi Zhengkun; Wu Tao; Dan Guiping; Xie Yun

    2009-01-01

    To aim at decontamination of tritiated wastes, we have developed and fabricated a dry tritium decontamination system, which is designed to reduce tritium surface contamination of various alloy by UV, ozone and heating. The result indicates that the elevation of temperature can obviously improve decontamination effect. With 3 h irradiation by 365 nm UV at 220 degree C, it has a decontamination rate of 99% to stainless steel surface. Ozone can more obviously improve decontamination effect when metal was heated. Ozone has a decontamination effect beyond 95% to stainless steel, aluminum and brass at 220 degree C. Tritium surface concentration of metal has a little increase after decontamination. (authors)

  9. Evaluation of Veriox as a Skin Decontamination Product after Dermal Exposure to the Nerve Agent VX

    Science.gov (United States)

    2016-09-01

    was to determine whether Veriox® had efficacy as a decontamination product (DC) after skin exposure to the chemical warfare agent VX. This study...countermeasure, decontamination , RSDL, VX, nerve agent, cutaneous exposure, chemical warfare agent 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT...invested considerable resources in developing detectors, protective garments, and products to remove and/or decontaminate chemical agent exposure on

  10. Decontamination barrier on TMI-2 leadscrew

    International Nuclear Information System (INIS)

    Baston, V.F.; Hofstetter, K.J.; Bain, G.M.; Haynerg, G.O.

    1985-01-01

    The first major component removed from the TMI-2 Reactor Vessel that has had extensive analytical examination (i.e. radiochemical, metallography, surface chemical analyses, etc.) is the H-8 leadscrew. These analyses indicate adherent cesium activity that is important to the decontamination efforts for TMI-2

  11. Decontamination techniques for buildings, structures and equipment

    International Nuclear Information System (INIS)

    Esposito, M.P.; Clark, R.

    1987-01-01

    This book provides information on pollution protection. It describes decontamination process for such pertinent pollutants as asbestos, acids, explosives, cyanides, low level radiation, pesticides, P.C.B.'s and hazardous organic chemicals. The discussions include advantages, disadvantages, cost, effectiveness of the procedures and waste disposal

  12. Control of radiation exposures by decontamination

    International Nuclear Information System (INIS)

    LeSurf, J.E.

    1981-01-01

    The radiation exposures of workers at light water and heavy water cooled reactors can be reduced by dilute chemical decontamination as exemplified by the CAN-DECON process. The cost effectiveness of the CAN-DECON process is illustrated by actual service experience and by hypothetical cases

  13. COMPILATION OF AVAILABLE DATA ON BUILDING DECONTAMINATION ALTERNATIVES

    Science.gov (United States)

    The report presents an analysis of selected technologies that have been tested for their potential effectiveness in decontaminating a building that has been attacked using biological or chemical warfare agents, or using toxic industrial compounds. The technologies selected to be ...

  14. Use of irradiation for chemical and microbial decontamination of water, wastewater and sludge. Final report of a co-ordinated research project 1995-1999

    International Nuclear Information System (INIS)

    2001-06-01

    The co-ordinated research project (CRP) was established in order to focus the attention of appropriate technical experts in integrating the effects of ionizing radiation on refractory organic pollutants and pathogenic microorganisms and parasites in the treatment of water, waste water and sewage sludge. This publication describes the findings of the CRP in three subject areas: ground water remediation, decontamination of industrial and municipal waste water and sewage sludge hygienization. This publication contains 11 individual papers from participants; each of the papers was indexed separately

  15. Mesoporous binary metal oxide nanocomposites: Synthesis, characterization and decontamination of sulfur mustard

    Energy Technology Data Exchange (ETDEWEB)

    Praveen Kumar, J., E-mail: praveenjella10@gmail.com; Prasad, G.K.; Ramacharyulu, P.V.R.K.; Singh, Beer; Gopi, T.; Krishna, R.

    2016-04-15

    Mesoporous MnO{sub 2}–ZnO, Fe{sub 2}O{sub 3}–ZnO, NiO–ZnO, and CeO{sub 2}–ZnO binary metal oxide nanocomposites were studied as sorbent decontaminants against sulfur mustard. They were synthesized by precipitation pyrolysis method and characterized by means of transmission electron microscopy, scanning electron microscopy coupled with energy dispersive analysis of X rays, X ray diffraction, and nitrogen adsorption techniques. The transmission electron microscopy and nitrogen adsorption data indicated the presence of pores with diameter ranging from 10 to 70 nm in the binary metal oxide nanocomposites and these materials exhibited surface area values in the range of 76–134 m{sup 2}/g. These binary metal oxide nanocomposites demonstrated large decontamination efficiencies against sulfur mustard when compared to their single component metal oxide nanoparticles. The binary metal oxide nanocomposites effectively decontaminated sulfur mustard into relatively non toxic products such as chloro ethyl vinyl sulfide, divinyl sulfide, 1,4-oxathiane, etc. The promising decontamination properties of binary metal oxide nanocomposites against sulfur mustard were attributed to the basic sites, Lewis acid sites, and the presence of these sites was confirmed by CO{sub 2} and NH{sub 3} temperature programmed desorption. - Graphical abstract: Mesoporous MnO{sub 2}–ZnO, Fe{sub 2}O{sub 3}–ZnO, NiO–ZnO, and CeO{sub 2}–ZnO binary metal oxide nanocomposites were studied as sorbent decontaminants against sulfur mustard. - Highlights: • Binary metal oxide nanocomposites were synthesized by co-precipitation method. • They were studied as sorbent decontaminants against sulfur mustard. • They decontaminated sulfur mustard into non toxic products. • MnO{sub 2}–ZnO and CeO{sub 2}–ZnO nanocomposites showed greater decontamination efficiency.

  16. Cold plasma decontamination using flexible jet arrays

    Science.gov (United States)

    Konesky, Gregory

    2010-04-01

    Arrays of atmospheric discharge cold plasma jets have been used to decontaminate surfaces of a wide range of microorganisms quickly, yet not damage that surface. Its effectiveness in decomposing simulated chemical warfare agents has also been demonstrated, and may also find use in assisting in the cleanup of radiological weapons. Large area jet arrays, with short dwell times, are necessary for practical applications. Realistic situations will also require jet arrays that are flexible to adapt to contoured or irregular surfaces. Various large area jet array prototypes, both planar and flexible, are described, as is the application to atmospheric decontamination.

  17. Advance in radioactive decontamination

    International Nuclear Information System (INIS)

    Basteris M, J. A.; Farrera V, R.

    2010-09-01

    The objective of the present work was to determine if the application of the Na hypochlorite has some utility in the radioactive decontamination, in comparison with the water, detergent and alcohol. Several methods were compared for decontaminate the iodine 131 and technetium 99, the work table and the skin it was carried out an initial count with the Geiger Muller. Later on, in a single occasion, the areas were washed with abundant water, alcohol, clothes detergent and sodium hypochlorite (used commercially as domestic bleacher) without diluting. Observing that the percentage in the decrease of the counted radioactivity by the Geiger Muller, decreased in the following way: It was demonstrated that the Na hypochlorite presents the highest index of radioactive decontamination with 100% of effectiveness. The Na hypochlorite is an excellent substance that can be used with effectiveness and efficiency like decontamination element in the accident cases of radioactive contamination in the clinical laboratories of nuclear medicine. (Author)

  18. Recommendations for skin decontamination

    International Nuclear Information System (INIS)

    1989-01-01

    Further to the reecommendations for determining the surface contamination of the skin and estimating the radiation exposure of the skin after contamination (SAAS-Mitt--89-16), measures for skin decontamination are recommended. They are necessary if (1) after simple decontamination by means of water, soap and brush without damaging the skin the surface contamination limits are exceeded and the radiation exposure to be expected for the undamaged healthy skin is estimated as to high, and if (2) a wound is contaminated. To remove skin contaminations, in general universally applicable, non-aggressive decontamination means and methods are sufficient. In special cases, nuclide-specific decontamination is required taking into account the properties of the radioactive substance

  19. Some remarks about decontamination

    International Nuclear Information System (INIS)

    Bertini, A.

    1990-01-01

    Decontamination in itself is not the elimination of a problem, but corresponds to move that problem from one place to another. It is beneficial only if the contamination is less of a nuisance when moved to the ''other place''. Therefore any prospective decontamination process is to be considered essentially in terms of cost-benefit, and in particular in terms of reducing the burden on the waste management systems. The paper is not intended to deal with and to review critically the technical aspects of the various decontamination processes which are currently available. Its aim is to call the attention of those who may be faced with the problem of large-scale decontamination, so that this operation is carried out after all practical aspects have been examined. (author)

  20. Food decontamination using nanomaterials

    Science.gov (United States)

    The research indicates that nanomaterials including nanoemulsions are promising decontamination media for the reduction of food contaminating pathogens. The inhibitory effect of nanoparticles for pathogens could be due to deactivate cellular enzymes and DNA; disrupting of membrane permeability; and/...

  1. Decontamination of radionuclides on construction materials

    International Nuclear Information System (INIS)

    Samuleev, P.V.; Andrews, W.S.; Creber, K.A.M.; Velicogna, D.

    2013-01-01

    A wide variety of materials can become contaminated by radionuclides, either from a terrorist attack or an industrial or nuclear accident. The final disposition of these materials depends, in large part, on the effectiveness of decontamination measures. This study reports on investigations into the decontamination of a selection of building materials. The aim has been to find an effective, easy-to-use and inexpensive decontamination system for radionuclides of cesium and cobalt, considering both the chemical and physical nature of these potential contaminants. The basic method investigated was surface washing, due to its ease and simplicity. In the present study, a basic decontamination formulation was modified by adding isotope-specific sequestering agents, to enhance the removal of cesium(I) and cobalt(II) from such construction materials as concrete, marble, aluminum and painted steel. Spiking solutions contained 134 Cs or 60 Co, which were prepared by neutron activation in the SLOWPOKE-2 nuclear reactor facility at the Royal Military College of Canada. Gamma spectroscopy was used to determine the decontamination efficiency. The results showed that the addition of sequestering agents generally improved the radiological decontamination. Although the washing of both cesium and cobalt from non-porous materials, such as aluminum and painted steel, achieved a 90-95 % removal, the decontamination of concrete and marble was more challenging, due to the porous nature of the materials. Nevertheless, the removal efficiency from 6-year-old concrete increased from 10 % to approximately 50 % for cobalt(II), and from 18 to 55 % for cesium(I), with the use of isotope binding agents, as opposed to a simple water wash. (author)

  2. Oleic-acid-coated CoFe2O4 nanoparticles synthesized by co-precipitation and hydrothermal synthesis

    International Nuclear Information System (INIS)

    Gyergyek, Sašo; Drofenik, Miha; Makovec, Darko

    2012-01-01

    Highlights: ► Synthesis of oleic-acid-coated CoFe 2 O 4 nanoparticles from an aqueous solution. ► During the co-precipitation of Co 2+ /Fe 3+ single-phase spinel forms. ► During the co-precipitation of Co 2+ /Fe 2+ , feroxyhyte forms in addition to spinel. ► Oleic acid increases the spinel formation temperature and limits particle growth. ► Colloidal suspensions of ferrimagnetic CoFe 2 O 4 were prepared. - Abstract: Oleic-acid-coated CoFe 2 O 4 nanoparticles were synthesized by co-precipitation and hydrothermal synthesis. The coprecipitation of the nanoparticles was achieved by the rapid addition of a strong base to an aqueous solution of cations in the presence of the oleic acid surfactant, or without this additive. The nanoparticles were also synthesized by a hydrothermal treatment of suspensions of the precipitates, coprecipitated at room temperature in the presence of the oleic acid, or without it. The influence of the synthesis conditions, such as the valence state of the iron cation in the starting aqueous solution, the temperature of the treatment and the presence of oleic acid, on the particles size was systematically studied. X-ray powder diffractometry (XRD) and transmission electron microscopy (TEM) coupled with energy-dispersive X-ray spectroscopy (EDS) revealed that, although spinel forms at room temperature, a substantial amount of Co was incorporated within the secondary, feroxyhyte-like phase when the iron cation was in the 2+ state. In contrast, when iron was in the 3+ state, the spinel forms at elevated temperatures of approximately 60 °C. The presence of the oleic acid further increased the formation temperature for the stoichiometric spinel. Moreover, the oleic acid impeded the particles’ growth and enabled the preparation of colloidal suspensions of the nanoparticles in non-polar organic solvents. The nanoparticles’ size was successfully controlled by the temperature of the synthesis in the region where superparamagnetism

  3. Synthesis of layered double hydroxides containing Mg2+, Zn2+, Ca2+ and Al3+ layer cations by co-precipitation methods-A review

    Science.gov (United States)

    Theiss, Frederick L.; Ayoko, Godwin A.; Frost, Ray L.

    2016-10-01

    Co-precipitation is a common method for the preparation of layered double hydroxides (LDHs) and related materials. This review article is aimed at providing newcomers to the field with some examples of the types of co-precipitation reactions that have been reported previously and to briefly investigate some of the properties of the products of these reactions. Due to the sheer volume of literature on the subject, the authors have had to limit this article to the synthesis of Mg/Al, Zn/Al and Ca/Al LDHs by co-precipitation and directly related methods. LDHs have been synthesised from various reagents including metal salts, oxides and hydroxides. Co-precipitation is also useful for the direct synthesis of LDHs with a wide range of interlayer anions and various bases have been successfully employed to prepare LDHs. Examples of other synthesis techniques including the urea method, hydrothermal synthesis and various mechanochemical methods that are undoubtedly related to co-precipitation have also been included in this review. The effect of post synthesis hydrothermal has also been summarised.

  4. Research and development activities of the Institut fuer Nukleare Entsorgungstechnik on the decontamination of surfaces

    International Nuclear Information System (INIS)

    Dippel, T.; Hentschel, D.; Kunze, S.

    1983-06-01

    After developing a procedure for the ''Testing of Surface Coating Materials for the Decontamination'' about 900 different surface coating materials had been tested and evaluated for the domestic and foreign industry. The results prove the following basic facts: Surface coatings, low in porosity, forming a smooth surface and containing limited amounts of filler are in the majority very effectively decontaminated if they are prepared of chemically stable, water repellent materials; Decontamination results are drastically poorer if the degree of filling of the materials is high especially if hygroscopic fillers and/or hygroscopic colouring matters are used. Currently available cleansers and washing powders used for decontamination did not fulfill the three basic demands for a decontamination agent: high efficiency, small foam generation and sufficient thermal stability. Therefore for the decontamination of walls, floors, etc. a water delutable, liquid cleanser was developed. In the same context a washing powder was optimized for the decontamination of contaminated clothing. The experiments on the decontamination of stainless steels ended up with the formulation of a pickling paste. Furthermore all investigations were aimed at a minimization of the waste generation by the decontamination process. This resulted in decontamination techniques, in which the decontaminating agents were applied in thin layers. A comparison of the currently practiced dipping technique with the coating technique showed that the latter one gave the better decontamination results and that the amount of decontamination waste was reduced. (orig./HP) [de

  5. Decommissioning and Decontamination

    International Nuclear Information System (INIS)

    Massaut, V.

    2000-01-01

    The objectives of SCK-CEN's decommissioning and decontamination programme are (1) to develop, test and optimise the technologies and procedures for decommissioning and decontamination of nuclear installations in order to minimise the waste arising and the distributed dose; (2) to optimise the environmental impact; (3) to reduce the cost of the end-of-life of the installation; (4) to make these new techniques available to the industry; (5) to share skills and competences. The programme and achievements in 1999 are summarised

  6. Facility decontamination technology workshop

    International Nuclear Information System (INIS)

    1980-10-01

    Purpose of the meeting was to provide a record of experience at nuclear facilities, other than TMI-2, of events and incidents which have required decontamination and dose reduction activities, and to furnish GPU and others involved in the TMI-2 cleanup with the results of that decontamination and dose reduction technology. Separate abstracts were prepared for 24 of the 25 papers; the remaining paper had been previously abstracted

  7. Special zone territory decontamination

    International Nuclear Information System (INIS)

    Samojlenko, Yu.N.; Golubev, V.V.

    1989-01-01

    Special zone is the Chernobyl' NPP operating site (OS). OS decontamination is described including reactor ruins from the accident moment. The process was begun from reactor bombardment with absorbing and filtering materials (sand, clay, lead, boron compounds). Then were produced soil shovelling, territory filling by dry concrete and laying concrete layer with thickness up to 300 mm. NPP room and equipment decontamination is described. 3 figs.; 3 tabs

  8. Facility decontamination technology workshop

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-10-01

    Purpose of the meeting was to provide a record of experience at nuclear facilities, other than TMI-2, of events and incidents which have required decontamination and dose reduction activities, and to furnish GPU and others involved in the TMI-2 cleanup with the results of that decontamination and dose reduction technology. Separate abstracts were prepared for 24 of the 25 papers; the remaining paper had been previously abstracted. (DLC)

  9. Coolant system decontamination

    International Nuclear Information System (INIS)

    Anstine, L.D.; James, D.B.; Melaika, E.A.; Peterson, J.P.

    1981-01-01

    An improved method for decontaminating the coolant system of water cooled nuclear power reactors and for regenerating the decontamination solution is described. A small amount of one or more weak-acid organic complexing agents is added to the reactor coolant, and the pH is adjusted to form a decontamination solution which is circulated throughout the coolant system to dissolve metal oxides from the interior surfaces and complex the resulting metal ions and radionuclide ions. The coolant containing the complexed metal ions and radionuclide ions is passed through a strong-base anion exchange resin bed which has been presaturated with a solution containing the complexing agents in the same ratio and having the same pH as the decontamination solution. As the decontamination solution passes through the resin bed, metal-complexed anions are exchanged for the metal-ion-free anions on the bed, while metal-ion-free anions in the solution pass through the bed, thus removing the metal ions and regenerating the decontamination solution. (author)

  10. Decontamination of radioactive process waste water by foam separation. Vol. 3

    International Nuclear Information System (INIS)

    Shakir, K.; Aziz, M.; Beheir, Sh.G.; Benyamin, K.; Samy, S.; Salama, H.N.

    1996-01-01

    On the basis of new studies and previous work from this laboratory, several foam separation techniques are considered feasible methods to carry out the separation of radioactive nuclides from simulated radioactive process waste water. Anionic or cationic collectors were used depending on the type of charge on the ion or precipitate to be removed. Sodium lauryl sulphate, aerosol-18 potassium oleate, acetyl trimethyl ammonium bromide, dodecyl pyridinium chloride and gelation were examined as the collector. Aluminium hydroxide, iron (III) oxyhydroxide and hydrous manganese dioxide were studied as the adsorbing floc adsorbing colloid flotation and copper ferrocyanide as the co precipitating agent in co precipitate flotation. The effects of varying the collector, the adsorbing colloid floc, co precipitant and metal ion concentrations, the PH, the gas flow rate, the ionic strength, length of the flotation column and multistage separation on the percentage removal, volume reduction and enrichment ratio were investigated. According to experimental results, adsorbing colloid flotation, whenever applicable, is the preferred method for decontamination. Radionuclide removal up to 100% were obtained. 4 figs., 13 tabs

  11. Decontamination of radioactive process waste water by foam separation. Vol. 3

    Energy Technology Data Exchange (ETDEWEB)

    Shakir, K; Aziz, M; Beheir, Sh G; Benyamin, K; Samy, S; Salama, H N [Nuclear Chemistry, and Radiation Protection Departments, Hot Laboratories and Nuclear Research Centers, atomic Energy Authority, P.O. Box 13759, Cairo (Egypt)

    1996-03-01

    On the basis of new studies and previous work from this laboratory, several foam separation techniques are considered feasible methods to carry out the separation of radioactive nuclides from simulated radioactive process waste water. Anionic or cationic collectors were used depending on the type of charge on the ion or precipitate to be removed. Sodium lauryl sulphate, aerosol-18 potassium oleate, acetyl trimethyl ammonium bromide, dodecyl pyridinium chloride and gelation were examined as the collector. Aluminium hydroxide, iron (III) oxyhydroxide and hydrous manganese dioxide were studied as the adsorbing floc adsorbing colloid flotation and copper ferrocyanide as the co precipitating agent in co precipitate flotation. The effects of varying the collector, the adsorbing colloid floc, co precipitant and metal ion concentrations, the PH, the gas flow rate, the ionic strength, length of the flotation column and multistage separation on the percentage removal, volume reduction and enrichment ratio were investigated. According to experimental results, adsorbing colloid flotation, whenever applicable, is the preferred method for decontamination. Radionuclide removal up to 100% were obtained. 4 figs., 13 tabs.

  12. and aluminum-substituted cobalt ferrite prepared by co-precipitation ...

    Indian Academy of Sciences (India)

    Spinal ferrites having the general formula Co1-ZnFe2-AlO4 ( = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6) were prepared using the wet chemical co-operation technique. The samples were annealed at 800°C for 12 h and were studied by means of X-ray diffraction, magnetization and low field AC susceptibility measurements.

  13. Decontamination tests on tritium-contaminated materials

    International Nuclear Information System (INIS)

    Boutot, P.; Schipfer, P.

    1967-01-01

    These tests are designed to try out various processes liable to be applied to the decontamination of a material contaminated with tritium. The samples are thin stainless- steel slabs contaminated in the laboratory with elements extracted from industrial installations. The measurement of the initial and residual activities is carried out using an open-window BERTHOLD counter. The best results are obtained by passing a current of pre-heated (300 deg. C) air containing water vapour. This process makes it possible to reach a decontamination factor of 99.5 per cent in 4 hours. In a vacuum, the operation has to be prolonged to 100 hours in order to obtain a decontamination factor of 99.2 per cent. Wet-chemical or electrolytic treatments are efficient but their use is limited by the inherent corrosion risks. A study of the reappearance of the contamination has made it possible to observe that this phenomenon occurs whatever the process used. (authors) [fr

  14. Study of magnetic and electrical properties of La doped Mn-Zn nanoferrites synthesized by co-precipitation technique

    International Nuclear Information System (INIS)

    Panwar, Neena; Thakur, Atul; Thakur, Preeti

    2013-01-01

    Lanthanum manganese zinc ferrite powder of the composition Mn 0.4 Zn 0.6 La 0.4 Fe 1.6 O 4 were synthesized via co-precipitation technique. Metallic chlorides of manganese, zinc and iron in which Lanthanum is doped were taken. Sodium hydroxide (NaOH) base was used as precipitant agent. The calcinations (presintering) were performed at 700℃ for 3h and sintering at different temperatures 900℃, 850℃, 800℃ also for 3h. The structural investigation of the prepared sample was performed with X-ray diffraction (XRD) and scanning electron microscope (SEM). For studying magnetic properties vibrating sample magnetometer (VSM) are used. Electrical properties were studied by DC resistivity set up. (author)

  15. Properties of Er{sub 2}O{sub 3} nanoparticles synthesized by a modified co-precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Castaneda C, J.; Maranon R, V. F.; Perez Ladron de G, H.; Rodriguez R, R. A.; Chiu Z, R. [Universidad de Guadalajara, Centro Universitario de los Lagos, Av. Enrique Diaz de Leon s/n, Lagos de Moreno 47460, Jalisco (Mexico); Meneses N, M. A., E-mail: jcc050769@yahoo.com.mx [Centro de Investigaciones en Optica, A. C., Apdo. Postal 1-948, Leon, Guanajuato (Mexico)

    2015-07-01

    Er{sub 2}O{sub 3} nanoparticles were synthesized by co-precipitation with the addition of ascorbate as stabilizing agent. The nanoparticles had spherical shapes with a mean diameter of 32 nm and were allocated in clusters, as determined by X-ray diffraction, atomic force microscopy and optical microscopy. Characteristic green and red emissions from Er{sup 3+} were recorded by pumping the nanoparticles at 525 nm, 805 nm and 975 nm. However, the luminescence spectra show an enhancement of red emission for Nir pump wavelengths. We proposed this behavior was due to phonon-assisted depopulation mechanisms and energy transfer processes related to the different excitation schemes. (Author)

  16. Upconversion emission study of Er3+/Yb3+ doped barium titanate phosphor prepared by co-precipitation method

    International Nuclear Information System (INIS)

    Mahata, M.K.; Dey, R.; Kumar, K.; Rai, V.K.; Rai, S.B.

    2012-01-01

    In the present work we have successfully synthesized the Er 3+ , Yb 3+ doped barium titanate phosphor via co-precipitation synthesis method. Under 980 nm excitation, tri-color upconversion fluorescence has been observed. The Fourier Transform Infrared measurement was done to check the presence of organic impurities. In order to find out how many photons are involved in each emission band, the variation of UC emission intensity of the codoped phosphor is studied with increase in excitation power. Upconversion emission spectra show that as the annealing temperature of the powder is increased, intensity of red emission decreases and intensity of green emission increases due to the decrease in maximum phonon frequency of the host material. (author)

  17. Room Temperature Co-Precipitation Synthesis of Magnetite Nanoparticles in a Large pH Window with Different Bases.

    Science.gov (United States)

    Mascolo, Maria Cristina; Pei, Yongbing; Ring, Terry A

    2013-11-28

    Magnetite nanoparticles (Fe₃O₄) represent the most promising materials in medical applications. To favor high-drug or enzyme loading on the nanoparticles, they are incorporated into mesoporous materials to form a hybrid support with the consequent reduction of magnetization saturation. The direct synthesis of mesoporous structures appears to be of interest. To this end, magnetite nanoparticles have been synthesized using a one pot co-precipitation reaction at room temperature in the presence of different bases, such as NaOH, KOH or (C₂H₅)₄NOH. Magnetite shows characteristics of superparamagnetism at room temperature and a saturation magnetization (Ms) value depending on both the crystal size and the degree of agglomeration of individual nanoparticles. Such agglomeration appears to be responsible for the formation of mesoporous structures, which are affected by the pH, the nature of alkali, the slow or fast addition of alkaline solution and the drying modality of synthesized powders.

  18. Room Temperature Co-Precipitation Synthesis of Magnetite Nanoparticles in a Large pH Window with Different Bases

    Directory of Open Access Journals (Sweden)

    Maria Cristina Mascolo

    2013-11-01

    Full Text Available Magnetite nanoparticles (Fe3O4 represent the most promising materials in medical applications. To favor high-drug or enzyme loading on the nanoparticles, they are incorporated into mesoporous materials to form a hybrid support with the consequent reduction of magnetization saturation. The direct synthesis of mesoporous structures appears to be of interest. To this end, magnetite nanoparticles have been synthesized using a one pot co-precipitation reaction at room temperature in the presence of different bases, such as NaOH, KOH or (C2H54NOH. Magnetite shows characteristics of superparamagnetism at room temperature and a saturation magnetization (Ms value depending on both the crystal size and the degree of agglomeration of individual nanoparticles. Such agglomeration appears to be responsible for the formation of mesoporous structures, which are affected by the pH, the nature of alkali, the slow or fast addition of alkaline solution and the drying modality of synthesized powders.

  19. Structure and electrochemical properties of Mg2SnO4 nanoparticles synthesized by a facile co-precipitation method

    International Nuclear Information System (INIS)

    Tang, Hao; Cheng, Cuixia; Yu, Gaige; Liu, Haowen; Chen, Weiqing

    2015-01-01

    Nanosized Mg 2 SnO 4 has been synthesized by a facile co-precipitation method. The structure and morphology of the as-prepared samples are characterized by X-ray diffraction (XRD), X-ray photoelectron spectrometer (XPS), fourier Transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). It is found that Mg 2 SnO 4 sample is very sensitive to the aging time of the precursor. The single phase Mg 2 SnO 4 nanoparticles with ∼23 nm can be obtained at 900 °C using the aging 35 min percusor as source. The electrochemical properties of the powder obtained at 900 °C are investigated by galvanostatic discharge-charge tests and cyclic voltammograms (CVs). The initial specific discharge capacity reaches as high as 927.7 mAh g −1 at 0.2 mA cm −2 in 0.05–3.0 V, which indicates that Mg 2 SnO 4 nanoparticles could be a promising candidate of anode material for Li-ion batteries. - Highlights: • Nanosized Mg 2 SnO 4 has been synthesized by a facile co-precipitation method. • We find that Mg 2 SnO 4 sample is very sensitive to the ageing time of the precursor. • The single phase Mg 2 SnO 4 nanoparticles with about 23 nm can be obtained by calcining the ageing 35 min percusor at 900 °C. • The obtained powders show a better electrochemical performance

  20. Synthesis, Characterization, and Atenolol Delivery Application of Functionalized Mesoporous Hydroxyapatite Nanoparticles Prepared by Microwave-Assisted Co-precipitation Method.

    Science.gov (United States)

    Mortazavi-Derazkola, Sobhan; Naimi-Jamal, Mohammad Reza; Ghoreishi, Seyedeh Masoumeh

    2016-01-01

    Atenolol has been used to treat angina and hypertension, either alone or with other antihypertensives. Despite its usefulness, it shows some side effects such as diarrhea and nausea in some patients. A method for slow release of atenolol in intestine is helpful to prevent such side effects. A facile co-precipitation microwave-assisted method was used to fabricate mesoporous hydroxyapatite nanoparticles (mHAp). It was then functionalized to have SO3H groups. The synthesized material was used for storage/slow release study of atenolol. Atenolol loaded mHAp shows immediate release of atenolol in pH 8, whileafter functionalizing shows up to ca. 30% release at the beginning. In pH 1, 50% of drug was released after 10 h from AT@mHAp and after 18h the drug was almost completely released.The drug release profiles of functionalized HAp at pH value 1 and 8reveals the complete release of atenolol in intestine pH, while no complete release is observed in stomach environment. The aims of this work were synthesis and characterization of mesoporous HAp through the microwave-assisted co-precipitation method and elucidate the underlying drug release capability of mesoporous HAp nanoparticles. The SO3H group was incorporated into the mesoporous HAp and then used as drug delivery carriers using atenolol as a model drug to investigate their drug storage/release properties in simulated body fluid (SBF). Increasing pH value to 8 causes increase in the drug release.

  1. Decontamination of Belarus research reactor installation by strippable coatings

    International Nuclear Information System (INIS)

    Voronik, N.I.; Shatilo, N.N.

    2002-01-01

    The goal of this study was to develop new strippable coatings using water-based solutions of polyvinyl alcohol and active additives for decontamination of research reactor equipment. The employment of strippable coatings makes it possible to minimize the quantity of liquid radioactive waste. The selection of strippable decontaminating coatings was carried out on the basis of general requirements to decontaminating solutions: successfully dissolve corrosion deposits; ensure the desorption of radionuclides from the surfaces and the absence of resorption; introduce minimal corrosion effect of construction materials; to be relatively cheap and available in reagents. The decontaminating ability and adhesion properties of these coatings depending on metal and deposit sorts were investigated. Research on the chemical stability of solid wastes was carried out. The data obtained were the base for recommendations on waste management procedure for used films and pastes. A full-scale case-study analysis was performed for comparing strippable coatings with decontaminating solutions. (author)

  2. Thermoluminescence and photoluminescence properties of NaCl:Mn, NaCL:Cu nano-particles produced using co-precipitation and sono-chemistry methods

    Energy Technology Data Exchange (ETDEWEB)

    Mehrabi, M. [Faculty of Physics, University of Kashan, Kashan (Iran, Islamic Republic of); Zahedifar, M. [Faculty of Physics, University of Kashan, Kashan (Iran, Islamic Republic of); Institute of Nanosince and Nanotechnology, University of Kashan, Kashan (Iran, Islamic Republic of); Saeidi-Sogh, Z. [Institute of Nanosince and Nanotechnology, University of Kashan, Kashan (Iran, Islamic Republic of); Ramazani-Moghaddam-Arani, A., E-mail: ramazmo@kashanu.ac.ir [Institute of Nanosince and Nanotechnology, University of Kashan, Kashan (Iran, Islamic Republic of); Sadeghi, E. [Faculty of Physics, University of Kashan, Kashan (Iran, Islamic Republic of); Institute of Nanosince and Nanotechnology, University of Kashan, Kashan (Iran, Islamic Republic of); Harooni, S. [Institute of Nanosince and Nanotechnology, University of Kashan, Kashan (Iran, Islamic Republic of)

    2017-02-21

    The NaCl: Cu and NaCl: Mn nanoparticles (NPs) were produced by co-precipitation and sono-chemistry methods and their thermoluminescence (TL) and photoluminescence (PL) properties were studied. By decreasing the particles size a considerable increase in sensitivity of the samples to high dose gamma radiation was observed. The NPs produced by sono-chemistry method have smaller size, homogeneous structure, more sensitivity to high gamma radiation and less fading than of those produced by co-precipitation method.

  3. Archives decontamination by gamma irradiation

    International Nuclear Information System (INIS)

    Bratu, E.; Moise, I.V.; Cutrubinis, M.; Negut, D.C.; Virgolici, Marian

    2009-01-01

    The treatment of archives with gamma irradiation is an efficient and environmental friendly alternative for biological decontamination of large volume of archives. It substitutes the use of chemicals for conservation and contributes to safer workplaces. This work is targeting documents from recent archives where the value of information is not obsolete and may become an important historical and cultural testimony. For a successful treatment, an optimal absorbed dose has to be established. An excessive dose may damage papers and an insufficient one will not reduce bioburden to the desired level. An interdisciplinary team was performing various physical and chemical tests in order to evaluate deterioration of paper at high doses. In the case of natural disaster, it is not excluded the '' emergency '' treatment for documents in immediate danger of total destruction. (authors)

  4. Gentilly 1: decontamination program

    International Nuclear Information System (INIS)

    Le, H.; Denault, P.

    1985-01-01

    The Gentilly 1 station, a 250-MW(e) light-water-cooled and heavy-water-moderated nuclear reactor, is being decommissioned to a static state (variant of stage 1) condition by Atomic Energy of Canada Limited (AECL). The scope of the decontamination program at the Gentilly 1 site includes the fuel pool and associated systems, the decontamination center, the laundry, the feedwater pumps and piping systems, the service building ventilation and drainage systems, and miscellaneous floor and wall areas. After an extensive literature review for acceptable decontamination methods, it was decided that the decontamination equipment used at Gentilly 1 during the program would include a hydrolaser, a scarifier, chipping hammers, a steam cleaner, an ultrasonic bath, and cutting tools. In addition, various foams, acids, detergents, surfactants, and abrasives are used alone and in tandem with the above equipment. This paper highlights the result of these decontaminations, their effectiveness, and the recommendation for future application. The methodology in performing these operations are also presented

  5. Modification the Oxalic Co-precipitation Method on a Novel Catalyst Cu/Zn/Al2O3/Cr2O3 for Autothermal Reforming Reaction of Methanol

    Directory of Open Access Journals (Sweden)

    Cheng- Hsin Kuo

    2013-12-01

    Full Text Available This study addresses the catalytic performance of Cu/ZnO/Al2O3/Cr2O3 in low-temperature of autothermal reforming (ATR reaction. Various operating conditions were used to decide the optimum reaction conditions: type of promoter (ZrO2, CeO2, and Cr2O3, precipitation temperature, precipitation pH, operation temperature, molar ratio of O2/CH3OH (O/C, and weight hourly space velocity (WHSV. The catalysts were prepared using the oxalic coprecipitation method. Characterization of the catalyst was conducted using a porosity analyzer, XRD, and SEM. The methanol conversion and volumetric percentage of hydrogen using the best catalyst (Cu/ZnO/Al2O3/Cr2O3 exceeded 93% and 43%, respectively. A catalyst prepared by precipitation at -5 oC and at pH of 1 converted methanol to 40% H2 and less than 3000 ppm CO at reaction temperature of 200 oC. The size and dispersion of copper and the degradation rate and turnover frequency of the catalyst was also calculated. Deactivation of the Cu catalyst at a reaction temperature of 200 oC occurred after 30 h. © 2013 BCREC UNDIP. All rights reservedReceived: 8th May 2013; Revised: 10th August 2013; Accepted: 18th August 2013[How to Cite: Cheng, H.K., Lesmana, D., Wu, H.S. (2013. Modification the Oxalic Co-precipitation Method on a Novel Catalyst Cu/Zn/Al2O3/Cr2O3 for Autothermal Reforming Reaction of Methanol. Bulletin of Chemical Reaction Engineering & Catalysis, 8 (2: 110-124. (doi:10.9767/bcrec.8.2.4844.110-124][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.8.2.4844.110-124

  6. Structural, electrical, magnetic and dielectric properties of rare-earth substituted cobalt ferrites nanoparticles synthesized by the co-precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Nikumbh, A.K., E-mail: aknik@chem.unipune.ac.in; Pawar, R.A.; Nighot, D.V.; Gugale, G.S.; Sangale, M.D.; Khanvilkar, M.B.; Nagawade, A.V.

    2014-04-15

    Pure nanoparticles of the rare-earth substituted cobalt ferrites CoRE{sub x}Fe{sub 2−x}O{sub 4} (where RE=Nd, Sm and Gd and x=0.1 and 0.2) were prepared by the chemical co-precipitation method. X-ray diffraction, Transmission electron microscopy (TEM), d.c. electrical conductivity, Magnetic hysteresis and Thermal analysis are utilized in order to study the effect of variation in the rare-earth substitution and its impact on particle size, magnetic properties like M{sub S}, H{sub C} and Curie temperature. The phase identification of the materials by X-ray diffraction reveals the single-phase nature of the materials. The lattice parameter increased with rare-earth content for x≤0.2. The Transmission electron micrographs of Nd-, Sm- and Gd-substituted CoFe{sub 2}O{sub 4} exhibit the particle size 36.1 to 67.8 nm ranges. The data of temperature variation of the direct current electrical conductivity showed definite breaks, which corresponds to ferrimagnetic to paramagnetic transitions. The thermoelectric power for all compound are positive over the whole range of temperature. The dielectric constant decreases with frequency and rare-earth content for the prepared samples. The magnetic properties of rare-earth substituted cobalt ferrites showed a definite hysteresis loop at room temperature. The reduction of coercive force, saturation magnetization, ratio M{sub R}/M{sub S} and magnetic moments may be due to dilution of the magnetic interaction.

  7. Magnetic and structural properties of Cu{sub 0.85}Fe{sub 0.15}O system synthesized by co-precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Colorado, H. D., E-mail: herdacom@gmail.com; Perez Alcazar, G. A. [Universidad del Valle, Departamento de Fisica (Colombia)

    2011-11-15

    Cu{sub 0.94}Fe{sub 0.06}O and Cu{sub 0.85}Fe{sub 0.15}O samples were synthesized by using the co-precipitation chemical method. Starting from aqueous solutions of copper nitrate, CuO (NO{sub 3}){sub 2} 3H{sub 2}O, iron nitrate, Fe (NO{sub 3}){sub 3} 9H{sub 2}O and sodium hydroxide as precipitating agent, NaOH. The precipitate of three samples for Cu{sub 0.94}Fe{sub 0.06}O and five for Cu{sub 0.85}Fe{sub 0.15}O of fine powder were calcined for 5 h at different temperatures. The obtained X rays diffraction patterns refined by the Rietveld method show the CuO characteristic pattern, showing that the Fe atoms enter to replace Cu atoms. Furthermore, it was obtained that the crystallite size decreases with calcination temperatures for Cu{sub 0.94}Fe{sub 0.06}O. The transmission Moessbauer spectroscopy showed that the samples present a disordered paramagnetic behavior due to the big value of the half-width of line of the quadrupolar splitting. Vibrating sample magnetometry confirms the paramagnetic character. The XRD results indicate that the material is nanostructured, due that the crystallite sizes are of the order of 10 nm for Cu{sub 0.94}Fe{sub 0.06}O and 40 nm for Cu{sub 0.85}Fe{sub 0.15}O.

  8. Bacterial decontamination using ambient pressure nonthermal discharges

    Energy Technology Data Exchange (ETDEWEB)

    Birmingham, J.G.; Hammerstrom, D.J.

    2000-02-01

    Atmospheric pressure nonthermal plasmas can efficiently deactivate bacteria in gases, liquids, and on surfaces, as well as can decompose hazardous chemicals. This paper focuses on the changes to bacterial spores and toxic biochemical compounds, such as mycotoxins, after their treatment in ambient pressure discharges. The ability of nonthermal plasmas to decompose toxic chemicals and deactivate hazardous biological materials has been applied to sterilizing medical instruments, ozonating water, and purifying air. In addition, the fast lysis of bacterial spores and other cells has led us to include plasma devices within pathogen detection instruments, where nucleic acids must be accessed. Decontaminating chemical and biological warfare materials from large, high value targets such as building surfaces, after a terrorist attack, are especially challenging. A large area plasma decontamination technology is described.

  9. TMI-2 containment decontamination plans

    International Nuclear Information System (INIS)

    McDougall, F.

    1980-01-01

    Because of other priorities such as reentry, purging, and recovery, containment decontamination is only in the preliminary planning stages. This paper summarizes the study with emphasis on the remote decontamination techniques

  10. Radioactive contamination of some rubber or plastic surfaces by fission products. Decontamination tests; Contamination radioactive de quelques surfaces en caoutchouc ou en matiere plastique par des produits de fission. Essais de decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Mestre, E.; Sautiez, N.

    1957-10-15

    With the objective of notably addressing the contamination and decontamination of gloves and floor covering, this report first presents some characteristics of contaminating radioactive materials (nature, physical and chemical condition), of contaminated surfaces (surface condition, surface nature), and of decontamination processes (physical, chemical or mechanical action). It describes the operational modality implemented to test decontamination processes on various glove or flooring materials: sample preparation, counting, decontamination, reproducibility of decontamination tests, results in terms of activity reduction. It more precisely describes the tested samples: short gloves, gloves from glove boxes, floor and wall coverings. Results are presented and discussed in terms of sample susceptibility to contamination, and of decontamination, but also for re-contamination tests after a Nab-based decontamination (susceptibility to contamination, decontamination gain)

  11. Decontamination of main coolant pumps

    International Nuclear Information System (INIS)

    Roofthooft, R.

    1988-01-01

    Last year a number of main coolant pumps in Belgian nuclear power plants were decontaminated. A new method has been developed to reduce the time taken for decontamination and the volume of waste to be treated. The method comprises two phases: Oxidation with permanganate in nitric acid and dissolution in oxalic acid. The decontamination of main coolant pumps can now be achieved in less than one day. The decontamination factors attained range between 15 and 150. (orig.) [de

  12. Planning guidance for nuclear-power-plant decontamination. [PWR; BWR

    Energy Technology Data Exchange (ETDEWEB)

    Munson, L.F.; Divine, J.R.; Martin, J.B.

    1983-06-01

    Direct and indirect costs of decontamination are considered in the benefit-cost analysis. A generic form of the benefit-cost ratio is evaluated in monetary and nonmonetary terms, and values of dollar per man-rem are cited. Federal and state agencies that may have jurisiction over various aspects of decontamination and waste disposal activities are identified. Methods of decontamination, their general effectiveness, and the advantages and disadvantages of each are outlined. Dilute or concentrated chemical solutions are usually used in-situ to dissolve the contamination layer and a thin layer of the underlying substrate. Electrochemical techniques are generally limited to components but show high decontamination effectiveness with uniform corrosion. Mechanical agents are particularly appropriate for certain out-of-system surfaces and disassembled parts. These processes are catagorized and specific concerns are discussed. The treatment, storage, and disposal or discharge or discharge of liquid, gaseous, and solid wastes generated during the decontamination process are discussed. Radioactive and other hazardous chemical wastes are considered. The monitoring, treatment, and control of radioactive and nonradioactive effluents, from both routine operations and possible accidents, are discussed. Protecting the health and safety of personnel onsite during decontamination is of prime importance and should be considered in each facet of the decontamination process. The radiation protection philosophy of reducing exposure to levels as low as reasonably achievable should be stressed. These issues are discussed.

  13. Effect of Cerium(IV)-Surfactant Reaction in Foam Decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Han Beom; Jung, Chong-Hun; Yoon, In-Ho; Kim, Chorong; Choi, Wang-Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    Using foams allows the decommissioning of complex shaped facilities. The decontamination foam comprises at least one surfactant to generate the foam and one or more chemical reactants to achieve the dissolution of the contaminants at the solid surface. In order to improve the efficiency of decontamination foam, the present study attempts to find the optimum condition of chemical reagents to the foaming solution. The corrosion rate of radioactive nuclides contaminated stainless steel metal is very important factor for the foam decontamination process. The goal of this study is to develop the decontamination process for contaminated stainless steel in medium of nitric acid. Stainless steel needs a strong oxidizing agent such as Ce(IV) ion and the effects of cerium(IV). Surfactant interaction involved in foam decontamination and finally the improvement brought by formulation science. The formulation of foams loaded with strong oxidizing reagents such as Ce(IV) is an important factor. The enhanced decontamination properties of nitric acid with Ce(IV) additive on stainless steel is well known in liquid mediums. stainless steel metal is an important aspect in the foam decontamination process.

  14. Effect of Cerium(IV)-Surfactant Reaction in Foam Decontamination

    International Nuclear Information System (INIS)

    Yang, Han Beom; Jung, Chong-Hun; Yoon, In-Ho; Kim, Chorong; Choi, Wang-Kyu

    2015-01-01

    Using foams allows the decommissioning of complex shaped facilities. The decontamination foam comprises at least one surfactant to generate the foam and one or more chemical reactants to achieve the dissolution of the contaminants at the solid surface. In order to improve the efficiency of decontamination foam, the present study attempts to find the optimum condition of chemical reagents to the foaming solution. The corrosion rate of radioactive nuclides contaminated stainless steel metal is very important factor for the foam decontamination process. The goal of this study is to develop the decontamination process for contaminated stainless steel in medium of nitric acid. Stainless steel needs a strong oxidizing agent such as Ce(IV) ion and the effects of cerium(IV). Surfactant interaction involved in foam decontamination and finally the improvement brought by formulation science. The formulation of foams loaded with strong oxidizing reagents such as Ce(IV) is an important factor. The enhanced decontamination properties of nitric acid with Ce(IV) additive on stainless steel is well known in liquid mediums. stainless steel metal is an important aspect in the foam decontamination process

  15. Decontamination of CAGR gas circulator components

    International Nuclear Information System (INIS)

    Rogers, L.N.; Hooper, A.J.

    1985-01-01

    This paper describes the development and full-scale trial of two methods for removal of radioactive contamination on the surfaces of CAGR gas circulator components. The two methods described are a particle impact cleaning (PIC) decontamination technique and an electrochemical technique, 'electro-swabbing', which is based on the principle of decontamination by electro-polishing. In developing these techniques it was necessary to take account of the physical and chemical nature of the surface deposits on the gas circulator components; these were shown to consist of magnetite-type oxide and carbonaceous material. In order to follow the progress of the decontamination it was also necessary to develop a surface sampling technique which was effective and precise under these conditions; an electrochemical technique, employing similar principles to the electro-swabbing process, was developed for this purpose. The full-scale trial of the PIC decontamination technique was carried out on an inlet guide vane (IGV) assembly, this having been identified as the component from the gas circulator which contributes most to the radiation dose accumulated during routine circulator maintenance. The technique was shown to be practically viable and some 99% of the radioactive contamination was readily removed from the treated surfaces with only negligible surface damage being caused. The full-scale trial of the electro-swabbing decontamination technique was carried out on a gas circulator impeller. High decontamination factors were again achieved with ≥ 99% of the radioactive contamination being removed from the treated surfaces. The technique has practical limitations in terms of handling and treatment of waste-arisings. However, the use of specially-designed swabbing electrodes may allow the treatment of constricted geometries inaccessible to techniques such as PIC. The technique is also highly suitable for the treatment of soft-finish materials and of components fabricated from a

  16. A survey of decontamination processes applicable to DOE nuclear facilities

    Energy Technology Data Exchange (ETDEWEB)

    Chen, L.; Chamberlain, D.B.; Conner, C.; Vandegrift, G.F.

    1997-05-01

    The objective of this survey was to select an appropriate technology for in situ decontamination of equipment interiors as part of the decommissioning of U.S. Department of Energy nuclear facilities. This selection depends on knowledge of existing chemical decontamination methods. This report provides an up-to-date review of chemical decontamination methods. According to available information, aqueous systems are probably the most universally used method for decontaminating and cleaning metal surfaces. We have subdivided the technologies, on the basis of the types of chemical solvents, into acid, alkaline permanganate, highly oxidizing, peroxide, and miscellaneous systems. Two miscellaneous chemical decontamination methods (electrochemical processes and foam and gel systems) are also described. A concise technical description of various processes is given, and the report also outlines technical considerations in the choice of technologies, including decontamination effectiveness, waste handing, fields of application, and the advantages and limitations in application. On the basis of this survey, six processes were identified for further evaluation. 144 refs., 2 tabs.

  17. A survey of decontamination processes applicable to DOE nuclear facilities

    International Nuclear Information System (INIS)

    Chen, L.; Chamberlain, D.B.; Conner, C.; Vandegrift, G.F.

    1997-05-01

    The objective of this survey was to select an appropriate technology for in situ decontamination of equipment interiors as part of the decommissioning of U.S. Department of Energy nuclear facilities. This selection depends on knowledge of existing chemical decontamination methods. This report provides an up-to-date review of chemical decontamination methods. According to available information, aqueous systems are probably the most universally used method for decontaminating and cleaning metal surfaces. We have subdivided the technologies, on the basis of the types of chemical solvents, into acid, alkaline permanganate, highly oxidizing, peroxide, and miscellaneous systems. Two miscellaneous chemical decontamination methods (electrochemical processes and foam and gel systems) are also described. A concise technical description of various processes is given, and the report also outlines technical considerations in the choice of technologies, including decontamination effectiveness, waste handing, fields of application, and the advantages and limitations in application. On the basis of this survey, six processes were identified for further evaluation. 144 refs., 2 tabs

  18. Electrokinetic decontamination of concrete

    Energy Technology Data Exchange (ETDEWEB)

    Lomasney, H. [ISOTRON Corp., New Orleans, LA (United States)

    1995-10-01

    The U.S. Department of Energy has assigned a priority to the advancement of technology for decontaminating concrete surfaces which have become contaminated with radionuclides, heavy metals, and toxic organics. This agency is responsible for decontamination and decommissioning of thousands of buildings. Electrokinetic extraction is one of the several innovative technologies which emerged in response to this initiative. This technique utilizes an electropotential gradient and the subsequent electrical transport mechanism to cause the controlled movement of ionics species, whereby the contaminants exit the recesses deep within the concrete. This report discusses the technology and use at the Oak Ridge k-25 plant.

  19. Radiation decontamination of spices

    International Nuclear Information System (INIS)

    Jan, M.; Sattar, A.; Ahmad, W.A.; Khan, I.

    1990-06-01

    In this report radiation decontamination was initiated to investigate the red pepper, which is widely consumed in all parts of Pakistan. The samples were collected from local market and prepared for gamma radiation at dose level of 0, 2.5, 5.0, 7.5, and 10.0 kGy. The measurement of total fungal count was carried out immediately after irradiation and the at two months storage interval. It was reported that radiation dose 10.0 kGy is suitable for complete decontamination of red pepper. (A.B.)

  20. Comparison and Evaluation of Various Tritium Decontamination Techniques and Processes

    International Nuclear Information System (INIS)

    Gentile, C.A.; Langish, S.W.; Skinner, C.H.; Ciebiera, L.P.

    2004-01-01

    In support of fusion energy development, various techniques and processes have been developed over the past two decades for the removal and decontamination of tritium from a variety of items, surfaces, and components. Tritium decontamination, by chemical, physical, mechanical, or a combination of these methods, is driven by two underlying motivational forces. The first of these motivational forces is safety. Safety is paramount to the established culture associated with fusion energy. The second of these motivational forces is cost. In all aspects, less tritium contamination equals lower operational and disposal costs. This paper will discuss and evaluate the various processes employed for tritium removal and decontamination

  1. Comparison and Evaluation of Various Tritium Decontamination Techniques and Processes

    International Nuclear Information System (INIS)

    Gentile, C.A.; Langish, S.W.; Skinner, C.H.; Ciebiera, L.P.

    2005-01-01

    In support of fusion energy development, various techniques and processes have been developed over the past two decades for the removal and decontamination of tritium from a variety of items, surfaces, and components. The motivational force for tritium decontamination by chemical, physical, mechanical, or a combination of these methods, is driven by two underlying forces. The first of these motivational forces is safety. Safety is paramount to the established culture associated with fusion energy. The second of these motivational forces is cost. In all aspects, less tritium contamination equals lower operational and disposal costs. This paper will discuss and evaluate the various processes employed for tritium removal and decontamination

  2. Psychosocial considerations for mass decontamination

    International Nuclear Information System (INIS)

    Lemyre, L.; Johnson, C.; Corneil, W.

    2010-01-01

    Mass exposure to explosions, infectious agents, food-borne illnesses, chemicals or radiological materials may require mass decontamination that have critical psychosocial implications for the public and for both traditional and non-traditional responders in terms of impact and of response. Five main issues are common to mass decontamination events: (i) perception, (ii) somatisation, (iii) media role and communication, (iv) information sharing, (v) behavioural guidance and (vi) organisational issues. Empirical evidence is drawn from a number of cases, including Chernobyl; Goiania, Brazil; the sarin gas attack in Tokyo; the anthrax attacks in the USA; Three Mile Island; and by features of the 2003 severe acute respiratory syndrome pandemic. In this paper, a common platform for mass casualty management is explored and suggestions for mass interventions are proposed across the complete event timeline, from pre-event threat and warning stages through to the impact and reconstruction phases. Implication for responders, health care and emergency infrastructure, public behaviour, screening processes, risk communication and media management are described. (authors)

  3. Application of Carrier Element-Free Co-precipitation Method for Ni(II), Cu(II) and Zn(II) Ions Determination in Water Samples Using Chrysin

    International Nuclear Information System (INIS)

    Layth Imad Abd Ali; Wan Aini Wan Ibrahim; Azli Sulaiman; Mohd Marsin Sanagi

    2015-01-01

    A co-precipitation method was developed to separate and pre-concentrate Ni(II), Cu(II) and Zn(II) ions using an organic co precipitant, chrysin without adding any carrier element termed as carrier element-free co-precipitation (CEFC). Analytes were determined using flame atomic absorption spectrometry (FAAS). The influence of analytical conditions, such as pH of the solution, quantity of co-precipitant, standing time, centrifugation rate and time, sample volume, and interference of concomitant ions were investigated over the recovery yields of the trace metals. The limit of detection, the limit of quantification and linearity range obtained from the FAAS measurements were found to be in the range of 0.64 to 0.86 μg L -1 , 2.13 to 2.86 μg L -1 and 0.9972 to 0.9989 for Ni(II), Cu(III) and Zn(II) ions, respectively. The precision of the method, evaluated as the relative standard deviation (RSD) obtained after analyzing a series of 10 replicates, was between 2.6 % to 3.9 % for the trace metal ions. The proposed procedure was applied and validated by analyzing river water reference material for trace metals (SLRS-5) and spiking trace metal ions in some water samples. The recoveries of the analyte metal ions were between 94.7-101.2 %. (author)

  4. Initial decontamination of the equipment decontamination room at the West Valley Demonstration Project. Topical report, September 1983-May 1985

    International Nuclear Information System (INIS)

    Meigs, R.A.

    1985-12-01

    The purpose of this report is to document the initial decontamination of the Equipment Decontamination Room (EDR). The effort spanned a two-year period and included packaging and removal of waste; grinding away contaminated concrete floors; pump-out and spraydown of an equipment soaking pit; washing and painting of walls, equipment, and floors; refurbishment of utilities and various pieces of equipment; and load tests of EDR and Chemical Process Cell (CPC) cranes. After decontamination, the EDR was converted into a waste handling area for the decommissioning of the CPC

  5. Evaluation of destructive methods for managing decontamination wastes

    International Nuclear Information System (INIS)

    Piciulo, P.L.; Adams, J.W.

    1986-01-01

    Results are discussed of a laboratory evaluation of destructive methods for processing chemical decontamination wastes. Incineration, acid digestion and wet-air oxidation are capable of degrading decontamination reagents and organic ion-exchange resins. The extent of destruction as a function of operating parameters was waste specific. The reagents used in the testing were: EDTA, oxalic acid, citric acid, picolinic acid and LND-101A

  6. Decontamination of process equipment using recyclable chelating solvent

    International Nuclear Information System (INIS)

    Jevec, J.; Lenore, C.; Ulbricht, S.

    1995-01-01

    The Department of Energy (DOE) is now faced with the task of meeting decontamination and decommissioning obligations at numerous facilities by the year 2019. Due to the tremendous volume of material involved, innovative decontamination technologies are being sought that can reduce the volumes of contaminated waste materials and secondary wastes requiring disposal. With sufficient decontamination, some of the material from DOE facilities could be released as scrap into the commercial sector for recycle, thereby reducing the volume of radioactive waste requiring disposal. Although recycling may initially prove to be more costly than current disposal practices, rapidly increasing disposal costs are expected to make recycling more and more cost effective. Additionally, recycling is now perceived as the ethical choice in a world where the consequences of replacing resources and throwing away reusable materials are impacting the well-being of the environment. Current approaches to the decontamination of metals most often involve one of four basic process types: (1) chemical, (2) manual and mechanical, (3) electrochemical, and (4) ultrasonic. open-quotes Hardclose quotes chemical decontamination solutions, capable of achieving decontamination factors (Df's) of 50 to 100, generally involve reagent concentrations in excess of 5%, tend to physically degrade the surface treated, and generate relatively large volumes of secondary waste. open-quotes Softclose quotes chemical decontamination solutions, capable of achieving Df's of 5 to 10, normally consist of reagents at concentrations of 0.1 to 1%, generally leave treated surfaces in a usable condition, and generate relatively low secondary waste volumes. Under contract to the Department of Energy, the Babcock ampersand Wilcox Company is developing a chemical decontamination process using chelating agents to remove uranium compounds and other actinide species from process equipment

  7. Recent developments in collaborative CBRN decontamination science : a retrospective

    Energy Technology Data Exchange (ETDEWEB)

    Yanofsky, N. [Defence Research and Development Canada, Ottawa, ON (Canada); Volchek, K.; Fingas, M. [Environment Canada, Ottawa, ON (Canada). Emergencies Science and Technology Division, Environmental Technology Centre, Science and Technology Branch; Filatov, B. [Research Inst. of Hygiene, Toxicology and Occupational Pathology, Volgograd (Russian Federation)

    2006-07-01

    The importance of addressing the risk of chemical, biological and radiological/nuclear (CBRN) attacks was discussed with particular reference to recent developments in Canadian-led decontamination studies as part of the remediation response to a terrorist attack. Research efforts have been supported by government programs such as the CBRN Research and Technology Initiative of Defence Research and Development Canada and the Global Partnership Program of the Department of Foreign Affairs. In 2005, Environment Canada and Defence Research and Development Canada co-organized an international workshop with the Research Institute of Health, Toxicology and Occupational Pathology of Volgograd, Russia. The workshop brought together researchers from Canada, Russia, United States, United Kingdom, Netherlands, Poland and Bulgaria, with the view to eventually develop longer term collaborations. The theme focused on membrane technology and its application in CBRN decontamination. This paper reviewed these collaborative and international research efforts and identified areas in need of future work, such as bioremediation and radio-nuclear remediation. It addressed issues supporting a collaborative international research agenda in decontamination science; membrane filtration as a feasible approach to decontamination waste treatment; and possible areas of CBRN collaboration. It was suggested that the key to successful decontamination requires the creation of computer systems for the initial identification of chemical substances; complete toxicological characterization of the most dangerous agents; regulatory safety standards; quantitative determination of chemical substances; antidotes for most chemical threat agents; universal decontamination agents; and, validation of criteria for decontaminating buildings. The question of who pays for decontamination, be it the private or public sector, was also discussed.

  8. Synthesis, Optical and Electrochemical Properties of Y2O3 Nanoparticles Prepared by Co-Precipitation Method.

    Science.gov (United States)

    Saravanan, Thulasingam; Raj, Srinivasan Gokul; Chandar, Nagamuthu Raja Krishna; Jayavel, Ramasamy

    2015-06-01

    Y2O3 nanoparticles were synthesized by co-precipitation route using yttrium nitrate hexahydrate and ammonium hydroxide as precursors. The prepared sample was calcined at 500 degrees C and subjected to various characterization studies like thermal analysis (TG/DTA), X-ray diffraction (XRD), transmission electron microscope (TEM), UV-visible (UV-Vis) and photoluminescence (PL) spectroscopy. The XRD pattern showed the cubic fluorite structure of Y2O3 without any impurity peaks, revealing high purity of the prepared sample. TEM images revealed that the calcined Y2O3 nanoparticles consist of spherical-like morphology with an average particle size of 12 nm. The absorption spectrum of calcined samples shows blue-shift compared to the as-prepared sample, which was further confirmed by PL studies. The possible formation mechanism of Y2O3 nanoparticles has been discussed based on the experimental results. Electrochemical behavior of Y2O3 nanoparticles was studied by cyclic voltammetry to assess their suitability for supercapacitor applications.

  9. Investigating the effect of Mn-doped CeO2 nanoparticles by co-precipitation method

    International Nuclear Information System (INIS)

    Prabaharan, D.D.M.; Sadaiyandi, K.; Mahendran, M.; Sagadevan, Suresh

    2018-01-01

    The paper exhibits a detailed study about the synthesis and characterization in analysis of structural, morphological, optical and electrical investigations of pure and Mn-doped Cerium oxide (CeO 2 ) nanoparticles which were synthesized by co-precipitation technique. Phase formation of the prepared sample was analyzed with powder X-ray diffraction (PXRD) examines, scanning electron microscopy (SEM) examination. The PXRD comes about affirmed partial crystallinity having cubic phases and the crystallite sizes of the pure and Mn-doped Cerium oxide (CeO 2 ) were estimated by utilizing Debye-Scherrer's formula and they were calculated to be 12 and 14 nm individually. SEM pictures revealed that the particles were profoundly accumulated and were of permeable nature. The optical properties of pure and Mn-doped CeO 2 were ascertained by using UV-visible absorption spectrum. The estimated band gap values for the pure and the Mn-doped CeO 2 nanoparticles were observed to be 2.7 and 2.6 eV, respectively, utilizing UV-Vis spectroscopy. At different frequencies and temperatures the dielectric properties of the Mn-doped Cerium oxide (CeO 2 ) nanoparticles, for example, the dielectric consistent, the dielectric loss and the AC conductivity, were studied. (orig.)

  10. Evaluation of the structure and microstructure of NixMg1-xO oxides obtained by co-precipitation

    International Nuclear Information System (INIS)

    Martinez L, G.; Kryshtab, T.; Hesiquio G, M.; Kryvko, A.

    2013-01-01

    Ni x Mg 1-x O oxides were prepared by thermal treatment at temperatures of 400, 600 and 800 C from a hydrotalcite-like precursor obtained by co-precipitation at constant ph. The oxides obtained were characterized by X-ray diffraction methods. From the obtained results we concluded that the oxides calcined at temperatures of 400, and 600 C are unstable that means that there exists the effect of memory and with a time they return to the precursor. Presence of Ni in Mg oxide provides stability of the compounds thermally treated at 800 C. In order to analyze the structure and microstructure, the reflections 111, 200 and 220 were used. The positions of the maxima of the diffraction peaks are shifted with respect to the simulated ones for Mg O and Ni O. This result reveals that in solid solutions studied compressive strains or vacation are present. The parameters of the microstructure (coherent domain size and micro deformations) were evaluated. The coherent domain size was found to be in the range of 8 - 10 nm and the presence of residual strains of micro deformation can be associated with the existence of extended defects. (Author)

  11. Preparation of LuAG Powders with Single Phase and Good Dispersion for Transparent Ceramics Using Co-Precipitation Method

    Science.gov (United States)

    Pan, Liangjie; Jiang, Benxue; Fan, Jintai; Yang, Qiuhong; Zhou, Chunlin; Zhang, Pande; Mao, Xiaojian; Zhang, Long

    2015-01-01

    The synthesis of pure and well dispersed lutetium aluminum garnet (LuAG) powder is crucial and important for the preparation of LuAG transparent ceramics. In this paper, high purity and well dispersed LuAG powders have been synthesized via co-precipitation method with lutetium nitrate and aluminum nitrate as raw materials. Ammonium hydrogen carbonate (AHC) was used as the precipitant. The influence of aging time, pH value, and dripping speed on the prepared LuAG powders were investigated. It showed that long aging duration (>15 h) with high terminal pH value (>7.80) resulted in segregation of rhombus Lu precipitate and Al precipitate. By decreasing the initial pH value or accelerating the dripping speed, rhombus Lu precipitate was eliminated and pure LuAG nano powders were synthesized. High quality LuAG transparent ceramics with transmission >75% at 1064 nm were fabricated using these well dispersed nano LuAG powders. PMID:28793510

  12. Preparation and characterization of polyol assisted ultrafine Cu–Ni–Mg–Ca mixed ferrite via co-precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Boobalan, T. [Park College of Engineering and Technology, Coimbatore (India); Pavithradevi, S. [Department of Physics, Government College of Technology, Coimbatore (India); Suriyanarayanan, N., E-mail: nsuri22@gmail.com [Department of Physics, PSG Polytechnic College, Coimbatore (India); Manivel Raja, M. [Defence Metallurgical Research Laboratory, Ministry of Defence, Govt. of India, Hyderabad (India); Ranjith Kumar, E., E-mail: ranjueaswar@gmail.com [Dr. NGP Institute of Technology, Coimbatore (India)

    2017-04-15

    Nanocrystalline spinel ferrite of composition Cu{sub 0.2}Ni{sub 0.2}Mg{sub 0.2}Ca{sub 0.4}Fe{sub 2}O{sub 4} is synthesized by wet hydroxyl co-precipitation method in ethylene glycol as chelating agent and sodium hydroxide as precipitator at pH 8. Ethylene glycol is utilized as the medium which serves as the dissolvable and in addition a complexing specialist. The synthesized particles are annealed at various temperatures. Thermogravimetric investigation affirms that at 280 °C ethylene glycol is dissipated totally and stable phase arrangement happens over 680 °C. FTIR spectra of as synthesized and annealed at 1050 °C recorded between 400 cm{sup −1} and 4000 cm{sup −1}. Structural characterizations of all the samples are carried out by X-ray diffraction (XRD) technique. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) affirm that the particles are spherical and cubic shape with the crystallite size of 12 nm to 32 nm. Magnetic measurements are performed utilizing vibrating sample magnetometer at room temperature. - Highlights: • Polyol improves purity of the spinel ferrite. • TG curves confirm the single phase ferrite is obtained above 680 °C. • Super paramagnetic behavior is seen at lower annealing temperature. • Soft ferromagnetic behavior is obtained at 1050 °C.

  13. Synthesis and characterization of La(Cr,Fe,Mn)O{sub 3} nanoparticles obtained by co-precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Fabian, F.A., E-mail: fernandafabianro@gmail.com [Universidade Federal de Sergipe, Campus Prof. Aluísio Campos, Departamento de Física, 49100-000 São Cristóvão, SE (Brazil); Pedra, P.P.; Filho, J.L.S. [Universidade Federal de Sergipe, Campus Prof. Aluísio Campos, Departamento de Física, 49100-000 São Cristóvão, SE (Brazil); Duque, J.G.S.; Meneses, C.T. [Universidade Federal de Sergipe, Campus Prof. Alberto Carvalho, Departamento de Física, 49500-000 Itabaiana, SE (Brazil)

    2015-04-01

    Magnetic and structural properties have been investigated in La(Cr,Fe,Mn)O{sub 3} nanoparticles obtained by co-precipitation method. The X-ray diffraction measurements allied to Rietveld method confirm the formation of LaCrO{sub 3}, LaFeO{sub 3} and LaMnO{sub 3} nanoparticles with crystal structure orthorhombic (Pbnm), orthorhombic (Pnma) and rhombohedral (R-3c), respectively. We also verified an decreasing in the average crystallite size from 73 to 26 nm, depending of the transition metal. The magnetic measurements reveal an antiferromagnetic behavior for the LaCrO{sub 3} sample with T{sub N}~289 K, and a weak ferromagnetic ordering for the LaMnO{sub 3} sample with T{sub c}~200 K. - Highlights: • La(Cr,Fe,Mn)O{sub 3} nanoparticles were synthesized by coprecipitation method. • XRD results confirm the formation single phase in the compounds studied. • Magnetic property in the La(Fe,Cr,Mn)O{sub 3} nanoparticles dependent on the TM. • La(Cr,Fe)O{sub 3} nanoparticles presented behavior antiferromagnetic and LaMnO{sub 3} ferromagnetic.

  14. Preparation of LuAG Powders with Single Phase and Good Dispersion for Transparent Ceramics Using Co-Precipitation Method

    Directory of Open Access Journals (Sweden)

    Liangjie Pan

    2015-08-01

    Full Text Available The synthesis of pure and well dispersed lutetium aluminum garnet (LuAG powder is crucial and important for the preparation of LuAG transparent ceramics. In this paper, high purity and well dispersed LuAG powders have been synthesized via co-precipitation method with lutetium nitrate and aluminum nitrate as raw materials. Ammonium hydrogen carbonate (AHC was used as the precipitant. The influence of aging time, pH value, and dripping speed on the prepared LuAG powders were investigated. It showed that long aging duration (>15 h with high terminal pH value (>7.80 resulted in segregation of rhombus Lu precipitate and Al precipitate. By decreasing the initial pH value or accelerating the dripping speed, rhombus Lu precipitate was eliminated and pure LuAG nano powders were synthesized. High quality LuAG transparent ceramics with transmission >75% at 1064 nm were fabricated using these well dispersed nano LuAG powders.

  15. One-step synthesis and characterizations of cerium oxide nanoparticles in an ambient temperature via Co-precipitation method

    Science.gov (United States)

    Pujar, Malatesh S.; Hunagund, Shirajahammad M.; Desai, Vani R.; Patil, Shivaprasadgouda; Sidarai, Ashok H.

    2018-04-01

    We report the simple Co-precipitation method for the synthesis of Cerium oxide (CeO2) nanoparticles (NPs) in an ambient temperature. We have taken the Cerium (III) nitrate hexahydrate (Ce(NO3)3.6H2O) and Sodium hydroxide (NaOH) as the precursors. The obtained NPs were analyzed using the UV-Vis spectrophotometer, Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The obtained results signify that UV-Vis spectrum exhibited a well-defined absorption peak at 274 nm and the estimated energy gap (Eg) is 4.05 eV. The FT-IR analysis provides the supporting evidence for the presence of bonding of O-H, nitrates, alcohols and O-Ce-O vibrations. The XRD result reveals that the synthesized CeO2 NPs was crystallite with cubic phase structure and the estimated average crystallite size of CeO2 NPs using Scherer's and W-H method was significantly different due to their assumptions. Further, it is purposed to study their photocatalytic biological activities.

  16. Structural, Optical, Morphological and Microbial Studies on SnO₂ Nanoparticles Prepared by Co-Precipitation Method.

    Science.gov (United States)

    Arularasu, M V; Anbarasu, M; Poovaragan, S; Sundaram, R; Kanimozhi, K; Magdalane, C Maria; Kaviyarasu, K; Thema, F T; Letsholathebe, D; Mola, Genene T; Maaza, M

    2018-05-01

    Nanoparticles of tin oxide (SnO2) powders were prepared by co-precipitation method at 500 °C, 700 °C and 900 °C temperature. The sintered SnO2 nanoparticles, structural, optical, magnetic, morphological properties and microbial activity have been studied. XRD studies reveals that sintered powder which exhibits tetragonal crystal structure and both crystallinity as well as crystal size increase with increase in temperature. The morphological studies reveal randomly arranged grains with compact nature grain size increases with sintering temperature. The compositional analyses of SnO2 nanoparticles have been studied using X-ray photoelectron spectroscopy analysis. The optical band gap values of SnO2 nanoparticles were calculated to be about 4.3 eV in the temperature 500 °C, comparing with that of the bulk SnO2 3.78 eV, by optical absorption measurement. Room temperature M-H curve for pure SnO2 nanoparticles exhibits ferromagnetic behaviour. The tin oxide nanoparticles are acted as potential candidate material for bacterial and fungal activity.

  17. Continuous precipitation of mineral products: influence of mixing conditions on the co-precipitation of cerium-zirconium mixed oxides

    International Nuclear Information System (INIS)

    Di Patrizio, Nicolas

    2015-01-01

    An automated experimental set-up with rapid mixers is used to study the influence of mixing conditions on the co-precipitation of cerium-zirconium mixed oxides. The intensity of mixing is controlled by the inlet flow rates of the reacting solutions. An engulfment model is used to estimate a mixing time from the measurement of a segregation index by the Villermaux-Dushman reaction system. Three geometries of Hartridge Roughton mixers are compared. Mixing performance is better when a separate mixing chamber upstream of a narrower outlet pipe is present. A better mixing decreases the maximal reducibility temperature of the material and increases the crystal strains of the particles calcined at 1100 C. This is probably due to a better homogenization of the particles content. The important incorporation of nitrates in the particle at the outlet of the mixers shows precipitation occurs while the mixing process is not finished. This experimental result was confirmed by numerical simulation and an estimation of sur-saturations during the mixing process. (author)

  18. Efficacy of scalp hair decontamination following exposure to vapours of sulphur mustard simulants 2-chloroethyl ethyl sulphide and methyl salicylate.

    Science.gov (United States)

    Spiandore, Marie; Piram, Anne; Lacoste, Alexandre; Prevost, Philippe; Maloni, Pascal; Torre, Franck; Asia, Laurence; Josse, Denis; Doumenq, Pierre

    2017-04-01

    Chemical warfare agents are an actual threat and victims' decontamination is a main concern when mass exposure occurs. Skin decontamination with current protocols has been widely documented, as well as surface decontamination. However, considering hair ability to trap chemicals in vapour phase, we investigated hair decontamination after exposure to sulphur mustard simulants methyl salicylate and 2-chloroethyl ethyl sulphide. Four decontamination protocols were tested on hair, combining showering and emergency decontamination (use of Fuller's earth or Reactive Skin Decontamination Lotion RSDL ® ). Both simulants were recovered from hair after treatment, but contents were significantly reduced (42-85% content allowance). Showering alone was the least efficient protocol. Concerning 2-chloroethyl ethyl sulphide, protocols did not display significant differences in decontamination efficacy. For MeS, use of emergency decontaminants significantly increased showering efficacy (10-20% rise), underlining their usefulness before thorough decontamination. Our results highlighted the need to extensively decontaminate hair after chemical exposure. Residual amounts after decontamination are challenging, as their release from hair could lead to health issues. Copyright © 2016. Published by Elsevier B.V.

  19. Decontamination processes for waste glass canisters

    International Nuclear Information System (INIS)

    Rankin, W.N.

    1982-01-01

    A Defense Waste Processing Facility (DWPF) is currently being designed to convert Savannah River Plant liquid, high-level radioactive waste into a solid form, such as borosilicate glass. To prevent the spread of radioactivity, the outside of the canisters of waste glass must have very low levels of smearable radioactive contamination before they are removed from the DWPF. Several techniques were considered for canister decontamination: high-pressure water spray, electropolishing, chemical dissolution, and abrasive blasting. An abrasive blasting technique using a glass frit slurry has been selected for use in the DWPF. No additional equipment is needed to process waste generated from decontamination. Frit used as the abrasive will be mixed with the waste and fed to the glass melter. In contrast, chemical and electrochemical techniques require more space in the DWPF, and produce large amounts of contaminated by-products, which are difficult to immobilize by vitrification

  20. [Decontamination of organophosphorus compounds: Towards new alternatives].

    Science.gov (United States)

    Poirier, L; Jacquet, P; Elias, M; Daudé, D; Chabrière, E

    2017-05-01

    Organophosphorus coumpounds (OP) are toxic chemicals mainly used for agricultural purpose such as insecticides and were also developed and used as warfare nerve agents. OP are inhibitors of acetylcholinesterase, a key enzyme involved in the regulation of the central nervous system. Chemical, physical and biological approaches have been considered to decontaminate OP. This review summarizes the current and emerging strategies that are investigated to tackle this issue with a special emphasis on enzymatic remediation methods. During the last decade, many studies have been dedicated to the development of biocatalysts for OP removal. Among these, recent reports have pointed out the promising enzyme SsoPox isolated from the archaea Sulfolobus solfataricus. Considering both its intrinsic stability and activity, this hyperthermostable enzyme is highly appealing for the decontamination of OP. Copyright © 2017 Académie Nationale de Pharmacie. All rights reserved.

  1. Pipe Decontamination Involving String-Foam Circulation

    International Nuclear Information System (INIS)

    Turchet, J.P.; Estienne, G.; Fournel, B.

    2002-01-01

    Foam applications number for nuclear decontamination purposes has recently increased. The major advantage of foam decontamination is the reduction of secondary liquid wastes volumes. Among foam applications, we focus on foam circulation in contaminated equipment. Dynamic properties of the system ensures an homogeneous and rapid effect of the foam bed-drifted chemical reagents present in the liquid phase. This paper describes a new approach of foam decontamination for pipes. It is based on an alternated air and foam injections. We called it 'string-foam circulation'. A further reduction of liquid wastes is achieved compared to continuous foam. Secondly, total pressure loss along the pipe is controlled by the total foam length in the pipe. It is thus possible to clean longer pipes keeping the pressure under atmospheric pressure value. This ensures the non dispersion of contamination. This study describes experimental results obtained with a neutral foam as well with an acid foam on a 130 m long loop. Finally, the decontamination of a 44 meters pipe is presented. (authors)

  2. Use of citric acid for large parts decontamination

    International Nuclear Information System (INIS)

    Holland, M.E.

    1979-01-01

    Laboratory and field studies have been performed to identify and evaluate chemical decontamination agents to replace ammonium carbonate, an environmentally unacceptable compound, in the decontamination facility for large process equipment at the Portsmouth Gaseous Diffusion Plant. Preliminary screening of over 40 possible decontamination agents on the basis of efficiency, availability, toxicity, cost, corrosiveness, and practicality indicated sodium carbonate and citric acid to be the most promising. Extensive laboratory studies were performed with these two reagents. Corrosion rates, decontamination factors, uranium recovery efficiencies, technetium ( 99 Tc)/ion exchange removal effects, and possible environmental impacts were determined or investigated. Favorable results were found in all areas. Detailed monitoring and analysis during two-week trial periods in which sodium carbonate and citric acid were used in the large parts decontamination facility resulted in similar evaluation and conclusions. Because it has cleaning properties not possessed by sodium carbonate, and because it eliminated several operational problems by incorporating two acidic decontamination reagents (citric and nitric acids) instead of one basic reagent (sodium or ammonium carbonate) and one acidic reagent (nitric acid), citric acid was selected for one-year field testing. On the basis of its excellent performance in the field tests, citric acid is recommended as a permanent replacement for ammonium carbonate in the decontamination facility for large process equipment

  3. Radionuclide co-precipitation

    International Nuclear Information System (INIS)

    Bruno, J.; Sandino, A.

    1987-12-01

    The thermodynamic and kinetic behaviour of the minor components of the spent fuel matrix has been theoretically and experimentally investigated. Two different situations have been studied: Part I, the near field scenario, where the release and migration of the minor components is dependent on the solubility behaviour of UO 2 (s); Part II, the far field, where the solubility and transport of the radionuclides is related to the major geochemical processes occurring. (orig.)

  4. A rapid and inexpensive bioassay to evaluate the decontamination of organophosphates.

    Science.gov (United States)

    Claborn, David M; Martin-Brown, Skylar A; Sagar, Sanjay Gupta; Durham, Paul

    2012-01-01

    An inexpensive and rapid bioassay using adult red flour beetles was developed for use in assessing the decontamination of environments containing organophosphates and related chemicals. A decontamination protocol was developed which demonstrated that 2 to 3 applications of 5% bleach solution were required to obtain nearly complete decontamination of malathion. The bioassay was also used to screen common household cleaners as potential decontaminating agents, but only 5% bleach was effective at improving survival of insects on steel plates treated with 25% malathion. A toxic degradation product (malaoxon) was detected using gas chromatography/mass spectrophotometry; this toxin affected the decontamination efficacy and resulted in continued toxicity to the beetles until subsequent decontaminations. The bioassay provides evidence to support the use of red flour beetles as a sensitive, less expensive method for determining safety levels of environments contaminated with malathion and other toxins, and may have application in the study of chemical warfare agents.

  5. An experimental study on decontamination by surface condition

    International Nuclear Information System (INIS)

    Lee, Young Hae

    1974-01-01

    Surface decontamination is one of the very important problem to be completely solved in the isotope laboratory where there is always the possibility of radioactive contamination, i.e., on the floors, walls, working tables and benches etc., Isotope laboratories require surface covering of material which can be easily and effectively decontaminated. These experiment were done to find an effective decontamination procedure for kind of surfaces which usually are found in radioisotope laboratories and the best type of surface material, that is, one which is easily decontaminated from the point of view of radiation health and safely. This study is presented to guide radioisotope laboratories in Korea which may need to renovate existing unsafe facilities. In some contaminated facilities entirely new installations may be required. Twelve types of surface material are used for study in this experiment. These include 10 cm square of stainless steel, aluminum, ceramic and mosaic tiles, glass, acrylic, formica board, asphalt tile and coated wood with 4 kinds of paints. Stepwise decontamination was performed with various decontamination procedures following a spill of I 1 31 on the center of the surface material being tested. Twelve different decontamination procedures were tested. These included wet wiping with water and detergent, or dry wiping, or removing with gummed paper. Additional chemical procedures used 10% solution of hydrochloric acid, or surface acid, or ammonium citrate, or potassium iodide, or acetone or carbon tetrachloride. The final testing method was abrasion of the test surfaces. Brief analysis of experimental results on the decontaminability on the tested surface showed: 1. Metallic surfaces such as stainless steel or aluminum, or glass, or a piece of ceramic tile or acrylic are recommended as the surface materials for isotope laboratories because these are easily decontaminated by wet wiping only. 2. Formica board, asphalt tile and wood are not easily

  6. Some aspects of radioactive contamination and decontamination of the Chernobyl' NPP accident zone territory

    International Nuclear Information System (INIS)

    Samojlenko, Yu.N.; Nad''yarnykh, G.V.; Teplitskij, A.L.; Shilin, S.A.

    1989-01-01

    Data are presented on the radioactive contamination of the 30-km zone, on the radionuclide (RN) distribution in soils and on the RN migration in grounds. During 1986-1988 were tested over 20 techniques for territory decontamination and were found out the most optimal ones. The first stage of decontamination was removal of an upper contaminated soil layer. The second stage was prolonged chemical fixation of dusting decontaminated soil areas. 3 tabs

  7. A decontamination technique for decommissioning waste

    International Nuclear Information System (INIS)

    Heki, H.; Hosaka, K.; Kuribayashi, N.; Ishikura, T.

    1993-01-01

    A large amount of radioactive metallic waste is generated from decommissioned commercial nuclear reactors. It is necessary from the point of environmental protection and resource utilization to decontaminate the contaminated metallic waste. A decommissioning waste processing system has been previously proposed considering such decommissioning waste characteristics as its large quantity, large radioactivity range, and various shapes and materials. The decontamination process in this system was carried out by abrasive blasting as pretreatment, electrochemical decontamination as the main process, and ultrasonic cleaning in water as post-treatment. For electrochemical decontamination, electrolytic decontamination for simple shaped waste and REDOX decontamination for complicated shaped waste were used as effective decontamination processing. This time, various kinds of actual radioactive contaminated samples were taken from operating power plants to simulate the decontamination of decommissioning waste. After analyzing the composition, morphogenesis and surface observation, electrolytic decontamination, REDOX decontamination, and ultrasonic cleaning experiments were carried out by using these samples. As a result, all the samples were decontaminated below the assumed exemption level(=4 x 10 -2 Bq/g). A maximum decontamination factor of over 104 was obtained by both electrolytic and REDOX decontamination. The stainless steel sample was easy to decontaminate in both electrochemical decontaminations because of its thin oxidized layer. The ultrasonic cleaning process after electrochemical decontamination worked effectively for removing adhesive sludge and the contaminated liquid. It has been concluded from the results mentioned above that electrolytic decontamination and REDOX decontamination are effective decontamination process for decontaminating decommissioning waste

  8. Synthesis and magnetic properties of (Eu–Ni) substituted Y-type hexaferrite by surfactant assisted co-precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Irshad, E-mail: irshadalibzu@gmail.com [Department of Physics, BahauddinZakariya University, Multan, P.O# 60800 (Pakistan); Islam, M.U. [Department of Physics, BahauddinZakariya University, Multan, P.O# 60800 (Pakistan); Sadiq, Imran [Department of Physics, BahauddinZakariya University, Multan, P.O# 60800 (Pakistan); Centre of Excellence in Solid State Physics, University of The Punjab, Lahore (Pakistan); Karamat, Nazia [Institute of Chemical Science, Bahauddin Zakariya University, Multan 60800 (Pakistan); Iftikhar, Aisha [Department of Physics, BahauddinZakariya University, Multan, P.O# 60800 (Pakistan); Khan, M. Azhar [Department of Physics, Islamia University of Bahawalpur, 63100 Pakistan (Pakistan); Shah, Afzal [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Athar, Muhammad [Institute of Chemical Science, Bahauddin Zakariya University, Multan 60800 (Pakistan); Shakir, Imran [Sustainable Energy Technologies (SET) Center, College of Engineering, King Saud University (Saudi Arabia); Ashiq, Muhammad Naeem, E-mail: naeemashiqqau@yahoo.com [Institute of Chemical Science, Bahauddin Zakariya University, Multan 60800 (Pakistan)

    2015-07-01

    A series of (Eu–Ni) substituted Y-type hexaferrite with composition Sr{sub 2}Co{sub (2−x)}Ni{sub x}Eu{sub y}Fe{sub (12−y)}O{sub 22} (x=0.0–1, Y=0.0–0.1) were prepared by the surfactant assisted co-precipitation method. The present samples were sintered at 1050 °C for 8 h. The shape of the particles is plate-like which is very advantageous for various applications and the grain size varies from 73 to 269 nm. The values of saturation magnetization (M{sub s}), remanent magnetization (M{sub r}) and magnetic moment (n{sub B}) were found to decrease which are attributed to the weakening of super exchange interactions. The values of in-plane Squareness ratios (M{sub r}/M{sub s}) ranging from 0.41 to 0.65 whereas in case of out of plane measurement it varies from 0.30 to 0.62.The investigated samples can be used in perpendicular recording media (PRM) due to high value of coercivity 2300 Oe which is analogous to the those of M-type and W-type hard magnetic. - Highlights: • The present samples sintered at 1050 °C for 8 h. • The grain size varies from 73 to 269 nm. • The magnetic moment varies from 15.27 to 6.07. • The shape of grains is plate like for microwave devices. • The present samples can be used in PRM due to high value of coercivity i.e. 2300 Oe.

  9. Synthesis of composite nanoparticles using co-precipitation of a magnetic iron-oxide shell onto core nanoparticles

    International Nuclear Information System (INIS)

    Primc, Darinka; Belec, Blaž; Makovec, Darko

    2016-01-01

    Composite nanoparticles can be synthesized by coating a shell made of one material onto core nanoparticles made of another material. Here we report on a novel method for coating a magnetic iron oxide onto the surface of core nanoparticles in an aqueous suspension. The method is based on the heterogeneous nucleation of an initial product of Fe"3"+/Fe"2"+ co-precipitation on the core nanoparticles. The close control of the supersaturation of the precipitating species required for an exclusively heterogeneous nucleation and the growth of the shell were achieved by immobilizing the reactive Fe"3"+ ions in a nitrate complex with urea ([Fe((CO(NH_2)_2)_6](NO_3)_3) and by using solid Mg(OH)_2 as the precipitating reagent. The slow thermal decomposition of the complex at 60 °C homogeneously releases the reactive Fe"3"+ ions into the suspension of the core nanoparticles. The key stage of the process is the thermal hydrolysis of the released Fe"3"+ ions prior to the addition of Mg(OH)_2. The thermal hydrolysis results in the formation of γ-FeOOH, exclusively at the surfaces of the core nanoparticles. After the addition of the solid hydroxide Mg(OH)_2, the pH increases and at pH ~ 5.7 the Fe"2"+ precipitates and reacts with the γ-FeOOH to form magnetic iron oxide with a spinel structure (spinel ferrite) at the surfaces of the core nanoparticles. The proposed low-temperature method for the synthesis of composite nanoparticles is capable of forming well-defined interfaces between the two components, important for the coupling of the different properties. The procedure is environmentally friendly, inexpensive, and appropriate for scaling up to mass production.Graphical abstract

  10. Soil decontamination with Extraksol

    International Nuclear Information System (INIS)

    Paquin, J.; Mourato, D.

    1989-01-01

    The Extraksol process is a mobile decontamination technology which treats unconsolidated materials by solvent extraction. Treatment with Extraksol involves material washing, drying and solvent regeneration. Contaminant removal is achieved through desorption/dissolution mechanisms. The treated material is dry and acceptable to be reinstalled in its original location. The process provides a fast, efficient and versatile alternative for decontamination of soil and sludge. The organic contaminants extracted from the matrix are transferred to the extraction fluids. These are thereafter concentrated in the residues of distillation after solvent regeneration. Removal and concentration of the contaminants ensures an important waste volume reduction. This paper presents the process is operational principles and the steps involved in Extraksol's development with results of the pilot tests and full-scale demonstrations

  11. Decontamination for free release

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, K A; Elder, G R [Bradtec Ltd., Bristol (United Kingdom)

    1997-02-01

    Many countries are seeking to treat radioactive waste in ways which meet the local regulatory requirements, but yet are cost effective when all contributing factors are assessed. In some countries there are increasing amounts of waste, arising from nuclear plant decommissioning, which are categorized as low level waste: however with suitable treatment a large part of such wastes might become beyond regulatory control and be able to be released as non-radioactive. The benefits and disadvantages of additional treatment before disposal need to be considered. Several processes falling within the overall description of decontamination for free release have been developed and applied, and these are outlined. In one instance the process seeks to take advantage of techniques and equipment used for decontaminating water reactor circuits intermittently through reactor life. (author). 9 refs, 1 fig., 3 tabs.

  12. Sunflowers to decontaminate water

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    Sunflowers offer a new method of decontamination. 55 kilograms (dry weight) of sunflowers are able to decontaminate all the cesium 137 and the strontium 90 polluting a pond situated at one kilometer from Tchernobyl. These flowers are able to decrease 95% in 24 hours the uranium concentration in the american site of Ashtabula in Ohio getting this water from 350 parts by milliards to less than 5 parts by milliards. The radioactivity should stocked in the roots at concentrations 5 000 to 10 000 times higher than water concentration. The cost is cheaper than micro filtration and precipitation (2-6 dollars for 4 000 liters of water against 80 dollars for others technologies). when sunflowers are radioactive they can be reduced in dust and vitrified and stocked as solid radioactive wastes. (N.C.)

  13. OPO fabric decontamination

    International Nuclear Information System (INIS)

    Severa, J.; Bar, J.; Grujbar, V.

    1978-01-01

    Samples of five polypropylene-based man-made fabrics were studied with regard to the degree of contamination and possibilities of decontamination in order to assess their suitability as material for protective clothing in the nuclear industry. The contamination degree of the fabrics in an aqueous solution of a fission product mixture was found to be low. Soaking in a mixture of the Sapon detergent and sodium hexametaphosphate at a concentration of both materials of 1 g/l with subsequent washing in a solution of the Zenit detergent at a concentration of 3 g/l was suggested as the most suitable decontamination procedure. It reduces the initial contamination by almost 99%. (Z.M.)

  14. Volume reduction and material recirculation by freon decontamination

    International Nuclear Information System (INIS)

    Berners, O.; Buhmann, D.; Yamashita, Y.; Yoshiaki, M.

    1989-01-01

    This paper discusses the use of freon in a large variety of decontamination in the nuclear and non-nuclear fields. As far as the contamination is loose or smerable, surfaces of nearly all materials can be decontaminated. Freon is electrically non-conductive, chemically neutral and has a low surface tension. So it is capable of creeping under the contaminant and loosening or dissolving it. Used freon can be collected, cleaned and recirculated. Its cleaning can be done easily by evaporation at its lower vapor point of about 48 degrees C (104 degrees F). Good decontamination results could be achieved, expensive materials, tools and equipment could be recirculated. Big volumes of materials could get separated from their contaminants, which is the real radioactive waste. Freon decontamination is an effective, overall economical and approved technology to volume reduction and material recirculation

  15. Steam Generator Group Project. Task 6. Channel head decontamination

    International Nuclear Information System (INIS)

    Allen, R.P.; Clark, R.L.; Reece, W.D.

    1984-08-01

    The Steam Generator Group Project utilizes a retired-from-service pressurized-water-reactor steam generator as a test bed and source of specimens for research. An important preparatory step to primary side research activities was reduction of the radiation field in the steam generator channel head. This task report describes the channel head decontamination activities. Though not a programmatic research objective it was judged beneficial to explore the use of dilute reagent chemical decontamination techniques. These techniques presented potential for reduced personnel exposure and reduced secondary radwaste generation, over currently used abrasive blasting techniques. Two techniques with extensive laboratory research and vendors prepared to offer commercial application were tested, one on either side of the channel head. As indicated in the report, both techniques accomplished similar decontamination objectives. Neither technique damaged the generator channel head or tubing materials, as applied. This report provides details of the decontamination operations. Application system and operating conditions are described

  16. System decontamination as a tool to control radiation fields

    Energy Technology Data Exchange (ETDEWEB)

    Riess, R.; Bertholdt, H.O. [Siemens Power Generation Group, Erlangen (Germany)

    1995-03-01

    Since chemical decontamination of the Reactor Coolant Systems (RCS) and subsystems has the highest potential to reduce radiation fields in a short term this technology has gained an increasing importance. The available decontamination process at Siemens, i.e., the CORD processes, will be described. It is characterized by using permanganic acid for preoxidation and diluted organic acid for the decontamination step. It is a regenerative process resulting in very low waste volumes. This technology has been used frequently in Europe and Japan in both RCS and subsystems. An overview will be given i.e. on the 1993 applications. This overview will include plant, scope, date of performance, system volume specal features of the process removed activities, decon factor time, waste volumes, and personnel dose during decontamination. This overview will be followed by an outlook on future developments in this area.

  17. Sensitive Equipment Decontamination

    Science.gov (United States)

    2017-10-01

    a ceramic-like material Polonium - 210 Metallic foil Radium-226 Radium bromide or radium chloride Strontium-90 Metallic strontium, strontium...extremely toxic toxins. 3.1.1.5 Routes of Infection Pathogenic microorganisms are transferred to human beings largely via air and food (including...regularly in the pharmaceutical industry to decontaminate manufacturing clean rooms. It is also used to sterilize packages used to store foods . It has

  18. Decommissioning and decontamination

    International Nuclear Information System (INIS)

    Dadoumont, J.; Cantrel, E.; Valenduc, P.; Noynaert, L.

    2009-01-01

    The SCK-CEN has built a large know-how in decommissioning and decontamination, thanks to its BR3 decommissioning project. In 2007, the decommissioning activities at BR3 have been continued according to the strategy. This article discusses main realisations the following domains: decommissioning of the neutron shield tank and installation of new ventilation for the controlled area, dismantling of the former one and characterization of the stack

  19. Local strategies for decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Hubert, P [Institut de Protection et de Surete Nucleaire, Fontenay-aux-Roses cedex (France); Ramzaev, V [Branch of Institute of Radiation Hygiene, Novozybkov, Bryansk region (Russian Federation); Antsypov, G [Chernnobyl State Committee of the Republic of Belarus, Minsk (Belarus); Sobotovich, E [Institute of Geochemistry, Mineralogy and Ore formation, Kiev (Ukraine); Anisimova, L [EMERCOM, Moscow (Russian Federation)

    1996-07-01

    The efficiencies of a great number of techniques for decontamination or dose reduction in contaminated areas have been investigated by several teams of E.C. and CIS scientists (ECP4 project). Modelling, laboratory and field experiments, t and return from experience allowed to assess radiological efficiencies (e.g. 'decontamination factor') and requirements for the operation of numerous practical solutions. Then, those data were supplemented with data on cost and waste generation in order to elaborate all the information for the optimization of decontamination strategies. Results will be presented for about 70 techniques. However, a technique cannot be compared to another from a generic point of view. Rather it is designed for a specific target and the best technology depends on the objectives. It has been decided to implement decision analyses on case studies, and the local conditions and objectives have been investigated. Individual doses ranged from 1 to 5 mSv, with contrasted contributions of internal and external doses. The desire to restore a normal activity in a partially depopulated settlement, and concerns about the recent increase in internal doses were typical incentives for action. The decision aiding analysis illustrated that actions can be usually recommended. Results are outlined here.

  20. Local strategies for decontamination

    International Nuclear Information System (INIS)

    Hubert, P.; Ramzaev, V.; Antsypov, G.; Sobotovich, E.; Anisimova, L.

    1996-01-01

    The efficiencies of a great number of techniques for decontamination or dose reduction in contaminated areas have been investigated by several teams of E.C. and CIS scientists (ECP4 project). Modelling, laboratory and field experiments, t and return from experience allowed to assess radiological efficiencies (e.g. 'decontamination factor') and requirements for the operation of numerous practical solutions. Then, those data were supplemented with data on cost and waste generation in order to elaborate all the information for the optimization of decontamination strategies. Results will be presented for about 70 techniques. However, a technique cannot be compared to another from a generic point of view. Rather it is designed for a specific target and the best technology depends on the objectives. It has been decided to implement decision analyses on case studies, and the local conditions and objectives have been investigated. Individual doses ranged from 1 to 5 mSv, with contrasted contributions of internal and external doses. The desire to restore a normal activity in a partially depopulated settlement, and concerns about the recent increase in internal doses were typical incentives for action. The decision aiding analysis illustrated that actions can be usually recommended. Results are outlined here