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Sample records for thorium processing plant

  1. Mortality among female workers at a thorium-processing plant

    International Nuclear Information System (INIS)

    Liu, Zhiyuan; Lee, Tze-San.

    1994-01-01

    The mortality patterns among a cohort of 677 female workers at a thorium-processing plant are reported for the period from 1940 to 1982. Of the 677 women, 165 were reported dead; 459 were still alive; and 53 (7.8%) were lost to follow-up. The standardized mortality ratios from all causes (0.74), all cancers (0.53), and circulatory diseases (0.66) were significantly below those for the general US population. In this cohort, 5 deaths due to lung cancer and 1 death from leukemia were observed, with 4.53 and 1.69 deaths expected, respectively. No deaths from cancer of the liver, pancreas, or bone were observed. Poisson regression analysis was used for an internal comparison within the cohort. The results of the Poisson regression analysis showed no significant effect on mortality rates of all causes and cancers from the study factors, including job classification, duration of employment, and time since first employment

  2. Preliminary design needs for pilot plant of Monazite processing into Thorium Oxide (ThO_2)

    International Nuclear Information System (INIS)

    Hafni Lissa Nuri; Prayitno; Abdul Jami; M-Pancoko

    2014-01-01

    Data and information collection aimed in order to meet the needs of the initial design for pilot plant of monazite processing into thorium oxide (ThO_2). The content of thorium in monazite is high in Indonesia between 2.9 to 4.1% and relatively abundant in Bangka Belitung Islands. Thorium can be used as fuel because of its potential is more abundant instead of uranium. Plant of thorium oxide commercially from monazite established starting from pilot uranium. Plant of thorium oxide commercially from monazite established starting from pilot plant in order to test laboratory data. Pilot plant design started from initial design, basic design, detailed design, procurement and construction. Preliminary design needs includes data feed and products, a block diagram of the process, a description of the process, the determination of process conditions and type of major appliance has been conducted. (author)

  3. Process specifications and standards for the 1970 thorium campaign in the Purex Plant

    International Nuclear Information System (INIS)

    Van der Cook, R.E.; Ritter, G.L.

    1970-01-01

    The process specifications and standards for thorium processing operations in the Purex Plant are presented. These specifications represent currently known limits within which plant processing conditions must be maintained to meet defined product requirements safely and with minimum effect on equipment service life. These specifications cover the general areas of feed, essential materials, and chemical hazards

  4. Mortality among male workers at a thorium-processing plant

    International Nuclear Information System (INIS)

    Polednak, A.P.; Stehney, A.F.; Lucas, H.F. Jr.

    1981-01-01

    Mortality is described in a cohort of 3039 men who were employed between 1940 and 1973 at a company involved in the production of thorium and rare earth chemicals from monazite sand. The standardized mortality ratio (SMR) for all causes was 1.05. SMR's were high for cancers of the lung (1,44), rectum (1.90), and pancreas (2.01), and for motor vehicle accidents (1.64). A subgroup of 592 men who worked for one year or longer in selected jobs (laborer, operator, maintenance) was followed up more intensively. SMR's were high for both lung cancer (1.62; 95% CL = 0.78 and 2.98) and pancreatic cancer (4.01; 95% CL = 1.30 and 9.34). The higher proportion of smokers in this subgroup relative to US males could have explained at least part of the excess mortality from lung cancer. Continued follow-up of the cohort in morbidity and mortality studies is needed to evaluate further these possible long-term effects of exposure to radioactivity and chemicals in the thorium extraction process

  5. Recovering of thorium contained in wastes from Thorium Purification Plant

    International Nuclear Information System (INIS)

    Brandao Filho, D.; Hespanhol, E.C.B.; Baba, S.; Miranda, L.E.T.; Araujo, J.A. de.

    1992-08-01

    A study has been developed in order to establish a chemical process for recovering thorium from wastes produced at the Thorium Purification Plant of the Instituto de Pesquisas Energeticas e Nucleares. The recovery of thorium in this process will be made by means of solvent extraction technique. Solutions of TBP/Varsol were employed as extracting agent during the runs. The influence of thorium concentration in the solution, aqueous phase acidity, volume ratio of the phases, percentage of TBP/Varsol and the contact time of the phases on the extraction of thorium and lanthanides was determined. (author)

  6. Recovery of protactinium-231 and thorium-230 from cotter concentrate: pilot plant operatins and process development

    International Nuclear Information System (INIS)

    Hertz, M.R.; Figgins, P.E.; Deal, W.R.

    1983-01-01

    The equipment and methods used to recover and purify 339 g of thorium-230 and 890 mg of protactinium-231 from 22 of the 1251 drums of Cotter Concentrate are described. The process developed was (1) dissolution at 100 0 C in concentrated nitric acid and dilution to 2 to 3 molar acid, (2) filtration to remove undissolved solids (mostly silica filter aid), (3) extraction of uranium with di-sec-butyl-phenyl phophonate (DSBPP) in carbon tetrachloride, (4) extraction of both thorium and protactinium with tri-n-octylphosphine oxide (TOPO) in carbon tetrachloride followed by selective stripping of the thorium with dilute of sulfuric acid, (5) thorium purification using oxalic acid, (6) stripping protactinium from the TOPO with oxalic acid, and (7) protactinium purification through a sequence of steps. The development of the separation procedures, the design of the pilot plant, and the operating procedures are described in detail. Analytical procedures are given in an appendix. 8 figures, 4 tables

  7. Thorium base fuels reprocessing at the L.P.R. (Radiochemical Processes Laboratory) experimental plant

    International Nuclear Information System (INIS)

    Almagro, J.C.; Dupetit, G.A.; Deandreis, R.A.

    1987-01-01

    The availability of the LPR (Radiochemical Processes Laboratory) plant offers the possibility to demonstrate and create the necessary technological basis for thorium fuels reprocessing. To this purpose, the solvents extraction technique is used, employing TBP (at 30%) as solvent. The process is named THOREX, a one-cycle acid, which permits an adequate separation of Th 232 and U 233 components and fission products. For thorium oxide elements dissolution, the 'chopp-leach' process (installed at LPR) is used, employing a NO 3 H 13N, 0.05M FH and 0.1M Al (NO 3 ) 3 , as solvent. To adapt the pilot plant to the flow-sheet requirements proposed, minor modifications must be carried out in the interconnection of the existing decanting mixers. The input of the plant has been calculated by Origin Code modified for irradiations in reactors of the HWR type. (Author)

  8. Radiological significance of thorium processing in manufacturing

    International Nuclear Information System (INIS)

    Davis, M.W.

    1985-01-01

    The study of thorium processing in manufacturing comprised monitoring programs at a plant where thorium dioxide was in use and another where the use of thorium nitrate had been discontinued. The measurements of the solubility in simulated lung fluid proved that both materials belonged in the Y Class with dissolution half-times greater than 500 days. Bioassay measurements of 20 subjects from both facilities proved that in vitro monitoring methods, urine, feces, hair and nails analysis were not sufficient indicators of thorium uptake. In vivo monitoring by phoswich and large sodium iodide detectors were proven to be good methods of determining thorium lung burdens. The thoron in breath technique was shown to have a lower limit of sensitivity than lung counting, however, due to lack of information regarding the thoron escape rate from the thorium particles in the lungs the method is not as accurate as lung counting. Two subjects at the thorium dioxide facility had lung burdens of 21+- 16 Bq and 29+- 24 Bq Th 232 and one at the thorium nitrate facility had a lung burden of 37+- 13 Bq. Improvements in the procedures and use of a glove box were among the recommendations to reduce the inhalation of thorium by workers at the thorium dioxide facility. Decontamination of several rooms at the thorium nitrate facility and sealing of the walls and floors were recommended in order to reduce the escape of thoron gas into the room air. The risk to non Atomic Radiation Workers was primarily due to thoron daughters in air while gamma radiation and thorium in air were less important. Conversely, at the thorium dioxide facility the inhalation of thorium in air was the most significant exposure pathway

  9. Environmental and radiological aspects of thorium processing in India

    International Nuclear Information System (INIS)

    Rudran, Kamala; Paul, A.C.; Pillai, P.M.B.; Saha, S.C.; Vidyasagar, D.; Sawant, Pramilla D.

    1997-01-01

    India has an active programme for using thorium as third stage self- sustaining nuclear fuel. A significant amount of thorium is also used in the gas mantle industry. The presently estimated monazite deposits amounting to five million tonnes are distributed in the beach sands of south western and eastern coasts and some areas in Andhra Pradesh. The sands are processed for recovery of rare earth minerals and thorium. The mineral processing and thorium separation involves hazards to workers from exposure to radiation, radioactive and silica bearing dusts as well as from conventional chemicals used in the processing. Releases of wastes from the plants may necessitate environmental surveillance. The present paper reviews the hazards envisaged, steps taken to mitigate such hazards and achievements in this regard in the thorium industry in India. (author)

  10. Assessment of thorium and thoron decay products in air - thorium plant

    International Nuclear Information System (INIS)

    Dhandayutham, R.; Gohel, C.O.; Shetty, P.N.; Savant, P.B.; Rao, D.V.V.

    1977-01-01

    For the evaluation of radiation dose to the lungs in a thorium plant, it is necessary to estimate the concentration of thorium, thoron and its daughter products in air. Methods employed in estimating thorium and its decay products and 'working level' are presented. (M.G.B.)

  11. Recovering of thorium contained in wastes from Thorium Purification Plant; Reaproveitamento do torio contido em residuos provenientes da Usina de Purificacao do Torio

    Energy Technology Data Exchange (ETDEWEB)

    Brandao Filho, D; Hespanhol, E C.B.; Baba, S; Miranda, L E.T.; Araujo, J.A. de

    1992-08-01

    A study has been developed in order to establish a chemical process for recovering thorium from wastes produced at the Thorium Purification Plant of the Instituto de Pesquisas Energeticas e Nucleares. The recovery of thorium in this process will be made by means of solvent extraction technique. Solutions of TBP/Varsol were employed as extracting agent during the runs. The influence of thorium concentration in the solution, aqueous phase acidity, volume ratio of the phases, percentage of TBP/Varsol and the contact time of the phases on the extraction of thorium and lanthanides was determined. (author).

  12. Experiences in running solvent extraction plant for thorium compounds [Paper No. : V-5

    International Nuclear Information System (INIS)

    Gopalkrishnan, C.R.; Bhatt, J.P.; Kelkar, G.K.

    1979-01-01

    Indian Rare Earths Ltd. operates a Plant using thorium concentrates as raw material, employing hydrocarbonate route, for the manufacture of thorium compounds. A small demonstration solvent extraction plant designed by the Chemical Engineering Division, B.A.R.C. is also being operated for the same purpose using a partly purified thorium hydrocarbonate as raw material. In the solvent extraction process, separation of pure thorium is done in mixer settlers using 40% mixture of tri-butyl phosphate in kerosene. Though a comparatively purer raw material of hydrocarbonate than thorium concentrate is used, heavy muck formation is encountered in the extraction stage. Production of nuclear grade thorium oxide has been successful so far as quality is concerned. The quality of thorium nitrate suffers in the yellow colouration and high phosphate content, the former being only partly controlled through the use of pretreated kerosene. When a larger solvent extraction plant is to be designed to use thorium concentrates as raw material, some of the problems encountered will be considered. (author)

  13. PLUTONIUM PURIFICATION PROCESS EMPLOYING THORIUM PYROPHOSPHATE CARRIER

    Science.gov (United States)

    King, E.L.

    1959-04-28

    The separation and purification of plutonium from the radioactive elements of lower atomic weight is described. The process of this invention comprises forming a 0.5 to 2 M aqueous acidffc solution containing plutonium fons in the tetravalent state and elements with which it is normally contaminated in neutron irradiated uranium, treating the solution with a double thorium compound and a soluble pyrophosphate compound (Na/sub 4/P/sub 2/O/sub 7/) whereby a carrier precipitate of thorium A method is presented of reducing neptunium and - trite is advantageous since it destroys any hydrazine f so that they can be removed from solutions in which they are contained is described. In the carrier precipitation process for the separation of plutonium from uranium and fission products including zirconium and columbium, the precipitated blsmuth phosphate carries some zirconium, columbium, and uranium impurities. According to the invention such impurities can be complexed and removed by dissolving the contaminated carrier precipitate in 10M nitric acid, followed by addition of fluosilicic acid to about 1M, diluting the solution to about 1M in nitric acid, and then adding phosphoric acid to re-precipitate bismuth phosphate carrying plutonium.

  14. Thermodynamics of dehydration process of uranyl nitrate pentahydrate of thorium

    International Nuclear Information System (INIS)

    Khamidov, F.A.; Mirsaidov, I.U.; Nazarov, K.M.; Nasriddinov, S.K.; Badalov, A.B.

    2010-01-01

    Present article is devoted to thermodynamics of dehydration process of uranyl nitrate pentahydrate of thorium. The results of researches of dehydration process of uranyl nitrate pentahydrate of thorium Th(NO_3)_4·5H_2O were considered. The researches were carried out by means of tensimeter method with membrane zero-manometer under equilibrium conditions and at 300-450 K temperature ranges. The thermodynamic characteristics of dehydration process of initial crystalline hydrate was defined.

  15. Composition of hydroponic medium affects thorium uptake by tobacco plants

    Czech Academy of Sciences Publication Activity Database

    Soudek, Petr; Kufner, Daniel; Petrová, Šárka; Mihaljevič, M.; Vaněk, Tomáš

    2013-01-01

    Roč. 92, č. 9 (2013), s. 1090-1098 ISSN 0045-6535 R&D Projects: GA MŠk LH12162; GA MŠk(CZ) LD13029; GA MPO FR-TI3/778 Institutional research plan: CEZ:AV0Z50380511 Keywords : Thorium * Plant uptake * Polyamines Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 3.499, year: 2013

  16. Uranium and Thorium in zircon sands processed in Northeastern Brazil

    International Nuclear Information System (INIS)

    Hazin, Clovis A.; Farias, Emerson E. G. de

    2008-01-01

    Zircon the main mineral of zirconium is a silicate mineral product (ZrSiO 4 ) obtained from beach sand deposits, along with other minerals such as kyanite, ilmenite, and rutile. All zircons contain some radioactive impurities due to the presence of uranium, thorium and their respective decay products in the crystalline structure of zircon, as well as potassium-40. Uranium and thorium substitute Zr 4+ in the mineral through an internal process called isomorphous replacement of zirconium. For this study, samples were collected both from a mineral sand processing plant located in the coastal region of Northeastern brazil and from the beach sands used in the process. The aim of this study was to assess the 238 U, 232 Th and 40 K contents in the beach sands and in the mineral products extracted from the sands in that facility, with special emphasis on zircon. Measurements were performed through gamma spectrometry, by using a high-purity germanium detector (HPGe) coupled to a multichannel analyzer. Activity concentration for 238 U and 232 Th in zircon sands ranged from 5462±143 to 19286±46 Bq kg -1 and from 1016±7 to 7162±38 Bq kg -1 , respectively. For 40 K, on the other hand, activity concentration values ranged from 81±14 to 681±26 Bq Kg -1 . The results of the measurements carried out for raw sand samples showed activity concentrations between 2.7±0.6 and 7.9±0.9 Bq kg -1 and 6.5±0.4 and 9.4±0.6 Bq kg -1 for 238 U and 23T h respectively, and from 48.8±3.1 to 76.1±2.4 Bq kg -1 for 40 K. Activity concentrations of 238 U and 232 Th in kyanite, ilmenite and rutile samples were also determined. (author)

  17. Separation and purification of uranium product from thorium in thorex process by precipitation technique

    International Nuclear Information System (INIS)

    Ramanujam, A.; Dhami, P.S.; Gopalakrishnan, V.; Mukherjee, A.; Dhumwad, R.K.

    1989-01-01

    A sequential precipitation technique is reported for the separation of uranium and thorium present in the uranium product stream of a single cycle 5 per cent TBP Thorex Process. It involves the precipitation of thorium as oxalate in 1M HNO 3 medium at 60-70degC and after filtration, precipitation of uranium as ammonium diuranate at 80-90degC from the oxalate supernatant. This technique has several advantages over the ion-exchange process normally used for treating these products. In order to meet the varying feed conditions, this method has been tested for feeds containing 10 g/1 uranium and 1-50 g/1 thorium in 1-6M HNO 3 . Various parameters like feed acidities, uranium and thorium concentrations, excess oxalic acid concentrations in the oxalate supernatant, precipitation temperatures, precipitate wash volumes etc. have been optimised to obtain more than 99 per cent recovery of thorium and uranium as their oxides with less than 50 ppm uranium losses to ammonium diuranate filtrate. The distribution patterns of different fission products and stainless steel corrosion products during various steps of this procedure have also been studied. For simulating the actual Thorex plant scale operation, experiments have been conducted with 25g and 100g lots of uranium per batch. (author). 6 tabs., 8 figs., 22 refs

  18. Influence of plant activity and phosphates on thorium bioavailability in soils from Baotou area, Inner Mongolia

    International Nuclear Information System (INIS)

    Guo Pengran; Jia Xiaoyu; Duan Taicheng; Xu Jingwei; Chen Hangting

    2010-01-01

    Harm of thorium to living organisms is governed by its bioavailability. Thorium bioavailability in the soil-plant system of Baotou rare earth industrial area was studied using pot experiments of wheat and single extraction methods. The effects of wheat growth stage and phosphate on thorium bioavailability were also investigated. Based on extractabilities of various extraction methods (CaCl 2 , NH 4 NO 3 , EDTA, HOAc) and correlation analysis of thorium uptake by wheat plant and extractable thorium, a mixture of 0.02 M EDTA + 0.5 M NH 4 OAc (pH 4.6) was found suitable for evaluation of thorium bioavailability in Baotou soil, which could be predicted quantitatively by multiple regression models. Because of differences of wheat root activities, thorium bioavailability in rhizosphere soil was higher than in bulk soil at tillering stage, but the reverse occurred at jointing stage. Phosphate addition induced the mineralization of soluble thorium by forming stable thorium phosphate compounds, and reduced thorium bioavailability in soil.

  19. Influence of plant activity and phosphates on thorium bioavailability in soils from Baotou area, Inner Mongolia

    Energy Technology Data Exchange (ETDEWEB)

    Guo Pengran [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Science, 5625 Renmin Street, Changchun, Jilin 130022 (China); School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Jia Xiaoyu; Duan Taicheng; Xu Jingwei [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Science, 5625 Renmin Street, Changchun, Jilin 130022 (China); Chen Hangting, E-mail: guopengran@gmail.co [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Science, 5625 Renmin Street, Changchun, Jilin 130022 (China)

    2010-09-15

    Harm of thorium to living organisms is governed by its bioavailability. Thorium bioavailability in the soil-plant system of Baotou rare earth industrial area was studied using pot experiments of wheat and single extraction methods. The effects of wheat growth stage and phosphate on thorium bioavailability were also investigated. Based on extractabilities of various extraction methods (CaCl{sub 2}, NH{sub 4}NO{sub 3}, EDTA, HOAc) and correlation analysis of thorium uptake by wheat plant and extractable thorium, a mixture of 0.02 M EDTA + 0.5 M NH{sub 4}OAc (pH 4.6) was found suitable for evaluation of thorium bioavailability in Baotou soil, which could be predicted quantitatively by multiple regression models. Because of differences of wheat root activities, thorium bioavailability in rhizosphere soil was higher than in bulk soil at tillering stage, but the reverse occurred at jointing stage. Phosphate addition induced the mineralization of soluble thorium by forming stable thorium phosphate compounds, and reduced thorium bioavailability in soil.

  20. Preliminary concepts: coordinated safeguards for materials management in a thorium--uranium fuel reprocessing plant

    International Nuclear Information System (INIS)

    Hakkila, E.A.; Barnes, J.W.; Dayem, H.A.; Dietz, R.J.; Shipley, J.P.

    1978-10-01

    This report addresses preliminary concepts for coordinated safeguards materials management in a typical generic thorium--uranium-fueled light-water reactor (LWR) fuels reprocessing plant. The reference facility is designed to recover thorium and uranium from first-generation (denatured 235 U) startup fuels, first-recycle and equilibrium (denatured 233 U) thorium--uranium LWR fuels, and to recover the plutonium generated in the 238 U denaturant as well. 12 figures, 3 tables

  1. Effect of Thorium on Growth and Uptake of Some Elements by Maize Plant

    International Nuclear Information System (INIS)

    Al-Shobaki, M.E.E.

    2012-01-01

    A pot experiment (sand culture) was carried out to investigate the effect of thorium on maize dry matter yield, contents and uptake of N,P ,K, Na and Fe and thorium accumulation in maize plant.The pots were contaminated by thorium as Thorium Nitrate(Th (NO 3 ) 4 ,H 2 O)at concentrations 0,5,10,11,12,13,14,15 and 50 ppm. Pots irrigated by 1/10 Hogland solution for 15 days, increased tol/4 Hogland solution after that.The results show that the dry matter (shoot, root and whole plant)decreased with increasing thorium concentration in soil up to 12 ppm and slightly increased with increasing Th to 13 ppm . The Nitrogen content and its uptake decreased with increasing thorium concentration in media growth up to 11 ppm .They were slightly increased at Th concentration between 11-14 ppm in maize shoot and root. The shoots always contained N-content and uptake more than that found in roots . P- uptake decreased in both shoots and roots with increasing in thorium concentration in media growth.

  2. Thorium determination by X-ray Fluorescence Spectrometry in simulated thorex process solutions

    International Nuclear Information System (INIS)

    Yamaura, M.; Matsuda, H.T.

    1989-01-01

    The X-ray fluorescence method for thorium determination in aqueous and organic (TBP-n-dodecane) solutions is described. The thin film-technique for sample preparation and a suitable internal standard have been used. Some parameters as analytical line, internal standard, filter paper, paper geometry, sample volume and measurement conditions were studied. Uranium, fission products, corrosion products and thorex reagent components were studied as interfering elements in the thorium analysis, as well as the matrix effect by using the thorex process simulated solutions the method to thorium determination in irradiated thorium solutions was applied. (M.J.C.) [pt

  3. Behavior of radioactive elements (uranium and thorium) in Bayer process

    International Nuclear Information System (INIS)

    Sato, C.; Kazama, S.; Sakamoto, A.; Hirayanagi, K.

    1986-01-01

    It is essential that alumina used for manufacturing electronic devices should contain an extremely low level of alpha-radiation. The principal source of alpha-radiation in alumina is uranium, a minor source being thorium. Uranium in bauxite dissolves into the liquor in the digestion process and is fixed to the red mud as the desilication reaction progresses. A part of uranium remaining in the liquor precipitates together with aluminum hydroxide in the precipitation process. The uranium content of aluminum hydroxide becomes lower as the precipitation velocity per unit surface area of the seed becomes slower. Organic matters in the Bayer liquor has an extremely significant impact on the uranium content of aluminum hydroxide. Aluminum hydroxide free of uranium is obtainable from the liquor that does not contain organic matters

  4. 75 FR 71677 - Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites

    Science.gov (United States)

    2010-11-24

    ... DEPARTMENT OF ENERGY Reimbursement for Costs of Remedial Action at Active Uranium and Thorium... in FY 2011 from eligible active uranium and thorium processing site licensees for reimbursement under... approximately $24.3 million of Recovery Act funds available for reimbursement in FY 2011, as well as the $10...

  5. Recovery of radiogenic lead-208 from a residue of thorium and rare earths obtained during the operation of a thorium nitrate purification pilot plant

    International Nuclear Information System (INIS)

    Seneda, Jose Antonio

    2006-01-01

    Brazil has a long tradition in thorium technology, from mineral dressing (monazite) to the nuclear grade thorium compounds. The estimate reserves are 1200,000. ton of ThO 2 . As a consequence from the work of thorium purification pilot plant at Instituto de Pesquisas Energeticas e Nucleares-CNEN/SP, about 25 ton of a sludge containing thorium and rare earths was accumulated. It comes as a raffinate and washing solutions from thorium solvent extraction. This sludge, a crude hydroxide named RETOTER contains thorium, rare earths and minor impurities including the radiogenic lead-208, with abundance 88.34 %. This work discusses the results of the studies and main parameters for its recovery by anionic ion exchange technique in the hydrochloric system. The isotope abundance of this lead was analyzed by high resolution mass spectrometer (ICPMS) and thermoionic mass spectrometer (TIMS) and the data was used to calculate the thermal neutron capture cross section. The value of s ? o = 14.6 +/- 0.7 mb was found, quite different from the s ? o = 174.2 +/- 7.0 mb measure cross section for the natural lead. Preliminary study for the thorium and rare earths separation and recovery was discussed as well. (author)

  6. Recovery of radiogenic lead-208 from a residue of thorium and rare earths obtained during the operation of a thorium purification pilot plant

    International Nuclear Information System (INIS)

    Seneda, Jose Antonio

    2006-01-01

    Brazil has a long tradition in thorium technology, from mineral dressing (monazite) to the nuclear grade thorium compounds. The estimate reserves are 1200,000. ton of ThO 2 . As a consequence from the work of thorium purification pilot plant at Instituto de Pesquisas Energeticas e Nucleares-CNEN/IPEN-SP, about 25 ton of a sludge containing thorium and rare earths was accumulated. It comes as a raffinate and washing solutions from thorium solvent extraction. This sludge, a crude hydroxide named RETOTER contains thorium, rare earths and minor impurities including the radiogenic lead-208, with abundance 88.34 %. This work discusses the results of the studies and main parameters for its recovery by anionic ion exchange technique in the hydrochloric system. The isotope abundance of this lead was analyzed by high resolution mass spectrometer (ICPMS) and thermoionic mass spectrometer (TIMS) and the data was used to calculate the thermal neutron capture cross section. The value of σγ 0 = 14.6±0.7 mb was found, quite different from the σγ 0 = 174.2 ± 7.0 mb measure cross section for the natural lead. Preliminary study for the thorium and rare earths separation and recovery was discussed as well. (author)

  7. Health physics experience on the decommissioning of Thorium plant of IRE Ltd. at Trombay

    International Nuclear Information System (INIS)

    Savant, P.B.; Venkata Rao, D.V.; Rangarajan, R.; Pushparaja

    2003-01-01

    Thorium plant which was in operation for the last 45 years at Trombay, was decommissioned during the period 1999-2001. The decommissioning operation was spread over a period of 18 months. Over the years of operations, considerable activity was build-up was on the plant equipment and supporting structures. A new plant is erected at OSCOM to meet the thorium nitrate requirement. In view of the aging of the process equipment and resulting increase in the Person-Sv expenditure, it was decided to decommission the plant at Trombay. Decommissioning work is a voluminous job and hence required a careful planning of manpower, budgeting of personnel exposures and safe transfer of radioactive wastes. A considerable reduction in the budgeted man- days was achieved by using appropriate machinery and modern gadgets. A total of 3465 man-days were utilised for the work. 40 contract labourers were engaged in two phases. The total dose received was 123.32 Person-mSv as against the budgeted 189.29 Person-mSv for the entire operation. The maximum individual whole body dose received was 4.5 mSv. Around 2000 m 3 of low level radioactive solid waste was disposed off. Chipping of walls and floor has resulted in reduction of the volume of low level waste by as much as 766 m 3 as compared-to estimated volume of 4000 m 3 . This paper discusses briefly the experience gained by the RHC Unit in providing RHC surveillance for the decommissioning work. (author)

  8. Distribution of uranium and thorium in sediments and plants from a granitic fluvial area

    International Nuclear Information System (INIS)

    Vargas, M.J.; Tome, F.V.; Sanchez, A.M.; Vazquez, M.T.C.; Murillo, J.L.G.

    1997-01-01

    A study of the presence of natural uranium and thorium isotopes in sediments and plants belonging to a granitic fluvial region of the Ortigas river (west of Spain) has been carried out. The existence of two uranium mines in the neighbourhood of the sampled sites and the granitic characteristics of the zone produce significant concentrations of natural radionuclides. Temporal and spatial variations of uranium and thorium concentrations and the activity ratios 234 U/ 238 U, 228 Th/ 232 Th and Th/U were studied to better understand the mobilization mechanisms such as leaching and transport at play in the studied system. These determinations were made using alpha-particle spectrometry with silicon detectors. The measurements were also compared with the results previously found for waters of this fluvial area. Uranium in sediments showed variations due to changes in rainfall, but thorium content was nearly constant. Uranium and thorium concentrations in plants were lower after rainfall. Incorporation of uranium into the plants seemed to be mainly from water, whereas incorporation of thorium seemed to be from both sediments and water. (Author)

  9. Uranium and thorium recovery from a sub-product of monazite industrial processing

    International Nuclear Information System (INIS)

    Gomiero, L.A.; Ribeiro, J.S.; Scassiotti Filho, W.

    1994-01-01

    In the monazite alkaline leaching industrial process for the production of rare earth elements, a by-product is formed, which has a high concentration of thorium and a lower but significant one of uranium. A procedure for recovery of the thorium and uranium contents in this by-product is presented. The first step of this procedure is the leaching with sulfuric acid, followed by uranium extraction from the acid liquor with a tertiary amine, stripping with a Na Cl solutions and precipitation as ammonium diuranate with N H 4 O H. In order to obtain thorium concentrates with higher purity, it is performed by means of the extraction of thorium from the acid liquor, with a primary amine, stripping by a Na Cl solution and precipitation as thorium hydroxide or oxalate. (author)

  10. Flowchart evaluations of irradiated fuel treatment process of low burnup thorium

    International Nuclear Information System (INIS)

    Linardi, M.

    1987-01-01

    A literature survey has been carried out, on some versions of the acid-thorex process. Flowsheets of the different parts of the process were evaluated with mixer-settlers experiments. A low burnup thorium fuel (mass ratio Th/U∼100/1), proposed for Brazilian fast breeder reactor initial program, was considered. The behaviour of some fission products was studied by irradiated tracers techniques. Modifications in some of the process parameters were necessary to achieve low losses of 233 U and 232 U and 232 Th. A modified acid-thorex process flowsheet, evaluated in a complete operational cycle, for the treatment of low burnup thorium fuels, is presented. High decontamination factors of thorium in uranium, with reasonable decontamination of uranium in thorium, were achieved. (author) [pt

  11. Process for electroforming nickel containing dispersed thorium oxide particles therein

    International Nuclear Information System (INIS)

    Malone, G.A.

    1975-01-01

    Nickel electroforming is effected by passing a direct current through a bath containing a dissolved nickel salt or a mixture of such salts, such as those present in sulfamate or Watts baths, and finely divided sol-derived thorium oxide particles of 75 to 300 angstroms, preferably 100 to 200 angstroms diameters therein, at a pH in the range of 0.4 to 1.9, preferably 0.8 to 1.3. The nickel so deposited, as on a pre-shaped stainless steel cathode, may be produced in desired shape and may be removed from the cathode and upon removal, without additional working, possesses desirable engineering properties at elevated temperatures, e.g., 1,500 to 2,200 0 F. Although the material produced is of improved high temperature stability, hardness, and ductility, compared with nickel alone, it is still ductile at room temperature and has properties equivalent or superior to nickel at room temperatures up to 1,500 0 F. Further improvements in mechanical properties of the material may be obtained by working. Also disclosed are electrodeposition baths, methods for their manufacture, and products resulting from the electrodeposition process. (U.S.)

  12. Thorium determination by x-ray fluorescence spectrometry in simulated thorex process solutions

    International Nuclear Information System (INIS)

    Yamaura, M.; Matsuda, H.T.

    1991-11-01

    The X-ray fluorescence method for thorium determination in aqueous and organic (TBP/n-dodecane) solutions is described. The thin film technique for sample preparation and a suitable internal standard had been used. The best conditions for Thorium determination had been established studying some parameters as analytical line, internal standard, filter paper, paper geometry, sample volume and measurement conditions. With the established conditions, thorium was concentration range of to 200 g Th/L and in organic solutions (2-63g Th/L) with 1,5% of precision. The accuracy of the proposed method was 3% in aqueous and organic phases. The detection limit was 1,2μg thorium for aqueous solutions and 1,4μg for organic solutions. Uranium, fission products, corrosion products and Thorex reagent components were studied as interfering elements in the thorium analysis. The matrix effect was also studied using the Thorex process simulated solutions. Finally, the method was applied to thorium determination in irradiated thorium solutions with satisfactory results. (author)

  13. Biogeochemical investigation in south eastern Andhra Pradesh: the distribution of rare earths, thorium and uranium in plants and soils

    International Nuclear Information System (INIS)

    Raju, K.K.; Raju, A.N.

    2000-01-01

    The concentration of rare earth elements (REE), thorium and uranium were determined by inductively coupled plasma mass spectrometry (ICP-MS) in the plant species, Pterocarpus santalinus, P. marsupium and P. dalbergioides, and the soils on which they were growing. Higher concentrations of lanthanum (La), cerium (Ce) were observed in both plants and soils. Large amounts of thorium and uranium were found in the soil. In all tree species, the concentration of REEs were higher in the heartwood than the leaves. The heartwood of P. santalinus accumulated larger quantities of uranium (average concentration of 1.22 ppm) and thorium (mean value of 2.57 ppm) than the other two species. (orig.)

  14. Chlorine gas processing of oxide nuclear fuel particles containing thorium

    International Nuclear Information System (INIS)

    Knotik, K.; Bildstein, H.; Falta, G.; Wagner, H.

    Experimental studies on the chloride extraction and separation of U and Th from coated Th--U oxide particles are reported. After a description of the chlorination equipment and the experimental procedures, the results are discussed. The yield of U is determined as a function of the reaction temperature. The results of a thermogravimetric analysis of the chlorination of uranium carbide and thorium carbides are reported and used to establish the reaction mechanism for the chlorination

  15. Studies about the assimilation of thorium by plants in Morro do Ferro (MG)

    International Nuclear Information System (INIS)

    Dotto, R.M.

    1985-01-01

    The following aspects of thorium mobilization and bioassimilation are studied: the determination of Th-232 concentrations in typical plants indigenous to the Morro do Ferro environment; the behaviour of different complexing agents, including humic acids, to assess their effectiveness in solubilizing Th-232 from soils and weathered ore; assessment of the importance of these complexing agents in the bioassimilation of Th-232. Leaching experiments with soil and weathered ore samples demonstrate that Th-232 release increases in the order: water [pt

  16. Dosimetric assessment from 212Pb inhalation at a thorium purification plant

    International Nuclear Information System (INIS)

    Campos, M. P.; Pecequilo, B. R. S.

    2004-01-01

    At the Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo (Brazil)), there is a facility (thorium purification plant) where materials with high thorium concentrations are manipulated. In order to estimate afterwards the lung cancer risk for the workers, the thoron daughter ( 212 Pb) levels were assessed and the committed effective and lung committed equivalent doses for workers in place. A total of 28 air filter samples were measured by total alpha counting through the modified Kusnetz method, to determine the 212 Pb concentration. The committed effective dose and lung committed equivalent dose due to 212 Pb inhalation were derived from compartmental analysis following the ICRP 66 lung compartmental model, and ICRP 67 lead metabolic model. (authors)

  17. Processing of Indian monazite for the recovery of thorium and uranium values

    International Nuclear Information System (INIS)

    Mukherjee, T.K.

    2004-01-01

    The mineral monazite, a phosphate of rare earths and thorium with significant quantity of uranium is one of the six heavy minerals present in the beach sands of specific coastal areas of India. Indian Rare Earths Ltd is mining and processing monazite at its Rare Earths Division for the last many decades with an aim of building up enough stock of thorium concentrate for its future use in the three stage nuclear power programme of the country. The present paper briefly describes the monazite resource position of he country, the past and present modified processing schemes and the future programme commensurate with the requirement of the country for quality thorium and uranium bearing nuclear materials

  18. Analysis of Uranium and Thorium in Radioactive Wastes from Nuclear Fuel Cycle Process

    International Nuclear Information System (INIS)

    Gunandjar

    2008-01-01

    The assessment of analysis method for uranium and thorium in radioactive wastes generated from nuclear fuel cycle process have been carried out. The uranium and thorium analysis methods in the assessment are consist of Titrimetry, UV-VIS Spectrophotometry, Fluorimetry, HPLC, Polarography, Emission Spectrograph, XRF, AAS, Alpha Spectrometry and Mass Spectrometry methods. From the assessment can be concluded that the analysis methods of uranium and thorium content in radioactive waste for low concentration level using UV-VIS Spectrometry is better than Titrimetry method. While for very low concentration level in part per billion (ppb) can be used by Neutron Activation Analysis (NAA), Alpha Spectrometry and Mass Spectrometry. Laser Fluorimetry is the best method of uranium analysis for very low concentration level. Alpha Spectrometry and ICP-MS (Inductively Coupled Plasma Mass Spectrometry) methods for isotopic analysis are favourable in the precision and accuracy aspects. Comparison of the ICP-MS and Alpha Spectrometry methods shows that the both of methods have capability to determining of uranium and thorium isotopes content in the waste samples with results comparable very well, but the time of its analysis using ICP-MS method is faster than the Alpha Spectrometry, and also the cost of analysis for ICP-MS method is cheaper. NAA method can also be used to analyze the uranium and thorium isotopes, but this method needs the reactor facility and also the time of its analysis is very long. (author)

  19. Quantitative regularities of magnesium, calcium, radium-226, and thorium migration from soils to plants

    International Nuclear Information System (INIS)

    Ashkinazi, Eh.I.

    1980-01-01

    Concentrations of magnesium, calcium, radium 226, thorium 228 in podsolized chernozem and grey medium-loamy soils were determined under conditions of ordinary farming. Concentrations of these elements were determined in soils and main agricultural plants: wheat, barley, peas, potatoes, beets, and carrots. Transition coefficients of magnesium, calcium, and radium 226 from soils to plants were calculated and the following series of transition coefficients were determined: to Mg> to Ca> to Ra. Transition coefficients from dern-podsolic soils were 3-27 times higher than from chernozem

  20. Process for selectively concentrating the radioactivity of thorium containing magnesium slag

    International Nuclear Information System (INIS)

    Wilson, D.A.; Christiansen, S.H.; Simon, J.; Morin, D.W.

    1993-01-01

    In a process for separating magnesium from a magnesium slag using water and carbon dioxide, the improvement described comprises: (a) forming an aqueous magnesium slurry from the magnesium slag, which slag contains radioactive thorium and its daughters, and water; (b) solubilizing magnesium from the magnesium slurry by reacting the aqueous magnesium slurry with carbon dioxide wherein the carbon dioxide is at a pressure from greater than ambient to about 1,000 psig (about 7,000 kPa); (c) selectively concentrating by filtering the radioactive thorium and its daughters such that the radioactive thorium and its daughters are separated from the solubilized magnesium filtrate; and (d) reducing volume and/or weight of radioactive solids for disposal as radioactive waste

  1. Some processes affecting the mobility of thorium in natural ground waters

    International Nuclear Information System (INIS)

    Oesthols, E.

    1994-04-01

    Thorium is a useful model element for tetravalent actinides such as U(IV), Pu(IV) and Np(IV) which are important constituents of spent nuclear fuel. Thorium is also an important tracer element for particle pathways in natural environments. In order to correctly model the transport of Th in the environment, it is important to have quantitative models for processes that effect its mobility. Some of these processes have been experimentally investigated in laboratory studies, and interpreted with quantitative models where possible. The carbonate complexation in aqueous solution of Th has been investigated through solubility studies of ThO 2 in carbonate media. It is shown, that thorium carbonate complexes are likely to be predominant in many natural waters. They also increase solubility of the oxide significantly, and hence the mobility of Th. Carbonate also increases the dissolution rate of thorium oxide. This effect will only be important in environments with a pH and total carbonate alkalinity higher than those of most natural aquatic environments. Solubility studies of thorium oxide in phosphate media show that phosphate does not significantly increase the mobility of Th in aqueous media. The presence of phosphate may cause the precipitation of sparingly soluble thorium phosphates which will decrease the mobility of Th. The pentahydroxo complex for Th is shown to be significant up to pH 13. Potentiometric studies of Th sorption on amorphous colloidal silica indicate, that pure aluminosilicates will probably not be efficient scavengers of tetravalent actinides above pH values of approximately 6. In neutral to alkaline solutions, iron (hydr)oxides are likely to be the predominant sorbents. Th binds to the silica surface through corner-sharing bonds, where Th and Si share one, but not more oxygen atoms. 72 refs

  2. Recovery of thorium from monazite

    International Nuclear Information System (INIS)

    Karve, V.M.; Mukherjee, T.K.

    1997-01-01

    The process practised in the monazite processing plant involves caustic soda digestion of finely ground monazite followed by aqueous processing to recover mixed rare earth chloride solution, thorium and uranium values in the form of hydroxide cake and tri sodium phosphate as a byproduct

  3. Asymmetrically deformed states of thorium isotopes during fission process

    International Nuclear Information System (INIS)

    Blons, J.

    1982-05-01

    Some theoretical considerations are recalled on fission barriers calculated from macroscopic, microscopic or macroscopic-microscopic and ''thorium anomaly'' problem is set. Experimental techniques used to measure fission cross sections in (n,f) reactions near the threshold are described. Fission dectector is described; stray resonance problems and retrodiffused neutrons are discussed. Results obtained in experimental study of 230 Th(n,f) and 232 Th(n,f) reactions are presented. They are compared with results obtained in other laboratories. The analysis model which allows to describe a (n,f) reaction is exposed. The compound nucleus formation cross section and transmission coefficients in neutron and gamma output channel are presented according to neutron energy for each value of angular moment and parity. Cross-section analysis and angular distribution obtained respectively in 230 Th(n,f) and 232 Th(n,f) reactions is exposed. Result interpretation show new aspects of nuclei rotational spectra and new nuclear forms [fr

  4. High Efficiency Nuclear Power Plants Using Liquid Fluoride Thorium Reactor Technology

    Science.gov (United States)

    Juhasz, Albert J.; Rarick, Richard A.; Rangarajan, Rajmohan

    2009-01-01

    An overall system analysis approach is used to propose potential conceptual designs of advanced terrestrial nuclear power plants based on Oak Ridge National Laboratory (ORNL) Molten Salt Reactor (MSR) experience and utilizing Closed Cycle Gas Turbine (CCGT) thermal-to-electric energy conversion technology. In particular conceptual designs for an advanced 1 GWe power plant with turbine reheat and compressor intercooling at a 950 K turbine inlet temperature (TIT), as well as near term 100 MWe demonstration plants with TITs of 950 and 1200 K are presented. Power plant performance data were obtained for TITs ranging from 650 to 1300 K by use of a Closed Brayton Cycle (CBC) systems code which considered the interaction between major sub-systems, including the Liquid Fluoride Thorium Reactor (LFTR), heat source and heat sink heat exchangers, turbo-generator machinery, and an electric power generation and transmission system. Optional off-shore submarine installation of the power plant is a major consideration.

  5. Recovery of valuable products in the raffinate of the uranium and thorium pilot-plant

    International Nuclear Information System (INIS)

    Jardim, E.A.; Abrao, A.

    1988-11-01

    IPEN-CNEN/SP has being very active in refining yellowcake to pure ammonium diuranate which is converted to uranium trioxide, uranium dioxide, tetra - and hexafluoride in a sequential way. The technology of the thorium purification and its conversion to nuclear grade products has been a practice since several years as well. For both elements the major to be worked is the raffinate from the solvent extraction colum where and thorium are purified via TBP-varsol in pulsed columns. In this paper the actual processing technology is reviewed with special emphasis on the recovery of valuable products, mainly nitric acid and ammonium nitrate. Distilled nitric acid and the final sulfuric acid as residue are recycle. Ammonium nitrate from the precipitation of uranium diuranate is of good quality, being radioactivity and uranium - free, and recommended to be applied as fertilizer. In conclusion the main effort is to maximize the recycle and reuse of the above mentioned chemicals. (author) [pt

  6. Recovery of valuable products from the raffinate of uranium and thorium pilot-plant

    International Nuclear Information System (INIS)

    Martins, E.A.J.

    1990-01-01

    IPEN-CNEN/SP has being very active in refining yellow cake to pure ammonium diuranate which is converted to uranium trioxide, uranium dioxide, uranium tetra-and hexa-fluoride in sequential way. The technology of the thorium purification and its conversion to nuclear grade products has been a practice since several years as well. For both elements the major waste to be worked is the raffinate from purification via TBP-varsol in pulsed columns. In this paper the actual processing technology is reviewed with special emphasis on the recovery of valuable products, mainly nitric acid, ammonium nitrate, uranium, thorium and rare earth elements. Ammonium nitrate from the precipitation of uranium diuranate is of good quality, being radioactivity and uranium-free, and recommended to be applied as fertilizer. In conclusion the main effort is to maximize the recycle and reuse of the above mentioned chemicals. (author)

  7. A novel process for the synthesis of 'Designed Molecular Precursor' (DMP) of thorium useful for broad application spectrum

    International Nuclear Information System (INIS)

    Sarika Verma; Amritphalae, S.S.

    2016-01-01

    For the first time (Patent application filed in India vide N/F No-0018NF2015) a novel process for the synthesis of 'Designed Molecular Precursor' (DMP) of thorium has been developed, which involves the unique combination of two different (dual) capping agents, one is biomolecule: Cytosine and other is non biomolecule: cetyl trimethyl ammonium bromide. The DMP essentially consists of hybrid nanosized thorium oxalate and alkaline thorate whose application lies in the area of making thorium metal, densified thorium oxide, carbide and nitride, anhydrous thorium complexes and thorium boron silicates glasses. (author)

  8. Quantitative laws governing the migration of magnesium, calcium, radium-226, thorium-228 in the link between soils and plants

    International Nuclear Information System (INIS)

    Ashkinazi, E.I.

    1982-02-01

    Concentrations of magnesium, calcium, radium 226 and thorium 228 in podsolized chernozem and medium-loamy soils and in agricultural plants (wheat, barley, peas, potatoes, beets, and carrots) were determined. Transition coefficients of magnesium, calcium and radium 226 from soils to plants were calculated

  9. Review of thorium fuel reprocessing experience

    International Nuclear Information System (INIS)

    Brooksbank, R.E.; McDuffee, W.T.; Rainey, R.H.

    1978-01-01

    The review reveals that experience in the reprocessing of irradiated thorium materials is limited. Plants that have processed thorium-based fuels were not optimized for the operations. Previous demonstrations of several viable flowsheets provide a sound technological base for the development of optimum reprocessing methods and facilities. In addition to the resource benefit by using thorium, recent nonproliferation thrusts have rejuvenated an interest in thorium reprocessing. Extensive radiation is generated as the result of 232 U-contamination produced in the 233 U, resulting in the remote operation and fabrication operations and increased fuel cycle costs. Development of the denatured thorium flowsheet, which is currently of interest because of nonproliferation concerns, represents a difficult technological challenge

  10. Comparative uptake of thorium-230, radium-226, lead-210 and polonium-210 by plants

    Energy Technology Data Exchange (ETDEWEB)

    D' Souza, T J; Mistry, K B

    1970-01-01

    The entry and translocation of /sup 230/thorium, /sup 226/radium, /sup 210/lead, and /sup 210/polonium were examined in nutrient culture experiments. Strontium-89 was included for comparison. Red kidney beans (Phaseolus vulgaris L.) were treated for a period of 15 days. Results indicate that accumulation of /sup 230/thorium, /sup 210/lead and /sup 210/polonium occurs predominantly in roots and only very small amounts of these nuclides are translocated to shoots. Over comparable periods, the accumulation of /sup 226/radium in roots is 2-3 times lower than that of the other nuclides of uranium series. However, the most significant difference between /sup 226/radium and other nuclides is in the extent of their upward transport which for radium is 50-200 times greater. The amount of radium translocated to shoots is comparable to that of strontium. The present evidence of rapid transfer of /sup 226/radium to shoots suggests that among the nuclides examined, /sup 226/radium is likely to make the major contribution to radioactivity in aerial tissues of plants grown under conditions where root absorption is the principal route of entry of the nuclides.

  11. Process control guidelines for CY 70 thorium campaign

    International Nuclear Information System (INIS)

    Jackson, R.R.

    1970-01-01

    The report comprises five parts, with part I being an introduction. Part II consists of a general treatment of process control methods. Parts III through V discuss, in the flowsheet sequence, those problems pertinent to each equipment piece or system and provide operating guidelines. Specific operations that are somewhat different from those normally encountered in Purex are discussed at length. Operations routine to Purex can be found in the pertinent standard operating procedures. Part VI describes in general terms the sequence to be followed in initiating and completing a variety of transient conditions

  12. Status of thorium technology

    International Nuclear Information System (INIS)

    Garg, R.K.; Raghavan, R.V.; Karve, V.M.; Narayandas, G.R.

    1977-01-01

    Although a number of studies have been conducted in various countries to evolve reactor systems based on thorium fuel cycle, its use, so far, is limited to only a few reactors. However, for countries having large reserves of thorium, its utilization is of great significance for their nuclear power programmes. Reasonably assured world resources of thorium in the lower price range have been estimated at more than 500,000 tons of ThO 2 . While most of these resources are in placer deposits in various parts of the world, some vein deposits and uranium ores are other important sources of thorium. Monazite, the most important mineral of thorium, is found in the beach sand deposits along with other heavy minerals like ilmenite, rutile, zircon, and sillimanite etc. Mining of these deposits is usually carried out by suction dredging and separation of monazite from other minerals is effected by a combination of magnetic, electrostatic and gravity separation techniques. Chemical processing of monazite is carried out either by sulphuric acid or caustic treatment, followed by separation of the rare earths and thorium by partial precipitation or leaching. The thorium concentrate is further processed to obtain mantle grade thorium nitrate by chemical purification steps whereas solvent extraction using TBP is adopted for making nuclear-grade material. The purified thorium nitrate is converted to the oxide usually by precipitation as oxalate followed by calcination. The oxide is reduced directly with calcium or converted to the chloride or fluoride and then reduced by calcium or magnesium to obtain thorium metal. Various fuel designs based on the metal or its alloys, mixed oxides or carbides, and dispersed type fuel elements have been developed and accordingly, different fabrication techniques have been employed. Work on irradiation of thorium containing fuel elements and separation of U 233 is being carried out. This paper reviews the status of thorium technology in the world with

  13. Uranium and thorium nuclides series determined in medicinal plants commonly used in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Silva, P.; Francisconi, L.; Damatto, S. [IPEN/CNEN-SP, Sao Paulo (Brazil)

    2014-07-01

    In recent years the study of medicinal plants has become the focus of ever more extensive research all over the world due to their diversity and potential as source of medicinal products. According to the World Health Organization approximately 80% of world population makes use of medicinal herbs due to their believed therapeutic action. Besides being used as medicine, medicinal plants are also largely used as dietary supplements. The presence of radionuclides in plants constitutes one of the main pathways for their transfer to man. The amount of radioactive nuclides from U and Th series in edible vegetables are relatively well known since they have been the main concern of research conducted worldwide. Medicinal plants, on the other hand, have been neglected in these studies, possibly because the ingestion of radioactive material through their consumption has not been recognized or was considered insignificant. The objective of the present study was to determine the content of natural radionuclides from {sup 238}U and {sup 232}Th series in 25 species of medicinal plants used in Brazil, both as medicine and as dietary supplement. The medicinal plant samples were obtained in specialized pharmacies and drugstores. The raw plant and their extracts, produced as recommended by the National Agency for Sanitary Vigilance, were analyzed by Instrumental Neutron Activation Analyses for the determination of U and Th and by Total Alpha and Beta Counting after Radiochemical Separation for determination of {sup 226}Ra, {sup 228}Ra and {sup 210}Pb. In the raw plants the activity concentrations varied from 0,08 Bq kg{sup -1} to 8,0 Bq kg{sup -1} for thorium, from < LID to 22 Bq kg{sup -1} for uranium, from 1,8 Bq kg{sup -1} to 12 Bq kg{sup -1} for {sup 226}Ra, from 33 Bq kg{sup -1} to 74 Bq kg{sup -1} for {sup 228}Ra and from 10 Bq kg{sup -1} to 120 Bq kg{sup -1} for {sup 210}Pb. In the extracts, the activity concentrations varied from 9 mBq kg{sup -1} to 137 mBq kg{sup -1} for Th

  14. Estimation of annual dose equivalent (internal and external) for new thorium plant workers of IRE OSCOM, Orissa

    International Nuclear Information System (INIS)

    Vidya Sagar, D.; Tripathy, S.K.; Khan, A.H.; Maharana, L.N.

    2001-01-01

    In addition to thoron, thoron daughters and gamma radiation, the New Thorium Plant workers are exposed to long lived alpha emitters due to inhalation of thorium fine dust present in the working environment. Air samplers were used for measurement of thoron daughters and long lived alpha concentration. Each sample was counted for 3-4 hours for alpha activity and the long lived alpha concentration was calculated after taking the self absorption effect of the deposit on the filter paper into account. Internal dose of individual workers due to thoron daughter concentration and long lived alpha concentration was determined using time weighted factors. Based on the results, it is observed that contribution of thoron daughters, long lived alpha and external gamma is about 2 mSv /y, 1 mSv /y and 5 mSv/y, respectively, to total dose to the workers. (author)

  15. Uptake of uranium, thorium and radium isotopes by plants growing in dam impoundment Tasotkel and the Lower Shu region (Kazakhstan)

    Energy Technology Data Exchange (ETDEWEB)

    Matveyeva, Ilona; Burkitbayev, Mukhambetkali [al-Farabi Kazakh National University, Almaty (Kazakhstan). Faculty of Chemistry and Chemical Technology; Jacimovic, Radojko [Jozef Stefan Institute, Ljubljana (Slovenia). Dept. of Environmental Sciences; Planinsek, Petra; Smodis, Borut [Jozef Stefan Institute, Ljubljana (Slovenia). Dept. of Environmental Sciences; Jozef Stefan International Postgraduate School, Ljubljana (Slovenia)

    2016-04-01

    The activity concentrations of isotopes of uranium, thorium and radium-226 in dominant species of plants (Xantium strumarium, Phragmites communis, Artemisia nitrosa and Artemisia serotina) growing on the territories contaminated by uranium industry of Kazakhstan (close to dam impoundment Tasotkel and the Lower Shu region) are presented. The obtained data showed the significant variations of activity concentrations of isotopes of uranium, thorium and radium-226 in above ground parts. The concentrations of most of the investigated radionuclides in the root system are higher than in the aboveground parts; it can be explained by root barrier. It was found that the highest root barrier has Xantium strumarium, especially for uranium isotopes. The concentration ratios of radionuclides were calculated, and as the result it was found that the highest accumulation ability in the investigated region has Artemisia serotina.

  16. Uptake of uranium, thorium and radium isotopes by plants growing in dam impoundment Tasotkel and the Lower Shu region (Kazakhstan)

    International Nuclear Information System (INIS)

    Matveyeva, Ilona; Burkitbayev, Mukhambetkali

    2016-01-01

    The activity concentrations of isotopes of uranium, thorium and radium-226 in dominant species of plants (Xantium strumarium, Phragmites communis, Artemisia nitrosa and Artemisia serotina) growing on the territories contaminated by uranium industry of Kazakhstan (close to dam impoundment Tasotkel and the Lower Shu region) are presented. The obtained data showed the significant variations of activity concentrations of isotopes of uranium, thorium and radium-226 in above ground parts. The concentrations of most of the investigated radionuclides in the root system are higher than in the aboveground parts; it can be explained by root barrier. It was found that the highest root barrier has Xantium strumarium, especially for uranium isotopes. The concentration ratios of radionuclides were calculated, and as the result it was found that the highest accumulation ability in the investigated region has Artemisia serotina.

  17. Global recovery process of thorium and rare earths in a nitrate medium

    International Nuclear Information System (INIS)

    Cailly, F.; Mottot, Y.

    1993-01-01

    The aqueous solution of thorium and rare earth nitrates, obtained by leaching the ore with nitric acid, is extracted by an organic phosphorous compound (phosphate, phosphonate, phosphinate or phosphine oxide) and a cationic extractant chosen among phosphoric acid di-esters. Extraction of thorium and rare earths is possible even in presence of phosphate ions in the aqueous solution. Thorium and rare earths are separated by liquid-liquid extraction of the organic phase

  18. Radiation protection in thorium industry

    International Nuclear Information System (INIS)

    Moraes, A.

    1977-01-01

    The evaluation of radiation doses in a monazite processing plant (thorium production cycle) aiming to getting information on the exposure levels to beta and gamma radiation, is discussed. It is observed that, excluding places where monazite is stored,or during transportation, or in silos, or waste deposits, or in places where high activity materials are stored or treated, the externa exposure stay below the maximum pemissible limit. Some recommendations are made based on the results found and according to radiation protection standards

  19. Study of the effect of uranium and thorium on the growing of pepper (Capsicum annuum var. longum) and cucumber (Cucumis sativus) plants

    International Nuclear Information System (INIS)

    Uenak, T.; Yildirim, Y.; Tokucu, G.; Uenak, G.; Oecal, J.; Konyali, D.; Kilic, S.

    2007-01-01

    The transportation rate of uranium and thorium to different plants grown in soils having high level of these elements varies closely with the plant characteristics. In this study, the pepper (Capsicum annuum var. longum) and cucumber (Cucumis sativus) plants were chosen as vegetables which are commonly consumed over different regions by different populations. The results obtained can be summarized as follows: (1) High uranium concentration in the soil prevents the growing of the plants. Only the plants in the pot having the uranium concentration of about 263 ppm grew significantly. The plants in other pots having a higher concentration turned pale and died in a few weeks. (2) In the pot having thorium level of about 263 ppm, the plants were well grown and fruited in comparison to the control plants, but the increase of thorium concentration inversely influenced their growing. (3) The gross activities measured in different parts of the plants were not particularly high, however, in both cases the maximum activities were measured in the stems rather than in the fruits and leaves. (4) The plants grown in soils having thorium content lived longer than the control plants and at the greenhouse conditions indicated above, all plants lived more than one whole year flowering and fruiting. (author)

  20. Thorium Molten Salt Nuclear Energy Synergetic System (THORIMS-NES)

    International Nuclear Information System (INIS)

    Yoshioka, Ritsuo; Mitachi, Koshi

    2013-01-01

    The authors have been promoting nuclear energy technology based on thorium molten salt as Thorium Molten Salt Nuclear Energy Synergetic System (THORIMS-NES). This system is a combination of fission power reactor of Molten Salt Reactor (MSR), and Accelerator Molten Salt Breeder (AMSB) for production of fissile 233 U with connecting chemical processing facility. In this paper, concept of THORIMS-NES, advantages of thorium and molten salt recent MSR design results such as FUJI-U3 using 233 U fuel, FUJI-Pu, large sized super-FUJI, pilot plant miniFUJI, AMSB, and chemical processing facility are described. (author)

  1. Uranium and thorium concentration process during partial fusion and crystallization of granitic magma

    International Nuclear Information System (INIS)

    Cuney, M.

    1982-01-01

    Two major processes, frequently difficult to distinguish, lead to uranium and thorium enrichment in igneous rocks and more particularly in granitoids; these are partial melting and fractional crystallization. Mont-Laurier uranothoriferous pegmatoids, Bancroft and Roessing deposits are examples of radioelement concentrations resulting mostly of low grade of melting on essentially metasedimentary formations deposited on a continental margin or intracratonic. Fractional crystallization follows generally partial melting even in migmatitic areas. Conditions prevailing during magma crystallization and in particular oxygen fugacity led either to the formation of uranium preconcentrations in granitoids, or to its partition in the fluid phase expelled from the magma. No important economic uranium deposit appears to be mostly related to fractional crystallization of large plutonic bodies

  2. 76 FR 30696 - Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites

    Science.gov (United States)

    2011-05-26

    ... in the reimbursement ceilings). Title X requires DOE to reimburse eligible uranium and thorium... DEPARTMENT OF ENERGY Reimbursement for Costs of Remedial Action at Active Uranium and Thorium... reimbursement under Title X of the Energy Policy Act of 1992. In our Federal Register Notice of November 24...

  3. 76 FR 24871 - Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites

    Science.gov (United States)

    2011-05-03

    ... in the reimbursement ceilings). Title X requires DOE to reimburse eligible uranium and thorium... DEPARTMENT OF ENERGY Reimbursement for Costs of Remedial Action at Active Uranium and Thorium... reimbursement under Title X of the Energy Policy Act of 1992. DATES: In our Federal Register Notice of November...

  4. The Influences of Percent of Tributyl Phosphate and Ratio of Feed and Solvent on the Uranium-Thorium Extraction of Thorex Process

    International Nuclear Information System (INIS)

    Setyadji, Moch; Endang Susiantini

    2002-01-01

    The investigation of uranium and thorium extraction in water phase of thorex process first cycle using tributyl phosphate diluted in kerosine as extractant has been done. The one stage extractor was used. The effects of percent of tributyl phosphate and ratio of feed and solvent on the extraction efficiency and distribution coefficients of uranium and thorium were studied. The result of experiment showed that percent of tributyl phosphate and ratio of feed and solvent very influence on the extraction efficiency and distribution coefficients of uranium and thorium. The best results were reached at about 55% of tributyl phosphate and ratio of feed and solvent was 1:3. The extraction efficiencies of uranium and thorium and distribution coefficients of uranium and thorium at the condition above were 90% , 90.4% , 9.0 and 9.4. (author)

  5. Effect of hydrocarbon radical length of fatty acid collectors on flotation separation process of thorium ions

    International Nuclear Information System (INIS)

    Skrylev, L.D.; Perlova, O.V.; Sazonova, V.F.

    1991-01-01

    It is shown experimentally that the degree of flotation separation of thorium ions collected by their means increases firstly (potassium laurate), then decreases (potassium tridecanate) and after that increases again (potassium palminate) when increasing the length of the hydrocarbon radical of potassium soaps of saturated fatty acids. The first increase of the collector efficiency is due to the decrease of solubility of thorium-containing sublates, and drop and further increase is due to the change in colloidchemical properties of sublates

  6. Shielding evaluation of the Thorium Lean Raffinate (TLR) waste treatment system at Waste Immobilisation Plant, Trombay

    International Nuclear Information System (INIS)

    Bhosale, Nitin A.; Deepa, A.K.; Jakhete, A.P.; Gopalakrishnan, R.K.; Prasad, S.K.; Gangadharan, Anand; Singh, Neelima

    2012-01-01

    Thoria rods irradiated in research reactors were reprocessed for 233 U recovery and resulted in 9 m 3 of acidic Th-bearing raffinate waste. A two step treatment system was planned to treat the raffinate waste. The first step was the generation of thorium lean raffinate waste (TLR) after separation of thorium and the second step was the separation of residual radioactivity and conditioning planned at WIP. The beta activity in the TLR waste is around 50 mCi/i having 137 Cs, 90 Sr and 125 Sb as its main constituents. Shielding calculations were carried out for the various stages of the treatment system at Area-61 of WIP, Trombay. Dose rate evaluations at each step of the treatment system were evaluated to keep the personnel exposure during campaign, ALARA. The work set the base for the shielding design of the treatment system and for the estimation of the man-rem budgeting during commissioning of the system

  7. Estimation of thorium lung burden in mineral separation plant workers by thoron-in-breath measurements

    International Nuclear Information System (INIS)

    Radhakrishnan, Sujata; Sreekumar, K.; Tripathi, R.M.; Puranik, V.D.; Selvan, Esai

    2010-01-01

    The Minerals Separation Plant (MSP) of M/s Indian Rare Earths Ltd. (IREL) at Manavalakurichi in Tamil Nadu is engaged in the processing of beach sands to separate ilmenite, monazite, rutile, sillimanite, garnet, and zircon. The present study has been carried out on nearly 200 workers of the mineral separation plant who are chronically exposed to the radiation hazards. Measurement of thoron in the exhaled breath of the worker is an indirect method of estimating the body burden with regard to Th

  8. The development of the production process for the thorium/uranium dicarbide fuel kernels for the first charge of the Dragon Reactor

    International Nuclear Information System (INIS)

    Burnett, R.C.; Hankart, L.J.; Horsley, G.W.

    1965-05-01

    The development of methods of producing spheroidal sintered porous kernels of hyperstoichiometric thorium/uranium dicarbide solid solution from thorium/uranium monocarbide/carbon and thoria/urania/carbon powder mixes is described. The work has involved study of (i) Methods of preparing green kernels from UC/Th/C powder mixes using the rotary sieve technique. (ii) Methods of producing green kernels from UO2/Th02/C powder mixes using the planetary mill technique. (iii) The conversion by appropriate heat treatment of green kernels produced by both routes to sintered porous kernels of thorium/uranium carbide. (iv) The efficiency of the processes. (author)

  9. Criticality prevention specifications thorium--uranium-233 separations in the Purex Plant

    International Nuclear Information System (INIS)

    Matheison, W.E.; Oberg, G.C.; Ritter, G.L.

    1970-01-01

    The specifications in this document define the limits or restrictions required to maintain an acceptably low probability of the occurrence of a nuclear chain reaction in the Purex Plant while processing irradiated thoria targets. These criticality prevention specifications do not stipulate the system, procedures, or mechanisms to permit operation within the limits or restrictions

  10. Thorium utilization

    Energy Technology Data Exchange (ETDEWEB)

    Trauger, D B [Oak Ridge National Lab., TN (USA)

    1978-01-01

    Some of the factors that provide incentive for the utilization of thorium in specific reactor types are explored and the constraints that stand in the way are pointed out. The properties of thorium and derived fuels are discussed, and test and reactor operating experience is reviewed. In addition, symbiotic systems of breeder and converter reactor are suggested as being particularly attractive systems for energy production. Throughout the discussion, the High-Temperature Gas-Cooled Reactor and Molten Salt Reactor are treated in some detail because they have been developed primarily for use with thorium fuel cycles.

  11. Gas Turbine Energy Conversion Systems for Nuclear Power Plants Applicable to LiFTR Liquid Fluoride Thorium Reactor Technology

    Science.gov (United States)

    Juhasz, Albert J.

    2014-01-01

    This panel plans to cover thermal energy and electric power production issues facing our nation and the world over the next decades, with relevant technologies ranging from near term to mid-and far term.Although the main focus will be on ground based plants to provide baseload electric power, energy conversion systems (ECS) for space are also included, with solar- or nuclear energy sources for output power levels ranging tens of Watts to kilo-Watts for unmanned spacecraft, and eventual mega-Watts for lunar outposts and planetary surface colonies. Implications of these technologies on future terrestrial energy systems, combined with advanced fracking, are touched upon.Thorium based reactors, and nuclear fusion along with suitable gas turbine energy conversion systems (ECS) will also be considered by the panelists. The characteristics of the above mentioned ECS will be described, both in terms of their overall energy utilization effectiveness and also with regard to climactic effects due to exhaust emissions.

  12. 77 FR 3460 - Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites

    Science.gov (United States)

    2012-01-24

    ... available funding, the approved claim amounts will be reimbursed on a prorated basis. All reimbursements are...., statutory increases in the reimbursement ceilings). Title X requires DOE to reimburse eligible uranium and... DEPARTMENT OF ENERGY Reimbursement for Costs of Remedial Action at Active Uranium and Thorium...

  13. Thorium fuel cycle management

    International Nuclear Information System (INIS)

    Zajac, R.; Darilek, P.; Breza, J.; Necas, V.

    2010-01-01

    In this presentation author deals with the thorium fuel cycle management. Description of the thorium fuels and thorium fuel cycle benefits and challenges as well as thorium fuel calculations performed by the computer code HELIOS are presented.

  14. Ferrous Metal Processing Plants

    Data.gov (United States)

    Department of Homeland Security — This map layer includes ferrous metal processing plants in the United States. The data represent commodities covered by the Minerals Information Team (MIT) of the...

  15. Nonferrous Metal Processing Plants

    Data.gov (United States)

    Department of Homeland Security — This map layer includes nonferrous metal processing plants in the United States. The data represent commodities covered by the Minerals Information Team (MIT) of the...

  16. Thorium-applications and handling

    International Nuclear Information System (INIS)

    Reichelt, A.

    1993-01-01

    The most important aspects concerning the natural occurrence and extraction of thorium are presented the topics covered are: natural isotopes, occurence in minerals, thorium-activity-content of naturally occuring materials, the resulting radiation exposure, extraction of thorium from ores, time-dependent activity after separation. The sources of radiation exposure due to Thorium, caused by human activity, can be divided into two categories, namely, those in which thorium is deliberately added to (consumer) products in order to improve their usefullness, and those in which the thorium is present accidentally and unwanted due to the naturally occuring thorium in the material used in the manufacturing processes. Some examples of such products and substances will be presented and results about their specific thorium activity will be discussed. Experimental data from a currently running research programme, will be presented, and will include results concerning the radiation occupational exposure due to phosphate fertilizers, thorium impregnated gas mantles and the use of thoriated TIG-Electrodes in arc welding. (orig.) [de

  17. Uptake of radionuclide thorium by twelve native plants grown in uranium mill tailings soils from south part of China

    International Nuclear Information System (INIS)

    Yan, Xun

    2016-01-01

    Highlights: • Screen dominant plants grown in uranium mill tailings soils. • Quantify the content of "2"3"2Th of soil samples from uranium mill tailings. • Quantify the transfer factor, bioconcentration factor and phytoremediation factor. • Screen out the plant species capable of remediating radionuclide contaminated soils. • Guide the reuse of study area in future. - Abstract: The concentrations of thorium ("2"3"2Th) in soil from a uranium mill tailings repository in South China were analyzed. The results showed that all the soil samples were acidic and the concentrations of "2"3"2Th in all the soil samples were more than the natural radionuclide content in soil of China. Through the field investigation, twelve kinds of dominant plants were discovered. The total quantity of "2"3"2Th in the whole plant is highest in rice flat sedge. We also found that Miscanthus floridulus has the greatest transfer factor (TF) for "2"3"2Th, rice flat sedge has the greatest bioconcentration factor (BF) for "2"3"2Th. At the mean time, M. floridulus has the greatest phytoremediation factor (PF) for "2"3"2Th. On the basis of the above conclusions and the definition for hyperaccumulator, rice flat sedge and M. floridulus could be the candidates of phytoremediation for radionuclide "2"3"2Th in the soil.

  18. Uptake of radionuclide thorium by twelve native plants grown in uranium mill tailings soils from south part of China

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Xun, E-mail: m13836295186@163.com

    2016-08-01

    Highlights: • Screen dominant plants grown in uranium mill tailings soils. • Quantify the content of {sup 232}Th of soil samples from uranium mill tailings. • Quantify the transfer factor, bioconcentration factor and phytoremediation factor. • Screen out the plant species capable of remediating radionuclide contaminated soils. • Guide the reuse of study area in future. - Abstract: The concentrations of thorium ({sup 232}Th) in soil from a uranium mill tailings repository in South China were analyzed. The results showed that all the soil samples were acidic and the concentrations of {sup 232}Th in all the soil samples were more than the natural radionuclide content in soil of China. Through the field investigation, twelve kinds of dominant plants were discovered. The total quantity of {sup 232}Th in the whole plant is highest in rice flat sedge. We also found that Miscanthus floridulus has the greatest transfer factor (TF) for {sup 232}Th, rice flat sedge has the greatest bioconcentration factor (BF) for {sup 232}Th. At the mean time, M. floridulus has the greatest phytoremediation factor (PF) for {sup 232}Th. On the basis of the above conclusions and the definition for hyperaccumulator, rice flat sedge and M. floridulus could be the candidates of phytoremediation for radionuclide {sup 232}Th in the soil.

  19. Field test of plutonium and thorium contaminated clay soils from the Mound Site using the ACT*DE*CON Process

    International Nuclear Information System (INIS)

    Johnson, J.O.; Swift, N.A.; Church, R.H.; Neff, R.A.

    1998-01-01

    A treatability test was run during the summer and fall of 1997 to demonstrate the effectiveness of ACT*DE*CON for removing plutonium and thorium from the clay soils around Mound. ACT*DE*CON is a proprietary solution patented by Selentec. The process utilized a highly selective dissolution of the contaminants by the use of a chemical wash. The pilot scale process involved pretreatment of the soil in an attrition scrubber with ACT*DE*CON solution. This blended solution was then passed through a counter-current extraction chamber where additional contact with ACT*DE*CON solution occurred, followed by a rinse cycle. During this process sand was added to aid contact of the solution with the soil particles. The sand is removed during the rinse step and reused. The chelating agent is separated from the contaminant and recycled back into the process, along with the reverse osmosis permeate. The resulting solution can be further treated to concentrate the contaminant. Three different types of environmental soils were tested -- plutonium and thorium contaminated soils with the natural clay content, and plutonium contaminated soils with a high percentage of fine clay particles. The goal of these tests was to reduce the plutonium levels from several hundreds of pCi/g to between 25 and 75 pCi/g and the thorium from a couple hundred pCi/g to less than 5 pCi/g. The results of these four tests are presented along with a discussion of the operating parameters and the lessons learned relating to full scale implementation at Mound as well as other potential applications of this process

  20. Dynamic Analysis of the Thorium Fuel Cycle in CANDU Reactors

    International Nuclear Information System (INIS)

    Jeong, Chang Joon; Park, Chang Je

    2006-02-01

    The thorium fuel recycle scenarios through the Canada deuterium uranium (CANDU) reactor have been analyzed for two types of thorium fuel: homogeneous ThO 2 UO 2 and ThO 2 UO 2 -DUPIC fuels. The recycling is performed through the dry process fuel technology which has a proliferation resistance. For the once-through fuel cycle model, the existing nuclear power plant construction plan was considered up to 2016, while the nuclear demand growth rate from the year 2016 was assumed to be 0%. After setting up the once-through fuel cycle model, the thorium fuel CANDU reactor was modeled to investigate the fuel cycle parameters. In this analysis, the spent fuel inventory as well as the amount of plutonium, minor actinides and fission products of the multiple recycling fuel cycle were estimated and compared to those of the once-through fuel cycle. From the analysis results, it was found that the closed or partially closed thorium fuel cycle can be constructed through the dry process technology. Also, it is known that both the homogeneous and heterogeneous thorium fuel cycles can reduce the SF accumulation and save the natural uranium resource compared with the once-through cycle. From the material balance view point, the heterogeneous thorium fuel cycle seems to be more feasible. It is recommended, however, the economic analysis should be performed in future

  1. Dynamic Analysis of the Thorium Fuel Cycle in CANDU Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Chang Joon; Park, Chang Je

    2006-02-15

    The thorium fuel recycle scenarios through the Canada deuterium uranium (CANDU) reactor have been analyzed for two types of thorium fuel: homogeneous ThO{sub 2}UO{sub 2} and ThO{sub 2}UO{sub 2}-DUPIC fuels. The recycling is performed through the dry process fuel technology which has a proliferation resistance. For the once-through fuel cycle model, the existing nuclear power plant construction plan was considered up to 2016, while the nuclear demand growth rate from the year 2016 was assumed to be 0%. After setting up the once-through fuel cycle model, the thorium fuel CANDU reactor was modeled to investigate the fuel cycle parameters. In this analysis, the spent fuel inventory as well as the amount of plutonium, minor actinides and fission products of the multiple recycling fuel cycle were estimated and compared to those of the once-through fuel cycle. From the analysis results, it was found that the closed or partially closed thorium fuel cycle can be constructed through the dry process technology. Also, it is known that both the homogeneous and heterogeneous thorium fuel cycles can reduce the SF accumulation and save the natural uranium resource compared with the once-through cycle. From the material balance view point, the heterogeneous thorium fuel cycle seems to be more feasible. It is recommended, however, the economic analysis should be performed in future.

  2. Research and development of thorium fuel cycle

    International Nuclear Information System (INIS)

    Oishi, Jun.

    1994-01-01

    Nuclear properties of thorium are summarized and present status of research and development of the use of thorium as nuclear fuel is reviewed. Thorium may be used for nuclear fuel in forms of metal, oxide, carbide and nitride independently, alloy with uranium or plutonium or mixture of the compound. Their use in reactors is described. The reprocessing of the spent oxide fuel in thorium fuel cycle is called the thorex process and similar to the purex process. A concept of a molten salt fuel reactor and chemical processing of the molten salt fuel are explained. The required future research on thorium fuel cycle is commented briefly. (T.H.)

  3. Inhalation exposures at a thorium refinery

    International Nuclear Information System (INIS)

    Mausner, L.F.

    1982-01-01

    There is a current interest in the metabolism and health effects of thorium due to its potential use in the 232 Th - 233 U nuclear fuel cycle. The airborne concentrations of thorium, thoron daughters and rare earths in a plant which produced thorium and rare earth chemicals from 1932 to 1973 were calculated from past records of alpha counting and air filter samples. This analysis showed that high airborne concentrations of 232 Th, 220 Rn, 212 Pb, 212 Bi and rare earth elements were sometimes reached during plant operations. Limited measurements on autopsy samples of former employees of the plant showed increased tissue concentrations of thorium and rare earths. (U.K.)

  4. Thorium in nuclear fuel

    International Nuclear Information System (INIS)

    Stankevicius, Alejandro

    2012-01-01

    We revise the advantages and possible problems on the use of thorium as a nuclear fuel instead of uranium. The following aspects are considered: 1) In the world there are three times more thorium than uranium 2) In spite that thorium in his natural form it is not a fisil, under neutron irradiation, is possible to transform it to uranium 233, a fisil of a high quality. 3) His ceramic oxides properties are superior to uranium or plutonium oxides. 4) During the irradiation the U 233 due to n,2n reaction produce small quantities of U 232 and his decay daughters' bismuth 212 and thallium 208 witch are strong gamma source. In turn thorium 228 and uranium 232 became, in time anti-proliferate due to there radiation intensity. 5) As it is described in here and experiments done in several countries reactors PHWR can be adapted to the use of thorium as a fuel element 6) As a problem we should mentioned that the different steps in the process must be done under strong radiation shielding and using only automatized equipment s (author)

  5. Investigation of thorium hydroxotrifluoroacetates

    International Nuclear Information System (INIS)

    Andryushin, V.G.; Samatov, A.V.; Chuklinov, R.N.; Shmidt, V.S.

    1984-01-01

    The precipitation process of thorium hydroxotrifluoroacetates in the Th(NO 3 ) 4 -HNO 3 -CF 3 COOH-NH 4 OH-H 2 O system in the pH range from 0.1 to 8.6 at a 100 g/l thorium concentration in it has been investigated. The curve of the pH dependence of the main thorium salts solubility in the pH=4.4 range exhibits a local maximum, the position of the latter being in complete accordance with its earlier established relation to the parameter of the ligand anion nucleophility. The composition of isolated hydroxotrifluoroacetate hydrates corresponds to the generic formula Th(OH)sub(x)(CFsub(3)COO)sub(4-x)xnHsub(2)O, where 3.0 >= x >= 1.5, and n=1.0-6.0. The density of the crystals obtained is measured and the thermal stability is studied. It is established, that, for the thorium hydroxotrifluoroacetate hydrates, the same general regularities in the effect of degree of hydrolysis and hydration on the position of decomposition temperature effects and on the density of compounds hold, as has been previously found in studying thorium- and plutonium hydroxosalts

  6. Power plant process computer

    International Nuclear Information System (INIS)

    Koch, R.

    1982-01-01

    The concept of instrumentation and control in nuclear power plants incorporates the use of process computers for tasks which are on-line in respect to real-time requirements but not closed-loop in respect to closed-loop control. The general scope of tasks is: - alarm annunciation on CRT's - data logging - data recording for post trip reviews and plant behaviour analysis - nuclear data computation - graphic displays. Process computers are used additionally for dedicated tasks such as the aeroball measuring system, the turbine stress evaluator. Further applications are personal dose supervision and access monitoring. (orig.)

  7. Comparison studies adsorption of thorium and uranium on pure clay minerals and local Malaysian soil sediments

    International Nuclear Information System (INIS)

    Syed, H.S.

    1999-01-01

    Adsorption studies of thorium and uranium radionuclides on 9 different pure clay minerals and 4 local Malaysian soil sediments were conducted. Solution containing dissolved thorium and uranium at pH 4.90 was prepared from concentrate sludges from a long term storage facility at a local mineral processing plant. The sludges are considered as low level radioactive wastes. The results indicated that the 9 clay minerals adsorbed more uranium than thorium at pH ranges from 3.74 to 5.74. Two local Malaysian soils were observed to adsorb relatively high concentration of both radionuclides at pH 3.79 to 3.91. The adsorption value 23.27 to 27.04 ppm for uranium and 33.1 to 50.18 ppm for thorium indicated that both soil sediments can be considered as potential enhanced barrier material for sites disposing conditioned wastes containing uranium and thorium. (author)

  8. Synthesis of uranium and thorium dioxides by Complex Sol-Gel Processes (CSGP). Synthesis of uranium oxides by Complex Sol-Gel Processes (CSGP)

    International Nuclear Information System (INIS)

    Deptula, A.; Brykala, M.; Lada, W.; Olczak, T.; Wawszczak, D.; Chmielewski, A.G.; Modolo, G.; Daniels, H.

    2010-01-01

    In the Institute of Nuclear Chemistry and Technology (INCT), a new method of synthesis of uranium and thorium dioxides by original variant of sol-gel method - Complex Sol-Gel Process (CSGP), has been elaborated. The main modification step is the formation of nitrate-ascorbate sols from components alkalized by aqueous ammonia. Those sols were gelled into: - irregularly agglomerates by evaporation of water; - medium sized microspheres (diameter <150) by IChTJ variant of sol-gel processes by water extraction from drops of emulsion sols in 2-ethylhexanol-1 by this solvent. Uranium dioxide was obtained by a reduction of gels with hydrogen at temperatures >700 deg. C, while thorium dioxide by a simple calcination in the air atmosphere. (authors)

  9. Recovery of radiogenic lead-208 from a residue of thorium and rare earths obtained during the operation of a thorium purification pilot plant; Separacao e recuperacao de chumbo-208 dos residuos de torio terras raras gerados na unidade piloto de purificacao de nitrato de torio

    Energy Technology Data Exchange (ETDEWEB)

    Seneda, Jose Antonio

    2006-07-01

    Brazil has a long tradition in thorium technology, from mineral dressing (monazite) to the nuclear grade thorium compounds. The estimate reserves are 1200,000. ton of ThO{sub 2}. As a consequence from the work of thorium purification pilot plant at Instituto de Pesquisas Energeticas e Nucleares-CNEN/IPEN-SP, about 25 ton of a sludge containing thorium and rare earths was accumulated. It comes as a raffinate and washing solutions from thorium solvent extraction. This sludge, a crude hydroxide named RETOTER contains thorium, rare earths and minor impurities including the radiogenic lead-208, with abundance 88.34 %. This work discusses the results of the studies and main parameters for its recovery by anionic ion exchange technique in the hydrochloric system. The isotope abundance of this lead was analyzed by high resolution mass spectrometer (ICPMS) and thermoionic mass spectrometer (TIMS) and the data was used to calculate the thermal neutron capture cross section. The value of {sigma}{gamma}{sup 0} = 14.6{+-}0.7 mb was found, quite different from the {sigma}{gamma}{sup 0} = 174.2 {+-} 7.0 mb measure cross section for the natural lead. Preliminary study for the thorium and rare earths separation and recovery was discussed as well. (author)

  10. Acid pressure leaching of a concentrate containing uranium, thorium and rare earth elements

    International Nuclear Information System (INIS)

    Lan Xinghua; Peng Ruqing.

    1987-01-01

    The acid pressure leaching of a concentrate containing rinkolite for recovering uranium, thorium and rare earth elements is described. The laboratory and the pilot plant test results are given. Under the optimum leaching conditions, the recovery of uranium, thorium and rare earth elements are 82.9%, 86.0% and 88.3% respectively. These results show that the acid pressure leaching process is a effective process for treating the concentrate

  11. Transuranium processing plant

    International Nuclear Information System (INIS)

    King, L.J.

    1983-01-01

    The Transuranium Processing Plant (TRU) is a remotely operated, hot-cell, chemical processing facility of advanced design. The heart of TRU is a battery of nine heavily shielded process cells housed in a two-story building. Each cell, with its 54-inch-thick walls of a special high-density concrete, has enough shielding to stop the neutrons and gamma radiation from 1 gram of 252/sub Cf/ and associated fission products. Four cells contain chemical processing equipment, three contain equipment for the preparation and inspection of HFIR targets, and two cells are used for analytical chemistry operations. In addition, there are eight laboratories used for process development, for part of the process-control analyses, and for product finishing operations. Although the Transuranium Processing Plant was built for the purpose of recovering transuranium elements from targets irradiated in the High Flux Isotope Reactor (HFIR), it is also a highly versatile facility which has extensive provisions for changing and modifying equipment. Thus, it was a relatively simple matter to install a Solvent Extraction Test Facility (SETF) in one of the TRU chemical processing cells for use in the evaluation and demonstration of solvent extraction flowsheets for the recovery of fissile and fertile materials from irradiated reactor fuels. The equipment in the SETF has been designed for process development and demonstrations and the particular type of mixer-settler contactors was chosen because it is easy to observe and sample

  12. Study of treatment of a thorium and rare earths residue by extraction chromatography

    International Nuclear Information System (INIS)

    Zini, Josiane; Abrao, Alcidio; Carvalho, Fatima Maria Sequeira de; Freitas, Antonio Alves de; Scapin, Marcos Antonio

    2005-01-01

    In the 70's was established at IPEN the project of a thorium compounds purification pilot plant that had the goal of fulfilling the nuclear technology purity standards. The used method was the purification by extraction with solvents in pulsed columns. The thorium remaining in the organic phase was back extracted as thorium nitrate with a high degree of purity. Impurities, thorium non-extracted and practically all rare earths in aqueous phase of this chemical process were precipitated as hydroxide, generating a product containing thorium and rare earths, that was denominated RETOTER (residue of thorium and rare earths). This residue was accumulated and today there are 25 (twenty-five) metric tons of this by product stored in the safeguard storage shed at IPEN that must to be treated due to the radiation of the thorium and mainly his daughters. The average composition of this residue is, 68% in thorium oxide (ThO 2 ), 5% in rare earths oxides (R 2 O 3 ), 0,3% in uranium oxide (U 3 O 8 ) and common impurities such as phosphorus, iron, titanium, lead and sodium. In this work a new method is presented for separation and purification of thorium from this residue, obtaining a concentrate with high degree of purity for nuclear and non-nuclear use. This process will contribute to establish a decreasing of residue volumes, to have a mind to the minimization of environmental impacts, the reduction of worker's exposition and reduction of the storage costs. In this process the separation and purification of uranium and thorium is done by chromatography extraction, being used polymeric resins, that are previously functionalized with organic solvent (extractor agent). The effluent of this process is a concentrate of rare earths that can be reprocessed in a subsequent fractionating for to obtaining the individual fractions. (author)

  13. Process Experimental Pilot Plant

    International Nuclear Information System (INIS)

    Henze, H.

    1986-01-01

    The Process Experimental Pilot Plant (PREPP) at the Idaho National Engineering Laboratory (INEL) was built to convert transuranic contaminated solid waste into a form acceptable for disposal at the Waste Isolation Pilot Plant (WIPP), located near Carlsbad, New Mexico. There are about 2.0 million cubic ft of transuranic waste stored at the Transuranic Storage Area of the INEL's Radioactive Waste Management Complex (RWMC). The Stored Waste Examination Pilot Plant (SWEPP) located at the RWMC will examine this stored transuranic waste to determine if the waste is acceptable for direct shipment to and storage at WIPP, or if it requires shipment to PREPP for processing before shipment to WIPP. The PREPP process shreds the waste, incinerates the shredded waste, and cements (grouts) the shredded incinerated waste in new 55-gal drums. Unshreddable items are repackaged and returned to SWEPP. The process off-gas is cleaned prior to its discharge to the atmosphere, and complies with the effluent standards of the State of Idaho, EPA, and DOE. Waste liquid generated is used in the grouting operation

  14. Thorium Th

    International Nuclear Information System (INIS)

    Busev, A.I.; Tiptsova, V.G.; Ivanov, V.M.

    1978-01-01

    The basic methods for extracting thorium from monazites and determining it photometrically and complexometrically are described. Monazite is decomposed by fusion with sodium peroxide, then thorium and the totality of lanthanides are precipitated in the form of oxalates. After the oxalates have been broken down, thorium is determined photometrically with the aid of arsenazo 1, quercetin of 1-2(-pyridylazo)-resorcin. It takes 25 to 30 minutes to photometrically determine Th in monazites with the aid of arsenazo 2 (error: 3 to 5%). Arsenazo 2 is recommended for analysis of monazites containing 20 to 30% of lanthanides. Arsenazo 3 permits determining Th in zircon and in Nb-containing materials. In this case, the determination is possible in strongly acidic solutions, the ratio of arsenazo 3 to Th being 7.5:1. Arsenazo 3 can also be used in determining trace amounts of Th (1x10 -5 to 1x10 -4 %) in rocks, as well as in extraction-photometric determination of Th traces. The dyed compound of Th with arsenazo 3 is extracted with isoamyl alcohol in the presence of diphenylguanidinium chloride and monochloroacetic acid. The method permits determining Th at 1:5x10 8 (0.002 g/ml) dilution. Also described is the iodate-complexometric method for determining Th

  15. Candu reactors with thorium fuel cycles

    International Nuclear Information System (INIS)

    Hopwood, J.M.; Fehrenbach, P.; Duffey, R.; Kuran, S.; Ivanco, M.; Dyck, G.R.; Chan, P.S.W.; Tyagi, A.K.; Mancuso, C.

    2006-01-01

    Over the last decade and a half AECL has established a strong record of delivering CANDU 6 nuclear power plants on time and at budget. Inherently flexible features of the CANDU type reactors, such as on-power fuelling, high neutron economy, fuel channel based heat transport system, simple fuel bundle configuration, two independent shut down systems, a cool moderator and a defence-in-depth based safety philosophy provides an evolutionary path to further improvements in design. The immediate milestone on this path is the Advanced CANDU ReactorTM** (ACRTM**), in the form of the ACR-1000TM**. This effort is being followed by the Super Critical Water Reactor (SCWR) design that will allow water-cooled reactors to attain high efficiencies by increasing the coolant temperature above 550 0 C. Adaptability of the CANDU design to different fuel cycles is another technology advantage that offers an additional avenue for design evolution. Thorium is one of the potential fuels for future reactors due to relative abundance, neutronics advantage as a fertile material in thermal reactors and proliferation resistance. The Thorium fuel cycle is also of interest to China, India, and Turkey due to local abundance that can ensure sustainable energy independence over the long term. AECL has performed an assessment of both CANDU 6 and ACR-1000 designs to identify systems, components, safety features and operational processes that may need to be modified to replace the NU or SEU fuel cycles with one based on Thorium. The paper reviews some of these requirements and the associated practical design solutions. These modifications can either be incorporated into the design prior to construction or, for currently operational reactors, during a refurbishment outage. In parallel with reactor modifications, various Thorium fuel cycles, either based on mixed bundles (homogeneous) or mixed channels (heterogeneous) have been assessed for technical and economic viability. Potential applications of a

  16. Recovery of thorium and uranium from monazite processing Liquor produced by INB/Caldas, M G, by solvent extraction

    International Nuclear Information System (INIS)

    Amaral, Janubia Cristina Braganca da Silva

    2006-01-01

    This work describes the study of thorium and uranium recovery from sulfuric liquor generated in chemical monazite treatment by solvent extraction technique. The sulfuric liquor was produced by Industries Nuclear of Brazil - INB, Caldas - Minas Gerais State. The study was carried out in two steps: in the first the process variable were investigated through discontinuous experiments; in the second, the parameters were optimized by continuous solvent extraction experiments. The influence of the following process variables was investigated: type and concentration of extracting agents, contact time between phases and aqueous/organic volumetric ratio. Extractants used in this study included: Primene J M-T, Primene 81-R, Alamine 336 and Aliquat 336. Thorium and uranium were simultaneously extracted by a mixture of Primene J M-T and Alamine 336, into Exxsol D-100. The stripping was carried out by hydrochloric acid (HCl) 2.0 mol/L. The study was carried out at room temperature. After selected the best process conditions, two continuous experiments of extraction and stripping were carried out. In the first experiment a mixture of 0.15 mol/L Primene J M-T and 0.05 mol/L Alamine 336 were used. The second experiment was carried out using 0.15 mol/L Primene J M-T and 0.15 mol/L Alamine 336. Four extraction stages and five stripping stages were used in both experiments. The first experiment showed a ThU 2 and U 3 O 8 content in loaded strip solution of 34.3 g/L and 1.49 g/L respectively and 0.10 g/L Th) 2 and 0.05 g/L U 3 O 8 in the raffinate. In the second experiment a loaded strip solution with 29.3 g/L ThO 2 and 0.94 g/L U 3 O 8 was obtained. In this experiment, the metals content in raffinate was less than 0.001 g/L, indicating a thorium recovery over 99.9% and uranium recovery of 99.4%. (author)

  17. Thorium, uranium and rare earth elements content in lanthanide concentrate (LC) and water leach purification (WLP) residue of Lynas advanced materials plant (LAMP)

    Science.gov (United States)

    AL-Areqi, Wadeeah M.; Majid, Amran Ab.; Sarmani, Sukiman

    2014-02-01

    Lynas Advanced Materials Plant (LAMP) has been licensed to produce the rare earths elements since early 2013 in Malaysia. LAMP processes lanthanide concentrate (LC) to extract rare earth elements and subsequently produce large volumes of water leach purification (WLP) residue containing naturally occurring radioactive material (NORM). This residue has been rising up the environmental issue because it was suspected to accumulate thorium with significant activity concentration and has been classified as radioactive residue. The aim of this study is to determine Th-232, U-238 and rare earth elements in lanthanide concentrate (LC) and water leach purification (WLP) residue collected from LAMP and to evaluate the potential radiological impacts of the WLP residue on the environment. Instrumental Neutron Activation Analysis and γ-spectrometry were used for determination of Th, U and rare earth elements concentrations. The results of this study found that the concentration of Th in LC was 1289.7 ± 129 ppm (5274.9 ± 527.6Bq/kg) whereas the Th and U concentrations in WLP were determined to be 1952.9±17.6 ppm (7987.4 ± 71.9 Bq/kg) and 17.2 ± 2.4 ppm respectively. The concentrations of Th and U in LC and WLP samples determined by γ- spectrometry were 1156 ppm (4728 ± 22 Bq/kg) & 18.8 ppm and 1763.2 ppm (7211.4 Bq/kg) &29.97 ppm respectively. This study showed that thorium concentrations were higher in WLP compare to LC. This study also indicate that WLP residue has high radioactivity of 232Th compared to Malaysian soil natural background (63 - 110 Bq/kg) and come under preview of Act 304 and regulations. In LC, the Ce and Nd concentrations determined by INAA were 13.2 ± 0.6% and 4.7 ± 0.1% respectively whereas the concentrations of La, Ce, Nd and Sm in WLP were 0.36 ± 0.04%, 1.6%, 0.22% and 0.06% respectively. This result showed that some amount of rare earth had not been extracted and remained in the WLP and may be considered to be reextracted.

  18. Thorium, uranium and rare earth elements content in lanthanide concentrate (LC) and water leach purification (WLP) residue of Lynas advanced materials plant (LAMP)

    International Nuclear Information System (INIS)

    AL-Areqi, Wadeeah M.; Majid, Amran Ab.; Sarmani, Sukiman

    2014-01-01

    Lynas Advanced Materials Plant (LAMP) has been licensed to produce the rare earths elements since early 2013 in Malaysia. LAMP processes lanthanide concentrate (LC) to extract rare earth elements and subsequently produce large volumes of water leach purification (WLP) residue containing naturally occurring radioactive material (NORM). This residue has been rising up the environmental issue because it was suspected to accumulate thorium with significant activity concentration and has been classified as radioactive residue. The aim of this study is to determine Th-232, U-238 and rare earth elements in lanthanide concentrate (LC) and water leach purification (WLP) residue collected from LAMP and to evaluate the potential radiological impacts of the WLP residue on the environment. Instrumental Neutron Activation Analysis and γ-spectrometry were used for determination of Th, U and rare earth elements concentrations. The results of this study found that the concentration of Th in LC was 1289.7 ± 129 ppm (5274.9 ± 527.6Bq/kg) whereas the Th and U concentrations in WLP were determined to be 1952.9±17.6 ppm (7987.4 ± 71.9 Bq/kg) and 17.2 ± 2.4 ppm respectively. The concentrations of Th and U in LC and WLP samples determined by γ- spectrometry were 1156 ppm (4728 ± 22 Bq/kg) and 18.8 ppm and 1763.2 ppm (7211.4 Bq/kg) and 29.97 ppm respectively. This study showed that thorium concentrations were higher in WLP compare to LC. This study also indicate that WLP residue has high radioactivity of 232 Th compared to Malaysian soil natural background (63 - 110 Bq/kg) and come under preview of Act 304 and regulations. In LC, the Ce and Nd concentrations determined by INAA were 13.2 ± 0.6% and 4.7 ± 0.1% respectively whereas the concentrations of La, Ce, Nd and Sm in WLP were 0.36 ± 0.04%, 1.6%, 0.22% and 0.06% respectively. This result showed that some amount of rare earth had not been extracted and remained in the WLP and may be considered to be reextracted

  19. Thorium, Uranium and Rare Earth Elements content in lanthanide concentrate (LC) and water leach purification (WLP) residue of Lynas Advanced Materials Plant (LAMP)

    International Nuclear Information System (INIS)

    Al-Areqi, W.M.; Amran Abdul Majid; Sukiman Sarmani

    2013-01-01

    Full-text: Lynas Advanced Materials Plant (LAMP) has been licensed to produce the rare earths elements since early 2013 in Malaysia. LAMP processes lanthanide concentrate (LC) to extract rare earth elements and subsequently produce large volumes of water leach purification (WLP) residue containing naturally occurring radioactive material (NORM). This residue has been rising up the environmental issue because it was suspected to accumulate thorium with significant activity concentration and has been classified as radioactive residue. The aim of this study is to determine Th-232, U-238 and rare earth elements in lanthanide concentrate (LC) and water leach purification (WLP) residue collected from LAMP and to evaluate the potential radiological impacts of the WLP residue on the environment. Instrumental Neutron Activation Analysis and γ-spectrometry were used for determination of Th, U and rare earth elements concentrations. The results of this study found that the concentration of Th in LC was 1289.7 ± 129 ppm (5274.9 ± 527.6 Bq/ kg) whereas the Th and U concentrations in WLP were determined to be 1952.9 ± 17.6 ppm (7987.4 ± 71.9 Bq/ kg) and 17.2 ± 2.4 ppm respectively. The concentrations of Th and U in LC and WLP samples determined by γ- spectrometry were 1156 ppm (4728 ± 22 Bq/ kg) and 18.8 ppm and 1763.2 ppm (7211.4 Bq/ kg) and 29.97 ppm respectively. This study showed that thorium concentrations were higher in WLP compare to LC. This study also indicate that WLP residue has high radioactivity of 232 Th compared to Malaysian soil natural background (63 - 110 Bq/ kg) and come under preview of Act 304 and regulations. In LC, the Ce and Nd concentrations determined by INAA were 13.2 ± 0.6 % and 4.7 ± 0.1 % respectively whereas the concentrations of La, Ce, Nd and Sm in WLP were 0.36 ± 0.04 %, 1.6 %, 0.22 % and 0.06 % respectively. This result showed that some amount of rare earth had not been extracted and remained in the WLP and may be considered to be re

  20. Thorium, uranium and rare earth elements content in lanthanide concentrate (LC) and water leach purification (WLP) residue of Lynas advanced materials plant (LAMP)

    Energy Technology Data Exchange (ETDEWEB)

    AL-Areqi, Wadeeah M., E-mail: walareqi@yahoo.com; Majid, Amran Ab., E-mail: walareqi@yahoo.com; Sarmani, Sukiman, E-mail: walareqi@yahoo.com [Nuclear Science Programme, School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi (Malaysia)

    2014-02-12

    Lynas Advanced Materials Plant (LAMP) has been licensed to produce the rare earths elements since early 2013 in Malaysia. LAMP processes lanthanide concentrate (LC) to extract rare earth elements and subsequently produce large volumes of water leach purification (WLP) residue containing naturally occurring radioactive material (NORM). This residue has been rising up the environmental issue because it was suspected to accumulate thorium with significant activity concentration and has been classified as radioactive residue. The aim of this study is to determine Th-232, U-238 and rare earth elements in lanthanide concentrate (LC) and water leach purification (WLP) residue collected from LAMP and to evaluate the potential radiological impacts of the WLP residue on the environment. Instrumental Neutron Activation Analysis and γ-spectrometry were used for determination of Th, U and rare earth elements concentrations. The results of this study found that the concentration of Th in LC was 1289.7 ± 129 ppm (5274.9 ± 527.6Bq/kg) whereas the Th and U concentrations in WLP were determined to be 1952.9±17.6 ppm (7987.4 ± 71.9 Bq/kg) and 17.2 ± 2.4 ppm respectively. The concentrations of Th and U in LC and WLP samples determined by γ- spectrometry were 1156 ppm (4728 ± 22 Bq/kg) and 18.8 ppm and 1763.2 ppm (7211.4 Bq/kg) and 29.97 ppm respectively. This study showed that thorium concentrations were higher in WLP compare to LC. This study also indicate that WLP residue has high radioactivity of {sup 232}Th compared to Malaysian soil natural background (63 - 110 Bq/kg) and come under preview of Act 304 and regulations. In LC, the Ce and Nd concentrations determined by INAA were 13.2 ± 0.6% and 4.7 ± 0.1% respectively whereas the concentrations of La, Ce, Nd and Sm in WLP were 0.36 ± 0.04%, 1.6%, 0.22% and 0.06% respectively. This result showed that some amount of rare earth had not been extracted and remained in the WLP and may be considered to be reextracted.

  1. Thorium-U Recycle Facility (7930)

    Data.gov (United States)

    Federal Laboratory Consortium — The Thorium-U Recycle Facility (7930), along with the Transuranic Processing Facility (7920). comprise the Radiochemical Engineering Development Complex. 7930 is a...

  2. Thorium nuclear fuel cycle technology

    International Nuclear Information System (INIS)

    Eom, Tae Yoon; Do, Jae Bum; Choi, Yoon Dong; Park, Kyoung Kyum; Choi, In Kyu; Lee, Jae Won; Song, Woong Sup; Kim, Heong Woo

    1998-03-01

    Since thorium produces relatively small amount of TRU elements after irradiation in the reactor, it is considered one of possible media to mix with the elements to be transmuted. Both solid and molten-salt thorium fuel cycles were investigated. Transmutation concepts being studied involved fast breeder reactor, accelerator-driven subcritical reactor, and energy amplifier with thorium. Long-lived radionuclides, especially TRU elements, could be separated from spent fuel by a pyrochemical process which is evaluated to be proliferation resistance. Pyrochemical processes of IFR, MSRE and ATW were reviewed and evaluated in detail, regarding technological feasibility, compatibility of thorium with TRU, proliferation resistance, their economy and safety. (author). 26 refs., 22 figs

  3. Adaptive responses on chromosome aberration and DNA breakage of peripheral lymphocytes from workers exposed to thorium and rare earth mixed dust in Baotou steel plant

    International Nuclear Information System (INIS)

    Liu Qingjie; Feng Jiangbing; Lu Xue; Chen Deqing; Lv Huimin; Su Xu; Liu Yufei; Jia Kejun

    2008-01-01

    Objective: To explore if the occupational exposure to low dose thorium could induce adaptive response in peripheral lymphocytes. Methods: 40 individuals, who exposed to thorium and rare earth mixed dust (exposure group) or control in Baotou Steel Plant, were selected, and chromosome aberrations were analyzed. Then the peripheral blood samples were irradiated in vitro with 2 Gy 60 Co γ-rays, and unstable chromosome aberration or DNA stand breakage analysis using single cell gel electrophoresis was performed. Results: The dicentrics before 2 Gy exposure in exposure group was higher than that in control (P>0.05). But the dicentrics after 2 Gy exposure in exposure group was lower than that in control, but not significantly (P >0.05). The tricentrics in exposure group was significantly lower than that in control (U=3.1622, 0.001< P<0.002). The DNA strand breakage in control group was significantly higher than that in exposure group (t=25, P<0.001). Conclusions: Occupational exposure to low dose thorium could induce the adaptive response on chromosome aberration and DNA strand breakage in peripheral lymphocytes. (authors)

  4. Uranium, thorium, lead, lantanoids and yttrium in some plants growing on granitic and radioactive rocks

    Energy Technology Data Exchange (ETDEWEB)

    Yliruokanen, I [Helsinki Univ. of Technology, Otaniemi (Finland). Dept. of Chemistry

    1975-01-01

    Spark source mass spectrometry with electrical detection was used for the determination of trace element contents in the ash of 172 plants comprising 21 lichens, 42 mosses, 78 dwarf shrubs and 31 trees. The highest contents found in single samples were 2800 ppm U in one moss, 20 ppm Th in one moss and one lichen, 1200 to 1000 ppm Pb in lichens and mosses and in one Calluna vulgaris, 110 to 100 ppm Y and La in some lichens and mosses and 350 ppm Ce in one moss; the mean contents were usually significantly lower. No anomalies were found in the lanthanoid distribution in these plants and the influence of uranium and lanthanoid mineralizations was detectable only in the immediate vicinity of mineralized spots.

  5. Plant extraction process

    DEFF Research Database (Denmark)

    2006-01-01

    A method for producing a plant extract comprises incubating a plant material with an enzyme composition comprising a lipolytic enzyme.......A method for producing a plant extract comprises incubating a plant material with an enzyme composition comprising a lipolytic enzyme....

  6. Hydriding of metallic thorium

    International Nuclear Information System (INIS)

    Miyake, Masanobu; Katsura, Masahiro; Matsuki, Yuichi; Uno, Masayoshi

    1983-01-01

    Powdered thorium is usually prepared through a combination of hydriding and dehydriding processes of metallic thorium in massive form, in which the hydriding process consists of two steps: the formation of ThH 2 , and the formation of Th 4 H 15 . However, little has yet been known as to on what stage of hydriding process the pulverization takes place. It is found in the present study that the formation of Th 4 H 15 by the reaction of ThH 2 with H 2 is responsible for pulverization. Temperature of 70 deg C adopted in this work for the reaction of formation Th 4 H 15 seems to be much more effective for production of powdered thorium than 200 - 300 deg C in the literature. The pressure-composition-temperature relationships for Th-H system are determined at 200, 300, 350, and 800 deg C. From these results, a tentative equilibrium phase diagram for the Th-H system is proposed, attention being focused on the two-phase region of ThH 2 and Th 4 H 15 . Pulverization process is discussed in terms of the tentative phase diagram. (author)

  7. Studies on the preparation of thorium metal sponge from thorium oxalate

    International Nuclear Information System (INIS)

    Vijay, P.L.; Sehra, J.C.; Sundaram, C.V.; Gurumurthy, K.R.; Raghavan, R.V.

    1978-01-01

    The results of investigations carried out on the production of high purity thorium metal sponge, starting with thorium oxalate are presented. The flow sheet includes chlorination of thorium oxalate, purification of raw thorium tetrachloride, magnesium reduction of anhydrous thorium tetrachloride, slag metal separation, vacuum distillation for removal of residual MgCl 2 and excess magnesium, and consolidation of the metal sponge. Studies have been carried out to investigate the optimum chlorination efficiency and chlorine utilization attainable using different chlorinating agents, and to compare the quality of the sponge obtained with single and double distilled chloride. The overall process efficiency under optimum conditions was 81%. The thorium metal button, prepared from the sponge by arc-melting, analysed : O 2 - 847, N 2 - 20, C - 179, Mg - 100, Fe - 49, Ni<50, Al - 11, Cr - 7 (expressed in parts per million parts of thorium). The button could be further purified by electron beam melting to improve its ductility. (author)

  8. Equipment for the handling of thorium materials

    International Nuclear Information System (INIS)

    Heisler, S.W. Jr.; Mihalovich, G.S.

    1988-01-01

    The Feed Materials Production Center (FMPC) is the United States Department of Energy's storage facility for thorium. FMPC thorium handling and overpacking projects ensure the continued safe handling and storage of the thorium inventory until final disposition of the materials is determined and implemented. The handling and overpacking of the thorium materials requires the design of a system that utilizes remote handling and overpacking equipment not currently utilized at the FMPC in the handling of uranium materials. The use of remote equipment significantly reduces radiation exposure to personnel during the handling and overpacking efforts. The design system combines existing technologies from the nuclear industry, the materials processing and handling industry and the mining industry. The designed system consists of a modified fork lift truck for the transport of thorium containers, automated equipment for material identification and inventory control, and remote handling and overpacking equipment for material identification and inventory control, and remote handling and overpacking equipment for repackaging of the thorium materials

  9. Thorium-232

    International Nuclear Information System (INIS)

    Ammerich, Marc; Frot, Patricia; Gambini, Denis-Jean; Gauron, Christine; Moureaux, Patrick; Herbelet, Gilbert; Lahaye, Thierry; Pihet, Pascal; Rannou, Alain; Vial, Eric

    2013-12-01

    This sheet belongs to a collection which relates to the use of radionuclides essentially in unsealed sources. Its goal is to gather on a single document the most relevant information as well as the best prevention practices to be implemented. These sheets are made for the persons in charge of radiation protection: users, radioprotection-skill persons, labor physicians. Each sheet treats of: 1 - the radio-physical and biological properties; 2 - the main uses; 3 - the dosimetric parameters; 4 - the measurement; 5 - the protection means; 6 - the areas delimitation and monitoring; 7 - the personnel classification, training and monitoring; 8 - the effluents and wastes; 9 - the authorization and declaration administrative procedures; 10 - the transport; and 11 - the right conduct to adopt in case of incident or accident. This sheet deals specifically with Thorium-232

  10. Production of thorium nitrate from uranothorianite ores

    International Nuclear Information System (INIS)

    Brodsky, M.; Sartorius, R.; Sousseuer, Y.

    1959-01-01

    The separation of thorium and uranium from uranothorianite ores, either by precipitation or solvent-extraction methods, are discussed, and an industrial process for the manufacture of thorium nitrate is described. Reprint of a paper published in 'Progress in Nuclear Energy' Series III, Vol. 2 - Process Chemistry, 1959, p. 68-76 [fr

  11. Measurement of thorium content in gas mantles produced in India

    Energy Technology Data Exchange (ETDEWEB)

    Gaur, P K [Bhabha Atomic Research Centre, Mumbai (India). Radiological Physics Div.; Chury, A J; Venkataraman, G [Bhabha Atomic Research Centre, Mumbai (India). Radiation Protection Services Div.

    1994-04-01

    Incandescent gas mantles, processed with thorium nitrate, were monitored for thorium content, using a 2 inch thick Nal(Tl) detector and detecting medium energy gamma radiations emitted by thorium daughters. Thirty different brands, manufactured in the country have been counted and most of them were found to contain thorium within the permissible limit specified by Atomic Energy Regulatory Board (AERB). (author). 5 refs., 1 fig., 3 tabs.

  12. Distribution of natural radionuclides of uranium and thorium series in the process of artesian water treatment for drinking consumption

    International Nuclear Information System (INIS)

    Grashchenko, S.M.; Gritchenko, Z.G.; Shishkunova, L.V.

    1997-01-01

    Distribution of natural radionuclides of uranium and thorium series during the treatment of artesian water for drinking consumption is studied using vacuum-emanation and gamma spectrometry methods. During the water treatment hydroxide precipitates are produced at the station, which are isolated using a sand filter, radium isotopes being coprecipitated alongside with them. As a result of this radioactive waste is accumulated at the station, radium isotope concentration in it being equivalent to radium isotope concentration in uranium-thorium ores with 0:11% uranium and 0.56% thorium content. radium isotope concentration in water, delivered to the user do not exceed the established domestic normatives do not exceed the established domestic normatives

  13. MRPP: multiregion processing plant code

    International Nuclear Information System (INIS)

    Kee, C.W.; McNeese, L.E.

    1976-09-01

    The report describes the machine solution of a large number (approximately 52,000) of simultaneous linear algebraic equations in which the unknowns are the concentrations of nuclides in the fuel salt of a fluid-fueled reactor (MSBR) having a continuous fuel processing plant. Most of the equations define concentrations at various points in the processing plant. The code allows as input a generalized description of a processing plant flowsheet; it also performs the iterative adjustment of flowsheet parameters for determination of concentrations throughout the flowsheet, and the associated effect of the specified processing mode on the overall reactor operation

  14. Model Matematik Reduksi Thorium dalam Proses Elektrokoagulasi

    Directory of Open Access Journals (Sweden)

    Prayitno

    2017-11-01

    Full Text Available Thorium reduction by electrocoagulation has been conducted on radioactive waste with thorium contaminant grade of 5x10-4Kg/l through a batch system using aluminium electrodes. This study aims to determine a mathematical model of thorium reduction through speed reaction, constante reaction rate and reaction order which are affected by electrocoagulation process parameters like voltage, time, electrode distance, and pH. The research results the optimum voltage condition at 12.5 V at 1 cm electrode spacing, pH 7, and 30 minutes of processing time with 99.6 % efficiency. Prediction on thorium decline rate constante is obtained through mathematic integral method calculation. The research results thorium decline rate is following second order constante with its value at 5x10-3KgL-1min-1.

  15. Contributions to the thorium occupational exposure in Brazil

    International Nuclear Information System (INIS)

    Cunha, Kenya Moore de Almeida Dias da

    1997-01-01

    There are around 15.000 workers in Brazil involved in the mining and milling processes of thorium bearing minerals. It is necessary to estimate the exposure of workers to airborne particulate containing thorium to estimate the risk associated with the inhalation of aerosols. The aims of this study were: - to develop a national cascade impactor and - to characterize the exposure of workers to airborne particulate containing Th in two plants and one industry that were chosen. Plant A and Pant B process niobium ore and industry C uses thorium nitrate to manufacture gas mantle. The national cascade impactor - ICN was developed to collect particulate in the range of 0,64 up to 19,4 μm. Its advantage over commercially available cascade impactors is the selections of particulate in the respirable and inhalable fractions of aerosol. The experimental calibration of the ICN agreed with the theoretical calibration. The results obtained with the ICN were compared to the ones obtained with other selective air samplers, in 3 plants. The particle size distribution and the Th mass concentration were determined in those plants. The size distribution of particulate containing Nb. U Zr, Pb. Fe, Y and Sr, and the elemental mass concentration was determined. A group of workers in installations B and C were also monitored through bioassay analysis of Th excreted in urine and feces. Air and bioassay results have shown that the systemic incorporation of Th is not significant. (author)

  16. Thorium inorganic gels

    International Nuclear Information System (INIS)

    Genet, M.; Brandel, V.

    1988-01-01

    The optimum pH and concentration values of thorium salts and oxoacids or oxoacid salts which lead to transparent and stable inorganic gels have been determined. The isotherm drying process of the gel at 50 0 C leads successively to a partly dehydrated gel, then, to the formation of an unusual liquid phase and, finally to a dry amorphous solid phase which is still transparent. This kind of transparent inorganic gels and amorphous phase can be used as matrices for spectroscopic studies [fr

  17. 78 FR 21352 - Update on Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites

    Science.gov (United States)

    2013-04-10

    ... reimbursement ceilings). Title X requires DOE to reimburse eligible uranium and thorium licensees for certain... DEPARTMENT OF ENERGY Update on Reimbursement for Costs of Remedial Action at Active Uranium and... not currently available for reimbursement for cleanup work performed by licensees at eligible uranium...

  18. The environmental behaviour of uranium and thorium

    International Nuclear Information System (INIS)

    Sheppard, M. I.

    1980-08-01

    Uranium and thorium have had many uses in the past, and their present and potential use as nuclear fuels in energy production is very significant. Both elements, and their daughter products, are of environmental interest because they may have effects from the time of mining to the time of ultimate disposal of used nuclear fuel. To assess the impact on the environment of man's use and disposal of uranium and thorium, we must know the physical, chemical and biological behaviour of these elements. This report summarizes the literature, updating and extending earlier reviews pertaining to uranium and thorium. The radiological properties, chemistry, forms of occurrence in nature, soil interactions, as well as distribution coefficients and mode of transport are discussed for both elements. In addition, uranium and thorium concentrations in plants, plant transfer coefficients, concentrations in soil organisms and methods of detection are summarized. (auth)

  19. Process control in biogas plants

    DEFF Research Database (Denmark)

    Holm-Nielsen, Jens Bo; Oleskowicz-Popiel, Piotr

    2013-01-01

    Efficient monitoring and control of anaerobic digestion (AD) processes are necessary in order to enhance biogas plant performance. The aim of monitoring and controlling the biological processes is to stabilise and optimise the production of biogas. The principles of process analytical technology...

  20. Thoron and associated risks in the handling of thorium compounds

    International Nuclear Information System (INIS)

    Pradel, J.; Billard, F.

    1959-01-01

    1. Thorium compounds continually give off thoron and its daughters and their radioactivity can constitute a danger for operators who may inhale them. 2. By analogy with radon the maximum admissible content in air of thoron and its daughters has been set at 10 -7 μc/cm 3 . However the differences in behaviour between radon and its active deposit on the one hand, and thoron and its daughters on the other, appear great enough to justify more thorough investigation. In fact it seemed probable that, contrary to what takes place with radon, the thoron + thorium A content at a given point may differ appreciable from the thorium B + thorium C + thorium C' + thorium C'' content at the same point, because of the considerable differences in half-life which allow a greater or lesser distribution. 3. To determine the relative concentrations it was necessary to develop a method for estimating thoron in equilibrium with thorium A, the measurement of thorium B and its daughters being carried out in the conventional way by counting the activity collected on a filter. 4. Another object of this study was to estimate the danger presented by thoron in equilibrium with thorium A in the immediate vicinity of thorium sources, in a plant extracting thorium from urano-thorianite. (author) [fr

  1. Toxicology of thorium cycle nuclides

    International Nuclear Information System (INIS)

    Ballou, J.E.

    1984-01-01

    The purpose of this project is to investigate the biological hazards associated with uranium-thorium breeder fuels and fuel recycle process solutions. Initial studies emphasize the metabolism and long-term biological effects of inhaled 233 U- 232 U nitrate and oxide fuel materials and of 231 Pa, a major, long-lived, radioactive waste product. 1 figure, 3 tables

  2. Using airborne GAMMA-ray spectrometry (uranium, thorium, potassium) to quantify weathering and erosion processes

    International Nuclear Information System (INIS)

    Carrier, F.

    2005-01-01

    The airborne gamma-ray spectrometry survey carried out on the Armorican Massif provided soil contents in U, Th and K in ppm. Chemical and mechanical erosion processes within a homogeneous geological unit have been estimated using their variations and those of the 137 Cs. Our new approach, based on a multivariate analysis (hierarchic ascending classification), integrates the airborne gamma-ray spectrometry data, with their broad spatial distribution, together with precisely located station data (major elements, traces and isotopic geochemistry) resulting from a soil and river water erosion products survey. The total export of potassium was estimated in any point of an area catchment (50-m resolution) until 17+2 t/km 2 /a for a 50-m thick weathering profile. Erosion study by river sampling provide important biases, for the perennial river does not integrate the whole range of erosion products: the geochemical signature of the valleys is currently more represented than plateau areas. (author)

  3. Concentration levels of rare-earth elements and thorium on plants from the Morro de Ferro environment as an indicator for the biological availability of transuranium elements

    International Nuclear Information System (INIS)

    Miekeley, N.; Casartelli, E.A.; Dotto, R.M.

    1994-01-01

    Plants and soils from a natural thorium and rare-earth element occurrence (Morro do Ferro, Brazil) were analyzed by alpha spectrometry (Th) and ICP-AES (REE), after pre-concentration of the elements by solvent extraction, co-precipitation and ion exchange procedures. Leaching experiments with humic acid solutions and different soils were performed to estimate the fraction of elements biologically available. High concentrations of the light rare-earth elements (LREE) and of Th, reaching some hundreds of μg/g-ash, were measured in plant leaves from the areas of the highest concentration of these elements in soil and in near-surface waters. Chondrite normalized REE plots of plant leaves and corresponding soils are very similar, suggesting that there is no significant fractionation between the REE during uptake from the soil solution and incorporation into the leaves. However, Ce-depletion was observed for some plant species, increasing for Solanum ciliatum in the sequence: leaves -3 to 10 -2 . Leaching experiments confirmed the importance of humic acid complexation for the bio-uptake of Th and REE and further showed that only a very small fraction of these elements in soil is leachable. The implications of these results on the calculated CR's will be discussed. (author) 26 refs.; 5 figs.; 5 tabs

  4. Process and plant safety

    CERN Document Server

    Hauptmanns, Ulrich

    2015-01-01

    Accidents in technical installations are random events. Hence they cannot be totally avoided. Only the probability of their occurrence may be reduced and their consequences be mitigated. The book proceeds from hazards caused by materials and process conditions to indicating technical and organizational measures for achieving the objectives of reduction and mitigation. Qualitative methods for identifying weaknesses of design and increasing safety as well as models for assessing accident consequences are presented. The quantitative assessment of the effectiveness of safety measures is explained. The treatment of uncertainties plays a role there. They stem from the random character of the accident and from lacks of knowledge on some of the phenomena to be addressed. The reader is acquainted with the simulation of accidents, safety and risk analyses and learns how to judge the potential and limitations of mathematical modelling. Risk analysis is applied amongst others to “functional safety” and the determinat...

  5. Mass Customization of process plants

    DEFF Research Database (Denmark)

    Hvam, Lars

    2006-01-01

    This case study describes how F.L.Smidth A/S, a manufacturer of large processing plants for cement production, has applied the principles of mass customisation in the area of highly complex, custom engineered products. The company has based its sales process on a configuration system to achieve...

  6. Large-scale nuclear energy from the thorium cycle

    International Nuclear Information System (INIS)

    Lewis, W.B.; Duret, M.F.; Craig, D.S.; Veeder, J.I.; Bain, A.S.

    1973-02-01

    The thorium fuel cycle in CANDU (Canada Deuterium Uranium) reactors challenges breeders and fusion as the simplest means of meeting the world's large-scale demands for energy for centuries. Thorium oxide fuel allows high power density with excellent neutron economy. The combination of thorium fuel with organic caloporteur promises easy maintenance and high availability of the whole plant. The total fuelling cost including charges on the inventory is estimated to be attractively low. (author) [fr

  7. The influence of different hydroponic conditions on thorium uptake by Brassica juncea var. foliosa.

    Science.gov (United States)

    Wang, Dingna; Zhou, Sai; Liu, Li; Du, Liang; Wang, Jianmei; Huang, Zhenling; Ma, Lijian; Ding, Songdong; Zhang, Dong; Wang, Ruibing; Jin, Yongdong; Xia, Chuanqin

    2015-05-01

    The effects of different hydroponic conditions (such as concentration of thorium (Th), pH, carbonate, phosphate, organic acids, and cations) on thorium uptake by Brassica juncea var. foliosa were evaluated. The results showed that acidic cultivation solutions enhanced thorium accumulation in the plants. Phosphate and carbonate inhibited thorium accumulation in plants, possibly due to the formation of Th(HPO4)(2+), Th(HPO4)2, or Th(OH)3CO3 (-) with Th(4+), which was disadvantageous for thorium uptake in the plants. Organic aids (citric acid, oxalic acid, lactic acid) inhibited thorium accumulation in roots and increased thorium content in the shoots, which suggested that the thorium-organic complexes did not remain in the roots and were beneficial for thorium transfer from the roots to the shoots. Among three cations (such as calcium ion (Ca(2+)), ferrous ion (Fe(2+)), and zinc ion (Zn(2+))) in hydroponic media, Zn(2+) had no significant influence on thorium accumulation in the roots, Fe(2+) inhibited thorium accumulation in the roots, and Ca(2+) was found to facilitate thorium accumulation in the roots to a certain extent. This research will help to further understand the mechanism of thorium uptake in plants.

  8. Interpretation of thorium bioassay data

    International Nuclear Information System (INIS)

    Juliao, L.M.Q.C.; Azeredo, A.M.G.F.; Santos, M.S.; Melo, D.R.; Dantas, B.M.; Lipsztein, J.L.

    1994-01-01

    A comparison have been made between bioassay data of thorium-exposed workers from two different facilities. The first of these facilities is a monazite sand extraction plant. Isotopic equilibrium between 232 Th and 238 Th was not observed in excreta samples of these workers. The second facility is a gas mantle factory. An isotopic equilibrium between 232 Th and 228 Th was observed in extra samples. Whole body counter measurements have indicated a very low intake of thorium through inhalation. As the concentration of thorium in feces was very high it was concluded that the main pathway of entrance of the nuclide was ingestion, mainly via contamination through dirty hands. The comparison between the bioassay results of workers from the two facilities shows that the lack of Th isotopic equilibrium observed in the excretion from the workers at the monazite sand plant possibly occurred due to an additional Th intake by ingestion of contaminated fresh food. This is presumably because 228 Ra is more efficiently taken up from the soil by plants, in comparison to 228 Th or 232 Th, and subsequently, 228 Th grows in from its immediate parent, 228 Ra. (author) 5 refs.; 3 tabs

  9. Uses of extraction and ion exchange chromatography in the thorium and rare earths separation from industrial residue generated in thorium purification unity at IPEN. Application of rare earths as catalysts for generation of hydrogen

    International Nuclear Information System (INIS)

    Zini, Josiane

    2010-01-01

    In the 70's a pilot plant for studies of different concentrates processing obtained from the chemical processing of monazite was operated at IPEN / CNEN-SP, with a view to obtaining thorium of nuclear purity. This unity was operated on an industrial scale since 1985, generating around 25 metric tons of residue and was closed in 2002. This waste containing thorium and rare earths was named Retoter (Rejeito de Torio e Terras Raras, in portuguese) and stored in the IPEN Safeguards shed. This paper studies the treatment of the waste, aimed at environmental, radiological and technology. Were studied two cases for the chromatographic separation of thorium from rare earths. One of them was the chromatographic extraction, where the extracting agent tributyl phosphate was supported on polymeric resins Amberlite XAD16. The other method is studied for comparison purposes, since the material used in chromatographic extraction is unprecedented with regard to the separation of thorium, was the ion-exchange chromatography using DOWEX 1-X8 strong cationic resin. Was studied also the chromatographic process of extraction with the extracting agent DEHPA supported on Amberlite XAD16 for the fractionation in groups of rare earths elements. Thorium was separated with high purity for strategic purposes and rare earths recovered free from thorium, were tested as a catalyst for ethanol reforming to hydrogen obtaining which is used in fuel cells for power generation. (author)

  10. Thorium research activities in Japan

    International Nuclear Information System (INIS)

    Sasa, Toshinobu

    2015-01-01

    The nuclear energy policy in Japan is based on the Uranium-Plutonium fuel cycle with Light Water Reactors (LWR) and Fast Breeder Reactors (FBR). After the accident at Fukushima-Daiichi Nuclear Power Plant, the Japanese government recognizes the importance to ensure the flexibility for future nuclear power generation and then, it was specified in the latest Japanese strategic energy plan. Two research groups related to thorium fuelled nuclear systems and fuel cycle was set up in the Atomic Energy Society of Japan in 2013. One is a 'Research Committee on Nuclear Applications of Molten Salt'. The committee was established to discuss the current molten-salt technology including molten-salt cooled reactor, molten-salt fuelled reactor, accelerator driven system, fusion reactor blankets and dry reprocessing processes. Throughout two years discussion, the committee summarizes a current state of the art and issues of molten-salt application systems. Committee also discussed the handling technologies for molten-salt reactors especially in China and United Kingdom, issues of molten-salt application to fusion reactor, dry reprocessing of spent nuclear fuel, and non-nuclear application of molten-salt. Term of the committee will be extended for further research activities

  11. A new method for determination of trace amount thorium-spectrophotometric determination of thorium in aqueous phase by chlorophosphonazo-mA

    International Nuclear Information System (INIS)

    Xia Yuanxian; Qian Hesheng

    1986-01-01

    In this paper the spectrophotometric method for determination of trace amount of thorium in weak acidic medium by chlorophosphonazo-mA is described. The composition of the complex was estimated to be 1:4 by slope ratio method. The apparent molar absorption of thorium at 675 nm is 9.2 x 10 4 . Beer's law is obeyed for 0-12.0 μg of thorium in 10 ml solution. The coefficient of variation for thorium is 0.88%. The method has been applied to the determination of trace amounts of thorium in the extraction process of thorium

  12. Nuclear energy from thorium

    International Nuclear Information System (INIS)

    Coote, G.E.

    1977-06-01

    Relevant topics in nuclear and reactor physics are outlined. These include: the thorium decay series; generation of fissile from fertile nuclides, in particular U-233 from Th-232; the princiiples underlying thermal breeder reactors; the production of U-232 in thorium fuel and its important influence on nuclear safeguards and the recycling of U-233. Development work is continuing on several types of reactor which could utilise thorium; each of these is briefly described and its possible role is assessed. Other tipics covered include safety aspects of thorium oxide fuel, reprocessing, fabrication of recycle fuel and the possibility of denaturing U-233 by adding natural uranium. It is concluded that previoue arguments for development of the thorium cycle are still valid but those relating to non-proliferation of weapons may become even more compelling. (auth.)

  13. Idaho Chemical Processing Plant Process Efficiency improvements

    International Nuclear Information System (INIS)

    Griebenow, B.

    1996-03-01

    In response to decreasing funding levels available to support activities at the Idaho Chemical Processing Plant (ICPP) and a desire to be cost competitive, the Department of Energy Idaho Operations Office (DOE-ID) and Lockheed Idaho Technologies Company have increased their emphasis on cost-saving measures. The ICPP Effectiveness Improvement Initiative involves many activities to improve cost effectiveness and competitiveness. This report documents the methodology and results of one of those cost cutting measures, the Process Efficiency Improvement Activity. The Process Efficiency Improvement Activity performed a systematic review of major work processes at the ICPP to increase productivity and to identify nonvalue-added requirements. A two-phase approach was selected for the activity to allow for near-term implementation of relatively easy process modifications in the first phase while obtaining long-term continuous improvement in the second phase and beyond. Phase I of the initiative included a concentrated review of processes that had a high potential for cost savings with the intent of realizing savings in Fiscal Year 1996 (FY-96.) Phase II consists of implementing long-term strategies too complex for Phase I implementation and evaluation of processes not targeted for Phase I review. The Phase II effort is targeted for realizing cost savings in FY-97 and beyond

  14. Thorium exposure in a niobium mine

    International Nuclear Information System (INIS)

    Fonseca, Adelaide M. Gondin da

    1995-01-01

    The workers involved in the mineral process to obtain Nb-Fe alloy are exposure to thorium. Internal contamination with radioactive materials is a common problem. This is caused by presence of U and Th and their natural decay series associated with the mine ore. The examples are the workers at the niobium mine located in the state of Goias. Twenty mine workers were evaluated using in vitro bioassay techniques. Samples of urine and feces from occupationally exposed mine workers were analyzed for thorium isotopes. The fecal samples corresponding to one complete excretion and urine sample corresponding to a 24 hours collection were analyzed using alpha spectrometry. The results of thorium excretion (feces) have shown that in all the samples the 228 Th excretions in high than 232 Th. Thorium concentration in all the urine samples were below limit of detection that is approximately 1 mBq/l. (author). 3 refs., 1 fig., 1 tab

  15. Water processing in power plants

    International Nuclear Information System (INIS)

    Marquardt, K.

    1984-01-01

    Surface water can be treated to a high degree of efficiency by means of new compact processes. The quantity of chemicals to be dosed can easily be adjusted to the raw water composition by intentional energy supply via agitators. In-line coagulations is a new filtration process for reducing organic substances as well as colloids present in surface water. The content of organic substances can be monitored by measuring the plugging index. Advanced ion-exchanger processes (fluidised-bed, compound fluidised-bed and continuously operating ion exchanger plants) allow the required quantity of chemicals as well as the plant's own water consumption to be reduced, thus minimising the adverse effect on the environment. The reverse-osmosis process is becoming more and more significant due to the low adverse effect on the environment and the given possibilities of automation. As not only ionogenic substances but also organic matter are removed by reverse osmosis, this process is particularly suited for treating surface water to be used as boiler feed water. The process of vacuum degassing has become significant for the cold removal of oxygen. (orig.) [de

  16. Thorium Molten-Salt Nuclear Energy Synergetics

    International Nuclear Information System (INIS)

    Furukawa, Kazuo; Lecocq, A.; Kato, Yoshio; Mitachi, Kohshi.

    1990-01-01

    In the next century, the 'fission breeder' concept will not be practical to solve the global energy problems, including environmental and North-South problems. As a new measure, a simple rational Th molten salt breeding fuel cycle system, named 'Thorium Molten-Salt Nuclear Energy Synergetics (THORIMS-NES)', which composed of simple power stations and fissile producers, is proposed. This is effective to establish the essential improvement in issues of resources, safety, power-size flexibility, anti-nuclear proliferation and terrorism, radiowaste, economy, etc. securing the simple operation, maintenance, chemical processing, and rational breeding fuel cycle. As examples, 155 MWe fuel self-sustaining power station 'FUJI-II', 7 MWe pilot-plant 'miniFUJI-II', 1 GeV-300 mA proton Accelerator Molten-Salt Breeder 'AMSB', and their combined fuel cycle system are explained. (author)

  17. Determination of the total nitrate content of thorium nitrate solution with a selective electrode

    International Nuclear Information System (INIS)

    Wirkner, F.M.

    1979-01-01

    The nitrate content of thorium nitrate solutions is determined with a liquid membrane nitrate selective electrode utilizing the known addition method in 0.1 M potassium fluoride medium as ionic strength adjustor. It is studied the influence of pH and the presence of chloride, sulphate, phosphate, meta-silicate, thorium, rare earths, iron, titanium, uranium and zirconium at the same concentrations as for the aqueous feed solutions in the thorium purification process. The method is tested in synthetic samples and in samples proceeding from nitric dissolutions of thorium hidroxide and thorium oxicarbonate utilized as thorium concentrates to be purified [pt

  18. The thorium fuel cycle

    International Nuclear Information System (INIS)

    Merz, E.R.

    1977-01-01

    The utilization of the thorium fuel cycle has long since been considered attractive owing to the excellent neutronic characteristics of 233 U, and the widespread and cheap thorium resources. Rapidly increasing uranium prices, public reluctance for widespread Pu recycling and expected delays for the market penetration of fast breeders have led to a reconsideration of the thorium fuel cycle merits. In addition, problems associated with reprocessing and waste handling, particularly with re-fabrication by remote handling of 233 U, are certainly not appreciably more difficult than for Pu recycling. To divert from uranium as a nuclear energy source it seems worth while intensifying future efforts for closing the Th/ 233 U fuel cycle. HTGRs are particularly promising for economic application. However, further research and development activities should not concentrate on this reactor type alone. Light- and heavy-water-moderated reactors, and even future fast breeders, may just as well take advantage of a demonstrated thorium fuel cycle. (author)

  19. Thorium ore deposits

    International Nuclear Information System (INIS)

    Angelelli, Victorio.

    1984-01-01

    The main occurences of the thorium minerals of the Argentine Republic which have not been exploited, due to their reduced volume, are described. The thoriferous deposits have three genetic types: pegmatitic, hydrothermal and detritic, being the most common minerals: monazite, thorite and thorogummite. The most important thorium accumulations are located in Salta, being of less importance those of Cordoba, Jujuy and San Juan. (M.E.L.) [es

  20. Much cleaner nuclear energy from thorium

    International Nuclear Information System (INIS)

    Damveld, H.

    1998-01-01

    In Zaragoza, Spain, an experimental thorium reactor will be built, which can be an alternative for uranium reactors. A brief impression is given of activities in the Netherlands with respect to the so-called Energy Amplifier (EA), which is a combination of a nuclear power plant and an accelerator. EA is the idea of C. Rubbia of CERN in Geneva, Switzerland

  1. Lanthanides, thorium, iodine in terrestrail invertebrates

    International Nuclear Information System (INIS)

    Zhulidov, A.V.; Pokarzhevskij, A.D.; Katargin, N.V.; AN SSSR, Moscow

    1991-01-01

    It is shown that among examined terrestrial invertebrates the highest levels on lanthanide and thorium concentration are typical for animals, feeding on plant tissues - earthworms, molluscs, diploid. It is shown that there are no reasons to hope, that regularities of migration of transuranium elements and lanthanides in tropic chains are identical

  2. Thorium fuel cycle analysis

    Energy Technology Data Exchange (ETDEWEB)

    Yamaji, K [Central Research Inst. of Electric Power Industry, Tokyo (Japan)

    1980-07-01

    Systems analysis of the thorium cycle, a nuclear fuel cycle accomplished by using thorium, is reported in this paper. Following a brief review on the history of the thorium cycle development, analysis is made on the three functions of the thorium cycle; (1) auxiliary system of U-Pu cycle to save uranium consumption, (2) thermal breeder system to exert full capacity of the thorium resource, (3) symbiotic system to utilize special features of /sup 233/U and neutron sources. The effects of the thorium loading in LWR (Light Water Reactor), HWR (Heavy Water Reactor) and HTGR (High Temperature Gas-cooled Reactor) are considered for the function of auxiliary system of U-Pu cycle. Analysis is made to find how much uranium is saved by /sup 233/U recycling and how the decrease in Pu production influences the introduction of FBR (Fast Breeder Reactor). Study on thermal breeder system is carried out in the case of MSBR (Molten Salt Breeder Reactor). Under a certain amount of fissile material supply, the potential system expansion rate of MSBR, which is determined by fissile material balance, is superior to that of FBR because of the smaller specific fissile inventory of MSBR. For symbiotic system, three cases are treated; i) nuclear heat supply system using HTGR, ii) denatured fuel supply system for nonproliferation purpose, and iii) hybrid system utilizing neutron sources other than fission reactor.

  3. Study of field assessment methods and worker risks for processing alternatives to support principles for FUSRAP waste materials. Part 1: Treatment methods and comparative risks of thorium removal from waste residues

    Energy Technology Data Exchange (ETDEWEB)

    Porter, R.D.; Hamby, D.M.; Martin, J.E.

    1997-07-01

    This study was done to examine the risks of remediation and the effectiveness of removal methods for thorium and its associated radioactive decay products from various soils and wastes associated with DOE`s Formerly Utilized Sites Remedial Action Program (FUSRAP). Its purpose was to provide information to the Environmental Management Advisory Board`s FUSRAP Committee for use in its deliberation of guiding principles for FUSRAP sites, in particular the degree to which treatment should be considered in the FUSRAP Committee`s recommendations. Treatment of FUSRAP wastes to remove thorium could be beneficial to management of lands that contain thorium if such treatment were effective and cost efficient. It must be recognized, however, that treatment methods invariably require workers to process residues and waste materials usually with bulk handling techniques. These processes expose workers to the radioactivity in the materials, therefore, workers would incur radiological risks in addition to industrial accident risks. An important question is whether the potential reduction of future radiological risks to members of the public justifies the risks that are incurred by remediation workers due to handling materials. This study examines, first, the effectiveness of treatment and then the risks that would be associated with remediation. Both types of information should be useful for decisions on whether and how to apply thorium removal methods to FUSRAP waste materials.

  4. Study of field assessment methods and worker risks for processing alternatives to support principles for FURSRAP waste materials. Part 1: Treatment methods and comparative risks of thorium removal from waste residues

    International Nuclear Information System (INIS)

    Porter, R.D.; Hamby, D.M.; Martin, J.E.

    1997-07-01

    This study was done to examine the risks of remediation and the effectiveness of removal methods for thorium and its associated radioactive decay products from various soils and wastes associated with DOE's Formerly Utilized Sites Remedial Action Program (FUSRAP). Its purpose was to provide information to the Environmental Management Advisory Board's FUSRAP Committee for use in its deliberation of guiding principles for FUSRAP sites, in particular the degree to which treatment should be considered in the FUSRAP Committee's recommendations. Treatment of FUSRAP wastes to remove thorium could be beneficial to management of lands that contain thorium if such treatment were effective and cost efficient. It must be recognized, however, that treatment methods invariably require workers to process residues and waste materials usually with bulk handling techniques. These processes expose workers to the radioactivity in the materials, therefore, workers would incur radiological risks in addition to industrial accident risks. An important question is whether the potential reduction of future radiological risks to members of the public justifies the risks that are incurred by remediation workers due to handling materials. This study examines, first, the effectiveness of treatment and then the risks that would be associated with remediation. Both types of information should be useful for decisions on whether and how to apply thorium removal methods to FUSRAP waste materials

  5. Light water reactors with a denatured thorium fuel cycle

    International Nuclear Information System (INIS)

    1978-05-01

    Discussed in this paper is the performance of denatured thorium fuel cycles in PWR plants of conventional design, such as those currently in operation or under construction. Although some improvement in U 3 O 8 utilization is anticipated in PWRs optimized explicitly for the denatured thorium fuel cycle, this paper is limited to a discussion of the performance of denatured thorium fuels in conventional PWRs and consequently the data presented is representative of the use of thorium fuel in existing PWRs or those presently under construction. In subsequent sections of this paper, the design of the PWR, its performance on the denatured thorium fuel cycle, safety, accident and environmental considerations, and technological status and R and D requirements are discussed

  6. Th-100 Nuclear Power Plant

    International Nuclear Information System (INIS)

    Reitsma, Frederik

    2013-01-01

    Steenkampskraal Thorium Limited (STL) is a private company which is designing, marketing, licensing and commercializing a 100MWt thorium fueled pebble bed reactor. The concept plant design has been completed and work on the basic design has started. First site to determine the fuel cycle employed. Strong emphasis is placed on modular construction to reduce costs. STL hopes to start the licensing process within the next 6-8 months

  7. REGENERATION OF FISSION-PRODUCT-CONTAINING MAGNESIUM-THORIUM ALLOYS

    Science.gov (United States)

    Chiotti, P.

    1964-02-01

    A process of regenerating a magnesium-thorium alloy contaminated with fission products, protactinium, and uranium is presented. A molten mixture of KCl--LiCl-MgCl/sub 2/ is added to the molten alloy whereby the alkali, alkaline parth, and rare earth fission products (including yttrium) and some of the thorium and uranium are chlorinated and

  8. ORNL process waste treatment plant modifications

    International Nuclear Information System (INIS)

    Bell, J.P.

    1982-01-01

    The ORNL Process Waste Treatment Plant removes low levels of radionuclides (primarily Cs-137 and Sr-90) from process waste water prior to discharge. The previous plant operation used a scavenging precipitaton - ion exchange process which produced a radioactive sludge. In order to eliminate the environmental problems associated with sludge disposal, the plant is being converted to a new ion exchange process without the precipitation process

  9. Processes for manufacture of products from plants

    DEFF Research Database (Denmark)

    2010-01-01

    Disclosed herein is a process for inhibiting browning of plant material comprising adding a chelating agent to a disrupted plant material and adjusting the pH to a value of 2.0 to 4.5. Processes for manufacture of soluble and insoluble products from a plant material are also disclosed. Soluble...

  10. Thorium impact on tobacco root transcriptome

    Czech Academy of Sciences Publication Activity Database

    Mazari, Kateřina; Landa, Přemysl; Přerostová, Sylva; Müller, Karel; Vaňková, Radomíra; Soudek, Petr; Vaněk, Tomáš

    2017-01-01

    Roč. 325, MAR 5 (2017), s. 163-169 ISSN 0304-3894 R&D Projects: GA MŠk(CZ) LD11073; GA MŠk(CZ) LD13029 Institutional support: RVO:61389030 Keywords : arabidopsis-thaliana roots * juncea var. foliosa * cadmium accumulation * deficiency responses * mineral- nutrition * gene-expression * plant transfer * iron uptake * uranium * soil * Microarray * Thorium * Gene expression * Toxicity * Nicotiana tabacum Subject RIV: ED - Physiology OBOR OECD: Plant sciences, botany Impact factor: 6.065, year: 2016

  11. ZIRCONIUM-CLADDING OF THORIUM

    Science.gov (United States)

    Beaver, R.J.

    1961-11-21

    A method of cladding thorium with zirconium is described. The quality of the bond achieved between thorium and zirconium by hot-rolling is improved by inserting and melting a thorium-zirconium alloy foil between the two materials prior to rolling. (AEC)

  12. Thorium utilization in power reactors

    International Nuclear Information System (INIS)

    Saraceno; Marcos.

    1978-10-01

    In this work the recent (prior to Aug, 1976) literature on thorium utilization is reviewed briefly and the available information is updated. After reviewing the nuclear properties relevant to the thorium fuel cycle we describe briefly the reactor systems that have been proposed using thorium as a fertile material. (author) [es

  13. Toxicity of thorium cycle nuclides

    International Nuclear Information System (INIS)

    Ballou, J.E.

    1986-01-01

    The purpose of this project is to investigate the biological hazards associated with uranium-thorium breeder fuels and fuel recycle process solutions. Initial studies emphasize the metabolism and long-term biological effects of inhaled 233 U- 232 U nitrate and oxide fuel materials and of 231 Pa, a major, long-lived, radioactive waste product. Rats were used as test animals. Dose-response relationships for malignant lung-tumor and bone-tumor induction after 232 UO 2 (NO 3 ) 2 inhalation are discussed. 2 figures, 1 table

  14. Determination of traces of thorium in ammonium/sodium diuranate by ICP-AES method

    International Nuclear Information System (INIS)

    Nair, V.R.; Kartha, K.N.M.

    1999-01-01

    Full text: Indian Rare Earths Ltd., Alwaye, produces ammonium diuranate from the thorium concentrate, obtained during monazite processing. This process involves a series of steps. The final uranium product obtained always contains microgram amounts of thorium as impurity. An analytical procedure has been standardised for the estimation of microgram amounts of thorium in ammonium/sodium diuranate. The method involves solvent extraction of uranium by using a tertiary amine followed by the determination of thorium by ICP-AES method in the raffinate. The recoveries of thorium were checked by standard addition to the uranium matrix. Limit of detection is adequate for the analysis of nuclear grade material

  15. Characterisation of radioactivity carrying aerosol in a mineral sand processing plant

    International Nuclear Information System (INIS)

    Jeffries, C.; Morawska, L.

    1998-01-01

    The techniques used to separate heavy mineral sand into mineral products produce a large amount of airborne particulate. Some of these particles are radioactive which is due to the thorium and, to a lesser extent, the uranium content of mineral sands. This study has investigated both the radioactive and respirable particle components (<10 μm) of the aerosol in a dry sand processing plant in Brisbane, Australia. A number of different measurement techniques have been used to characterise the aerosol in the plant. The mass, number and activity distributions have been determined by an eight stage cascade impactor and an Aerodynamic Particle Sizer (APS) with both instruments measuring 0.4 to 10 μm. Measurements of radon progeny concentrations and the extent of radon progeny attachment to micrometer sized particles has been investigated, as well as the extent of airborne thorium and uranium. The preliminary results from two sites are presented and comments are made on the relationship between total and radioactive aerosol

  16. Thorium contents in soils, vegetables, cereals, and fruits

    International Nuclear Information System (INIS)

    Frindik, O.

    1989-01-01

    Thorium contents (α-activities of the naturally occurring isotopes Th-228, Th-230, and Th-232) were detrmined in soils, vegetables, cereals, and fruits. The thorium content of plants depends on the degree of contamination by soil resuspension and thus on the specific surface of the plants. The activity of the isotope Th-230 is almost the same as that of the main isotope Th-232. Th-228, with about the same activity as Th-232 in soil, increases to about 10-fold the activity in vegetables, 29-fold in sweet chestnuts and 740-fold in Brazil nuts. Thorium concentration factors from the soil to these vegetable products are calculated; they include the total concentration, not only the soluble portion of thorium. (orig.) [de

  17. Plant-based remediation processes

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Dharmendra Kumar (ed.) [Belgian Nuclear Research Centre (SCK.CEN), Mol (Belgium). Radiological Impact and Performance Assessment Division

    2013-11-01

    A valuable source of information for scientists in the field of environmental pollution and remediation. Describes the latest biotechnological methods for the treatment of contaminated soils. Includes case studies and protocols. Phytoremediation is an emerging technology that employs higher plants for the clean-up of contaminated environments. Basic and applied research have unequivocally demonstrated that selected plant species possess the genetic potential to accumulate, degrade, metabolize and immobilize a wide range of contaminants. The main focus of this volume is on the recent advances of technologies using green plants for remediation of various metals and metalloids. Topics include biomonitoring of heavy metal pollution, amendments of higher uptake of toxic metals, transport of heavy metals in plants, and toxicity mechanisms. Further chapters discuss agro-technological methods for minimizing pollution while improving soil quality, transgenic approaches to heavy metal remediation and present protocols for metal remediation via in vitro root cultures.

  18. The thorium fuel cycle

    International Nuclear Information System (INIS)

    Merz, E.R.

    1977-01-01

    The utilization of the thorium fuel cycle has long since been considered attractive due to the excellent neutronic characteristics of 233 U, and the widespread and cheap thorium resources. Although the uranium ore as well as the separative work requirements are usually lower for any thorium-based fuel cycle in comparison to present uranium-plutonium fuel cycles of thermal water reactors, interest by nuclear industry has hitherto been marginal. Fast increasing uranium prices, public reluctance against widespread Pu-recycling and expected retardations for the market penetration of fast breeders have led to a reconsideration of the thorium fuel cycle merits. In addition, it could be learned in the meantime that problems associated with reprocessing and waste handling, but particularly with a remote refabrication of 233 U are certainly not appreciably more difficult than for Pu-recycling. This may not only be due to psychological constraints but be based upon technological as well as economical facts, which have been mostly neglected up till now. In order to diversify from uranium as a nuclear energy source it seems to be worthwhile to greatly intensify efforts in the future for closing the Th/ 233 U fuel cycle. HTGR's are particularly promising for economic application. However, further R and D activites should not be solely focussed on this reactor type alone. Light and heavy-water moderated reactors, as well as even fast breeders later on, may just as well take advantage of a demonstrated thorium fuel cycle. A summary is presented of the state-of-the-art of Th/ 233 U-recycling technology and the efforts still necessary to demonstrate this technology all the way through to its industrial application

  19. Practical introduction of thorium fuel cycles

    International Nuclear Information System (INIS)

    Kasten, P.R.

    1982-01-01

    The pracitcal introduction of throrium fuel cycles implies that thorium fuel cycles compete economically with uranium fuel cycles in economic nuclear power plants. In this study the reactor types under consideration are light water reactors (LWRs), heavy water reactors (HWRs), high-temperature gas-cooled reactors (HTGRs), and fast breeder reactors (FBRs). On the basis that once-through fuel cycles will be used almost exclusively for the next 20 or 25 years, introduction of economic thorium fuel cycles appears best accomplished by commercial introduction of HTGRs. As the price of natural uranium increases, along with commercialization of fuel recycle, there will be increasing incentive to utilize thorium fuel cycles in heavy water reactors and light water reactors as well as in HTGRs. After FBRs and fuel recycle are commercialized, use of thorium fuel cycles in the blanket of FBRs appears advantageous when fast breeder reactors and thermal reactors operate in a symbiosis mode (i.e., where 233 U bred in the blanket of a fast breeder reactor is utilized as fissile fuel in thermal converter reactors)

  20. Chemical process engineering in the transuranium processing plant

    International Nuclear Information System (INIS)

    Collins, E.D.; Bigelow, J.E.

    1976-01-01

    Since operation of the Transuranium Processing Plant began, process changes have been made to counteract problems caused by equipment corrosion, to satisfy new processing requirements, and to utilize improved processes. The new processes, equipment, and techniques have been incorporated into a sequence of steps which satisfies all required processing functions

  1. Immobilization of thorium over fibroin by polyacrylonitrile (PAN)

    International Nuclear Information System (INIS)

    Aslani, M.A.A.; Akyil, S.; Eral, M.

    1997-01-01

    This report describes a process for immobilization of thorium over fibroin, which was used as a bio-adsorbant, by polyacrylonitrile. The amounts of thorium in aqueous solutions which may be leached in various aqueous ambients were detected by a spectrophotometer. The results show that polyacrylonitrile processes are feasible to immobilize spent fibroins. The leachability of the materials immobilized with polyacrylonitrile can meet the requirements of storage and final disposal. The leachability of thorium ions from immobilized spent fibroin was rather low for 8 months

  2. The indispensable role of thorium for creating a sustainable society

    International Nuclear Information System (INIS)

    Kamei, T.

    2012-01-01

    Several approaches are required in parallel for constructing a sustainable society. One of them is to fight against global warming. The other one is to make this world nuclear weapon free. Nuclear power has been used for peaceful purpose because nuclear power produces electricity without emitting CO 2 . Nearly 15% of world electricity is produced by nuclear power. Through nuclear power plant has a possibility of severe accident such as Fukushima Daiichi, its advantage is still valuable for the world. President Obama's speech in Prague in 2009 brought a impact to the world to move toward the world without nuclear weapon. The remaining subject is how to treat dismantled fissionable materials. Existing nuclear power plants utilize uranium because only uranium contains natural occurring fissionable material, uranium-235. The spent uranium fuel contains fissionable plutonium-239. Thus, uranium fuel cycle always accompanies possibility of nuclear proliferation. Thorium plays an important role for both solving global warming and nuclear weapon. Fertile thorium can be used as nuclear fuel by support of fissionable plutonium-239 from spent uranium fuel or weapon head. Preliminary calculation indicates that the USA's and Russia's dismantle nuclear weapon enable to start more than 10 GWe of thorium nuclear power plants. In addition, plutonium-239 obtained from uranium fuel is available of 392 GWe of thorium nuclear power. Uranium-233 coming from thorium is also a fissionable but it is hard to be used for weapon because of its accompanied gamma-ray. Thorium itself is now obtained as by-product of rare-earth mining, which is used for high-tech products including photovoltaic cell, wind-mill, and hybrid-vehicle. However, thorium is not taken care adequately and becomes environmental hazard. Both to take care of environment, to support implementation of high-tech product and to make the world without nuclear weapon, a comprehensive role of thorium will be presented

  3. A review on the status of development in thorium-based nuclear fuels

    International Nuclear Information System (INIS)

    Lee, Young Woo; Na, S. H.; Lee, Y. W.; Kim, H. S.; Kim, S. H.; Joung, C.Y.

    2000-02-01

    Thorium as an alternative nuclear energy source had been widely investigated in the 1950s-1960s because it is more abundant than uranium, but the studies of thorium nuclear fuel cycle were discontinued by political and economic reasons in the 1970s. Recently, however, renewed interest was vested in thorium-based nuclear fuel cycle because it may generate less long-lived minor actinides and has a lower radiotoxicity of high level wastes after reprocessing compared with the thorium fuel cycle. In this state-of the art report, thorium-based nuclear cycle. In this state-of the art report, thorium-based nuclear fuel cycle and fuel fabrication processes developed so far with different reactor types are reviewed and analyzed to establish basic technologies of thorium fuel fabrication which could meet our situation. (author)

  4. Issues evaluation process at Rocky Flats Plant

    International Nuclear Information System (INIS)

    Smith, L.C.

    1992-01-01

    This report describes the issues evaluation process for Rocky Flats Plant as established in July 1990. The issues evaluation process was initiated February 27, 1990 with a Charter and Process Overview for short-term implementation. The purpose of the process was to determine the projects required for completion before the Phased Resumption of Plutonium Operations. To determine which projects were required, the issues evaluation process and emphasized risk mitigation, based on a ranking system. The purpose of this report is to document the early design of the issues evaluation process to record the methodologies used that continue as the basis for the ongoing Issues Management Program at Rocky Flats Plant

  5. Model feedstock supply processing plants

    Directory of Open Access Journals (Sweden)

    V. M. Bautin

    2013-01-01

    Full Text Available The model of raw providing the processing enterprises entering into vertically integrated structure on production and processing of dairy raw materials, differing by an orientation on achievement of cumulative effect by the integrated structure acting as criterion function which maximizing is reached by optimization of capacities, volumes of deliveries of raw materials and its qualitative characteristics, costs of industrial processing of raw materials and demand for dairy production is developed.

  6. Lattice dynamics of thorium

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, J [Agra Coll. (India). Dept. of Physics

    1977-03-01

    In the present work, a local model pseudopotential has been proposed to study the lattice dynamics of thorium. The model potential depends on the core and ionic radii, and accounts for the s-d-f hybridization effects in a phenomenological way. When this form of potential is applied to derive the photon dispersion curves of Th, sufficiently good agreement is found between the computed and experimental results.

  7. Thorium-230 contamination

    International Nuclear Information System (INIS)

    Noey, K.C.; Liedle, S.D.; Hickey, C.R.; Doane, R.W.

    1989-01-01

    The authors are currently performing radiological surveys on approximately ninety properties in the St. Louis, Missouri area as part of the U.S. Department of Energy's Formerly Utilized Sites Remedial Action Program. The properties involved are the St. Louis Airport Site, Latty Avenue Properties, St. Louis Downtown Site, Coldwater Creek, and the associated roads and vicinity properties. The primary radioactive contaminant on these properties is thorium-230. Since field instrumentation is not available to detect the presence of alpha-emitting contamination in soil, soil samples are being collected and sent to an analytical laboratory for analysis. Thorium-230 analysis is costly and time-consuming, and as a result, soil sample analysis results are not available to help direct the field sampling program. This paper provides discussion of the manner in which the properties became radioactively contaminated, followed by a discussion of the difficulties associated with the detection of thorium-230. Finally, new methodologies for detecting alpha-emitting radionuclides in the field are described

  8. Recovery of lead-208 radiogenic of residues of thorium with rare earth

    International Nuclear Information System (INIS)

    Ferreira, J.C.; Freitas, A.A. de; Seneda, J.A.F.; Carvalho, M.S. de; Abrao, A.

    2008-01-01

    In the middle of the years 1970 in IPEN, considerable work for the purification and conversion of uranium and thorium project, the production of thorium nitrate, a pilot scale from different compounds of Thorium was accomplished; This installation of thorium nitrate produced for national marketing, given the industry of incandescent lighting gas mangles.. The method used by this installation was the purification by solvent extraction with pulsed columns. The thorium was in the organic phase, which was reversed as of thorium nitrate with a high degree of purity. The aqueous phase of this chemical process, containing impurities, some not extracted thorium and virtually all rare earths was precipitated in the form of a hydroxide. This was called RETOTER hydroxide (residue of Thorium and Rare Earth). This residue containing thorium, rare earth and some impurities such as lead-208 product of the decay of thorium-232 were stored in the shed of safeguarding IPEN for further recovery of thorium and rare earth. In this work was studied the recovery of lead-208, nuclear material of interest, separating it by the technique of cementation , where it adds zinc metallic to an acid solution of RETOTER, holding up the lead on the surface of the metallic zinc. (author)

  9. Radkowsky Thorium Fuel Project

    International Nuclear Information System (INIS)

    Todosow, Michael

    2006-01-01

    In the early/mid 1990's Prof. Alvin Radkowsky, former chief scientist of the U.S. Naval Reactors program, proposed an alternate fuel concept employing thorium-based fuel for use in existing/next generation pressurized water reactors (PWRs). The concept was based on the use of a 'seed-blanket-unit' (SBU) that was a one-for-one replacement for a standard PWR assembly with a uranium-based central 'driver' zone, surrounded by a 'blanket' zone containing uranium and thorium. Therefore, the SBU could be retrofit without significant modifications into existing/next generation PWRs. The objective was to improve the proliferation and waste characteristics of the current once-through fuel cycle. The objective of a series of projects funded by the Initiatives for Proliferation Prevention program of the U.S. Department of Energy (DOE-IPP) - BNL-T2-0074,a,b-RU 'Radkowsky Thorium Fuel (RTF) Concept' - was to explore the characteristics and potential of this concept. The work was performed under several BNL CRADAs (BNL-C-96-02 and BNL-C-98-15) with the Radkowsky Thorium Power Corp./Thorium Power Inc. and utilized the technical and experimental capabilities in the Former Soviet Union (FSU) to explore the potential of this concept for implementation in Russian pressurized water reactors (VVERs), and where possible, also generate data that could be used for design and licensing of the concept for Western PWRs. The Project in Russia was managed by the Russian Research Center-?'Kurchatov Institute' (RRC-KI), and included several institutes (e.g., PJSC 'Electrostal', NPO 'LUCH' (Podolsk), RIINM (Bochvar Institute), GAN RF (Gosatomnadzor), Kalininskaja NPP (VVER-1000)), and consisted of the following phases: Phase-1 ($550K/$275K to Russia): The objective was to perform an initial review of all aspects of the concept (design, performance, safety, implementation issues, cost, etc.) to confirm feasibility/viability and identify any 'show-stoppers'; Phase-2 ($600K/$300K to Russia

  10. 238U-234U-230Th chronometry of Fe-Mn crusts: Growth processes and recovery of thorium isotopic ratios of seawater

    International Nuclear Information System (INIS)

    Chabaux, F.; Cohen, A.S.; O'Nions, R.K.; Hein, J.R.

    1995-01-01

    Comparison of ( 234 U) excess /( 238 U) and ( 230 Th)/( 232 Th) activity ratios in oceanic Fe-Mn deposits provides a method for assessing the closed-system behaviour of 238 U- 234 U- 230 Th, as well as variations in the initial uranium and thorium isotopic ratios of the precipitated metal oxides. This approach is illustrated using a Fe-Mn crust from Lotab seamount (Marshall Islands, west equatorial Pacific). Here we report uranium and thorium isotopic compositions in five subsamples from the surface of one large 5 cm diameter botyroid of this crust, and from two depth profiles of the outermost rim of the same botyroid. The decrease of ( 234 U) excess /( 238 U) and ( 230 Th/ 232 Th) activity ratio with depth in the two profiles gives mean growth rates, for the last 150 ka, of 7.8 ± 2 mm/Ma and 6.6 ± 1 mm/Ma, respectively. All data points (surface and core samples) but one, define a linear correlation in the Ln ( 230 Th/ 232 Th) - Ln [( 234 U) excess ( 238 U)] diagram. This correlation indicates that for all points the U-Th system remained closed after the Fe-Mn layer precipitated, and that the different samples possessed the same initial Uranium and thorium isotope ratios. Furthermore, these results show that the preserved surface of this Fe-Mn crust may not be the present-day growth surface, and that the thorium and uranium isotopic ratios of seawater in west equatorial Pacific have not changed during the past 150 ka. The initial thorium activity ratio is estimated from the correlation obtained between Ln( 230 Th/ 232 Th) and Ln [( 234 U) excess /( 238 U)

  11. Environmental control technology for mining, milling, and refining thorium

    International Nuclear Information System (INIS)

    Weakley, S.A.; Blahnik, D.E.; Young, J.K.; Bloomster, C.H.

    1980-02-01

    The purpose of this report is to evaluate, in terms of cost and effectiveness, the various environmental control technologies that would be used to control the radioactive wastes generated in the mining, milling, and refining of thorium from domestic resources. The technologies, in order to be considered for study, had to reduce the radioactivity in the waste streams to meet Atomic Energy Commission (10 CFR 20) standards for natural thorium's maximum permissible concentration (MPC) in air and water. Further regulatory standards or licensing requirements, either federal, state, or local, were not examined. The availability and cost of producing thorium from domestic resources is addressed in a companion volume. The objectives of this study were: (1) to identify the major waste streams generated during the mining, milling, and refining of reactor-grade thorium oxide from domestic resources; and (2) to determine the cost and levels of control of existing and advanced environmental control technologies for these waste streams. Six potential domestic deposits of thorium oxide, in addition to stockpiled thorium sludges, are discussed in this report. A summary of the location and characteristics of the potential domestic thorium resources and the mining, milling, and refining processes that will be needed to produce reactor-grade thorium oxide is presented in Section 2. The wastes from existing and potential domestic thorium oxide mines, mills, and refineries are identified in Section 3. Section 3 also presents the state-of-the-art technology and the costs associated with controlling the wastes from the mines, mills, and refineries. In Section 4, the available environmental control technologies for mines, mills, and refineries are assessed. Section 5 presents the cost and effectiveness estimates for the various environmental control technologies applicable to the mine, mill, and refinery for each domestic resource

  12. Process plant equipment operation, control, and reliability

    CERN Document Server

    Holloway, Michael D; Onyewuenyi, Oliver A

    2012-01-01

    "Process Plant Equipment Book is another great publication from Wiley as a reference book for final year students as well as those who will work or are working in chemical production plants and refinery…" -Associate Prof. Dr. Ramli Mat, Deputy Dean (Academic), Faculty of Chemical Engineering, Universiti Teknologi Malaysia "…give[s] readers access to both fundamental information on process plant equipment and to practical ideas, best practices and experiences of highly successful engineers from around the world… The book is illustrated throughout with numerous black & white p

  13. Thorium cycles and proliferation

    International Nuclear Information System (INIS)

    Lovins, A.B.

    1979-01-01

    This paper analyzes several prevalent misconceptions about nuclear fuel cycles that breed fissile uranium-233 from thorium. Its main conclusions are: U-233, despite the gamma radioactivity of associated isotopes, is a rather attractive material for making fission bombs, and is a credible material for subnational as well as national groups to use for this purpose; (2) pure thorium cycles, which in effect merely substitute U-233 for Pu, would take many decades and much U to establish, and offer no significant safeguards advantage over Pu, cycles; (3) denatured Th-U cycles, which dilute the U-233 with inert U-238 to a level not directly usable in bombs, are not an effective safeguard even against subnational bomb-making; (4) several other features of mixed Th-U cycles are rather unattractive from a safeguards point of view; (5) thus, Th cycles of any kind are not a technical fix for proliferation (national or subnational) and, though probably more safeguardable than Pu cycles, are less so than once-through U cycles that entail no reprocessing; (6) while thorium cycles have some potential technical advantages, including flexibility, they cannot provide major savings in nuclear fuel resources compared to simpler ways of saving neutrons and U; and (7) while advocates of nuclear power may find Th cycles worth exploring, such cycles do not differ fundamentally from U cycles in any of the respects--including safeguards and fuel resources--that are relevant to the broader nuclear debate, and should not be euphorically embraced as if they did

  14. Dose Assurance in Radiation Processing Plants

    DEFF Research Database (Denmark)

    Miller, Arne; Chadwick, K.H.; Nam, J.W.

    1983-01-01

    Radiation processing relies to a large extent on dosimetry as control of proper operation. This applies in particular to radiation sterilization of medical products and food treatment, but also during development of any other process. The assurance that proper dosimetry is performed...... at the radiation processing plant can be obtained through the mediation of an international organization, and the IAEA is now implementing a dose assurance service for industrial radiation processing....

  15. Carbide process picked for Chinese polyethylene plant

    International Nuclear Information System (INIS)

    Alperowicz, N.

    1993-01-01

    Union Carbide (Danbury, CT) is set to sign up its eighth polyethylene (PE) license in China. The company has been selected to supply its Unipol technology to Jilin Chemical Industrial Corp. (JCIC) for a 100,000-m.t./year linear low-density PE (LLDPE) plant at Jilin. The plant will form part of a $2-billion petrochemical complex, based on a 300,000-m.t./year ethylene unit awarded to a consortium made up of Samsung Engineering (Seoul) and Linde. A 10,000-m.t./year butene-1 unit will also be built. Toyo Engineering, Snamprogetti, Mitsubishi Heavy Industries, and Linde are competing for the contract to supply the LLDPE plant. The signing is expected this spring. Two contenders are vying to supply an 80,000-m.t./year phenol plant for JCIC. They are Mitsui Engineering, offering the Mitsui Petrochemical process, and Chisso, with UOP technology. Four Unipol process PE plants are under construction in China and three are in operation. At Guangzhou, Toyo Engineering is building a 100,000-m.t./year plant, due onstream in 1995, while Snamprogetti is to finish construction of two plants in the same year at Zhonguyan (120,000 m.t./year) and at Maoming (140,000 m.t./year). The Daquing Design Institute is responsible for the engineering of a 60,000-m.t./year Unipol process PE plant, expected onstream early in 1995. Existing Unipol process PE plants are located in Qilu (60,000 m.t./year LLDPE and 120,000 m.t./year HDPE) and at Taching (60,000 m.t./year HDPE)

  16. Remarks on the thorium cycle

    International Nuclear Information System (INIS)

    Teller, E.

    1978-01-01

    The use of thorium and neutrons to make 233 U would provide energy for many thousands of years. Thorium is more abundant than uranium and 233 U is the best fissile material for thermal neutron reactors. Four approaches to the use of thorium are worth developing: heavy water moderated reactors with conversion ratios greater than 0.9, such as modified CANDU with lower cost of separating D 2 O and 235 U; molten salt breeder reactors, from which fission products and excess fuel may be continuously removed; fusion-fission hybrids that produce adequate tritium and excess neutrons for sustenance and 233 U production in a subcritical thorium 233 U blanket; and by fission-initiated thermo-nuclear explosions in cavities in salt beds one mile below the earth's surface, yielding 233 U from the excess neutrons and thorium and decontaminated steam for power production. (author)

  17. Thorium utilisation in thermal reactors

    International Nuclear Information System (INIS)

    Balakrishnan, K.

    1997-01-01

    It is now more or less accepted that the best way to use thorium is in thermal reactors. This is due to the fact that U233 is a good material in the thermal spectrum. Studies of different thorium cycles in various reactor concepts had been carried out in the early days of nuclear power. After three decades of neglect, the world is once again looking at thorium with some interest. We in India have been studying thorium cycles in most of the existing thermal reactor concepts, with greater emphasis on heavy water reactors. In this paper, we report some of the work done in India on different thorium cycles in the Indian pressurized heavy water reactor (PHWR), and also give a description of the design of the advanced heavy water reactor (AHWR). (author). 1 ref., 2 tabs., 5 figs

  18. PRETREATING THORIUM FOR ELECTROPLATING

    Science.gov (United States)

    Beach, J.G.; Schaer, G.R.

    1959-07-28

    A method is presented for pretreating a thorium surface prior to electroplating the surface. The pretreatment steps of the invention comprise cleaning by vapor blasting the surface, anodically pickling in a 5 to 15% by volume aqueous hydrochloric acid bath with a current of 125 to 250 amp/sq ft for 3 to 5 min at room temperature, chemically pickling the surface in a 5 to 15% by volume of aqueous sulfuric acid for 3 to 5 min at room temperature, and rinsing the surface with water.

  19. Contributions to the thorium occupational exposure in Brazil; Contribuicoes ao estudo da exposicao ocupacional ao torio no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Kenya Moore de Almeida Dias da

    1997-12-31

    There are around 15.000 workers in Brazil involved in the mining and milling processes of thorium bearing minerals. It is necessary to estimate the exposure of workers to airborne particulate containing thorium to estimate the risk associated with the inhalation of aerosols. The aims of this study were: - to develop a national cascade impactor and - to characterize the exposure of workers to airborne particulate containing Th in two plants and one industry that were chosen. Plant A and Pant B process niobium ore and industry C uses thorium nitrate to manufacture gas mantle. The national cascade impactor - ICN was developed to collect particulate in the range of 0,64 up to 19,4 {mu}m. Its advantage over commercially available cascade impactors is the selections of particulate in the respirable and inhalable fractions of aerosol. The experimental calibration of the ICN agreed with the theoretical calibration. The results obtained with the ICN were compared to the ones obtained with other selective air samplers, in 3 plants. The particle size distribution and the Th mass concentration were determined in those plants. The size distribution of particulate containing Nb. U Zr, Pb. Fe, Y and Sr, and the elemental mass concentration was determined. A group of workers in installations B and C were also monitored through bioassay analysis of Th excreted in urine and feces. Air and bioassay results have shown that the systemic incorporation of Th is not significant. (author) 116 refs., 37 figs., 31 tabs.

  20. Contributions to the thorium occupational exposure in Brazil; Contribuicoes ao estudo da exposicao ocupacional ao torio no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Kenya Moore de Almeida Dias da

    1998-12-31

    There are around 15.000 workers in Brazil involved in the mining and milling processes of thorium bearing minerals. It is necessary to estimate the exposure of workers to airborne particulate containing thorium to estimate the risk associated with the inhalation of aerosols. The aims of this study were: - to develop a national cascade impactor and - to characterize the exposure of workers to airborne particulate containing Th in two plants and one industry that were chosen. Plant A and Pant B process niobium ore and industry C uses thorium nitrate to manufacture gas mantle. The national cascade impactor - ICN was developed to collect particulate in the range of 0,64 up to 19,4 {mu}m. Its advantage over commercially available cascade impactors is the selections of particulate in the respirable and inhalable fractions of aerosol. The experimental calibration of the ICN agreed with the theoretical calibration. The results obtained with the ICN were compared to the ones obtained with other selective air samplers, in 3 plants. The particle size distribution and the Th mass concentration were determined in those plants. The size distribution of particulate containing Nb. U Zr, Pb. Fe, Y and Sr, and the elemental mass concentration was determined. A group of workers in installations B and C were also monitored through bioassay analysis of Th excreted in urine and feces. Air and bioassay results have shown that the systemic incorporation of Th is not significant. (author) 116 refs., 37 figs., 31 tabs.

  1. Spatial distribution of radionuclides in soil around a coal-fired power plant: lead 210, polonium 210, radium 226, thorium 232, kalium 40 emitted with the fly ash and cesium 137 from the worldwide weapon testing fallout

    Energy Technology Data Exchange (ETDEWEB)

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

    1984-09-01

    To determine the effect of airborne emissions of radionuclides from coal-fired power plants on the environment, the concentrations of the most important radionuclides were measured in soil samples from the local environments (0.4-5.2 km) as well as in fly ash. The spatial distribution of the radionuclides in the soil did not indicate any significantly increased concentrations in the area downwind of the plant compared to other areas; the ratios lead 210/radium 226 and polonium 210/radium 226 were within the range observed for unaffected soils. The emissions from the plant, though present, are obviously too small to significantly change the natural local distribution pattern of the radionuclides in the soil. A highly significant correlation between potassium 40 and thorium 232 was observed which was independent of the different types of soils found in this area. The concentration of cesium 137 in topsoil, which is the result of worldwide fallout from nuclear weapons testing, varied at some places even within a small distance (approx. 2 km) by up to one order of magnitude. Furthermore, it was observed that the concentration of cesium 137 in soils from cropland was on average a factor of 2 less than in those from grassland. This variability has to be considered in planning monitoring programs around nuclear power plants, which may also release this radionuclide. (A.V.)

  2. High precision spectrophotometric analysis of thorium

    International Nuclear Information System (INIS)

    Palmieri, H.E.L.

    1984-01-01

    An accurate and precise determination of thorium is proposed. Precision of about 0,1% is required for the determination of macroquantities of thorium when processed. After an extensive literature search concerning this subject, spectrophotometric titration has been chosen, using dissodium ethylenediaminetetraacetate (EDTA) solution and alizarin-S as indicator. In order to obtain such a precision, an amount of 0,025 M EDTA solution precisely measured has been added and the titration was completed with less than 5 ml of 0,0025 M EDTA solution. It is usual to locate the end-point graphically, by plotting added titrant versus absorbance. The non-linear minimum square fit, using the Fletcher e Powell's minimization process and a computer programme. Besides the equivalence point, other parameters of titration were determined: the indicator concentration, the absorbance of the metal-indicator complex, and the stability constants of the metal-indicator and the metal-EDTA complexes. (Author) [pt

  3. Thorium spectrophotometric analysis with high precision

    International Nuclear Information System (INIS)

    Palmieri, H.E.L.

    1983-06-01

    An accurate and precise determination of thorium is proposed. Precision of about 0,1% is required for the determination of macroquantities of thorium processed. After an extensive literature search concerning this subject, spectrophotometric titration has been chosen, using disodium ethylenediaminetetraacetate (EDTA) solution and alizarin S as indicator. In order to obtain such a precision, an amount of 0,025 M EDTA solution precisely measured has been added and the titration was completed with less than 5 ml of 0,0025 M EDTA solution. It is usual to locate the end-point graphically, by plotting added titrant versus absorbance. The non-linear minimum square fit, using the Fletcher e Powell's minimization process and a computer program. (author)

  4. Basic TRUEX process for Rocky Flats Plant

    International Nuclear Information System (INIS)

    Leonard, R.A.; Chamberlain, D.B.; Dow, J.A.; Farley, S.E.; Nunez, L.; Regalbuto, M.C.; Vandegrift, G.F.

    1994-08-01

    The Generic TRUEX Model was used to develop a TRUEX process flowsheet for recovering the transuranics (Pu, Am) from a nitrate waste stream at Rocky Flats Plant. The process was designed so that it is relatively insensitive to changes in process feed concentrations and flow rates. Related issues are considered, including solvent losses, feed analysis requirements, safety, and interaction with an evaporator system for nitric acid recycle

  5. Separation of thorium (IV) from lanthanide concentrate (LC) and water leach purification (WLP) residue

    International Nuclear Information System (INIS)

    AL-Areqi, Wadeeah M.; Majid, Amran Ab.; Sarmani, Sukiman

    2014-01-01

    Thorium (IV) content in industrial residue produced from rare earth elements production industry is one of the challenges to Malaysian environment. Separation of thorium from the lanthanide concentrate (LC) and Water Leach Purification (WLP) residue from rare earth elements production plant is described. Both materials have been tested by sulphuric acid and alkaline digestions. Th concentrations in LC and WLP were determined to be 1289.7 ± 129 and 1952.9±17.6 ppm respectively. The results of separation show that the recovery of Th separation from rare earth in LC after concentrated sulphuric acid dissolution and reduction of acidity to precipitate Th was found 1.76-1.20% whereas Th recovery from WLP was less than 4% after concentrated acids and alkali digestion processes. Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS) was used to determine Th concentrations in aqueous phase during separation stages. This study indicated that thorium maybe exists in refractory and insoluble form which is difficult to separate by these processes and stays in WLP residue as naturally occurring radioactive material (NORM)

  6. Systematic study on Thorium fuel

    International Nuclear Information System (INIS)

    Shibata, Toshikazu; Kimura, Itsuro; Iwata, Shiro; Furuya, Hirotaka; Suzuki, Susumu.

    1988-01-01

    Introduced is the activities of the Joint Research Project Team on Thorium Fuel organized by mainly university researchers in Japan and supported by the Ministry of Education, Science and Culture for seven years since 1980. Four major groups were organized; (1) nuclear data, reactor physics and design, (2) nuclear fuel, (3) down stream and (4) biological effects of thorium. The first group covered measurements and analysis on nuclear data of thorium related nuclides, experiment and analysis on nuclear characteristics of thorium containing cores, basic engineering on a thorium molten salt reactor, and designs of several types of reactors. Fabrication and irradiation tests of thorium oxide fuel, and basic studies on new type thorium fuels (e.g. carbide and nitride) were studied by the second group. The third group covered the use of solutions in reprocessing of spent fuel, behavior of fission products, immobilization of high level radioactive waste, and continuous reprocessing for a molten salt reactor. The fourth group performed the trace study for patients who had been intravascularly injected with thorotrast for diagnosis of war injuries during the Second World War. (author)

  7. Thoron and associated risks in the handling of thorium compounds; Le thoron et les risques associes dans la manipulation des composes du thorium

    Energy Technology Data Exchange (ETDEWEB)

    Pradel, J; Billard, F [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1959-07-01

    1. Thorium compounds continually give off thoron and its daughters and their radioactivity can constitute a danger for operators who may inhale them. 2. By analogy with radon the maximum admissible content in air of thoron and its daughters has been set at 10{sup -7} {mu}c/cm{sup 3}. However the differences in behaviour between radon and its active deposit on the one hand, and thoron and its daughters on the other, appear great enough to justify more thorough investigation. In fact it seemed probable that, contrary to what takes place with radon, the thoron + thorium A content at a given point may differ appreciable from the thorium B + thorium C + thorium C' + thorium C'' content at the same point, because of the considerable differences in half-life which allow a greater or lesser distribution. 3. To determine the relative concentrations it was necessary to develop a method for estimating thoron in equilibrium with thorium A, the measurement of thorium B and its daughters being carried out in the conventional way by counting the activity collected on a filter. 4. Another object of this study was to estimate the danger presented by thoron in equilibrium with thorium A in the immediate vicinity of thorium sources, in a plant extracting thorium from urano-thorianite. (author) [French] 1. Le thoron et ses descendants se degagent constamment des composes du thorium et leur radioactivite peut presenter un danger pour les personnes qui sont amenees a les respirer. 2. Par analogie avec le radon, la teneur maximum admissible dans l'air de thoron et de ses descendants a ete fixee a 10{sup -7} {mu}c/cm{sup 3}. Mais, les differences de comportement du radon et de son depot actif d'une part, du thoron et de ses descendants d'autre part, ont paru suffisantes pour justifier une etude plus complete. Il semblait en effet probable, contrairement a ce qui se produit pour le radon, qu'en un meme point, la teneur en thoron + thorium A puisse differer notablement de la teneur en

  8. Thoron and associated risks in the handling of thorium compounds; Le thoron et les risques associes dans la manipulation des composes du thorium

    Energy Technology Data Exchange (ETDEWEB)

    Pradel, J.; Billard, F. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1959-07-01

    1. Thorium compounds continually give off thoron and its daughters and their radioactivity can constitute a danger for operators who may inhale them. 2. By analogy with radon the maximum admissible content in air of thoron and its daughters has been set at 10{sup -7} {mu}c/cm{sup 3}. However the differences in behaviour between radon and its active deposit on the one hand, and thoron and its daughters on the other, appear great enough to justify more thorough investigation. In fact it seemed probable that, contrary to what takes place with radon, the thoron + thorium A content at a given point may differ appreciable from the thorium B + thorium C + thorium C' + thorium C'' content at the same point, because of the considerable differences in half-life which allow a greater or lesser distribution. 3. To determine the relative concentrations it was necessary to develop a method for estimating thoron in equilibrium with thorium A, the measurement of thorium B and its daughters being carried out in the conventional way by counting the activity collected on a filter. 4. Another object of this study was to estimate the danger presented by thoron in equilibrium with thorium A in the immediate vicinity of thorium sources, in a plant extracting thorium from urano-thorianite. (author) [French] 1. Le thoron et ses descendants se degagent constamment des composes du thorium et leur radioactivite peut presenter un danger pour les personnes qui sont amenees a les respirer. 2. Par analogie avec le radon, la teneur maximum admissible dans l'air de thoron et de ses descendants a ete fixee a 10{sup -7} {mu}c/cm{sup 3}. Mais, les differences de comportement du radon et de son depot actif d'une part, du thoron et de ses descendants d'autre part, ont paru suffisantes pour justifier une etude plus complete. Il semblait en effet probable, contrairement a ce qui se produit pour le radon, qu'en un meme point, la teneur en thoron + thorium A puisse

  9. Thorium oxalate solubility and morphology

    International Nuclear Information System (INIS)

    Monson, P.R. Jr.; Hall, R.

    1981-10-01

    Thorium was used as a stand-in for studying the solubility and precipitation of neptunium and plutonium oxalates. Thorium oxalate solubility was determined over a range of 0.001 to 10.0 in the concentration parameter [H 2 C 2 O 4 ]/[HNO 3 ] 2 . Morphology of thorium oxide made from the oxalate precipitates was characterized by scanning electron microscopy. The different morphologies found for oxalate-lean and oxalate-rich precipitations were in agreement with predictions based on precipitation theory

  10. Thorium fuels for heavy water reactors. Romanian experience

    International Nuclear Information System (INIS)

    Glodeanu, F.; Mirion, I.; Mehedinteanu, S.; Balan, V.

    1984-01-01

    The renewed interest in thorium fuel cycle due to the increased demand for fissile materials has resulted in speeding up the related research and development activities. For heavy water reactors the thorium cycles, especially SSET, are very promising and many efforts are made to demonstrate their feasibility. In our country, at INPR, the research and development activity has been initiated in the following areas: the conceptual design of thorium bearing fuel elements; fuel modelling; nuclear grade thorium dioxide powder technology; mixed oxide fuel technology. In the design area, the key factors in performance limitation, especially at extended burnup have been accounted and different remedies proposed. An irradiation programme has been settled and will start this year. The modelling activities are focused on mixed oxide behaviour and material data measurements are in progress. In the nuclear grade thorium powder technology area, a good piece of work has been done to develop an integrated technology for monasite processing (thorium being a by-product in lanthanides extraction). As regards the mixed oxide fuel technology, efforts have been made to obtain (ThU)O 2 pellets with good homogeneity and high density at different compositions. Besides the mixing powders route, other non-conventional technologies for refabrication like: microspheres, pellet impregnation and clay extrusion are studied. Experimental fuel rods for irradiation testing have been manufactured. (author)

  11. The possibility of precipitating thorium soap from aqueous solutions

    International Nuclear Information System (INIS)

    Drathen, H.

    1975-01-01

    The purpose of the analysis was firstly to determine the precipitation process of thorium with soap and the influence of foreign ions, secondly to explain the conditions for the best method of decontaminating waste waters contaminated by thoriuum. The result was that if thorium is precipitated with soap both thorium soaps and thorium hydroxide are formed. The proportion of each substance depends considerably upon the pH value. All the precipitation compounds exist independently. No adsorption or mixed crystal formation took place. By adding bivalent or multivalent cations the one-step decontamination factor increases to more than 20. Quantitatively, the decontamination of thorium contaminated waste waters can be carried out down to a thorium concentration of 10 -5 mol/1. Technical soaps provide the least expensive solution without displaying any qualitative disadvantages. The only disadvantage is that this method cannot be used continuously. Therefore ion exchangers provide a great advantage, although they are very expensive and have a limited capacity. The best solution, then, is a combination of ion exchangers and precipitation with soap. (orig.) [de

  12. Historical and perspectives of thorium compounds production and purification at IPEN-CNEN/SP

    International Nuclear Information System (INIS)

    Lainetti, Paulo E.O.; Abrao, A.; Freitas, Antonio A.; Carvalho, Fatima M.S. de; Bergamaschi, Vanderlei S.; Cunha, Edgar F.; Ayoub, Jamil M.S.; Mindrisz, Ana C.

    2000-01-01

    The production and purification of some thorium compounds has been performed in the IPEN in the last 15 years. Some raw materials have been employed in this production, obtained from the monazite exploitation in industrial scale that it was performed in Sao paulo during the period 1948 until 1994. More than 160 t of high purity thorium nitrate were produced, purified by the solvent extraction process. The thorium nitrate has been supplied for the Brazilian portable gaslight industry to the production of Welsbach Mantle. Nowadays, a new facility is being designed and built. The main concern is the recovering of the production capacity, lost after some years of operation without suitable maintenance. This activity has an important strategic role, considering the huge Brazilian thorium resources and the renewed interest in thorium fuel cycle. This paper describes a brief historical background of thorium activities in the IPEN as well as their perspectives. (author)

  13. Sustainability: role of thorium

    International Nuclear Information System (INIS)

    Stigson, Bjorn Roland

    2015-01-01

    The task to renew the world's energy infrastructure, where fossil fuels account for 80% of supply, is enormous. The two carbon neutral energy sources - renewable and nuclear - should be the base of the world's future energy mix. Nuclear, however, suffers from a bad public opinion and lack of government support in many parts of the world. We can conclude that the world needs an 'on demand' energy source that is affordable, clean, safe and scalable. Thorium energy could be that energy source. It is the most energy dense solution we know, fitting well to the modular and size-constrained requirements of an urbanizing world. No part of society can create a sustainable world on their own and markets are too slow to drive transformational changes. We need new partnerships between governments, business, civil society and academia where each part is delivering on their specific responsibilities and roles

  14. Springfield Processing Plant (SPP) Facility Information

    Energy Technology Data Exchange (ETDEWEB)

    Leach, Janice; Torres, Teresa M.

    2012-10-01

    The Springfield Processing Plant is a hypothetical facility. It has been constructed for use in training workshops. Information is provided about the facility and its surroundings, particularly security-related aspects such as target identification, threat data, entry control, and response force data.

  15. Sorption behaviour of uranium and thorium on cryptomelane-type hydrous manganese dioxide from aqueous solution

    International Nuclear Information System (INIS)

    El-Naggar, I.M.; El-Absy, M.A.; Abdel-Hamid, M.M.; Aly, H.F.

    1993-01-01

    The kinetics of sorption of uranium and thorium from aqueous nitrate solutions on cryptomelane-type hydrous manganese dioxide (CRYMO) was studied. The exchange of uranium is particle diffusion controlled while that of thorium is chemical reaction at the exchange sites. Sorption of uranium and thorium by CRYMO has been also studied as a function of metal concentrations and temperature. The sorption of both cations is found to be an endothermic process and increases markedly with temperature between 30 and 60 degree C. The sorption results have been analysed by the langmuir adsorption isotherm over the entire range of uranium and thorium concentrations investigated. 35 refs., 8 figs., 5 tabs

  16. Magellanic Clouds Cepheids: Thorium Abundances

    Directory of Open Access Journals (Sweden)

    Yeuncheol Jeong

    2018-03-01

    Full Text Available The analysis of the high-resolution spectra of 31 Magellanic Clouds Cepheid variables enabled the identification of thorium lines. The abundances of thorium were found with spectrum synthesis method. The calculated thorium abundances exhibit correlations with the abundances of other chemical elements and atmospheric parameters of the program stars. These correlations are similar for both Clouds. The correlations of iron abundances of thorium, europium, neodymium, and yttrium relative to the pulsational periods are different in the Large Magellanic Cloud (LMC and the Small Magellanic Cloud (SMC, namely the correlations are negative for LMC and positive or close to zero for SMC. One of the possible explanations can be the higher activity of nucleosynthesis in SMC with respect to LMC in the recent several hundred million years.

  17. Guide to the conduct of public meetings as part of the public information process for uranium and thorium mine-mill facilities

    International Nuclear Information System (INIS)

    1980-01-01

    The Canadian Atomic Energy Control Board requires that an applicant for a site approval for a uranium or thorium mine-mill facility inform the public about the project and facilitate public response. For small undertakings, the information requirement may be met by a public meeting organized by the proponents of the project. This guide provides specific instructions on giving notice of the meeting, availability of documentation, choice of a chairperson, agenda, the roles of the proponents and the regulatory agencies, and means of obtaining feedback from the public. (L.L.)

  18. Ranstad - A new uranium-processing plant

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, A [AB Atomenergi, Stockholm (Sweden)

    1967-06-15

    A short outline is given of the decisions concerning the erection and operation of the Ranstad mill which was recently taken into operation. It is followed by a brief description of the geological conditions and the planning of the mining system, plant location, and the factory. The main part of the paper describes processes and equipment of the plant which has a capacity to treat approx. 850 000 tons of low-grade ore (alum shale) per year. The operational experience so far is also reviewed. The economy of uranium production at Ranstad is discussed and some development possibilities are indicated. (author)

  19. Waste processing system for nuclear power plant

    International Nuclear Information System (INIS)

    Higashinakagawa, Emiko; Tezuka, Fuminobu; Maesawa, Yukishige; Irie, Hiromitsu; Daibu, Etsuji.

    1996-01-01

    The present invention concerns a waste processing system of a nuclear power plant, which can reduce the volume of a large amount of plastics without burying them. Among burnable wastes and plastic wastes to be discarded in the power plant located on the sea side, the plastic wastes are heated and converted into oils, and the burnable wastes are burnt using the oils as a fuel. The system is based on the finding that the presence of Na 2 O, K 2 O contained in the wastes catalytically improves the efficiency of thermal decomposition in a heating atmosphere, in the method of heating plastics and converting them into oils. (T.M.)

  20. Thorium in the workplace measurement intercomparison

    International Nuclear Information System (INIS)

    Modna, D.K.; Jerome, S.M.; White, M.A.; Woods, M.J.

    2000-01-01

    The monitoring of radionuclides in the nuclear industry has been recognized as the most straightforward way of assessing health and safety issues associated with the exposure of the workforce to potentially harmful radiation doses. Much of this is achieved by measurements in the workplace itself and by the bioassay and monitoring of workers in the industry. However, there also exists a significant 'non-nuclear' industry where workers are exposed to radioactive materials, for example where this involves thorium, which is made wide use of in the aerospace and other high technology industries. As such work involves the processing of thorium bearing materials, the workforce is potentially exposed to 232 Th and its daughter nuclides. Thus, to monitor the workforce effectively, it is important to be able to measure both 232 Th and the decay products of 232 Th where they are in an unknown state of radioactive equilibrium and this is where monitoring laboratories may experience some difficulty. Accordingly, the Health and Safety Laboratory in the UK has organized a EC wide project on the monitoring of thorium in the 'non-nuclear' workplace; this project is currently ongoing. We report the results of the first intercomparison of this project involving two solutions of 232 Th, one in radioactive equilibrium and one not in equilibrium with its daughters. The results are presented with some comments on how this intercomparison has progressed and how these first results will inform the rest of the project

  1. Decontamination process applied to radioactive solid wastes from nuclear power plants

    International Nuclear Information System (INIS)

    Franco, Milton B.; Kastner, Geraldo F.; Monteiro, Roberto Pellacani G.

    2009-01-01

    The process of decontamination is an important step in the economic operation of nuclear facilities. A large number of protective clothing, metallic parts and equipment get contaminated during the handling of radioactive materials in laboratory, plants and reactors. Safe and economic operation of these nuclear facilities will have a bearing on the extent to which these materials are reclaimed by the process of decontamination. The most common radioactive contaminants are fission products, corrosion products, uranium and thorium. The principles involved in decontamination are the same as those for an industrial cleaning process. However, the main difference is in the degree of cleaning required and at times special techniques have to be employed for removing even trace quantities of radioactive materials. This paper relate decontaminations experiences using acids and acids mixtures (HCl, HF, HNO 3 , KMnO 4 , C 2 H 2 O 4 , HBF 4 ) in several kinds of radioactive solid wastes from nuclear power plants. The result solutions were monitored by nuclear analytical techniques, in order to contribute for radiochemical characterization of these wastes. (author)

  2. Current extraction and separation of uranium, thorium and rare earths elements from monazite leach solution using organophosphorous extractants

    International Nuclear Information System (INIS)

    Biswas, Sujoy; Rupawate, V.H.; Hareendran, K.N.; Roy, S.B.

    2014-01-01

    A new process based on solvent extraction has been developed for separation of uranium, thorium and rare earths from monazite leach solution using organophosphorous extractants. The Thorium cake coming from monazite source was dissolved in HNO 3 medium in presence of trace amount of HF for feed preparation. The separation of U(VI) was carried out by liquid-liquid extraction using tris-2-ethyl hexyl phosphoric acid (TEHP) in dodecane leaving thorium and rare earths elements in the raffinate. The thorium from raffinate was selectively extracted using 1M tri iso amyl phosphate (TiAP) in dodecane in organic phase leaving all rare earths elements in aqueous solution. The uranium and thorium from organic medium was quantitatively stripped using 0.05 M HNO 3 counter current mode. Results indicate the quantitative separation of uranium, thorium and rare earths from thorium cake (monazite source) using organophosphorous extractant in counter current mode

  3. Pinellas Plant facts. [Products, processes, laboratory facilities

    Energy Technology Data Exchange (ETDEWEB)

    1986-09-01

    This plant was built in 1956 in response to a need for the manufacture of neutron generators, a principal component in nuclear weapons. The neutron generators consist of a miniaturized linear ion accelerator assembled with the pulsed electrical power supplies required for its operation. The ion accelerator, or neutron tube, requires ultra clean, high vacuum technology: hermetic seals between glass, ceramic, glass-ceramic, and metal materials: plus high voltage generation and measurement technology. The existence of these capabilities at the Pinellas Plant has led directly to the assignment of the lightning arrester connector, specialty capacitor, vacuum switch, and crystal resonator. Active and reserve batteries and the radioisotopically-powered thermoelectric generator draw on the materials measurement and controls technologies which are required to ensure neutron generator life. A product development and production capability in alumina ceramics, cermet (electrical) feedthroughs, and glass ceramics has become a specialty of the plant; the laboratories monitor the materials and processes used by the plant's commercial suppliers of ferroelectric ceramics. In addition to the manufacturing facility, a production development capability is maintained at the Pinellas Plant.

  4. Alarm-Processing in Nuclear Power Plants

    International Nuclear Information System (INIS)

    Otazo, J; Fernandez, R

    2000-01-01

    Information overload due to the activation of a great number of alarms in a short time is a common problem for the operator in the control room of a industrial plant, mainly in complex process like the nuclear power plants.The problem is the conventional conception of the alarm system, that defines each alarm like a separated and independent entity of the global situation of the plant.A direct consequence is the generation of multiple alarms during a significative disturbance in the process, being most of them redundant and irrelevant to the actual process state wich involves an extra load to the operator, who wastes time in acting selecting the important alarms of the group that appears or lead to a an erroneous action.The present work first describes the techniques developed in the last years to attack the avalanche of alarms problem.Later we present our approach to alarm-processing: an expert system as alarm-filter.Our objective is collect in the system the state of the art in the development of advanced alarm systems, offering an improvement of the information flow to the operators through the suppression of nonsignificant alarms and a structured visualization of the process state.Such support is important during a disturbance for the identification of plant state, diagnosis, consequence prediction and corrective actions.The system is arranged in three stages: alarm-generation, alarm-filter and alarm-presentation.The alarm-generation uses conventional techniques or receives them from an external system.The alarm-filter uses suppression techniques based on: irrelevance analysis with the operation mode and the state of components, causal reasoning and static importance analysis.The alarm presentation is made through a structured way using a priority scheme with three level.The knowledge representation of each alarm is based on frames and a graph of alarms for global knowledge, where the connections between nodes represent causal and irrelevance relations

  5. Defense Waste Processing Facility, Savannah River Plant

    International Nuclear Information System (INIS)

    After 10 years of research, development, and testing, the US Department of Energy is building a new facility which will prepare high-level radioactive waste for permanent disposal. The Defense Waste Processing Facility, known as the DWPF, will be the first production-scale facility of its kind in the United States. In the DWPF, high-level waste produced by defense activities at the Savannah River Plant will be processed into a solid form, borosilicate glass, suitable for permanent off-site geologic disposal. With construction beginning in the fall of 1983, the DWPT is scheduled to be operational in 1989. By 2005, the DWPF will have immobilized the backlog of high-level waste which has been accumulating in storage tanks at the Savannah River Plant since 1954. Canisters of the immobilized waste will then be ready for permanent disposal deep under the ground, safely isolated from the environment

  6. The uranium and thorium separation in the chemical reprocessing of the irradiated fuel of thorium and uranium mixed oxides

    International Nuclear Information System (INIS)

    Oliveira, E.F. de.

    1984-09-01

    A bibliographic research has been carried out for reprocessing techniques of irradiated thorium fuel from nuclear reactors. The Thorex/Hoechst process has been specially considered to establish a method for reprocessing thorium-uranium fuel from PWR. After a series of cold tests performed in laboratory it was possible to set the behavior of several parameters affecting the Thorex/Hoechst process. Some comments and suggestions are presented for modifications in the process flosheet conditions. A discussion is carried out for operational conditions such as the aqueous to organic flow ratio the acidity of strip and scrub solutions in the process steps for thorium and uranium recovery. The operation diagrams have been constructed using equilibrium experimental data which correspond to conditions observed in laboratory. (Author) [pt

  7. AIRBORNE MICROORGANISMS IN BROILER PROCESSING PLANTS.

    Science.gov (United States)

    KOTULA, A W; KINNER, J A

    1964-05-01

    Concentrations of total aerobic bacteria, molds, yeasts, coliforms, enterococci, and psychrophiles were determined in the air of two poultry processing plants with Andersen samplers and a mobile power supply. Total aerobic bacterial counts were highest in the dressing room, with diminishing numbers in the shackling, eviscerating, and holding rooms, when sampling was carried out during plant operation. The average counts per ft(3) of air in these four rooms were 2,200; 560; 230; and 62, respectively. (Each value is the average of 36 observations.) The number of organisms increased in the shackling and dressing rooms once processing was begun. Average total aerobic bacterial counts increased from 70 to 870 to 3,000 in the shackling room and from 310 to 4,900 to 7,000 in the dressing room when sampling was carried out at 5:00 am (before plant operations), 9:00 am, and 2:00 pm, respectively. (Each value is the mean of 12 observations.) Airborne molds might originate from a source other than the poultry being processed.

  8. Biorefinery plant design, engineering and process optimisation

    DEFF Research Database (Denmark)

    Holm-Nielsen, Jens Bo; Ehimen, Ehiazesebhor Augustine

    2014-01-01

    Before new biorefinery systems can be implemented, or the modification of existing single product biomass processing units into biorefineries can be carried out, proper planning of the intended biorefinery scheme must be performed initially. This chapter outlines design and synthesis approaches...... applicable for the planning and upgrading of intended biorefinery systems, and includes discussions on the operation of an existing lignocellulosic-based biorefinery platform. Furthermore, technical considerations and tools (i.e., process analytical tools) which could be applied to optimise the operations...... of existing and potential biorefinery plants are elucidated....

  9. TBP production plant effluent treatment process

    International Nuclear Information System (INIS)

    Sriniwas, C.; Sugilal, G.; Wattal, P.K.

    2004-06-01

    TBP production facility at Heavy Water Plant, Talcher generates about 2000 litres of effluent per 200 kg batch. The effluent is basically an aqueous solution containing dissolved and dispersed organics such as dibutyl phosphate, butanol etc. The effluent has high salinity, chemical oxygen demand (30-80 g/L) and pungent odour. It requires treatment before discharge. A chemical precipitation process using ferric chloride was developed for quantitative separation of organics from the aqueous part of the effluent. This process facilitates the discharge of the aqueous effluent. Results of the laboratory and bench scale experiments on actual effluent samples are presented in this report. (author)

  10. Establishing bounding internal dose estimates for thorium activities at Rocky Flats.

    Science.gov (United States)

    Ulsh, Brant A; Rich, Bryce L; Chew, Melton H; Morris, Robert L; Sharfi, Mutty; Rolfes, Mark R

    2008-07-01

    As part of an evaluation of a Special Exposure Cohort petition filed on behalf of workers at the Rocky Flats Plant, the National Institute for Occupational Safety and Health (NIOSH) was required to demonstrate that bounding values could be established for radiation doses due to the potential intake of all radionuclides present at the facility. The main radioactive elements of interest at Rocky Flats were plutonium and uranium, but much smaller quantities of several other elements, including thorium, were occasionally handled at the site. Bounding potential doses from thorium has proven challenging at other sites due to the early historical difficulty in detecting this element through urinalysis methods and the relatively high internal dose delivered per unit intake. This paper reports the results of NIOSH's investigation of the uses of thorium at Rocky Flats and provides bounding dose reconstructions for these operations. During this investigation, NIOSH reviewed unclassified reports, unclassified extracts of classified materials, material balance and inventory ledgers, monthly progress reports from various groups, and health physics field logbooks, and conducted interviews with former Rocky Flats workers. Thorium operations included: (1) an experimental metal forming project with 240 kg of thorium in 1960; (2) the use of pre-formed parts in weapons mockups; (3) the removal of Th from U; (4) numerous analytical procedures involving trace quantities of thorium; and (5) the possible experimental use of thorium as a mold coating compound. The thorium handling operations at Rocky Flats were limited in scope, well-monitored and documented, and potential doses can be bounded.

  11. Spallation symbiont and thorium breeding

    International Nuclear Information System (INIS)

    Furukawa, Kazuo

    1991-01-01

    The medium term world energy and environment countermeasures for 2020-2070 are not yet clearly established. The forecast of energy situation hereafter, its problems and the measures for solution are considered. World trend is removing borders, and the north-south problems are increasing the importance. The rational and clear idea with the support of concrete technology is required. The demand of energy will increase enormously at the annual rate of 2.3%. The world energy situation was forecast considering the increase of population, and it will be 115 TW at the end of the next century. The present status, problems and the countermeasures in nuclear fission energy technology are explained. The countermeasures should be based on three principles, namely Th-U-233 cycle, the utilization of molten fluoride fuel medium and the separation of molten salt breeders and molten salt reactors. Accelerator molten salt breeders, small molten salt reactors, the nuclear fuel cycle and the annihilation process for radioactive wastes are reported. The perspective that the nuclear energy system, in which the reactor safety, the measures to wastes and others are improved by the spallation-fission symbiont using thorium molten salt as the working medium, can be constructed is shown. (K.I.)

  12. Uranium and thorium recovery in thorianite ore-preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Gaiotte, Joao V.M. [Universidade Federal de Alfenas, Pocos de Caldas, MG (Brazil); Villegas, Raul A.S.; Fukuma, Henrique T., E-mail: rvillegas@cnen.gov.br, E-mail: htfukuma@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Pocos de Caldas, MG (Brazil). Lab. de Pocos de Caldas

    2011-07-01

    This work presents the preliminary results of the studies aiming to develop a hydrometallurgical process to produce uranium and thorium concentrates from thorianite ore from Amapa State, Brazil. This process comprises two major parts: acid leaching and Th/U recovery using solvent extraction strategies. Thorianite ore has a typical composition of 60 - 70% of thorium, 8 - 10% lead and 7 - 10% uranium. Sulfuric acid leaching operational conditions were defined as follows: acid/ore ratio 7.5 t/t, ore size below 65 mesh (Tyler), 2 hours leaching time and temperature of 100 deg C. Leaching tests results showed that uranium and thorium recovery exceeded 95%, whereas 97% of lead ore content remained in the solid form. Uranium and thorium simultaneous solvent extraction is necessary due to high sulfate concentration in the liquor obtained from leaching, so the Primene JM-T primary anime was used for this extraction step. Aqueous raffinate from extraction containing sulfuric acid was recycled to the leaching step, reducing acid uptake around 60%, to achieve a net sulfuric acid consumption of 3 t/t of ore. Uranium and thorium simultaneous stripping was performed using sodium carbonate solution. In the aqueous stripped it was added sulfuric acid at pH 1.5, followed by a second solvent extraction step using the tertiary amine Alamine 336. The following stripping step was done with a solution of sodium chloride, resulting in a final solution of 23 g L-1 uranium. (author)

  13. Drying characteristics of thorium fuel corrosion products

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.-E. E-mail: rzl@inel.gov

    2004-07-01

    The open literature and accessible US Department of Energy-sponsored reports were reviewed for the dehydration and rehydration characteristics of potential corrosion products from thorium metal and thorium oxide nuclear fuels. Mixed oxides were not specifically examined unless data were given for performance of mixed thorium-uranium fuels. Thorium metal generally corrodes to thorium oxide. Physisorbed water is readily removed by heating to approximately 200 deg. C. Complete removal of chemisorbed water requires heating above 1000 deg. C. Thorium oxide adsorbs water well in excess of the amount needed to cover the oxide surface by chemisorption. The adsorption of water appears to be a surface phenomenon; it does not lead to bulk conversion of the solid oxide to the hydroxide. Adsorptive capacity depends on both the specific surface area and the porosity of the thorium oxide. Heat treatment by calcination or sintering reduces the adsorption capacity substantially from the thorium oxide produced by metal corrosion.

  14. Thorium Energy for the World

    CERN Document Server

    Revol, Jean-Pierre; Bourquin, Maurice; Kadi, Yacine; Lillestol, Egil; De Mestral, Jean-Christophe; Samec, Karel

    2016-01-01

    The Thorium Energy Conference (ThEC13) gathered some of the world’s leading experts on thorium technologies to review the possibility of destroying nuclear waste in the short term, and replacing the uranium fuel cycle in nuclear systems with the thorium fuel cycle in the long term. The latter would provide abundant, reliable and safe energy with no CO2 production, no air pollution, and minimal waste production. The participants, representatives of 30 countries, included Carlo Rubbia, Nobel Prize Laureate in physics and inventor of the Energy Amplifier; Jack Steinberger, Nobel Prize Laureate in physics; Hans Blix, former Director General of the International Atomic Energy Agency (IAEA); Rolf Heuer, Director General of CERN; Pascal Couchepin, former President of the Swiss Confederation; and Claude Haegi, President of the FEDRE, to name just a few. The ThEC13 proceedings are a source of reference on the use of thorium for energy generation. They offer detailed technical reviews of the status of thorium energy ...

  15. Transformation using peroxide of a crude thorium hydroxide in nitrate for mantle grade

    International Nuclear Information System (INIS)

    Freitas, Antonio Alves de; Carvalho, Fatima Maria Sequeira de; Ferreira, Joao Coutinho; Abrao, Alcidio

    2002-01-01

    An alternative process for the recovery and purification of thorium starting from a crude thorium hydroxide as the precursor is outlined in this paper. Its composition is 60.1% thorium oxide (ThO 2 ), 18.6% rare earth oxides (TR 2 O 3 ), and common impurities like silicium, iron, titanium, lead and sodium. This material was produced industrially from the monazite processing in Brazil and has been stocked since several years. The crude thorium hydroxide is treated with hot nitric acid and after the digestion and addition of floculant it is filtered for the separation of the insoluble fraction. Using this nitrate solution, the thorium peroxide is precipitated after adjustment of pH and controlled addition of hydrogen peroxide. The final thorium peroxide is dissolved with nitric acid and the resulting thorium nitrate is mantle grade quality. Rare earth elements are recovered from the thorium peroxide filtrate. The main process parameters for the peroxide precipitation, like pH and temperature and main the results are presented and discussed. (author)

  16. The economics of thorium fuel cycles

    International Nuclear Information System (INIS)

    James, R.A.

    1978-01-01

    The individual cost components and the total fuel cycle costs for natural uranium and thorium fuel cycles are discussed. The thorium cycles are initiated by using either enriched uranium or plutonium. Subsequent thorium cycles utilize recycled uranium-233 and, where necessary, either uranium-235 or plutonium as topping. A calculation is performed to establish the economic conditions under which thorium cycles are economically attractive. (auth)

  17. Determination of sulfate in thorium salts using gravimetric technique with previous thorium separation

    International Nuclear Information System (INIS)

    Silva, C.M. da; Pires, M.A.F.

    1994-01-01

    Available as short communication only. A simple analytical method to analyze sulfates in thorium salt, is presented. The method is based on the thorium separation as hydroxide. The gravimetric technique is used to analyze the sulfate in the filtered as barium sulfate. Using this method, the sulfate separation from thorium has been reach 99,9% yield, and 0,1% precision. This method is applied to thorium salts specifically thorium sulfate, carbonate and nitrate. (author). 5 refs, 2 tabs

  18. Recovery of thorium along with uranium 233 from Thorex waste solution employing Chitosan

    International Nuclear Information System (INIS)

    Priya, S.; Reghuram, D.; Kumaraguru, K.; Vijayan, K.; Jambunathan, U.

    2003-01-01

    The low level waste solution, generated from Thorex process during the processing of U 233 , contains thorium along with traces of Th 228 and U 233 . Chitosan, a natural bio-polymer derived from Chitin, was earlier used to recover the uranium and americium. The studies were extended to find out its thorium sorption characteristics. Chitosan exhibited very good absorption of thorium (350 mg/g). Chitosan was equilibrated directly with the low level waste solution at different pH after adjusting its pH, for 60 minutes with a Chitosan to aqueous ratio of 1:100 and the raffinates were filtered and analysed. The results showed more than 99% of thorium and U 233 could be recovered by Chitosan between pH 4 and 5. Loaded thorium and uranium could be eluted from the Chitosan by 1M HNO 3 quantitatively. (author)

  19. Hodgkin's disease following thorium dioxide angiography

    Energy Technology Data Exchange (ETDEWEB)

    Gotlieb, A I; Kirk, M E [McGill Univ., Montreal, Quebec (Canada). Dept. of Pathology; Hutchison, J L [Montreal General Hospital, Quebec (Canada)

    1976-09-04

    Hodgkin's disease occurred in a 53-year-old man who, 25 years previously, had undergone cerebral angiography, for which thorium dioxide suspension (Thorotrast) was used. Deposits of thorium dioxide were noted in reticuloendothelial cells in various locations. An association between thorium dioxide administration and the subsequent development of malignant tumours and neoplastic hematologic disorders has previously been reported.

  20. Advanced thorium cycles in LWRs and HWRs

    International Nuclear Information System (INIS)

    Radkowsky, A.

    The main aspects of advanced thorium cycles in LWRs and HWRs are reviewed. New concepts include the seed blanket close packed heavy water breeder, the light water seed blanket thorium burner and self-induced thorium cycle in CANDU type reactors. (author)

  1. Determination of natural thorium in urines

    International Nuclear Information System (INIS)

    Jeanmaire, L.; Jammet, H.

    1959-01-01

    A procedure for the quantitative analysis of thorium in urine is described. After precipitation with ammonium hydroxide, dissolution of the precipitate, extraction at pH 4-4.2 with cupferron in chloroformic solution and mineralization, a colorimetric determination of thorium with thorin is performed. It is thus possible to detect about 2 γ of thorium in the sample. (author) [fr

  2. New nuclear plant design and licensing process

    International Nuclear Information System (INIS)

    Luangdilok, W.

    1996-01-01

    This paper describes latest developments in the nuclear power reactor technology with emphasis on three areas: (1) the US technology of advanced passive light water reactors (AP600 and S BWR), (2) regulatory processes that certify their safety, and (3) current engineering concerns. The goal is to provide and insight of how the government's regulatory agency guarantees public safety by looking into how new passive safety features were designed and tested by vendors and how they were re-evaluated and retested by the US NRC. The paper then discusses the US 1989 nuclear licensing reform (10 CFR Part 52) whose objectives are to promote the standardization of nuclear power plants and provide for the early and definitive resolution of site and design issues before plants are built. The new licensing process avoids the unpredictability nd escalated construction cost under the old licensing process. Finally, the paper summarizes engineering concerns found in current light water reactors that may not go away in the new design. The concerns are related the material and water chemistry technology in dealing with corrosion problems in water-cooled nuclear reactor systems (PWRs and BWRs). These engineering concerns include core shroud cracking (BWRs), jet pump hold-down beam cracking (BWRs), steam generator tube stress corrosion cracking (PWR)

  3. Extractive spectrophotometric determination of thorium

    International Nuclear Information System (INIS)

    Venkatesan, M.; Gopalakrishnan, V.; Ramanujam, A.; Nadkarni, M.N.

    1981-01-01

    An extractive spectrophotometric method has been standardized for the analysis of 0.2 to 1.6 milligrams of thorium present in nitric acid solutions. The method involves the extraction of thorium from nitric acid solutions into 0.5 M thenoyl trifluoro acetone (HTTA) in benzene and its direct estimation from the organic extract by spectrophotometry as Thoron colour complex. In this method, interference due to iron upto 5 milligrams can be suppressed by adding ascorbic acid in the ratio of 1:2 prior to HTTA extraction. Uranium(VI) does not interefere even when present in 2000 times the amount of thorium. Plutonium and cerium do not interfere at one milligram level whereas zirconium interferes in this method. The overall error variation and precision of this method has been determined to be +- 3.5%. (author)

  4. Potential of thorium use in the HTR reactor

    International Nuclear Information System (INIS)

    Engelmann, P.; Hansen, U.; Kolb, G.; Leushacke, D.; Teuchert, E.; Werner, H.

    1979-08-01

    In this investigation, several types of reactors and fuel circulations are dealt with as they refer to the region of the Federal Republic of Germany and are compared with each other as to their need for uranium and their costs until 2100. This includes also an investigation covering the effects of a postponed application of uranium-saving reactors, a delayed reprocessing and two variants of the nuclear energy's contribution to electricity generation. After today's light water reactor (LWR) of the pressure water reactor type (DWR) and the sodium-cooled fast breeder (SBR) which is being developed, the technically rather developed helium-cooled high temperature reactor (HTR) is dealt with as another system. The high temperature reactor is, because of its high coolant temperatures, not only suitable as a nuclear power plant, but can also be used to substitute fossile energy sources on the heat market and is being developed in Germany also for use as process heat reactor for nuclear coal gasification. Here the application of nuclear energy is only considered with regard to the region of power generation. Besides the case of the LWR and HTR-operation without reprocessing and fuel recycling for all reactor systems, the calculations also take into consideration the case of the closed fuel recycling. While LWR and SBR are based on the uranium-plutonium-fuel recycling, the thorium-uranium fuel circulation is considered for the HTR with globular fuel elements. As investigations made until today are generally restricted to the system LWR/SBR and the uranium-plutonium circulation, a main concern of the investigations presented here is to show the potential of the Thorium-utilization in high-temperature reactors and to determine how this system can also be applied during the time period concerned to set up a nuclear energy strategy which is safe and profitable as far as the uranium supply is concerned. (orig./UA) 891 UA/orig.- 892 HIS [de

  5. Energy optimization of integrated process plants

    Energy Technology Data Exchange (ETDEWEB)

    Sandvig Nielsen, J

    1996-10-01

    A general approach for viewing the process synthesis as an evolutionary process is proposed. Each step is taken according to the present level of information and knowledge. This is formulated in a Process Synthesis Cycle. Initially the synthesis is conducted at a high abstraction level maximizing use of heuristics (prior experience, rules of thumbs etc). When further knowledge and information are available, heuristics will gradually be replaced by exact problem formulations. The principles in the Process Synthesis Cycle, is used to develop a general procedure for energy synthesis, based on available tools. The procedure is based on efficient use of process simulators with integrated Pinch capabilities (energy targeting). The proposed general procedure is tailored to three specific problems (Humid Air Turbine power plant synthesis, Nitric Acid process synthesis and Sulphuric Acid synthesis). Using the procedure reduces the problem dimension considerable and thus allows for faster evaluation of more alternatives. At more detailed level a new framework for the Heat Exchanger Network synthesis problem is proposed. The new framework is object oriented based on a general functional description of all elements potentially present in the heat exchanger network (streams, exchangers, pumps, furnaces etc.). (LN) 116 refs.

  6. Study of the thorium incorporation by inhalation in individuals occupationally exposed

    International Nuclear Information System (INIS)

    Holanda e Vasconcellos Carvalho, B. de.

    1983-01-01

    A mathematical model describing the metabolism of inhaled thorium in the human body was developed. Through this model theoretical limits of excretion were calculated for workers of a monazite plant (Usina Santo Amaro). This limits were based on International Commission on Radiological Protection publication 30, 1979. Excreta samples from twelve workers of Usina Santo Amaro were collected and analysed for thorium. All samples were bellow the theoretical limits of excretion indicating that Usina Santo Amaro workers are exposed to thorium levels bellow the Annual Limits of Intake recommended by ICRP, publication 30. (author)

  7. Idaho Chemical Processing Plant Site Development Plan

    International Nuclear Information System (INIS)

    Ferguson, F.G.

    1994-02-01

    The Idaho Chemical Processing Plant (ICPP) mission is to receive and store spent nuclear fuels and radioactive wastes for disposition for Department of Energy (DOE) in a cost-effective manner that protects the safety of Idaho National Engineering Laboratory (INEL) employees, the public, and the environment by: Developing advanced technologies to process spent nuclear fuel for permanent offsite disposition and to achieve waste minimization. Receiving and storing Navy and other DOE assigned spent nuclear fuels. Managing all wastes in compliance with applicable laws and regulations. Identifying and conducting site remediation consistent with facility transition activities. Seeking out and implementing private sector technology transfer and cooperative development agreements. Prior to April 1992, the ICPP mission included fuel reprocessing. With the recent phaseout of fuel reprocessing, some parts of the ICPP mission have changed. Others have remained the same or increased in scope

  8. Californium production at the transuranium processing plant

    International Nuclear Information System (INIS)

    King, L.J.

    1976-01-01

    The Transuranium Processing Plant (TRU) at ORNL, which is the production, storage, and distribution center for the ERDA heavy element research program, is described. About 0.5 percent of 252 Cf is currently being produced. TRU is a hot-cell, chemical processing facility of advanced design. New concepts have been incorporated into the facility for absolute containment, remote operation, remote equipment installation, and remote maintenance. The facilities include a battery of nine heavily shielded process cells served by master-slave manipulators and eight laboratories, four on each of two floors. Processing includes chemical dissolution of the targets followed by a series of solvent extraction, ion exchange, and precipitation steps to separate and purify the transuranium elements. The transcurium elements Bk, Cf, Es, and Fm are distributed to users. Remote techniques are used to fabricate the Am and Cm into target rods for reirradiation in the HFIR. Californium-252 that is in excess of the needs of the heavy element research program and the Cf sales program is stored at TRU and processed repeatedly to recover the daughter product 248 Cm, which is a highly desirable research material

  9. Data processing software for purex plant process control laboratory

    International Nuclear Information System (INIS)

    Kansara, V.P.; Achuthan, P.V.; Sridhar, S.; Ramanujam, A.; Dhumwad, R.K.

    1990-01-01

    A software has been developed at the Fuel Reprocessing Division, Trombay to meet the data processing needs of the Control Laboratory of a reprocessing plant. During the normal plant operations contents of over one hundred process tanks have to be sampled and analysed for regular monitoring. In order to speed up the computation and the reporting of results as well as to obtain the process performance data over a period of time a software has been developed. The package has been sucessfully demonstrated and implemented at the Plutonium Plant, Trombay. This has been in continuous use since May 1987 with highly satisfactory performance. The software is a totally menu-driven package which can be used by the laboratory analysts with a few hours of training. The features include data validation involving source tank identification, the nature of the sample, the range of expected results, any duplication in sample numbering etc. Audio indication of deviations from the expected input or output values are given with an option to override in case of abnormal samples. The progress of analysis can be obtained for a given sample at any given time. Incorporated in the software is the help menu for quick reference of analytical protocol to be followed for a given tank/method. The computations for the determinations are carried out after obtaining input values on a screen-form. Th e results can be displayed on the monitor or obtained in the form of a hard copy i n any desired format. (author). 17 figs., 2 refs

  10. Physicochemical studies as thorium soaps in solid state

    International Nuclear Information System (INIS)

    Mehrotra, K.N.; Gahlaut, A.S.; Sharma, M.

    1987-01-01

    The thermal decomposition of thorium soaps is kinetically of zero order and the energy of activation for the decomposition process lies in the range of 6-11 kcal mol -1 . Infrared spectral data indicate that the fatty acids exist with dimeric structure through hydrogen bonding between the carboxyl groups of acid molecules whereas the metal soaps have an ionic character. The X-ray diffraction studies of these soaps revealed that thorium soaps have double layer structure with molecular axes slightly inclined to the basal plane. (author). 10 refs., 5 figures

  11. Thorium in occupationally exposed men

    International Nuclear Information System (INIS)

    Stehney, A. F.

    1999-01-01

    Higher than environmental levels of 232 Th have been found in autopsy samples of lungs and other organs from four former employees of a thorium refinery. Working periods of the subjects ranged from 3 to 24 years, and times from end of work to death ranged from 6 to 31 years. Examination of the distribution of thorium among the organs revealed poor agreement with the distribution calculated from the dosimetric models in Publication 30 of the International Commission on Radioprotection (ICRP). Concentrations in the lungs relative to pulmonary lymph nodes, bone or liver were much higher than calculated from the model for class Y thorium and the exposure histories of the workers. Much better agreement was found with more recently proposed models in Publications 68 and 69 of the ICRP. Radiation doses estimated from the amounts of thorium in the autopsy samples were compatible with health studies that found no significant difference in mortality from that of the general population of men in the US

  12. Some thorium fuel cycle strategies

    International Nuclear Information System (INIS)

    Duret, M.F.; Hatton, H.

    1979-02-01

    The report deals with the problem of introducing an advanced nuclear fuel cycle based on thorium in Canada. It is pointed out that timing and introduction rate are important considerations, certain choices of these variables leading to undesirable business fluctuations in some of the industries involved in the production of nuclear energy. (author)

  13. Uranium, thorium and radium in soil and crops

    International Nuclear Information System (INIS)

    Evans, S.; Eriksson, Aa.

    1983-06-01

    The distribution of the naturally occuring radionuclides uranium, thorium and radium in soil, plant material and drainage water was evaluated. The plant/soil concentration factors showed that very small fractions of the nuclides were available for the plants. The water/soil concentration factors were calculated; the nuclide content in drainage water generally indicated very low leaching rates. The distribution of the radionuclides was utilized with the aim to obtain reliable concentration factors which in turn could be used to calculate the transfer of nuclides within the agricultural ecosystem. Dose calculations were performed using plant/soil concentration factors based on geometric mean values. (authors)

  14. Role of thorium in the industry advantage of atomic energy

    International Nuclear Information System (INIS)

    Souza Santos, M.D. de; Goldemberg, J.; Lopes, J.L.

    1985-01-01

    Based in the utilization of others fossil substances, such as plutonium and uranium 233, produzed through the thorium and natural uranium (238), it is discussed the relative merits of alternative processes: to produce U233 on Pu 239 to substitute the initial load of U235. (M.C.K.) [pt

  15. The chemistry of tributyl phosphate at elevated temperatures in the Plutonium Finishing Plant Process Vessels

    International Nuclear Information System (INIS)

    Barney, G.S.; Cooper, T.D.

    1994-01-01

    Potentially violent chemical reactions of the tributyl phosphate solvent used by the Plutonium Finishing Plant at the Hanford Site were investigated. There is a small probability that a significant quantity of this solvent could be accidental transferred to heated process vessels and react there with nitric acid or plutonium nitrate also present in the solvent extraction process. The results of laboratory studies of the reactions show that exothermic oxidation of tributyl phosphate by either nitric acid or actinide nitrates is slow at temperatures expected in the heated vessels. Less than four percent of the tributyl phosphate will be oxidized in these vented vessels at temperatures between 125 degrees C and 250 degrees C because the oxidant will be lost from the vessels by vaporization or decomposition before the tributyl phosphate can be extensively oxidized. The net amounts of heat generated by oxidation with concentrated nitric acid and with thorium nitrate (a stand-in for plutonium nitrate) were determined to be about -150 and -220 joules per gram of tributyl phosphate initially present, respectively. This is not enough heat to cause violent reactions in the vessels. Pyrolysis of the tributyl phosphate occurred in these mixtures at temperatures of 110 degrees C to 270 degrees C and produced mainly 1-butene gas, water, and pyrophosphoric acid. Butene gas generation is slow at expected process vessel temperatures, but the rate is faster at higher temperatures. At 252 degrees C the rate of butene gas generated was 0.33 g butene/min/g of tributyl phosphate present. The measured heat absorbed by the pyrolysis reaction was 228 J/g of tributyl phosphate initially present (or 14.5 kcal/mole of tributyl phosphate). Release of flammable butene gas into process areas where it could ignite appears to be the most serious safety consideration for the Plutonium Finishing Plant

  16. The chemistry of tributyl phosphate at elevated temperatures in the Plutonium Finishing Plant Process Vessels

    Energy Technology Data Exchange (ETDEWEB)

    Barney, G.S.; Cooper, T.D.

    1994-06-01

    Potentially violent chemical reactions of the tributyl phosphate solvent used by the Plutonium Finishing Plant at the Hanford Site were investigated. There is a small probability that a significant quantity of this solvent could be accidental transferred to heated process vessels and react there with nitric acid or plutonium nitrate also present in the solvent extraction process. The results of laboratory studies of the reactions show that exothermic oxidation of tributyl phosphate by either nitric acid or actinide nitrates is slow at temperatures expected in the heated vessels. Less than four percent of the tributyl phosphate will be oxidized in these vented vessels at temperatures between 125{degrees}C and 250{degrees}C because the oxidant will be lost from the vessels by vaporization or decomposition before the tributyl phosphate can be extensively oxidized. The net amounts of heat generated by oxidation with concentrated nitric acid and with thorium nitrate (a stand-in for plutonium nitrate) were determined to be about -150 and -220 joules per gram of tributyl phosphate initially present, respectively. This is not enough heat to cause violent reactions in the vessels. Pyrolysis of the tributyl phosphate occurred in these mixtures at temperatures of 110{degrees}C to 270{degrees}C and produced mainly 1-butene gas, water, and pyrophosphoric acid. Butene gas generation is slow at expected process vessel temperatures, but the rate is faster at higher temperatures. At 252{degrees}C the rate of butene gas generated was 0.33 g butene/min/g of tributyl phosphate present. The measured heat absorbed by the pyrolysis reaction was 228 J/g of tributyl phosphate initially present (or 14.5 kcal/mole of tributyl phosphate). Release of flammable butene gas into process areas where it could ignite appears to be the most serious safety consideration for the Plutonium Finishing Plant.

  17. Enhancing Elementary Pre-service Teachers' Plant Processes Conceptions

    Science.gov (United States)

    Thompson, Stephen L.; Lotter, Christine; Fann, Xumei; Taylor, Laurie

    2016-06-01

    Researchers examined how an inquiry-based instructional treatment emphasizing interrelated plant processes influenced 210 elementary pre-service teachers' (PTs) conceptions of three plant processes, photosynthesis, cellular respiration, and transpiration, and the interrelated nature of these processes. The instructional treatment required PTs to predict the fate of a healthy plant in a sealed terrarium (Plant-in-a-Jar), justify their predictions, observe the plant over a 5-week period, and complete guided inquiry activities centered on one of the targeted plant processes each week. Data sources included PTs' pre- and post-predictions with accompanying justifications, course artifacts such as weekly terrarium observations and science journal entries, and group models of the interrelated plant processes occurring within the sealed terraria. A subset of 33 volunteer PTs also completed interviews the week the Plant-in-a-Jar scenario was introduced and approximately 4 months after the instructional intervention ended. Pre- and post-predictions from all PTs as well as interview responses from the subgroup of PTs, were coded into categories based on key plant processes emphasized in the Next Generation Science Standards. Study findings revealed that PTs developed more accurate conceptions of plant processes and their interrelated nature as a result of the instructional intervention. Primary patterns of change in PTs' plant process conceptions included development of more accurate conceptions of how water is used by plants, more accurate conceptions of photosynthesis features, and more accurate conceptions of photosynthesis and cellular respiration as transformative processes.

  18. Evaluation of the concentrations of rare earth elements, uranium and thorium in the soil-plant system by Neutron Activation, k{sub 0} method

    Energy Technology Data Exchange (ETDEWEB)

    Moura, Rodrigo Reis de, E-mail: rodrigoreismoura@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Programa de Pós-Graduação em Ciências e Técnicas Nucleares; Menezes, Maria Ângela de Barros Correia, E-mail: menezes@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (SERTA/CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Serviço de Técnicas Analíticas; Marques, Douglas José, E-mail: douglasjmarques81@yahoo.com.br [Universidade José do Rosário Vellano (Unifenas), Alfenas, MG (Brazil). Setor de Olericultura e Experimentação em Agricultura Orgânica

    2017-07-01

    The nuclear technique Neutron Activation Analysis (NAA) has improved results in a wide range of research fields, since it is a sensitive technique to determine very low concentrations at the trace level in several matrices.The k0 standardized is a NAA method that has been outstanding in the last decades because there is not the inconvenience of using standards for the elements of interest in the analysis. This increases the accuracy of the method and decreases the uncertainties in the obtained results. In this assessment, the NAA was applied to determine the rare earth elements (REEs), U and Th concentrations in plant and soil samples from a mining area. The data obtained by k0-method were used to calculate the amount of the concentrations of these elements present in the sample soil that were uptaken and fractionated in the studied plants by parameters commonly used, the Transfer Factor (TF) and Bio-concentration Coefficient (BC). The results showed that TF was slightly enriched to REEs (mainly La and Nd) and U and depleted to Th. The results presented to BC confirmed that among plant organs the root accumulated higher REEs concentration levels (root > stem > leaf) and on leaves were not detected Sm (Baccharis crispa), Eu (Baccharis crispa and Tibouchina granulosa) and Yb (Pteridium arachnoideum). Among species studied, Pteridium arachnoideum (fern) was the one that most uptaken and accumulated REEs, U and Th. (author)

  19. Evaluation of the concentrations of rare earth elements, uranium and thorium in the soil-plant system by Neutron Activation, k0 method

    International Nuclear Information System (INIS)

    Moura, Rodrigo Reis de; Menezes, Maria Ângela de Barros Correia; Marques, Douglas José

    2017-01-01

    The nuclear technique Neutron Activation Analysis (NAA) has improved results in a wide range of research fields, since it is a sensitive technique to determine very low concentrations at the trace level in several matrices.The k0 standardized is a NAA method that has been outstanding in the last decades because there is not the inconvenience of using standards for the elements of interest in the analysis. This increases the accuracy of the method and decreases the uncertainties in the obtained results. In this assessment, the NAA was applied to determine the rare earth elements (REEs), U and Th concentrations in plant and soil samples from a mining area. The data obtained by k0-method were used to calculate the amount of the concentrations of these elements present in the sample soil that were uptaken and fractionated in the studied plants by parameters commonly used, the Transfer Factor (TF) and Bio-concentration Coefficient (BC). The results showed that TF was slightly enriched to REEs (mainly La and Nd) and U and depleted to Th. The results presented to BC confirmed that among plant organs the root accumulated higher REEs concentration levels (root > stem > leaf) and on leaves were not detected Sm (Baccharis crispa), Eu (Baccharis crispa and Tibouchina granulosa) and Yb (Pteridium arachnoideum). Among species studied, Pteridium arachnoideum (fern) was the one that most uptaken and accumulated REEs, U and Th. (author)

  20. Mechanism of thorium biosorption by the cells of the soil fungal isolate Geotrichum sp. dwc-1

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Congcong; Feng, Su [Sichuan Univ., Chengdu (China). Key Laboratory of Biological Resource and Ecological Environment; Li, Xiaolong [Sichuan Univ., Chengdu (China). Key Laboratory of Radiation Physics and Technology; and others

    2014-04-01

    In order to understand the impact of microorganisms on the fate of thorium in soils, we investigated the thorium biosorption behavior and the corresponding mechanisms by the cells of Geotrichum sp. dwc-1, one of the dominant species of fungal group isolated from 3.5 m depth soil layer in Southwest China. It was observed that fast thorium adsorption onto cells of G. sp. dwc-1 could take place, with a high distribution coefficient K{sub d} (0.93 mL/mg) obtained, when Geotrichum sp. dwc-1and thorium concentrations were 5 g/L and 10 mg/L, respectively. The thorium biosorption behavior was dependent on the pH value, and the lower pH could disrupt cell membrane of G. sp. dwc-1. At pH 1, thorium was accumulated in the cytoplasmic region of the cells. When pH was higher than 1, thorium was adsorbed on the cell surface of G. sp. dwc-1, like in periplasmic region or in the outer membrane. FTIR study combined with biosorption experiments further indicated that the thorium distribution and binding behavior on cell surface were associated with amino, hydroxyl groups and phosphate or sulphur functional groups, and might also be governed by electrostatic interaction. Moreover, PIXE and EPBS showed that ion-exchange mechanism contributed to the thorium biosorption process, in which the tetravalent thorium ions replaced smaller counter-ions (K{sup +}, Ca{sup 2+} and Fe{sup 3+}) occuring on the cell surface. (orig.)

  1. Thorium: Issues and prospects in Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    AL-Areqi, Wadeeah M.; Majid, Amran Ab.; Sarmani, Sukiman; Bahri, Che Nor Aniza Che Zainul [Nuclear Science Programme, School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Malaysia. walareqi@yahoo.com (Malaysia)

    2015-04-29

    In Malaysia, thorium exists in minerals and rare earth elements production residue. The average range of thorium content in Malaysian monazite and xenotime minerals was found about 70,000 and 15,000 ppm respectively. About 2,636 tonnes of Malaysian monazite was produced for a period of 5 years (2006-2010) and based on the above data, it can be estimated that Malaysian monazite contains about 184.5 tonnes of thorium. Although thorium can become a major radiological problem to our environment, but with the significant deposit of thorium in Malaysian monazite, it has a prospect as a future alternative fuel in nuclear technology. This paper will discuss the thorium issues in Malaysia especially its long term radiological risks to public health and environment at storage and disposal stages, the prospect of exploring and producing high purity thorium from our rare earth elements minerals for future thorium based reactor. This paper also highlights the holistic approach in thorium recovery from Malaysian rare earth element production residue to reduce its radioactivity and extraction of thorium and rare earth elements from the minerals with minimum radiological impact to health and environment.

  2. Thorium: Issues and prospects in Malaysia

    International Nuclear Information System (INIS)

    AL-Areqi, Wadeeah M.; Majid, Amran Ab.; Sarmani, Sukiman; Bahri, Che Nor Aniza Che Zainul

    2015-01-01

    In Malaysia, thorium exists in minerals and rare earth elements production residue. The average range of thorium content in Malaysian monazite and xenotime minerals was found about 70,000 and 15,000 ppm respectively. About 2,636 tonnes of Malaysian monazite was produced for a period of 5 years (2006-2010) and based on the above data, it can be estimated that Malaysian monazite contains about 184.5 tonnes of thorium. Although thorium can become a major radiological problem to our environment, but with the significant deposit of thorium in Malaysian monazite, it has a prospect as a future alternative fuel in nuclear technology. This paper will discuss the thorium issues in Malaysia especially its long term radiological risks to public health and environment at storage and disposal stages, the prospect of exploring and producing high purity thorium from our rare earth elements minerals for future thorium based reactor. This paper also highlights the holistic approach in thorium recovery from Malaysian rare earth element production residue to reduce its radioactivity and extraction of thorium and rare earth elements from the minerals with minimum radiological impact to health and environment

  3. Thorium: Issues and prospects in Malaysia

    Science.gov (United States)

    AL-Areqi, Wadeeah M.; Majid, Amran Ab.; Sarmani, Sukiman; Bahri, Che Nor Aniza Che Zainul

    2015-04-01

    In Malaysia, thorium exists in minerals and rare earth elements production residue. The average range of thorium content in Malaysian monazite and xenotime minerals was found about 70,000 and 15,000 ppm respectively. About 2,636 tonnes of Malaysian monazite was produced for a period of 5 years (2006-2010) and based on the above data, it can be estimated that Malaysian monazite contains about 184.5 tonnes of thorium. Although thorium can become a major radiological problem to our environment, but with the significant deposit of thorium in Malaysian monazite, it has a prospect as a future alternative fuel in nuclear technology. This paper will discuss the thorium issues in Malaysia especially its long term radiological risks to public health and environment at storage and disposal stages, the prospect of exploring and producing high purity thorium from our rare earth elements minerals for future thorium based reactor. This paper also highlights the holistic approach in thorium recovery from Malaysian rare earth element production residue to reduce its radioactivity and extraction of thorium and rare earth elements from the minerals with minimum radiological impact to health and environment.

  4. Thorium research and development in Turkey

    International Nuclear Information System (INIS)

    Güngör, Görkem

    2015-01-01

    Turkey has a great potential regarding thorium resources. Thorium exploration activities have been done in the past mainly by state organizations for determining the thorium resources in Turkey. Thorium occurs as complex mineral together with barite, fluorite and rare earth elements (REE). The increase in global demand for REE creates the opportunity for REE production which will also produce thorium as a by-product. The development of nuclear energy program in Turkey provides the stimulus for research and development activities in nuclear technologies. The final declaration of the workshop emphasizes the importance of thorium reserves in Turkey and the necessity for thorium exploration and development activities in order to determine the feasibility of thorium mining and fuel cycle in Turkey. These activities should be conducted together with the development of technologies for separation of these complex minerals and purification of thorium, REE and other minerals to be utilized as commercial products. There are advanced academic research studies on thorium fuel cycle which should be supported by the industry in order to commercialize the results of these studies. Turkey should be integrated to international R and D activities on ADS which is expected to commercialize on medium term. The legislative framework should be developed in order to provide the industrial baseline for nuclear technologies independent from nuclear regulatory activities

  5. Nuclear fuel re-processing plant

    International Nuclear Information System (INIS)

    Sasaki, Yuko; Honda, Takashi; Shoji, Saburo; Kobayashi, Shiro; Furuya, Yasumasa

    1989-01-01

    In a nuclear fuel re-processing plant, high Si series stainless steels not always have sufficient corrosion resistance in a solution containing only nitric acid at medium or high concentration. Further, a method of blowing NOx gases may possibly promote the corrosion of equipment constituent materials remarkably. In view of the above, the corrosion promoting effect of nuclear fission products is suppressed without depositing corrosive metal ions as metals in the nitric acid solution. That is, a reducing atmosphere is formed by generating NOx by electrolytic reduction thereby preventing increase in the surface potential of stainless steels. Further, an anode is disposed in the nitric acid solution containing oxidative metal ions to establish an electrical conduction and separate them by way of partition membranes and a constant potential or constant current is applied while maintaining an ionic state so as not to deposit metals. Thus, equipments of re-processing facility can be protected from corrosion with no particular treatment for wastes as radioactive materials. (K.M.)

  6. Analysis of Uranium and Thorium in Waste Water from Rare Earth Research and Development by ICP Spectrometry

    International Nuclear Information System (INIS)

    Pichestapong, Pipat; Injareon, Uthaiwan

    2007-08-01

    Full text: Waste water from Rare Earth Research and Development Center (RRDC) was analyzed to determine uranium and thorium concentration using ICP spectrometry. RRDC processes monazite ore to separate uranium, thorium and rare earth elements from the ore. Water samples from the ditch surrounding the center and from the canal nearby were also analyzed. Matrix spike technique was applied in this analysis. It was found that the highest concentration of uranium and thorium in the waste water samples were 3028±11 and 439±7 ppb, respectively. The concentration of uranium and thorium in the waste water samples were higher than those in water samples from the ditch and canal

  7. Performance of Energy Multiplier Module (EM2) with long-burn thorium fuel cycle

    International Nuclear Information System (INIS)

    Choi, Hangbok; Schleicher, Robert; Gupta, Puja

    2015-01-01

    Energy Multiplier Module (EM 2 ) is a helium-cooled fast reactor being developed by General Atomics for the 21 st century grid. It is designed as a modular plant with a net electric output of 265 MWe with an evaporative heat sink and 240 MWe with an air-cooled heat sink. EM 2 core performance is examined for the baseline loading of low-enriched uranium (LEU) as fissile material with depleted uranium (DU) as fertile material and compared to the alternate LEU with thorium loading. The latter has two options: a heterogeneous loading of thorium fuel in the place of DU that produces a longer fuel cycle, and homogeneously mixed thorium-uranium fuel loading. Compared to the baseline LEU/DU core, the cycle length of both thorium options is reduced due to higher neutron absorptions by thorium. However, for both, heterogeneous and homogenous thorium loading options, the fuel cycle length is over 24 years without refueling or reshuffling of fuel assemblies. The physics properties of the EM 2 thorium core are close to those of the baseline core which constitute low excess reactivity, negative fuel temperature coefficient, and very small void reactivity. However, unlike the case of baseline EM 2 , the homogeneous thorium fuel loading provides additional advantage in reducing the power peaking of the core, which in turn reduces the cladding material neutron damage rate by 23%. It is interpreted that the relatively slow 233 U buildup as compared to 239 Pu for baseline core retards reactivity increase without the need for a complicated fuel loading pattern of the heterogeneous fuel loading, while maintaining the peak power density low. Therefore both the heterogeneous and homogeneous thorium loading options will be feasible in the EM 2

  8. Research and development projects, new processes binded at the stop of a fuel fabrication plant (Nukem-A)

    International Nuclear Information System (INIS)

    Wehner, E.; Sohnius, B.

    1992-01-01

    This research work is aimed at the assessment of new procedures in the framework of the decommissioning of the NUKEM-A facility, a plant used for over 30 years for the fabrication of Material Test Reactor (MTR) and Thorium High Temperature Reactor (THTR) fuel elements. Important issues in this work are the preparation of detailed uranium and thorium contamination distribution maps in walls and floors, the execution of various dismantling and decontamination operations under health physics control, the large-scale treatment of arising primary waste and the minimization of secondary waste

  9. New plant improves radwaste processing at the Tokai-2 BWR

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    New plant for radiowaste processing at the Tokaj-2 NPP, put in operation in September, 1986, is described. The plant includes five systems providing processing of drianage water, solid waste combustion, decrease of volume and solidification of concentrated wastes, waste storage and flushing water processing. Pressed tablets represent the final product of the waste processing. New plant enables to reduce sufficiently the volume of radioactive wastes

  10. Health and Environmental Protection Standards for Uranium and Thorium Mill Tailings (40 CFR Part 192)

    Science.gov (United States)

    This regulation sets standards for the protection of public health, safety, and the environment from radiological and non-radiological hazards from uranium and thorium ore processing and disposal of associated wastes.

  11. Virginia ADS consortium - thorium utilization

    International Nuclear Information System (INIS)

    Myneni, Ganapati

    2015-01-01

    A Virginia ADS consortium, consisting of Virginia Universities (UVa, VCU, VT), Industry (Casting Analysis Corporation, GEM*STAR, MuPlus Inc.), Jefferson Lab and not-for-profit ISOHIM, has been organizing International Accelerator-Driven Sub-Critical Systems (ADS) and Thorium Utilization (ThU) workshops. The third workshop of this series was hosted by VCU in Richmond, Virginia, USA Oct 2014 with CBMM and IAEA sponsorship and was endorsed by International Thorium Energy Committee (IThEC), Geneva and Virginia Nuclear Energy Consortium Authority. In this presentation a brief summary of the successful 3 rd International ADS and ThU workshop proceedings and review the worldwide ADS plans and/or programs is given. Additionally, a report on new start-ups on Molten Salt Reactor (MSR) systems is presented. Further, a discussion on potential simplistic fertile 232 Th to fissile 233 U conversion is made

  12. Technology of getting of microspheric thorium dioxide

    International Nuclear Information System (INIS)

    Balakhonov, V.G.; Matyukha, V.A.; Saltan, N.P.; Filippov, E.A.; Zhiganov, A.N.

    1999-01-01

    There has been proposed a technique for getting granulated thorium dioxide from its salts solutions according to the cryogenic technology by the method of a solid phase conversion. It includes the following operations: dispersion of the initial solution into liquid nitrogen and getting of cryogranules of the necessary size by putting oscillations of definite frequency on a die device and by charging formed drops in the constant electric field; solid phase conversion of thorium salts into its hydroxide by treating cryogranules with a cooled ammonia solution, drying and calcination of hydroxide granules having got granulated thorium dioxide. At the pilot facility there have been defined and developed optimum regimes for getting granulated thorium dioxide. The mechanism of thorium hydroxide cryogranules conversion into thorium dioxide was investigated by the thermal analysis methods. (author)

  13. Thorium fuel cycle - Potential benefits and challenges

    International Nuclear Information System (INIS)

    2005-05-01

    There has been significant interest among Member States in developing advanced and innovative technologies for safe, proliferation resistant and economically efficient nuclear fuel cycles, while minimizing waste and environmental impacts. This publication provides an insight into the reasons for renewed interest in the thorium fuel cycle, different implementation scenarios and options for the thorium cycle and an update of the information base on thorium fuels and fuel cycles. The present TECDOC focuses on the upcoming thorium based reactors, current information base, front and back end issues, including manufacturing and reprocessing of thorium fuels and waste management, proliferation-resistance and economic issues. The concluding chapter summarizes future prospects and recommendations pertaining to thorium fuels and fuel cycles

  14. Prototype plant for nuclear process heat (PNP)

    International Nuclear Information System (INIS)

    Duerrfeld, R.; Kraut-Giesen, G.

    1982-01-01

    1. Goals: Verification of owner's interests during experimental and engineering phase of nuclear coal gasification. 2. Method: 2.1 Witnessing and evaluating of experimental results from running test facilities. 2.2 Influencing experimental program. 2.3 Participation in important meetings of PNP-project. 3. Results: From present point of view the realization of nuclear coal gasification with a nuclear high temperature reactor (HTR) in accordance with the present technical status as well as meeting the existing safety regulations seems to be feasable. R+D-work will be needed for affirmation of design. The gasification of hard coal basing on the allothermal principal has proved to be possible. The examination of the gasifier on a pilot scale is not yet done. The design work for the pilot plant should be started immediately, particularly keeping in mind the decision for erection of PNP in 1990. The calculation of production costs in comparison to autothermal gasification processes is promising better economics, if uncertainties of investment calculation are deemed to be neglectable. (orig.) [de

  15. Chemistry of uranium, thorium, and radium isotopes in the Ganga-Brahmaputra river system: Weathering processes and fluxes to the Bay of Bengal

    Science.gov (United States)

    Sarin, M. M.; Krishnaswami, S.; somayajulu, B. L. K.; Moore, W. S.

    1990-05-01

    The most comprehensive data set on uranium, thorium, and radium isotopes in the Ganga-Brahmaputra, one of the major river systems of the world, is reported here. The dissolved 238U concentration in these river waters ranges between 0.44 and 8.32 μ/1, and it exhibits a positive correlation with major cations (Na + K + Mg + Ca). The 238U /∑Cations ratio in waters is very similar to that measured in the suspended sediments, indicating congruent weathering of uranium and major cations. The regional variations observed in the [ 234U /238U ] activity ratio are consistent with the lithology of the drainage basins. The lowland tributaries (Chambal, Betwa, Ken, and Son), draining through the igneous and metamorphic rocks of the Deccan Traps and the Vindhyan-Bundelkhand Plateau, have [ 234U /238U ] ratio in the range 1.16 to 1.84. This range is significantly higher than the near equilibrium ratio (~1.05) observed in the highland rivers which drain through sedimentary terrains. The dissolved 226Ra concentration ranges between 0.03 and 0.22 dpm/1. The striking feature of the radium isotopes data is the distinct difference in the 228Ra and 226Ra abundances between the highland and lowland rivers. The lowland waters are enriched in 228Ra while the highland waters contain more 226Ra. This difference mainly results from the differences in their weathering regimes. The discharge-weighted mean concentration of dissolved 238U in the Ganga (at Patna) and in the Brahmaputra (at Goalpara) are 1.81 and 0.63 μ/1, respectively. The Ganga-Brahmaputra river system constitutes the major source of dissolved uranium to the Bay of Bengal. These rivers transport annually about 1000 tons of uranium to their estuaries, about 10% of the estimated global supply of dissolved uranium to the oceans via rivers. The transport of uranium by these rivers far exceeds that of the Amazon, although their water discharge is only about 20% of that of the Amazon. The high intensity of weathering of uranium in

  16. Minerals yearbook, 1991: Thorium. Annual report

    International Nuclear Information System (INIS)

    Hedrick, J.B.

    1992-10-01

    Domestic mine production data for thorium-bearing monazite are developed by the U.S. Bureau of Mines from a voluntary survey of U.S. operations entitled, 'Rare Earths, Thorium, and Scandium.' The one mine to which a survey form was sent responded, representing 100% of domestic production. Mine production data for thorium are withheld to avoid disclosing company proprietary data. Statistics on domestic thorium consumption are developed by surveying various processors and end users, evaluating import-export data, and analyzing Government stockpile shipments

  17. Information interfaces for process plant diagnosis

    International Nuclear Information System (INIS)

    Lind, M.

    1984-02-01

    The paper describes a systematic approach to the design of information interfaces for operator support in diagnosing complex systems faults. The need of interpreting primary measured plant variables within the framework of different system representations organized into an abstraction hierarchy is identified from an analysis of the problem of diagnosing complex systems. A formalized approach to the modelling of production systems, called Multilevel Flow Modelling, is described. A MFM model specifies plant control requirements and the associated need for plant information and provide a consistent context for the interpretation of real time plant signals in diagnosis of malfunctions. The use of MFM models as a basis for functional design of the plant instrumentation system is outlined, and the use of knowledge Based (Expert) Systems for the design of man-machine interfaces is mentioned. Such systems would allow an active user participation in diagnosis and thus provide the basis for cooperative problem solving. 14 refs. (author)

  18. Enhancing Elementary Pre-Service Teachers' Plant Processes Conceptions

    Science.gov (United States)

    Thompson, Stephen L.; Lotter, Christine; Fann, Xumei; Taylor, Laurie

    2016-01-01

    Researchers examined how an inquiry-based instructional treatment emphasizing interrelated plant processes influenced 210 elementary pre-service teachers' (PTs) conceptions of three plant processes, photosynthesis, cellular respiration, and transpiration, and the interrelated nature of these processes. The instructional treatment required PTs to…

  19. Study on thorium removal from effluent by electrocoagulation

    International Nuclear Information System (INIS)

    Nath, Baidurjya; Swaroopa Lakshmi, Y.V.; Tiwari, S.K.; Setty, D.S.; Kalyanakrishnan, G.; Saibaba, N.

    2015-01-01

    Coagulation-flocculation, membrane separation and ion-exchange are traditional methods for treatment of radioactive wastewater generated primarily from the front end processes of the fuel cycle. Electrocoagulation presents a robust and novel alternative to conventional coagulation process. The present study involves the establishment of electrocoagulation as a treatment process for thorium bearing non-process effluents in batch mode. This involved an electrolytic reactor with iron electrodes. The non-process effluent was subjected to coagulation and floatation by Fe(II) ions dissolved from the anode with the resultant flocs floating on the surface after being captured by hydrogen gas bubbles generated at the cathode. The effect of various operational parameters like initial pH, residence time, current density and initial thorium concentration on the removal efficiency was investigated. Maximum decontamination factor obtained was of the order of 10 4 . (author)

  20. Decontamination of liquid radioactive waste by thorium phosphate

    International Nuclear Information System (INIS)

    Rousselle, J.; Grandjean, S.; Dacheux, N.; Genet, M.

    2004-01-01

    In the field of the complete reexamination of the chemistry of thorium phosphate and of the improvement of the homogeneity of Thorium Phosphate Diphosphate (TPD, Th 4 (PO 4 ) 4 P 2 O 7 ) prepared at high temperature, several crystallized compounds were prepared as initial powdered precursors. Due to the very low solubility products associated to these phases, their use in the field of the efficient decontamination of high-level radioactive liquid waste containing actinides (An) was carefully considered. Two main processes (called 'oxalate' and 'hydrothermal' chemical routes) were developed through a new concept combining the decontamination of liquid waste and the immobilization of the actinides in a ceramic matrix (TPD). In phosphoric media ('hydrothermal route'), the key-precursor was the Thorium Phosphate Hydrogen Phosphate hydrate (Th 2 (PO 4 ) 2 (HPO 4 ). H 2 O, TPHP, solubility product log(K S,0 0 ) ∼ - 67). The replacement of thorium by other tetravalent actinides (U, Np, Pu) in the structure, leading to the preparation of Th 2-x/2 An x/2 (PO 4 ) 2 (HPO 4 ). H 2 O solid solutions, was examined. A second method was also considered in parallel to illustrate this concept using the more well-known precipitation of oxalate as the initial decontamination step. For this method, the final transformation to single phase TPD containing actinides was purchased by heating a mixture of phosphate ions with the oxalate precipitate at high temperature. (authors)

  1. Fabrication of thorium nitrate at the factory at the Bouchet

    International Nuclear Information System (INIS)

    Braun, C.; Lorrain, Ch.; Mahut, R.; Mariette, R.; Muller, J.; Prugnard, J.

    1958-01-01

    A urano-thorianite mineral from Madagascar is industrially treated at the factory of the Bouchet in order to obtain pure thorium in the form of the nitrate and a uranium concentrate in the form of uranate. The required factory was designed and constructed in 1955 and 1956 by the firm Potasse et Engrais Chimiques (P.E.C.) on behalf of the French Atomic Energy authority. The mineral which has previously undergone a gravimetric sorting and enrichment at the mine, is in the form of a heavy rock (the density can be as high as 10), having a cubic structure. It consists principally of a mixture of thorium oxide and uranium oxide and contains between 50 and 75 per cent thorium and between 5 and 20 per cent of uranium. On the same sample a high content in either thorium or uranium in general corresponds to a low content in the other of the two metals; this rule is not however always obeyed absolutely. Among other elements present we shall only mention the Pb, Fe, Ce, Ra and other radioactive elements, since their presence influences the treatment of the mineral. We shall first briefly describe the process, which has already been described in previous publications, we consider to be worthy of attention. (author) [fr

  2. Reference thorium fuel cycle

    International Nuclear Information System (INIS)

    Driggers, F.E.

    1978-08-01

    In the reference fuel cycle for the TFCT program, fissile U will be denatured by mixing with 238 U; the plants will be located in secure areas, with Pu being recycled within these secure areas; Th will be recycled with recovered U and Pu; the head end will handle a variety of core and blanket fuel assembly designs for LWRs and HWRs; the fuel may be a homogeneous mixture either of U and Th oxide pellets or sol-gel microspheres; the cladding will be Zircaloy; and MgO may be added to the fuel to improve Th dissolution. Th is being considered as the fertile component of fuel in order to increase proliferation resistance. Spent U recovered from Th-based fuels must be re-enriched before recycle to prevent very rapid buildup of 238 U. Stainless steel will be considered as a backup to Zircaloy cladding in case Zr is incompatible with commercial aqueous dissolution. Storage of recovered irradiated Th will be considered as a backup to its use in the recycle of recovered Pu and U. Estimates are made of the time for introducing the Th fuel cycle into the LWR power industry. Since U fuel exposures in LWRs are likely to increase from 30,000 to 50,000 MWD/MT, the Th reprocessing plant should also be designed for Th fuel with 50,000 MWD/MT exposure

  3. Control system for technological processes in tritium processing plants with process analysis

    International Nuclear Information System (INIS)

    Retevoi, Carmen Maria; Stefan, Iuliana; Balteanu, Ovidiu; Stefan, Liviu; Bucur, Ciprian

    2005-01-01

    Integration of a large variety of installations and equipment into a unitary system for controlling the technological process in tritium processing nuclear facilities appears to be a rather complex approach particularly when experimental or new technologies are developed. Ensuring a high degree of versatility allowing easy modifications in configurations and process parameters is a major requirement imposed on experimental installations. The large amount of data which must be processed, stored and easily accessed for subsequent analyses imposes development of a large information network based on a highly integrated system containing the acquisition, control and technological process analysis data as well as data base system. On such a basis integrated systems of computation and control able to conduct the technological process could be developed as well protection systems for cases of failures or break down. The integrated system responds to the control and security requirements in case of emergency and of the technological processes specific to the industry that processes radioactive or toxic substances with severe consequences in case of technological failure as in the case of tritium processing nuclear plant. In order to lower the risk technological failure of these processes an integrated software, data base and process analysis system are developed, which, based on identification algorithm of the important parameters for protection and security systems, will display the process evolution trend. The system was checked on a existing plant that includes a removal tritium unit, finally used in a nuclear power plant, by simulating the failure events as well as the process. The system will also include a complete data base monitoring all the parameters and a process analysis software for the main modules of the tritium processing plant, namely, isotope separation, catalytic purification and cryogenic distillation

  4. Complexation of thorium with pyridine monocarboxylates: A thermodynamic study by experiment and theory

    International Nuclear Information System (INIS)

    Rama Mohana Rao, D.; Rawat, Neetika; Manna, D.; Sawant, R.M.; Ghanty, T.K.; Tomar, B.S.

    2013-01-01

    Highlights: ► The thermodynamic parameters have been determined for the first time. ► The Th-picolinate complexation was exothermic in nature. ► The complexation of Th(IV) with the other two isomers was endothermic process. ► Isonicotinate forms stronger complexes than nicotinate with Th(IV). ► The theoretically calculated values are in line with the experimental results. -- Abstract: Complexation of thorium with pyridine monocarboxylates namely picolinic acid (pyridine-2-carboxylic acid), nicotinic acid (pyridine-3-carboxylic acid) and isonicotinic acid (pyridine-4-carboxylic acid) has been studied by potentiometry and calorimetry to determine the thermodynamic parameters (log K, ΔG, ΔH and ΔS) of complexation. All the studies were carried out at 1.0 M ionic strength adjusted by NaClO 4 and at a temperature of 298 K. The detailed analysis of potentiometric data by Hyperquad confirmed the formation of four complexes, ML i (i = 1–4) in case of picolinate but only one complex (ML) in case of nicotinate and isonicotinate. The stepwise formation constant for ML complex (log K ML ) of thorium-picolinate is higher than those of thorium-nicotinate and thorium-isonicotinate complexes. Further the changes in enthalpy during formation of thorium-picolinate complexes are negative whereas the same for the complexes of thorium with the other two isomers was positive. This difference in the complexation process is attributed to chelate formation in case of thorium-picolinate complexes in which the thorium ion is bound to the picolinate through both the nitrogen in the pyridyl ring and one of the carboxylate oxygen atoms. The complexation process of thorium-nicotinate and thorium-isonicotinate are found to be endothermic in nature and are entropy driven confirming the similar binding nature as in simple carboxylate complexes of thorium. The complexation energies, bond lengths and charges on each atom in the complexes of various possible geometries were calculated

  5. Electronic data processing codes for California wildland plants

    Science.gov (United States)

    Merton J. Reed; W. Robert Powell; Bur S. Bal

    1963-01-01

    Systematized codes for plant names are helpful to a wide variety of workers who must record the identity of plants in the field. We have developed such codes for a majority of the vascular plants encountered on California wildlands and have published the codes in pocket size, using photo-reductions of the output from data processing machines. A limited number of the...

  6. Biomonitoring of environmental pollution by thorium and uranium in selected regions of the Republic of Kazakhstan

    Energy Technology Data Exchange (ETDEWEB)

    Zoriy, P., E-mail: p.zoriy@fz-juelich.d [Institute of Safety and Radiation Protection in the Environment, Forschungszentrum Juelich, D-52428 Juelich (Germany); Ostapczuk, P.; Dederichs, H.; Hoebig, J.; Lennartz, R.; Zoriy, M. [Institute of Safety and Radiation Protection in the Environment, Forschungszentrum Juelich, D-52428 Juelich (Germany)

    2010-05-15

    Two former uranium mines and a uranium reprocessing factory in the city of Aktau, Kazakhstan, may represent a risk of contaminating the surrounding areas by uranium and its daughter elements. One of the possible fingerprinting tools for studying the environmental contamination is using plant samples, collected in the surroundings of this city in 2007 and 2008. The distribution pattern of environmental pollution by uranium and thorium was evaluated by determining the thorium and uranium concentrations in plant samples (Artemisia austriaca) from the city of Aktau and comparing these results with those obtained for the same species of plants from an unpolluted area (town of Kurchatov). The determination of the uranium and thorium concentrations in different parts of A. austriaca plants collected from the analyzed areas demonstrated that the main contamination of the flora in areas surrounding the city of Aktau was due to dust transported by the wind from the uranium mines. The results obtained demonstrate that all the areas surrounding Aktau have a higher pollution level due to thorium and uranium than the control area (Kurchatov). A few 'hot points' with high concentrations of uranium and thorium were found near the uranium reprocessing factory and the uranium mines.

  7. Radium accumulation in animal thyroid glands: a possible method for uranium and thorium prospecting

    International Nuclear Information System (INIS)

    Wogman, N.A.; Brodzinski, R.L.; Middlesworth, L.V.

    1976-01-01

    A method of prospecting for uranium and thorium is proposed based on uptake of their radioactive daughters, 226 Ra and 228 Ra, by plants, the collection of plant material by herbivores, the concentration of the radioactive species by specific animal tissues, and the subsequent gamma-ray analysis of the tissues

  8. Neutron irradiation effects on the mechanical properties of thorium and thorium--carbon alloy

    International Nuclear Information System (INIS)

    Wang, S.C.P.

    1978-04-01

    The effects of neutron exposure to 3.0 x 10 18 neutrons/cm 2 on the mechanical properties of thorium and thorium-carbon alloy are described. Tensile measurements were done at six different test temperatures from 4 0 K to 503 0 K and at two strain rates. Thorium and thorium-carbon alloy are shown to display typical radiation hardening like other face-centered cubic metals. The yield drop phenomenon of the thorium-carbon alloy is unchanged after irradiation. The variation of shear stress and effective shear stress with test temperature was fitted to Seeger's and Fleischer's equations for irradiated and unirradiated thorium and thorium-carbon alloy. Neutron irradiation apparently contributes an athermal component to the yield strength. However, some thermal component is detected in the low temperature range. Strain-rate parameter is increased and activation volume is decreased slightly for both kinds of metal after irradiation

  9. Transmutation Strategy Using Thorium-Reprocessed Fuel ADS for Future Reactors in Vietnam

    Directory of Open Access Journals (Sweden)

    Thanh Mai Vu

    2013-01-01

    Full Text Available Nuclear power is believed to be a key to the energy security for a developing country like Vietnam where the power demanding increases rapidly every year. Nevertheless, spent nuclear fuel from nuclear power plants is the source of radiotoxic and proliferation risk. A conceptual design of ADS utilizing thorium fuel as a based fuel and reprocessed fuel as a seed for nuclear waste transmutation and energy production is proposed as one of the clean, safe, and economical solutions for the problem. In the design, 96 seed assemblies and 84 blanket assemblies were inserted into the core to make a heterogeneous subcritical core configuration. Introducing thorium fuel into the core offers an effective way to transmute plutonium and minor actinide (MA and gain energy from this process. Transmutation rate as a function of burnup is estimated using MCNPX 2.7.0 code. Results show that by using the seed-blanket designed ADS, at 40 GWd/t burnup, 192 kg of plutonium and 156 kg of MA can be eliminated. Equivalently, 1  ADS can be able to transmute the transuranic (TRU waste from 2  LWRs. 14 units of ADS would be required to eliminate TRUs from the future reactors to be constructed in Vietnam.

  10. Cementation feasibility of a uranium-thorium based solution by physical and mechanical characterization

    International Nuclear Information System (INIS)

    Carpentiero, R.; Luce, A.; Troiani, F.

    2002-01-01

    By reprocessing Elk River nuclear fuel, at the ENEA ITREC Plant (South of Italy), about 3 m 3 of Uranium-Thorium based solution were produced. Previously considered an intermediate product to be further treated to recover U and Th, it is now being considered a waste, due to considerable content of fission products and to phasing out of the Italian nuclear industry. Together with other treatment options, a conditioning process in cement matrix is being evaluated, supported by some chemical, physical and mechanical tests on samples prepared with simulated waste. The main components selected to simulate the real solution were thorium nitrate (at two different concentrations), ferrous nitrate and nitric acid. This solution has been neutralized with sodium carbonate (at two different concentration) and cemented by means of a properly defined formulation. Pozzolanic blend cement, at different water to cement ratio, with and without a silica type additive, has been investigated. Cubic samples were subjected to compression tests and repeated freeze-thaw cycles followed by compression tests. Cylindrical samples were subjected to a leach test (according. to the tn ANSI/ANS-16.1 standard). The obtained results are above the minimum acceptance values established by the Italian authority. The evaluated properties are the first important elements to estimate the long term-instability of conditioned radioactive waste. Meanwhile a preliminary theoretical study has been done to evaluate the gas evolution from the matrix due to radiolysis effect. The reached conclusions encourage the development of further analysis to implement a cementation facility. (Author)

  11. Possible types of breeders with thorium cycle

    International Nuclear Information System (INIS)

    Ishiguro, Y.; Gouveia, A.S. de

    1981-01-01

    Neutronics calculations of simplified homogeneous reactor models show the possibility that metal-fueled LMFBRs and coated particle fueled gas cooled reactors achieve doubling times of around 10 years with the thorium cycle. Three concepts of gas-cooled thorium cycle breeders are discussed. (Author) [pt

  12. Possible types of breeders with thorium cycle

    International Nuclear Information System (INIS)

    Ishiguro, Y.; Gouveia, A.S. de.

    1981-02-01

    Neutronics calculations of simplified homogeneous reactor models show the possibility that metal-fueled LMFBRs and coated particle fueled gas cooled reactors achieve reactor doubling times of around 10 years with the thorium cycle. Three concepts of gas-cooled thorium cycle breeders are discused. (Author) [pt

  13. Thorium resources and energy utilization (14)

    International Nuclear Information System (INIS)

    Unesaki, Hironobu

    2014-01-01

    After the accident at the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Company, thorium reactor has been attracting attention from the viewpoint of safety. Regarding thorium as the resources for nuclear energy, this paper explains its estimated reserves in the whole world and each country, its features such as the situation of utilization, and the reason why it attracts attention now. The following three items are taken up here as the typical issues among the latest topics on thorium: (1) utilization of thorium as a tension easing measure against environmental effects involved in nuclear energy utilization, (2) thorium-based reactor as the next generation type reactor with improved safety, and (3) thorium utilization as the improvement policy of nuclear proliferation resistance. The outline, validity, and problems of these items are explained. Thorium reactor has been adopted as a research theme since the 1950s up to now mainly in the U.S. However, it is not enough in the aspect of technological development and also insufficient in the verification of reliability based on technological demonstration, compared with uranium-fueled light-water reactor. This paper explains these situations, and discusses the points for thorium utilization and future prospects. (A.O.)

  14. Thorium and health: state of the art

    International Nuclear Information System (INIS)

    Leiterer, A.; Berard, Ph.; Menetrier, F.

    2010-01-01

    This report reviews data available in the literature on the subject: 'thorium and health'. Thorium is a natural radioactive element of the actinide series. It is widely distributed in the earth's crust and 99% is found as isotope thorium-232. Its various uses are explained by its chemical, physical, and nuclear properties. As a potential nuclear fuel, thorium is still in demonstration in pilot scale reactors. But thorium has already multiple and sometimes unknown industrial uses. Some mass market products are concerned like light bulb. This raises the issue of wastes, and of exposures of workers and public. Environmental exposure via food and drink of the general population is low, where as workers can be exposed to significant doses, especially during ore extraction. Data on bio-monitoring of workers and biokinetic of thorium, in particular those provided by ICRP, are gathered here. Studies on health effects and toxicity of thorium are scarce and mostly old, except outcomes of its previous medical use. Studies on other forms of thorium should be undertaken to provide substantial data on its toxicity. Concerning treatment, Ca-DTPA is the recommended drug even if its efficacy is moderate. LiHOPO molecule shows interesting results in animals, and further research on chelating agents is needed. (authors)

  15. Interaction between thorium and potential clad materials

    International Nuclear Information System (INIS)

    Kale, G.B.; Gawde, P.S.; Sengupta, Pranesh

    2005-01-01

    Thorium based fuels are being used for nuclear reactors. The structural stability of fuel-clad assemblies in reactor systems depend upon the nature of interdiffusion reaction between fuel-cladding materials. Interdiffusion reaction thorium and various cladding materials is presented in this paper. (author)

  16. Reducing uranium and thorium level in Zircon: effect of heat treatment on rate of leaching

    International Nuclear Information System (INIS)

    Meor Yusoff Meor Sulaiman

    2002-01-01

    Considerable amount of uranium and thorium are found in Malaysian zircon and the level is much higher than the minimum value adopted by many importing countries. Selective leaching had been applied as an important technique to reduce these elements. An initial study was carried out using hydrochloric acid leaching system but the result was not favourable. The rate of uranium and thorium leached can be further improved by introducing a heat pretreatment process prior to leaching (Author)

  17. Homogeneous Thorium Fuel Cycles in Candu Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hyland, B.; Dyck, G.R.; Edwards, G.W.R.; Magill, M. [Chalk River Laboratories, Atomic Energy of Canada Limited (Canada)

    2009-06-15

    The CANDU{sup R} reactor has an unsurpassed degree of fuel-cycle flexibility, as a consequence of its fuel-channel design, excellent neutron economy, on-power refueling, and simple fuel bundle [1]. These features facilitate the introduction and full exploitation of thorium fuel cycles in Candu reactors in an evolutionary fashion. Because thorium itself does not contain a fissile isotope, neutrons must be provided by adding a fissile material, either within or outside of the thorium-based fuel. Those same Candu features that provide fuel-cycle flexibility also make possible many thorium fuel-cycle options. Various thorium fuel cycles can be categorized by the type and geometry of the added fissile material. The simplest of these fuel cycles are based on homogeneous thorium fuel designs, where the fissile material is mixed uniformly with the fertile thorium. These fuel cycles can be competitive in resource utilization with the best uranium-based fuel cycles, while building up a 'mine' of U-233 in the spent fuel, for possible recycle in thermal reactors. When U-233 is recycled from the spent fuel, thorium-based fuel cycles in Candu reactors can provide substantial improvements in the efficiency of energy production from existing fissile resources. The fissile component driving the initial fuel could be enriched uranium, plutonium, or uranium-233. Many different thorium fuel cycle options have been studied at AECL [2,3]. This paper presents the results of recent homogeneous thorium fuel cycle calculations using plutonium and enriched uranium as driver fuels, with and without U-233 recycle. High and low burnup cases have been investigated for both the once-through and U-233 recycle cases. CANDU{sup R} is a registered trademark of Atomic Energy of Canada Limited (AECL). 1. Boczar, P.G. 'Candu Fuel-Cycle Vision', Presented at IAEA Technical Committee Meeting on 'Fuel Cycle Options for LWRs and HWRs', 1998 April 28 - May 01, also Atomic Energy

  18. Thorium fuel performance assessment in HTRs

    Energy Technology Data Exchange (ETDEWEB)

    Allelein, H.-J. [Forschungszentrum Jülich, D-52425 Jülich (Germany); RWTH Aachen, D-52072 Aachen (Germany); Kania, M.J.; Nabielek, H. [Forschungszentrum Jülich, D-52425 Jülich (Germany); Verfondern, K., E-mail: k.verfondern@fz-juelich.de [Forschungszentrum Jülich, D-52425 Jülich (Germany)

    2014-05-01

    Thorium as a nuclear fuel is receiving renewed interest, because of its widespread availability and the good irradiation performance of Th and mixed (Th,U) oxide compounds as fuels in nuclear power systems. Early HTR development employed thorium together with high-enriched uranium. After 1980, most HTR fuel systems switched to low-enriched uranium. After completing fuel development for AVR and THTR with BISO coated particles, the German program expanded efforts on a new program utilizing thorium and high-enriched uranium TRISO coated particles for advanced HTR concepts for process heat applications (PNP) and direct-cycle electricity production (HHT). The combination of LTI inner and outer pyrocarbon layers surrounding a strong, stable SiC layer greatly improved manufacturing conditions and the subsequent contamination and defective particle fractions in production fuel elements. In addition, this combination provided improved mechanical strength and a higher degree of solid fission product retention, not known previously with HTI-BISO coatings. The improved performance of the HEU (Th,U)O{sub 2} TRISO fuel system was successfully demonstrated in three primary areas of development: manufacturing, irradiation testing under normal operating conditions, and accident simulation testing. In terms of demonstrating performance for advanced HTR applications, the experimental failure statistic from manufacture and irradiation testing are significantly below the coated particle requirements specified for PNP and HHT designs at the time. Covering a range to 1300 °C in normal operations and 1600 °C in accidents, with burnups up to 13% FIMA and fast fluences to 8 × 10{sup 25} m{sup −2} (E > 16 fJ), the results exceed the design limits on manufacturing and operational requirements for the German HTR Modul concept, which were: <6.5 × 10{sup −5} for manufacturing; <2 × 10{sup −4} for normal operating conditions; and <5 × 10{sup −4} for accident conditions. These

  19. Geochemical prospecting for thorium and uranium deposits

    International Nuclear Information System (INIS)

    Boyle, R.W.

    1982-01-01

    The basic purpose of this book is to present an analysis of the various geochemical methods applicable in the search for all types of thorium and uranium deposits. The general chemistry and geochemistry of thorium and uranium are briefly described in the opening chapter, and this is followed by a chapter on the deposits of the two elements with emphasis on their indicator (pathfinder) elements and on the primary and secondary dispersion characteristics of thorium and uranium in the vicinity of their deposits. The next seven chapters form the main part of the book and describe geochemical prospecting for thorium and uranium, stressing selection of areas in which to prospect, radiometric surveys, analytical geochemical surveys based on rocks (lithochemical surveys), unconsolidated materials (pedochemical surveys), natural waters and sediments (hydrochemical surveys), biological materials (biogeochemical surveys), gases (atmochemical surveys), and miscellaneous methods. A final brief chapter reviews radiometric and analytical methods for the detection and estimation of thorium and uranium. (Auth.)

  20. Utilization of thorium in thermal reactors

    International Nuclear Information System (INIS)

    Srinivasan, K.R.; Nakra, A.N.

    1978-01-01

    Large deposits of thorium are found in India. 233 U produced by neutron capture in 232 Th is a more valuable fuel for thermal reactors than the plutonium that results from capture in 238 U. These two facts are the main reasons for the interest in utilizing thorium in power reactors. But natural thorium does not contain any fissile material and its capture cross section is nearly two and a half times that of 238 U. These have made the fuelling cost high. However, in certain conditions and certain types of reactors the costs are comparable with those using uranium fuel. The relative cost effectiveness of different fuels is discussed. Apart from long term interest, the short term interest of using thorium fuel in RAPP type reactors is also briefly described. Finally the reactor physics experiments using thorium fuel and their comparison with calculations are presented. (author)

  1. Proceedings: Distributed digital systems, plant process computers, and networks

    International Nuclear Information System (INIS)

    1995-03-01

    These are the proceedings of a workshop on Distributed Digital Systems, Plant Process Computers, and Networks held in Charlotte, North Carolina on August 16--18, 1994. The purpose of the workshop was to provide a forum for technology transfer, technical information exchange, and education. The workshop was attended by more than 100 representatives of electric utilities, equipment manufacturers, engineering service organizations, and government agencies. The workshop consisted of three days of presentations, exhibitions, a panel discussion and attendee interactions. Original plant process computers at the nuclear power plants are becoming obsolete resulting in increasing difficulties in their effectiveness to support plant operations and maintenance. Some utilities have already replaced their plant process computers by more powerful modern computers while many other utilities intend to replace their aging plant process computers in the future. Information on recent and planned implementations are presented. Choosing an appropriate communications and computing network architecture facilitates integrating new systems and provides functional modularity for both hardware and software. Control room improvements such as CRT-based distributed monitoring and control, as well as digital decision and diagnostic aids, can improve plant operations. Commercially available digital products connected to the plant communications system are now readily available to provide distributed processing where needed. Plant operations, maintenance activities, and engineering analyses can be supported in a cost-effective manner. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database

  2. Plant Cytokinesis: Terminology for Structures and Processes

    Czech Academy of Sciences Publication Activity Database

    Smertenko, A.; Assaad, F.F.; Baluška, F.; Bezanilla, M.; Buschmann, B.; Drakakaki, G.; Hauser, M.T.; Janson, M.; Mineyuki, Y.; Moore, I.; Mueller, S.; Murata, T.; Otegui, M.S.; Panteris, E.; Rasmussen, C.; Schmit, A. C.; Šamaj, J.; Samuels, L.; Staehelin, L. A.; Van Damme, D.; Wasteneys, G.; Žárský, Viktor

    2017-01-01

    Roč. 27, č. 12 (2017), s. 885-894 ISSN 0962-8924 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : cell plate formation * microtubule-associated protein * dividing root- cell s * preprophase-band formation * cortical division zone * trans-golgi network * physcomitrella-patens * arabidopsis-thaliana * somatic cytokinesis * tobacco by-2 Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Plant sciences, botany Impact factor: 15.333, year: 2016

  3. Thorium in heavy water reactors

    International Nuclear Information System (INIS)

    Andersson, G.

    1984-12-01

    Advanced heavy water reactors can provide energy on a global scale beyond the foreseeable future. Their economic and safety features are promising: 1. The theoretical feasibility of the Self Sufficient Equilibrium Thorium (SSET) concept is confirmed by new calculations. Calculations show that the adjuster rod geometry used in natural uranium CANDU reactors is adequate also for SSET if the absorption in the rods is graded. 2. New fuel bundle designs can permit substantially higher power output from a CANDU reactor. The capital cost for fuel, heavy water and mechanical equipment can thereby be greatly reduced. Progress is possible with the traditional fuel material oxide, but the use of thorium metal gives much larger effects. 3. A promising long range possibility is to use pressure tanks instead of pressure tubes. Heat removal from the core is facilitated. Negative temperature and void coefficients provide inherent safety features. Refuelling under power is no longer needed if control by moderator displacement is used. Reduced quality demand on the fuel permits lower fuel costs. The neutron economy is improved by the absence of pressure and clandria tubes and also by the use of radial and axial blankets. A modular seed blanket design can reduce the Pa losses. The experience from construction of tank designs is good e.g. AAgesta, Attucha. It is now also possible to utilize technology from LWR reactors and the implementation of advanced heavy water reactors would thus be easier than HTR or LMFBR systems. (Author)

  4. Origin of blue emission in thorium oxide nanorods

    International Nuclear Information System (INIS)

    Gupta, Santosh K.; Natarajan, V.; Ghosh, P.S.; Arya, A.

    2014-01-01

    Thorium oxide, ThO 2 , has long been an important material in the nuclear industry and has more recently found utility in the design of a variety of new materials, including catalysts, electrodes, fuel cell, electrolytes and sensors. Thorium dioxide is an interesting host matrix for a variety of reasons like its low phonon energy (∼450 cm -1 ), which reduces the non-radiative losses. Among all the chemical processes, the micro emulsion processing (reverse micelles synthesis) has been demonstrated as a very versatile and reproducible method. Luminescence of pure metal oxides is usually assigned to crystal lattice defects formed by oxygen vacancies but the obvious experimental evidences for this assumption are absent. Optical properties of stoichiometric and oxygen-deficient thoria have never been investigated previously

  5. Process Information System - Nuclear Power Plant Krsko

    International Nuclear Information System (INIS)

    Mandic, D.; Barbic, B.; Linke, B.; Colak, I.

    1998-01-01

    Original NEK design was using several Process Computer Systems (PCS) for both process control and process supervision. PCS were built by different manufacturers around different hardware and software platforms. Operational experience and new regulatory requirements imposed new technical and functional requirements on the PCS. Requirements such as: - Acquisition of new signals from the technological processes and environment - Implementation of new application programs - Significant improvement of MMI (Man Machine Interface) - Process data transfer to other than Main Control Room (MCR) locations - Process data archiving and capability to retrieve same data for future analysis were impossible to be implemented within old systems. In order to satisfy new requirements, NEK has decided to build new Process Information System (PIS). During the design and construction of the PIS Project Phase I, in addition to the main foreign contractor, there was significant participation of local architect engineering and construction companies. This paper presents experience of NEK and local partners. (author)

  6. Spectrographic determination of some rare earths in thorium compounds

    International Nuclear Information System (INIS)

    Brito, J. de.

    1977-01-01

    A method for spectrographic determination of Gd, Sm, Dy, Eu, Y, Yb, Tm and Lu in thorium compounds has been developed. Sensibilities of 0.01 μg rare earths/g Th02 were achieved. The rare earth elements were chromatographycally separated in a nitric acid-ether-cellulose system. The solvent mixture was prepared by dissolving 11% of concentrated nitric acid in ether. The method is based upon the sorption of the rare earths on activated cellulose, the elements being eluted together with 0.01 M HNO 3 . The retention of the 152 , 154 Eu used as tracer was 99,4%. The other elements showed recoveries varying from 95 to 99%. A direct carrier destillation procedure for the spectrochemical determination of the mentioned elements was used. Several concentrations of silver chloride were used to study the volatility behavior of the rare earths. 2%AgCl was added to the matrix as definite carrier, being lantanum selected as internal standard. The average coefficient of variation for this method was +- -+ 7%. The method has been appleid to the analysis of rare earths in thorium coumpounds prepared by Thorium Purification Pilot Plant at Atomic Energy Institute, Sao Paulo [pt

  7. Review of experience gained in fabricating nuclear grade uranium and thorium compounds and their analytical quality control at the Instituto de Energia Atomica, Sao Paulo, Brazil

    International Nuclear Information System (INIS)

    Abrao, A.; Franca, J.M. Jr.; Ikuta, A.; Pueschel, C.R.; Federgruen, L.; Lordello, A.R.; Tomida, E.K.; Moraes, S.; Brito, J. de; Gomes, R.P.; Araujo, J.A.; Floh, B.; Matsuda, H.T.

    1977-01-01

    This paper summarizes the main activities dealing with the fabrication of nuclear grade uranium and thorium compounds at the Instituto de Energia Atomica, Sao Paulo. Identification of problems and their resolutions, the experience gained in plant operation, the performance characteristics of an ion-exchange facility and a solvent extraction unit (a demonstration plant based on pulsed columns for purification of uranium and production of ammonium diuranate) are described. A moving-bed facility for UF 4 preparation and its operation is discussed. A pilot plant for uranium and thorium oxide microsphere preparation based on internal gelation for HTGR fuel type is also described. A solvent extraction pilot plant for thorium purification based on a compound extraction-scrubbing column and a mixer-settler battery and the involved technology for thorium purification are commented. The main products, namely ammonium diuranate, uranyl amonium tricarbonate, uranium trioxide, uranium tetrafluoride, thorium nitrate and thorium oxalate and their quality are commented. The development of necessary analytical procedures for the quality control of the mentioned nuclear grade products is summarized. A great majority of such procedures was particularly suitable for analyzing traces impurities. Designed for installation are the units for denitration of uranyl nitrate solutions and pilot plants for elemental fluorine and UF 6 . The installation of a laboratory-scale plant designed for reprocessing irradiated uranium and an experimental unit for the recovery of protactinium from irradiated thorium is in progress

  8. Future of robots in nuclear plants and processes

    International Nuclear Information System (INIS)

    Fisher, J.J.; Byrd, J.S.

    1985-01-01

    The role of robotics at the Savannah River Plant and Laboratory is reviewed. The site's remote process areas are described briefly, and existing remote handling equipment and robots are discussed. Three technology areas under development and relating to process automation are reviewed. These are: inspection systems to detect and evaluate process problems or to determine equipment integrity, process monitoring systems to analyze plant operations and to supply information in the event of an unusual occurrence, and remote manipulator systems and controls to handle instruments and tools. A technique is presented for employing future intelligent robots through process networks. These networks will represent the integration of robotic technology with dedicated process knowledge bases

  9. Nuclear reactor plant for production process heat

    International Nuclear Information System (INIS)

    Weber, M.

    1979-01-01

    The high temperature reactor is suitable as a heat source for carrying out endothermal chemical processes. A heat exchanger is required for separating the reactor coolant gases and the process medium. The heat of the reactor is transferred at a temperature lower than the process temperature to a secondary gas and is compressed to give the required temperature. The compression energy is obtained from the same reactor. (RW) [de

  10. Impact of treated effluents released from processing of radioactive mineral on the aquatic environment of Periyar river

    International Nuclear Information System (INIS)

    Radhakrishnan, Sujata; Haridasan, P.P.; Radhakrishna Pillai, K.; Pillai, P.M.B.; Khan, A.H.

    2005-01-01

    The chemical processing of monazite/ thorium concentrate for the separation of thorium, uranium and rare earths results in the generation of effluents, both acidic and alkaline. Indian Rare Earths Ltd (IREL), Udyogamandal was carrying out processing of monazite for nearly 50 years. Presently (since 2004) Indian Rare Earths Ltd, Udyogamandal is processing earlier stocked thorium hydroxide concentrate retrieved from Silos to produce Thorium Oxalate (along with a small percentage of Rare Earth elements), Nuclear Grade Ammonium Di-Uranate (NGADU), and small quantities of Nuclear Grade Thorium Oxide ('THRUST' Project). The treated effluents after monitoring are discharged to river Periyar. River Periyar is the recipient water body for treated effluents from IREL as well as a host of other chemical industries. Indian Rare Earths Ltd, Udyogamandal had been carrying out chemical processing of monazite for the past 50 years. Recently, from 2004, the plant has shifted from monazite processing to processing of thorium concentrate (THRUST Project). The present paper discusses the characteristics of the effluents generated as per this project, their treatment, monitoring methodology, discharge and impact on the aquatic environment of river Periyar. It has been noted that the impact on the aquatic environment by way of enhancing the natural background radioactivity in the river had been insignificant. (author)

  11. Organizational processes and nuclear power plant safety

    International Nuclear Information System (INIS)

    Landy, F.J.; Jacobs, R.R.; Mathieu, J.

    1991-01-01

    The paper describes the effects organizational factors have on the risk associated with the operation of nuclear power plants. The described research project addresses three methods for identifying the organizational factors that impact safety. The first method consists of an elaborate theory-based protocol dealing with decision making procedures, interdepartmental coordination of activities, and communications. The second, known as goals/means/measures protocol, deals with identifying safey related goals. The third method is known as behaviorally anchored rating scale development. The paper discusses the importance of the convergence of these three methods to identify organizational factors essential to reactor safety

  12. Process monitoring for reprocessing plant safeguards: a summary review

    International Nuclear Information System (INIS)

    Kerr, H.T.; Ehinger, M.H.; Wachter, J.W.; Hebble, T.L.

    1986-10-01

    Process monitoring is a term typically associated with a detailed look at plant operating data to determine plant status. Process monitoring has been generally associated with operational control of plant processes. Recently, process monitoring has been given new attention for a possible role in international safeguards. International Safeguards Project Office (ISPO) Task C.59 has the goal to identify specific roles for process monitoring in international safeguards. As the preliminary effort associated with this task, a review of previous efforts in process monitoring for safeguards was conducted. Previous efforts mentioned concepts and a few specific applications. None were comprehensive in addressing all aspects of a process monitoring application for safeguards. This report summarizes the basic elements that must be developed in a comprehensive process monitoring application for safeguards. It then summarizes the significant efforts that have been documented in the literature with respect to the basic elements that were addressed

  13. Nuclear plant needs for new process instrumentation

    International Nuclear Information System (INIS)

    Weiss, J.; Belew, M.

    1991-01-01

    Electric Power Research Institute (EPRI) is initiating projects to investigate new sensor designs for pressure and hydrogen measurements. The intent is to develop new sensors that are highly accurate with inherently low-maintenance requirements. Criteria have been developed, with utility review and input, for evaluating pressure sensor technology. The first phase will evaluate all pressure-sensing concepts, including new techniques such as fiber optics, digital silicon, reductance, acoustics, and others (exploratory research). Concepts that appear most attractive for meeting the utility criteria will be extended. The second phase would be conceptual development, laboratory testing, market surveys, manufacturing assessments, plant implementation assessments, and a cost/benefits assessment. Assuming positive results from phase 2, phase 3 would be prototype sensor development and host plant testing. Phase 4 (funded outside EPRI) would be qualification testing. Hydrogen sensor assessment studies are under way to determine the need for improved hydrogen sensor designs. If the results of the assessment indicate a need, a project to develop improved hydrogen sensors utilizing a similar multiphase approach will also be initiated

  14. Plants in constructed wetlands help to treat agricultural processing wastewater

    Directory of Open Access Journals (Sweden)

    Mark Grismer

    2008-05-01

    Full Text Available Over the past three decades, wineries in the western United States and sugarcane processing for ethanol in Central and South America have experienced problems related to the treatment and disposal of process wastewater. Both winery and sugarcane (molasses wastewaters are characterized by large organic loadings that change seasonally and are detrimental to aquatic life. We examined the role of plants for treating these wastewaters in constructed wetlands. In the greenhouse, subsurface-flow flumes with volcanic rock substrates and plants steadily removed approximately 80% of organic-loading oxygen demand from sugarcane process wastewater after about 3 weeks of plant growth; unplanted flumes removed about 30% less. In field studies at two operational wineries, we evaluated the performance of similar-sized, paired, subsurface constructed wetlands with and without plants; while both removed most of the oxygen demand, removal rates in the planted system were slightly greater and significantly different from those of the unplanted system under field conditions.

  15. Determination of natural thorium in urines; Dosage du thorium dans les urines

    Energy Technology Data Exchange (ETDEWEB)

    Jeanmaire, L; Jammet, H [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    A procedure for the quantitative analysis of thorium in urine is described. After precipitation with ammonium hydroxide, dissolution of the precipitate, extraction at pH 4-4.2 with cupferron in chloroformic solution and mineralization, a colorimetric determination of thorium with thorin is performed. It is thus possible to detect about 2 {gamma} of thorium in the sample. (author) [French] Cet article decrit une technique de dosage du thorium dans l'urine. Apres precipitation par l'ammoniaque, remise en solution, extraction a pH 4-4,2 par le cupferron en solution chloroformique et mineralisation, le thorium est dose par colorimetrie avec le thorin. Cette methode permet de deceler environ 2 {gamma} de thorium dans l'echantillon. (auteur)

  16. Chemistry of titanium, zirconium and thorium picramates

    International Nuclear Information System (INIS)

    Srivastava, R.S.; Agrawal, S.P.; Bhargava, H.N.

    1976-01-01

    Picramates of titanium, zirconium and thorium are prepared by treating the aqueous sulphate, chloride and nitrate solutions with sodium picramate. Micro-analysis, colorimetry and spectrophotometry are used to establish the compositions (metal : ligand ratio) of these picramates as 1 : 2 (for titanium and zirconium) and 1 : 4 (for thorium). IR studies indicate H 2 N → Me coordination (where Me denotes the metal). A number of explosive properties of these picramates point to the fact that the zirconium picramate is thermally more stable than the picramates of titanium and thorium. (orig.) [de

  17. The importance of thorium in the context of the generation in advanced reactors and the IPEN's experience

    International Nuclear Information System (INIS)

    Lainetti, Paulo E.O.; Mindrisz, Ana C.; Freitas, Antonio A.

    2011-01-01

    thorium compounds and IPEN accumulated since the 60's a wide experience in the purification of thorium, obtained primarily from the monazite processing. Studies were also conducted on obtaining nuclear fuel based on thorium, the reduction of ThF 4 to metallic thorium, neutronic studies and proposition of reactor concepts based on the element. It should also be recorded that there was at IPEN, during this period, the production in pilot scale of over one hundred and seventy metric tons of thorium nitrate with high purity. In this paper, we present briefly the experience accumulated at IPEN-CNEN/SP-Brazil and the different areas that comprise the Thorium Fuel Cycle, and the possibilities and advantages of thorium use in the IV Generation Advanced Reactors. (author)

  18. Performance Analysis Review of Thorium TRISO Coated Particles during Manufacture, Irradiation and Accident Condition Heating Tests

    International Nuclear Information System (INIS)

    2015-03-01

    Thorium, in combination with high enriched uranium, was used in all early high temperature reactors (HTRs). Initially, the fuel was contained in a kernel of coated particles. However, particle quality was low in the 1960s and early 1970s. Modern, high quality, tristructural isotropic (TRISO) fuel particles with thorium oxide and uranium dioxide (UO 2 ) had been manufactured since 1978 and were successfully demonstrated in irradiation and accident tests. In 1980, HTR fuels changed to low enriched uranium UO 2 TRISO fuels. The wide ranging development and demonstration programme was successful, and it established a worldwide standard that is still valid today. During the process, results of the thorium work with high quality TRISO fuel particles had not been fully evaluated or documented. This publication collects and presents the information and demonstrates the performance of thorium TRISO fuels.This publication is an outcome of the technical contract awarded under the IAEA Coordinated Research Project on Near Term and Promising Long Term Options for Deployment of Thorium Based Nuclear Energy, initiated in 2012. It is based on the compilation and analysis of available results on thorium TRISO coated particle performance in manufacturing and during irradiation and accident condition heating tests

  19. Coal Preparation and Processing Plants New Source Performance Standards (NSPS)

    Science.gov (United States)

    Learn about the NSPS regulation for coal preparation and processing plants by reading the rule summary, the rule history, the code of federal regulation text, the federal register, and additional docket documents

  20. Fabrication routes for Thorium and Uranium233 based AHWR fuel

    International Nuclear Information System (INIS)

    Danny, K.M.; Saraswat, Anupam; Chakraborty, S.; Somayajulu, P.S.; Kumar, Arun

    2011-01-01

    India's economic growth is on a fast growth track. The growth in population and economy is creating huge demand for energy which has to be met with environmentally benign technologies. Nuclear Energy is best suited to meet this demand without causing undue environmental impact. Considering the large thorium reserves in India, the future nuclear power program will be based on Thorium- Uranium 233 fuel cycle. The major characteristic of thorium as the fuel of future comes from its superior fuel utilization. 233 U produced in a reactor is always contaminated with 232 U. This 232 U undergoes a decay to produce 228 Th and it is followed by decay chain including 212 Bi and 208 Tl. Both 212 Bi and 208 Tl are hard gamma emitters ranging from 0.6 MeV-1.6 MeV and 2.6 MeV respectively, which necessitates its handling in hot cell. The average concentration of 232 U is expected to exceed 1000 ppm after a burn-up of 24,000 MWD/t. Work related to developing the fuel fabrication technology including automation and remotization needed for 233 U based fuels is in progress. Various process for fuel fabrication have been developed i.e. Coated Agglomerate Pelletisation (CAP), impregnation technique (Pellet/Gel), Sol Gel Micro-sphere Pelletisation (SGMP) apart from Powder to Pellet (POP) route. This paper describes each process with respect to its advantages, disadvantages and its amenability to automation and remotisation. (author)

  1. Alkaline autoclave leaching of refractory uranium-thorium minerals

    International Nuclear Information System (INIS)

    Milani, S. A.; Sam, S.

    2011-01-01

    This paper deals with the study of an innovative method for processing the Oman placer ores by alkaline leaching in ball mill autoclaves, where grinding and leaching of the refractory minerals take place simultaneously. This was followed by the selective separation of thorium and uranium from lanthanides by autoclave leaching of the hydroxide cake with ammonium carbonate-bicarbonate solutions. The introduced method is based on the fact that thorium and uranium form soluble carbonate complexes with ammonium carbonate, while lanthanides form sparingly soluble double carbonates. It was found that a complete alkaline leaching of Oman placer ores (98.0 P ercent ) was attained at 150 and 175 d egree C within 2.5 and 2h, respectively. Oman placer ores leaching was intensified and accelerated in a ball mill autoclaves as a result of the grinding action of steel balls, removal of the hydroxide layer covering ores grains and the continuous contact of fresh ore grains with alkaline solution. The study of selective carbonate processing of hydroxide cake with ammonium carbonate-bicarbonate solutions on autoclave under pressure revealed that the complete thorium recovery (97.5 P ercent ) with uranium recovery (90.8 P ercent ) and their separation from the lanthanides were attained at 70-80 d egree C during l-2h. The extraction of lanthanides in carbonate solution was low and did not exceed 4.6 P ercent .

  2. Screen-based process control in nuclear plants

    International Nuclear Information System (INIS)

    Hinz, W.; Arnoldt, C.; Hessler, C.

    1993-01-01

    Requirements, development and conceptual design of a screen-based control room for nuclear power plants are outlined. The control room consists of three or four equally equipped operator workstations comprising screens for process information and manual process control. A plant overview will assist the coordination among the operators. A safety classified backup system (safety control area) is provided to cover postulated failures of the control means. Some aspects of ergonomical validation and of future development trends are discussed. (orig.) [de

  3. Egg processing plant sanitation, SSOPs, and GMPs.

    Science.gov (United States)

    The basis of food safety programs in processing facilities is prerequisite programs such as sanitation and good manufacturing practices. Thoughtful, thorough, and complete sanitation programs are necessary to enhance the food safety of products and reduce the likelihood of foodborne illness. Egg p...

  4. Safeguards planning in a plant design process

    International Nuclear Information System (INIS)

    Heinrich, L.A.

    1977-01-01

    The safeguards efforts for the partitioning fuel cycle are considered. Included in the discussion are the organization of the safeguards study, the development of safeguards criteria, the expression of these criteria as requirements for facility design, and some preliminary details of the implementation of these requirements in facility and process layout

  5. Purex process operation and performance, 1970 Thoria Campaign

    International Nuclear Information System (INIS)

    Jackson, R.R.; Walser, R.L.

    1977-03-01

    The Hanford Purex Plant fulfilled a 1970 commitment to the Atomic Energy Commission to produce 360 kilograms of high purity 233 U as uranyl nitrate solution. Overall plant performance during both 1970 and 1966 confirmed the suitability of Purex for processing thorium on a campaign basis. The 1970 processing campaign, including flushing operations, is discussed with particular emphasis on problem areas. Background information on the process and equipment used is also presented. The organizations and their designations described are those existing in 1970

  6. Industrial applications for remote operation in a processing plant

    International Nuclear Information System (INIS)

    Hermier, J.; Le Guennec, R.

    1984-01-01

    In the first part of this article, J. Hermier covers the use of remote handling equipment in the UP2-400 plant at La Hague near Cherbourg, in which for the most part master/slave mechanism remote handling units are used with a number of these employed in daily processing operations. As regards this subject, it is useful to remember that, at the time of the designing of this plant (UP2-400), this was the only equipment available on the market with remote-controlled remote handling equipment. In the second part, before speaking about the development of remote operation equipment in the plants now under construction and attempting to project what might be the remote operation role in future plants, R. Le Guennec reviews the problems faced by engineering in designing industrial-sized processing plants and, consequently, the motivations of engineering when faced with a choice between several possible solutions [fr

  7. Nuclear pre-mRNA processing in plants

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, A.S.N. [Colorado State Univ., Fort Collins, CO (United States). Dept. of Biology and Program in Molecular Plant Biology; Golovkin, M. (eds.) [Thomas Jefferson Univ., Philadelphia, PA (United States). Dept. of Microbiology

    2008-07-01

    This volume of CTMI, entitled Nuclear premRNA Processing in Plants, with 16 chapters from leading scientists in this area, summarizes recent advances in nuclear pre-mRNA processing and its role in plant growth and development. It provides researchers in the field, as well as those in related areas, with an up-to-date and comprehensive, yet concise, overview of the current status and future potential of this research in understanding plant biology. The first four chapters focus on spliceosome composition, genome-wide alternative splicing, and splice site requirements for U1 and U12 introns using computational and empirical approaches. Analysis of sequenced plant genomes has revealed that 80% of all protein-coding nuclear genes contain one or more introns. The lack of an in vitro plant splicing system has made it difficult to identify general and plant-specific components of splicing machinery in plants. The next three chapters focus on serine/arginine-rich (SR) proteins, a family of highly conserved proteins, which are known to play key roles in constitutive and regulated splicing of pre-mRNA and other aspects of RNA metabolism in metazoans. These proteins engage both in RNA binding and protein.protein interactions and function as splicing regulators at multiple stages of spliceosome assembly. This family of proteins has expanded considerably in plants with several plant-specific SR proteins. Several serendipitous discoveries made using forward genetics are indicating that RNA metabolism (alternative splicing, alternative polyadenylation, mRNA transport) plays an important role in many aspects of plant growth and development and in plant responses to biotic and abiotic stresses. The next seven chapters focus on these aspects of RNA metabolism. The plant hormone abscisic acid (ABA) regulates a number of physiological processes during plant growth and development. The next chapter or A.B. Rose discusses the ways introns affect gene expression both positively and

  8. Nuclear pre-mRNA processing in plants

    International Nuclear Information System (INIS)

    Reddy, A.S.N.; Golovkin, M.

    2008-01-01

    This volume of CTMI, entitled Nuclear premRNA Processing in Plants, with 16 chapters from leading scientists in this area, summarizes recent advances in nuclear pre-mRNA processing and its role in plant growth and development. It provides researchers in the field, as well as those in related areas, with an up-to-date and comprehensive, yet concise, overview of the current status and future potential of this research in understanding plant biology. The first four chapters focus on spliceosome composition, genome-wide alternative splicing, and splice site requirements for U1 and U12 introns using computational and empirical approaches. Analysis of sequenced plant genomes has revealed that 80% of all protein-coding nuclear genes contain one or more introns. The lack of an in vitro plant splicing system has made it difficult to identify general and plant-specific components of splicing machinery in plants. The next three chapters focus on serine/arginine-rich (SR) proteins, a family of highly conserved proteins, which are known to play key roles in constitutive and regulated splicing of pre-mRNA and other aspects of RNA metabolism in metazoans. These proteins engage both in RNA binding and protein.protein interactions and function as splicing regulators at multiple stages of spliceosome assembly. This family of proteins has expanded considerably in plants with several plant-specific SR proteins. Several serendipitous discoveries made using forward genetics are indicating that RNA metabolism (alternative splicing, alternative polyadenylation, mRNA transport) plays an important role in many aspects of plant growth and development and in plant responses to biotic and abiotic stresses. The next seven chapters focus on these aspects of RNA metabolism. The plant hormone abscisic acid (ABA) regulates a number of physiological processes during plant growth and development. The next chapter or A.B. Rose discusses the ways introns affect gene expression both positively and

  9. New development of spectrophotometric analysis of thorium

    International Nuclear Information System (INIS)

    Yang Xiangzhen

    1992-01-01

    This review covers new development of spectrophotometric determination of thorium since 1980's. The methods include general spectrophotometry, double wavelength spectrophotometry, catalytic spectrophotometry, total differential spectrophotometry, derivative spectrophotometry and fluorescent spectrophotometry, etc

  10. Geochemical prospecting for uranium and thorium deposits

    International Nuclear Information System (INIS)

    Boyle, R.W.

    1980-01-01

    A brief review of analytical geochemical prospecting methods for uranium and thorium is given excluding radiometric techniques, except those utilized in the determination of radon. The indicator (pathfinder) elements useful in geochemical surveys are listed for each of the types of known uranium and thorium deposits; this is followed by sections on analytical geochemical surveys based on rocks (lithochemical surveys), unconsolidated materials (pedochemical surveys), natural waters and sediments (hydrochemical surveys), biological materials (biogeochemical surveys) and gases (atmochemical surveys). All of the analytical geochemical methods are applicable in prospecting for thorium and uranium, particularly where radiometric methods fail due to attenuation by overburden, water, deep leaching and so on. Efficiency in the discovery of uranium and/or thorium orebodies is promoted by an integrated methods approach employing geological pattern recognition in the localization of deposits, analytical geochemical surveys, and radiometric surveys. (author)

  11. Titanium(IV), zirconium, hafnium and thorium

    International Nuclear Information System (INIS)

    Brown, Paul L.; Ekberg, Christian

    2016-01-01

    Titanium can exist in solution in a number of oxidation states. The titanium(IV) exists in acidic solutions as the oxo-cation, TiO 2+ , rather than Ti 4+ . Zirconium is used in the ceramics industry and in nuclear industry as a cladding material in reactors where its reactivity towards hydrolysis reactions and precipitation of oxides may result in degradation of the cladding. In nature, hafnium is found together with zirconium and as a consequence of the contraction in ionic radii that occurs due to the 4f -electron shell, the ionic radius of hafnium is almost identical to that of zirconium. All isotopes of thorium are radioactive and, as a consequence of it being fertile, thorium is important in the nuclear fuel cycle. The polymeric hydrolysis species that have been reported for thorium are somewhat different to those identified for zirconium and hafnium, although thorium does form the Th 4 (OH) 8 8+ species.

  12. Extraction of thorium from solution using tribenzylamine

    International Nuclear Information System (INIS)

    Whitehead, N.E.; Ditchburn, R.G.

    1975-01-01

    A method is described for isolating thorium from solutions in a state sufficiently pure for alpha spectroscopy. It parallels the method described by Moore and Thern (Radiochemical Radioanalytical Letters 19(2), 117-125, 1974), but uses tribenzylamine instead of Adogen 364. The method involves extracting thorium from a solution in 8M nitric acid, into a 6% w/v solution of tribenzylamine in toluene. The thorium is concentrated in a third, interfacial layer which forms. This layer is isolated, diluted with chloroform, and back extracted with 10M HC1. Overall yields range between 83 and 90% for one extraction. The acidic solution is taken down to near dryness, diluted until the pH is 2 and extracted into 1.2 ml of thenoyltrifluoroacetone in toluene. This solution is evaporated onto a stainless steel disk, flamed, and the disk may be used for alpha spectroscopy of thorium isotopes. (auth.)

  13. Polarographic determination of trace amounts of thorium

    Energy Technology Data Exchange (ETDEWEB)

    Zaofan Zhao; Xiaohua Cai; Peibiao Li; Handong Yang

    1986-07-01

    A sensitive linear-sweep polarographic method for the determination of thorium is described. It is based on the thorium complex with Xylidyl Blue I (XBI) in a medium containing ethylenediamine, 1, 10-phenanthroline, oxalic acid and ninhydrin, at pH 10.5-11.5. The complex has been proved to be Th(XBI)/sub 2/, with log ..beta..'=9.6. The method can be used to determine trace amounts of thorium over the range 3.5x10/sup -8/-3x10/sup -6/M. The detection limit is 1x10/sup -8/M. A solvent extraction procedure is necessary to eliminate interference from several cations. The method has been applied to determination of traces of thorium in minerals, with good results.

  14. Parametric study of a thorium model

    International Nuclear Information System (INIS)

    Lourenco, M.C.; Lipsztein, J.L.; Szwarcwald, C.L.

    2002-01-01

    Models for radionuclides distribution in the human body and dosimetry involve assumptions on the biokinetic behavior of the material among compartments representing organs and tissues in the body. One of the most important problem in biokinetic modeling is the assignment of transfer coefficients and biological half-lives to body compartments. In Brazil there are many areas of high natural radioactivity, where the population is chronically exposed to radionuclides of the thorium series. The uncertainties of the thorium biokinetic model are a major cause of uncertainty in the estimates of the committed dose equivalent of the population living in high background areas. The purpose of this study is to discuss the variability in the thorium activities accumulated in the body compartments in relation to the variations in the transfer coefficients and compartments biological half-lives of a thorium-recycling model for continuous exposure. Multiple regression analysis methods were applied to analyze the results. (author)

  15. B Plant process piping replacement feasibility study

    International Nuclear Information System (INIS)

    Howden, G.F.

    1996-01-01

    Reports on the feasibility of replacing existing embedded process piping with new more corrosion resistant piping between cells and between cells and a hot pipe trench of a Hanford Site style canyon facility. Provides concepts for replacement piping installation, and use of robotics to replace the use of the canyon crane as the primary means of performing/supporting facility modifications (eg, cell lining, pipe replacement, equipment reinstallation) and operational maintenenace

  16. Process and plant for manipulating radioactive waste

    International Nuclear Information System (INIS)

    Baatz, H.; Rittscher, D.

    1979-01-01

    To prepare waste for engineered storage, it is vitrified or calcined (pelleted) into solid pieces in a hot cell. Subsequently the pieces are filled into a radiation protection container made of spherulite cast iron, in which there is a liquid metal. The pieces are embedded in this metal matrix. During the embedding process, the radiation protection container may be heated externally or internally (lost heat device). (DG) [de

  17. Alarm processing system using AI techniques for nuclear power plant

    International Nuclear Information System (INIS)

    Yang, Joon On; Chang, Soon Heung

    1990-01-01

    An alarm processing system (APS) has been developed using artificial intelligence (AI) techniques. The alarms of nuclear power plants (NPP's) are classified into the generalized and special alarms. The generalized alarms are also classified into the global and local alarms. For each type of alarms, the specific processing rules are applied to filter and suppress unnecessary and potentially misleading alarms. The local processing are based on 'model-based reasoning.' The global and special alarms are processed by using the general cause-consequence check rules. The priorities of alarms are determined according to the plant state and the consistencies between them

  18. AI-based alarm processing for a nuclear power plant

    International Nuclear Information System (INIS)

    Na, N.J.; Kim, I.S.; Hwang, I.K.; Lee, D.Y.; Ham, C.S.

    1996-01-01

    A real-time expert system is implemented using artificial intelligence and object-oriented technology for alarm processing and presentation in a nuclear power plant. The knowledge base is constructed based on some schemes to process and display alarms to the plant operators. The activated alarms are dynamically prioritized by the reasoning rules, and then, presented on the process mimic overview and by some other means. To demonstrate the proposed system, the alarm processing and presentation is carried out in a simulated environment of the TMI-2 accident

  19. Environmental impact of radioactive releases from recycle of thorium-based fuel using current containment technology

    International Nuclear Information System (INIS)

    Tennery, V.J.; Bomar, E.S.; Bond, W.D.; Morse, L.E.; Meyer, H.R.; Till, J.E.; Yalcintas, M.G.

    1980-01-01

    The analysis of thorium mining and milling suggests that the resulting doses should be similar to those from uranium operations. An absolute comparison cannot be made at this time, however, due to differences in some assumptions utilized by the various investigators and the lack in some cases of site-specific meteorology and population data at thorium resource sites in the western United States. A distinct difference resulting from the short half-life of 220 Rn (T/sub 1/2/ = 55.6 s) in the thorium decay chain compared to that for 222 Rn (T/sub 1/2/ = 3.82 d) in uranium decay was noted for emissions following mill shutdown. This effect is to make potential releases following thorium mill shutdown of lesser consequence than in the uranium case. Thorium tailings activity would also decrease relatively rapidly due to the comparatively short half-life (T/sub 1/2 = 5.75 y) of 228 Ra. Doses due to airborne releases from thorium-uranium carbide fuel refabrication are significantly less than that due to fuel reprocessing. Tritium is the principal contributor to reprocessing plant doses while carbon-14, 131 Cs, and 232 U account for most of the remaining dose. A tenfold increase in reprocessing plant CF for tritium reduces both individual and population doses by about 60%. For refabrication operations, a near linear dependence upon dose with 232 U content of the fuel was calculated between concentrations of 10 ppM and 5000 ppM. Comparison of (Th, U)C and (U, Pu)C showed little difference in dose commitment, but the presence of 232 U in the (Th, U) fuel causes a notable increase in the refabrication plant dose over that previously calculated for (U, Pu) type fuels

  20. Uranium and thorium migration under dislocative metamorphism

    International Nuclear Information System (INIS)

    Titov, V.K.; Bilibina, T.V.; Dashkova, A.D.; Il'in, V.K.; Makarova, L.I.; Shmuraeva, L.Ya.

    1978-01-01

    Investigated were peculiarities of uranium and thorium behaviour in the process of dislocation metamorphism on the basis of regional fracture zones of early-proterozoic embedding of Ukrainian, Aldan and Baltic shields. The studied zones correspond to tectonite of green-shale and almandin-amphibolite facies of regional metamorphism according to mineral associations. The most peculiar feature of the tectonites of green-shale facies is uranium presence in migrationally able forms, which can be involved afterwards into the ore process by hydrothermal solutions. Adsorved forms of uranium on the crystal surface or separate grains and in the cracks, as well as microinclusions of uranium minerals, selectively timed to mineral structure defects prevail among easily mobile uranium compounds. Dissolved uranium is present, evidently in gas-liquid inclusions in minerals and pore waters. There forms of uranium presence are peculiar for epidote-chlorite mylonites, as well as cataclasites and diaphthorites related to them by blastomylonites of almandin-amphibolite facies. Wide range of manifestation of this process, caused by multikilometer extension of deep fracture zones permit to consider the formations of green-shale facies of dislocation metamorphism as one of the main uranium sources in deposit formation in different uranium-ore associations different age

  1. Comparison for thorium fuel cycle facilities of two different capacities for implementation of safeguards

    International Nuclear Information System (INIS)

    Gangotra, Suresh; Grover, R.B.; Ramakumar, K.L.

    2013-01-01

    Highlights: • Facilities for implementation of safeguards for thorium fuel cycle have been compared. • Two concepts have been compared. • In one concept, the facilities are designed in hub and spoke concept. • In second concept the facilities are designed as self-contained concept. • The comparison is done on a number of factors, which affect safeguardability and proliferation resistance. -- Abstract: Thorium based nuclear fuel cycle has many attractive features, its inherent proliferation resistance being one of them. This is due to the presence of high energy gamma emitting daughter products of U 232 associated with U 233 . This high energy gamma radiation also poses challenges in nuclear material accounting. A typical thorium fuel cycle facility has a number of plants including a fuel fabrication plant for initial and equilibrium core, a reprocessed U 233 fuel fabrication plant, a reprocessing plant, a fuel assembly/disassembly plant and associated waste handling and management plants. A thorium fuel cycle facility can be set up to serve reactors at a site. Alternatively, one can follow a hub and spoke approach with a large thorium fuel cycle facility acting as a hub, catering to the requirements of reactors at several sites as spokes. These two concepts have their respective merits and shortcomings in terms of engineering and economics. The present paper is aimed at comparing the merits and challenges for implementation of safeguards on the two concepts viz. a large fuel cycle hub catering to reactors at several sites versus a small fuel cycle facility dedicated to reactors at a single site

  2. Comparison for thorium fuel cycle facilities of two different capacities for implementation of safeguards

    Energy Technology Data Exchange (ETDEWEB)

    Gangotra, Suresh, E-mail: sgangotra@yahoo.co.in; Grover, R.B.; Ramakumar, K.L.

    2013-09-15

    Highlights: • Facilities for implementation of safeguards for thorium fuel cycle have been compared. • Two concepts have been compared. • In one concept, the facilities are designed in hub and spoke concept. • In second concept the facilities are designed as self-contained concept. • The comparison is done on a number of factors, which affect safeguardability and proliferation resistance. -- Abstract: Thorium based nuclear fuel cycle has many attractive features, its inherent proliferation resistance being one of them. This is due to the presence of high energy gamma emitting daughter products of U{sup 232} associated with U{sup 233}. This high energy gamma radiation also poses challenges in nuclear material accounting. A typical thorium fuel cycle facility has a number of plants including a fuel fabrication plant for initial and equilibrium core, a reprocessed U{sup 233} fuel fabrication plant, a reprocessing plant, a fuel assembly/disassembly plant and associated waste handling and management plants. A thorium fuel cycle facility can be set up to serve reactors at a site. Alternatively, one can follow a hub and spoke approach with a large thorium fuel cycle facility acting as a hub, catering to the requirements of reactors at several sites as spokes. These two concepts have their respective merits and shortcomings in terms of engineering and economics. The present paper is aimed at comparing the merits and challenges for implementation of safeguards on the two concepts viz. a large fuel cycle hub catering to reactors at several sites versus a small fuel cycle facility dedicated to reactors at a single site.

  3. Arbuscular mycorrhiza reduces phytoextraction of uranium, thorium and other elements from phosphate rock

    DEFF Research Database (Denmark)

    Roos, Per; Jakobsen, Iver

    2008-01-01

    Uptake of metals from uranium-rich phosphate rock was studied in Medicago truncatula plants grown in symbiosis with the arbuscular mycorrhizal fungus Glomus intraradices or in the absence of mycorrhizas. Shoot concentrations of uranium and thorium were lower in mycorrhizal than in non-mycorrhizal......-fungus uptake systems. The results support the role of arbuscular mycorrhiza as being an important component in phytostabilization of uranium. This is the first study to report on mycorrhizal effect and the uptake and root-to-shoot transfer of thorium from phosphate rock. (c) 2007 Elsevier Ltd. All rights...

  4. Stepwise hydrochloric acid extraction of monazite hydroxides for the recovery of cerium lean rare earths, cerium, uranium and thorium

    International Nuclear Information System (INIS)

    Swaminathan, T.V.; Nair, V.R.; John, C.V.

    1988-01-01

    Monazite sand is normally processed by the caustic soda route to produce mixed rare earth chloride, thorium hydroxide and trisodium phosphate. Bulk of the mixed rare earth chloride is used for the preparation of FC catalysts. Recently some of the catalyst producers have shown preference to cerium depleted (lanthanum enriched) rare earth chloride rather than the natural rare earth chloride obtained from monazite. Therefore, a process for producing cerium depleted rare earth chloride, cerium, thorium and uranium from rare earth + thorium hydroxide obtained by treating monazite, based on stepwise hydrochloric acid extraction, was developed in the authors laboratory. The process involves drying of the mixed rare earth-thorium hydroxide cake obtained by monazite-caustic soda process followed by stepwise extraction of the dried cake with hydrochloric acid under specified conditions

  5. IMPROVING TACONITE PROCESSING PLANT EFFICIENCY BY COMPUTER SIMULATION, Final Report

    Energy Technology Data Exchange (ETDEWEB)

    William M. Bond; Salih Ersayin

    2007-03-30

    This project involved industrial scale testing of a mineral processing simulator to improve the efficiency of a taconite processing plant, namely the Minorca mine. The Concentrator Modeling Center at the Coleraine Minerals Research Laboratory, University of Minnesota Duluth, enhanced the capabilities of available software, Usim Pac, by developing mathematical models needed for accurate simulation of taconite plants. This project provided funding for this technology to prove itself in the industrial environment. As the first step, data representing existing plant conditions were collected by sampling and sample analysis. Data were then balanced and provided a basis for assessing the efficiency of individual devices and the plant, and also for performing simulations aimed at improving plant efficiency. Performance evaluation served as a guide in developing alternative process strategies for more efficient production. A large number of computer simulations were then performed to quantify the benefits and effects of implementing these alternative schemes. Modification of makeup ball size was selected as the most feasible option for the target performance improvement. This was combined with replacement of existing hydrocyclones with more efficient ones. After plant implementation of these modifications, plant sampling surveys were carried out to validate findings of the simulation-based study. Plant data showed very good agreement with the simulated data, confirming results of simulation. After the implementation of modifications in the plant, several upstream bottlenecks became visible. Despite these bottlenecks limiting full capacity, concentrator energy improvement of 7% was obtained. Further improvements in energy efficiency are expected in the near future. The success of this project demonstrated the feasibility of a simulation-based approach. Currently, the Center provides simulation-based service to all the iron ore mining companies operating in northern

  6. Determination of Properties of Selected Fresh and Processed Medicinal Plants

    Directory of Open Access Journals (Sweden)

    Shirley G. Cabrera

    2015-11-01

    Full Text Available The study aimed to determine the chemical properties, bioactive compounds, antioxidant activity and toxicity level of fresh and processed medicinal plants such as corn (Zea mays silk, pancitpancitan (Peperomiapellucida leaves, pandan (Pandanus amaryllifolius leaves, and commercially available tea. The toxicity level of the samples was measured using the Brine Shrimp Lethality Assay (BSLA. Statistical analysis was done using Statistical Package for Social Sciences (SPSS. Results showed that in terms of chemical properties there is significant difference between fresh and processed corn silk except in crude fiber content was noted. Based on proximate analyses of fresh and processed medicinal plants specifically in terms of % moisture, %crude protein and % total carbohydrates were also observed. In addition, there is also significant difference on bioactive compound contents such as total flavonoids and total phenolics between fresh and processed corn silk except in total vitamin E (TVE content. Pandan and pancit-pancitan showed significant difference in all bioactive compounds except in total antioxidant content (TAC. Fresh pancit-pancitan has the highest total phenolics content (TPC and TAC, while the fresh and processed corn silk has the lowest TAC and TVE content, respectively. Furthermore, results of BSLA for the three medicinal plants and commercially available tea extract showed after 24 hours exposure significant difference in toxicity level was observed. The percentage mortality increased with an increase in exposure time of the three medicinal plants and tea extract. The results of the study can served as baseline data for further processing and commercialization of these medicinal plants.

  7. Long-term health effects of thorium compounds on exposed workers: the complete blood count

    International Nuclear Information System (INIS)

    Conibear, S.A.

    1981-01-01

    Two hundred seventy-three men exposed to thorium and other rare earths between 1940 and 1973 at a plant which refined monazite sand were studied at Argonne National Laboratory from 1976 to 1980. In vivo measurements of body burden were made by counting gamma rays emitted by daughter products of retained thorium and by measuring exhaled thoron. Health status was ascertained through questionnaire, physical examination, and clinical laboratory tests. Measured body burden was found to be higher in those with a history of longer exposure. All parameters of the complete blood count were examined for evidence of an effect due to thorium. Comparisons of high and low body burden groups showed that only age and cigarette smoking had an effect on complete blood count parameters

  8. Financial Benefits of Process Data Reconciliation in Power Generating Plants

    International Nuclear Information System (INIS)

    Jansky, Andy

    2006-01-01

    Process Data Reconciliation (PDR) is a certified method that calculates the most likely values considering process measurement uncertainties and closing all energy- and material balances where all inter-dependencies within the entire plant process are fulfilled in a covariance matrix. There are three main factors that generate the financial benefits for the user of reconciled data, depending on the type of plant and base/peak load behaviour: Increased efficiency / maximized output, Time advantage in retrieving 'lost' megawatts, Reduction of maintenance costs. (author)

  9. Thorium and health: state of the art; Thorium et sante: etat de l'art

    Energy Technology Data Exchange (ETDEWEB)

    Leiterer, A.; Berard, Ph.; Menetrier, F.

    2010-07-01

    This report reviews data available in the literature on the subject: 'thorium and health'. Thorium is a natural radioactive element of the actinide series. It is widely distributed in the earth's crust and 99% is found as isotope thorium-232. Its various uses are explained by its chemical, physical, and nuclear properties. As a potential nuclear fuel, thorium is still in demonstration in pilot scale reactors. But thorium has already multiple and sometimes unknown industrial uses. Some mass market products are concerned like light bulb. This raises the issue of wastes, and of exposures of workers and public. Environmental exposure via food and drink of the general population is low, where as workers can be exposed to significant doses, especially during ore extraction. Data on bio-monitoring of workers and biokinetic of thorium, in particular those provided by ICRP, are gathered here. Studies on health effects and toxicity of thorium are scarce and mostly old, except outcomes of its previous medical use. Studies on other forms of thorium should be undertaken to provide substantial data on its toxicity. Concerning treatment, Ca-DTPA is the recommended drug even if its efficacy is moderate. LiHOPO molecule shows interesting results in animals, and further research on chelating agents is needed. (authors)

  10. Chemical process and plant design bibliography 1959-1989

    International Nuclear Information System (INIS)

    Ray, M.S.

    1991-01-01

    This book is concerned specifically with chemical process in formation and plant equipment design data. It is a source for chemical engineers, students and academics involved in process and design evaluation. Over 500 chemical categories are included, from Acetaldehyde to zirconium Dioxide, with cross-referencing within the book to appropriate associated chemicals

  11. Process simulation of heavy water plants - a powerful analytical tool

    International Nuclear Information System (INIS)

    Miller, A.I.

    1978-10-01

    The commercially conscious designs of Canadian GS (Girdler-Sulphide) have proved sensitive to process conditions. That, combined with the large scale of our units, has meant that computer simulation of their behaviour has been a natural and profitable development. Atomic Energy of Canada Limited has developed a family of steady state simulations to describe all of the Canadian plants. Modelling of plant conditions has demonstrated that the simulation description is very precise and it has become an integral part of the industry's assessments of both plant operation and decisions on capital expenditures. The simulation technique has also found extensive use in detailed designing of both the rehabilitated Glace Bay and the new La Prade plants. It has opened new insights into plant design and uncovered a radical and significant flowsheet change for future designs as well as many less dramatic but valuable lesser changes. (author)

  12. Multilevel flow modelling of process plant for diagnosis and control

    International Nuclear Information System (INIS)

    Lind, M.

    1982-08-01

    The paper describes the multilevel flow modelling methodology which can be used to construct functional models of energy and material processing systems. The models describe mass and energy flow topology on different levels of abstraction and represent the hierarchical functional structure of complex systems. A model of a nuclear power plant (PWR) is presented in the paper for illustration. Due to the consistency of the method, multilevel flow models provide specifications of plant goals and functions and may be used as a basis for design of computer-based support systems for the plant operator. Plant control requirements can be derived from the models and due to independence of the actual controller implementation the method may be used as basic for design of control strategies and for the allocation of control tasks to the computer and the plant operator. (author)

  13. Multilevel Flow Modelling of Process Plant for Diagnosis and Control

    DEFF Research Database (Denmark)

    Lind, Morten

    1982-01-01

    The paper describes the multilevel flow modelling methodology which can be used to construct functional models of energy and material processing systems. The models describe mass and energy flow topology on different levels of abstraction and represent the hierarchical functional structure...... of complex systems. A model of a nuclear power plant (PWR) is presented in the paper for illustration. Due to the consistency of the method, multilevel flow models provide specifications of plant goals and functions and may be used as a basis for design of computer-based support systems for the plant...... operator. Plant control requirements can be derived from the models and due to independence of the actual controller implementation the method may be used as a basis for design of control strategies and for the allocation of control tasks to the computer and the plant operator....

  14. Vacuolar processing enzyme: an executor of plant cell death.

    Science.gov (United States)

    Hara-Nishimura, Ikuko; Hatsugai, Noriyuki; Nakaune, Satoru; Kuroyanagi, Miwa; Nishimura, Mikio

    2005-08-01

    Apoptotic cell death in animals is regulated by cysteine proteinases called caspases. Recently, vacuolar processing enzyme (VPE) was identified as a plant caspase. VPE deficiency prevents cell death during hypersensitive response and cell death of limited cell layers at the early stage of embryogenesis. Because plants do not have macrophages, dying cells must degrade their materials by themselves. VPE plays an essential role in the regulation of the lytic system of plants during the processes of defense and development. VPE is localized in the vacuoles, unlike animal caspases, which are localized in the cytosol. Thus, plants might have evolved a regulated cellular suicide strategy that, unlike animal apoptosis, is mediated by VPE and the vacuoles.

  15. The Relation of Design Parameters, Plant Capacity and Processing Costs in Cobalt-60 Sterilization Plants

    International Nuclear Information System (INIS)

    Brown, M.G.

    1967-01-01

    The paper describes the main features of three basic types of cobalt-60 sterilization plants which have been designed to provide a complete range of capacities for radiosterilization of medical products. The smallest plant has a capacity of up to 50 000 cubic feet of medical products a year, the intermediate size plant has a capacity of up to 500 000 cubic feet a year, and the largest plant has a capacity in excess of 1000 000 cubic feet a year. The relations between capital costs, rate of production, efficiency and unit processing costs for each type of plant are discussed. The method of selecting the best type of plant for a particular need will also be outlined. (author)

  16. Radiation processing of minimally processed vegetables and aromatic plants

    International Nuclear Information System (INIS)

    Trigo, M.J.; Sousa, M.B.; Sapata, M.M.; Ferreira, A.; Curado, T.; Andrada, L.; Botelho, M.L.; Veloso, M.G.

    2009-01-01

    Vegetables are an essential part of people's diet all around the world. Due to cultivate techniques and handling after harvest, these products, may contain high microbial load that can cause food borne outbreaks. The irradiation of minimally processed vegetables is an efficient way to reduce the level of microorganisms and to inhibit parasites, helping a safe global trade. Evaluation of the irradiation's effects was carried out in minimal processed vegetables, as coriander (Coriandrum sativum L.), mint (Mentha spicata L.), parsley (Petroselinum crispum Mill, (A.W. Hill)), lettuce (Lactuca sativa L.) and watercress (Nasturium officinale L.). The inactivation level of natural microbiota and the D 10 values of Escherichia coli O157:H7 and Listeria innocua in these products were determined. The physical-chemical and sensorial characteristics before and after irradiation at a range of 0.5 up to 2.0 kGy applied doses were also evaluated. No differences were verified in the overall of sensorial and physical properties after irradiation up to 1 kGy, a decrease of natural microbiota was noticed (≥2 log). Based on the determined D 10 , the amount of radiation necessary to kill 10 5 E. coli and L. innocua was between 0.70 and 1.55 kGy. Shelf life of irradiated coriander, mint and lettuce at 0.5 kGy increased 2, 3 and 4 days, respectively, when compared with non-irradiated.

  17. Radiation processing of minimally processed vegetables and aromatic plants

    Energy Technology Data Exchange (ETDEWEB)

    Trigo, M.J. [Instituto Nacional dos Recursos Biologicos, L-INIA, Quinta do Marques, 2784-505 Oeiras (Portugal)], E-mail: mjptrigo@gmail.com; Sousa, M.B.; Sapata, M.M.; Ferreira, A.; Curado, T.; Andrada, L. [Instituto Nacional dos Recursos Biologicos, L-INIA, Quinta do Marques, 2784-505 Oeiras (Portugal); Botelho, M.L. [Instituto Tecnologico e Nuclear, E.N. 10, 2696 Sacavem (Portugal); Veloso, M.G. [Faculdade de Medicina Veterinaria de Lisboa, Av. da Universidade Tecnica, Alto da Ajuda, 1300-477 Lisboa (Portugal)

    2009-07-15

    Vegetables are an essential part of people's diet all around the world. Due to cultivate techniques and handling after harvest, these products, may contain high microbial load that can cause food borne outbreaks. The irradiation of minimally processed vegetables is an efficient way to reduce the level of microorganisms and to inhibit parasites, helping a safe global trade. Evaluation of the irradiation's effects was carried out in minimal processed vegetables, as coriander (Coriandrum sativum L.), mint (Mentha spicata L.), parsley (Petroselinum crispum Mill, (A.W. Hill)), lettuce (Lactuca sativa L.) and watercress (Nasturium officinale L.). The inactivation level of natural microbiota and the D{sub 10} values of Escherichia coli O157:H7 and Listeria innocua in these products were determined. The physical-chemical and sensorial characteristics before and after irradiation at a range of 0.5 up to 2.0 kGy applied doses were also evaluated. No differences were verified in the overall of sensorial and physical properties after irradiation up to 1 kGy, a decrease of natural microbiota was noticed ({>=}2 log). Based on the determined D{sub 10}, the amount of radiation necessary to kill 10{sup 5}E. coli and L. innocua was between 0.70 and 1.55 kGy. Shelf life of irradiated coriander, mint and lettuce at 0.5 kGy increased 2, 3 and 4 days, respectively, when compared with non-irradiated.

  18. Radiation processing of minimally processed vegetables and aromatic plants

    Science.gov (United States)

    Trigo, M. J.; Sousa, M. B.; Sapata, M. M.; Ferreira, A.; Curado, T.; Andrada, L.; Botelho, M. L.; Veloso, M. G.

    2009-07-01

    Vegetables are an essential part of people's diet all around the world. Due to cultivate techniques and handling after harvest, these products, may contain high microbial load that can cause food borne outbreaks. The irradiation of minimally processed vegetables is an efficient way to reduce the level of microorganisms and to inhibit parasites, helping a safe global trade. Evaluation of the irradiation's effects was carried out in minimal processed vegetables, as coriander ( Coriandrum sativum L .), mint ( Mentha spicata L.), parsley ( Petroselinum crispum Mill, (A.W. Hill)), lettuce ( Lactuca sativa L.) and watercress ( Nasturium officinale L.). The inactivation level of natural microbiota and the D 10 values of Escherichia coli O157:H7 and Listeria innocua in these products were determined. The physical-chemical and sensorial characteristics before and after irradiation at a range of 0.5 up to 2.0 kGy applied doses were also evaluated. No differences were verified in the overall of sensorial and physical properties after irradiation up to 1 kGy, a decrease of natural microbiota was noticed (⩾2 log). Based on the determined D10, the amount of radiation necessary to kill 10 5E. coli and L. innocua was between 0.70 and 1.55 kGy. Shelf life of irradiated coriander, mint and lettuce at 0.5 kGy increased 2, 3 and 4 days, respectively, when compared with non-irradiated.

  19. Transformation of thorium sulfate in thorium nitrate by ion exchange resin

    International Nuclear Information System (INIS)

    Pereira, W.

    1991-01-01

    A procedure for transforming thorium sulfate into thorium nitrate by means of a strong cationic ion exchanger is presented. The thorium sulfate solution (approximately 15 g/L Th (SO 4 ) 2 ) is percolate through the resin and the column is washed first with water, with a 0,2 M N H 4 OH solution and then with a 0.2 M N H 4 NO 3 solution in order to eliminate sulfate ion. Thorium is eluted with a 2 M solution of (N H 4 ) 2 CO 3 . This eluate is treated with a solution of nitric acid in order to obtain the complete transformation into Th (NO 3 ) 4 . The proposed procedure leads to good quality thorium nitrate with high uranium decontamination. (author)

  20. Radiological hazards assessment at mineral processing plants in Malaysia

    International Nuclear Information System (INIS)

    Mohd Tadza Abdul Rahman; Shamsul Bahrin Ludin; Mohd Yusof Harun; Amran Kamaruddin; Abdul Hamid Latip; Mohd Azwar Hashim

    1994-01-01

    The estimated total dose due to radiation received by workers at the minerals processing plants in Malaysia based on area monitoring data. The dose was evaluated using three main parameters, namely exposures from external radiation, inhalation of airborne radioactive dusts and radon/thoron progenies. The study shows that workers at different location in the plants are potentially exposed to in excess of one tenth (1/10) and three tenth (3/10) of the annual dose limit. (author)

  1. Thermodynamic analysis of CO2 capture processes for power plants

    OpenAIRE

    Biyouki, Zeinab Amrollahi

    2014-01-01

    This thesis work presents an evaluation of various processes for reducing CO2 emissions from natural-gas-fired combined cycle (NGCC) power plants. The scope of the thesis is to focus mainly on post-combustion chemical absorption for NGCC. For the post-combustion capture plant, an important interface is the steam extraction from the steam turbine in order to supply the heat for solvent regeneration. The steam extraction imposes a power production penalty. The thesis includes analysis and compa...

  2. Nuclear power plant personnel training process management system

    International Nuclear Information System (INIS)

    Arjona Vazquez, Orison; Venegas Bernal, Maria del Carmen; Armeteros Lopez, Ana L.

    1996-01-01

    The system in charge the management of the training process personnel from a nuclear power plant was designed taking into account all the requirements stated in the training guide for nuclear power plant personnel and their evaluation, which were prepared by the IAEA in 1995 in order to implement the SAT in the training programs for nuclear plant personnel. In the preparations of formats and elements that shape the system, account has been taken of the views expressed in such a guide, in some other bibliography that was consulted, and in the authors own opinion mainly with regard to those issues which the guide does not go deeper into

  3. Site layout and balance of plant design for an accelerator-driven materials processing complex

    Energy Technology Data Exchange (ETDEWEB)

    Cunliffe, J.; Taussig, R.; Ghose, S. [Bechtel Corporation, San Francisco, CA (United States)] [and others

    1995-10-01

    High energy proton beam accelerators are under consideration for use in radioisotope production, surplus weapons material destruction, radioactive waste transmutation, and thorium-based energy conversion cycles. While there are unique aspects to each of these applications that must be accommodated in the design of the associated facility, all share a set of fundamental characteristics that in large measure dictate the site layout features and many balance-of-plant (BOP) design requirements found to be common to all. This paper defines these key design determinants and goes on to discuss the manner in which they have been accommodated in the pre-conceptual design for a particular materials production application. An estimate of the costs associated with this BOP design is also presented with the aim of guiding future evaluations where the basic plant designs are similar to that of this specific case.

  4. Study on removal technology for thorium in the waste gas-lamp mantle

    International Nuclear Information System (INIS)

    Shi Yucheng; Wang Chengbao; Zhang Ping; Xu Lingqi; Jiang Shangen

    1999-01-01

    The author describes thorium removal technology and its application in the handling of the waste gas-lamp mantle that produced during the production of gas-lamp process. After laboratory test, pilot test, trial run and engineering scale use, the thorium removal technology is mainly as follows: soak the waste gas-lamp mantle into the ceramic vat with the nitric acid solution twice and wash it with the tap water twice. The volume of the ceramic vat is 500 L and the concentration of the nitric acid solution is 2 mol/L. After handling, the thorium removal rate can reach 99.97% and the residual thorium will be less than 160 Bq/kg. The waste gas-lamp mantle can be buried under the ground or be handled in the other ways just as the harmless waste. The nitric acid solution, in which gas-lamp mantle has been soaked, should be extracted with TBP, then back extracted with diluted hydrochloric acid. After supplementing the thorium nitrate into the back extracted liquid, the liquid can be reused in the gas-lamp mantle production. The waste water from the handling process can be handled together with waste water from production process

  5. A contractor's approach to engineering process plant for radioactive liquor processing

    International Nuclear Information System (INIS)

    Braide, W.M.; Fletcher, P.D.

    1982-01-01

    Protection of personnel from damaging sources of radiation is the overriding consideration which influences the fundamental design of plant for processing active liquors in the Nuclear Industry. The conventional design procedures of the Chemical Plant Contractor have therefore to be modified to meet the specific technology and additional safety requirements. Ways in which the added factor of radiation influences the design philosophy for Nuclear Plant compared to conventional Chemical Plant are described. Design philosophy is demonstrated by design studies for active liquor storage and evaporation plant. (author)

  6. A contractors's approach to engineering process plant for radioactive liquor processing

    International Nuclear Information System (INIS)

    Braide, W.M.; Fletcher, P.D.

    1982-01-01

    Protection of personnel from damaging sources of radiation is the overriding consideration which influences the fundamental design of plant for processing active liquors in the Nuclear Industry. The conventional design procedures of the Chemical Plant Contractor have therefore to be modified to meet the specific technology and additional safety requirements. This paper describes ways in which the added factor of radiation influences the design philosophy for Nuclear Plant compared to conventional Chemical Plant. The design philosophy is demonstrated by design studies for active liquor storage and evaporation plant. (author)

  7. Continuous precipitation of uranium peroxide in process pilot plant

    International Nuclear Information System (INIS)

    Quinelato, A.L.

    1990-01-01

    An experimental study on uranium peroxide precipitation has been carried out with the objective to evaluate the influence of the main process parameters with a technological approach. The uraniferous solution used was obtained from the hydrometallurgical processing of an ore from Itataia - CE. Studies were developed in two distinct experimental stages. In the first stage, the precipitation was investigated by means of laboratory batch tests and, in the second stage, by means of continuous operation in a process pilot plant. (author)

  8. Photon attenuation properties of some thorium, uranium and plutonium compounds

    Energy Technology Data Exchange (ETDEWEB)

    Singh, V. P.; Badiger, N. M. [Karnatak University, Department of Physics, Dharwad-580003, Karnataka (India); Vega C, H. R., E-mail: kudphyvps@rediffmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico)

    2015-10-15

    Mass attenuation coefficients, effective atomic numbers, effective electron densities for nuclear materials; thorium, uranium and plutonium compounds have been studied. The photon attenuation properties for the compounds have been investigated for partial photon interaction processes by photoelectric effect, Compton scattering and pair production. The values of these parameters have been found to change with photon energy and interaction process. The variations of mass attenuation coefficients, effective atomic number and electron density with energy are shown graphically. Moreover, results have shown that these compounds are better shielding and suggesting smaller dimensions. The study would be useful for applications of these materials for gamma ray shielding requirement. (Author)

  9. Binary and ternary photofission of thorium 232

    Energy Technology Data Exchange (ETDEWEB)

    Titterton, E W; Brinkley, T A

    1950-05-01

    Work by Titterton and Goward (1949) has shown that uranium undergoes photofission into three charged fragments. Experiments have been conducted to determine whether a similar process takes place in the photofission of thorium. Some difficulties were encountered in loading plates with /sup 232/Th atoms, but this was finally accomplished by means of a technique described in detail. Plates loaded by this method were irradiated with a continuous spectrum of ..gamma.. rays of maximum energy 24 MeV from the (Atomic Energy Research Establishment) Synchrotron. Three irradiations, of 100, 150, and 180 r, were made and the resulting plates showed a fission density of 2.5 x 10/sup 4//cc at the 150 r level. In an examination involving 2500 binary photofissions, 5 cases of ternary fission involving the emission of a long range light fragment, probably an ..cap alpha..-particle, were observed. These events are described. A number-range curve was determined for the photofission tracks and is compared with a similar curve for tracks formed by the slow neutron fission of /sup 235/U in a D/sub 1/ emulsion under conditions of similar emulsion sensitivity. It appears that the energy release in the photofission of /sup 232/Th is smaller than that in the slow neutron fission of /sup 235/U. The data indicate that 124 MeV is the mean kinetic energy released in the photofission of /sup 232/Th.

  10. Growth of Radiation Processing Plant, Vashi - an overview

    International Nuclear Information System (INIS)

    Singh, Ranjeet

    2014-01-01

    Radiation Processing Plant, Vashi (RPP) is the first commercial scale Gamma Irradiator for food processing in India. The facility was commissioned on 1 st January 2000 with the mandate of showcasing commercial viability of food processing using gamma radiation. Some of the food products that are processed at RPP, Vashi include dehydrated onion powder, coriander, turmeric, black pepper, cumin, pet food and dried seafood items. RPP, Vashi is the largest radiation processor of food products in the country. More than 95% of the quantity processed is exported to various countries generating millions of foreign exchange annually

  11. Materials control and accountability at the Idaho Chemical Processing Plant

    International Nuclear Information System (INIS)

    Denning, G.E.; Britschgi, J.J.; Spraktes, F.W.

    1985-01-01

    The ICPP high enriched uranium recovery process has historically been operated as a single Material Balance Area (MBA), with input and output measurement capabilities. Safeguards initiated changes in the last five years have resulted in significant materials control and accountability improvements. Those changes include semi-automation of process accountability measurement, data collection and recording; definition of Sub-MBAs; standard plant cleanouts; and, bimonthly inventory estimates. Process monitoring capabilities are also being installed to provide independent operational procedural compliance verification, process anomaly detection, and enhanced materials traceability. Development of a sensitivity analysis approach to defining process measurement requirements is in progress

  12. Characterization of process air emissions in automotive production plants.

    Science.gov (United States)

    D'Arcy, J B; Dasch, J M; Gundrum, A B; Rivera, J L; Johnson, J H; Carlson, D H; Sutherland, J W

    2016-01-01

    During manufacturing, particles produced from industrial processes become airborne. These airborne emissions represent a challenge from an industrial hygiene and environmental standpoint. A study was undertaken to characterize the particles associated with a variety of manufacturing processes found in the auto industry. Air particulates were collected in five automotive plants covering ten manufacturing processes in the areas of casting, machining, heat treatment and assembly. Collection procedures provided information on air concentration, size distribution, and chemical composition of the airborne particulate matter for each process and insight into the physical and chemical processes that created those particles.

  13. Solid municipal waste processing plants: Cost benefit analysis

    International Nuclear Information System (INIS)

    Gerardi, V.

    1992-01-01

    This paper performs cost benefit analyses on three solid municipal waste processing alternatives with plants of diverse daily outputs. The different processing schemes include: selected wastes incineration with the production of refuse derived fuels; selected wastes incineration with the production of refuse derived fuels and compost; pyrolysis with energy recovery in the form of electric power. The plant daily outputs range from 100 to 300 tonnes for the refuse derived fuel alternatives, and from 200 to 800 tonnes for the pyrolysis/power generation scheme. The cost analyses consider investment periods of fifteen years in duration and interest rates of 5%

  14. Floating natural gas processing plants. Technical ideal or feasible technology

    Energy Technology Data Exchange (ETDEWEB)

    Backhaus, H

    1977-04-01

    Realizability of floating natural gas processing plants is decisively influenced by the economy of the system. Illustrated by the example of the natural gas product LPG (liquefied petroleum gas), a model cost calculation is carried out. It is demonstrated that the increase in the price level during the 1973/1974 energy crisis is an important factor for the realiability in terms of economy of such complicated technical systems. Another aspect which the model calculation revealed is that the economy of floating natural gas processing plants and storage systems can only be estimated in connection with other system components.

  15. Purex process operation and performance: 1970 thoria campaign

    International Nuclear Information System (INIS)

    Walser, R.L.

    1978-02-01

    The Hanford Purex Plant has demonstrated suitability for reprocessing irradiated thoria (ThO 2 ) target elements on a campaign basis. A 1965 process test and major production campaigns conducted in 1966 and 1970 recovered nitrate solution form products totaling approximately 565 tons of thorium and 820 kilograms of 233 U. The overall recoveries for the 1970 campaign based on reactor input data were 94.9 percent for thorium and 95.2 percent for uranium. The primary function of the Hanford Purex Plant is reprocessing of irradiated uranium fuel elements to separate and purify uranium, plutonium and neptunium. Converting the plant to thoria reprocessing required major process development work and equipment modifications. The operation and performance of the Plant during the 1970 thoria reprocessing campaign is discussed in this report. The discussion includes background information on the process and equipment, problems encountered, and changes recommended for future campaigns

  16. Plant operator performance evaluation based on cognitive process analysis experiment

    International Nuclear Information System (INIS)

    Ujita, H.; Fukuda, M.

    1990-01-01

    This paper reports on an experiment to clarify plant operators' cognitive processes that has been performed, to improve the man-machine interface which supports their diagnoses and decisions. The cognitive processes under abnormal conditions were evaluated by protocol analyses interviews, etc. in the experiment using a plant training simulator. A cognitive process model is represented by a stochastic network, based on Rasmussen's decision making model. Each node of the network corresponds to an element of the cognitive process, such as observation, interpretation, execution, etc. Some observations were obtained as follows, by comparison of Monte Carlo simulation results with the experiment results: A process to reconfirm the plant parameters after execution of a task and feedback paths from this process to the observation and the task definition of next task were observed. The feedback probability average and standard deviation should be determined for each incident type to explain correctly the individual differences in the cognitive processes. The tendency for the operator's cognitive level to change from skill-based to knowledge-based via rule-based behavior was observed during the feedback process

  17. Vil løyse global energikrise med thorium

    CERN Multimedia

    Aure, Gyri

    2007-01-01

    A professor from Bergen claims thorium can contribute to save the world from a global energy crisis. He wants Norway to construct the first accelerator driven reactor in the world powered by thorium. (5 pages)

  18. Determination of boron spectrophotometry in thorium sulfate

    International Nuclear Information System (INIS)

    Federgrun, L.; Abrao, A.

    1976-01-01

    A procedure for the determination of microquantities of boron in nuclear grade thorium sulfate is described. The method is based on the extraction of BF - 4 ion associated to monomethylthionine (MMT) in 1,2 - dichloroethane. The extraction of the colored BF - 4 -MMT complex does not allow the presence of sulfuric and phosphoric acids; other anions interfere seriously. This fact makes the dissolution of the thorium sulfate impracticable, since it is insoluble in both acids. On the other hand, the quantitative separation of thorium is mandatory, to avoid the precipitation of ThF 4 . To overcome this difficulty, the thorium sulfate is dissolved using a strong cationic ion exchanger, Th 4+ being totally retained into the resin. Boron is then analysed in the effluent. The procedure allows the determination of 0.2 to 10.0 microgramas of B, with a maximum error of 10%. Thorium sulfate samples with contents of 0.2 to 2.0μg B/gTh have being analysed [pt

  19. Moving towards sustainable thorium fuel cycles

    International Nuclear Information System (INIS)

    Hyland, B.; Hamilton, H.

    2011-01-01

    The CANDU reactor has an unsurpassed degree of fuel-cycle flexibility as a consequence of its fuel-channel design, excellent neutron economy, on-power refueling, and simple fuel bundle design. These features facilitate the introduction and full exploitation of thorium fuel cycles in CANDU reactors in an evolutionary fashion. Thoria (ThO 2 ) based fuel offers both fuel performance and safety advantages over urania (UO 2 ) based fuel, due its higher thermal conductivity which results in lower fuel-operating temperatures at similar linear element powers. Thoria fuel has demonstrated lower fission gas release than UO 2 under similar operating powers during test irradiations. In addition, thoria has a higher melting point than urania and is far less reactive in hypothetical accident scenarios owing to the fact that it has only one oxidation state. This paper examines one possible strategy for the introduction of thorium fuel cycles into CANDU reactors. In the short term, the initial fissile material would be provided in a heterogeneous bundle of low-enriched uranium and thorium. The medium term scenario uses homogeneous Pu/Th bundles in the CANDU reactor, further increasing the energy derived from the thorium. In the long term, the full energy potential from thorium would be realized through the recycle of the U-233 in the used fuel. With U-233 recycle in CANDU reactors, plutonium would then only be required to top up the fissile content to achieve the desired burnup. (author)

  20. Study of CO2 capture processes in power plants

    International Nuclear Information System (INIS)

    Amann, J.M.

    2007-12-01

    The aim of the present study is to assess and compare various processes aiming at recover CO 2 from power plants fed with natural gas (NGCC) and pulverized coal (PC). These processes are post-combustion CO 2 capture using chemical solvents, natural gas reforming for pre-combustion capture by methanol and oxy-fuel combustion with cryogenic recovery of CO 2 . These processes were evaluated using the process software Aspen PlusTM to give some clues for choosing the best option for each type of power plant. With regard to post-combustion, an aqueous solution based on a mixture of amines (N-methyldiethanolamine (MDEA) and triethylene tetramine (TETA)) was developed. Measurements of absorption were carried out between 298 and 333 K in a Lewis cell. CO 2 partial pressure at equilibrium, characteristic of the CO 2 solubility in the solvent, was determined up to 393 K. The solvent performances were compared with respect to more conventional solvents such as MDEA and monoethanolamine (MEA). For oxy-fuel combustion, a recovery process, based on a cryogenic separation of the components of the flue gas, was developed and applied to power plants. The study showed that O 2 purity acts on the CO 2 concentration in the flue gas and thus on the performances of the recovery process. The last option is natural gas reforming with CO 2 pre-combustion capture. Several configurations were assessed: air reforming and oxygen reforming, reforming pressure and dilution of the synthesis gas. The comparison of these various concepts suggests that, in the short and medium term, chemical absorption is the most interesting process for NGCC power plants. For CP power plants, oxy-combustion can be a very interesting option, as well as post-combustion capture by chemical solvents. (author)

  1. Maturation processes and structures of small secreted peptides in plants

    Directory of Open Access Journals (Sweden)

    Ryo eTabata

    2014-07-01

    Full Text Available In the past decade, small secreted peptides have proven to be essential for various aspects of plant growth and development, including the maintenance of certain stem cell populations. Most small secreted peptides identified in plants to date are recognised by membrane-localized receptor kinases, the largest family of receptor proteins in the plant genome. This peptide-receptor interaction is essential for initiating intracellular signalling cascades. Small secreted peptides often undergo post-translational modifications and proteolytic processing to generate the mature peptides. Recent studies suggest that, in contrast to the situation in mammals, the proteolytic processing of plant peptides involves a number of complex steps. Furthermore, NMR-based structural analysis demonstrated that post-translational modifications induce the conformational changes needed for full activity. In this mini review, we summarise recent advances in our understanding of how small secreted peptides are modified and processed into biologically active peptides and describe the mature structures of small secreted peptides in plants.

  2. Status and development of the thorium fuel cycle

    International Nuclear Information System (INIS)

    Yi Weijing; Wei Renjie

    2003-01-01

    A perspective view of the thorium fuel cycle is provided in this paper. The advantages and disadvantages of the thorium fuel cycle are given and the development of thorium fuel cycle in several types of reactors is introduced. The main difficulties in developing the thorium fuel cycle lie in the reprocessing and disposal of the waste and its economy, and the ways tried by foreign countries to solve the problems are presented in the paper

  3. Process plant alarm diagnosis using synthesised fault tree knowledge

    International Nuclear Information System (INIS)

    Trenchard, A.J.

    1990-01-01

    The development of computer based tools, to assist process plant operators in their task of fault/alarm diagnosis, has received much attention over the last twenty five years. More recently, with the emergence of Artificial Intelligence (AI) technology, the research activity in this subject area has heightened. As a result, there are a great variety of fault diagnosis methodologies, using many different approaches to represent the fault propagation behaviour of process plant. These range in complexity from steady state quantitative models to more abstract definitions of the relationships between process alarms. Unfortunately, very few of the techniques have been tried and tested on process plant and even fewer have been judged to be commercial successes. One of the outstanding problems still remains the time and effort required to understand and model the fault propagation behaviour of each considered process. This thesis describes the development of an experimental knowledge based system (KBS) to diagnose process plant faults, as indicated by process variable alarms. In an attempt to minimise the modelling effort, the KBS has been designed to infer diagnoses using a fault tree representation of the process behaviour, generated using an existing fault tree synthesis package (FAULTFINDER). The process is described to FAULTFINDER as a configuration of unit models, derived from a standard model library or by tailoring existing models. The resultant alarm diagnosis methodology appears to work well for hard (non-rectifying) faults, but is likely to be less robust when attempting to diagnose intermittent faults and transient behaviour. The synthesised fault trees were found to contain the bulk of the information required for the diagnostic task, however, this needed to be augmented with extra information in certain circumstances. (author)

  4. Chemical process measurements in PWR-type nuclear power plants

    International Nuclear Information System (INIS)

    Glaeser, E.

    1978-01-01

    In order to achieve high levels of availability of nuclear power plants equipped with pressurized water reactors, strict standards have to be applied to the purity of coolant and of other media. Chemical process measurements can meet these requirements only if programmes are established giving maximum information with minimum expenditure and if these programmes are realized with effective analytical methods. Analysis programmes known from literature are proved for their usefulness, and hints are given for establishing rational programmes. Analytical techniques are compared with each other taking into consideration both methods which have already been introduced into nuclear power plant practice and methods not yet generally used in practice, such as atomic absorption spectrophotometry, gas chromatography, etc. Finally, based on the state of the art of chemical process measurements in nuclear power plants, the trends of future development are pointed out. (author)

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

    International Nuclear Information System (INIS)

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

    1994-01-01

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

  6. Alpha spectrometry and secondary ion mass spectrometry of thorium

    International Nuclear Information System (INIS)

    Strisovska, Jana; Kuruc, Jozef; Galanda, Dusan; Matel, Lubomir; Velic, Dusan; Aranyosiova, Monika

    2009-01-01

    A sample of thorium content on steel discs was prepared by electrodeposition with a view to determining the natural thorium isotope. Thorium was determined by alpha spectrometry and by secondary ion mass spectrometry and the results of the two methods were compared

  7. A survey of thorium utilization in thermal power reactors

    International Nuclear Information System (INIS)

    Oosterkamp, W.J.

    1974-01-01

    The present status of thorium utilization in thermal reactors HTGR's, HWR's and LWR's has been reviewed. Physics considerations are made to obtain the optimum use of thorium. Existing information on reprocessing and refabrication is given together with the properties of thorium metal and thoria

  8. Advanced Purex process for the new French reprocessing plants

    International Nuclear Information System (INIS)

    Viala, M.; Ledermann, P.; Pradel, P.

    1993-01-01

    The paper describes the main process innovations of the new Cogema reprocessing plants of La Hague (UP3 and UP2 800). Major improvements of process like the use of rotary dissolvers and annular columns, and also entirely new processes like solvent distillation and plutonium oxidizing dissolution, yield an advanced Purex process. The results of these innovations are significant improvements for throughput, end-products purification performances and waste minimization. They contribute also to limit personnel exposure. The main results of the first three years of operation are described. (author). 3 refs., 5 figs

  9. Preparation of microcuries of 234-thorium

    International Nuclear Information System (INIS)

    Suner, A.; La Gamma de Batistoni, A.M.; Botbol, J.

    1974-11-01

    A procedure for the preparation of microcuries of 234 Th from hydrochloric acid solutions of uranium (VI) is described. A solution of uranyl chloride in radioactive equilibrium with 234 Th (older than 6 months) and having 232 Th as carrier, is percoled through a Dowex 50 Wx8 (H + ) resin bed, wherein is absorbed 85% of Th and some uranium, which is then desorbed with 10 N HCl. The thorium remains in the column and is extracted later with a 0,025 M SO 4 H 2 plus 1 M SO 4 (NH 4 ) 2 solution. The thorium solution is freed from sulfate by precipitation with ammonia, dissolving the precipitate with 10 N HCl, whose solution is treated with Dowex 2x8 resin. The ion exchanger absorbs the anionic impurities and the thorium obtained is of high chemical and radiochemical purity. (author)

  10. Maintenance of process instrumentation in nuclear power plants

    CERN Document Server

    Hashemian, H M

    2006-01-01

    Compiles 30 years of practical knowledge gained by the author and his staff in testing the I and C systems of nuclear power plants around the world. This book focuses on process temperature and pressure sensors and the verification of these sensors' calibration and response time.

  11. Radiosterilization process control in plants using electron accelerators

    International Nuclear Information System (INIS)

    Stuglik, Z.

    1997-01-01

    Electron beam parameters deciding the irradiation dose in radiosterilization plants should be continuously controlled during the process. Dosimetric procedure suitable to irradiated material and dose range should be chosen. The practical advice and directions in this subject have been done. 7 refs

  12. Simulation of Plant Physiological Process Using Fuzzy Variables

    Science.gov (United States)

    Daniel L. Schmoldt

    1991-01-01

    Qualitative modelling can help us understand and project effects of multiple stresses on trees. It is not practical to collect and correlate empirical data for all combinations of plant/environments and human/climate stresses, especially for mature trees in natural settings. Therefore, a mechanistic model was developed to describe ecophysiological processes. This model...

  13. Water-integrated scheduling of batch process plants

    NARCIS (Netherlands)

    Pulluru, Sai Jishna; Akkerman, Renzo

    2017-01-01

    Efficient water management is becoming increasingly important in production systems, but companies often do not have any concrete strategies to implement. While there are numerous technological options for improving water efficiency in process plants, there is a lack of effective decision support to

  14. Water-integrated scheduling of batch process plants

    NARCIS (Netherlands)

    Pulluru, Sai Jishna; Akkerman, Renzo

    2018-01-01

    Efficient water management is becoming increasingly important in production systems, but companies often do not have any concrete strategies to implement. While there are numerous technological options for improving water efficiency in process plants, there is a lack of effective decision support to

  15. Secondary cleanup of Idaho Chemical Processing Plant solvent

    International Nuclear Information System (INIS)

    Mailen, J.C.

    1985-01-01

    Solvent from the Idaho Chemical Processing Plant (ICPP) (operated by Westinghouse Idaho Nuclear Company, Inc.) has been tested to determine the ability of activated alumina to remove secondary degradation products - those degradation products which are not removed by scrubbing with sodium carbonate

  16. Yield analysis at a poultry processing plant in Harare, Zimbabwe ...

    African Journals Online (AJOL)

    This investigation was conducted to establish the yield of parts or organs of chickens brought for slaughter at a poultry processing plant in Harare. Results of the study will furnish management and other poultry farmers with information that will enable them to identify yield losses and sustainable ways of minimizing resultant ...

  17. Heat Integration and Renewable Energy in Meat Processing Plants

    OpenAIRE

    Colley, Tracey Anne

    2016-01-01

    This thesis aims to optimise energy efficiency at meat processing plants and minimise their carbon footprint, as a way of reducing operating costs and minimising the potential negative impacts of a carbon price on the red meat industry. In the context of the export meat industry, there is continual competition with the live export trade. Therefore, there is a risk that a carbon price could increase the live export trade over domestic processing of meat, thereby exporti...

  18. Three essential management processes of nuclear power plant operators

    International Nuclear Information System (INIS)

    Qi Tunfeng

    2010-01-01

    The paper takes the operation and management of Qinshan NPP Phase II as an example, focusing on the implementation of the essential process from the following three aspects the NPP production organization, training, examination and authorization for safety-related personnel, and financing budge management. A better understanding and implementation of the essential process will enable nuclear power plants to effectively control the nuclear safety from the most fundamental managerial level. (author)

  19. Core Design and Deployment Strategy of Heavy Water Cooled Sustainable Thorium Reactor

    Directory of Open Access Journals (Sweden)

    Naoyuki Takaki

    2012-08-01

    Full Text Available Our previous studies on water cooled thorium breeder reactor based on matured pressurized water reactor (PWR plant technology concluded that reduced moderated core by arranging fuel pins in a triangular tight lattice array and using heavy water as coolant is appropriate for achieving better breeding performance and higher burn-up simultaneously [1–6]. One optimum core that produces 3.5 GW thermal energy using Th-233U oxide fuel shows a breeding ratio of 1.07 and averaged burn-up of about 80 GWd/t with long cycle length of 1300 days. The moderator to fuel volume ratio is 0.6 and required enrichment of 233U for the fresh fuel is about 7%. The coolant reactivity coefficient is negative during all cycles despite it being a large scale breeder reactor. In order to introduce this sustainable thorium reactor, three-step deployment scenario, with intermediate transition phase between current light water reactor (LWR phase and future sustainer phase, is proposed. Both in transition phase and sustainer phase, almost the same core design can be applicable only by changing fissile materials mixed with thorium from plutonium to 233U with slight modification in the fuel assembly design. Assuming total capacity of 60 GWe in current LWR phase and reprocessing capacity of 800 ton/y with further extensions to 1600 ton/y, all LWRs will be replaced by heavy water cooled thorium reactors within about one century then thorium reactors will be kept operational owing to its potential to sustain fissile fuels while reprocessing all spent fuels until exhaustion of massive thorium resource.

  20. Southern complex: geology, geochemistry, mineralogy, and mineral chemistry of selected uranium- and thorium-rich granites

    International Nuclear Information System (INIS)

    Hoffman, M.A.

    1987-01-01

    Four major rock groups are defined in the Southern Complex: the Bell Creek Granite (BCG), the Clotted Granitoids (CGR), the Albite Granite (AGR), and the Migmatite Complex. Metatexites of the Migmatite Complex are the oldest rocks and include paleosome of a metasedimentary and metavolcanic protolith represented by Banded Iron Formation, Banded Amphibolite, and Banded Gneisses, and interlayered or crosscutting leucogranites. The CGR span the range from metatexite to diatexite and represent in-situ partial melting of metapelitic layers in the protolith during intrusion of the BCG. The BCG cuts the migmatites, is locally cut by the CGR, and was derived by partial melting of a dominantly metasedimentary protolith at some depth below the presently exposed migmatites during a regional tectonothermal event. The Albite Granite is a 2km diameter, muscovite-fluorite-columbite-bearing intrusive stock that cuts all other major units. The thorium history of the BCG is a function of the history of monazite. The thorium history of the CGR is also dominated by monazite but the thorium content of this unit cannot be entirely accounted for by original restite monazite. The uranium history of the BCG and CGR was dominated by magmatic differentiation and post magmatic, metamorphic and supergene redistributions and is largely independent of the thorium history. The thorium and uranium history of the AGR was dominated by magmatic/deuteric processes unlike the BCG and CGR

  1. Synthesis of manganese oxides and antimony silicates and their applications to take up Thorium-234

    International Nuclear Information System (INIS)

    Al-Attar, L.; Budeir, Y.

    2009-07-01

    Birnessite, a layered manganese oxide, antimonysilicate and their corresponding cation-exchange derivatives were tested for their ability to take up thorium using a batch-type method. Sorption experiments were performed in different concentrations of acid, and sodium, potassium and calcium nitrate solutions in order to evaluate the influence of cations likely to be present in waste effluents. The results were expressed in terms of distribution coefficients. Linear regressions of the logarithmic plots enabled the elucidation of exchange mechanisms. Variation in the magnitude and mechanism of thorium sorption on the exchangers was ascribed to structural differences and the exchange properties of the materials, as well as the aqueous chemistry of the actinide element. The work expanded to included investigation of thorium solution' pH in controlling the sorption process. In nitric acid solutions, H-antimonysilicate proved to be the best sorbent. The hydrated layer structure of birnessite allows for facile mobility of the interlayer cations with fast kinetics and little structural rearrangement, making it of great importance for intercalation and ion exchange uses in salt conditions. Potassium had the most, and calcium the least, effect on thorium selectivity by birnessites, when they are present as macro components. Conversely, calcium ions did greatly inhibit the sorption behaviour of the actinide on Ca-doped antimonysilicate. Studying the effect of thorium solution' pH reflected the microcrystal modifications of birnessites occurred during experiments. (authors)

  2. New Process Controls for the Hera Cryogenic Plant

    Science.gov (United States)

    Böckmann, T.; Clausen, M.; Gerke, Chr.; Prüß, K.; Schoeneburg, B.; Urbschat, P.

    2010-04-01

    The cryogenic plant built for the HERA accelerator at DESY in Hamburg (Germany) is now in operation for more than two decades. The commercial process control system for the cryogenic plant is in operation for the same time period. Ever since the operator stations, the control network and the CPU boards in the process controllers went through several upgrade stages. Only the centralized Input/Output system was kept unchanged. Many components have been running beyond the expected lifetime. The control system for one at the three parts of the cryogenic plant has been replaced recently by a distributed I/O system. The I/O nodes are connected to several Profibus-DP field busses. Profibus provides the infrastructure to attach intelligent sensors and actuators directly to the process controllers which run the open source process control software EPICS. This paper describes the modification process on all levels from cabling through I/O configuration, the process control software up to the operator displays.

  3. All part of the process[3D plant modelling

    Energy Technology Data Exchange (ETDEWEB)

    Snieckus, D.

    2002-12-01

    The second coming of EPIC contracts, a renewed emphasis on life-of-field costs for offshore developments, and the deepwater FPSO market's fast approaching construction boom are together demanding fresh thinking - and software systems - from 3D plant modelling and information specialists. Based on its own calculations, Intergraph's Process, Power and Offshore (PPO) division states that it holds down some 35-40% of the market for 3D plant modelling and information management in the offshore oil and gas industry. This article reviews their success, how they have to preserve their hard won share of the market, due to the changeable nature of that market, marked recently by the fundamental shifts in EPIC contract structure, life-of-field costs focuses, and, not least, the rise of FPSO-driven production concepts. Intergraph PPO's integrated product portfolio, which brings together plant design modelling systems and plant information management systems, was founded on its SmartPlant Foundation data warehouse hub. It has maintained its project data integrity o some of the largest and most complex offshore developments, including Phillips Petroleum's Bayu-Undan and Statoil Asgard fields. Some 70% of Intergraph PPO's clients have been contractors, and while the company aims to continue to build on the strength of these relationships, it also recognises that growing its client base of owner-operators will create some 'real synergies' in the process.

  4. Vulnerability analysis of process plants subject to domino effects

    International Nuclear Information System (INIS)

    Khakzad, Nima; Reniers, Genserik; Abbassi, Rouzbeh; Khan, Faisal

    2016-01-01

    In the context of domino effects, vulnerability analysis of chemical and process plants aims to identify and protect installations which are relatively more susceptible to damage and thus contribute more to the initiation or propagation of domino effects. In the present study, we have developed a methodology based on graph theory for domino vulnerability analysis of hazardous installations within process plants, where owning to the large number of installations or complex interdependencies, the application of sophisticated reasoning approaches such as Bayesian network is limited. We have taken advantage of a hypothetical chemical storage plant to develop the methodology and validated the results using a dynamic Bayesian network approach. The efficacy and out-performance of the developed methodology have been demonstrated via a real-life complex case study. - Highlights: • Graph theory is a reliable tool for vulnerability analysis of chemical plants as to domino effects. • All-closeness centrality score can be used to identify most vulnerable installations. • As for complex chemical plants, the methodology outperforms Bayesian network.

  5. Thorium converter (ThorCon) - a doable molten salt reactor

    International Nuclear Information System (INIS)

    Myneni, Ganapati

    2015-01-01

    ThorCon mass-producible nuclear power plants are being built to generate electricity cheaper than coal, at a scale to make a real improvement in world poverty and environment, now. ThorCon irradiated materials and fuel salt are designed to be replaced in four-year cycles with no impact on electricity generation. This flex-fuel plant and its replaceable reactor cans can operate with mixtures of thorium and uranium at multiple enrichments. Fuel salt can be NaF/BeF 2 or LiF/BeF 2 if available. ThorCon's design exceeds current nuclear power safety practice. The team calls for regulatory participation in rigorous testing of a full-scale prototype to develop licensing guidance

  6. Effects of feed process variables on Hanford Vitrification Plant performance

    International Nuclear Information System (INIS)

    Farnsworth, R.K.; Peterson, M.E.; Wagner, R.N.

    1987-01-01

    As a result of nuclear defense activities, high-level liquid radioactive wastes have been generated at the Hanford Site for over 40 yr. The Hanford Waste Vitrification Plant (HWVP) is being proposed to immobilize these wastes in a waste form suitable for disposal in a geologic repository. Prior to vitrification, the waste will undergo several conditioning steps before being fed to the melter. The effect of certain process variables on the resultant waste slurry properties must be known to assure processability of the waste slurry during feed preparation. Of particular interest are the rheological properties, which include the yield stress and apparent viscosity. Identification of the rheological properties of the slurry is required to adequately design the process equipment used for feed preparation (agitators, mixing tanks, concentrators, etc.). Knowledge of the slurry rheological properties is also necessary to establish processing conditions and operational limits for maximum plant efficiency and reliability. A multivariable study was performed on simulated HWVP feed to identify the feed process variables that have a significant impact on rheology during processing. Two process variables were evaluated in this study: (a) the amount of formic acid added to the feed and (b) the degree of shear encountered by the feed during processing. The feed was physically and rheologically characterized at various stages during feed processing

  7. Reprocessing in the thorium fuel cycle

    International Nuclear Information System (INIS)

    Merz, E.

    1984-01-01

    An overview of the authors personal view is presented on open questions in regard to still required research and development work for the thorium fuel cycle before its application in a technical-industrial scale may be tackled. For a better understanding, all stations of the back-end of the thorium fuel cycle are briefly illustrated and their special features discussed. They include storage and transportation measures, all steps of reprocessing, as well as the entire radioactive waste treatment. Knowledge gaps are, as far as they are obvious, identified and proposals put forward for additional worthwile investigations. (orig.) [de

  8. Determination of thorium 230Th in soils

    International Nuclear Information System (INIS)

    Alvarez, A.; Palomares, J.

    1988-01-01

    A method for the determination of 230 Th in environmental soils is described. Hydroxides formed, previous fusion with sodium peroxide are dissolved with HNO 3 8N. The thorium is coprecipitated with F 3 La and purified by anion exchange (AG 1x8 50-100 mesh). Thorium is electroplated onto a stainless steel disc, 230 Th is counted by alpha spectrometry and 234 Th used as a tracer by beta counting. The chemical yield for 1g of soil sample is 60-80%. Minimum detectable activities are about 2 mBq/g. (Author)

  9. Depth-Resolved Cathodoluminescence of Thorium Dioxide

    Science.gov (United States)

    2013-03-01

    plutonium-239 (239Pu)-based nuclear weapons. Thorium also results in less highly radioactive waste in comparison to the uranium fuels. Thorium is four...diameters (1/4 – 3/8”) (Mann & Thompson, 2010). The 99.99% ThO2 powder was placed into the ampoule with a basic mineralizer such as cesium fluoride...conversion ranging from 1 pA/V to 1 mA/V. The electrical noise is further reduced by cooling the PMT housing unit with liquid nitrogen as seen in

  10. Concept of a cognitive-numeric plant and process modelizer

    International Nuclear Information System (INIS)

    Vetterkind, D.

    1990-01-01

    To achieve automatic modeling of plant distrubances and failure limitation procedures, first the system's hardware and the present media (water, steam, coolant fluid) are formalized into fully computable matrices, called topographies. Secondly a microscopic cellular automation model, using lattice gases and state transition rules, is combined with a semi - microscopic cellular process model and with a macroscopic model, too. In doing this, at semi-microscopic level there are acting a cellular data compressor, a feature detection device and the Intelligent Physical Element's process dynamics. At macroscopic level the Walking Process Elements, a process evolving module, a test-and-manage device and abstracting process net are involved. Additionally, a diagnosis-coordinating and a counter measurements coordinating device are used. In order to automatically get process insights, object transformations, elementary process functions and associative methods are used. Developments of optoelectronic hardware language components are under consideration

  11. Process and apparatus for detecting presence of plant substances

    International Nuclear Information System (INIS)

    Kirby, J.A.

    1991-01-01

    This patent describes an apparatus and process for detecting the presence of plant substances in a particular environment. It comprises: measuring the background K40 gamma ray radiation level in a particular environment with a 1.46 MeV gamma ray counter system; measuring the amount of K40 gamma ray radiation emanating from a package containing a plant substance being passed through an environment with a counter; and generating an alarm signal when the total K40 gamma ray radiation reaches a predetermined level over and above the background level

  12. Radioactive waste processing method for a nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, Y; Kuriyama, O

    1976-06-04

    Object is to subject radioactive liquid waste in a nuclear power plant to reverse permeation process after which it is vaporized and concentrated thereby decreasing the quantity of foam to be used to achieve effective concentration of the liquid waste. Liquid waste containing a radioactive material produced from a nuclear power plant is first applied with pressure in excess of osmotic pressure by a reverse permeation device and is separated into clean water and concentrated liquid by semi-permeable membrane. Next, the thus reverse-permeated and concentrated waste is fed to an evaporator which control foaming by the foam and then further reconcentrated for purification of the liquid waste.

  13. Thermodynamic analysis applied to a food-processing plant

    Energy Technology Data Exchange (ETDEWEB)

    Ho, J C; Chandratilleke, T T

    1987-01-01

    Two production lines of a multi-product, food-processing plant are selected for energy auditing and analysis. Thermodynamic analysis showed that the first-law and second-law efficiencies are 81.5% and 26.1% for the instant-noodles line and 23.6% and 7.9% for the malt-beverage line. These efficiency values are dictated primarily by the major energy-consuming sub-processes of each production line. Improvements in both first-law and second-law efficiencies are possible for the plants if the use of steam for heating is replaced by gaseous or liquid fuels, the steam ejectors for creating vacuum are replaced by a mechanical pump, and employing the cooler surroundings to assist in the cooling process.

  14. Research on plant of metal fuel fabrication using casting process

    International Nuclear Information System (INIS)

    Senda, Yasuhide; Mori, Yukihide

    2003-12-01

    This document presents the plant concept of metal fuel fabrication system (38tHM/y) using casting process in electrolytic recycle, which based on recent studies of its equipment design and quality control system. And we estimate the cost of its construction and operation, including costs of maintenance, consumed hardware and management of waste. The content of this work is as follows. (1) Designing of fuel fabrication equipment: We make material flow diagrams of the fuel fabrication plant and rough designs of the injection casting furnace, demolder and inspection equipment. (2) Designing of resolution system of liquid waste, which comes from analytical process facility. Increased analytical items, we rearrange analytical process facility, estimate its chemicals and amount of waste. (3) Arrangement of equipments: We made a arrangement diagram of the metal fuel fabrication equipments in cells. (4) Estimation of cost data: We estimated cost to construct the facility and to operate it. (author)

  15. Comparison of the Environment, Health, And Safety Characteristics of Advanced Thorium- Uranium and Uranium-Plutonium Fuel Cycles

    Science.gov (United States)

    Ault, Timothy M.

    The environment, health, and safety properties of thorium-uranium-based (''thorium'') fuel cycles are estimated and compared to those of analogous uranium-plutonium-based (''uranium'') fuel cycle options. A structured assessment methodology for assessing and comparing fuel cycle is refined and applied to several reference fuel cycle options. Resource recovery as a measure of environmental sustainability for thorium is explored in depth in terms of resource availability, chemical processing requirements, and radiological impacts. A review of available experience and recent practices indicates that near-term thorium recovery will occur as a by-product of mining for other commodities, particularly titanium. The characterization of actively-mined global titanium, uranium, rare earth element, and iron deposits reveals that by-product thorium recovery would be sufficient to satisfy even the most intensive nuclear demand for thorium at least six times over. Chemical flowsheet analysis indicates that the consumption of strong acids and bases associated with thorium resource recovery is 3-4 times larger than for uranium recovery, with the comparison of other chemical types being less distinct. Radiologically, thorium recovery imparts about one order of magnitude larger of a collective occupational dose than uranium recovery. Moving to the entire fuel cycle, four fuel cycle options are compared: a limited-recycle (''modified-open'') uranium fuel cycle, a modified-open thorium fuel cycle, a full-recycle (''closed'') uranium fuel cycle, and a closed thorium fuel cycle. A combination of existing data and calculations using SCALE are used to develop material balances for the four fuel cycle options. The fuel cycle options are compared on the bases of resource sustainability, waste management (both low- and high-level waste, including used nuclear fuel), and occupational radiological impacts. At steady-state, occupational doses somewhat favor the closed thorium option while low

  16. Plant uprooting by flow as a fatigue mechanical process

    Science.gov (United States)

    Perona, Paolo; Edmaier, Katharina; Crouzy, Benoît

    2015-04-01

    In river corridors, plant uprooting by flow mostly occurs as a delayed process where flow erosion first causes root exposure until residual anchoring balances hydrodynamic forces on the part of the plant that is exposed to the stream. Because a given plant exposure time to the action of the stream is needed before uprooting occurs (time-to-uprooting), this uprooting mechanism has been denominated Type II, in contrast to Type I, which mostly affect early stage seedlings and is rather instantaneous. In this work, we propose a stochastic framework that describes a (deterministic) mechanical fatigue process perturbed by a (stochastic) process noise, where collapse occurs after a given exposure time. We test the model using the experimental data of Edmaier (2014) and Edmaier et al. (submitted), who investigated vegetation uprooting by flow in the limit of low plant stem-to-sediment size ratio by inducing parallel riverbed erosion within an experimental flume. We first identify the proper timescale and lengthscale for rescaling the model. Then, we show that it describes well all the empirical cumulative distribution functions (cdf) of time-to-uprooting obtained under constant riverbed erosion rate and assuming additive gaussian process noise. By this mean, we explore the level of determinism and stochasticity affecting the time-to-uprooting for Avena sativa in relation to root anchoring and flow drag forces. We eventually ascribe the overall dynamics of the Type II uprooting mechanism to the memory of the plant-soil system that is stored by root anchoring, and discuss related implications thereof. References Edmaier, K., Uprooting mechansims of juvenile vegetation by flow erosion, Ph.D. thesis, EPFL, 2014. Edmaier, K., Crouzy, B. and P. Perona. Experimental characterization of vegetation uprooting by flow. J. of Geophys. Res. - Biogeosci., submitted

  17. Exposure to airborne microorganisms and endotoxin in herb processing plants.

    Science.gov (United States)

    Dutkiewicz, J; Krysińska-Traczyk, E; Skórska, C; Sitkowska, J; Prazmo, Z; Golec, M

    2001-01-01

    Microbiological air sampling was performed in two herb processing plants located in eastern Poland. Air samples for determination of the levels of bacteria, fungi, dust and endotoxin were collected at 14 sites during cleaning, cutting, grinding, sieving, sorting and packing of 11 kinds of herbs (nettle, caraway, birch, celandine, marjoram, mint, peppermint, sage, St. John's wort, calamus, yarrow), used for production of medications, cosmetics and spices. It was found that processing of herbs was associated with a very high pollution of the air with bacteria, fungi, dust and endotoxin. The numbers of microorganisms (bacteria and fungi) in the air of herb processing plants ranged within 40.6-627.4 x 10(3) cfu/m3 (mean +/- S.D = 231.4 +/- 181.0 x 10(3) cfu/m3). The greatest concentrations were noted at the initial stages of production cycle, during cleaning, cutting and grinding of herbs. The numbers of airborne microorganisms were also significantly (pnettle, yarrow and mint. The values of the respirable fraction of airborne microflora in the examined facilities varied within a fairly wide range and were between 14.7-67.7%. The dominant microorganisms in the air of herb processing plants were mesophilic bacteria, among which endospore-forming bacilli (Bacillus spp.) and actinomycetes of the species Streptomyces albus were most numerous. Among Gram-negative bacteria, the most common was endotoxin-producing species Alcaligenes faecalis. Altogether, 37 species or genera of bacteria and 23 species or genera of fungi were identified in the air of herb processing plants, of these, 11 and 10 species or genera respectively were reported as having allergenic and/or immunotoxic properties. The concentrations of dust and bacterial endotoxin in the air of herb processing plants were large with extremely high levels at some sampling sites. The concentrations of airborne dust ranged within 3.2-946.0 mg/m3 (median 18.1 mg/m3), exceeding at 13 out of 14 sampling sites the Polish OEL

  18. Arbuscular mycorrhiza reduces phytoextraction of uranium, thorium and other elements from phosphate rock

    International Nuclear Information System (INIS)

    Roos, Per; Jakobsen, Iver

    2008-01-01

    Uptake of metals from uranium-rich phosphate rock was studied in Medicago truncatula plants grown in symbiosis with the arbuscular mycorrhizal fungus Glomus intraradices or in the absence of mycorrhizas. Shoot concentrations of uranium and thorium were lower in mycorrhizal than in non-mycorrhizal plants and root-to-shoot ratio of most metals was increased by mycorrhizas. This protective role of mycorrhizas was observed even at very high supplies of phosphate rock. In contrast, phosphorus uptake was similar at all levels of phosphate rock, suggesting that the P was unavailable to the plant-fungus uptake systems. The results support the role of arbuscular mycorrhiza as being an important component in phytostabilization of uranium. This is the first study to report on mycorrhizal effect and the uptake and root-to-shoot transfer of thorium from phosphate rock

  19. Arbuscular mycorrhiza reduces phytoextraction of uranium, thorium and other elements from phosphate rock

    Energy Technology Data Exchange (ETDEWEB)

    Roos, Per [Radiation Research Department, Riso National Laboratory, Technical University of Denmark, DK-4000 Roskilde (Denmark); Jakobsen, Iver [Biosystems Department, Riso National Laboratory, Technical University of Denmark, DK-4000 Roskilde (Denmark)], E-mail: iver.jakobsen@risoe.dk

    2008-05-15

    Uptake of metals from uranium-rich phosphate rock was studied in Medicago truncatula plants grown in symbiosis with the arbuscular mycorrhizal fungus Glomus intraradices or in the absence of mycorrhizas. Shoot concentrations of uranium and thorium were lower in mycorrhizal than in non-mycorrhizal plants and root-to-shoot ratio of most metals was increased by mycorrhizas. This protective role of mycorrhizas was observed even at very high supplies of phosphate rock. In contrast, phosphorus uptake was similar at all levels of phosphate rock, suggesting that the P was unavailable to the plant-fungus uptake systems. The results support the role of arbuscular mycorrhiza as being an important component in phytostabilization of uranium. This is the first study to report on mycorrhizal effect and the uptake and root-to-shoot transfer of thorium from phosphate rock.

  20. Thorium and uranium separation from Rare Earth complex minerals in Turkey

    International Nuclear Information System (INIS)

    Uzmen, R.

    2014-01-01

    Conclusion: • Thorium and uranium separation from a REEs solution is possible in by using simple traditional methods. • Main advantage of this method is to separate with high recovery yield uraniumand almost completely thorium which is an undesirable element due to its radioactive property in the different REEs group or individual REE. • Separation of thorium before any other step of REE’s group or individual element separation is crucial. • By using this flowsheet it would be possible to obtain uranium and other valuable elements (Zr, Ti, etc.) as coproducts of REEs. • Another important point, during REEs production, it is avoided to accumalate U and Th contaminated process wastes. • Thus, in the contrary, radioactive elements are refined and contained for safe storage.

  1. Process analysis in a THTR trial reprocessing plant

    International Nuclear Information System (INIS)

    Brodda, B.G.; Filss, P.; Kirchner, H.; Kroth, K.; Lammertz, H.; Schaedlich, W.; Brocke, W.; Buerger, K.; Halling, H.; Watzlawik, K.H.

    1979-01-01

    The demands on an analytical control system for a THTR trial reprocessing plant are specified. In a rather detailed example, a typical sampling, sample monitoring and measuring process is described. Analytical control is partly automated. Data acquisition and evaluation by computer are described for some important, largely automated processes. Sample management and recording of in-line and off-line data are carried out by a data processing system. Some important experiments on sample taking, sample transport and on special analysis are described. (RB) [de

  2. Competitive biosorption of thorium and uranium by Micrococcus luteus

    International Nuclear Information System (INIS)

    Nakajima, A.; Tsuruta, T.

    2004-01-01

    Eighteen species of bacteria were screened for abilities to adsorb thorium and uranium. High adsorption capacity was observed for thorium by Arthrobacter nicotianae and Micrococcus luteus, and for uranium by Arthrobacter nicotianae. The adsorption of both thorium and uranium by Micrococcus luteus cells was rapid, was affected by the solution pH, and obeyed the Langmuir adsorption isotherm for binary systems in a competitive manner taking the ionic charge of the metal ion into account. The thorium selectivity in the competitive adsorption is assumed to be caused by the faster adsorption and the slower desorption rates of thorium than those of uranium. (author)

  3. Empirical evaluation of the Process Overview Measure for assessing situation awareness in process plants.

    Science.gov (United States)

    Lau, Nathan; Jamieson, Greg A; Skraaning, Gyrd

    2016-03-01

    The Process Overview Measure is a query-based measure developed to assess operator situation awareness (SA) from monitoring process plants. A companion paper describes how the measure has been developed according to process plant properties and operator cognitive work. The Process Overview Measure demonstrated practicality, sensitivity, validity and reliability in two full-scope simulator experiments investigating dramatically different operational concepts. Practicality was assessed based on qualitative feedback of participants and researchers. The Process Overview Measure demonstrated sensitivity and validity by revealing significant effects of experimental manipulations that corroborated with other empirical results. The measure also demonstrated adequate inter-rater reliability and practicality for measuring SA in full-scope simulator settings based on data collected on process experts. Thus, full-scope simulator studies can employ the Process Overview Measure to reveal the impact of new control room technology and operational concepts on monitoring process plants. Practitioner Summary: The Process Overview Measure is a query-based measure that demonstrated practicality, sensitivity, validity and reliability for assessing operator situation awareness (SA) from monitoring process plants in representative settings.

  4. Determination of thorium and uranium particles in monazite airborne

    International Nuclear Information System (INIS)

    Cunha, K.M. de A.D. da

    1988-01-01

    The work is the determination of the Mass Median Aerodynamic Diameter of Airborne particles of Th and U, produced during the milling of monazite in Monozite Sand Plants. The air samples was collected using a Cascade Impactor from Delron DCI-6 with a flux of 12,5 1/min and cut-off diametes of 0,5, 1,0, 4,0, 8,0 and 16,0 μm. Each stage of the cascate impactor was analysed by measuring the X rays induced in collision with 2 MeV protons acellereted by a 4 MV Van de Graaff acceletor located at University Catolic, PUC, RJ. The MMAD found for Th and U was of 1,15 μm with a geometric standard desviation of 2,0. Take in acount that there are more thorium than uranium in the brazilian monazite, and the 232 Th 238 U are thr principal isotopes at the Th and U natural radioative decay series, we considered the mass and the activity distribution as equal. The mean concentration of Th (17,0 Bq/m 3 ) record in the air was 42% above 3/10 of international limit for concentration of oxides of thorium in the air, while the concentration of U remaind below 1/10 of the limit for concentration of U 3 O 8 in the air. (author) [pt

  5. Study on reprocessing of uranium-thorium fuel with solvent extraction for HTGR

    International Nuclear Information System (INIS)

    Jiao Rongzhou; He Peijun; Liu Bingren; Zhu Yongjun

    1992-08-01

    A single cycle process by solvent extraction with acid feed solution is suggested. The purpose is to reprocess uranium-thorium fuel elements which are of high burn-up and rich of 232 U from HTGR (high temperature gas cooled reactor). The extraction cascade tests have been completed. The recovery of uranium and thorium is greater than 99.6%. By this method, the requirement, under remote control to re-fabricate fuel elements, of decontamination factors for Cs, Sr, Zr-Nb and Ru has been reached

  6. Adsorption of thorium(IV) from aqueous solution by non-living biomass of mangrove endophytic fungus Fusarium sp. ZZF51

    International Nuclear Information System (INIS)

    Yang, S.K.; Tan, N.; Yan, X.M.; Chen, F.; Lin, Y.C.

    2013-01-01

    The adsorption of thorium(IV) from aqueous solution by mangrove endophytic fungus Fusarium sp. ZZF51 is studied by using a batch experiments. The parameters that affect the thorium(IV) sorption, such as solution pH, initial thorium(IV) concentration, contact time, and biomass dose, are discussed in detail. The maximum biosorption of thorium(IV) and the equilibrium sorption capacity are found to be 91 ± 1 % and 11.35 mg g -1 respectively at pH 3.0, contact time 20 min, initial thorium(IV) concentration 50 mg L -1 and non-living biomass dose 4.0 g L -1 . Kinetics data follow the pseudo-second-order model and equilibrium data agree with the Temkin isotherm model very well. FT-IR analysis indicates that hydroxyl and carbonyl groups play an important role in the biosorption process. (author)

  7. A study of uranium-thorium mixed lattices; Etude de reseaux mixtes uranium - thorium

    Energy Technology Data Exchange (ETDEWEB)

    Bacher, P; Eckert, R; Mazancourt, R de [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-07-01

    Some subcritical experiments have been carried out during the charging of the pile G1 by introducing thorium bars in a regular lattice into the pile. The spreading out of these experiments over a period of three months has permitted: a) work on a pile gradually increasing in size and b) measurements on comparable charges in so far that they have either the same number of bars of thorium, or the same concentration of thorium. From the measurements at constant charge and at constant concentration, it is possible by extrapolation to determine the critical charges and concentrations. The values obtained have showed that the material Laplacian of the lattice depends linearly on the thorium concentration and must cancel out for a concentration T = 8.8 {+-} 0.3 per cent by volume. These results have been found, to a very good approximation, by a simple calculation. (author) [French] Des experiences sous-critiques ont ete effectuees au cours du chargement de la pile G1 en introduisant des barres de thorium reparties suivant un reseau regulier dans la pile. L'etalement de ces experiences sur trois mois a permis d'operer sur une pile de plus en plus grosse et de faire un grand nombre de mesures sur des chargements comparables par le fait qu'ils avaient soit le meme nombre de barres de thorium, soit la meme concentration en thorium. A partir des mesures a chargement constant et a concentration constante, il a ete possible de determiner par extrapolation les chargements et concentrations critiques. Les valeurs obtenues ont montre que le laplacien matiere moyen du reseau dependait lineairement de la concentration en thorium, et devrait s'annuler pour une concentration T = 8,8 {+-} 0,3% en volume. Ces resultats ont ete retrouves avec une tres bonne approximation par un calcul elementaire. (auteur)

  8. Habitat Fragmentation Drives Plant Community Assembly Processes across Life Stages

    Science.gov (United States)

    Hu, Guang; Feeley, Kenneth J.; Yu, Mingjian

    2016-01-01

    Habitat fragmentation is one of the principal causes of biodiversity loss and hence understanding its impacts on community assembly and disassembly is an important topic in ecology. We studied the relationships between fragmentation and community assembly processes in the land-bridge island system of Thousand Island Lake in East China. We focused on the changes in species diversity and phylogenetic diversity that occurred between life stages of woody plants growing on these islands. The observed diversities were compared with the expected diversities from random null models to characterize assembly processes. Regression tree analysis was used to illustrate the relationships between island attributes and community assembly processes. We found that different assembly processes predominate in the seedlings-to-saplings life-stage transition (SS) vs. the saplings-to-trees transition (ST). Island area was the main attribute driving the assembly process in SS. In ST, island isolation was more important. Within a fragmented landscape, the factors driving community assembly processes were found to differ between life stage transitions. Environmental filtering had a strong effect on the seedlings-to-saplings life-stage transition. Habitat isolation and dispersal limitation influenced all plant life stages, but had a weaker effect on communities than area. These findings add to our understanding of the processes driving community assembly and species coexistence in the context of pervasive and widespread habitat loss and fragmentation. PMID:27427960

  9. Laboratory Enrichment of Radioactive Assemblages and Estimation of Thorium and Uranium Radioactivity in Fractions Separated from Placer Sands in Southeast Bangladesh

    International Nuclear Information System (INIS)

    Sasaki, Takayuki; Rajib, Mohammad; Akiyoshi, Masafumi; Kobayashi, Taishi; Takagi, Ikuji; Fujii, Toshiyuki; Zaman, Md. Mashrur

    2015-01-01

    The present study reports the likely first attempt of separating radioactive minerals for estimation of activity concentration in the beach placer sands of Bangladesh. Several sand samples from heavy mineral deposits located at the south-eastern coastal belt of Bangladesh were processed to physically upgrade their radioactivity concentrations using plant and laboratory equipment. Following some modified flow procedure, individual fractions were separated and investigated using gamma-ray spectrometry and powder-XRD analysis. The radioactivity measurements indicated contributions of the thorium and uranium radioactive series and of 40 K. The maximum values of 232 Th and 238 U, estimated from the radioactivity of 208 Tl and 234 Th in secular equilibrium, were found to be 152,000 and 63,300 Bq/kg, respectively. The fraction of the moderately conductive part in electric separation contained thorium predominantly, while that of the non-conductive part was found to be uranium rich. The present arrangement of the pilot plant cascade and the fine tuning of setting parameters were found to be effective and economic separation process of the radioactive minerals from placer sands in Bangladesh. Probable radiological impacts and extraction potentiality of such radioactive materials are also discussed

  10. Laboratory Enrichment of Radioactive Assemblages and Estimation of Thorium and Uranium Radioactivity in Fractions Separated from Placer Sands in Southeast Bangladesh

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Takayuki, E-mail: sasaki@nucleng.kyoto-u.ac.jp [Kyoto University, Department of Nuclear Engineering (Japan); Rajib, Mohammad [Bangladesh Atomic Energy Commission, Nuclear Minerals Unit, Atomic Energy Research Establishment (Bangladesh); Akiyoshi, Masafumi; Kobayashi, Taishi; Takagi, Ikuji [Kyoto University, Department of Nuclear Engineering (Japan); Fujii, Toshiyuki [Kyoto University, Research Reactor Institute (Japan); Zaman, Md. Mashrur [Bangladesh Atomic Energy Commission, Nuclear Minerals Unit, Atomic Energy Research Establishment (Bangladesh)

    2015-06-15

    The present study reports the likely first attempt of separating radioactive minerals for estimation of activity concentration in the beach placer sands of Bangladesh. Several sand samples from heavy mineral deposits located at the south-eastern coastal belt of Bangladesh were processed to physically upgrade their radioactivity concentrations using plant and laboratory equipment. Following some modified flow procedure, individual fractions were separated and investigated using gamma-ray spectrometry and powder-XRD analysis. The radioactivity measurements indicated contributions of the thorium and uranium radioactive series and of {sup 40}K. The maximum values of {sup 232}Th and {sup 238}U, estimated from the radioactivity of {sup 208}Tl and {sup 234}Th in secular equilibrium, were found to be 152,000 and 63,300 Bq/kg, respectively. The fraction of the moderately conductive part in electric separation contained thorium predominantly, while that of the non-conductive part was found to be uranium rich. The present arrangement of the pilot plant cascade and the fine tuning of setting parameters were found to be effective and economic separation process of the radioactive minerals from placer sands in Bangladesh. Probable radiological impacts and extraction potentiality of such radioactive materials are also discussed.

  11. The pilot plant for electron beam food processing

    International Nuclear Information System (INIS)

    Migdal, W.; Kosmal, W.; Malec-Czechowska, K.; Maciszewski, W.

    1992-01-01

    In the frames of the national programme on the application of irradiation for food preservation and hygienization an experimental plant for electron beam processing has been established in INCT. The pilot plant has been constructed inside an old fort what decreases significantly the cost of the investment. The pilot plants is equipped with a small research accelerator Pilot (10 MeV, 1 kW) and an industrial unit Elektronika (10 MeV, 10 kW). This allows both laboratory and full technological scale testing of the elaborated process to be conducted. The industrial unit is being equipped with e-/X conversion target, for high density products irradiation. On the basis of the research there were performed at different scientific institutions in Poland, health authorities have issued permissions for permanent treatment of spices, garlic, onions and temporary permissions for mushrooms, and potatoes. Dosimetric methods have been elaborated for the routine use at the plant. In the INCT laboratory methods for the control of e-/X treated food have been established. (author). 9 refs, 5 figs, 1 tab

  12. The pilot plant for electron beam food processing

    Science.gov (United States)

    Migdal, W.; Walis, L.; Chmielewski, A. G.

    1993-07-01

    In the frames of the national programme on the application of irradiation for food preservation and hygienization an experimental plant for electron beam processing has been established in INCT. The pilot plant has been constructed inside an old fort what decreases significantly the cost of the investment. The pilot plant is equipped with a small research accelerator Pilot (10 MeV, 1 kW) and an industrial unit Elektronika (10 MeV, 10 kW). This allows both laboratory and full technological scale testing of the elaborated process to be conducted. The industrial unit is being equipped with e-/X conversion target, for high density products irradiation. On the basis of the research there were performed at different scientific institutions in Poland, health authorities have issued permissions for permanent treatment of spices, garlic, onions and temporary permissions for mushrooms, and potatoes. Dosimetric methods have been elaborated for the routine use at the plant. In the INCT laboratory methods for the control of e-/X treated food have been established.

  13. Future perspective of thorium based nuclear fuels and thorium potential of Turkey

    International Nuclear Information System (INIS)

    Unak, T.; Yildirim, Y.

    2001-01-01

    Today's nuclear technology has principally been based on the use of fissile U-235 and Pu-239. he existence of thorium in the nature and its potential use in the nuclear technology were not unfortunately into account with a sufficient importance. The global distributions of thorium and uranium reserves indicate that in general some developed countries such as the USA, Canada, Australia, France have considerable uranium reserves, and contrarily only some developing countries such as Turkey, Brazil, India, Egypt have considerable thorium reserves. The studies carried out on the thorium during the last 50 years have clearly showed that the thorium based nuclear fuels have the potential easily use in most of reactor types actually operated with the classical uranium based nuclear fuels without any considerable modification. In the case of the use of thorium based nuclear fuels in future nuclear energy production systems, the serious problems such as the excess of Pu-239, the proliferation potential of nuclear weapons, and also the anxious of nuclear terrorism will probably be resolved, and sustainable nuclear energy production will be realized in the next new century. (authors)

  14. Future perspective of thorium based nuclear fuels and thorium potential of Turkey

    International Nuclear Information System (INIS)

    Unak, T.; Yildirim, Y.

    2000-01-01

    Today's nuclear technology has principally been based on the use of fissile U-235 and Pu-239. The existence of thorium in the nature and its potential use in the nuclear technology were not unfortunately into account with a sufficient importance. The global distributions of thorium and uranium reserves indicate that in general some developed countries such as the USA, Canada, Australia, France have considerable uranium reserves, and contrarily only some developing countries such as Turkey, Brazil, India, Egypt have considerable thorium reserves. The studies carried out on the thorium during the last 50 years have clearly showed that the thorium based nuclear fuels have the potential easily use in most of reactor types actually operated with the classical uranium based nuclear fuels without any considerable modification. In the case of the use of thorium based nuclear fuels in future nuclear energy production systems, the serious problems such as the excess of Pu-239, the proliferation potential of nuclear weapons, and also the anxious of nuclear terrorism will probably be resolved, and sustainable nuclear energy production will be realized in the next new century. (authors)

  15. Towards proliferation-resistant thorium fuels

    International Nuclear Information System (INIS)

    Alhaj, M. Yousif; Mohamed, Nader M.A.; Badawi, Alya; Abou-Gabal, Hanaa H.

    2017-01-01

    Thorium-plutonium mixture is proposed as alternative nuclear reactor fuel to incinerate the increasing stockpile plutonium. However, this fuel will produce an amount of uranium with about 90% 233U at applicable discharge burnups (60GWD/MTU). This research focuses on proposing an optimum non proliferative thorium fuel, by adding a small amount of 238U to reduce the attractiveness of the resultant uranium. Three types of additive which contain 238U were used: 4.98% enriched, natural and depleted uranium. We found that introducing uranium to the fresh thorium-plutonium fuel reduces its performance even if the uranium was enriched up to 5%. While uranium admixtures reduce the quality of the reprocessed uranium, it also increases the quality of the plutonium. However, this increase is very low compared to the reduced quality of uranium. We also found that using uranium as admixture for thorium-plutonium mixed fuel increases the critical mass of the extracted uranium by a factor of two when using only 1% admixture of uranium. The higher the percentage of uranium admixture the higher the critical mass of the reprocessed one.

  16. Utilization of thorium in PWR type reactors

    International Nuclear Information System (INIS)

    Correa, F.

    1977-01-01

    Uranium 235 consumption is comparatively evaluated with thorium cycle for a PWR type reactor. Modifications are only made in fuels components. U-235 consumption is pratically unchanged in both cycles. Some good results are promised to the mixed U-238/Th-232 fuel cycle in 1/1 proportion [pt

  17. Thorium cycle and molten salt reactors: field parameters and field constraints investigations toward 'thorium molten salt reactor' definition

    International Nuclear Information System (INIS)

    Mathieu, L.

    2005-09-01

    Producing nuclear energy in order to reduce the anthropic CO 2 emission requires major technological advances. Nuclear plants of 4. generation have to respond to several constraints, as safety improvements, fuel breeding and radioactive waste minimization. For this purpose, it seems promising to use Thorium Cycle in Molten Salt Reactors. Studies on this domain have already been carried out. However, the final concept suffered from serious issues and was discontinued. A new reflection on this topic is being led in order to find acceptable solutions, and to design the Thorium Molten Salt Reactor concept. A nuclear reactor is simulated by the coupling of a neutron transport code with a materials evolution code. This allows us to reproduce the reactor behavior and its evolution all along its operation. Thanks to this method, we have studied a large number of reactor configurations. We have evaluated their efficiency through a group of constraints they have to satisfy. This work leads us to a better understanding of many physical phenomena controlling the reactor behavior. As a consequence, several efficient configurations have been discovered, allowing the emergence of new points of view in the research of Molten Salt Reactors. (author)

  18. Saltstone processing startup at the Savannah River Plant

    International Nuclear Information System (INIS)

    Wilhite, E.L.; Langton, C.A.; Sturm, H.F.; Hooker, R.L.; Occhipinti, E.S.

    1988-01-01

    High-level nuclear wastes are stored in large underground tanks at the Savannah River Plant. Processing of this waste in preparation for ultimate disposal will begin in 1988. The waste will be processed to separate the high-level radioactive fraction from the low-level radioactive fraction. The separation will be made in existing waste tanks by a process combining precipitation, adsorption, and filtration. The high-level fraction will be vitrified into borosilicate glass in the Defense Waste Processing Facility (DWPF) for permanent disposal in a federal repository. The low-level fraction (decontaminated salt solution) will be mixed with a cementitious slag-flyash blend. The resulting wasteform, saltstone, will be disposed of onsite by emplacement in an engineered facility. Waste properties, disposal facility details, and wasteform characteristics are discussed. In particular, details of saltstone processing, focusing on experience obtained from facility startup, are presented

  19. Report of the study grou: Data Processing in Reprocessing Plants

    International Nuclear Information System (INIS)

    1976-08-01

    A study group to examine Data Processing in Spent Fuel Reprocessing Plants was created at the request of the Head of Productions and entrusted to the Director of the La Hague Centre. The groupe was made up of engineers working in different fields: piloting, architecture, building outfits, services etc. To begin with the group examined the solutions proposed by the La Hague Centre for the replacement of data processing units in service at the time but too old and unreliable to meet the safety rules laid down. Secondly, as a contribution towards France's heritage in the fuel reprocessing field, the group investigated systems and configurations for possible application to the equipment of future plants. The results of these studies were submitted in January 1974 [fr

  20. Maintenance of process instrumentation in nuclear power plants

    International Nuclear Information System (INIS)

    Hashemian, H.M.

    2006-01-01

    The resurgence of the nuclear power industry at a time when the nuclear plant I and C workforce is diminishing due to aging and retirements has been the motivation for writing this book. This book compiles 30 years of practical knowledge gained by the author and his staff in testing the I and C systems of nuclear power plants around the world. It focuses on process temperature and pressure sensors and the verification of these sensors' calibration and response time. In spite of great advances in electronics, computers, and measurement technologies, important process parameters such as temperature and pressure are still measured with conventional sensing techniques found in RTDs, thermocouples, and conventional pressure and differential pressure sensors. Furthermore, no improved technology providing comparable performance is currently on the horizon. Therefore, it is important to understand how these sensors function and the testing techniques for verifying their performance. This book is intended to help provide this understanding. (orig.)

  1. Job training planning and design for process plant operators

    Energy Technology Data Exchange (ETDEWEB)

    Wirstad, J.

    1983-01-01

    A method is presented by which process plant operators for nuclear power plants are trained in Sweden. It works by a top-down method of systems analysis which can be integrated into the analysis, specification, and design of the process automation system. The training methods can also be adapted to existing automation systems and operating schedules. The author's method is based on the principle that training programs should be based on job requirements, e.g. operator tasks in common, less frequent, and rare operating conditions. Procedures have been tested for the following steps: Job analysis, analysis of knowledge and experience required, analysis of operator training requirements, set-up and organisation of the training programme, achievement control, evaluation of the training programme.

  2. Job training planning and design for process plant operators

    International Nuclear Information System (INIS)

    Wirstad, J.

    1983-01-01

    A method is presented by which process plant operators for nuclear power plants are trained in Sweden. It works by a top-down method of systems analysis which can be integrated into the analysis, specification, and design of the process automation system. The training methods can also be adapted to existing automation systems and operating schedules. The author's method is based on the principle that training programs should be based on job requirements, e.g. operator tasks in common, less frequent, and rare operating conditions. Procedures have been tested for the following steps: Job analysis, analysis of knowledge and experience required, analysis of operator training requirements, set-up and organisation of the training programme, achievement control, evaluation of the training programme. (orig./HP) [de

  3. Process control of an HTGR fuel reprocessing cold pilot plant

    International Nuclear Information System (INIS)

    Rode, J.S.

    1976-10-01

    Development of engineering-scale systems for a large-scale HTGR fuel reprocessing demonstration facility is currently underway in a cold pilot plant. These systems include two fluidized-bed burners, which remove the graphite (carbon) matrix from the crushed HTGR fuel by high temperature (900 0 C) oxidation. The burners are controlled by a digital process controller with an all analog input/output interface which has been in use since March, 1976. The advantages of such a control system to a pilot plant operation can be summarized as follows: (1) Control loop functions and configurations can be changed easily; (2) control constants, alarm limits, output limits, and scaling constants can be changed easily; (3) calculation of data and/or interface with a computerized information retrieval system during operation are available; (4) diagnosis of process control problems is facilitated; and (5) control panel/room space is saved

  4. Integration of drinking water treatment plant process models and emulated process automation software

    NARCIS (Netherlands)

    Worm, G.I.M.

    2012-01-01

    The objective of this research is to limit the risks of fully automated operation of drinking water treatment plants and to improve their operation by using an integrated system of process models and emulated process automation software. This thesis contains the design of such an integrated system.

  5. Gas stripping and recirculation process in heavy water separation plant

    International Nuclear Information System (INIS)

    Nazzer, D.B.; Thayer, V.R.

    1976-01-01

    Hydrogen sulfide is stripped from hot effluent, in a heavy water separation plant of the dual temperature isotope separation type, by taking liquid effluent from the hot tower before passage through the humidifier, passing the liquid through one or more throttle devices to flash-off the H 2 S gas content, and feeding the gas into an absorption tower containing incoming feed water, for recycling of the gas through the process

  6. Safety implications of computerized process control in nuclear power plants

    International Nuclear Information System (INIS)

    1991-02-01

    Modern nuclear power plants are making increasing use of computerized process control because of the number of potential benefits that accrue. This practice not only applies to new plants but also to those in operation. Here, the replacement of both conventional process control systems and outdated computerized systems is seen to be of benefit. Whilst this contribution is obviously of great importance to the viability of nuclear electricity generation, it must be recognized that there are major safety concerns in taking this route. However, there is the potential for enhancing the safety of nuclear power plants if the full power of microcomputers and the associated electronics is applied correctly through well designed, engineered, installed and maintained systems. It is essential that areas where safety can be improved be identified and that the pitfalls are clearly marked so that they can be avoided. The deliberations of this Technical Committee Meeting are a step on the road to this goal of improved safety through computerized process control. This report also contains the papers presented at the technical committee meeting by participants. A separate abstract was prepared for each of these 15 presentations. Refs, figs and tabs

  7. Increasing operational efficiency in a radioactive waste processing plant - 16100

    International Nuclear Information System (INIS)

    Turner, T.W.; Watson, S.N.

    2009-01-01

    The solid waste plant at Harwell in Oxfordshire, contains a purpose built facility to input, assay, visually inspect and sort remote handled intermediate level radioactive waste (RHILW). The facility includes a suite of remote handling cells, known as the head-end cells (HEC), which waste must pass through in order to be repackaged. Some newly created waste from decommissioning works on site passes through the cells, but the vast majority of waste for processing is historical waste, stored in below ground tube stores. Existing containers are not suitable for long term storage, many are already badly corroded, so the waste must be efficiently processed and repackaged in order to achieve passive safety. The Harwell site is currently being decommissioned and the land is being restored. The site is being progressively de-licensed, and redeveloped as a business park, which can only be completed when all the nuclear liabilities have been removed. The recovery and processing of old waste in the solid waste plant is a key project linked to de-licensing of a section of the site. Increasing the operational efficiency of the waste processing plant could shorten the time needed to clear the site and has the potential to save money for the Nuclear Decommissioning Authority (NDA). The waste processing facility was constructed in the mid 1990's, and commissioned in 1999. Since operations began, the yearly throughput of the cells has increased significantly every year. To achieve targets set out in the lifetime plan (LTP) for the site, throughput must continue to increase. The operations department has measured the overall equipment effectiveness (OEE) of the process for the last few years, and has used continuous improvement techniques to decrease the average cycle time. Philosophies from operational management practices such as 'lean' and 'kaizen' have been employed successfully to drive out losses and increase plant efficiency. This paper will describe how the solid waste plant

  8. Future trends in power plant process computer techniques

    International Nuclear Information System (INIS)

    Dettloff, K.

    1975-01-01

    The development of new concepts of the process computer technique has advanced in great steps. The steps are in the three sections: hardware, software, application concept. New computers with a new periphery such as, e.g., colour layer equipment, have been developed in hardware. In software, a decisive step in the sector 'automation software' has been made. Through these components, a step forwards has also been made in the question of incorporating the process computer in the structure of the whole power plant control technique. (orig./LH) [de

  9. Prototype plant for nuclear process heat (PNP) - operation of the pilot plant for hydrogasification of coal

    International Nuclear Information System (INIS)

    Bruengel, N.; Dehms, G.; Fiedler, P.; Gerigk, H.P.; Ruddeck, W.; Schrader, L.; Schumacher, H.J.

    1988-04-01

    The Rheinische Braunkohlenwerke AG developed the process of hydrogasification of coal in a fluidized bed for generation of SNG. On basis of test results obtained in a semi-technical pilot plant of a through-put of 250 kg/h dried coal a large pilot plant was erected processing 10 t/h dried brown coal. This plant was on stream for about 14700 h, of which about 7800 h were with gasifier operation; during this time about 38000 t of dried brown coal of the Rhenish district were processed containing 4 to 25% of ash. At pressures of 60 to 120 bar and temperatures of 800 to 935 0 C carbon conversion rates up to 81 percent and methane amounts of 5000 m 3 (STP)/h were reached. The decisive parameter for methane generation was the hydrogen/coal-ratio. Even at high moisture contents, usually diminishing the methane yield from the coal essentially, by high hydrogen/coal-ratios high methane yields could be obtained. The gasifier itself caused no troubles during the total time operation. Difficulties with the original design of the residual char cooler could be overcome by change-over from water injection to liquid carbon dioxide. The design of the heat recovery system proved well. Alltogether so the size increasement of the gasifier from the semi-technical to the large pilot plant as well as the harmonization of gas generation and gas refining was proved. (orig.) With 20 refs., 20 tabs., 81 figs [de

  10. Coal conversion process by the United Power Plants of Westphalia

    Energy Technology Data Exchange (ETDEWEB)

    1974-08-01

    The coal conversion process used by the United Power Plants of Westphalia and its possible applications are described. In this process, the crushed and predried coal is degassed and partly gasified in a gas generator, during which time the sulfur present in the coal is converted into hydrogen sulfide, which together with the carbon dioxide is subsequently washed out and possibly utilized or marketed. The residual coke together with the ashes and tar is then sent to the melting chamber of the steam generator where the ashes are removed. After desulfurization, the purified gas is fed into an external circuit and/or to a gas turbine for electricity generation. The raw gas from the gas generator can be directly used as fuel in a conventional power plant. The calorific value of the purified gas varies from 3200 to 3500 kcal/cu m. The purified gas can be used as reducing agent, heating gas, as raw material for various chemical processes, or be conveyed via pipelines to remote areas for electricity generation. The conversion process has the advantages of increased economy of electricity generation with desulfurization, of additional gas generation, and, in long-term prospects, of the use of the waste heat from high-temperature nuclear reactors for this process.

  11. Plant process computer system upgrades at the KSG simulator centre

    International Nuclear Information System (INIS)

    2006-01-01

    The human-machine interface (HMI) of a modern plant process computer system (PPC) differs significantly from that of older systems. Along with HMI changes, there are often improvements to system functionality such as alarm display and printing functions and transient data analysis capabilities. Therefore, the upgrade or replacement of a PPC in the reference plant will typically require an upgrade of the simulator (see Section 6.5.1 for additional information). Several options are available for this type of project including stimulation of a replica system,or emulation, or simulation of PPC functionality within the simulation environment. To simulate or emulate a PCC, detailed knowledge of hardware and software functionality is required. This is typically vendor proprietary information, which leads to licensing and other complications. One of the added benefits of stimulating the PPC system is that the simulator can be used as a test bed for functional testing (i.e. verification and validation) of the system prior to installation in the reference plant. Some of this testing may include validation of the process curve and system diagram displays. Over the past few years several German NPPs decided to modernize their plant process computer (PPC) systems. After the NPPs had selected the desired system to meet their requirements the question arose how to modernize the PPC systems on the corresponding simulators. Six German NPPs selected the same PPC system from the same vendor and it was desired to perform integral tests of the HMI on the simulators. In this case the vendor offered a stimulated variant of their system and it therefore made sense to choose that implementation method for upgrade of the corresponding simulators. The first simulator PPC modernization project can be considered as a prototype project for the follow-on projects. In general, from the simulator project execution perspective the implementation of several stimulated PPC systems of the same type

  12. Packaging of radioactive sludges at the Saclay effluent processing plant

    International Nuclear Information System (INIS)

    Cerre, Pierre; Mestre, Emile; Bourdrez, Jean; Leconnetable, Jean

    1964-10-01

    The authors describe technical and technological aspects of the packaging workshop for radioactive sludges produced by processes of co-precipitation of Saclay effluents. This facility is an achievement of studies which aimed at improving working conditions for the plant staff. This workshop implements a process of solidification of filtered sludge by mixing with a hydraulic binding agent. After some generalities on the decontamination process applied to effluents produced by the Saclay research centre, the authors present and describe the adopted process, propose a physical description of the facility: building, chemical engineering equipment (filtration, packaging, and handling). They describe facility operation: introduction of a block into the cell, block filling, output of a packaged container. They briefly discuss the first results of facility exploitation [fr

  13. Low-level radioactive waste processing at nuclear power plants

    International Nuclear Information System (INIS)

    1992-12-01

    The Solid Radwaste Processing Source Book is presented as a supplement to the Liquid Radwaste Source Book released in 1990 and updated in 1991. The publication is the result of an industry-wide survey, and is intended as a resource for technical and managerial decisions involving of the processing of solid radioactive waste including ''wet'' and ''dry'' active waste as found at both Pressurized and Boiling Water Reactor sites. In addition to information on processes, vendors, volumes, and in-plant management activities, technology under consideration for future use and computer applications are listed. Together with key personnel and contact information contained in the Liquid Source Books, the collected data will be of great use when seeking specific, unbiased experience on which to base decisions related to so processing, disposal policy, or potential economic and regulatory impact

  14. Plant life management processes and practices for heavy water reactors

    International Nuclear Information System (INIS)

    Kang, K.-S.; Cleveland, J.; Clark, C.R.

    2006-01-01

    responsibility for achievement of specific SSC lifetime. This paper discusses an overview of PLiM programs and considerations. This includes key objectives of such programs, regulatory considerations, asset management perspectives, integration of methodologies into current programs, organizational and technology infrastructure considerations, importance of effective plant data management and finally, benefits and costs. This paper is summary of the IAEA technical documents on 'Guidelines on Plant Life Management Processes and Practices for Heavy Water Reactors'. (author)

  15. Model-based reasoning and the control of process plants

    International Nuclear Information System (INIS)

    Vaelisuo, Heikki

    1993-02-01

    In addition to feedback control, safe and economic operation of industrial process plants requires discrete-event type logic control like for example automatic control sequences, interlocks, etc. A lot of complex routine reasoning is involved in the design and verification and validation (VandV) of such automatics. Similar reasoning tasks are encountered during plant operation in action planning and fault diagnosis. The low-level part of the required problem solving is so straightforward that it could be accomplished by a computer if only there were plant models which allow versatile mechanised reasoning. Such plant models and corresponding inference algorithms are the main subject of this report. Deep knowledge and qualitative modelling play an essential role in this work. Deep knowledge refers to mechanised reasoning based on the first principles of the phenomena in the problem domain. Qualitative modelling refers to knowledge representation formalism and related reasoning methods which allow solving problems on an abstraction level higher than for example traditional simulation and optimisation. Prolog is a commonly used platform for artificial intelligence (Al) applications. Constraint logic languages like CLP(R) and Prolog-III extend the scope of logic programming to numeric problem solving. In addition they allow a programming style which often reduces the computational complexity significantly. An approach to model-based reasoning implemented in constraint logic programming language CLP(R) is presented. The approach is based on some of the principles of QSIM, an algorithm for qualitative simulation. It is discussed how model-based reasoning can be applied in the design and VandV of plant automatics and in action planning during plant operation. A prototype tool called ISIR is discussed and some initial results obtained during the development of the tool are presented. The results presented originate from preliminary test results of the prototype obtained

  16. Thorium as an energy source. Opportunities for Norway; Thorium som energikilde - Muligheter for Norge

    Energy Technology Data Exchange (ETDEWEB)

    2008-02-15

    Final Recommendations of the Thorium Report Committee: 1) No technology should be idolized or demonized. All carbon-dioxide (Co2) emission-free energy production technologies should be considered. The potential contribution of nuclear energy to a sustainable energy future should be recognized. 2) An investigation into the resources in the Fen Complex and other sites in Norway should be performed. It is essential to assess whether thorium in Norwegian rocks can be defined as an economical asset for the benefit of future generations. Furthermore, the application of new technologies for the extraction of thorium from the available mineral sources should be studied. 3) Testing of thorium fuel in the Halden Reactor should be encouraged, taking benefit of the well recognized nuclear fuel competence in Halden. 4) Norway should strengthen its participation in international collaborations by joining the EURATOM fission program and the GIF program on Generation IV reactors suitable for the use of thorium. 5) The development of an Accelerator Driven System (ADS) using thorium is not within the capability of Norway working alone. Joining the European effort in this field should be considered. Norwegian research groups should be encouraged to participate in relevant international projects, although these are currently focused on waste management. 6) Norway should bring its competence in waste management up to an international standard and collaboration with Sweden and Finland could be beneficial. 7) Norway should bring its competence with respect to dose assessment related to the thorium cycle up to an international standard. 8) Since the proliferation resistance of uranium-233 depends on the reactor and reprocessing technologies, this aspect will be of key concern should any thorium reactor be built in Norway. 9) Any new nuclear activities in Norway, e.g. thorium fuel cycles, would need strong international pooling of human resources, and in the case of thorium, a strong long

  17. Concept of a HTR modular plant for generation of process heat in a chemical plant

    International Nuclear Information System (INIS)

    1991-07-01

    This final report summarizes the results of a preliminary study on behalf of Buna AG and Leunawerke AG. With regard to the individual situations the study investigated the conditions for modular HTR-2 reactors to cover on-site process heat and electric power demands. HTR-2 reactor erection and operation were analyzed for their economic efficiency compared with fossil-fuel power plants. Considering the prospective product lines, the technical and economic conditions were developed in close cooperation with Buna AG and Leunawerke AG. The study focused on the technical integration of modular HTR reactors into plants with regard to safety concepts, on planning, acceptance and erection concepts which largely exclude uncalculable scheduling and financial risks, and on comparative economic analyses with regard to fossil-fuel power plants. (orig.) [de

  18. STUDY OF PLANT-WIDE CONTROL IMPLEMENTATION IN PRODUCTION PROCESS OF GEOTHERMAL POWER PLANT

    Directory of Open Access Journals (Sweden)

    KATHERIN INDRIAWATI

    2017-02-01

    Full Text Available The design of plant-wide control system to optimize electricity production in geothermal power plant is proposed in this research. The objective is to overcome the deficiency due to changes in the characteristics of production well and fluctuation in electricity demand load. The proposed plant-wide control system has two main tasks; to maintain production process at optimum value and to increase efficiency. The pressure in separator and condenser is maintained at the respective set points under electrical load fluctuations in order to ensure optimum efficiency. The control system also reduce the usage of auxialiary electrical power and increase efficiency. The task was performed by controlling inlet cooling water temperatures to the condenser. It was concluded that the proposed control structure was able to increase efficiency and maintain production.

  19. Development of an experimental approach to study coupled soil-plant-atmosphere processes using plant analogs

    Science.gov (United States)

    Trautz, Andrew C.; Illangasekare, Tissa H.; Rodriguez-Iturbe, Ignacio; Heck, Katharina; Helmig, Rainer

    2017-04-01

    The atmosphere, soils, and vegetation near the land-atmosphere interface are in a state of continuous dynamic interaction via a myriad of complex interrelated feedback processes which collectively, remain poorly understood. Studying the fundamental nature and dynamics of such processes in atmospheric, ecological, and/or hydrological contexts in the field setting presents many challenges; current experimental approaches are an important factor given a general lack of control and high measurement uncertainty. In an effort to address these issues and reduce overall complexity, new experimental design considerations (two-dimensional intermediate-scale coupled wind tunnel-synthetic aquifer testing using synthetic plants) for studying soil-plant-atmosphere continuum soil moisture dynamics are introduced and tested in this study. Validation of these experimental considerations, particularly the adoption of synthetic plants, is required prior to their application in future research. A comparison of three experiments with bare soil surfaces or transplanted with a Stargazer lily/limestone block was used to evaluate the feasibility of the proposed approaches. Results demonstrate that coupled wind tunnel-porous media experimentation, used to simulate field conditions, reduces complexity, and enhances control while allowing fine spatial-temporal resolution measurements to be made using state-of-the-art technologies. Synthetic plants further help reduce system complexity (e.g., airflow) while preserving the basic hydrodynamic functions of plants (e.g., water uptake and transpiration). The trends and distributions of key measured atmospheric and subsurface spatial and temporal variables (e.g., soil moisture, relative humidity, temperature, air velocity) were comparable, showing that synthetic plants can be used as simple, idealized, nonbiological analogs for living vegetation in fundamental hydrodynamic studies.

  20. Prospective thorium fuels for future nuclear energy generation

    International Nuclear Information System (INIS)

    Lainetti, Paulo E.O.

    2017-01-01

    In the beginning of the Nuclear Era, many countries were interested on thorium, particularly during the 1950 1970 periods. Nevertheless, since its discovery almost two centuries ago, the use of thorium has been restricted to gas mantles employed in gas lighting. The future world energy needs will increase and, even if we assumed a conservative contribution of nuclear generation, it will be occur a significant increasing in the uranium prices, taking into account that uranium, as used in the present thermal reactors, is a finite resource. Nowadays approximately the worldwide yearly requirement of uranium for about 435 nuclear reactors in operation is 65,000 metric t. Therefore, alternative solutions for future must be developed. Thorium is nearly three times more abundant than uranium in The Earth's crust. Despite thorium is not a fissile material, 232 Th can be converted to 233 U (fissile) more efficiently than 238 U to 239 Pu. Besides this, thorium is an environment alternative energy source and also inherently resistant to proliferation.. Many countries had initiated research on thorium in the past, Nevertheless, the interest evanesced due new uranium resources discoveries and availability of enriched uranium at low prices from obsolete weapons. Some papers evaluate the thorium resources in Brazil over 1.200.000 metric t. Then, the thorium alternative must be seriously considered in Brazil for strategic reasons. A brief history of thorium and its utilization are presented, besides a very short discussion about prospective thorium nuclear fuels for the next generation of nuclear reactors. (author)

  1. Thorium and its future importance for nuclear energy generation

    International Nuclear Information System (INIS)

    Lainetti, Paulo E.O.

    2015-01-01

    Thorium was discovered in 1828 by the Swedish chemist Jons J. Berzelius. Despite some advantages over uranium for use in nuclear reactors, its main use, in the almost two centuries since its discovery, the use of thorium was restricted to use for gas mantles, especially in the early twentieth century. In the beginning of the Nuclear Era, many countries had interested on thorium, particularly during the 1950-1970 period. There are about 435 nuclear reactors in the world nowadays. They need more than 65.000 tons of uranium yearly. The future world energy needs will increase and, even if we assumed a conservative contribution of nuclear generation, it will be occur a significant increasing in the uranium prices, taking into account that uranium, as used in the present thermal reactors, is a finite resource. Thorium is nearly three times more abundant than uranium in the Earth's crust. Despite thorium is not a fissile material, 232 Th can be converted to 233 U (fissile) more efficiently than 238 U to 239 Pu. Besides this, since it is possible to convert thorium waste into nonradioactive elements, thorium is an environment-friendly alternative energy source. Thorium fuel cycle is also inherently resistant to proliferation. Some papers evaluate the thorium resources in Brazil over 1.200.000 metric t. Then, the thorium alternative must be seriously considered in Brazil for strategic reasons. In this paper a brief history of thorium is presented, besides a review of the world thorium utilization and a discussion about advantages and restrictions of thorium use. (author)

  2. Safety and Regulatory Issues of the Thorium Fuel Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Ade, Brian [ORNL; Worrall, Andrew [ORNL; Powers, Jeffrey [ORNL; Bowman, Steve [ORNL; Flanagan, George [ORNL; Gehin, Jess [ORNL

    2014-02-01

    Thorium has been widely considered an alternative to uranium fuel because of its relatively large natural abundance and its ability to breed fissile fuel (233U) from natural thorium (232Th). Possible scenarios for using thorium in the nuclear fuel cycle include use in different nuclear reactor types (light water, high temperature gas cooled, fast spectrum sodium, molten salt, etc.), advanced accelerator-driven systems, or even fission-fusion hybrid systems. The most likely near-term application of thorium in the United States is in currently operating light water reactors (LWRs). This use is primarily based on concepts that mix thorium with uranium (UO2 + ThO2), add fertile thorium (ThO2) fuel pins to LWR fuel assemblies, or use mixed plutonium and thorium (PuO2 + ThO2) fuel assemblies. The addition of thorium to currently operating LWRs would result in a number of different phenomenological impacts on the nuclear fuel. Thorium and its irradiation products have nuclear characteristics that are different from those of uranium. In addition, ThO2, alone or mixed with UO2 fuel, leads to different chemical and physical properties of the fuel. These aspects are key to reactor safety-related issues. The primary objectives of this report are to summarize historical, current, and proposed uses of thorium in nuclear reactors; provide some important properties of thorium fuel; perform qualitative and quantitative evaluations of both in-reactor and out-of-reactor safety issues and requirements specific to a thorium-based fuel cycle for current LWR reactor designs; and identify key knowledge gaps and technical issues that need to be addressed for the licensing of thorium LWR fuel in the United States.

  3. Sustained qualification process for full scope nuclear power plant simulators

    International Nuclear Information System (INIS)

    Pirson, J.; Stubbe, E.; Vanhoenacker, L.

    1994-01-01

    In the past decade, simulator training for all nuclear power plant operators has evolved into a vital requirement. To assure a correct training, the simulator qualification process is an important issue not only for the initial validation but also following major simulator updates, which are necessary during the lifetime of the simulator. In order to avoid degradation of the simulator validated software, the modifications have to be introduced according to a rigorous methodology and a practical requalification process has to be applied. Such methodology has to be enforced at every phase of the simulator construction or updating process from plant data package constitution, over simulator software development to simulator response qualification. The initial qualification and requalification process is based on the 3 levels identified by the ANSI/ANS 3-5 standard for steady-state, operational transients and accident conditions. For the initial certification of the full scope simulators in Belgium, a practical qualification methodology has been applied, which has been adapted into a set of non regression tests for the requalification after major simulator updates. (orig.) (4 refs., 3 figs.)

  4. NEURO-FUZZY MODELLING OF BLENDING PROCESS IN CEMENT PLANT

    Directory of Open Access Journals (Sweden)

    Dauda Olarotimi Araromi

    2015-11-01

    Full Text Available The profitability of a cement plant depends largely on the efficient operation of the blending stage, therefore, there is a need to control the process at the blending stage in order to maintain the chemical composition of the raw mix near or at the desired value with minimum variance despite variation in the raw material composition. In this work, neuro-fuzzy model is developed for a dynamic behaviour of the system to predict the total carbonate content in the raw mix at different clay feed rates. The data used for parameter estimation and model validation was obtained from one of the cement plants in Nigeria. The data was pre-processed to remove outliers and filtered using smoothening technique in order to reveal its dynamic nature. Autoregressive exogenous (ARX model was developed for comparison purpose. ARX model gave high root mean square error (RMSE of 5.408 and 4.0199 for training and validation respectively. Poor fit resulting from ARX model is an indication of nonlinear nature of the process. However, both visual and statistical analyses on neuro-fuzzy (ANFIS model gave a far better result. RMSE of training and validation are 0.28167 and 0.7436 respectively, and the sum of square error (SSE and R-square are 39.6692 and 0.9969 respectively. All these are an indication of good performance of ANFIS model. This model can be used for control design of the process.

  5. Remote sampling of process fluids in radiochemical plants

    International Nuclear Information System (INIS)

    Sengar, P.B.; Bhattacharya, R.; Ozarde, P. D.; Rana, D.S.

    1990-01-01

    Sampling of process fluids, continuous or periodic, is an essential requirement in any chemical process plant, so as to keep a control on process variables. In a radiochemical plant the task of taking and conveying the samples is a very tricky affair. This is due to the fact that neither the vessels/equipment containing radioactive effluents can be approached for manual sampling nor sampled fluids can be handled directly. The problems become more accute with higher levels of radioactivity. As such, inovative systems have to be devised to obtain and handle the raioactive samples employing remote operations. The remote sampling system developed in this Division has some of the unique features such as taking only requisite amount of samples in microlitre range, practically maintenance free design, avoidence of excess radioactive fluids coming out of process systems, etc. The paper describes in detail the design of remote sampling system and compares the same with existing systems. The design efforts are towards simplicity in operation, obtaining homogenised representative samples and highly economical on man-rem expenditure. The performance of a prototype system has also been evaluated. (author). 3 refs

  6. Iodine-129 in aquatic organisms near nuclear fuels processing plants

    International Nuclear Information System (INIS)

    Watson, D.G.

    1975-04-01

    Concentrations of 129 I in two aquatic habitats near nuclear fuel processing plants were highest in algae and crustaceans. These two forms may be useful in future monitoring of 129 I. There is some indication of an increase in atom ratios and specific activity in aquatic organisms over that in water and sediments. Additional measurements should be made to verify this conclusion. Efforts should continue to measure the possible long term build-up of 129 I in aquatic environments receiving effluents from fuels reprocessing plants. Even at very low rates of release to the environment, the long physical half-life of 129 I creates the potential for build-up of this nuclide to significant levels. (U.S.)

  7. Hanford Waste Vitrification Plant - the project and process systems

    International Nuclear Information System (INIS)

    Swenson, L.D.; Miller, W.C.; Smith, R.A.

    1990-01-01

    The Hanford Waste Vitrification Plant (HWVP) project is scheduled to start construction on the Hanford reservation in southeastern Washington State in 1991. The project will immobilize the liquid high-level defense waste stored there. The HWVP represents the third phase of the U.S. Department of Energy (DOE) activities that are focused on the permanent disposal of high-level radioactive waste, building on the experience of Defense Waste Processing Facility (DWPF) at the Savannah River site, South Carolina, and of the West Valley Demonstration Plant (WVDP), New York. This sequential approach to disposal of the country's commercial and defense high-level radioactive waste allows HWVP to make extensive use of lessons learned from the experience of its predecessors, using mature designs from the earlier facilities to achieve economies in design and construction costs while enhancing operational effectiveness

  8. Flow modelling of plant processes for fault diagnosis

    International Nuclear Information System (INIS)

    Praetorius, N.; Duncan, K.D.

    1989-01-01

    Flow and its interruption or degradation is seen by many people in industry to be the essential problem in fault diagnonsis. It is this observation which has motivated the representation of a complex simulation of a process plant presented here. The display system we have developed represents the mass and energy flow functions of the plant and the relationship between such flow functions. In this report we shall mainly discuss how such representation seems to provide opportunities to design alarm systems as an integral part of the flow function representation itself and to solve two of the most intricate problems in diagnosis, namely the problem of symptom referral and the problem of confuseable faults. (author)

  9. Biogeochemical aspects of the behavior of uranium and thorium in the environment

    International Nuclear Information System (INIS)

    Faust, R.A.; Bondietti, E.A.

    1976-09-01

    This bibliography contains 383 references on the environmental behavior of uranium and thorium. Most of the documents deal with the geochemical movement in soils and aquatic systems while biological aspects such as accumulations in plants and animals, transfer parameters between ecosystem components, and food chain dynamics are less extensively documented. The references are arranged by subject categories with first authors appearing alphabetically in each category. Indexes are provided for author, geographic location, keywords, taxons, permuted title and publication description

  10. A process to remove ammonia from PUREX plant effluents

    International Nuclear Information System (INIS)

    Moore, J.D.

    1990-01-01

    Zirconium-clad nuclear fuel from the Hanford N-Reactor is reprocessed in the PUREX (Plutonium Uranium Extraction) Plant operated by the Westinghouse Hanford Comapny. Before dissolution, cladding is chemically removed from the fuel elements with a solution of ammonium fluoride-ammonium nitrate (AFAN). a solution batch with an ammonia equivalent of about 1,100 kg is added to each fuel batch of 10 metric tons. This paper reports on this decladding process, know as the 'Zirflex' process which produces waste streams containing ammonia and ammonium slats. Waste stream treatment, includes ammonia scrubbing, scrub solution evaporation, residual solids dissolution, and chemical neutralization. These processes produce secondary liquid and gaseous waste streams containing varying concentrations of ammonia and low-level concentrations of radionuclides. Until legislative restrictions were imposed in 1987, these secondary streams were released to the soil in a liquid disposal 'crib' and to the atmosphere

  11. Designing new nuclear chemical processing plants for safeguards accountability

    International Nuclear Information System (INIS)

    Sprouse, K.M.

    1987-01-01

    New nuclear chemical processing plants will be required to develop material accountability control limits from measurement error propagation analysis rather than historical inventory difference data as performed in the past. In order for measurement error propagation methods to be viable alternatives, process designers must ensure that two nondimensional accountability parameters are maintained below 0.1. These parameters are ratios between the material holdup increase and the variance in inventory difference measurement uncertainty. Measurement uncertainty data for use in error propagation analysis is generally available in the open literature or readily derived from instrument calibration data. However, nuclear material holdup data has not been adequately developed for use in the material accountability design process. Long duration development testing on isolated unit operations is required to generate this necessary information

  12. Recovery of thorium and rare earths by their peroxides precipitation from a residue produced in the thorium purification facility

    International Nuclear Information System (INIS)

    Freitas, Antonio Alves de

    2008-01-01

    As consequence of the operation of a Thorium purification facility, for pure Thorium Nitrate production, the IPEN (Instituto de Pesquisas Energeticas e Nucleares) has stored away a solid residue called RETOTER (REsiduo de TOrio e TErras Raras). The RETOTER is rich in Rare-Earth Elements and significant amount of Thorium-232 and minor amount of Uranium. Furthermore it contains several radionuclides from the natural decay series. Significant radioactivity contribution is generated by the Thorium descendent, mainly the Radium-228(T 1/2 =5.7y), known as meso thorium and Thorium-228(T 1/2 1.90y). An important thorium daughter is the Lead-208, a stable isotope present with an expressive quantity. After the enclosure of the operation of the Thorium purification facility, many researches have been developed for the establishment of methodologies for recovery of Thorium, Rare-Earth Elements and Lead-208 from the RETOTER. This work presents a method for RETOTER decontamination, separating and bordering upon some radioactive isotopes. The residue was digested with nitric acid and the Radium-228 was separated by the Barium Sulphate co-precipitation procedure. Finally, the Thorium was separated by the peroxide precipitation and the Rare-Earth Elements were also recovered by the Rare-Earth peroxide precipitation in the filtrate solution.(author)

  13. A study of pulse columns for thorium fuel reprocessing

    International Nuclear Information System (INIS)

    Fumoto, H.

    1982-03-01

    Two 5 m pulse columns with the same cartridge geometries are installed to investigate the performance. The characteristic differences of the aqueous continous and the organic continuous columns were investigated experimentally. A ternary system of 30% TBP in dodecane-acetic acid-water was adopted for the mass-transfer study. It was concluded that the overall mass-transfer coefficient was independent of whether the mass-transfer is from the dispersed to the continuous phase or from the continuous to the dispersed phase. Thorium nitrate was extracted and reextracted using both modes of operation. Both HETS and HTU were obtained. The aqueous continuous column gave much shorter HTU than the organic continuous column. In reextraction the organic continuous column gave shorter HTU. The Thorex-processes for uranium and thorium co-extraction, co-stripping, and partitioning were studied. Both acid feed solution and acid deficiend feed solution were investigated. The concentration profiles along the column height were obtained. The data were analysed with McCABE-THIELE diagrams to evaluate HETS. (orig./HP) [de

  14. Accelerator molten-salt breeding and thorium fuel cycle

    International Nuclear Information System (INIS)

    Furukawa, Kazuo; Nakahara, Yasuaki; Kato, Yoshio; Ohno, Hideo; Mitachi, Kohshi.

    1990-01-01

    The recent efforts at the development of fission energy utilization have not been successful in establishing fully rational technology. A new philosophy should be established on the basis of the following three principles: (1) thorium utilization, (2) molten-salt fuel concept, and (3) separation of fissile-breeding and power-generating functions. Such philosophy is called 'Thorium Molten-Salt Nuclear Energy Synergetics [THORIMS-NES]'. The present report first addresses the establishment of 233 U breeding fuel cycle, focusing on major features of the Breeding and Chemical Processing Centers and a small molten-salt power station (called FUJI-II). The development of fissile producing breeders is discussed in relation to accelerator molten-salt breeder (AMSB), impact fusion molten-salt breeder, and inertial-confined fusion hybrid molten-salt breeder. Features of the accelerator molten-salt breeder are described, focusing on technical problems with accelerator breeders (or spallators), design principle of the accelerator molten-salt breeder, selection of molten salt compositions, and nuclear- and reactor-chemical aspects of AMSB. Discussion is also made of further research and development efforts required in the future for AMSB. (N.K.)

  15. CO₂ Capture Membrane Process for Power Plant Flue Gas

    Energy Technology Data Exchange (ETDEWEB)

    Toy, Lora [Research Triangle Inst. International, Research Triangle Park, NC (United States); Kataria, Atish [Research Triangle Inst. International, Research Triangle Park, NC (United States); Gupta, Raghubir [Research Triangle Inst. International, Research Triangle Park, NC (United States)

    2012-04-01

    Because the fleet of coal-fired power plants is of such importance to the nation's energy production while also being the single largest emitter of CO₂, the development of retrofit, post-combustion CO₂ capture technologies for existing and new, upcoming coal power plants will allow coal to remain a major component of the U.S. energy mix while mitigating global warming. Post-combustion carbon capture technologies are an attractive option for coal-fired power plants as they do not require modification of major power-plant infrastructures, such as fuel processing, boiler, and steam-turbine subsystems. In this project, the overall objective was to develop an advanced, hollow-fiber, polymeric membrane process that could be cost-effectively retrofitted into current pulverized coal-fired power plants to capture at least 90% of the CO₂ from plant flue gas with 95% captured CO₂ purity. The approach for this project tackled the technology development on three different fronts in parallel: membrane materials R&D, hollow-fiber membrane module development, and process development and engineering. The project team consisted of RTI (prime) and two industrial partners, Arkema, Inc. and Generon IGS, Inc. Two CO₂-selective membrane polymer platforms were targeted for development in this project. For the near term, a next-generation, high-flux polycarbonate membrane platform was spun into hollow-fiber membranes that were fabricated into both lab-scale and larger prototype (~2,200 ft²) membrane modules. For the long term, a new fluoropolymer membrane platform based on poly(vinylidene fluoride) [PVDF] chemistry was developed using a copolymer approach as improved capture membrane materials with superior chemical resistance to flue-gas contaminants (moisture, SO₂, NOx, etc.). Specific objectives were: - Development of new, highly chemically resistant, fluorinated polymers as membrane materials with minimum selectivity of 30 for CO₂ over N₂ and CO

  16. SignalPlant: an open signal processing software platform.

    Science.gov (United States)

    Plesinger, F; Jurco, J; Halamek, J; Jurak, P

    2016-07-01

    The growing technical standard of acquisition systems allows the acquisition of large records, often reaching gigabytes or more in size as is the case with whole-day electroencephalograph (EEG) recordings, for example. Although current 64-bit software for signal processing is able to process (e.g. filter, analyze, etc) such data, visual inspection and labeling will probably suffer from rather long latency during the rendering of large portions of recorded signals. For this reason, we have developed SignalPlant-a stand-alone application for signal inspection, labeling and processing. The main motivation was to supply investigators with a tool allowing fast and interactive work with large multichannel records produced by EEG, electrocardiograph and similar devices. The rendering latency was compared with EEGLAB and proves significantly faster when displaying an image from a large number of samples (e.g. 163-times faster for 75  ×  10(6) samples). The presented SignalPlant software is available free and does not depend on any other computation software. Furthermore, it can be extended with plugins by third parties ensuring its adaptability to future research tasks and new data formats.

  17. Digital Process Management Technology for Nuclear Power Plants

    International Nuclear Information System (INIS)

    You, Young M.; Suh, Kune Y.

    2009-01-01

    PHILOSOPHIA, Inc. and Seoul National University have utilized the cutting edge Digital Process Management (DPM) technology for the good of Nuclear Power Plant in recent days. This work represent the overall benefits and the use of this new flow of technology which come into the spotlight. Before realizing the three dimensional (3D) technologies and applying it to real mechanical manufactures and constructions, majority of planning and designing works need huge time and cost even if the process is before the real work. Especially, for a massive construction such as power plant and harbor, without computer-aided technology currently we cannot imagine the whole process can be established easily. Computer-aided Design (CAD) is now main and common technology for manufacturing or construction. This technology lead the other virtual reality 3D technologies into the job site. As a member of these new technologies, DPM is utilized in high-tech and huge scale manufacturing and construction for the benefits of time and cost

  18. Plant senescence and proteolysis: two processes with one destiny.

    Science.gov (United States)

    Diaz-Mendoza, Mercedes; Velasco-Arroyo, Blanca; Santamaria, M Estrella; González-Melendi, Pablo; Martinez, Manuel; Diaz, Isabel

    2016-01-01

    Senescence-associated proteolysis in plants is a complex and controlled process, essential for mobilization of nutrients from old or stressed tissues, mainly leaves, to growing or sink organs. Protein breakdown in senescing leaves involves many plastidial and nuclear proteases, regulators, different subcellular locations and dynamic protein traffic to ensure the complete transformation of proteins of high molecular weight into transportable and useful hydrolysed products. Protease activities are strictly regulated by specific inhibitors and through the activation of zymogens to develop their proteolytic activity at the right place and at the proper time. All these events associated with senescence have deep effects on the relocation of nutrients and as a consequence, on grain quality and crop yield. Thus, it can be considered that nutrient recycling is the common destiny of two processes, plant senescence and, proteolysis. This review article covers the most recent findings about leaf senescence features mediated by abiotic and biotic stresses as well as the participants and steps required in this physiological process, paying special attention to C1A cysteine proteases, their specific inhibitors, known as cystatins, and their potential targets, particularly the chloroplastic proteins as source for nitrogen recycling.

  19. Processing of transuranic waste at the Savannah River Plant

    International Nuclear Information System (INIS)

    Daugherty, B.A.; Gruber, L.M.; Mentrup, S.J.

    1986-01-01

    Transuranic wastes at the Savannah River Plant (SRP) have been retrievably stored on concrete pads since early 1972. This waste is stored primarily in 55-gallon drums and large carbon steel boxes. Higher activity drums are placed in concrete culverts. In support of a National Program to consolidate and permanently dispose of this waste, a major project is planned at SRP to retrieve and process this waste. This project, the TRU Waste Facility (TWF), will provide equipment and processes to retrieve TRU waste from 20-year retrievable storage and prepare it for permanent disposal at the Waste Isolation Pilot Plant (WIPP) geological repository in New Mexico. This project is an integral part of the SRP Long Range TRU Waste Management Program to reduce the amount of TRU waste stored at SRP. The TWF is designed to process 15,000 cubic feet of retrieved waste and 6200 cubic feet of newly generated waste each year of operation. This facility is designed to minimize direct personnel contact with the waste using state-of-the-art remotely operated equipment

  20. Defense waste processing facility project at the Savannah River Plant

    International Nuclear Information System (INIS)

    Baxter, R.G.; Maher, R.; Mellen, J.B.; Shafranek, L.F.; Stevens, W.R. III.

    1984-01-01

    The Du Pont Company is building for the Department of Energy a facility to vitrify high-level waste at the Savannah River Plant near Aiken, South Carolina. The Defense Waste Processing Facility (DWPF) will solidify existing and future radioactive wastes produced by defense activities at the site. At the present time engineering and design are 45% complete, the site has been cleared, and startup is expected in 1989. This paper will describe project status as well as features of the design. 9 figures

  1. Computer simulations for thorium doped tungsten crystals

    Energy Technology Data Exchange (ETDEWEB)

    Eberhard, Bernd

    2009-07-17

    Tungsten has the highest melting point among all metals in the periodic table of elements. Furthermore, its equilibrium vapor pressure is by far the lowest at the temperature given. Thoria, ThO{sub 2}, as a particle dopant, results in a high temperature creep resistant material. Moreover, thorium covered tungsten surfaces show a drastically reduced electronic work function. This results in a tremendous reduction of tip temperatures of cathodes in discharge lamps, and, therefore, in dramatically reduced tungsten vapor pressures. Thorium sublimates at temperatures below those of a typical operating cathode. For proper operation, a diffusional flow of thorium atoms towards the surface has to be maintained. This atomic flux responds very sensitively on the local microstructure, as grain boundaries as well as dislocation cores offer ''short circuit paths'' for thorium atoms. In this work, we address some open issues of thoriated tungsten. A molecular dynamics scheme (MD) is used to derive static as well as dynamic material properties which have their common origin in the atomistic behavior of tungsten and thorium atoms. The interatomic interactions between thorium and tungsten atoms are described within the embedded atom model (EAM). So far, in literature no W-Th interaction potentials on this basis are described. As there is no alloying system known between thorium and tungsten, we have determined material data for the fitting of these potentials using ab-initio methods. This is accomplished using the full potential augmented plane wave method (FLAPW), to get hypothetical, i.e. not occurring in nature, ''alloy'' data of W-Th. In order to circumvent the limitations of classical (NVE) MD schemes, we eventually couple our model systems to external heat baths or volume reservoirs (NVT, NPT). For the NPT ensemble, we implemented a generalization of the variable cell method in combination with the Langevin piston, which results in a

  2. Computer simulations for thorium doped tungsten crystals

    International Nuclear Information System (INIS)

    Eberhard, Bernd

    2009-01-01

    Tungsten has the highest melting point among all metals in the periodic table of elements. Furthermore, its equilibrium vapor pressure is by far the lowest at the temperature given. Thoria, ThO 2 , as a particle dopant, results in a high temperature creep resistant material. Moreover, thorium covered tungsten surfaces show a drastically reduced electronic work function. This results in a tremendous reduction of tip temperatures of cathodes in discharge lamps, and, therefore, in dramatically reduced tungsten vapor pressures. Thorium sublimates at temperatures below those of a typical operating cathode. For proper operation, a diffusional flow of thorium atoms towards the surface has to be maintained. This atomic flux responds very sensitively on the local microstructure, as grain boundaries as well as dislocation cores offer ''short circuit paths'' for thorium atoms. In this work, we address some open issues of thoriated tungsten. A molecular dynamics scheme (MD) is used to derive static as well as dynamic material properties which have their common origin in the atomistic behavior of tungsten and thorium atoms. The interatomic interactions between thorium and tungsten atoms are described within the embedded atom model (EAM). So far, in literature no W-Th interaction potentials on this basis are described. As there is no alloying system known between thorium and tungsten, we have determined material data for the fitting of these potentials using ab-initio methods. This is accomplished using the full potential augmented plane wave method (FLAPW), to get hypothetical, i.e. not occurring in nature, ''alloy'' data of W-Th. In order to circumvent the limitations of classical (NVE) MD schemes, we eventually couple our model systems to external heat baths or volume reservoirs (NVT, NPT). For the NPT ensemble, we implemented a generalization of the variable cell method in combination with the Langevin piston, which results in a set of Langevin equations, i.e. stochastic

  3. Uranium and thorium deposits of Northern Ontario

    International Nuclear Information System (INIS)

    Robertson, J.A.; Gould, K.L.

    1983-01-01

    This, the second edition of the uranium-thorium deposit inventory, describes briefly the deposits of uranium and/or thorium in northern Ontario, which for the purposes of this circular is defined as that part of Ontario lying north and west of the Grenville Front. The most significant of the deposits described are fossil placers lying at or near the base of the Middle Precambrian Huronian Supergroup. These include the producing and past-producing mines of the Elliot Lake - Agnew Lake area. Also included are the pitchblende veins spatially associated with Late Precambrian (Keweenawan) diabase dikes of the Theano Point - Montreal River area. Miscellaneous Early Precambrian pegmatite, pitchblende-coffinite-sulphide occurrences near the Middle-Early Precambrian unconformity fringing the Lake Superior basin, and disseminations in diabase, granitic rocks, alkalic complexes and breccias scattered throughout northern Ontario make up the rest of the occurrences

  4. Thorium oxide dissolution kinetics for hydroxide and carbonate complexation

    International Nuclear Information System (INIS)

    Jardin, R.; Curran, V.; Czerwinski, K.R.

    2002-01-01

    The purpose of this project was to determine the kinetics and thermodynamics of thorium oxide dissolution in the environment. Solubility is important because it establishes an upper concentration limit on the concentration of a dissolved radionuclide in solution L1. While understanding the behavior of thorium fuels in the proposed repository at Yucca Mountain is most applicable, a more rigorous study of thorium solubility over a wide pH range was performed so that the data could also be used to model the behavior of thorium fuels in any environmental system. To achieve this, the kinetics and thermodynamics of thorium oxide dissolution under both pure argon and argon with P CO2 of 0. 1 were studied under the full pH range available in each atmosphere. In addition, thorium oxide powder remnants were studied after each experiment to examine structural changes that may affect kinetics

  5. Thorium: An energy source for the world of tomorrow

    Directory of Open Access Journals (Sweden)

    Revol J.-P.

    2015-01-01

    Full Text Available To meet the tremendous world energy needs, systematic R&D has to be pursued to replace fossil fuels. Nuclear energy, which produces no green house gases and no air pollution, should be a leading candidate. How nuclear energy, based on thorium rather than uranium, could be an acceptable solution is discussed. Thorium can be used both to produce energy and to destroy nuclear waste. The thorium conference, organized by iThEC at CERN in October 2013, has shown that thorium is seriously considered by some major developing countries as a key element of their energy strategy. However, developed countries do not seem to move fast enough in that direction, while global cooperation is highly desirable in this domain. Thorium is not fissile. Various possible ways of using thorium will be reviewed. However, an elegant option is to drive an “Accelerator Driven System (ADS” with a proton accelerator, as suggested by Nobel Prize laureate Carlo Rubbia .

  6. Thorium: An energy source for the world of tomorrow ?

    CERN Multimedia

    CERN. Geneva

    2014-01-01

    To meet the tremendous world energy needs, systematic R&D has to be pursued to replace fossil fuels. The ThEC13 conference organized by iThEC at CERN last October has shown that thorium is seriously considered by developing countries as a key element of their energy strategy. Developed countries are also starting to move in the same direction. How thorium could make nuclear energy (based on thorium) acceptable to society will be discussed. Thorium can be used both to produce energy and to destroy nuclear waste. As thorium is not fissile, one elegant option is to use an accelerator, in so-called “Accelerator Driven Systems (ADS)”, as suggested by Carlo Rubbia. CERN’s important contributions to R&D on thorium related issues will be mentioned as well as the main areas where CERN could contribute to this field in the future.

  7. Install and operate type radiation processing plant for marine products

    Energy Technology Data Exchange (ETDEWEB)

    Kohli, A.K. [BARC-BTIR Complex, Mumbai (India). Dept. of Atomic Energy. Board of Radiation and Isotope Technology

    2002-07-01

    Marine products can be carrier of several pathogens. Radiation processing is a very useful technique that is used to eliminate pathogens and also to extend shelf life of fresh fish. For marine products three processes are involved namely: radurization to pasteurize fresh chilled fish for extending shelf life; radicidation to sanitize frozen fishery products by elimination of pathogenic microorganisms and radiation disinfestations to eliminate insects from dehydrated fishery products. The paper brings out conceptual design of a compact radiation processing plant that can cater to all the three processes. The design is different from conveyor type of designs. The design is specially configured to maintain the temperature of frozen products and overdose ratio within limits specified. The throughput depends upon the source strength, type of product, the size of box and its configuration in which these could be arranged. The design has many features, which make it a very safe, convenient and economical method for processing of such items or for that matter all the food products, which are amenable for radiation processing. (author)

  8. Digital image processing for radiography in nuclear power plants

    International Nuclear Information System (INIS)

    Heidt, H.; Rose, P.; Raabe, P.; Daum, W.

    1985-01-01

    With the help of digital processing of radiographic images from reactor-components it is possible to increase the security and objectiveness of the evaluation. Several examples of image processing procedures (contrast enhancement, density profiles, shading correction, digital filtering, superposition of images etc.) show the advantages for the visualization and evaluation of radiographs. Digital image processing can reduce some of the restrictions of radiography in nuclear power plants. In addition a higher degree of automation can be cost-saving and increase the quality of radiographic evaluation. The aim of the work performed was to to improve the readability of radiographs for the human observer. The main problem is lack of contrast and the presence of disturbing structures like weld seams. Digital image processing of film radiographs starts with the digitization of the image. Conventional systems use TV-cameras or scanners and provide a dynamic range of 1.5. to 3 density units, which are digitized to 256 grey levels. For the enhancement process it is necessary that the grey level range covers the density range of the important regions of the presented film. On the other hand the grey level coverage should not be wider than necessary to minimize the width of digitization steps. Poor digitization makes flaws and cracks invisible and spoils all further image processing

  9. Install and operate type radiation processing plant for marine products

    International Nuclear Information System (INIS)

    Kohli, A.K.

    2002-01-01

    Marine products can be carrier of several pathogens. Radiation processing is a very useful technique that is used to eliminate pathogens and also to extend shelf life of fresh fish. For marine products three processes are involved namely: radurization to pasteurize fresh chilled fish for extending shelf life; radicidation to sanitize frozen fishery products by elimination of pathogenic microorganisms and radiation disinfestations to eliminate insects from dehydrated fishery products. The paper brings out conceptual design of a compact radiation processing plant that can cater to all the three processes. The design is different from conveyor type of designs. The design is specially configured to maintain the temperature of frozen products and overdose ratio within limits specified. The throughput depends upon the source strength, type of product, the size of box and its configuration in which these could be arranged. The design has many features, which make it a very safe, convenient and economical method for processing of such items or for that matter all the food products, which are amenable for radiation processing. (author)

  10. Vacuolar processing enzyme in plant programmed cell death

    Directory of Open Access Journals (Sweden)

    Noriyuki eHatsugai

    2015-04-01

    Full Text Available Vacuolar processing enzyme (VPE is a cysteine proteinase originally identified as the proteinase responsible for the maturation and activation of vacuolar proteins in plants, and it is known to be an orthologue of animal asparaginyl endopeptidase (AEP/VPE/legumain. VPE has been shown to exhibit enzymatic properties similar to that of caspase 1, which is a cysteine protease that mediates the programmed cell death (PCD pathway in animals. Although there is limited sequence identity between VPE and caspase 1, their predicted three-dimensional structures revealed that the essential amino-acid residues for these enzymes form similar pockets for the substrate peptide YVAD. In contrast to the cytosolic localization of caspases, VPE is localized in vacuoles. VPE provokes vacuolar rupture, initiating the proteolytic cascade leading to PCD in the plant immune response. It has become apparent that the VPE-dependent PCD pathway is involved not only in the immune response, but also in the responses to a variety of stress inducers and in the development of various tissues. This review summarizes the current knowledge on the contribution of VPE to plant PCD and its role in vacuole-mediated cell death, and it also compares VPE with the animal cell death executor caspase 1.

  11. Scaling root processes based on plant functional traits (Invited)

    Science.gov (United States)

    Eissenstat, D. M.; McCormack, M. L.; Gaines, K.; Adams, T.

    2013-12-01

    There are great challenges to scaling root processes as variation across species and variation of a particular species over different spatial and temporal scales is poorly understood. We have examined tree species variation using multispecies plantings, often referred to by ecologists as 'common gardens'. Choosing species with wide variation in growth rate, root morphology (diameter, branching intensity) and root chemistry (root N and Ca concentration), we found that variation in root lifespan was well correlated with plant functional traits across 12 species. There was also evidence that localized liquid N addition could increase root lifespan and localized water addition diminished root lifespan over untreated controls, with effects strongest in the species of finest root diameter. In an adjacent forest, we have also seen tree species variation in apparent depth of rooting using water isotopes. In particular species of wood anatomy that was ring porous (e.g. oaks) typically had the deepest rooting depth, whereas those that had either diffuse-porous sapwood (maples) or tracheid sapwood (pines) were shallower rooted. These differences in rooting depth were related to sap flux of trees during and immediately after periods of drought. The extent that the patterns observed in central Pennsylvania are modulated by environment or indicative of other plant species will be discussed.

  12. Intensifying drying process with creation of functional plant compositions

    Directory of Open Access Journals (Sweden)

    Zh. Petrova

    2015-05-01

    Full Text Available Introduction. The process of drying agricultural raw products is associated with loss of bioactive substances by the products exposed to heat, light, oxygen, or рН medium. It is reasonable to enhance the table beet processing technology in order to achieve maximum betanin conservation at lower energy consumption. Materials and methods. Table beets, rhubarbs, lemons, and tomatoes were dried at temperature of 50 to 100 ºС, air speed of 1.5 to 3.5 m/s, heat carrier water content of 7 to 15 g/kg, and layer thickness of 2 to 20 mm. The betanіn content was determined via absorption spectra, using the optical density value at 540 nm wavelength. A differential microcalorimeter was used for measuring evaporation heat consumption. Results and discussion.The effect of raw product pre-drying preparation was studied. With no preliminary preparation, the loss of betanin after drying reaches 66 %. The preliminary preparation technology we have developed includes boiling whole root crops with optimal selection of acid medium and allows us to reduce the betanin loss down to 6 %. Regretfully, the process requires large energy consumption. Low energy consumption pre-drying preparation method was developed for antioxidant raw products with thermal processing replaced by blending. The betanin loss, in this case, does not exceed 5 %. Optimal drying temperature of betanin-containing raw stock, after its preliminary processing, is 60 °С. It allows to keep up to 95 % of betanіn. Specific heat consumption for water evaporation out of the developed table beet based antioxidant plant compositions, with addition of rhubarb and lemon, is less by 4 to 5 % as compared to the initial components. Conclusions. Dependence of betanin loss in plant raw stock on the material temperature and composition components, in the course of their pre-drying preparation, was found. It was also found that water evaporation heat, for some antioxidant plant compositions developed, is less

  13. Improving sustainability of maize to ethanol processing by plant breeding and process optimization

    NARCIS (Netherlands)

    Slegers, P.M.; Torres Salvador, A.F.; Boxtel, van A.J.B.; Trindade, L.M.

    2017-01-01

    Efficient management of plant resources is essential for a sustainable biobased economy. The biomass conversion efficiency and sustainability performance depend greatly on the choice of feedstock and the applied processing technology. The aim of this research was to enhance the biomass use of maize

  14. Thorium as a substitute for uranium

    International Nuclear Information System (INIS)

    Hunt, H.

    1977-01-01

    Reference is made to the paper by E. Teller in Atom, February 1977, who suggested that it appears, at least theoretically, that the use of a thorium cycle in thermal reactors would give enough nuclear fuel for a long time to come, and so avoid the need for using Pu in fast reactors. This appears at first sight to be an attractive proposition, but loses some of this attraction on close examination. Reasons for this are discussed. (U.K.)

  15. Thorium dioxide: properties and nuclear applications

    International Nuclear Information System (INIS)

    Belle, J.; Berman, R.M.

    1984-01-01

    This is the sixth book on reactor materials published under sponsorship of the Naval Reactors Office of the United States Department of Energy, formerly the United States Atomic Energy Commission. This book presents a comprehensive compilation of the most significant properties of thorium dioxide, much like the book Uranium Dioxide: Properties and Nuclear Applications presented information on the fuel material used in the Shippingport Pressurized Water Reactor core

  16. Long term radiological impact of thorium extraction

    International Nuclear Information System (INIS)

    Menard, S.; Schapira, J.P.

    1995-01-01

    Thorium extraction produces a certain amount of radioactive wastes. Potential long term radiological impact of these residues has been calculated using the recent ICRP-68 ingestion dose factors in connection with the computing code DECAY, developed at Orsay and described in this work. This code solves the well known Bateman's equations which govern the time dependence of a set of coupled radioactive nuclei. Monazites will be very likely the minerals to be exploited first, in case of an extensive use of thorium as nuclear fuel. Because monazites contain uranium as well, mining residues will contain not only the descendants of 232 Th and a certain proportion of non-extracted thorium (taken here to be 5%), but also this uranium, if left in the wastes for economical reasons. If no uranium would be present at all in the mineral, the potential radiotoxicity would strongly decrease in approximately 60 years, at the pace of the 5.8 years period of 228 Ra, which becomes the longest-lived radionuclide of the 4n radioactive family in the residues. Moreover, there is no risk due to radon exhalation, because of the very short period of 220 Rn. These significant differences between uranium and thorium mining have to be considered in view of some estimated long term real radiological impacts due to uranium residues, which could reach a value of the order of 1 mSv/year, the dose limit recommended for the public by the recent ICRP-60. (authors). 15 refs., 4 figs., 3 tabs., 43 appendices

  17. Thorium dioxide: properties and nuclear applications

    Energy Technology Data Exchange (ETDEWEB)

    Belle, J.; Berman, R.M. (eds.)

    1984-01-01

    This is the sixth book on reactor materials published under sponsorship of the Naval Reactors Office of the United States Department of Energy, formerly the United States Atomic Energy Commission. This book presents a comprehensive compilation of the most significant properties of thorium dioxide, much like the book Uranium Dioxide: Properties and Nuclear Applications presented information on the fuel material used in the Shippingport Pressurized Water Reactor core.

  18. Structure of tetrakis(salicylaldehydato)thorium(IV)

    Energy Technology Data Exchange (ETDEWEB)

    Hill, R J; Rickard, C E.F. [Auckland Univ. (New Zealand). Dept. of Chemistry

    1977-01-01

    The structure of tetrakis(salicylaldehydato)thorium(IV) has been determined by single crystal X-ray crystallography. The crystals are tetragonal, a = 10.214, b = 23.744 A, space group P4/sub 1/. The molecules are eight coordinate, the coordination polyhedron being a dodecahedron with approximate Dsub(2d) symmetry. The dodecahedral A sites are occupied by the aldehydic oxygens and the phenolic oxygens occupy the B sites.

  19. A PWR Thorium Pin Cell Burnup Benchmark

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, Kevan Dean; Zhao, X.; Pilat, E. E; Hejzlar, P.

    2000-05-01

    As part of work to evaluate the potential benefits of using thorium in LWR fuel, a thorium fueled benchmark comparison was made in this study between state-of-the-art codes, MOCUP (MCNP4B + ORIGEN2), and CASMO-4 for burnup calculations. The MOCUP runs were done individually at MIT and INEEL, using the same model but with some differences in techniques and cross section libraries. Eigenvalue and isotope concentrations were compared on a PWR pin cell model up to high burnup. The eigenvalue comparison as a function of burnup is good: the maximum difference is within 2% and the average absolute difference less than 1%. The isotope concentration comparisons are better than a set of MOX fuel benchmarks and comparable to a set of uranium fuel benchmarks reported in the literature. The actinide and fission product data sources used in the MOCUP burnup calculations for a typical thorium fuel are documented. Reasons for code vs code differences are analyzed and discussed.

  20. Self-Sustaining Thorium Boiling Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Greenspan, Ehud [Univ. of California, Berkeley, CA (United States); Gorman, Phillip M. [Univ. of California, Berkeley, CA (United States); Bogetic, Sandra [Univ. of California, Berkeley, CA (United States); Seifried, Jeffrey E. [Univ. of California, Berkeley, CA (United States); Zhang, Guanheng [Univ. of California, Berkeley, CA (United States); Varela, Christopher R. [Univ. of California, Berkeley, CA (United States); Fratoni, Massimiliano [Univ. of California, Berkeley, CA (United States); Vijic, Jasmina J. [Univ. of California, Berkeley, CA (United States); Downar, Thomas [Univ. of Michigan, Ann Arbor, MI (United States); Hall, Andrew [Univ. of Michigan, Ann Arbor, MI (United States); Ward, Andrew [Univ. of Michigan, Ann Arbor, MI (United States); Jarrett, Michael [Univ. of Michigan, Ann Arbor, MI (United States); Wysocki, Aaron [Univ. of Michigan, Ann Arbor, MI (United States); Xu, Yunlin [Univ. of Michigan, Ann Arbor, MI (United States); Kazimi, Mujid [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Shirvan, Koroush [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Mieloszyk, Alexander [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Todosow, Michael [Brookhaven National Lab. (BNL), Upton, NY (United States); Brown, Nicolas [Brookhaven National Lab. (BNL), Upton, NY (United States); Cheng, Lap [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-03-15

    The primary objectives of this project are to: Perform a pre-conceptual design of a core for an alternative to the Hitachi proposed fuel-self- sustaining RBWR-AC, to be referred to as a RBWR-Th. The use of thorium fuel is expected to assure negative void coefficient of reactivity (versus positive of the RBWR-AC) and improve reactor safety; Perform a pre-conceptual design of an alternative core to the Hitachi proposed LWR TRU transmuting RBWR-TB2, to be referred to as the RBWR-TR. In addition to improved safety, use of thorium for the fertile fuel is expected to improve the TRU transmutation effectiveness; Compare the RBWR-Th and RBWR-TR performance against that of the Hitachi RBWR core designs and sodium cooled fast reactor counterparts - the ARR and ABR; and, Perform a viability assessment of the thorium-based RBWR design concepts to be identified along with their associated fuel cycle, a technology gap analysis, and a technology development roadmap. A description of the work performed and of the results obtained is provided in this Overview Report and, in more detail, in the Attachments. The major findings of the study are summarized.

  1. Self-Sustaining Thorium Boiling Water Reactors

    International Nuclear Information System (INIS)

    Greenspan, Ehud; Gorman, Phillip M.; Bogetic, Sandra; Seifried, Jeffrey E.; Zhang, Guanheng; Varela, Christopher R.; Fratoni, Massimiliano; Vijic, Jasmina J.; Downar, Thomas; Hall, Andrew; Ward, Andrew; Jarrett, Michael; Wysocki, Aaron; Xu, Yunlin; Kazimi, Mujid; Shirvan, Koroush; Mieloszyk, Alexander; Todosow, Michael; Brown, Nicolas; Cheng, Lap

    2015-01-01

    The primary objectives of this project are to: Perform a pre-conceptual design of a core for an alternative to the Hitachi proposed fuel-self- sustaining RBWR-AC, to be referred to as a RBWR-Th. The use of thorium fuel is expected to assure negative void coefficient of reactivity (versus positive of the RBWR-AC) and improve reactor safety; Perform a pre-conceptual design of an alternative core to the Hitachi proposed LWR TRU transmuting RBWR-TB2, to be referred to as the RBWR-TR. In addition to improved safety, use of thorium for the fertile fuel is expected to improve the TRU transmutation effectiveness; Compare the RBWR-Th and RBWR-TR performance against that of the Hitachi RBWR core designs and sodium cooled fast reactor counterparts - the ARR and ABR; and, Perform a viability assessment of the thorium-based RBWR design concepts to be identified along with their associated fuel cycle, a technology gap analysis, and a technology development roadmap. A description of the work performed and of the results obtained is provided in this Overview Report and, in more detail, in the Attachments. The major findings of the study are summarized.

  2. Self-Sustaining Thorium Boiling Water Reactors

    Directory of Open Access Journals (Sweden)

    Ehud Greenspan

    2012-10-01

    Full Text Available A thorium-fueled water-cooled reactor core design approach that features a radially uniform composition of fuel rods in stationary fuel assembly and is fuel-self-sustaining is described. This core design concept is similar to the Reduced moderation Boiling Water Reactor (RBWR proposed by Hitachi to fit within an ABWR pressure vessel, with the following exceptions: use of thorium instead of depleted uranium for the fertile fuel; elimination of the internal blanket; and elimination of absorbers from the axial reflectors, while increasing the length of the fissile zone. The preliminary analysis indicates that it is feasible to design such cores to be fuel-self-sustaining and to have a comfortably low peak linear heat generation rate when operating at the nominal ABWR power level of nearly 4000 MWth. However, the void reactivity feedback tends to be too negative, making it difficult to have sufficient shutdown reactivity margin at cold zero power condition. An addition of a small amount of plutonium from LWR used nuclear fuel was found effective in reducing the magnitude of the negative void reactivity effect and enables attaining adequate shutdown reactivity margin; it also flattens the axial power distribution. The resulting design concept offers an efficient incineration of the LWR generated plutonium in addition to effective utilization of thorium. Additional R&D is required in order to arrive at a reliable practical and safe design.

  3. Thorium: in search of a global solution

    CERN Multimedia

    Antonella Del Rosso

    2013-01-01

    Last week, an international conference held at CERN brought together the world’s main experts in the field of alternative nuclear technology for the first time to discuss the use of thorium for the production of energy and the destruction of nuclear waste. Among the different technologies presented and discussed at the conference was ADS (Accelerator-Driven Systems) which relies primarily on particle accelerators.   The conference Chair (far left), the organisers and some of the distinguished participants of the ThEC13 conference held at CERN from 27 to 31 October 2013. “CERN has always been interested in finding ways in which fundamental research can help to resolve the problems of society,” says Jean-Pierre Revol, a physicist at the ALICE experiment who recently retired from CERN and is President of iThEC, the international not-for-profit organisation which promotes research and development in the field of thorium and which organised the Thorium Energy 2013 (Th...

  4. Prototype plant for nuclear process heat (PNP), reference phase

    International Nuclear Information System (INIS)

    Fladerer, R.; Schrader, L.

    1982-07-01

    The coal gasification processes using nuclear process heat being developed within the framwork of the PNP project, have the advantages of saving feed coal, improving efficiency, reducing emissions, and stabilizing energy costs. One major gasification process is the hydrogasification of coal for producing SNG or gas mixture of carbon monoxide and hydrogen; this process can also be applied in a conventional route. The first steps to develop this process were planning, construction and operation of a semi-technical pilot plant for hydrogasification of coal in a fluidized bed having an input of 100 kg C/h. Before the completion of the development phase (reference phase) describing here, several components were tested on part of which no operational experience had so far been gained; these were the newly developed devices, e.g. the inclined tube for feeding coal into the fluidized bed, and the raw gas/hydrogenation gas heat exchanger for utilizing the waste heat of the raw gas leaving the gasifier. Concept optimizing of the thoroughly tested equipment parts led to an improved operational behaviour. Between 1976 and 1980, the semi-technical pilot plant was operated for about 19,400 hours under test conditions, more than 7,400 hours of which it has worked under gasification conditions. During this time approx. 1,100 metric tons of dry brown coal and more than 13 metric tons of hard coal were gasified. The longest coherent operational phase under gasification conditions was 748 hours in which 85.4 metric tons of dry brown coal were gasified. Carbon gasification rates up to 82% and methane contents in the dry raw gas (free of N 2 ) up to 48 vol.% were obtained. A detailed evaluation of the test results provided information of the results obtained previously. For the completion of the test - primarily of long-term tests - the operation of the semi-technical pilot plant for hydrogasification of coal is to be continued up to September 1982. (orig.) [de

  5. Public hearing process for nuclear power plants. Seminar report

    International Nuclear Information System (INIS)

    1979-02-01

    On June 26 and 27, 1978, the Nuclear Regulatory Commission conducted a seminar on the public hearing process for nuclear power plants. The seminar was intended to examine current practices regarding the conduct of public hearings and how these practices related to the statutory intent, to assess whether existing procedures are being followed, and to explore whether administrative or legal changes are warranted. The seminar format allowed exchanges of views among participants in the hearing process and was attended by members of the public, the General Accounting Office, Congressional staffs, NRC, and the nuclear industry. The report contains panel reports on scheduling of public hearings, procedures for Board notification, selection and training of panel members, hearing procedures, and Board functions

  6. Liquid radioactive waste processing system for pressurized water reactor plants

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    This Standard sets forth design, construction, and performance requirements, with due consideration for operation, of the Liquid Radioactive Waste Processing System for pressurized water reactor plants for design basis inputs. For the purpose of this Standard, the Liquid Radioactive Waste Processing System begins at the interfaces with the reactor coolant pressure boundary and the interface valve(s) in lines from other systems, or at those sumps and floor drains provided for liquid waste with the potential of containing radioactive material; and it terminates at the point of controlled discharge to the environment, at the point of interface with the waste solidification system, and at the point of recycle back to storage for reuse

  7. Radioactive properties of medicinal plants

    International Nuclear Information System (INIS)

    Ahmedova, G.A.

    2003-01-01

    Full text: A complicated cycle of various compounds' synthesis is provided by plants in the process of their development. The synthesized compounds are necessary to maintain the life of all living organisms both in water and on the land. Together with the organic compounds all known natural radionuclides are accumulated by the plants. Many plants possess the ability to accumulate some elements, whose concentration in the plants may be much higher than that in the soils and water sources. It is well known that the plants are basic or initial raw materials for producing numerous food products, as well as medicinal preparations. The radionuclides, accumulated in the plants, may pass to the human organism through the products and drugs, and may become a source of internal radiation. Accumulation of the radionuclides in various human organs above the maximal acceptable concentration (MAC) may lead to various pathologic changes. That is why it is a necessary and urgent problem to carry out investigations of the radioactive properties of the plants (i.e. to determine their radioecological cleanliness) before using the medicinal plant for pharmacological purposes. In the present work we investigated the radioactive processes of kinds of medicinal plants by the method of semi-conductor gamma-spectrometry. Measurements of the gamma-spectra of the plants' leach were carried out with the help of a gamma-spectrometer with a Ge(Li) detector accompanied by a 4096-channel analyzer. Responsive volume of the detector was 40 cm 3 , energy resolution with respect to 1333 keV 60 Co line was 3 keV. In the measured spectra we observed clearly photo-peaks belonging to uranium-238 family: 186 keV 226 Ra; 295, 351 keV 214 Pb; 609, 1120, 1764 keV 214 Bi; and those belonging to thorium - 232 family: 339, 911, 968 keV 2 28 Ac; 583, 2614 keV 208 Te; as well as the photo-peak of the natural radionuclide 40 K with the energy 1460 keV. From the proper gamma-lines, observed in the spectra, we

  8. Health status and body radioactivity of former thorium workers

    International Nuclear Information System (INIS)

    Stehney, A.F.; Polednak, A.P.; Rundo, J.; Brues, A.M.; Lucas, H.F. Jr.; Patten, B.C.; Rowland, R.E.

    1981-01-01

    The objectives of the study are: (1) to assess possible health effects of employment in the thorium milling industry by comparison of mortality and morbidity characteristics of former thorium workers with those of suitable general populations; (2) to examine disease outcomes by estimated exposure levels of thorium and thoron daughter products for possible radiation-related effects; and (3) to determine the body distribution of inhaled thorium (and daughters) and rare earths in humans by radioactivity measurements in vivo and by analysis of autopsy samples. The principal end points for investigation are respiratory disease and cancers of lung, liver, bone, and bone marrow

  9. Liquid radioactive waste processing improvement of PWR nuclear power plants

    International Nuclear Information System (INIS)

    Nery, Renata Wolter dos Reis; Martinez, Aquilino Senra; Monteiro, Jose Luiz Fontes

    2005-01-01

    The study evaluate an inorganic ion exchange to process the low level liquid radwaste of PWR nuclear plants, so that the level of the radioactivity in the effluents and the solid waste produced during the treatment of these liquid radwaste can be reduced. The work compares two types of ion exchange materials, a strong acid cation exchange resin, that is the material typically used to remove radionuclides from PWR nuclear plants wastes, and a mordenite zeolite. These exchange material were used to remove cesium from a synthetic effluent containing only this ion and another effluent containing cesium and cobalt. The breakthrough curves of the zeolite and resin using a fix bed reactor were compared. The results demonstrated that the zeolite is more efficient than the resin in removing cesium from a solution containing cesium and cobalt. The results also showed that a bed combining zeolite and resin can process more volume of an effluent containing cesium and cobalt than a bed resin alone. (author)

  10. Analytical Characterization of the Thorium Nitrate Stockpile

    Energy Technology Data Exchange (ETDEWEB)

    Mattus, CH

    2003-12-30

    For several years, Oak Ridge National Laboratory (ORNL) has been supporting the Defense Logistics Agency-Defense National Stockpile Center with stewardship of a thorium nitrate (ThN) stockpile. The effort for fiscal year 2002 was to prepare a sampling and analysis plan and to use the activities developed in the plan to characterize the ThN stockpile. The sampling was performed in June and July 2002 by RWE NUKEM with oversight by ORNL personnel. The analysis was performed by Southwest Research Institute of San Antonio, Texas, and data validation was performed by NFT, Inc., of Oak Ridge, Tennessee. Of the {approx} 21,000 drums in the stockpile, 99 were sampled and 53 were analyzed for total metals composition, radiological constituents (using alpha and gamma spectrometry), and oxidizing characteristics. Each lot at the Curtis Bay Depot was sampled. Several of the samples were also analyzed for density. The average density of the domestic ThN was found to be 1.89 {+-} 0.08 g/cm{sup 3}. The oxidizer test was performed following procedures issued by the United Nations in 1999. Test results indicated that none of the samples tested was a Division 5.1 oxidizer per Department of Transportation definition. The samples were analyzed for total metals following the U.S. Environmental Protection Agency methods SW-846-6010B and 6020 (EPA 2003) using a combination of inductively coupled plasma--atomic emission spectroscopy and inductively coupled plasma--mass spectroscopy techniques. The results were used to compare the composition of the eight Resource Conservation and Recovery Act metals present in the sample (arsenic, barium, cadmium, chromium, lead, mercury, selenium, and silver) to regulatory limits. None of the samples was found to be hazardous for toxicity characteristics. The radiological analyses confirmed, when possible, the results obtained by the inductively coupled plasma analyses. These results--combined with the historical process knowledge acquired on the material

  11. Aerosol release factor for Pu as a consequence of an ion exchange resin fire in the process cell of a fuel reprocessing plant

    Energy Technology Data Exchange (ETDEWEB)

    Bhanti, D.P.; Malvankar, S.V.; Kotrappa, P.; Somasundaram, S.; Raghunath, B.; Curtay, A.M.

    1988-12-01

    One of the upper limit accidents usually considered in the safety analysis of a fuel reprocessing plant is an accidental explosion, followed by a fire, of an ion exchange column containing resin loaded with large quantities of plutonium. In such accidents, a certain fraction (release factor) of Pu is released in the form of an aerosol into the ventilation system, and finally to the environment through HEPA filters and the stack. The present study was undertaken to determine the aerosol release factor for Pu in the process cell of a typical fuel reprocessing plant. Geometrically similar scaled-down models of three different sizes were built, and suitably scaled-down quantities of resin loaded with thorium in nitric acid medium were burnt in these model cells. Thorium was used in place of Pu because of its physical and chemical similarities with Pu. The release factor was obtained by comparing the amount of Th in air with the total. The study also dealt with aerosol characteristics and kinematics of process of fire. The aerosol release factors for the three models were found to lie in the range 0.01-0.07%, and varied non-monotonically with model size. The analysis of scaled down results in conjunction with simplified aerosol modelling yielded the release factor for the actual cell conditions as 0.012% with an upper limit value of 0.1%. The particle size analysis based on Th-radioactivity and particle-mass indicated nonuniform tagging of Th to aerosol particles. These particles were irregularly shaped, but not as long chain-like aggregates. The study proposes, with a reasonable degree of conservatism, the release factor of 0.1% for such fires, and aerosol parameters, AMAD and sigma/sub g/, as 2 m and 2 respectively. However, for situations significantly different from the present one, the release factor of 1% recommended by the American National Standards Institute may be used with a greater degree of confidence in the light of the present work.

  12. Fissile material holdup monitoring in the PREPP [Process Experimental Pilot Plant] process

    International Nuclear Information System (INIS)

    Becker, G.K.; Pawelko, R.J.

    1989-01-01

    The Process Experimental Pilot Plant (PREPP) is an incineration system designed to thermally process mixed transuranic (TRU) waste and TRU contaminated low-level waste. The TRU isotopic composition is that of weapons grade plutonium (Pu) which necessitates that criticality prevention measures by incorporated into the plant design and operation. Criticality safety in the PREPP process is assured through the utilization of mass and moderation control in conjunction with favorable vessel geometries. The subject of this paper concerns the Pu mass holdup instrumentation system which is an integral part of the inprocess mass control strategy. Plant vessels and components requiring real-time mass holdup measurements were selected based on their evaluated potential for achieving physically credible Pu mass loadings and associated parameters which could lead to a criticality event. If the parameters requisite to a criticality occurrence could not physically be achieved under credible plant conditions, the particular location only required periodic portable holdup monitoring. Based on these analyses five real-time holdup monitoring locations were identified for criticality assurance purposes. An additional real-time instrument is part of the system but serves primarily in the capacity of providing operational support data. 1 fig

  13. Geological development and uranium and thorium evolutions in volcanic basin No.460

    International Nuclear Information System (INIS)

    Zhou Dean.

    1989-01-01

    On the basis of summarizing the geological features and the developmental history of tectono-magmatic activity, the uranium and thorium evolutional rules of rocks in different times are studied. It is suggested that the uranium and thorium increments caused by potassic migmatization of late Archean basement rocks in this area is the material base which affected the subsequent evolution of the cover of volcanic rocks and uranium mineralization. The Upper Jurassic acid volcanic cover belonging to crustal remelting origin constituted the favorable stratigraphic background for uranium mineralization in this area due to its wide distribution, large thickness, various rock associations and lithological sequences, as well as high content of uranium and thorium. During the late Yanshanian stage acid subvolanic rocks or small intrusions with high uranium intruded along the regional fractures are the decisive factors for the emplacement of uranium mineralization in this area, which othen became the favorable wall rocks for preserving ores itself. During the late stage the hydrothermal uranium mineralization was the main geological process from which uranium and thorium in stratigraphy and terrain were finally separated

  14. Radiological implications of plutonium recycle and the use of thorium fuels in power reactor operations

    Energy Technology Data Exchange (ETDEWEB)

    Macdonald, H. F.

    1976-01-15

    As economically attractive sources of natural uranium are gradually depleted attention will turn to recycling plutonium or to the use of thorium fuels. The radiological implications of these fuel cycles in terms of fuel handling and radioactive waste disposal are investigated in relation to a conventional /sup 235/U enriched oxide fuel. It is suggested that a comparative study of this nature may be an important aspect of the overall optimization of future fuel cycle strategies. It is shown that the use of thorium based fuels has distinct advantages in terms of neutron dose rates from irradiated fuels and long term proportional to decay heating commitment compared with conventional uranium/plutonium fuels. However, this introduces a ..gamma.. dose rate problem in the fabrication and handling of unirradiated /sup 233/U fuels. For both plutonium and thorium fuels these radiological problems increase during storage of the fuel prior to reactor irradiation. The novel health physics problems which arise in the handling and processing of thorium fuels are reviewed in an appendix.

  15. Process Analysis in Chemical Plant by Means of Radioactive Tracers

    Energy Technology Data Exchange (ETDEWEB)

    Hirayama, T.; Hamada, K.; Osada, K. [Showa Denko K.K., Tokyo (Japan)

    1967-06-15

    Following the movement of solids and fluids is important in chemical processes to determine mixing efficiency and residence time. Since it is necessary to follow many complex substances such as raw materials, intermediates and reactants in plant investigations, it is often necessary to ascertain whether the behaviour of the radioisotope tracer and the substance to be traced are identical. The most difficult problem is to determine the best method of labelling, a factor which is a substantial key to the success of an experiment. Usually, there are three labelling techniques: radioisotope labelling, pre-.activation of the material and post-activation of the material. This paper deals with practical examples of the double-tracer technique, a combination of conventional radioisotope labelling and post-activation methods by means of activation analysis. In process analysis by means of tracers, a practical measurement method should also be devised and developed for each experiment. Phosphorus-32 and gold (non-radioactive) were used to measure retention time in a carbon-black plant. The radioisotope was pumped into a feed-stock pipe positioned before the reactor and samples were taken from each process of the plant, including the bag filter, mixer and product tank. After sampling from each step of the process, {sup 32}P in a semi-infinite powder sample was measured in situ by beta counting, and the gold was measured by gamma counting after activating the sample in a reactor. The experiment showed that both tracers had the same residence time, which was shorter than expected. Useful data were also obtained from the dispersion pattern of the material flow for future operation controls, including the time required to change from one grade of product to another. Practical tracer techniques to measure mixing characteristics in high-speed gas flows using {sup 85}Kr have been developed. A study of the measurement method was conducted by calculating the differential values of

  16. Radiotoxicity Characterization of Multi-Recycled Thorium Fuel - 12394

    Energy Technology Data Exchange (ETDEWEB)

    Franceschini, F.; Wenner, M. [Westinghouse Electric Company, Cranberry Township, PA (United States); Fiorina, C. [Polytechnic of Milano, Milan (Italy); Paul Sherrer Institute (Switzerland); Huang, M.; Petrovic, B. [Georgia Technology University, Atlanta, GA (United States); Krepel, J. [Paul Sherrer Institute (Switzerland)

    2012-07-01

    substantial advantages compared to the U cycle, such as the smaller actinide radiotoxicity and decay heat for up to 25,000 years after irradiation. In order for these benefits to materialize, the capability to reprocess and remotely manufacture industrial amounts of recycled fuel appears to be the key. Westinghouse is proposing the implementation of a thorium based fuel cycle to burn the TRU contained in the current UNF. The general approach and the potential of thorium as TRU burner is described in other papers presented at this conference. The focus of this paper is to analyze the long-term potential of thorium, once the legacy TRU has been exhausted and the thorium reactor system will become self-sufficient. Therefore, a comparison of Th closed cycle, in fast and thermal neutron energy ranges, vs. U closed cycle, in the fast energy range, has been undertaken. The results presented focus on selected backend and front-end metrics: isotopic actinide composition and potential implications on ingested radiotoxicity, decay heat and gamma heat. The evaluation confirms potential substantial improvements in the backend of the fuel cycle by transitioning to a thorium closed cycle. These benefits are the result of a much lower TRU content, in particular Pu-241, Am-241 and Pu-240, characterizing the Th vs. U actinide inventories, and the ensuing process waste to be disposed. On the other hand, the larger gamma activity of Th recycled fuel, consisting predominantly of hard gammas from U-232's decay products, is a significant challenge for fuel handling, transportation and manufacturing but can be claimed as beneficial for the proliferation resistance of the fuel. It is worth remembering that in our perspective the Th closed cycle and the U closed cycle will follow a transmutation phase which will likely take place over several decades and dictate the technologies required. These will likely include remote fuel manufacturing, regardless of the specific system adopted for the

  17. Quantitative analysis of thorium-containing materials using an Industrial XRF analyzer

    International Nuclear Information System (INIS)

    Hasikova, J.; Titov, V.; Sokolov, A.

    2014-01-01

    Thorium (Th) as nuclear fuel is clean and safe and offers significant advantages over uranium. The technology for several types of thorium reactors is proven but still must be developed on a commercial scale. In the case of commercialization of thorium nuclear reactor thorium raw materials will be on demand. With this, mining and processing companies producing Th and rare earth elements will require prompt and reliable methods and instrumentation for Th quantitative on-line analysis. Potential applicability of X-ray fluorescence conveyor analyzer CON-X series is discussed for Th quantitative or semi-quantitative on-line measurement in several types of Th-bearing materials. Laboratory study of several minerals (zircon sands and limestone as unconventional Th resources; monazite concentrate as Th associated resources and uranium ore residues after extraction as a waste product) was performed and analyzer was tested for on-line quantitative measurements of Th contents along with other major and minor components. Th concentration range in zircon sand is 50-350 ppm; its detection limit at this level is estimated at 25- 50 ppm in 5 minute measurements depending on the type of material. On-site test of the CON-X analyzer for continuous analysis of thorium traces along with other elements in zircon sand showed that accuracy of Th measurements is within 20% relative. When Th content is higher than 1% as in the concentrate of monazite ore (5-8% ThO_2) accuracy of Th determination is within 1% relative. Although preliminary on-site test is recommended in order to address system feasibility at a large scale, provided results show that industrial conveyor XRF analyzer CON-X series can be effectively used for analytical control of mining and processing streams of Th-bearing materials. (author)

  18. Improved liquid waste processing system of PWR plant

    International Nuclear Information System (INIS)

    Suehiro, Kazuyasu

    1977-01-01

    Mitsubishi Heavy Industries, Ltd. has engaged in the improvement and enhancement of waste-processing facilities for PWR power stations, and recently established the improved processing system. With this system, it becomes possible to contain radioactive waste gas semi-permanently within plants and to recycle waste liquid after the treatment, thus to make the release of radioactive wastes practically zero. The improved system has the following features, namely the recycling system is adopted, drain is separated and each separated drain is treated by specialized process, the reboiler type evaporator and the reverse osmosis equipment are used, and the leakless construction is adopted for the equipments. The radioactive liquid wastes in PWR power stations are classified into coolant drain, drain from general equipments, chemical drain and cleaning water. The outline of the improved processing system and the newly developed equipments such as the reboiler type evaporator and the reverse osmosis equipment are explained. With the evaporator, the concentration rate of waste liquid can be raised to about three times, and foaming waste can be treated efficiently. The decontamination performance is excellent. The reverse osmosis treatment is stable and reliable method, and is useful for the treatment of cleaning water. It is also effective for concentrating treatment. The unmanned automatic operation is possible. (Kako, I.)

  19. Feed type based expert systems in mineral processing plants

    International Nuclear Information System (INIS)

    Jamsa-Jounela, S.-L.; Laine, S.; Laurila, H.

    1999-01-01

    Artificial Intelligence includes excellent tools for the control and supervision of industrial processes. Several thousand industrial applications have been reported worldwide. Recently, the designers of the AI systems have begun to hybridize the intelligent techniques, expert systems, fuzzy logic and neural networks, to enhance the capability of the AI systems. Expert systems have proved to be ideal candidates especially for the control of mineral processes. As successful case projects, expert system based on on-line classification of the feed type is described in this paper. The essential feature of this expert system is the classification of different feed types and their distinct control strategies at the plant. In addition to the classification, the expert system has a database containing information about how to handle the determined feed type. This self-learning database scans historical process data to suggest the best treatment for the ore type under processing. The system has been tested in two concentrators, the Outokumpu Finnmines Oy, Hitura mine and Outokumpu Chrome Oy, Kemi mine. (author)

  20. Review of Brazilian activities related to the thorium fuel cycle and production of thorium compounds at IPEN-CNEN/SP

    International Nuclear Information System (INIS)

    Lainetti, Paulo E.O.; Freitas, Antonio A.; Mindrisz, Ana C.

    2013-01-01

    The Brazilian's interest in the nuclear utilization of thorium has started in the 50's as a consequence of the abundant occurrence of monazite sands. Since the sixties, IPEN-CNEN/SP has performed some developments related to the thorium fuel cycle. The production and purification of thorium compounds was carried out at IPEN for about 18 years and the main product was the thorium nitrate with high purity, having been produced over 170 metric tons of this material in the period, obtained through solvent extraction. The thorium nitrate was supplied to the domestic industry and used for gas portable lamps (Welsbach mantle). Although the thorium compounds produced have not been employed in the nuclear area, several studies were conducted. Therefore, those activities and the accumulated experience are of strategic importance, on one hand due to huge Brazilian thorium reserves, on the other hand by the resurgence of the interest of thorium for the Generation IV Advanced Reactors. This paper presents a review of the Brazilian research and development activities related to thorium technology. (author)