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Sample records for heavy water plant

  1. Modification of water treatment plant at Heavy Water Plant (Kota)

    International Nuclear Information System (INIS)

    Gajpati, C.R.; Shrivastava, C.S.; Shrivastava, D.C.; Shrivastava, J.; Vithal, G.K.; Bhowmick, A.

    2008-01-01

    Heavy Water Production by GS process viz. H 2 S - H 2 O bi-thermal exchange process requires a huge quantity of demineralized (DM) water as a source of deuterium. Since the deuterium recovery of GS process is only 18-19%, the water treatment plant (WTP) was designed and commissioned at Heavy Water Plant (Kota) to produce demineralized water at the rate of 680 m 3 /hr. The WTP was commissioned in 1980 and till 2005; the plant was producing DM water of required quality. It was having three streams of strong cation resin, atmospheric degasser and strong anion exchange resin with co-current regeneration. In 2001 a new concept of layered bed resin was developed and engineered for water treatment plant. The concept was attractive in terms of saving of chemicals and thus preservation of environment. Being an ISO 9000 and ISO 14000 plant, the modification of WTP was executed in 2005 during major turn around. After modification, a substantial amount of acid and alkali is saved

  2. Seismic re-evaluation of Heavy Water Plant, Kota

    International Nuclear Information System (INIS)

    Parulekar, Y.M.; Reddy, G.R.; Vaze, K.K.; Kushwaha, H.S.

    2003-10-01

    This report deals with seismic re-evaluation of Heavy Water Plant, Kota. Heavy Water Plant, Kota handles considerable amount of H 2 S gas, which is very toxic. During the original design stage as per IS 1893-1966 seismic coefficient for zone-I was zero. Therefore earthquake and its effects were not considered while designing the heavy water plant structures. However as per IS 1893 (1984) the seismic coefficient for zone-I is 0.01 g. Hence seismic re-evaluation of various structures of the heavy water plant is carried out. Analysis of the heavy water plant structures was carried out for self weight, equipment load and earthquake load. Pressure loading was also considered in case of H 2 S storage tanks. Soil structure interaction effect was considered in the analysis. The combined stresses in the structures due to earthquake and dead load were checked with the allowable stresses. (author)

  3. Overcoming technology - obsolescence: a case study in Heavy Water Plant

    International Nuclear Information System (INIS)

    Gupta, O.P.; Sonde, R.R.; Wechalekar, A.K.

    2002-01-01

    Ammonia based Heavy Water Plants in India are set up essentially in conjunction with fertiliser plants for the supply of feed synthesis gas. Earlier ammonia was being produced in fertiliser plants using high-pressure technology which was highly energy intensive. However with fast developments in the field of production of ammonia, fertiliser plants are switching over to low pressure technology. Ammonia based heavy water plants have to operate on pressures corresponding to that of fertiliser plants. Due to low pressures in production of ammonia, heavy water plants would also be required to operate at low pressures than the existing operating pressures. This problem was faced at Heavy Water Plant at Baroda where GSFC supplying synthesis gas switched over to low pressure technology making it imperative on the part of Heavy Water Board to carry out modification to the main plant for continued operation of Heavy Water Plant, Baroda. Anticipating similar problems due to production of ammonia at lower pressures in other fertiliser plants linked to existing Heavy Water Plants, it became necessary for HWB to develop water ammonia front end. The feed in such a case would be water instead of synthesis gas. This would enable HWB to dispense with dependence on fertiliser plants especially if grass-root ammonia based heavy water plants are to be set up. Incorporation of water ammonia front end would enable HWB to de link ammonia based heavy water plants with fertiliser plants. This paper discusses the advantage of de linking heavy water plant respective fertiliser plant by incorporating water ammonia front end and technical issues related to front end technology. A novel concept of ammonia absorption refrigeration (AAR) was considered for the process integration with the front end. The incorporation of AAR with water ammonia front-end configuration utilizes liquid ammonia refrigerant to generate refrigeration without additional energy input which otherwise would have been

  4. Heavy water physical verification in power plants

    International Nuclear Information System (INIS)

    Morsy, S.; Schuricht, V.; Beetle, T.; Szabo, E.

    1986-01-01

    This paper is a report on the Agency experience in verifying heavy water inventories in power plants. The safeguards objectives and goals for such activities are defined in the paper. The heavy water is stratified according to the flow within the power plant, including upgraders. A safeguards scheme based on a combination of records auditing, comparing records and reports, and physical verification has been developed. This scheme has elevated the status of heavy water safeguards to a level comparable to nuclear material safeguards in bulk facilities. It leads to attribute and variable verification of the heavy water inventory in the different system components and in the store. The verification methods include volume and weight determination, sampling and analysis, non-destructive assay (NDA), and criticality check. The analysis of the different measurement methods and their limits of accuracy are discussed in the paper

  5. Consequences of potential accidents in heavy water plants

    International Nuclear Information System (INIS)

    Croitoru, C.; Lazar, R.E.; Preda, I.A.; Dumitrescu, M.

    2002-01-01

    Heavy water plants achieve the primary isotopic concentration by H 2 O-H 2 S chemical exchange. In these plants are stored large quantities of hydrogen sulphide (high toxic, corrosive, flammable and explosive) maintained in process at relative high temperatures and pressures. It is required an assessment of risks associated with the potential accidents. The paper presents adopted model for quantitative consequences assessment in heavy water plants. Following five basic steps are used to identify the risks involved in plants operation: hazard identification, accident sequences development, H 2 S emissions calculus, dispersion analyses and consequences determination. A brief description of each step and some information from risk assessment for our heavy water pilot plant are provided. Accident magnitude, atmospheric conditions and population density in studied area were accounted for consequences calculus. (author)

  6. Tritium concentration in the heavy water upgrading plants

    International Nuclear Information System (INIS)

    Croitoru, C.; Pop, F.; Titescu, Gh.; Dumitrescu, M.; Ciortea, C.; Stefanescu, I.; Peculea, M.; Pitigoi, Gh.; Trancota, D. . E-mail of corresponding author: croitoru@icsi.ro; Croitoru, C.)

    2005-01-01

    In the course of time heavy water used in CANDU nuclear power plants, as moderator or coolant, degrades, as a result of its impurification with light water and tritium. Concentration diminution below 99.8% mol for moderator and 99.75% mol for coolant causes an inefficient functioning of CANDU reactor. By isotopic distillation, light water is removed. Simultaneously tritium concentration takes place. The heavy water upgrading plant from Cernavoda is an isotopic separation cascade with two stages. The paper presents, for this plant, a theoretical study of the tritium concentration. (author)

  7. The heavy water production plant at Arroyito, Argentina

    International Nuclear Information System (INIS)

    Ecabert, R.

    1984-01-01

    The author describes the construction of an industrial heavy water production plant (Planta Industrial de Agua Pesada, PIAP) in Argentina. The heavy water enrichment is based on a hydrogen/ammonia isotope exchange. (Auth.)

  8. Improved method of degassing of feed water at Heavy Water Plant, Kota

    International Nuclear Information System (INIS)

    Krishnan, G.K.; Agrawal, A.K.

    1994-01-01

    Heavy Water Plant (Kota) processes 450 MT/hr of feed water as the source of deuterium using water/hydrogen sulphide exchange process for the production of heavy water. Plant design has limited the ingress of dissolved oxygen in feed water to 0.2 ppm. However, even this low limit on dissolved oxygen has been found unacceptable during plant operation as over an operational period of 3-4 years accumulation of sulphur due to oxidation of hydrogen sulphide on exchange tower trays poses major operational problems. This paper discusses the results of nitrogen injection used for reducing the ingress of dissolved oxygen in the feed water system of the plant. (author)

  9. Improved method of degassing of feed water at Heavy Water Plant, Kota

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, G K; Agrawal, A K [Heavy Water Plant, Kota (India)

    1994-06-01

    Heavy Water Plant (Kota) processes 450 MT/hr of feed water as the source of deuterium using water/hydrogen sulphide exchange process for the production of heavy water. Plant design has limited the ingress of dissolved oxygen in feed water to 0.2 ppm. However, even this low limit on dissolved oxygen has been found unacceptable during plant operation as over an operational period of 3-4 years accumulation of sulphur due to oxidation of hydrogen sulphide on exchange tower trays poses major operational problems. This paper discusses the results of nitrogen injection used for reducing the ingress of dissolved oxygen in the feed water system of the plant. (author). 1 fig.

  10. Water conservation by 3 R's - case histories of Heavy Water Plants

    International Nuclear Information System (INIS)

    Agarwal, A.K.; Hiremath, S.C.

    2005-01-01

    The basics of water conservation revolve around three R's of Reduce, Recycle, and Reuse. The Heavy Water Plants are an excellent example of water savings, and these case studies will be of interest to the chemical industry. The issues involved with water conservation and re-use in different Heavy Water Plants are of different nature. In H 2 S-H 2 O process plants the water consumption has been substantially decreased as compared to the design water needs. To quote the figures HWP (Kota) was designed to consume 2280 m 3 /hr water, which included 453 m 3 /hr water as feed for deuterium extraction. Today the plant operates with only 1250 m 3 /hr water while processing 500 m 3 /hr feed; and is headed to decrease the total water consumption to 700 m 3 /hr. Similarly at HWP (Manuguru) the design had provided 5600 m 3 /hr water consumption, which is today operating with only 1750 m 3 /hr and poised to operate with 1600 m 3 /hr. The issues of water conservation in Ammonia Hydrogen exchange plants have an additional dimension since water losses mean direct loss of heavy water production. In adjoining ammonia plants deuterium shifts to steam in the reformer and shift converter, and this excess steam is condensed as rich condensate. It becomes incumbent on the fertilizer plant to maintain a tight discipline for conserving and re-using the rich condensate so that deuterium concentration in the synthesis gas is maintained. Efforts are also underway to utilize rich condensate of GSFC in the newly developed technology of water ammonia exchange at HWP (Baroda) and we are targeting 20% production gains by implementation of this scheme and with no increase in the pollution load. These case histories will be of interest to Chemical Process Industry. (author)

  11. Radiation safety experience in upgrading 2-5% heavy water wastes at Heavy Water Plant, Nangal (Preprint No. SA-7)

    International Nuclear Information System (INIS)

    Sadhukhan, H.K.; Behl, D.; Ramraj; Iyengar, T.S.; Sadarangani, S.H.; Vaze, P.K.; Soman, S.D.

    1989-04-01

    This paper describes the radiological safety experience in upgrading 2-5% heavy water wastes at Heavy Water Plant at Nangal at the third stage electrolysers. The feed water concentrations at the third stage electrolyer was determined after a safety analysis study and pilot plant experiment, which gave the optimal concentrations of 1 to 1.5 mCi (3.7 to 5.5 x 10 7 Bq) per litre per minute feed from a submerged SS tank containing 2-5% heavy water wastes. This process not only yielded an efficient recovery of reactor grade heavy water but contained the tritium activity in the third stage electrolysers and in the final product viz., heavy water. The tritium concentrations were continuously monitore d by liquid scintillation counting method at all the three stages of electrolysis plant, the distillation plant, the heavy water filling rooms, the drains, the ambient air, the product fertilizer (calcium ammonia nitrate) and the Sutlej River and found to be well within the safety limits set for general public at large. The HD and D 2 process streams in the palnt were monitored using fill-in type of ionization chambers designed for the purpose, which served a D 2 inventory check as well. There was no internal exposure to any personnel during the entire period of programme. (author). 2 tabs

  12. Assets optimization at Heavy Water Plants

    International Nuclear Information System (INIS)

    Hiremath, S.C.

    2006-01-01

    In the world where the fittest can only survive, manufacturing and production enterprises are under intense pressure to achieve maximum efficiency in each and every field related to the ultimate production of plant. The winners will be those that use their assets, i.e men, material, machinery and money most effectively. The objective is to optimize the utilization of all plant assets-from entire process lines to individual pressure vessels, piping, process machinery, and vital machine components. Assets of Heavy Water Plants mainly consist of Civil Structures, Equipment and Systems (Mechanical, Electrical) and Resources like Water, Energy and Environment

  13. Energy conservation and management strategies in Heavy Water Plants

    International Nuclear Information System (INIS)

    Kamath, H.S.

    2002-01-01

    In the competitive industrial environment it is essential that cost of the product is kept at the minimum possible. Energy conservation is an important aspect in achieving this as energy is one of the key recourses for growth and survival of industry. The process of heavy water production being very complex and energy intensive, Heavy Water board has given a focussed attention for initiating various measures for reducing the specific energy consumption in all the plants. The initiative resulted in substantial reduction in specific energy consumption and brought in savings in cost. The cumulative reduction of specific energy consumption has been over 30% over the last seven years and the total savings for the last three years on account of the same has been about Rs. 190 crore. The paper describes the strategies adopted in the heavy water plants for effecting the above achievements. The paper covers the details of some of the energy saving schemes carried out at different heavy water plants through case studies. The case studies of schemes implemented at HWPs are general in nature and is applicable for any other industry. The case studies cover the modifications with re-optimisation of the process parameters, improvements effected in utility units like refrigeration and cooling water systems, improvements in captive power plant cycle and improved recycle scheme for water leading to reduced consumptions. The paper also mentions the innovative ammonia absorption refrigeration with improved coefficient of performance and HWB's efforts in development of the system as an integrated unit of the ammonia water deuterium exchange process for heavy water production. HWB also has taken up R and D on various other schemes for improvements in energy consumption for future activities covering utilisation of low grade energy for generation of refrigeration. (author)

  14. Possibilities for reorientation the activity of heavy water plants

    International Nuclear Information System (INIS)

    Pop, F.; Croitoru, C.; Titescu, Gh.; Stefanescu, I.; Hodor, I.; Cuna, S. . E-mail of corresponding author: pop.floarea@icsi.ro; Pop, F.)

    2005-01-01

    In Romania heavy water is produced by H 2 O-H 2 S chemical exchange (GS process) and by water distillation, simultaneously working two lines. The distillation plants have high separation capacity, a distillation line being able to concentrate water from two GS lines. The paper presents data regarding possibilities to use one distillation line for oxygen 18 production, as pre-concentrates or finite products. Using a simulation program it was calculated oxygen 18 concentration in heavy water produced, maximum 18 O concentration of pre-concentrate obtained on distillation line and the separation cascade dimensions for obtain 95% 18 O, with first and second stage having same dimensions like a distillation plant from Romanian heavy water factory. Oxygen-18 separation factor is much lower than deuterium separation factor. For this reason, oxygen-18 is a very expensive product. (author)

  15. Possibilities for reorientation of activity in Heavy Water Plants

    International Nuclear Information System (INIS)

    Pop, F.; Croitoru, C.; Titescu, Gh.; Stefanescu, I.; Hodor, I.; Cuna, S.

    2004-01-01

    In Romania heavy water is produced by H 2 O-H 2 S chemical exchange (GS process) and by water distillation, in two lines working simultaneously. The distillation plants have high separation capacity, a distillation line being able to concentrate water from two GS lines. The paper presents data regarding possibilities to use one distillation line for oxygen - 18 production, as pre-concentrates or finite products. A simulation program was used to calculate the oxygen - 18 concentration in the heavy water produced, maximum 18 O concentration of pre-concentrate obtained on distillation line and the separation cascade sizes to obtain 95% 18 O, with first and second stage having the same sizes like the distillation plant from the Romanian heavy water factory. Oxygen-18 separation factor is much lower than deuterium separation factor. For this reason, oxygen-18 is a very expensive product. (authors)

  16. Safety system in a heavy water detritiation plant

    International Nuclear Information System (INIS)

    Balteanu, O.; Stefan, I.; Retevoi, C.

    2003-01-01

    In a CANDU 6 type reactor a quantity of 55·10 15 Bq/year of tritium is generated, 95% being in the D 2 O moderator which can achieve a radioactivity of 2.5-3.5·10 12 Bq/kg. Tritium in heavy water contributes with 30-50% to the doses received by operation personnel and up to 20% to the radioactivity released in the environment. The large quantity of heavy water used in this type of reactors (500 tones) make storage very difficult, especially for environment. The extraction of tritium from tritiated heavy water of CANDU reactors solve the following problems: the radiation level in the operation area, the costs of maintenance and repair reduction due to reduction of personnel protection measures, the increase of NPP utilisation factor by shutdown time reduction for maintenance and repair, use the extracted tritium for fusion reactors and not for the last, lower costs and risk for storage heavy water waste. Heavy water detritiation methods, which currently are used in the industrial or experimental plant, are based on catalytic isotope exchange or electrolysis followed cryogenic distillation or permeation. The technology developed at Institute of Cryogenics and Isotope Separation is based upon catalytic exchange between tritiated water and deuterium, followed by cryogenic distillation of hydrogen isotopes. The nature of the fluids that are processed in detritiation requires the operation of the plant in safety conditions. The paper presents the safety system solution chose in order to solve this task, as well as a simulation of an incident and safety system response. The application software is using LabView platform that is specialised on control and factory automation applications. (author)

  17. Commissioning performance activities of Heavy Water Plant (Hazira) (Paper No. 1.4)

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Heavy Water Plant, Hazira is the fourth in the line of plants based on monothermal NH 3 -H 2 exchange process. The experience gained during operation of other heavy water plants is reflected in the construction, commissioning and operation of HWP, Hazira. This paper aims at outlining the strategy adopted for both commissioning and operation. (author)

  18. Effect of operation of ammonia plants on the performance of heavy water plants (Paper No. 2.7)

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Heavy Water Plant, Hazira has two streams and each stream is designed to process 48 MT/hr of synthesis gas to produce the rated quantity of heavy water. However in actual practice, it is observed that actual gas composition is different from the above due to various reasons. This article describes effects of various parameters of ammonia plant on the functioning of heavy water plants, such as concentration of D/D+H in synthesis gas, concentration of hydrogen in synthesis gas, concentration of inerts in synthesis gas, pressure of synthesis gas, on stream days of ammonia plant, and concentration of impurities like CO/CO 2 in synthesis gas. (author). 2 figs

  19. Embalse nuclear power plant and heavy water valuation

    International Nuclear Information System (INIS)

    Martin, Daniel E.

    2008-01-01

    The author describes the nuclear power plant characteristics, the building work, the heavy water valuation criteria and the reasons why he considers that any capital good can be valued by the cash-flow method. The Embalse nuclear power plant replacement value is of U$S 1.593.538.000. (author) [es

  20. Extending the product variety at ROMAG-PROD Heavy Water Plant

    International Nuclear Information System (INIS)

    Preda, M.; Patrascu, M.; Achimescu, D.; Stroia, A.

    2004-01-01

    Full text: Having in mind that the prospects of operating the ROMAG-PROD Heavy Water Plant are conditioned by both the heavy water market demand and the wear of the equipment which is exposed to hydrogen sulfide-induced corrosion, some possibilities were considered to extend the assortment of products, the production of which could ensure the plant's operation on long term. The proposals here refer to promoting the efficient production of oxygen-isotope-based products which would optimize maximally the exploit of available raw materials, supply and utilities of the ROMAG compound. The market manifests a significant demand of water enriched in the 18 O isotope up to 95-97% purity that is used in Positron Emission Tomography (PET). This oxygen isotope is also used as a labelling agent in studies of reaction mechanisms and paleo-climatologic studies as well. Some research evidenced the superconducting properties of some oxygen compounds containing the 18 O isotope. The isotope 17 O has applications in Nuclear Magnetic Resonance (NMR) as being the sole oxygen isotope endowed with a nuclear magnetic moment. On the other hand, it was found that although the 16 O isotope has a natural abundance of 99.8%, applications exist that require the absolute purity of this isotope i.e. the elimination of the other oxygen isotopes as is the case of fission reactors with Plutonium dioxide as nuclear fuel. The methods applied on industrial scale for enriching the oxygen isotopes are based on distillation of some oxygen compounds such as water and nitrogen monoxide. The possibility of a supplementary distillation of the heavy water at a distillation line of ROMAG-PROD Heavy Water Plant was considered in order to enrich the heavy water in the 17 O and 18 O isotopes up to an upper limit of 2-5% for 18 O. Obtaining the heavy isotopes of oxygen by distillation of heavy water is characterized by several aspects as the following ones: a high specific consumption of steam due to both the low

  1. Consequence of potential accidents in heavy water plants

    International Nuclear Information System (INIS)

    Croitoru, C.; Lazar, R.E.; Preda, I.A.; Dumitrescu, M.

    1998-01-01

    Heavy water plants realize the primary isotopic concentrations of water using H 2 O-H 2 S chemical exchange and they are chemical plants. As these plants are handling and spreading large quantities of hydrogen sulphide (high toxic, corrosive, flammable and explosive as) maintained in the process at relative high temperatures and pressures, it is required an assessing of risks associated with the potential accidents. The H 2 S released in atmosphere as a result of an accident will have negative consequences to property, population and environment. This paper presents a model of consequences quantitative assessment and its outcome for the most dangerous accident in heavy water plants. Several states of the art risk based methods were modified and linked together to form a proper model for this analyse. Five basic steps to identify the risks involved in operating the plants are followed: hazard identification, accident sequence development, H 2 S emissions calculus, dispersion analyses and consequences determination. A brief description of each step and some information of analysis results are provided. The accident proportions, the atmospheric conditions and the population density in the respective area were accounted for consequences calculus. The specific results of the consequences analysis allow to develop the plant's operating safety requirements so that the risk remain at an acceptable level. (authors)

  2. Features in ammonia plant for maximising heavy water production (Paper No. 2.10)

    International Nuclear Information System (INIS)

    Tangri, N.N.; Singh, R.J.; Mukherjee, P.K.; Mishra, B.N.

    1992-01-01

    Whenever an ammonia plant is linked with heavy water production, a system should be foreseen in the design stage itself for total conservation of D 2 in synthesis gas and zero D 2 loss. The process should ensure recycle of D 2 rich condensate within the front end. This alone would be the single most important factor for improving heavy water production rate. The synthesis loop pressure should be chosen keeping in view the interest of heavy water plant (HWP). With vast experience in engineering NH 3 and HWP plants, it is possible to integrate HWP requirements at the design stage itself. (author)

  3. Environmental health scoping study at Bruce Heavy Water Plant

    International Nuclear Information System (INIS)

    Prior, M.; Mostrom, M.; Coppock, R.; Florence, Z.

    1995-10-01

    There are concerns that hydrogen sulfide released from the Heavy Water Plant near Kincardine, Ontario may be the cause of the mortalities and morbidities observed in a nearby flock of sheep. The Philosopher's Wool sheep farm is about four kilometres south-southeast of the Bruce Heavy Water Plant. Ontario Hydro, the owner and operator of the Bruce Heavy Water Plant, claims that hydrogen sulphide emissions from the Bruce Heavy Water Plant are within regulatory limits and well below levels that cause harm. Accordingly, the Atomic Energy Control Board commissioned the Alberta Environmental Centre, Alberta Department of Environmental Protection, to develop a scoping study for this environmental health issue. The first objective was to describe a field investigation model to define clearly the environmental health and operation of the sheep farm. The second objective was to describe possible exposure patterns and develop a holistic environmental pathway model. If appropriate, the third study objective was to describe animal models of the actual situation to elucidate specific aspects of the environmental health concerns. It was not the objective of this report to provide a definitive answer to the present environmental health issue. Ontario Hydro provided data to the Alberta Environmental Centre, as di the sheep farmer, the attending veterinarian, the University of Guelph study team, and the Atomic Energy Control Board. A six-tiered strategy of sequential evaluations of the ovine health problem is based on the multiple-response paradigm. It assumes the observed ovine health results are the result of multiple effector events. Each tier constitutes a separate, but inter-related, study. Sequential evaluation and feedback of each tier allow sound scientific judgements and efficient use of resources. (author). 59 refs., 11 tabs., 22 figs

  4. Improvements done at Heavy Water Plant (Manuguru) to increase the standards of environmental protection

    International Nuclear Information System (INIS)

    Rama Rao, V.V.S.; Gupta, R.V.; Pandey, B.L.

    1997-01-01

    The Heavy Water Plant at Manuguru is designed to produce 185 MTY of nuclear grade heavy water based on bithermal H 2 S-H 2 O exchange process and handles large inventory of H 2 S gas (about 400 MT). As H 2 S gas is very toxic, corrosive and hazardous in nature, extreme care has been taken in the design of plant, selection of equipment and materials adhering to stringent fabrication procedures and codes to ensure the production of heavy water in a safe manner. This paper highlights the improvements done at Heavy Water Plant (Manuguru) to increase the standards of environmental protection. The safety assessment of a hazardous plant is a continuous process. Apart from the extreme care taken in the design, construction, commissioning and operation of the plant, review of each and every safety related unusual occurrence by various levels of review committees as stipulated and speedy implementation of the recommendations goes in a long way in increasing the standards of environmental protection

  5. Cost effective water treatment program in Heavy Water Plant (Manuguru)

    International Nuclear Information System (INIS)

    Mohapatra, C.; Prasada Rao, G.

    2002-01-01

    Water treatment technology is in a state of continuous evolution. The increasing urgency to conserve water and reduce pollution has in recent years produced an enormous demand for new chemical treatment programs and technologies. Heavy water plant (Manuguru) uses water as raw material (about 3000 m 3 /hr) and its treatment and management has benefited the plant in a significant way. It is a fact that if the water treatment is not proper, it can result in deposit formation and corrosion of metals, which can finally leads to production losses. Therefore, before selecting treatment program, complying w.r.t. quality requirements, safety and pollution aspects cost effectiveness shall be examined. The areas where significant benefits are derived, are raw water treatment using polyelectrolyte instead of inorganic coagulant (alum), change over of regenerant of cation exchangers from hydrochloric acid to sulfuric acid and in-house development of cooling water treatment formulation. The advantages and cost effectiveness of these treatments are discussed in detail. Further these treatments has helped the plant in achieving zero discharge and indirectly increased cost reduction of final product (heavy water); the dosage of 3 ppm of polyelectrolyte can replace 90 ppm alum at turbidity level of 300 NTU of raw water which has resulted in cost saving of Rs. 15-20 lakhs in a year beside other advantages; the change over of regenerant from HCl to H 2 SO 4 will result in cost saving of at least Rs.1.4 crore a year besides other advantages; the change over to proprietary formulation to in-house formulation in cooling water treatment has resulted in a saving about Rs.11 lakhs a year. To achieve the above objectives in a sustainable way the performance results are being monitored. (author)

  6. Production of heavy water in India

    International Nuclear Information System (INIS)

    Deshpande, P.G.; Bimbhat, K.S.; Bhargava, R.K.

    India's first heavy water plant, using electrolysis of water followed by liquid hydrogen distillation, has been operating in association with a fertilizer plant at Nangal since 1962. A dual-temperature process plant at Kota uses heat from the Rajasthan Atomic Power Station. The heavy water plants at Baroda and Tuticorin use ammonia-hydrogen exchange and are integrated with fertilizer ammonia plants. Choice of a particular process for heavy water production depends upon local conditions as well as the extent of the heavy water requirement

  7. AECB staff annual report of Bruce Heavy Water Plant operation for the year 1991

    International Nuclear Information System (INIS)

    1992-11-01

    Bruce Heavy Water Plant operation was acceptably safe in 1991. There were no breaches of any of the regulations issued under the authority of the Atomic Energy Control Act. There was one violation of the operating licence. For one hour on October 30, 1991, water leaving the plant contained more hydrogen sulphide than Ontario regulations allow. There was no threat to public health or safety or harm to the environment as a result of this violation. One worker was overcome by hydrogen sulphide. The worker did not lose consciousness, but had the symptoms of H 2 S poisoning. Ontario Hydro took actions to increase awareness of the Operating Policy and Principles at Bruce Heavy Water Plant during 1991. All personnel attended a training course, and Ontario Hydro is reviewing all Bruce Heavy Water Plant documentation to ensure it is consistent with the Operating Policies and Principles. Ontario Hydro met 13 of 15 safety-related system availability targets. The AECB is satisfied appropriate action is being taken to improve the performance of the other two systems. Ontario Hydro continued to put heavy emphasis on safety training; however, they did not meet some of their other training targets. Ontario Hydro completed all of the planned emergency exercises at Bruce Heavy Water Plant in 1991. (Author)

  8. The importance of the reliability study for the safety operation of chemical plants. Application in heavy water plants

    International Nuclear Information System (INIS)

    Dumitrescu, Maria; Lazar, Roxana Elena; Preda, Irina Aida; Stefanescu, Ioan

    1999-01-01

    Heavy water production in Romania is based on H 2 O-H 2 S isotopic exchange process followed by vacuum isotopic distillation. The heavy water plant are complex chemical systems, characterized by an ensemble of static and dynamic equipment, AMC components, enclosures. Such equipment must have a high degree of reliability, a maximum safety in technological operation and a high availability index. Safety, reliable and economical operation heavy water plants need to maintain the systems and the components at adequate levels of reliability. The paper is a synthesis of the qualitative and quantitative assessment reliability studies for heavy water plants. The operation analysis on subsystems, each subsystems being a well-defined unit, is required by the plant complexity. For each component the reliability indicators were estimated by parametric and non-parametric methods based on the plant operation data. Also, the reliability qualitative and quantitative assessment was done using the fault tree technique. For the dual temperature isotopic exchange plants the results indicate an increase of the MTBF after the first years of operation, illustrating both the operation experience increasing and maintenance improvement. Also a high degree of availability was illustrated by the reliability studies of the vacuum distillation plant. The establishment of the reliability characteristics for heavy water plant represents an important step, a guide for highlighting the elements and process liable to failure being at the same time a planning modality to correlate the control times with the maintenance operations. This is the way to minimise maintenance, control and costs. The main purpose of the reliability study was the safety increase of the plant operation and the support for decision making. (authors)

  9. Dynamic modelling of Industrial Heavy Water Plant

    International Nuclear Information System (INIS)

    Teruel, F.E.

    1997-01-01

    The dynamic behavior of the isotopic enrichment unites of the Industrial Heavy Water Plant, located in Arroyito, Neuquen, Argentina, was modeled and simulated in the present work. Dynamic models of the chemical and isotopic interchange processes existent in the plant, were developed. This served as a base to obtain representative models of the different unit and control systems. The developed models were represented in a modular code for each unit. Each simulator consists of approximately one hundred non-linear-first-order differential equations and some other algebraic equation, which are time resolved by the code. The different simulators allow to change a big number of boundary conditions and the control systems set point for each simulation, so that the program become very versatile. The output of the code allows to see the evolution through time of the variables of interest. An interface which facilitates the use of the first enrichment stage simulator was developed. This interface allows an easy access to generate wished events during the simulation and includes the possibility to plot evolution of the variables involved. The obtained results agree with the expected tendencies. The calculated nominal steady state matches by the manufacturer. The different steady states obtained, agree with previous works. The times and tendencies involved in the transients generated by the program, are in good agreement with the experience obtained at the plant. Based in the obtained results, it is concluded that the characteristic times of the plant are determined by the masses involved in the process. Different characteristics in the system dynamic behavior were generated with the different simulators, and were validated by plant personnel. This work allowed to understand the different process involved in the heavy water manufacture, and to develop a very useful tool for the personnel of the plant. (author). 14 refs., figs., tabs. plant. (author). 14 refs., figs., tabs

  10. Effective integration between heavy water plant and fertilizer plant for higher production of heavy water (D2O) (Preprint No. PD-10)

    International Nuclear Information System (INIS)

    Periakaruppan, M.; Gupta, S.K.; Bhowmick, S.C.

    1989-04-01

    For smooth and efficient running of heavy water plants linked with fertilize r plants, it is necessary that certain factors must be taken into consideration right from the design stage of a fertilizer plant. These factors are: (1)preventing loss in D 2 concentration in syn gas, (2)keeping the level of CO 2 and CO in syn gas below 1 ppm, (3)operating the ammonia plant at highest pressure and (4)keeping the feed gas ammonia supply available without any interruption. Incorporation of these factors in the design is discussed. (M.G.B. )

  11. Seismic re-evaluation of piping systems of heavy water plant, Kota

    CERN Document Server

    Mishra, R; Soni, R S; Venkat-Raj, V

    2002-01-01

    Heavy Water Plant, Kota is the first indigenous heavy water plant built in India. The plant started operation in the year 1985 and it is approaching the completion of its originally stipulated design life. In view of the excellent record of plant operation for the past so many years, it has been planned to carry out various exercises for the life extension of the plant. In the first stage, evaluation of operation stresses was carried out for the process critical piping layouts and equipment, which are connected with 25 process critical nozzle locations, identified based on past history of the plant performance. Fatigue life evaluation has been carried out to fmd out the Cumulative Usage Factor, which helps in arriving at a decision regarding the life extension of the plant. The results of these exercises have been already reported separately vide BARC/200I /E/O04. In the second stage, seismic reevaluation of the plant has been carried out to assess its ability to maintain its integ:rity in case of a seismic e...

  12. Valuation of Embalse Nuclear Power Plant and of heavy water

    International Nuclear Information System (INIS)

    Martin, D.E.

    2008-01-01

    The author describes the Nuclear Power Plant characteristics, the building work, the heavy water valuation criteria and the reasons why he considers that any capital good can be valuated by means of cash-flow. The value of replacement of Embalse Nuclear Power Plant is of U$S 1.593.538.000 (authors) [es

  13. National symposium on commissioning and operating experiences in heavy water plants and associated chemical industries [Preprint volume

    International Nuclear Information System (INIS)

    1992-02-01

    A symposium on commissioning and operating experiences in heavy water plants and associated chemical industries (SCOPEX-92) was organised to share the experience and exchange the ideas among plant operators, designers, consultants and vendors in the areas of operation, commissioning and equipment performance. This pre-print volume has been brought out as an integrated source of information on commissioning and operation of heavy water plants. The following aspects of heavy water plants are covered: commissioning and operation, instrumentation and control, and safety and environment. (V.R.)

  14. Operating experiences on ammonia water exchange system at Heavy Water Plant, Talcher (paper No. 6.12)

    International Nuclear Information System (INIS)

    Venkat Ram, D.; Sharma, A.K.

    1992-01-01

    The Heavy Water Plant at Talcher employs bithermal ammonia hydrogen exchange process for the production of heavy water. The paper describes about the existing ammonia water exchange column, its start-up, operating experience and the problems encountered in operation of the column. The operating experiences gained and the data collected over the last few years can be utilised for design and operation of new ammonia water exchange column. (V.R). 2 figs

  15. Deuterium concentration deterioration in feed synthesis gas from ammonia plant to heavy water plant (Preprint No. ED-5)

    International Nuclear Information System (INIS)

    Sah, A.K.

    1989-04-01

    Heavy Water Plant (Thal) is designed for 110 T/ Year capacity (55 T/Year each stream), with inlet deuterium concentration of feed synthesis gas at 115 ppm and depleted to 15 ppm. During first start up of plant the inlet concentration to feed synthesis gas was about 97 ppm. At that time the rich condensate recirculation was not there. To make the effective recirculation of deuterium rich condensate and minimum posssible losses some modifications were carried out in ammonia plant. Major ones are: (i)Demineralised (DM) water export for heavy water plant and urea plant which was having deuterium rich DM water connection was connected with DM water of urea plant which is not rich in deuterium, (ii)Sample cooler pump suction was connected with raw water, (iii)Ammonia plant line No.II condensate stripper was rectified during annual shut down to avoid excessive steam venting from its top and other draining, and (iv)Stripper condensate directly connected to make up water bypassing open settler to avoid evaporation and diffusion losses. With these modifications the deuterium concentration in feed synthesis gas improved to about 105 ppm. To improve it to 115 ppm, further modifications are suggested. (author). 5 figs

  16. Fluoride content in water in and around heavy water plant Manuguru colony

    International Nuclear Information System (INIS)

    Mohapatra, C.; Dubey, S.K.; Reddy, A.R.; Ravi Kumar, T.S.P.; Selvaraj, S.

    1996-01-01

    Fluoride concentration in water used for human consumption has significant importance with respect to its toxic effects. Hence there was a need for analysing fluoride concentration in drinking water primarily used at Heavy water Plant, Manuguru (HWP (M)) colony and its nearby villages. We found that at HWP (M) colony there is not much variation in the fluoride concentration. However, nearby villages are having wide variation from 0.79 to 5.1 ppm. (author). 5 refs., 1 tab

  17. Heavy metal and radioactivity measurements in fish, water, plants and soils in tin-mining pool

    International Nuclear Information System (INIS)

    Muhammad Samudi Yasir; Norlaili Ahmad Kabir; Redzuwan Yahaya; Amran Abdul Majid

    2008-01-01

    Malaysia aggressively reclaimed most of their disused tin-mining pool especially for agricultural activities, freshwater fish farming area, recreational area, houses area and even as an industrial area. Past mining activities might induced the concentration of naturally occurring radionuclide (NORM) and heavy metal at the disused tin-mining pool ecosystem. A study has been conducted on the status of heavy metal (Hf, Zr, Mn, Cu, Zn, As, Cd, Sn, Sb, Ba, Hg and Pb) concentration and naturally occurring radionuclide activity in fish, water, plants and sediments at three different disused tin-mining pool near by Sepang and Puchong, Selangor Darul Ehsan. Sample of fish, water, plant and sediment being analyze using ICP-MS. The concentrations of heavy metal in sediment and plant are higher than its concentrations in fish and followed by water. The highest concentration of heavy metal in sediment and water is barium, whereas the highest concentration of heavy metal in fish and plant is zinc and manganese. The result also showed that only mercury level in fish collected in second disused tin-mining pool (0.53 ± 0.20 mg/ kg) is exceed the maximum limit (0.5 mg/ kg) prescribe by the Malaysian Food Act (Act 281). The activity of U-238 and Th-232 in sediment was found to be relatively higher than its activity in fish, plant or water (30.76 ± 2.71 to 35.34 ± 0.27 Bq/ kg) and (9.37 ± 2.30 - 18.86 ± 2.60 Bq/ kg). The determination of K-40 activity showed that it is highly contained in plant and fish than in sediment or water. (author)

  18. A painless approach to use distributed digital-control system for Heavy Water Plant- Tuticorin

    International Nuclear Information System (INIS)

    Potti, V.S.; Krishnan, S.; Rao, V.C.; Lamba, D.S.

    1994-01-01

    Heavy Water Plant (Tuticorin) production is based on mono thermal process of ammonia-hydrogen exchange and is connected with a 1100 tons per day capacity ammonia plant of M/s Southern Petrochemical Industries Limited for getting its feed. The deuterium concentration in the syngas (N 2 + 3H 2 ) is extracted through ammonia-hydrogen exchange process and finally burnt with air in the final product unit to get heavy water. The depleted syngas is sent back to M/s SPIC's synthesis unit. The purpose of this paper is to highlight the instrumentation requirements of heavy water production, problems encountered in use of DDCS along with remedial action taken for the back up facility. (author)

  19. Radionuclides and heavy metal uptake by lolium italicum plant as affected by saline water irrigation

    International Nuclear Information System (INIS)

    Ramadan, A.A.; Aly, A.I.; Helal, M.H.

    2001-01-01

    The use of saline waters to grow crops on increasingly metal polluted soils is becoming a common practice in the arid regions. Nevertheless, the effects of soil and water salinity on radionuclides and heavy metal fluxes in polluted areas are not well understood. The aim of this study was to evaluate in pot experiments the plant uptake of cesium-137, Co-60, Mn-54, Zinc, cadmium and copper from a polluted alluvial aridisol as affected by salt water irrigation. Fertilized soil material was planted in pots with L. Italicum for 18 weeks under greenhouse conditions. The plants were irrigated either with water or with salt solution of variable variable Na/Ca ratio and harvested every 5-7 weeks. In addition to elemental analysis of plants and soil extracts root length was determined by a gridline intersect method and the viable part of the roots was estimated by a root protein inex. Saline (Na) water irrigation increased cobalt-60, manganese-54 and heavy metal solubility in soil, reduced root viability and enhanced the uptake of Co-60, Mn-54, Cd, Cu, Zn and Na by L.italicum and reduced the uptake of Cs-137. Ca counteracted these effects partly. The presented results demonstrated a dual effect of salinity on radiouclides and heavy metal availability to plants and suggest a relationship between root mortality and the enhanced Co-60, Mn-54, and heavy metake ny salt stressed plants

  20. A painless approach to use distributed digital-control system for Heavy Water Plant- Tuticorin

    Energy Technology Data Exchange (ETDEWEB)

    Potti, V S; Krishnan, S; Rao, V C; Lamba, D S [Heavy Water Project, Tuticorin (India)

    1994-06-01

    Heavy Water Plant (Tuticorin) production is based on mono thermal process of ammonia-hydrogen exchange and is connected with a 1100 tons per day capacity ammonia plant of M/s Southern Petrochemical Industries Limited for getting its feed. The deuterium concentration in the syngas (N{sub 2} + 3H{sub 2}) is extracted through ammonia-hydrogen exchange process and finally burnt with air in the final product unit to get heavy water. The depleted syngas is sent back to M/s SPIC`s synthesis unit. The purpose of this paper is to highlight the instrumentation requirements of heavy water production, problems encountered in use of DDCS along with remedial action taken for the back up facility. (author). 3 refs., 2 figs.

  1. Effect of design and operation of modern ammonia plants on the performance of integrated heavy water plants (Paper No. 2.1)

    International Nuclear Information System (INIS)

    Kumar, Manoj; Haldar, T.K.; Gupta, S.K.; Ramamurty, C.B.

    1992-01-01

    The heavy water plant being parasitic in nature, its design, operation and performance is affected to a great extent by the design, performance and operation of the ammonia plant. Some of the factors which affect the performance of heavy water plant such as on-stream hours and capacity utilisation of the ammonia plant, deuterium concentration (D/D+H) in feed synthesis gas, operating pressure of synthesis loop of ammonia plant, composition of feed synthesis gas, and level of oxygenated impurities in feed synthesis gas are described in this paper. (author). 3 tabs., 4 figs

  2. Meta-Analysis of the Copper, Zinc, and Cadmium Absorption Capacities of Aquatic Plants in Heavy Metal-Polluted Water.

    Science.gov (United States)

    Li, Jing; Yu, Haixin; Luan, Yaning

    2015-11-26

    The use of aquatic plants for phytoremediation is an important method for restoring polluted ecosystems. We sought to analyze the capacity of different aquatic plant species to absorb heavy metals and to summarize available relevant scientific data on this topic. We present a meta-analysis of Cu, Zn, and Cd absorption capacities of aquatic plants to provide a scientific basis for the selection of aquatic plants suitable for remediation of heavy-metal pollution. Plants from the Gramineae, Pontederiaceae, Ceratophyllaceae, Typhaceae and Haloragaceae showed relatively strong abilities to absorb these metals. The ability of a particular plant species to absorb a given metal was strongly correlated with its ability to absorb the other metals. However, the absorption abilities varied with the plant organ, with the following trend: roots > stems > leaves. The pH of the water and the life habits of aquatic plants (submerged and emerged) also affect the plant's ability to absorb elements. Acidic water aids the uptake of heavy metals by plants. The correlation observed between element concentrations in plants with different aquatic life habits suggested that the enrichment mechanism is related to the surface area of the plant exposed to water. We argue that this meta-analysis would aid the selection of aquatic plants suitable for heavy-metal absorption from polluted waters.

  3. Halden Boiling Water Reactor. Plant Performance and Heavy-Water Management

    Energy Technology Data Exchange (ETDEWEB)

    Aas, S.; Jamne, E.; Wullum, T.; Fjellestad, K. [Institutt for Atomenergi, OECD Halden Reactor Project, Halden (Norway)

    1968-04-15

    The Halden boiling heavy-water reactor, designed and built by the Norwegian Institutt for Atomenergi, has since June 1958 been operated as an international project. On its second charge the reactor was operated at power levels up to 25 MW and most of the time at a pressure of 28.5 kg/cm{sup 2}. During the period from July 1964 to December 1966 the plant availability was close to 64% including shutdowns because of test fuel failures and loading/unloading of fuel. Disregarding such stops, the availability was close to 90%. The average burnup of the core is about 6200 MWd/t UO{sub 2} : the most highly exposed elements have reached 10000 MWd/t UO{sub 2}. The transition temperature of the reactor tank has been followed closely. The results of the surveillance programme and the implication on the reactor operation are discussed. The reactor is located in a cave in a rock. Some experiences with such a containment are given. To locate failed test-fuel elements a fuel failure location system has been installed. A fission gas collection system has saved valuable reactor time during clean-up of the reactor system following test fuel failures. Apart from one incident with two of the control stations, the plant control and instrumentation systems have functioned satisfactorily. Two incidents with losses of 150 and 200 kg of heavy water have occurred. However, after improved methods for leakage detection had been developed, the losses have been kept better than 50 g/h . Since April 1962 the isotopic purity of the heavy water (14 t) has decreased from 99.75 to 99.62%. The tritium concentration is now slightly above 700 {mu}C/cm{sup 3}. This activity level has not created any serious operational or maintenance problems. An extensive series of water chemistry experiments has been performed to study the influence of various operating parameters on radiolytic gas formation. The main results of these experiments will be reported. Different materials such as mild steel, ferritic steel

  4. 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

  5. Waste minimization through process optimization/integration and resource management at eco-friendly Heavy Water Plants

    International Nuclear Information System (INIS)

    Nageshri, Jagdish; Gupta, S.K.

    2004-01-01

    Heavy Water Board has celebrated 2003 as Environmental Conservation Year captivating a range of enviro-friendly measures. This article attempts to give a brief overview of the outcome of systems and adapted procedures for waste minimization through process integration and resource management at Heavy Water Plants

  6. Effective management of water systems in a chemical industry: a case study at Heavy Water Plant, Manuguru

    International Nuclear Information System (INIS)

    Prahalad, B.; Pandey, B.L.

    1997-01-01

    This paper describes about the important methods of water management in general followed by a description of the water system and measures taken/to be implemented at Heavy Water Plant, Manuguru in particular in order to effectively tackle the effluent water by reuse of the treated effluents

  7. Instrumentation in Heavy Water Plant at Hazira (Paper No. 3.1)

    International Nuclear Information System (INIS)

    Mistry, I.L.

    1992-01-01

    Heavy Water Plant at Hazira is based on monothermal ammonia-hydrogen exchange process and is hooked up to the two, 1350 T/day ammonia plants of M/s. KRIBHCO. An attempt is being made to highlight the salient features of instrumentation, philosophy of selection, brief description of the control system, operational experience, problems faced during commissioning and plant operation and few suggestions to improve the working and reliability of the instrumentation. (author)

  8. Energy conservation measures adopted at Heavy Water Plant, Manuguru

    International Nuclear Information System (INIS)

    Gupta, R.V.; Venugopal, M.

    1997-01-01

    The importance of conservation of energy is well recognised all over the world as the world reserves of fossil fuels will eventually run out depending on the rate of their use. This paper deals with various energy conservation schemes adopted at Heavy Water Plant, Manuguru (HWPM). Most energy conservation measures offer large financial saving with very short pay back periods. This fact has been well recognised by the management of HWPM as well as Heavy Water Board and their wholehearted and enthusiastic approach to energy conservation and energy management yielded very good results in reducing the operating cost. The process of energy conservation is not a one time exercise. Persistent efforts are on to identify the areas like condition of heat exchangers, margins in control valves, steam and condensate leakages etc. for further reduction in energy consumption

  9. Topical and working papers on heavy water requirements and availability

    International Nuclear Information System (INIS)

    The documents included in this report are: Heavy water requirements and availability; technological infrastructure for heavy water plants; heavy water plant siting; hydrogen and methane availability; economics of heavy water production; monothermal, water fed heavy water process based on the ammonia/hydrogen isotopic exchange; production strategies to meet demand projections; hydrogen availability; deuterium sources; the independent UHDE heavy water process

  10. Detection of gaseous heavy water leakage points in CANDU 6 pressurized heavy water reactors

    International Nuclear Information System (INIS)

    Park, T-K.; Jung, S-H.

    1996-01-01

    During reactor operation, the heavy water filled primary coolant system in a CANDU 6 Pressurized Heavy Water (PHWR) may leak through routine operations of the plant via components, mechanical joints, and during inadvertent operations etc. Early detection of leak points is therefore important to maintain plant safety and economy. There are many independent systems to monitor and recover heavy water leakage in a CANDU 6 PHWR. Methodology for early detection based on operating experience from these systems, is investigated in this paper. In addition, the four symptoms of D 2 O leakage, the associated process for clarifying and verifying the leakage, and the probable points of leakage are discussed. (author)

  11. Integrated inspection programs at Bruce Heavy Water Plant

    Energy Technology Data Exchange (ETDEWEB)

    Brown, K C [Ontario Hydro, Tiverton, ON (Canada)

    1993-12-31

    Quality pressure boundary maintenance and an excellent loss prevention record at Bruce Heavy Water Plant are the results of the Material and Inspection Unit`s five inspection programs. Experienced inspectors are responsible for the integrity of the pressure boundary in their own operating area. Inspectors are part of the Technical Section, and along with unit engineering staff, they provide technical input before, during, and after the job. How these programs are completed, and the results achieved, are discussed. 5 figs., 1 appendix.

  12. Integrated inspection programs at Bruce Heavy Water Plant

    International Nuclear Information System (INIS)

    Brown, K.C.

    1992-01-01

    Quality pressure boundary maintenance and an excellent loss prevention record at Bruce Heavy Water Plant are the results of the Material and Inspection Unit's five inspection programs. Experienced inspectors are responsible for the integrity of the pressure boundary in their own operating area. Inspectors are part of the Technical Section, and along with unit engineering staff, they provide technical input before, during, and after the job. How these programs are completed, and the results achieved, are discussed. 5 figs., 1 appendix

  13. Performance of Canadian commercial nuclear units and heavy water plants

    International Nuclear Information System (INIS)

    Woodhead, L.W.; Ingolfsrud, L.J.

    The operating history of Canadian commercial CANDU type reactors, i.e. Pickering generating station-A, is described. Capacity factors and unit energy costs are analyzed in detail. Equipment performance highlights are given. The performance of the two Canadian heavy water plants is described and five more are under construction or planned. (E.C.B.)

  14. The Canadian heavy water situation

    International Nuclear Information System (INIS)

    Dahlinger, A.

    1975-08-01

    Existing heavy water plants in Canada are producing at a satisfactory rate and currently planned capacity is in balance with projected needs. By 1980, we shall have Girdler-Sulphide plants installed with a design capacity of almost 600 kg/h. Effort is required to minimize production costs for heavy water and to ensure that costs do not increase faster than the current inflationary trend. (Author)

  15. Seismic re-evaluation of piping systems of heavy water plant, Kota

    International Nuclear Information System (INIS)

    Mishra, Rajesh; Soni, R.S.; Kushwaha, H.S.; Venkat Raj, V.

    2002-05-01

    Heavy Water Plant, Kota is the first indigenous heavy water plant built in India. The plant started operation in the year 1985 and it is approaching the completion of its originally stipulated design life. In view of the excellent record of plant operation for the past so many years, it has been planned to carry out various exercises for the life extension of the plant. In the first stage, evaluation of operation stresses was carried out for the process critical piping layouts and equipment, which are connected with 25 process critical nozzle locations, identified based on past history of the plant performance. Fatigue life evaluation has been carried out to fmd out the Cumulative Usage Factor, which helps in arriving at a decision regarding the life extension of the plant. The results of these exercises have been already reported separately vide BARC/200I /E/O04. In the second stage, seismic reevaluation of the plant has been carried out to assess its ability to maintain its integ:rity in case of a seismic event. The aim of this exercise is to assess the effects of the maximum probable earthquake at the plant site on the various systems and components of the plant. This exercise is further aimed at ensuring the adequacy of seismic supports to maintain the integrity of the system in case of a seismic event and to suggest some retrofitting measures, if required. Seismic re-evaluation of the piping of Heavy Water Plant, Kota has been performed taking into account the interaction effects from the connected equipment. Each layout has been qualified using the latest provisions of ASME Code Section III, Subsection ND wherein the earthquake loading has been considered as a reversing dynamic load. The maximum combined stresses for all the layouts due to pressure, weight and seismic loadings have been found to be well within the code allowable limit. Therefore, it has been concluded that during a maximum probable seismic event, the possibility of pipe rupture can be safely

  16. Procedures to determine the guaranteed production capacity of a heavy water plant

    International Nuclear Information System (INIS)

    Peculea, Marius

    1999-01-01

    The capacity of a heavy water plant is determined by its design and represents a product between the plant production/hour and the running time. The production/hour is calculated for steady state conditions and the running time is estimated by the designer. Actually, the isotopic separation process takes place in unsteady state conditions and the working time is affected by equipment failure or even damages, after which a relaxation time is necessary for isotopic profile recovery along the separation columns. To determine the actual capacity, the designed capacity is corrected by the product of three coefficients: availability, reliability, and relaxation. The knowledge of the above mentioned coefficients allows the determination of the actual plant capacity; this is important also for further improvements of the separation technology and represents research objectives during the whole existence of such a plant in order to maintain it at an international level of competitiveness. The detailed content of the three coefficients and the way they were determined and experimentally verified on an industrial pilot plant for heavy water production by isotopic exchange at two temperatures in H 2 O - H 2 S system, are presented in this paper. (author)

  17. Antifoaming materials in G.S. (Girlder sulfide) heavy water plants. Thermical stability. Pt. 2

    International Nuclear Information System (INIS)

    Delfino, C.A.

    1986-01-01

    In Girlder sulfide (G.S.) heavy water plants hydrogen sulfide-water systems are inherentely foaming, so the adding of antifoaming materials is of great importance. These may be of high volatility, pyrolizable or chemically unstable in plant operation conditions (water and hydrogen sulfide at 2 MPa, up to 230 deg C). About twenty commercial surfactants were studied from the point of view of their thermical stability. (Author) [es

  18. Operating experience at Heavy Water Plant, Tuticorin (Paper No. 1.7)

    International Nuclear Information System (INIS)

    Periakaruppan, M.; Arumugam, G.; Ayyanar, P.

    1992-01-01

    The initial hurdles faced in the operation of the Heavy Water Plant at Tuticorin warranted major changes in certain design concepts. This paper highlights few of the modifications carried out such as in product concentration, catalyst concentration, amide entry to extraction tower and fluid distribution in cracker tubes. (author)

  19. The development of reactor vessel internal heavy forging for 1000 MW pressurized-water reactor nuclear power plant

    International Nuclear Information System (INIS)

    Zhang Zhifeng; Chen Yongbo; Ding Xiuping; Zhang Lingfang

    2012-01-01

    This Paper introduced the development of Reactor Vessel Internal (RVI) heavy forgings for 1000 MW Pressurized Water Reactor (PWR) nuclear power plant, analyzed the manufacture difficulties and technical countermeasures. The testing result of the product indicated that the performance of RVI heavy forgings manufactured by Shanghai Heavy Machinery Plant Ld. (SHMP) is outstanding and entirely satisfy the technical requirements for RVI product. (authors)

  20. The Canadian heavy water supply program

    International Nuclear Information System (INIS)

    Dahlinger, A.; McNally, P.J.

    1976-06-01

    The performance to date of individual Canadian heavy water plants is described in detail as are the current plant construction plans. These data, when related to the long-term electricity demand indicate that heavy water supply and demand are in reasonable balance and that the CANDU program will not be inhibited because of shortages of the commodity. (author)

  1. Prototype CIRCE plant - industrial demonstration of heavy water production from reformed hydrogen source

    International Nuclear Information System (INIS)

    Spagnolo, D.A.; Boniface, H.A.; Sadhankar, R.R.; Everatt, A.E.; Miller, A.I.; Blouin, J.

    2002-01-01

    Heavy water (D 2 0) production has been dominated by the Girdler-Sulphide (G-S) process, which suffers several intrinsic disadvantages that lead to high production costs. Processes based on hydrogen/water exchange have become more attractive with the development of proprietary wetproofed catalysts by AECL. One process that is synergistic with industrial hydrogen production by steam methane reforming (SMR), the Combined Industrial Reforming and Catalytic Exchange (CIRCE) process, offers the best prospect for commercialization. SMRs are common globally in the oil-upgrading and ammonia industries. To study the CIRCE process in detail, AECL, in collaboration with Air Liquide Canada, constructed a prototype CIRCE plant (PCP) in Hamilton, Ontario. The plant became fully operational in 2000 July and is expected to operate to at least late fall of 2002. To-date, plant operation has confirmed the adequacy of the design and the capability of enriching deuterium to produce heavy water without compromising hydrogen production. The proprietary wetproofed catalyst has performed as expected, both in activity and in robustness. (author)

  2. Canadian heavy water production - 1970 to 1980

    International Nuclear Information System (INIS)

    Galley, M.R.

    1981-01-01

    In the last decade, heavy water production in Canada has progressed from the commissioning of a single unit plant in Nova Scotia to a major production industry employing 2200 persons and operating three plants with an aggregate annual production capability in excess of 1800 Mg. The decade opened with an impending crisis in the supply of heavy water due to failure of the first Glace Bay Heavy Water Plant and difficulty in commissioning the second Canadian plant at Port Hawkesbury. Lessons learned at this latter plant were applied to the Bruce plant where the first two units were under construction. When the Bruce units were commissioned in 1973 the rate of approach to design production rates was much improved, renewing confidence in Canada's ability to succeed in large scale heavy water production. In the early 1970's a decision was made to rehabilitate the Glace Bay plant using a novel flowsheet and this rebuilt plant commenced production in 1976. The middle of the decade was marked by two main events: changes in ownership of the operating plants and initiation of a massive construction program to support the forecast of a rapidly expanding CANDU power station construction program. New production units embodying the best features of their predecessors were committed at Bruce by Ontario Hydro and at La Prade, Quebec, by AECL. The high growth rate in electrical demand did not continue and some new plant construction was curtailed. The present installed production capacity will now probably be adequate to meet anticipated demand for the next decade. Canadian plants have now produced more than 7800 Mg of heavy water at a commercially acceptable cost and with a high degree of safety and compliance with appropriate environmental regulations

  3. Electrolytic process for upgrading heavy water (Preprint No. PD-16)

    International Nuclear Information System (INIS)

    Rammohan, K.; Sadhukhan, H.K.

    1989-04-01

    In the reactor system the heavy water gets depleted in concentration due to leakages, intermixing and vapour collection in boiler vault system etc. Electrolysis of water was used as a secondary plant to enrich the dilute heavy water produced in the primery plant by hydrogen-sulfide-water exchange process. The studies made in the development of this process for the upgrading of downgra ded heavy water by setting up a full size Electrolyser Test Assembly are discussed a nd complete design of a heavy water upgrading plant based on electrolytic process for MAPS and NAPP is described. (author). 7 refs., 5 figs

  4. Indian heavy water programme - challenges and opportunities

    International Nuclear Information System (INIS)

    Aruldoss Kanthiah, W.S.

    2010-01-01

    Discovery of fission of uranium in 1939 opened up hitherto unknown possibilities for utilising the fission energy for use of mankind, mainly for the production of and electrical energy. It was realised that this nuclear energy could be an ideal substitute for the fast depleting fossil fuels which would one day get exhausted. Two main concepts of nuclear power reactor got evolved, one enriched uranium fuelled, ordinary water moderated reactor and another natural uranium fuelled heavy water moderated reactor. The concentration of uranium 235 U needed for ordinary water moderated reactors is 3% but the naturally occurring uranium in India contains only 0.7% of 235 U. The reactors utilising natural uranium as fuel require Heavy Water as moderator. The processing of uranium ore to achieve from 0.7% to 3% is highly complex. Recognising the fact that India has limited uranium resources but rich thorium resources, Dr. Bhabha formulated a three stage nuclear power generation programme for our country. The first generation reactors can use natural uranium as fuel with heavy water as moderator. Since the technology to generate such large scale heavy water to match the urgent need for nuclear power generation was not indigenously available, the technology available with Canada and France was utilised for installation of first generation heavy water plants in India. However, the peaceful nuclear experiment conducted by India in 1974 caused resentment among the countries that supplied Heavy Water technology to India and they stopped all technological help and assistance in nuclear field. Thereafter, it was the story of India going alone in heavy water production. That made India meets successfully all challenges on the way to installation, commissioning and sustained operation of all plants. Today we have six operating Heavy Water plants, spread all over the country. We have reached a stage, a change from a situation of crunch to a level of not only self sufficiency but to a

  5. Probabilistic consequence assessment of hydrogen sulphide releases from a heavy water plant

    International Nuclear Information System (INIS)

    Baynes, C.J.

    1986-05-01

    This report provides a summary of work carried out on behalf of the Atomic Energy Control Board, concerned with the consequences of accidental releases to the atmosphere of hydrogen sulphide (H 2 S) at a heavy water plant. In this study, assessments of consequences are made in terms of the probabilities of a range of possible outcomes, i.e., numbers of fatalities, given a certain release scenario. The report describes the major features of a computer model which was developed to calculate the consequences and their associated probabilities, and the major input data used in applying the model to a consequence assessment of the Bruce heavy water plant (HWP) in Ontario. The results of the sensitivity analyses of the model are summarized. Finally, the results of the consequence assessments of 43 accidental release scenarios at the Bruce HWP are summarized, together with a number of conclusions which were drawn from these results regarding the predicted consequences and the factors which influence them

  6. Uncertainties in gas dispersion at the Bruce heavy water plant

    International Nuclear Information System (INIS)

    Alp, E.; Ciccone, A.

    1995-07-01

    There have been concerns regarding the uncertainties in atmospheric dispersion of gases released from the Bruce Heavy Water Plant (BHWP). The concern arises due to the toxic nature of H 2 S, and its combustion product SO 2 . In this study, factors that contribute to the uncertainties, such as the effect of the shoreline setting, the potentially heavy gas nature of H 2 S releases, and concentration fluctuations, have been investigated. The basic physics of each of these issues has been described along with fundamental modelling principles. Recommendations have been provided on available computer models that would be suitable for modelling gas dispersion in the vicinity of the BHWP. (author). 96 refs., 4 tabs., 25 figs

  7. Uncertainties in gas dispersion at the Bruce heavy water plant

    Energy Technology Data Exchange (ETDEWEB)

    Alp, E; Ciccone, A [Concord Environmental Corp., Downsview, ON (Canada)

    1995-07-01

    There have been concerns regarding the uncertainties in atmospheric dispersion of gases released from the Bruce Heavy Water Plant (BHWP). The concern arises due to the toxic nature of H{sub 2}S, and its combustion product SO{sub 2}. In this study, factors that contribute to the uncertainties, such as the effect of the shoreline setting, the potentially heavy gas nature of H{sub 2}S releases, and concentration fluctuations, have been investigated. The basic physics of each of these issues has been described along with fundamental modelling principles. Recommendations have been provided on available computer models that would be suitable for modelling gas dispersion in the vicinity of the BHWP. (author). 96 refs., 4 tabs., 25 figs.

  8. Canadian heavy water production

    International Nuclear Information System (INIS)

    Dahlinger, A.; Lockerby, W.E.; Rae, H.K.

    1977-01-01

    The paper reviews Canadian experience in the production of heavy water, presents a long-term supply projection, relates this projection to the anticipated long-term electrical energy demand, and highlights principal areas for further improvement that form the bulk of the Canadian R and D programme on heavy water processes. Six Canadian heavy water plants with a total design capacity of 4000Mg/a are in operation or under construction. All use the Girdler-Sulphide (GS) process, which is based on deuterium exchange between water and hydrogen sulphide. Early operating problems have been overcome and the plants have demonstrated annual capacity factors in excess of 70%, with short-term production rates equal to design rates. Areas for further improvement are: to increase production rates by optimizing the control of foaming to give both higher sieve tray efficiency and higher flow rates, to reduce the incapacity due to deposition of pyrite (FeS 2 ) and sulphur (between 5% and 10%), and to improve process control and optimization of operating conditions by the application of mathematical simulations of the detailed deuterium profile throughout each plant. Other processes being studied, which look potentially attractive are the hydrogen-water exchange and the hydrogen-amine exchange. Even if they become successful competitors to the GS process, the latter is likely to remain the dominant production method for the next 10-20 years. This programme, when related to the long-term electricity demand, indicates that heavy water supply and demand are in reasonable balance and that the Candu programme will not be inhibited because of shortages of this commodity. (author)

  9. Coal consumption minimizing by increasing thermal energy efficiency at ROMAG-PROD Heavy Water Plant

    International Nuclear Information System (INIS)

    Preda, Marius Cristian

    2006-01-01

    ROMAG-PROD Heavy Water Plant is a large thermal energy consumer using almost all the steam output from ROMAG-TERMO Power Plant - the steam cost weight in the total heavy water price is about 40%. The steam consumption minimizing by modernization of isotopic exchange facilities and engineering development in ROMAG-PROD Heavy Water Plant results in an corresponding decrease of coal amount burned at ROMAG-TERMO boilers. This decrease could be achieved mainly by the followings ways: - Facility wrappings integrity; - High performance heat exchangers; - Refurbished heat insulations; - Modified condenser-collecting pipeline routes; - High performance steam traps; - Heat electric wire. When coal is burned in Power Plant burners to obtain thermal energy, toxic emissions results in flue gases, such as: - CO 2 and NO x with impact on climate warming; - SO 2 which results in ozone layer thinning effect and in acid rain falls. From the value of steam output per burned coal: 1 GCal steam = 1.41 tone steam = 0.86 thermal MW = 1.1911 tones burned coal (lignite), it is obvious that by decreasing the thermal energy consumption provided for ROMAG PROD, a coal amount decrease is estimated at about 45 t/h, or about 394,200 t/year coal, which means about 10% of the current coal consumption at ROMAG-TERMO PP. At the same time, by reducing the burned coal amount, an yearly decrease in emissions into air to about 400,000 tones CO 2 is expected

  10. Direction of Heavy Water Projects

    International Nuclear Information System (INIS)

    1984-07-01

    Summary of the activities performed by the Heavy Water Projects Direction of the Argentine Atomic Energy Commission from 1950 to 1983. It covers: historical data; industrial plant (based on ammonia-hydrogen isotopic exchange); experimental plant (utilizing hydrogen sulfides-water process); Module-80 plant (2-3 tons per year experimental plant with national technology) and other related tasks on research and development (E.A.C.) [es

  11. Prototype CIRCE plant-industrial demonstration of heavy-water production from a reformed hydrogen source

    Energy Technology Data Exchange (ETDEWEB)

    Spagnolo, D.A.; Boniface, H.A.; Sadhankar, R.R.; Everatt, A.E.; Miller, A.I. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Blouin, J. [Air Liquide Canada, Hamilton, Ontario (Canada)

    2002-09-01

    Heavy-water (D{sub 2}0) production has been dominated by the Girdler-Sulphide (G-S) process, which suffers several intrinsic disadvantages that lead to high production costs. Processes based on hydrogen/water exchange have become more attractive with the development of proprietary wetproofed catalysts by AECL. One process that is synergistic with industrial hydrogen production by steam methane reforming (SMR), the combined industrial reforming and catalytic exchange (CIRCE) process, offers the best prospect for commercialization. SMRs are common globally in the oil upgrading and ammonia industries. To study the CIRCE process in detail, AECL, in collaboration with Air Liquide Canada, constructed a prototype CIRCE plant (PCP) in Hamilton, ON. The plant became fully operational in 2000 July and is expected to operate to at least the late fall of 2002. To date, plant operation has confirmed the adequacy of the design and the capability of enriching deuterium to produce heavy water without compromising hydrogen production. The proprietary wetproofed catalyst has performed as expected, both in activity and in robustness. (author)

  12. Prototype CIRCE plant-industrial demonstration of heavy-water production from a reformed hydrogen source

    International Nuclear Information System (INIS)

    Spagnolo, D.A.; Boniface, H.A.; Sadhankar, R.R.; Everatt, A.E.; Miller, A.I.; Blouin, J.

    2002-09-01

    Heavy-water (D 2 0) production has been dominated by the Girdler-Sulphide (G-S) process, which suffers several intrinsic disadvantages that lead to high production costs. Processes based on hydrogen/water exchange have become more attractive with the development of proprietary wetproofed catalysts by AECL. One process that is synergistic with industrial hydrogen production by steam methane reforming (SMR), the combined industrial reforming and catalytic exchange (CIRCE) process, offers the best prospect for commercialization. SMRs are common globally in the oil upgrading and ammonia industries. To study the CIRCE process in detail, AECL, in collaboration with Air Liquide Canada, constructed a prototype CIRCE plant (PCP) in Hamilton, ON. The plant became fully operational in 2000 July and is expected to operate to at least the late fall of 2002. To date, plant operation has confirmed the adequacy of the design and the capability of enriching deuterium to produce heavy water without compromising hydrogen production. The proprietary wetproofed catalyst has performed as expected, both in activity and in robustness. (author)

  13. Role of knowledge based engineering in Heavy Water Plants and its relevance to chemical industry

    International Nuclear Information System (INIS)

    Sonde, R.R.

    2002-01-01

    The development of heavy water technology under the Department of Atomic Energy in India is carried out based on a mission oriented programme and this was backed up by a committed and highly trained manpower with a single minded pursuit to achieve the goal of making India self-sufficient in this challenging area. The paper gives step by step methodology followed in completion of the above mission which has become a benchmark in the chemical industry. A large sized chemical industry (Heavy Water plant being once such industry) has many features which are similar. The process design typically includes design of reactors, distillation columns, heat exchange networks, fluid transfer machinery, support utility systems etc. Besides, there are other issues like safety engineering, selection of materials, commissioning strategies and operating philosophies which are quite common to almost all chemical industries. Heavy water board has engineered and set up large scale heavy water plants and the technology for production of heavy water is completely assimilated in India and this paper tries to bring about some of the strategies which were instrumental in achieving this. The story of success in this technology can most certainly be followed in development of any other process technology. The important factors in the development of this technology is based on integration of R and D, process design, engineering backup, safety features, role of good construction and project management and good operating practices. One more important fact in this technology development is continuous improvement in operation and use of knowledge based engineering for debottlenecking. (author)

  14. Operating experiences of Heavy Water Plant at Talcher using bithermal ammonia-hydrogen exchange process (Paper No. 1.9)

    International Nuclear Information System (INIS)

    Haldar, T.K.; Manoj Kumar; Ramamurty, C.B.

    1992-01-01

    A heavy water plant employing bithermal ammonia-hydrogen exchange process was set up at Talcher (India). The energy consumption in the process is lower as compared to monothermal process. The plant performance was affected by various problems and has resulted in low heavy water production. The problems are: (i)formation of solid deposits, (ii)inability of exchange towers to process design gas flow rates, (iii)inadequate exchange efficiency of the sieve trays provided as exchange trays, and (iv)differential amide concentration in different plant sections. These problems and their effect on the overall plant performance are discussed in detail and modifications to improve the performance are suggested. (author). 4 figs

  15. Piping analysis for the life extension of Heavy Water Plant, Kota

    International Nuclear Information System (INIS)

    Mishra, Rajesh; Soni, R.S.; Kushwaha, H.S.; Venkat Raj, V.

    2001-02-01

    Heavy water production in India has achieved many milestones in the past. One of the most successfully running heavy water plant situated at Kota (Rajasthan) is on the verge of completion of its design life in near future. Heavy Water Plant, Kota is hydrogen sulfide based plant. Various exercises have been planned with an aim to assess the fatigue usage for the various components of these plants in order to extend their life. Considering the process parameters and past history of the plant performance, 25 process critical nozzle locations and connected piping systems are identified. Analyses have been carried out for these critical piping systems for mainly two kinds of loading, viz. sustained loads and the expansion loads. The static analysis has been carried out to find the induced stress levels due to sustained as well as thermal expansion loading as per the design code ANSI B31.3. Due consideration is given to the design corrosion allowance while evaluating the stresses due to sustained loads. At the locations where induced stresses (S 1 ) due to the sustained loads are exceeding the allowable limits (S h ), exercises have been carried out considering the reduced corrosion allowance value. This strategy is adopted due to the fact that the corrosion measurements carried out at site at various critical locations show a very low rate of corrosion. Where it is found that system is getting qualified with reduced corrosion allowance values, it is recommended to keep that location under periodic monitoring. The strategy adopted for carrying out the analysis for thermal expansion loading is to qualify the system as per the code allowable value (S a ). Where it is found that the stresses are more than the allowable value, credit of liberal allowable value as suggested in the code i.e., with the addition of the term (S h -S 1 ) to the allowable stress (S a ) value, has been taken. If at any location, it is found that the problem of high thermal stress still persists, the

  16. Some environmental effects of emissions from CANDU nuclear generating stations and heavy water plants

    International Nuclear Information System (INIS)

    Effer, W.R.

    Non-radioactive releases during normal operation of Ontario Hydro's nuclear generating stations and heavy water plants are summarized and related to existing regulations and guidelines. Low-grade heat in the circulating cooling water discharge is the most important of the non-radioactive effluents. Some of the hydrological, biological and water quality aspects of thermal discharges are discussed in relation to the operation of Ontario Hydro's thermal generating stations on the Great Lakes. Chemical releases to air or water include chlorine, hydrogen sulphide, water treatment plant effluents, oily waste water and sewage lagoon effluents. The significance of the first two of these releases to the environment is reviewed, particularly in relation to Great Lakes water quality and biological concerns. (author)

  17. Heavy water. A production alternative for Venezuela

    International Nuclear Information System (INIS)

    A survey of heavy water production methods is made. Main facts about isotopic and distillation methods, reforming and coupling to a Hydrogen distillation plant are presented. A feasibility study on heavy water production in Venezuela is suggested

  18. Hazard and operability study of Heavy Water Plant, Manuguru

    Energy Technology Data Exchange (ETDEWEB)

    Nayak, S K; Khilnaney, V K [Heavy Water Board, Department of Atomic Energy, Mumbai (India)

    1994-06-01

    The chemical process industry faces the tough challenge of achieving design productivity while maintaining high standards of safety. This task is particularly difficult than handling hazardous chemicals. Hazard and operability study (HazOp) is a technique which involves systematic and thorough study by a multidisciplinary team. This technique provides a means to analyse the design and modes of operations of a plant systematically so as to identify the potential occurrence of hazardous events and operational problems. HazOp is based on the premise that a hazard is not realised if the process is operated within its design intent. This paper gives an overall view of the HazOp study carried out at Heavy Water Plant, Manuguru. Some selected recommendations from this study are highlighted. (author). 2 refs., 5 figs.

  19. Process for the preparation of ammonia and heavy water

    International Nuclear Information System (INIS)

    Mandrin, C.

    1980-01-01

    A process for the production of ammonia and heavy water comprises the steps of enriching a flow of water with deuterium in a monothermal isotropic process; supplying a first portion of the deuterium-enriched water to a heavy water preparation plant to produce heavy water and hydrogen; storing a second portion of the deuterium-enriched water substantially without interruption during the colder half of a year; electrolytically dissociating the stored deuterium-enriched water substantially without interruption during the wamer half of a year to form hydrogen; storing a portion of the electrolytically-produced hydrogen during said warmer half of a year while supplying the remainder to a synthesis circuit of a synthesizing plant and subsequently supplying the stored hydrogen to the synthesis circuit during said colder half of a year; removing some of the synthesis gas mixture from the synthesis circuit of the synthesizing plant; burning the removed synthesis gas mixture with air to produce a mixture consisting mainly of water and nitrogen; thereafter condensing and separating the water from the mixture of water and nitrogen; supplying the nitrogen of the mixture of water and nitrogen, the hydrogen from the heavy water preparation plant and the electrolytically-produced hydrogen to the synthesis circuit of the synthesizing plant to produce ammonia; and collecting deuterium-depleted water resulting from said burning step and feeding the collected deuterium-depleted water into the monothermal process

  20. Power control device for heavy water moderated reactor

    International Nuclear Information System (INIS)

    Matsushima, Hidesuke; Masuda, Hiroyuki.

    1978-01-01

    Purpose: To improve self controllability of a nuclear power plant, as well as enable continuous power level control by a controlled flow of moderators in void pipes provided in a reactor core. Constitution: Hollow void pipes are provided in a reactor core to which a heavy water recycle loop for power control, a heavy water recycle pump for power control, a heavy water temperature regulator and a heavy water flow rate control valve for power control are connected in series to constitute a heavy water recycle loop for flowing heavy water moderators. The void ratio in each of the void pipes are calculated by a process computer to determine the flow rate and the temperature for the recycled heavy water. Based on the above calculation result, the heavy water temperature regulator is actuated by way of a temperature setter at the heavy water inlet and the heavy water flow rate is controlled by the actuation of the heavy water flow rate control valve. (Kawakami, Y.)

  1. Asymmetric Modeling of the Industrial Heavy Water Plant (PIAP)

    International Nuclear Information System (INIS)

    Teruel, Federico; Aprea, J; Guido Lavalle, German

    2000-01-01

    Software of asymmetric stationary simulation for the Industrial Heavy Water Plant (PIAP) was developed, based on an existing symmetric simulator (Brigitte 2.0).This software allows to turn off some of the isotopic enrichment twin units present in the plant and to simulate them asymmetrically, in other words, with different selection of parameters between twins.Other incorporations were done, such as passing flows between units and entering flows in strategic points of the plant.The iterative system in which the symmetric simulator is based was insufficient to develop the asymmetric simulator, so the system was modeled according to an implicit scheme for the units that form the simulator.This type of resolution resulted in a simulator that supports a big range of boundary conditions and internal parameters.Moreover, the time of calculus is short (∼3 minutes), making it actually useful.The asymmetric simulator is at the PIAP now, for its study and validation. It shows expected tendencies and results according to the symmetric simulator already validated

  2. Technical and economical feasibility studies and preliminary plan of a heavy water plant by the criogenic distillation method of hydrogen

    International Nuclear Information System (INIS)

    Dias Vargas, F.

    1983-01-01

    This paper presents the pre-feasibility study of a heavy water production plant, both from the technical and economical point of view. Criogenic distillation of hydrogen is used as the final enrichment stage. The deuterium source is water treated previously by a process of enrichment based on the water-hydrogen isotopic exchange. The economical analysis is aimed at the study of the feasibility of the installation of a heavy water moderated reaction in Chile. General properties of heavy water are presented and also the various materials of its enrichment at the industrial scale. The plant itself has a first stage based on the water-hydrogen isotopic exchange procesS, where deuterium is extracted from the water by the hydrogen which is subsequently treated in a criogenic distillation stage. An important fact of the plant analysis is the calculation of heat exchangers mainly in relation to the problem posed by tHe hydrogen's low point of liquifaction. The distillation units are also treated and designed. The economic evaluation produces project diScount rates of 15.71% and 21.97%, for 25 tons/year and 40 tons/year of production capacity. The heavy water price used for these evaluation was 600 $/Kg

  3. Standards for deuterium analysis requirements of heavy water plants (Preprint No. CA-1)

    Energy Technology Data Exchange (ETDEWEB)

    Rathi, B N; Gopalakrishnan, V T; Alphonse, K P; Pawar, P L; Sadhukhan, H K [Bhabha Atomic Research Centre, Bombay (India). Heavy Water Div.

    1989-04-01

    Accurate analysis of deuterium, covering the entire range, is of great importance in production of heavy water. Most of the methods for determination of deuterium in gas or liquid samples require appropriate standards. Since density of pure protium oxide and pure deuterium oxide has been determined very accurately by a large number of workers and density of mixtures of H{sub 2}O and D{sub 2}O follows a linear relation, it is possible to use accurate density determination for measurement of deuterium content. Float method for density measurements was improved further and used for the preparation of primary heavy water standards in high and low deuterium ranges. Heavy water plant laboratories require gas standards (ammonia synthesis gas matrix), in addition to low deuterium water standards, for calibration of mass spectrometers. SLAP (Standard Light Antarctic Precipitation, D/D+H = 89.02+-0.05ppm) and SMOW (Standard Mean Ocean Water, D/D+H =155.76+-0.05ppm) available from IAEA, Vienna, along with water practically free from deuterium, were used as standards to prepare secondary liquid standards. These secondary standards were subsequently reduced and mixed with pure nitrogen to obtain D/D+H standards in syngas matrix. (author). 8 refs., 2 figs.

  4. Probabilistic consequence assessment of hydrogen sulphide releases from a heavy water plant

    International Nuclear Information System (INIS)

    1983-01-01

    This report is concerned with the evaluation of the consequences to the public of an accidental release of hydrogen sulphide (H 2 S) to the atmosphere following a pipe or pressure envelope failure, or some other process upset, at a heavy water plant. It covers the first stage of a programme in which the nature of the problem was analyzed and recommendations made for the implementation of a computer model. The concepts of risk assessment and consequence assessment are discussed and a methodology proposed for combining the various elements of the problem into an overall consequence model. These elements are identified as the 'Initiating Events', 'Route to Receptor' and 'Receptor Response' and each is studied in detail in the report. Such phenomena as the blowdown of H 2 S from a rupture, the initial gas cloud behaviour, atmospheric dispersion and the toxicity of H 2 S and sulphur dioxide (SO 2 ) are addressed. Critical factors are identified and modelling requirements specified, with special reference to the Bruce heavy water plant. Finally, an overall model is recommended for implementation at the next stage of the programme, together with detailed terms of reference for the remaining work

  5. Design and manufacturing of canned motors for exchange towers of heavy water plants (Preprint No. ED-4)

    International Nuclear Information System (INIS)

    Bhattacharya, S.; Badodkar, D.N.; Govindarajan, G.

    1989-04-01

    Canned motors which are specially munufactured for exchange towers of heavy water plants are supposed to be very reliable and rugged. Hence these motors are built with good safety margin in design. The efficiency of the motor is not the prime consideration but it should not fail under overload conditions. The designed output is higher than the output under normal operating condition. The failure of two pumps in one stage will need the opening of the tower and results in shutdown of the plant which will affect the production of heavy water. Keeping these things in mind, little higher capacity motors are used for this application. (author)

  6. 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

    In general, heavy water reactor (HWR) nuclear power plant (NPP) owners would like to keep their NPPs in service as long as they can be operated safely and economically. Their decisions are depending on essentially business model. They involve the consideration of a number of factors, such as the material condition of the plant, comparison with current safety standards, the socio-political climate and asset management/ business planning considerations. Continued plant operation, including operation beyond design life, called 'long term operation, depends, among other things, on the material condition of the plant. This is influenced significantly by the effectiveness of ageing management. Key attributes of an effective plant life management program include a focus on important systems, structure and components (SSCs) which are susceptible to ageing degradation, a balance of proactive and reactive ageing management programmes, and a team approach that ensures the co-ordination of and communication between all relevant nuclear power plant and external programmes. Most HWR NPP owners/operators use a mix of maintenance, surveillance and inspection (MSI) programs as the primary means of managing ageing. Often these programs are experienced-based and/or time-based and may not be optimised for detecting and/or managing ageing effects. From time-to-time, operational history has shown that this practice can be too reactive, as it leads to dealing with ageing effects (degradation of SSCs) after they have been detected. In many cases premature and/or undetected ageing cannot be traced back to one specific reason or an explicit error. The root cause is often a lack of communication, documentation and/or co-ordination between design, commissioning, operation or maintenance organizations. This lack of effective communication and interfacing frequently arises because, with the exception of major SSCs, such as the fuel channels or steam generators, there is a lack of explicit

  7. Energy conservation measures adopted in heavy water plants (Paper No. 1.8)

    International Nuclear Information System (INIS)

    Sundaresan, S.; Lakshmanan, S.

    1992-01-01

    Energy use can be significantly reduced in the process plants by systematically reviewing the original design and operating practices. While designing a chemical process plant, sometimes the designers go for high margin in certain areas anticipating to suit process conditions which finally result in wastage of energy if those conditions are not realised in the actual operation of the plant. Similarly some of the operating practices evolved since commissioning, might be resulting in uneconomical use of energy when they are not checked by the regular review of the operating practices. This paper deals with the various efforts made by Heavy Water Plant, Tuticorin, in identifying the potential energy losses and steps taken to minimise them, which not only resulted in substantial energy savings but also helped in debottle-necking of the plant. (author)

  8. IR analyzer spots heavy water leaks

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    A correlation spectrometer developed by Barringer Research Ltd. (in collaboration with Atomic Energy of Canada and Ontario Hydro) is used to measure HDO concentrations in DTO in the final (distillation) stage of heavy-water production. A unit has been installed at Bruce Heavy Water Plant. Previously, such spectrometers had been installed to detect heavy-water leaks in CANDU reactors. The principle on which the instrument works is explained, with illustrations. It works by comparing the absorption at 2.9 μm, due to HDO, with that at 2.6 μm, due to both HDO and D 2 O. (N.D.H.)

  9. Phytoremediation of water bodies contaminated with radioactive heavy metal

    International Nuclear Information System (INIS)

    Yan Zhen; Yuan Shichao; Ling Hui; Xie Shuibo

    2012-01-01

    The sources of the radioactive heavy metal in the water bodies were analyzed. The factors that affect phyto remediation of water contaminated with radioactive heavy metal were discussed. The plant species, mechanism and major technology of phyto remediation of water contaminated with radioactive heavy metal were particularly introduced. The prospective study was remarked. (authors)

  10. Ammonia-water exchange front end process for ammonia-hydrogen heavy water plants (Preprint No. PD-1)

    International Nuclear Information System (INIS)

    Sadhukhan, H.K.; Varadarajan, T.G.; Nair, N.K.; Das, S.K.; Nath, G.K.

    1989-04-01

    The ammonia-hydrogen exchange process, which utilizes the deutrium exchange between liquid ammonia and gaseous hydrogen is a parasitic process and the heavy water plants (HWP) based on this process has to be linked with the fertilizer plant (FP) for its enormous requirements of hydrogen (synthesis gas, N 2 +3H 2 ). This dependence of HWP on FP gives rise to certain constraints which are listed. These deficiencies of the ammonia-hydrogen process can be overcome to a great extent by delinking the HWP from FP by incorporating NH 3 -H 2 O exchange as the front end step. In addition to the elimination of the above limitations, by employing water as the ultimate feed for the HWP, the plant capacity can be increased substantially and this would go a long way in achieving economies of the large capacity plants. A schematic diagram of this integrated plant is given. Some of the results of developmental efforts and feasibility studies of this NH 3 -H 2 O exchange are briefly reviewed. (author). 4 figs

  11. Studies on silicone based antifoaming agents to be used in G.S. (Girlder sulfide) heavy water plants

    International Nuclear Information System (INIS)

    Delfino, C.A.

    1986-01-01

    In Girlder sulfide (G.S.) heavy water plants hydrogen sulfide-water systems are inherentely foaming, so the adding of antifoaming materials is of great importance. These may be of high volatility, pyrolizable or chemically unstable in plant operation conditions (water and hydrogen sulfide at 2MPa, up to 230 deg C). Six commercial silicone based antifoaming agents were studied from the point of view of their chemical and thermical stability in order to select the most suitable. (Author) [es

  12. Antifoaming materials studies in G.S. (Girlder sulfide) heavy water plants. Chemical and thermical stability. Pt. 3

    International Nuclear Information System (INIS)

    Delfino, C.A.; Rojo, E.A.

    1988-01-01

    In Girlder sulfide (G.S.) heavy water plants hydrogen sulfide-water systems are inherentely foaming, so the adding of antifoaming materials is of great importance. These may be of high volatility, pyrolizable or chemically unstable in plant operation conditions (water and hydrogen sulfide at 2 MPa, up to 230 deg C). Five commercial surfactants were studied from the point of view of their chemical and thermical stability in order to select the most suitable. (Author) [es

  13. Development of green belt for Heavy Water Plant (Manuguru) (Paper No. 4.4)

    International Nuclear Information System (INIS)

    Sharma, R.N.; Wagh, K.S.; Ranade, G.N.; Mulgund, D.T.

    1992-01-01

    There has been an awakening worldwide regarding environmental degradation. So there is an urgent need of a policy on conservation of ecology while planning projects. Provision for suitable tree plantation as a green belt around a chemical industrial plant is a proven remedy to minimise the impact of gaseous effluents in addition to retain a green cover in the area. This paper describes the steps taken at Heavy Water Plant, Manuguru for providing green belt from a very early stage of execution of the project. (author)

  14. Modern technologies and equipment for environment and sustainable development at ROMAG-PROD Heavy Water Plant

    International Nuclear Information System (INIS)

    Preda, Marius Cristian; Patrascu, Mihai; Pop, Artimisia; Chilom, Rodica

    2004-01-01

    At ROMAG-PROD Heavy Water Plant, the sustainable development concept incorporates as a priority the environmental protection through the production process technology. Norway's Prime Minister, Mr. Gro Harlem Brundtland used the concept of 'sustainable development' in 1987, when as President of International Commission for Environment and Sustainable Development, he presented his report 'Our common future'. Sustainable development means that development that allows satisfying our present needs without spoiling the next generation capacity to meet their own needs. Any technology has both advantages and disadvantages; when considering the concept of sustainable development we have to take into account all the aspects, namely: - causes identification and review; - results evaluation; - corrective and preventive actions. Thus, ROMAG-PROD Heavy Water Plant has implemented a typical environment management system by means of what the general and specific objectives have been established, these objectives being stated in an Environment Policy Declaration: - Environment Management System as per SR EN ISO 14001/1997; - Quality Management System as per SR EN ISO 9001/2000; - IQNet- The International Certification Network. The paper presents the modern equipment for emissions and in-missions management with real time data transmission, for air and water as environment elements. Section two deals with trial of modern technology for industrial discharged wastewater treatment using the method of controlled batching of surface-active materials. Investigations on method application and laboratory testing as well as findings are given. As a conclusion, one can state that ROMAG-PROD Heavy Water Plant, has as one of its main concern keeping on high standards the safety of its equipment operation, sustainable development and risk eliminating so that neither environment or the population in vicinity is affected. (authors)

  15. Development of a purification system at Dhruva to treat oil contaminated and chemically impure heavy water

    International Nuclear Information System (INIS)

    Suttraway, S.K.; Mishra, V.; Bitla, S.V.; Ghosh, S.K.

    2006-01-01

    Dhruva, a 100 MW (thermal) Research reactor uses Heavy Water as moderator, reflector and coolant. Normally during plant operation, the Heavy water from the system gets removed during operational and maintenance activities and this collected heavy water gets degraded and contaminated in the process. The degraded heavy water meeting the chemical specification requirement of the up gradation plant is sent for up gradation. Part of the Heavy water collected is contaminated with various organic and inorganic impurities and therefore cannot be sent for IP up gradation as it does not meet the chemical specification of the up gradation plant. This contaminated Heavy water was being stored in SS drums. Over the years of Reactor operation reasonable amount of contaminated Heavy water got collected in the plant. This Heavy water collected from leakages, during routine maintenance, operational activities and fuelling operation had tritium activity and variety of contamination including oil, chlorides, turbidity due to which the specific conductivity was very high. It was decided to purify this Heavy water in house to bring it up to up gradation plant chemical specification requirement. There were number of challenges in formulating a scheme to purify this Heavy water. The scheme needed to be simple and compact in design which could be set up in the plant itself. It should not pose radiological hazards due to radioactive Heavy water during its purification and handling. The contaminated Heavy water collected in drums had varying chemistry and IP. The purification plant should be able to do batch processing so that the different IP and chemical quality of Heavy water stored in different drums are not mixed during purification. It should be capable of removing the oil, chlorides, turbidity and decrease the conductivity to acceptable limits of the Up gradation plant. A purification plant was developed and commissioned after detail laboratory studies and trials. This paper explains

  16. Improvements on heavy water separation technology by isotopic water-hydrogen sulfide exchange

    International Nuclear Information System (INIS)

    Peculea, M.

    1987-01-01

    A series of possible variance is presented for the heavy water separation technology by isotopic H 2 O-H 2 S exchange at dual temperatures. The critical study of these variants, which are considered as characteristic quantities for the isotopes transport (production) and the extraction level is related to a dual temperature plant fed by liquid and cold column, which is the up-to-date technology employed in all heavy water production plants as variants of following plants are studied: dual temperature plant with double feeding; dual-temperature plant with equilibrium column (booster); dual-temperature-dual-pressure plant. Attention is paid to the variant with equilibration column (booster), executed and tested at the State Committee for Nuclear Energy and to the dual-temperature-dual pressure plant which presents the highest efficiency. (author)

  17. Finishing and upgrading of heavy water

    International Nuclear Information System (INIS)

    Butler, J.P.; Hammerli, M.

    1981-01-01

    This invention provides a process and apparatus for deuterium enrichment as a final stage in a heavy water plant, for continuous on-line enrichment of the heavy water in moderator and heat transfer systems in heavy water nuclear reactors, and for enrichment of hevy water that has been downgraded with natural water during the course of operating a heavy water nuclear reactor. The method comprises contacting partially-enriched heavy water feed in a catalyst column with hydrogen gas (essentially D 2 ) orginating in an electrolysis cell so as to enrich the feed water with deuterium extracted from the electrolytic hydrogen gas and passing the deuterium-enriched water to the electrolysis cell. The apparatus comprises a catalyst isotope exchange column with hydrogen gas and liquid water passing through in countercurrent isotope exchange, an electrolysis cell, a dehumidifer-scrubber; and means for passing the liquid water enriched in deuterium from the catalyst column through the dehumidifer-scrubber to the electrolysis cell, for passing the hydrogen gas evolved in the cathode side of the cell through the dehumidifier-scrubber to the catalyst column, for passing the hydrogen gas from the catalyst column to an output, for introducing an input water feed to the upper portion of the catalyst column, and for taking a product enriched in deuterium from the system. (LL)

  18. Determination of heavy water in heavy water - light water mixtures

    International Nuclear Information System (INIS)

    Sanhueza M, A.

    1986-01-01

    A description about experimental methodology to determine isotopic composition of heavy water - light water mixtures is presented. The employed methods are Nuclear Magnetic Resonance Spectroscopy, for measuring heavy water concentrations from 0 to 100% with intervals of 10% approx., and mass Spectrometry, for measuring heavy water concentrations from 0.1 to 1% with intervals of 0.15% approx., by means of an indirect method of Dilution. (Author)

  19. Determination of heavy toxic metals in the environment indicator specimens (water, river sediment and kangkung plant) of Muria terrestrial

    International Nuclear Information System (INIS)

    J Djati Pramana; Sukirno; Bambang Irianto

    2004-01-01

    Analysis and evaluation contain of heavy toxic metals in the water kangkung plant (Ipomea reptans poir) and river sediment of five rivers sampling location at peninsula Muria region by NAA Instrumental method has been done. The method of sampling. preparation although analysis method according to standard procedure of environmental specimens analysis. Accordingly the quality standard of water group C although group D. the sample from fifth river location sampling was under allowed maximum Cd concentration. Correlation between variable location and kind of indicators to heavy metal concentration was shown by coefficient of Pearson correlation. Interpretation by statistic correlation was obtained. Correlation between kind indicators was indicated that river water has significant correlation with the kangkung plant about Cd concentration. (author)

  20. Measurement of concentration of heavy water

    International Nuclear Information System (INIS)

    Tsukamoto, Yuichi; Kondo, Mitsuo; Sakurai, Naoyuki

    1979-01-01

    The concentration of heavy water is measured as one of the technical management in the Fugen plant. The heavy water is used as the moderator in the reactor. The measuring method depends on the theory of light absorption. The light absorption range of heavy water spreads from near infrared to infrared zone. The near infrared absorption was adopted for the purpose, as the absorption is much larger in infrared zone, and the measurement has to be conducted, limiting the apparent absorption. This measuring method is available to determine the concentration of heavy water in the broad range exactly. The preparation of heavy water sample and the measurement of the absorption spectra of near infrared ray are explained, as the experimental procedure. The sample cell was made of quartz, and the spectroscope was the Hitachi 323 type. The resolving power is 100 nm and 27 nm for the wave length of 1000 nm and 2500 nm, respectively. Concerning the measured results, the absorption was recorded in the wave length range from 600 nm to 2600 nm, and for the heavy water concentration range from 0 to 99.77 wt. %. The peaks of absorption were located at the wave length of 1450, 1660, 1920, 1970, 2020 and 2600 nm. The three kinds of fundamental vibration mode of the molecules of both light and heavy water are shown, and the peaks belong to H 2 O, HDO and D 2 O, respectively. The relation between the absorption and the heavy water concentration, and that between the transmissivity and the wave length are shown, when the cell thickness was varied to 5 mm and 20 mm, and the heavy water concentration to 21%, 62% and 99.85%. (Nakai, Y.)

  1. The need for accurate deuterium analysis in a heavy water plant and its achievement

    International Nuclear Information System (INIS)

    Singh, R.R.; Pradhan, D.G.

    1979-01-01

    Importance of Mass Spectrometer as an analytical tool for deuterium analysis in heavy water plants is discussed. Some of the important requirements such as memory effect and H 3 + correction are described with reference to the Mass Spectrometer used at HWP (Talcher). For achieving the accuracy required, use of international deuterium standards and error estimation found by intercalibration are discussed. (auth.)

  2. Modifications carried out in Heavy Water Plant, Tuticorin for maximising productivity (Paper No. 1.6)

    International Nuclear Information System (INIS)

    Periakaruppan, M.; Sunderesan, S.; Chellapandi, D.

    1992-01-01

    Many modifications have been carried out in Heavy Water Plant, Tuticorin, after commissioning of the plant in July 1978. During the initial 4/5 years many teething problems were faced and they have been tackled effectively with suitable modifications which resulted in sustained production from the year 1984 onwards. In this paper some modifications carried out and changes in operational procedures adopted which resulted in achieving sustained production year after year since 1984 are described. (author)

  3. Experiences from the Swedish programme - heavy water and natural uranium in the Aagesta cogeneration plant

    International Nuclear Information System (INIS)

    Oestman, Alvar

    2002-11-01

    A short review of the Swedish programme for nuclear power in the 50's and the 60's is given, and in particular a description of the operating experiences of the Aagesta nuclear cogeneration plant, producing district heating for the south Stockholm area (12 MW el and 68 MW heat ). The original Swedish nuclear programme was built on heavy water and natural uranium and had the objective to construct small nuclear plants in the vicinity of some 10 large cities in south and middle Sweden. Aagesta was the only full-scale plant to be built according to this programme, as Sweden adopted the light-water reactor policy and eventually constructed 12 large reactors at four sites. The report is based on the experiences of the author from his work at the Aagesta plant in the sixties. In an appendix, the experiences from Vattenfall (the Swedish electric utility which took over the operating responsibility for the Aagesta plant), of the plant operation is reviewed

  4. on the use of selected aquatic plants in tracing of some heavy metal pollutants

    International Nuclear Information System (INIS)

    Hammad, D.M.; Tawfik, T.A.

    2004-01-01

    three aquatic macrophyte plants namely; Cyperus Rotundus (emergent plant), Phragmits Australis (emergent plant) and Echhornia crassipes (floating plant) were selected to measure their ability for uptake of heavy metal pollutants from their ambient environments and to decide the possibility of using such plants in practical applications of water and sediment purity monitoring and decontamination . these plants with the corresponding water and sediment samples were collected from El-rayah El-menoufy (comparable site), near El- kanater El- khayria which receives its water directly from the River Nile (Dommietta branch) and from two drains namely. El remal drain (sewage drain), which receives its water from Abu-rawash waste water treatment plant and El-tibeen drain (mixed agricultural and industrial drain), located at the right bank of the River Nile and surrounded by huge industrial factories and receives its water from El-khashab canal. the water, sediment and plant samples collected from the selected areas were analyzed for anions, cations and heavy metal contents. studying and comparing the accumulative capacity of the emergent and floating plants to measure their ability in phytoremediatic applications and heavy metal pollution studies were performed . the correlations between the heavy metal concentrations in plants and in their ambient environments were calculated and the potential of the examined plants for pollution monitoring was estimated . in addition, the natural radioactivity of the environmental sediments was evaluated for K-40, Th -232 and Ra-226. the results obtained were compared with the international reference values

  5. Critical evaluation of heavy water project at Thal (Preprint No. PM-5)

    International Nuclear Information System (INIS)

    Jayakumar, N.S.

    1989-04-01

    The project known as Thal Ammonia Extension was a heavy water project successfully completed by Rashtriya Chemicals and Fertilizers (RCF) Ltd. The project consisted of erecting a heavy water plant of 110 tons/year capacity at Thal. The process Know-how and engineering of the plant was supplied by the Heavy Water Projects Division of the Department of Atomic Energy. Salient features of the project, management features which resulted in fast completion of erection, bottlenecks faced and engineering innovations adopted for efficient operation of the plant are described. Some modifications which can lead to smoother operation are listed. (M.G.B.)

  6. Interactions between plant hormones and heavy metals responses.

    Science.gov (United States)

    Bücker-Neto, Lauro; Paiva, Ana Luiza Sobral; Machado, Ronei Dorneles; Arenhart, Rafael Augusto; Margis-Pinheiro, Marcia

    2017-01-01

    Heavy metals are natural non-biodegradable constituents of the Earth's crust that accumulate and persist indefinitely in the ecosystem as a result of human activities. Since the industrial revolution, the concentration of cadmium, arsenic, lead, mercury and zinc, amongst others, have increasingly contaminated soil and water resources, leading to significant yield losses in plants. These issues have become an important concern of scientific interest. Understanding the molecular and physiological responses of plants to heavy metal stress is critical in order to maximize their productivity. Recent research has extended our view of how plant hormones can regulate and integrate growth responses to various environmental cues in order to sustain life. In the present review we discuss current knowledge about the role of the plant growth hormones abscisic acid, auxin, brassinosteroid and ethylene in signaling pathways, defense mechanisms and alleviation of heavy metal toxicity.

  7. Increasing the reliability of electric energy supply to consumers in ROMAG-PROD Heavy Water Plant

    International Nuclear Information System (INIS)

    Barta, Ioan; Hanes, Marian . E-mail electrica@romag.ro

    2004-01-01

    Full text: This work aims at achieving an analysis of time evolution of the status of electrical installations, their performances and reliability, at describing the refurbishment measures adopted, at assessing the efficiency of these measures and also to suggest solutions for improving the reliability in the electric energy supply of ROMAG-PROD Heavy Water Plant. The analysis started from the original design, the manner the electrical installations were mounted, the technological level of this equipment and gives an evaluation of the deficiencies and the evolution of incidents occurred during the operation period. On the basis of the experience gathered one advances new items for equipment renewing and refurbishment of electric installations which together with the existing ones would ensure an electric energy supply more secure and efficient, leading directly to a more safe and efficient operation of the ROMAG-PROD Heavy Water Plant. In this work the incidents of electric energy nature which occurred are analyzed, the equipment which generated events identified and measures to solve these problems proposed

  8. Use of steam condensate exchange process for recovery of deuterium from condensate of ammonia plant as adopted at Heavy Water Plant, Talcher (Paper No. 2.5)

    International Nuclear Information System (INIS)

    Saha, S.; Saha, P.

    1992-01-01

    This paper highlights the use of steam-condensate exchange system for recovery of deuterium from condensate of ammonia plant, which is adopted at Heavy Water Plant, Talcher. Deuterium concentration in the condensate leaving the steam-condensate exchange column can be brought down very close to the deuterium concentration in water thereby achieving practically complete deuterium recovery. (author). 2 tabs., 1 fig

  9. Nuclear generating station and heavy water plant cost estimates for strategy studies

    International Nuclear Information System (INIS)

    Archinoff, G.H.

    1979-07-01

    Nuclear generating station capital, operating and maintenance costs are basic input data for strategy analyses of alternate nuclear fuel cycles. This report presents estimates of these costs for natural uranium CANDU stations, CANDU stations operating on advanced fuel cycles, and liquid metal fast breeder reactors. Cost estimates for heavy water plants are also presented. The results show that station capital costs for advanced fuel cycles are not expected to be significantly greater than those for natural uranium stations. LMFBR capital costs are expected to be 25-30 percent greater than for CANDU's. (auth)

  10. Interactions between plant hormones and heavy metals responses

    Directory of Open Access Journals (Sweden)

    Lauro Bücker-Neto

    2017-04-01

    Full Text Available Abstract Heavy metals are natural non-biodegradable constituents of the Earth's crust that accumulate and persist indefinitely in the ecosystem as a result of human activities. Since the industrial revolution, the concentration of cadmium, arsenic, lead, mercury and zinc, amongst others, have increasingly contaminated soil and water resources, leading to significant yield losses in plants. These issues have become an important concern of scientific interest. Understanding the molecular and physiological responses of plants to heavy metal stress is critical in order to maximize their productivity. Recent research has extended our view of how plant hormones can regulate and integrate growth responses to various environmental cues in order to sustain life. In the present review we discuss current knowledge about the role of the plant growth hormones abscisic acid, auxin, brassinosteroid and ethylene in signaling pathways, defense mechanisms and alleviation of heavy metal toxicity.

  11. 1000 tones of heavy water produced at ROMAG PROD, Drobeta-Turnu Severin

    International Nuclear Information System (INIS)

    2001-01-01

    On May 25, 2001 the heavy water plant ROMAG PROD at Drobeta-Turnu Severin recorded the production of the 1000-th tone of nuclear purity heavy water. The heavy water plant ROMAG PROD makes use of a technology based on the results of isotopic deuterium separation research carried out at the Research and Design Institutes of Cluj, Craiova, Pitesti and Ploiesti during 1957-1970 and the separation technology tested at Ramnicu-Valcea pilot plant (at present the Cryogenics and Isotope Separation Institute). The first investments at ROMAG PROD were made in 1979 and on July 17, 1988 was produced the first amount of heavy water at the required parameters for CANDU type nuclear reactors. The period between 1990-1992 was dedicated to the project completion, upgrading the technological facilities and retrofitting the environmental protection and monitoring systems. Production was resumed in 1992. The first 500 t of heavy water required for the Cernavoda NPP first reactor operation were produced by summer 1997. The additional amount of 500 t of heavy water was produced between 1997-2001. ROMAG PROD obtained the ISO 9001/2001 certificate for the quality management system, the ISO 14001/1997 certificate for the environmental management system and the new environmental permit

  12. Heavy water at Aswan

    International Nuclear Information System (INIS)

    1959-01-01

    A fertilizer factory is being built by Egyptian Chemical Industries (Kima) at Aswan on the upper Nile; it will produce a mixture of ammonium nitrate and calcium carbonate adjusted to contain 20.5% nitrogen. It is also proposed to construct a heavy water plant to be located at and integrated with the fertilizer factory. At the request of the Government of the United Arab Republic, the International Atomic Energy Agency sent an expert to carry out investigation of the technical, economic and other related aspects of the proposed production of heavy water. A report was submitted to the IAEA Director General. Its main conclusions can be summarized as follows: (1) Production of heavy water as a by-product of fertilizer manufacture at Aswan is technically feasible. Separation of deuterium from industrial hydrogen for this purpose could be done either by catalytic exchange or by liquefaction and distillation; the choice should depend on economic considerations. (2) The heavy water produced at Aswan should be competitive in cost with that produced elsewhere; this, however, would depend on whether firm contracts are obtained for the delivery of equipment at guaranteed prices and with guaranteed performance, and whether such prices are in reasonable agreement with preliminary estimates. (3) The future market for heavy water is difficult to predict. For one thing, there is a very large production capacity in the USA, most of which is idle due to lack of demand. Secondly, there is a relatively small production outside the USA that is sold at prices higher than that charged by the US Government. The future of the market is necessarily contingent upon the possibility of future free sale by the US Government. At the end of his report, the expert has also given his comments on possible further assistance to the project by IAEA

  13. Heavy water upgrading system in the Fugen heavy water reactor

    International Nuclear Information System (INIS)

    Matsushita, T.; Susaki, S.

    1980-01-01

    The heavy water upgrading system, which is installed in the Fugen heavy water reactor (HWR) was designed to reuse degraded heavy water generated from the deuteration-dedeuteration of resin in the ion exchange column of the moderator purification system. The electrolysis method has been applied in this system on the basis of the predicted generation rate and concentration of degraded heavy water. The structural feature of the electrolytic cell is that it consists of dual cylindrical electrodes, instead of a diaphragm as in the case of conventional water electrolysis. 2 refs

  14. Drying of heavy water system and works of charging heavy water in Fugen

    International Nuclear Information System (INIS)

    Matsushita, Tadashi; Iijima, Setsuo

    1980-01-01

    The advanced thermal reactor ''Fugen'' is the first heavy water-moderated, boiling light water-cooled nuclear reactor for power generation in Japan. It is a large heavy water reactor having about 130 m 3 of heavy water inventory and about 300 m 3 of helium space as the cover gas of the heavy water system. The heavy water required was purchased from FRG, which had been used for the power output test in the KKN, and the quality was 99.82 mol % mean heavy water concentration. The concentration of heavy water for Fugen used for the nuclear design is 99.70 mol%, and it was investigated how heavy water can be charged without lowering the concentration. The matters of investigation include the method of bringing the heavy water and helium system to perfect dryness after washing and light water test, the method of confirming the sufficient dryness to prevent the deterioration, and the method of charging heavy water safely from its containers. On the basis of the results of investigation, the actual works were started. The works of drying the heavy water and helium system by vacuum drying, the works of sampling heavy water and the result of the degree of deterioration, and the works of charging heavy water and the measures to the heavy water remaing in the containers are described. All the works were completed safely and smoothly. (J.P.N.)

  15. Operating experiences of gas purification system of Heavy Water Plant Talcher (Paper No. 1.11)

    International Nuclear Information System (INIS)

    Bhattacharya, R.; Mohanty, P.R.; Pandey, B.L.

    1992-01-01

    The operating experiences with the purification system installed at Heavy Water Plant, Talcher for purification of feed synthesis gas from fertilizer plant is described. The purification system has performed satisfactorily even with levels of impurities as much as 15 to 20 ppm of oxygen and carbon monoxide. The system could not however be tested at designed gas throughput and on a sustained basis. However, increase in gas throughput upto the design value is not expected to pose any problem on the performance of the purification system. (author). 5 figs

  16. Programmable logic controllers in Heavy Water Project, Manuguru (Paper No. 3.4)

    International Nuclear Information System (INIS)

    Gupta, S.C.; Bhaskar, R.; Maiti, A.; Venkatesu, G.; Satish, P.; Goel, R.K.

    1992-01-01

    Enhancement to plant operational flexibility has been achieved in Heavy Water Project, Manuguru by installing programmable logic controllers for its control equipment. The earlier sulfide based Heavy Water Plant, Kota is using relay logic and diode based program-matrix for binary controls. Performance improvement and advantages of PLC and experience in its operation are described. (author). 3 refs

  17. Heavy water cycle in the CANDU reactor

    International Nuclear Information System (INIS)

    Nanis, R.

    2000-01-01

    Hydrogen atom has two isotopes: deuterium 1 H 2 and tritium 1 H 3 . The deuterium oxide D 2 O is called heavy water due to its density of 1105.2 Kg/m 3 . Another important physical property of the heavy water is the low neutron capture section, suitable to moderate the neutrons into natural uranium fission reactor as CANDU. Due to the fact that into this reactor the fuel is cooled into the pressure tubes surrounded by a moderator, the usage of D 2 O as primary heat transport (PHT) agent is mandatory. Therefore a large amount of heavy water (approx. 500 tons) is used in a CANDU reactor. Being a costly resource - it represents 20% of the initial plant capital cost, D 2 O management is required to preserve it. (author)

  18. Chemistry in production of heavy water and industrial solvents

    International Nuclear Information System (INIS)

    Thomas, P.G.

    2015-01-01

    Industries are the temples of modern science built on the robust foundation of science and technology. The genesis of giant chemical industries is from small laboratories where the scientific thoughts are fused and transformed into innovative technologies Heavy water production is an energy intensive giant chemical industry where various hazardous and flammable chemicals are handled, extreme operating conditions are maintained and various complex chemical reactions are involved. Chemistry is the back bone to all chemical industrial activities and plays a lead role in heavy water production also. Heavy Water Board has now mastered the technology of design, construction, operation and maintenance of Heavy Water plants as well as fine tuning of the process make it more cost effective and environment friendly. Heavy Water Board has ventured into diversified activities intimately connected with our three stages of Nuclear Power Programme. Process development for the production of nuclear grade solvents for the front end and back end of our nuclear fuel cycle is one area where we have made significant contributions. Heavy Water Board has validated, modified and fine-tuned the synthesis routes for TBP, D2EHPA, TOPO, TAPO TIAP, DNPPA, D2EHPA-II, DHOA etc and these solvents were accepted by end users. Exclusive campaigns were carried out in laboratory scale, bench scale and pilot plant scale before scaling up to industrial scale. The process chemistry is understood very well and chemical parameters were monitored in every step of the synthesis. It is a continual improvement cycle where fine tuning is carried out for best quality and yield of product at lowest cost. In this presentation, an attempt is made to highlight the role of chemistry in the production of Heavy Water and industrial solvents

  19. The projects for heavy water production of the Argentine National Atomic Energy Commission

    International Nuclear Information System (INIS)

    Garcia Bourg, J.M.; Garcia, E.E.

    1982-01-01

    The bases and scope of the projects for heavy water production that are being currently developed by the Argentine National Atomic Energy Commission (CNEA) are described. As an introduction, the following points are presented: a) the fundamentals of heavy water utilization in a nuclear reactor, with a mention of its properties and uses, b) a review of the physicochemical bases of the principal methods for heavy water production: chemical exchange (monothermal and bithermal processes), distillation and electrolysis, with tables summarizing the fundamental characteristics of the first two ones, and an evaluation of the different production methods from the viewpoint of their application in an industrial scale; and c) a synthetic information, in the form of tables, about the world's heavy water production. The subject of heavy water production in Argentina is treated in the principal section, describing the scope, location, main characteristics and chemical processes corresponding to the projects being developed by CNEA, which currently are the installation of an Industrial Plant in Arroyito (Province of Neuquen), purchased on a turnkey basis and using the NH 3 /H 2 isotopic exchange method; the installation of an Experimental Plant in Atucha (Province of Buenos Aires), for the development of the domestic technology of heavy-water production by the SH 2 /H 2 O isotopic exchange method, and the development of the engineering of an industrial plant (''Module 80''), based on the Experimental Plant's technology. (M.E.L.) [es

  20. Evaluation of heavy metal pollution in water wells and soil using common leafy green plant indicators in the Al-Kharj region, Saudi Arabia.

    Science.gov (United States)

    Al-Hammad, Bushra Ahmed; Abd El-Salam, Magda Magdy

    2016-06-01

    This study was performed to determine the levels of eight heavy metals in irrigation well water and soil and to assess the suitability of some leafy green plants that are commonly cultivated in the Al-Kharj region, Saudi Arabia, for human consumption using an atomic absorption spectrometer. The mean concentrations of metals ranged from 0.0001 to 0.436 mg/L in well water and from 0.248 to 164.52 mg/kg in soil. The heavy metal concentrations showed significant differences among the different leafy green plants studied. Parsley (4.98 mg/kg) exhibited higher levels of Pb than other leafy green plants, whereas mallow (0.097 mg/kg) revealed greater amounts of Cd than other plants. All of the leafy green plants retained essential metals (Cu, Zn, Fe and Mn) more than the toxic metals (Pb and Cd). The levels of some of the metals in the leafy green plants were found to meet the FAO/WHO-recommended limits. The monitoring of heavy metals in leafy green plants must be continued because these plants are the main source of food for humans in many parts of the world and are considered to be bio-indicators for environmental pollution.

  1. Manufacturing opportunities in the Canadian CANDU and heavy water programs

    International Nuclear Information System (INIS)

    Reny, J.P.

    The volume of business available to Canadian manufacturers of CANDU power plant and heavy water plant components is analyzed over about the next 10 years. Implications of exported nuclear technology and plants are explored. (E.C.B.)

  2. Deuterium and heavy water

    International Nuclear Information System (INIS)

    Vasaru, G.; Ursu, D.; Mihaila, A.; Szentgyorgyi, P.

    1975-01-01

    This bibliography on deuterium and heavy water contains 3763 references (1932-1974) from 43 sources of information. An author index and a subject index are given. The latter contains a list of 136 subjects, arranged in 13 main topics: abundance of deuterium , catalysts, catalytic exchange, chemical equilibria, chemical kinetics, deuterium and heavy water analysis, deuterium and heavy water properties, deuterium and heavy water separation, exchange reactions, general review, heavy water as moderator, isotope effects, synthesis of deuterium compounds

  3. Heavy water GS process R and D achievements

    International Nuclear Information System (INIS)

    Bancroft, A.R.

    1978-10-01

    R and D support of Canadian heavy water production plants during the past five years has involved mainly AECL and Ontario Hydro, and their contractors. Testing has been done in the production plants, in two pilot plants and in research laboratories on topics that include sieve tray design, in-plant behaviour of oil and sulfur and choice of antifoam agent to control excessive foaming. The benefits are increased production through higher plant flows and higher extraction of deuterium from the feed, less down time because of process problems and lower cost for materials used to control water chemistry. (author)

  4. Concentration of heavy metals in brook trout in comparison to aquatic plants and sediments

    Energy Technology Data Exchange (ETDEWEB)

    Abo-Rady, M.D.

    1983-01-01

    From 1974 to 1977 the heavy metal content of river water, fishes (Salmo trutta fario), three aquatic plants (Cladophora glomerata, Potamogeton pectinatus, Zannichellia palustris), one river-bank plant (Phalaris arundinacea), and sediments (clay fraction) taken from the River Leine, up and downstream of Goettingen, were determined. Galvanic-bath sewage containing heavy metals caused an increase (11-60%) in the concentration of nine elements in the water. The average level of heavy metals in the river water corresponded to that of the Ems, Elbe and Weser, but was lower than that of the Neckar, Rhine and Danube. It was also below the European Community Guidelines (1975) on the quality of water used for the artificial recharging of ground water. River water upstream of the city has been used for this recharging for many years. There is a good correlation between the metal content in the investigated samples and in the water. In the muscles, only Cd, Co and Mn, in the liver Cd, Co, Cr. Hg, Mn and Zn, and in the total fish Cd, Co, Cr, Cu and Zn had increased significantly. In contrast to all other elements, Cr shows the highest concentration in the muscles. A previous accumulation of Cr in the liver is not a prerequisite for the accumulation in the muscles. Mercury shows the highest accumulation in the muscles, apparently because of the high retention rate of this element. Muscles also are a good monitor for this element. The impact of heavy metals on the Leine water was reflected in aquatic plants, which showed an increase in concentration up to 95-fold (according to metal or plant) - but not in river-bank plants. C. glomerata has the remarkable capability of accumulating all ten elements. Since P. arundinacea cannot reflect the different load of heavy metals it is therefore less suitable as a biological monitor for these metals.

  5. Pre-commissioning activities of exchange units of Heavy Water Plant, Manuguru (Paper No. 1.2)

    International Nuclear Information System (INIS)

    Kamath, H.S.; Sikaria, R.P.

    1992-01-01

    Heavy Water Plant, Manuguru (HWPM) comprises of two exchange units where enrichment of deuterium from natural concentration to 15% concentration is achieved using dual temperature H 2 S-H 2 O exchange process in a three stage cascade. In each exchange unit an inventory of around 200 MT of H 2 S gas is required under normal operating pressure and a feed water flow rate of 450 MT/Hr is required to be maintained. In view of the large flow rates of H 2 S circulating gas, water, cooling water, steam etc., the lines sizes in exchange unit are quite large. Further, H 2 S gas being highly toxic and corrosive, extreme care is required in order to ensure integrity and leak tightness. While due care is taken in material selection, design, quality surveillance etc., during fabrication, certain additional measures are required to be taken during precommissioning of the systems handling H 2 S under pressure. This paper deals with the activities from completion of plant erection including hydrotesting of piping by the piping contractor to the stage of trial production run. (author)

  6. AECB staff annual assessment of the Bruce Heavy Water Plant for the year 1994

    International Nuclear Information System (INIS)

    1995-06-01

    This report is the Atomic Energy Control Board staff assessment of the operation of Bruce Heavy Water Plant (BHWP) during 1994. BHWP operation was acceptably safe in 1994. At BHWP, Ontario Hydro did not breach any of the regulations issued under the authority of the Atomic Energy Control Act. There were four minor violations of the BHWP Operating Licence. In all cases, Ontario Hydro exceeded Ontario Hydro government limits for releases to the environment. None of the events threatened public health or the environment. 2 figs

  7. Heavy metal contamination and risk assessment in water, paddy soil, and rice around an electroplating plant.

    Science.gov (United States)

    Liu, Jie; Zhang, Xue-Hong; Tran, Henry; Wang, Dun-Qiu; Zhu, Yi-Nian

    2011-11-01

    The objective of this paper is to assess the impact of long-term electroplating industrial activities on heavy metal contamination in agricultural soils and potential health risks for local residents. Water, soil, and rice samples were collected from sites upstream (control) and downstream of the electroplating wastewater outlet. The concentrations of heavy metals were determined by an atomic absorption spectrophotometer. Fractionation and risk assessment code (RAC) were used to evaluate the environmental risks of heavy metals in soils. The health risk index (HRI) and hazard index (HI) were calculated to assess potential health risks to local populations through rice consumption. Hazardous levels of Cu, Cr, and Ni were observed in water and paddy soils at sites near the plant. According to the RAC analysis, the soils showed a high risk for Ni and a medium risk for Cu and Cr at certain sites. The rice samples were primarily contaminated with Ni, followed by Cr and Cu. HRI values >1 were not found for any heavy metal. However, HI values for adults and children were 2.075 and 1.808, respectively. Water, paddy soil, and rice from the studied area have been contaminated by Cu, Cr, and Ni. The contamination of these elements is related to the electroplating wastewater. Although no single metal poses health risks for local residents through rice consumption, the combination of several metals may threaten the health of local residents. Cu and Ni are the key components contributing to the potential health risks.

  8. CANDU - Canadian experience and expectations with the heavy-water reactor

    International Nuclear Information System (INIS)

    Foster, J.S.; Russell, S.H.

    1977-05-01

    The paper describes the evolution of the CANDU nuclear-power plants with particular reference to the objectives of safety, reliability and economy; the development of industrial capacity for the supply of fuel, components and heavy water; and the prospective development of advanced fuel cycles and the projected results. It provides data on radiation, releases, and exposures, internal and external to the power plants; plant availability, capacity factors and other performance data; heavy water production data with reference to safety, reliability, and economics; projections of the performance of CANDU reactors operating on a thorium-U-233 cycle and the development required to establish this cycle; and intent with respct to spent-fuel management and radioactive-waste storage. (author)

  9. Heavy water upgrader of 'Fugen'

    International Nuclear Information System (INIS)

    Matsushita, Tadashi; Sasaki, Shigeo

    1980-01-01

    The nuclear power station of the advanced thermal prototype reactor ''Fugen'' has continued the smooth operation since it started the fullscale operation in March, 1979. Fugen is the first heavy water-moderated, boiling light water-cooled reactor in Japan, and its outstanding feature is the use of heavy water as the moderator. The quantity of heavy water retained in Fugen is about 140 m 3 , and the concentration is 99.8 wt.%. This heavy water had been made is USA, and was imported from F.R. of Germany where it had been used. Heavy water is an internationally regulated material, and it is very expensive and hard to purchase. Therefore in order to prevent the deterioration of heavy water and to avoid its loss as far as possible, the management of the quantity and the control of the water quality have been carried out carefully and strictly. The generation of deteriorated heavy water occurs from the exchange of ion exchange resin for poison removal and purification. The heavy water upgrader reconcentrates the deteriorated heavy water of high concentration and returns to the heavy water system, and it was installed for the purpose of reducing the purchase of supplementary heavy water. The outline of the heavy water upgrader, its construction, the performance test and the operation are described. (Kako, I.)

  10. High purity heavy water production: need for total organic carbon determination in process water streams

    International Nuclear Information System (INIS)

    Ayushi; Kumar, Sangita D.; Reddy, A.V.R.; Vithal, G.K.

    2009-01-01

    In recent times, demand for high purity heavy water (99.98% pure) in industries and laboratories has grown by manifold. Its application started in nuclear industry with the design of CANDU reactor, which uses natural uranium as fuel. In this reactor the purest grade of heavy water is used as the moderator and the primary coolant. Diverse industrial applications like fibre optics, medicine, semiconductors etc. use high purity heavy water extensively to achieve better performance of the specific material. In all these applications there is a stringent requirement that the total organic carbon content (TOC) of high purity heavy water should be very low. This is because the presence of TOC can lead to adverse interactions in different applications. To minimize the TOC content in the final product there is a need to monitor and control the TOC content at each and every stage of heavy water production. Hence a simple, rapid and accurate method was developed for the determination of TOC content in process water samples. The paper summarizes the results obtained for the TOC content in the water samples collected from process streams of heavy water production plant. (author)

  11. Control and monitoring of H2S in environments of Heavy Water Plant (Kota) (Paper No. 4.5)

    International Nuclear Information System (INIS)

    Hiremath, S.C.; Unni, V.K.R.

    1992-01-01

    Heavy Water Plant (Kota) utilizes dual temperature exchange process of hydrogen sulphide and water for extracting deuterium from water upto 15% and vacuum distillation process for enriching it from 15 to 99.8%. H 2 S gas is used in large quantities as a carrier gas to extract the deuterium content of water. The safe handling of large quantities of H 2 S gas poses a major problem. The properties of H 2 S gas are : high toxicity, high corrosive nature, high flammability and explosiveness. To overcome these properties all safety aspects have been considered while designing, fabricating, constructing and operating the plant and a number of design safety features have been incorporated in the systems. Some of the typical unusual occurrences happened have also been described. (author)

  12. Analysis of Piping Systems for Life Extension of Heavy Water Plants in India

    International Nuclear Information System (INIS)

    Mishra, Rajesh K.; Soni, R.S.; Kushwaha, H.S.; Raj, V. Venkat

    2002-01-01

    Heavy water production in India has achieved many milestones in the past. Two of the successfully running heavy water plants are on the verge of completion of their design life in the near future. One of these two plants, situated at Kota, is a hydrogen sulfide based plant and the other one at Tuticorin is an ammonia-based plant. Various exercises have been planned with an aim to assess the fatigue usage for the various components of these plants in order to extend their life. Considering the process parameters and the past history of the plant performance, critical piping systems and equipment are identified. Analyses have been carried out for these critical piping systems for mainly two kinds of loading, viz. sustained loads and the expansion loads. Static analysis has been carried out to find the induced stress levels due to sustained as well as thermal expansion loading as per the design code ANSI B31.3. Due consideration has been given to the design corrosion allowance while evaluating the stresses due to sustained loads. At the locations where the induced stresses (S L ) due to the sustained loads are exceeding the allowable limits (S h ), exercises have been carried out considering the reduced corrosion allowance value. This strategy is adopted in view of the fact that the thickness measurements carried out at site at various critical locations show a very low rate of corrosion. It has been possible to qualify the system with reduced corrosion allowance values however, it is recommended to keep that location under periodic monitoring. The strategy adopted for carrying out analysis for thermal expansion loading is to qualify the system as per the code allowable value (S a ). If the stresses are more than the allowable value, credit of liberal allowable value as suggested in the code i.e., with the addition of the term (S h -S L ) to the term 0.25 S h , has been taken. However, if at any location, it is found that thermal stress is high, fatigue analysis has

  13. Implementation of requirements of environmental management (ISO 14000) for the decommissioning of the heavy water plant

    International Nuclear Information System (INIS)

    Gonzalez, Maria I.; Otero de Eppenstein, Marta; Tosi, Lidia E.; Sabio, Manuel

    2000-01-01

    The National Atomic Energy Commission (CNEA) of Argentina has a project of decommissioning in the heavy water plant (Planta Experimental de Agua Pesada - PEAP). The aim of this project is to get some experience for decommissioning of nuclear plants and to achieve knowledge about the application of the requirements in environmental management. The project is being carried out according to ISO 14001 standards 'Environmental Management Systems'. The objectives were taken from the model without any expectation of achieving the complete implementation or certification of the system. This report is a description of the acts that have been done. (author)

  14. AECB staff annual assessment of the Bruce Heavy Water Plant for the year 1995

    International Nuclear Information System (INIS)

    1996-06-01

    The Atomic Energy Control Board's staff annual assessment of the operation of Bruce Heavy Water Plant (BHWP) during 1995. BHWP operation was acceptably safe in 1995. At BHWP, Ontario Hydro complied with the regulations issued under the authority of the Atomic Energy Control Act. AECB is satisfied that BHWP did not pose any undue risk to public health or safety or to the environment. Ontario Hydro met all safety system and safety related system availability targets at BHWP in 1995. The emergency response capability is satisfactory. 2 figs

  15. Heavy water. An original project in the Argentine Patagonia

    International Nuclear Information System (INIS)

    Conde Bidabehere, Luis F.

    2000-01-01

    The history of the heavy water production plant built in Arroyito, in the Argentine province of Neuquen is related. Details are given on the development of the project and on the operation of the plant. The possible complementary production of ammonia and fertilizers is analyzed

  16. Canned motor pumps at Heavy Water Project, Baroda

    International Nuclear Information System (INIS)

    Batra, R.K.; Waishampayan, S.C.

    1981-01-01

    Pumps to be used in heavy water plants must be reliable and should require negligible maintenance, because most of them are totally unapproachable under normal circumstances. Canned motor pumps fulfil these requirements. Their design features are described briefly. The details of: (1) the pumps in the isotopic exchange tower and (2) pumps for liquid ammonia and catalyst are given. Problems faced during commissioning of such pumps in Baroda Heavy Water Project were bulging of rotors of tower pumps, bulging of stators, jamming and failure of bearings. Solution of these problems is described. (M.G.B.)

  17. Optimization of the operational parameters in isotopic exchange installations. ROMAG PROD plant production of heavy water for the nuclear power plant

    International Nuclear Information System (INIS)

    Pop, A.

    2002-01-01

    The ROMAG PROD heavy water plant at Drobeta Turnu Severin together with SN Nuclearelectrica Company and Nuclear Fuel Plant at Pitesti are the most important pillars the National Nuclear Program is based on. The plant became operational on 17th July 1988, was later modernized and now reached in the field a leading position known world wide. There are described the modifications adopted to the two stages of the isotopic exchange installation besides some refurbishment measures of general character. The increase of discharge flow rate in cool columns vs hot columns resulted in a rise of technological regime stability and the feeding rate. Also in the first stage the stripping vapor injection in the hot columns was modified to avoid vacuum excursion in the columns. In the second stage two isotopic exchange trays were replaced with dry trays to obtain drop separation at the cool column top. All the trays from the isotopic exchange section of the cool column were replaced by trays from the hot column. The thermal exchange zone in the cool column was modified by introducing trays with number of holes. The gas flow rate of the stage two compressor was adapted to the design requirements. By these changes of the parameters in the original design were substantially improved, the operation became easier, more secure and safer for the environment while the production of the heavy water doubled between 1995 and 2001 reaching a value of 163 t/y in 2001

  18. Safety and environmental aspects of heavy water production (Paper No. 4.1)

    International Nuclear Information System (INIS)

    Singh, Mohinder

    1992-01-01

    Different processes are utilised for heavy water production in the heavy water plants in India. H 2 S is used in large quantities as carrier gas to extract deuterium content from water. The safe handling of such large quantities of H 2 S gas poses a major problem because of its toxicity, high corrosive nature and high flammability. Handling of large quantities of synthesis gas in ammonia based plants at high pressure and temperature poses a major problem because it is a mixture of hydrogen and nitrogen. H 2 is highly inflammable and explosive when mixed with air or oxygen. All the safety aspects considered while designing, fabricating, constructing and operating the plants are described. (author). 5 tabs

  19. Analysis of hydrogen sulfide releases in heavy water production facilities

    International Nuclear Information System (INIS)

    Croitoru, Cornelia; Dumitrescu, Maria; Preda, Irina; Lazar, Roxana

    1996-01-01

    Safety analyses conducted at ICIS concern primarily the heavy water production installations. The quantitative risk assessment needs the frequency calculation of accident sequences and consequences. In heavy water plants which obtain primary isotopic concentration of water by H 2 O - H 2 S exchange, large amounts of hydrogen sulfide which is a toxic, inflammable and explosive gas, are circulated. The first stage in calculating the consequences consists in potential analysis of H 2 S release. This work presents a study of this types of releases for pilot installations of the heavy water production at ICIS (Plant 'G' at Rm. Valcea). The installations which contain and maneuver large quantities of H 2 S and the mathematical models for different types of releases are presented. The accidents analyzed are: catastrophic column, container, spy-hole failures or gas-duct rupture and wall cracks in the installation. The main results are given as tables while the time variations of the flow rate and quantities of H 2 O released by stack disposal are plotted

  20. A review of the UKAEA interest in heavy water reactors

    International Nuclear Information System (INIS)

    Symes, R.J.

    1983-01-01

    The chapter commences with a brief account of the history of heavy water production and then begins the story of the British use of this moderator in power reactors. This is equated with the introduction and development of the tube reactor as a distinct and important form of reactor construction in contrast with the perhaps better known vessel design that has tended to dominate reactor engineering to date. The account thus includes a succession of reactor designs including the gas and steam cooled heavy water systems in addition to the steam-generating heavy water reactor. The SGHWR was demonstrated by the construction of a substantial prototype, which continues in operation as a flexible and reliable electricity-generating plant. It was also, for a time, identified as the system to be used for Britain's third reactor programme. Today the successful Canadian CANDU power reactors represent the only penetration of heavy water reactor technology into large scale electricity generation. The range of research and experimental reactors using heavy water in their cores is reviewed. (author)

  1. The future 700 MWe pressurized heavy water reactor

    International Nuclear Information System (INIS)

    Bhardwaj, S.A.

    2006-01-01

    The design of a 700 MWe pressurized heavy water reactor has been developed. The design is based on the twin 540 MWe reactors at Tarapur of which the first unit has been made critical in less than 5 years from construction commencement. In the 700 MWe design boiling of the coolant, to a limited extent, has been allowed near the channel exit. While making the plant layout more compact, emphasis has been on constructability. Saving in capital cost of about 15%, over the present units, is expected. The paper describes salient design features of 700 MWe pressurized heavy water reactor

  2. Design considerations for application of shunt capacitors in Heavy Water Plant (Tuticorin) (Paper No. 5.8)

    International Nuclear Information System (INIS)

    Subramanian, A.R.; Palani, R.A.A.; Thomson, J.

    1992-01-01

    The average load requirement of Heavy Water Plant, Tuticorin was 11.13 MVA with the power factor of 0.86, the calculated KVAR rating was 5,600. To improve the power factor from 0.86 to 0.98 the reactive compensation calculated was around 4200 KVAR. Accordingly a new 3.3 K.V. 4200 KVAR auto switching capacitor bank was installed at HWP(T) for power factor improvement. The paper describes the design considerations of the capacitor bank. (author)

  3. Heavy metal tolerance in plants: Role of transcriptomics, proteomics, metabolomics and ionomics

    Directory of Open Access Journals (Sweden)

    Samiksha eSingh

    2016-02-01

    Full Text Available Heavy metal contamination of soil and water causing toxicity/stress has become one important constraint to crop productivity and quality. This situation has further worsened by the increasing population growth and inherent food demand. It have been reported in several studies that counterbalancing toxicity, due to heavy metal requires complex mechanisms at molecular, biochemical, physiological, cellular, tissue and whole plant level, which might manifest in terms of improved crop productivity. Recent advances in various disciplines of biological sciences such as metabolomics, transcriptomics, proteomics etc. have assisted in the characterization of metabolites, transcription factors, stress-inducible proteins involved in heavy metal tolerance, which in turn can be utilized for generating heavy metal tolerant crops. This review summarizes various tolerance strategies of plants under heavy metal toxicity, covering the role of metabolites (metabolomics, trace elements (ionomics, transcription factors (transcriptomics, various stress-inducible proteins (proteomics as well as the role of plant hormones. We also provide a glance at strategies adopted by metal accumulating plants also known as metallophytes.

  4. Heavy Metal Tolerance in Plants: Role of Transcriptomics, Proteomics, Metabolomics, and Ionomics

    Science.gov (United States)

    Singh, Samiksha; Parihar, Parul; Singh, Rachana; Singh, Vijay P.; Prasad, Sheo M.

    2016-01-01

    Heavy metal contamination of soil and water causing toxicity/stress has become one important constraint to crop productivity and quality. This situation has further worsened by the increasing population growth and inherent food demand. It has been reported in several studies that counterbalancing toxicity due to heavy metal requires complex mechanisms at molecular, biochemical, physiological, cellular, tissue, and whole plant level, which might manifest in terms of improved crop productivity. Recent advances in various disciplines of biological sciences such as metabolomics, transcriptomics, proteomics, etc., have assisted in the characterization of metabolites, transcription factors, and stress-inducible proteins involved in heavy metal tolerance, which in turn can be utilized for generating heavy metal-tolerant crops. This review summarizes various tolerance strategies of plants under heavy metal toxicity covering the role of metabolites (metabolomics), trace elements (ionomics), transcription factors (transcriptomics), various stress-inducible proteins (proteomics) as well as the role of plant hormones. We also provide a glance of some strategies adopted by metal-accumulating plants, also known as “metallophytes.” PMID:26904030

  5. Heavy metals in contaminated environment: Destiny of secondary metabolite biosynthesis, oxidative status and phytoextraction in medicinal plants.

    Science.gov (United States)

    Asgari Lajayer, Behnam; Ghorbanpour, Mansour; Nikabadi, Shahab

    2017-11-01

    Contamination of soils, water and air with toxic heavy metals by various human activities is a crucial environmental problem in both developing and developed countries. Heavy metals could be introduced into medicinal plant products through contaminated environment (soil, water and air resources) and/or poor production practices. Growing of medicinal plants in heavy metal polluted environments may eventually affect the biosynthesis of secondary metabolites, causing significant changes in the quantity and quality of these compounds. Certain medicinal and aromatic plants can absorb and accumulate metal contaminants in the harvestable foliage and, therefore, considered to be a feasible alternative for remediation of polluted sites without any contamination of essential oils. Plants use different strategies and complex arrays of enzymatic and non-enzymatic anti-oxidative defense systems to cope with overproduction of ROS causes from the heavy metals entered their cells through foliar and/or root systems. This review summarizes the reports of recent investigations involving heavy metal accumulation by medicinal plants and its effects on elicitation of secondary metabolites, toxicity and detoxification pathways, international standards regarding in plants and plant-based products, and human health risk assessment of heavy metals in soil-medicinal plants systems. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Heavy water and nonproliferation

    International Nuclear Information System (INIS)

    Miller, M.M.

    1980-05-01

    This report begins with a historical sketch of heavy water. The report next assesses the nonproliferation implications of the use of heavy water-moderated power reactors; several different reactor types are discussed, but the focus is on the natural uranium, on-power fueled, pressure tube reactor CANDU. The need for and development of on-power fueling safeguards is discussed. Also considered is the use of heavy water in plutonium production reactors as well as the broader issue of the relative nuclear leverage that suppliers can bring to bear on countries with natural uranium-fueled reactors as compared to those using enriched designs. The final chapter reviews heavy water production methods and analyzes the difficulties involved in implementing these on both a large and a small scale. It concludes with an overview of proprietary and nonproliferation constraints on heavy water technology transfer

  7. Improvement in fuel utilization in pressurized heavy water reactors due to increased heavy water purity

    International Nuclear Information System (INIS)

    Balakrishnan, M.R.

    1991-01-01

    This paper reports that in a pressurized heavy water reactor (PHWR), the reactivity of the reactor and, consequently, the discharge burnup of the fuel depend on the isotopic purity of the heavy water used in the reactor. The optimal purity of heavy water used in PHWRs, in turn, depends on the cost of fabricated uranium fuel and on the incremental cost incurred in improving the heavy water purity. The physics and economics aspects of the desirability of increasing the heavy water purity in PHWRs in India were first examined in 1978. With the cost data available at that time, it was found that improving the heavy water purity from 99.80% to 99.95% was economically attractive. The same problem is reinvestigated with current cost data. Even now, there is sufficient incentive to improve the isotopic purity of heavy water used in PHWRs. Admittedly, the economic advantage that can be derived depends on the cost of the fabricated fuel. Nevertheless, irrespective of the economics, there is also a fairly substantial saving in natural uranium. That the increase in the heavy water purity is to be maintained only in the low-pressure moderator system, and not in the high-pressure coolant system, makes the option of achieving higher fuel burnup with higher heavy water purity feasible

  8. On-line infrared heavy-water instruments: status, economics and prospects

    International Nuclear Information System (INIS)

    Lynch, G.F.

    1978-06-01

    An intensive program to rehabilitate and establish the reliability of on-line heavy-water monitors is now showing tangible results. After determining the operating specifications and characteristics of the infrared D 2 O analyzers manufactured by Barringer Research Limited, monitoring systems based on these instruments were installed and commissioned at reactors and heavy-water plants. Ten such systems are currently operating reliably in the field. Laboratory tests and field experience have identified design features which would make the analyzers more convenient to use and less sensitive to environmental conditions. The conceptual design of a new instrument which is less dependent on station services and more tolerant of plant conditions has been completed

  9. Heavy Metal Pollution Potential of Zinc Leach Residues Discarded in çinkur Plant

    OpenAIRE

    ALTUNDOĞAN, H. Soner; ERDEM, Mehmet; ORHAN, Ramazan

    1998-01-01

    In this paper, results of the study on heavy metals solubility behaviour of filter cakes from leaching of clinkerized Waelz oxide and flue dust collected during clinkerization in çinkur plant are given. The release of heavy metals into water was investigated by subjecting the cakes to solubility tests systematically. The effect of contact time, pH, liquid/solid ratio and successive extractions on the releasing of heavy metals (Cd, Pb, Mn and Zn) into water was examined and their conc...

  10. The supply of steam from Candu reactors for heavy water production

    International Nuclear Information System (INIS)

    Robertson, R.F.S.

    1975-09-01

    By 1980, Canada's energy needs for D 2 O production will be 420 MW of electrical energy and 3600 MW of thermal energy (as steam). The nature of the process demands that this energy supply be exceptionally stable. Today, production plants are located at or close to nuclear electricity generating sites where advantage can be taken of the low cost of both the electricity and steam produced by nuclear reactors. Reliability of energy supply is achieved by dividing the load between the multiple units which comprise the sites. The present and proposed means of energy supply to the production sites at the Bruce Heavy Water Plant in Ontario and the La Prade Heavy Water Plant in Quebec are described. (author)

  11. PLANT CONTAMINATION AND PHYTOTOXICITY DUE TO HEAVY METALS FROM SOIL AND WATER

    Directory of Open Access Journals (Sweden)

    Judith Prieto Mendez

    2008-12-01

    Full Text Available High levels of heavy metals, such as: lead, nickel, cadmium and manganese, which are present in soil and wastewater used for agricultural irrigation, are due to the fact that these metals can be accumulated into these systems, of main importance for agriculture. Because of its non-biodegradability features, toxicity effects onto several crops and consequences on their bio-availability, this may result hazardous. This literature survey highlights and remarks relative sensitivity of some plants before heavy metals presence and crops trend to accumulate them, emphasizing aspects related to some soil physicochemical characteristics and heavy metals phyto-toxicity.

  12. Phytoremediation: role of terrestrial plants and aquatic macrophytes in the remediation of radionuclides and heavy metal contaminated soil and water.

    Science.gov (United States)

    Sharma, Sunita; Singh, Bikram; Manchanda, V K

    2015-01-01

    Nuclear power reactors are operating in 31 countries around the world. Along with reactor operations, activities like mining, fuel fabrication, fuel reprocessing and military operations are the major contributors to the nuclear waste. The presence of a large number of fission products along with multiple oxidation state long-lived radionuclides such as neptunium ((237)Np), plutonium ((239)Pu), americium ((241/243)Am) and curium ((245)Cm) make the waste streams a potential radiological threat to the environment. Commonly high concentrations of cesium ((137)Cs) and strontium ((90)Sr) are found in a nuclear waste. These radionuclides are capable enough to produce potential health threat due to their long half-lives and effortless translocation into the human body. Besides the radionuclides, heavy metal contamination is also a serious issue. Heavy metals occur naturally in the earth crust and in low concentration, are also essential for the metabolism of living beings. Bioaccumulation of these heavy metals causes hazardous effects. These pollutants enter the human body directly via contaminated drinking water or through the food chain. This issue has drawn the attention of scientists throughout the world to device eco-friendly treatments to remediate the soil and water resources. Various physical and chemical treatments are being applied to clean the waste, but these techniques are quite expensive, complicated and comprise various side effects. One of the promising techniques, which has been pursued vigorously to overcome these demerits, is phytoremediation. The process is very effective, eco-friendly, easy and affordable. This technique utilizes the plants and its associated microbes to decontaminate the low and moderately contaminated sites efficiently. Many plant species are successfully used for remediation of contaminated soil and water systems. Remediation of these systems turns into a serious problem due to various anthropogenic activities that have

  13. Heavy water at Trail, British Columbia

    International Nuclear Information System (INIS)

    Arsenault, J.E.

    2006-01-01

    Today Canada stands on the threshold of a nuclear renaissance, based on the CANDU reactor family, which depends on heavy water as a moderator and for cooling. Canada has a long history with heavy water, with commercial interests beginning in 1934, a mere two years after its discovery. At one time Canada was the world's largest producer of heavy water. The Second World War stimulated interest in this rather rare substance, such that the worlds largest supply (185 kg) ended up in Canada in 1942 to support nuclear research work at the Montreal Laboratories of the National Research Council. A year later commercial production began at Trail, British Columbia, to support work that later became known as the P-9 project, associated with the Manhattan Project. The Trail plant produced heavy water from 1943 until 1956, when it was shut down. During the war years the project was so secret that Lesslie Thomson, Special Liaison Officer reporting on nuclear matters to C.D. Howe, Minister of Munitions and Supply, was discouraged from visiting Trail operations. Thomson never did visit the Trail facility during the war. In 2005 the remaining large, tall concrete exchange tower was demolished at a cost of about $2.4 million, about the same as it cost to construct the facility about 60 years ago. Thus no physical evidence remains of this historic facility and another important artifact from Canada's nuclear history has disappeared forever. It is planned to place a plaque at the site at some point in the future. (author)

  14. Heavy water at Trail, British Columbia

    Energy Technology Data Exchange (ETDEWEB)

    Arsenault, J.E. [Ontario (Canada)

    2006-09-15

    Today Canada stands on the threshold of a nuclear renaissance, based on the CANDU reactor family, which depends on heavy water as a moderator and for cooling. Canada has a long history with heavy water, with commercial interests beginning in 1934, a mere two years after its discovery. At one time Canada was the world's largest producer of heavy water. The Second World War stimulated interest in this rather rare substance, such that the worlds largest supply (185 kg) ended up in Canada in 1942 to support nuclear research work at the Montreal Laboratories of the National Research Council. A year later commercial production began at Trail, British Columbia, to support work that later became known as the P-9 project, associated with the Manhattan Project. The Trail plant produced heavy water from 1943 until 1956, when it was shut down. During the war years the project was so secret that Lesslie Thomson, Special Liaison Officer reporting on nuclear matters to C.D. Howe, Minister of Munitions and Supply, was discouraged from visiting Trail operations. Thomson never did visit the Trail facility during the war. In 2005 the remaining large, tall concrete exchange tower was demolished at a cost of about $2.4 million, about the same as it cost to construct the facility about 60 years ago. Thus no physical evidence remains of this historic facility and another important artifact from Canada's nuclear history has disappeared forever. It is planned to place a plaque at the site at some point in the future. (author)

  15. Production of heavy water

    Science.gov (United States)

    Spencer, Larry S.; Brown, Sam W.; Phillips, Michael R.

    2017-06-06

    Disclosed are methods and apparatuses for producing heavy water. In one embodiment, a catalyst is treated with high purity air or a mixture of gaseous nitrogen and oxygen with gaseous deuterium all together flowing over the catalyst to produce the heavy water. In an alternate embodiment, the deuterium is combusted to form the heavy water. In an alternate embodiment, gaseous deuterium and gaseous oxygen is flowed into a fuel cell to produce the heavy water. In various embodiments, the deuterium may be produced by a thermal decomposition and distillation process that involves heating solid lithium deuteride to form liquid lithium deuteride and then extracting the gaseous deuterium from the liquid lithium deuteride.

  16. Process control analysis requirement in NH3-H2 exchange bi-thermal Heavy Water Plant (Talcher) (Paper No. 6.8)

    International Nuclear Information System (INIS)

    Pattnaik, S.P.; Mishra, G.C.

    1992-01-01

    Heavy Water Plant, Talcher is based on bithermal NH 3 -H 2 exchange process. Isotopic exchange of deuterium takes place between gaseous hydrogen and liquid ammonia with potassium amide as catalyst. The process control analysis requirement in NH 3 -H 2 exchange dual temperature process is described. (author). 4 refs., 4 figs

  17. Lead uptake of water plants in water stream at Kiteezi landfill site ...

    African Journals Online (AJOL)

    user

    2Chemistry Laboratory, Uganda Industrial Research Institute, P. O. Box 7086, Kampala, Uganda. Received ... contain heavy metals which compromise water quality .... MATERIALS AND METHODS ... discharged out of the waste water treatment plant pipes. ... with deionized water twice and separated into shoots, stems and.

  18. Distribution, Fraction, and Ecological Assessment of Heavy Metals in Sediment-Plant System in Mangrove Forest, South China Sea

    Science.gov (United States)

    Li, Ruili; Chai, Minwei; Qiu, Guo Yu

    2016-01-01

    Overlying water, sediment, rhizosphere sediment and mangrove seedlings in the Futian mangrove forest were analyzed for heavy metals. The results showed that mangrove plant acidified sediment and increased organic matter contents. Except for chromium (Cr), nickel (Ni) and copper (Cu) in Aegiceras corniculatum sediment, heavy metals in all sediments were higher than in overlying water, rhizosphere sediment and mangrove root. Heavy metals in Avicennia marina sediments were higher than other sediments. The lower heavy metal biological concentration factors (BCFs) and translocation factors (TFs) indicated that mangrove plant adopted exclusion strategy. The geo-accumulation index, potential ecological risk index and risk assessment code (RAC) demonstrated that heavy metals have posed a considerable ecological risk, especially for cadmium (Cd). Heavy metals (Cr, Ni, Cu and Cd) mainly existed in the reducible fractions. These findings provide actual heavy metal accumulations in sediment-plant ecosystems in mangrove forest, being important in designing the long-term management and conservation policies for managers of mangrove forest. PMID:26800267

  19. Concentrations of heavy metals and plant nutrients in water, sediments and aquatic macrophytes of anthropogenic lakes (former open cut brown coal mines) differing in stage of acidification

    Energy Technology Data Exchange (ETDEWEB)

    Samecka-Cymerman, A. [Department of Ecology and Nature Protection, Wroclaw University, ul. Kanonia 6/8, 50-328 Wroclaw (Poland); Kempers, A.J. [Department of Biogeology, University of Nijmegen, Toernooiveld, 6525 ED Nijmegen (Netherlands)

    2001-12-17

    Concentration of heavy metals (Al, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr, V and Zn) as well as macronutrients (N, P, K, Ca, Mg, S) were measured in water, bottom sediments and plants from anthropogenic lakes in West Poland. The collected plants were: Phragmites australis, Potamogeton natans, Iris pseudoacorus, Juncus effusus, Drepanocladus aduncus, Juncus bulbosus, Phalaris arundinacea, Carex remota and Calamagrostis epigeios. Two reference lakes were sampled for Nymphaea alba, Phragmites australis, Schoenoplectus lacustris, Typha angustifolia and Polygonum hydropiper. These plants contained elevated levels of Cd, Co, Cr, Cu and Mn, and part of the plants contained in addition elevated levels of Mn, Fe, Pb, Ni and Zn. Analyses of water indicated pollution with sulfates, Cd, Co, Ni, Zn, Pb and Cu, and bottom sediments indicated that some of the examined lakes were polluted with Cd, Co and Cr. Strong positive correlations were found between concentrations of Co in water and in plants and between Zn in sediments and plants, indicating the potential of plants for pollution monitoring for this metal. Heavy metal accumulation seemed to be directly associated with the exclusion of Ca and Mg.

  20. Statistical Analysis Of Heavy Metals Concentration In Watermelon Plants Irrigated By Wastewater

    Science.gov (United States)

    Khanjani, M. J.; Maghsoudi moud, A. A.; Saffari, V. R.; Hashamipor, S. M.; Soltanizadeh, M.

    2008-01-01

    Concentration of heavy metals in vegetables irrigated by urban wastewater is a cause of serious concern due to the potentials health problems of consuming contaminated produce. In this study it is tried to model the concentration of heavy metals (Cd, Cr, Cu, Fe,…) as a function of their concentration in watermelon roots and stems. Our study shows there is a good relationship between them for most of collected data. By measuring the concentration in root and stem of watermelon plant samples before harvesting, the concentration of heavy metal in watermelon's fruit can be estimated by presented mathematical models. This study shows the concentrations of heavy metals in fruits, roots and stems of watermelon plants are very high and in dangerous level when irrigated by municipal waste water.

  1. Technologies for tritium control in fission reactors moderated with heavy water

    International Nuclear Information System (INIS)

    Ramilo, L.B.; Gomez de Soler, S.M.

    1996-01-01

    This study was done within a program one of whose objectives was to analyze the possible strategies and technologies, to be applied to HWR at Argentine nuclear power plants, for tritium control. The high contribution of tritium to the total dose has given rise to the need by the operators and/or designers to carry out developments and improvements to try to optimize tritium control technologies. Within a tritium control program, only that one which includes the heavy water detritiation will allow to reduce the tritium concentrations at optimum levels for safety and cost-effective power plant operation. The technology chosen to be applied should depend not only on the technical feasibility but also on the analysis of economic and juncture factors such as, among others, the quantity of heavy water to be treated. It is the authors' belief that AECL tendency concerning heavy water treatment in its future reactors would be to employ the CECE technology complemented with immobilization on titanium beds, with the 'on-line' detritiation in each nuclear power plant. This would not be of immediate application since our analysis suggests that AECL would assume that the process is under development and needs to be tested. (author). 21 refs

  2. Accounting strategy of tritium inventory in the heavy water detritiation pilot plant from ICIT Rm. Valcea

    International Nuclear Information System (INIS)

    Bidica, N.; Stefanescu, I.; Cristescu, I.; Bornea, A.; Zamfirache, M.; Lazar, A.; Vasut, F.; Pearsica, C.; Stefan, I.; Prisecaru, I.; Sindilar, G.

    2008-01-01

    In this paper we present a methodology for determination of tritium inventory in a tritium removal facility. The method proposed is based on the developing of computing models for accountancy of the mobile tritium inventory in the separation processes, of the stored tritium and of the trapped tritium inventory in the structure of the process system components. The configuration of the detritiation process is a combination of isotope catalytic exchange between water and hydrogen (LPCE) and the cryogenic distillation of hydrogen isotopes (CD). The computing model for tritium inventory in the LPCE process and the CD process will be developed basing on mass transfer coefficients in catalytic isotope exchange reactions and in dual-phase system (liquid-vapour) of hydrogen isotopes distillation process. Accounting of tritium inventory stored in metallic hydride will be based on in-bed calorimetry. Estimation of the trapped tritium inventory can be made by subtraction of the mobile and stored tritium inventories from the global tritium inventory of the plant area. Determinations of the global tritium inventory of the plant area will be made on a regular basis by measuring any tritium quantity entering or leaving the plant area. This methodology is intended to be applied to the Heavy Water Detritiation Pilot Plant from ICIT Rm. Valcea (Romania) and to the Cernavoda Tritium Removal Facility (which will be built in the next 5-7 years). (authors)

  3. Problems connected with the production of heavy water in France; Problemes relatifs a la production d'eau lourde en France

    Energy Technology Data Exchange (ETDEWEB)

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

    1956-07-01

    The decision to study the nuclear energy in France in 1945 has seen the construction of the first natural uranium reactor for research purpose only, Zoe reactor. The utilization of heavy water as moderator was motivated by permitting the economical utilization of natural uranium oxides as fuel and a good handling. The five tons of heavy water required by the Zoe reactor were initially obtained from Norway production. With nuclear development and the construction of the first power reactors for electricity production, the demand in heavy water increased. The heavy water production by French industry became of a great interest. The first production started in the southwest of France using a fertilizers production plant and the electrolytic process used in Norway. The electrolytic process of hydrogen was quickly limited by the limited number of large fertilizers plants in France. Thus, in 1953, French nuclear research concentrated on the distillation of liquid hydrogen and water distillation for the heavy water production. The liquid hydrogen distillation presents a better yield in heavy water extraction than the electrolytic process but it was still depending from large fertilizers production plants. Although the water distillation process is simple, the high purity required for nuclear uses induced a high cost. The advantages and disadvantages of these two processes are discussed as well as others heavy water production processes using concentration process of already enriched water and the prospect of the use of the natural gas from the Lacq deposit. Economical aspect and cost production for each of heavy water production processes will be also discussed. (M.P.)

  4. Heavy Water Quality Management in HANARO

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Ho Chul; Lee, Mun; Kim, Hi Gon; Park, Chan Young; Choi, Ho Young; Hur, Soon Ock; Ahn, Guk Hoon

    2008-12-15

    Heavy water quality management in the reflector tank is a very important element to maintain the good thermal neutron flux and to ensure the performance of reflector cooling system. This report is written to provide a guidance for the future by describing the history of the heavy water quality management during HANARO operation. The heavy water quality in the reflector tank has been managed by measuring the electrical conductivity at the inlet and outlet of the ion exchanger and by measuring pH of the heavy water. In this report, the heavy water quality management activities performed in HANARO from 1996 to 2007 ere described including a basic theory of the heavy water quality management, exchanging history of used resin in the reflector cooling system, measurement data of the pH and the electrical conductivity, and operation history of the reflector cooling system.

  5. Effects of heavy metals on plants and resistance mechanisms. A state-of-the-art report with special reference to literature published in Chinese journals.

    Science.gov (United States)

    Cheng, Shuiping

    2003-01-01

    As one of the consequences of heavy metal pollution in soil, water and air, plants are contaminated by heavy metals in some parts of China. To understand the effects of heavy metals upon plants and the resistance mechanisms, would make it possible to use plants for cleaning and remediating heavy metal-polluted sites. The research results on the effects of heavy metals on plants and resistant mechanisms are compiled from Chinese publications from scientific journals and university journals, mostly published during the last decade. Effects of heavy metals on plants result in growth inhibition, structure damage, a decline of physiological and biochemical activities as well as of the function of plants. The effects and bioavailability of heavy metals depend on many factors, such as environmental conditions, pH, species of element, organic substances of the media and fertilization, plant species. But, there are also studies on plant resistance mechanisms to protect plants against the toxic effects of heavy metals such as combining heavy metals by proteins and expressing of detoxifying enzyme and nucleic acid, these mechanisms are integrated to protect the plants against injury by heavy metals. There are two aspects on the interaction of plants and heavy metals. On one hand, heavy metals show negative effects on plants. On the other hand, plants have their own resistance mechanisms against toxic effects and for detoxifying heavy metal pollution. To study the effects of heavy metals on plants and mechanisms of resistance, one must select crop cultivars and/or plants for removing heavy metals from soil and water. More highly resistant plants can be selected especially for a remediation of the pollution site. The molecular mechanisms of resistance of plants to heavy metals should be studied further to develop the actual resistance of these plants to heavy metals. Understanding the bioavailability of heavy metals is advantageous for plant cultivation and phytoremediation

  6. Influence of temperature and salinity on heavy metal uptake by submersed plants

    Energy Technology Data Exchange (ETDEWEB)

    Fritioff, A. [Department of Botany, Stockholm University, S-106 91 Stockholm (Sweden)]. E-mail: fritioff@botan.su.se; Kautsky, L. [Department of Botany, Stockholm University, S-106 91 Stockholm (Sweden); Greger, M. [Department of Botany, Stockholm University, S-106 91 Stockholm (Sweden)

    2005-01-01

    Submersed plants can be useful in reducing heavy metal concentrations in stormwater, since they can accumulate large amounts of heavy metals in their shoots. To investigate the effects of water temperature and salinity on the metal uptake of two submersed plant species, Elodea canadensis (Michx.) and Potamogeton natans (L.), these plants were grown in the presence of Cu, Zn, Cd, and Pb at 5, 11, and 20 deg. C in combination with salinities of 0, 0.5, and 5%o. The metal concentrations in the plant tissue increased with increasing temperature in both species; the exception was the concentration of Pb in Elodea, which increased with decreasing salinity. Metal concentrations at high temperature or low salinity were up to twice those found at low temperature or high salinity. Plant biomass affected the metal uptake, with low biomass plants having higher metal concentrations than did high biomass plants. - Metal concentrations increase with increasing temperature and decreasing salinity in two aquatic plants.

  7. Influence of temperature and salinity on heavy metal uptake by submersed plants

    International Nuclear Information System (INIS)

    Fritioff, A.; Kautsky, L.; Greger, M.

    2005-01-01

    Submersed plants can be useful in reducing heavy metal concentrations in stormwater, since they can accumulate large amounts of heavy metals in their shoots. To investigate the effects of water temperature and salinity on the metal uptake of two submersed plant species, Elodea canadensis (Michx.) and Potamogeton natans (L.), these plants were grown in the presence of Cu, Zn, Cd, and Pb at 5, 11, and 20 deg. C in combination with salinities of 0, 0.5, and 5%o. The metal concentrations in the plant tissue increased with increasing temperature in both species; the exception was the concentration of Pb in Elodea, which increased with decreasing salinity. Metal concentrations at high temperature or low salinity were up to twice those found at low temperature or high salinity. Plant biomass affected the metal uptake, with low biomass plants having higher metal concentrations than did high biomass plants. - Metal concentrations increase with increasing temperature and decreasing salinity in two aquatic plants

  8. Canadian heavy water production

    International Nuclear Information System (INIS)

    Dahlinger, A.; Lockerby, W.E.; Rae, H.K.

    1977-05-01

    The paper reviews Canadian experience in the production of heavy water, presents a long-term supply projection, relates this projection to the anticipated long-term electrical energy demand, and highlights principal areas for further improvement that form the bulk of our research and development program on heavy water processes

  9. Decontamination of soils polluted with heavy metals using plants as determined by nuclear technique

    International Nuclear Information System (INIS)

    Lotfy, S.M

    2010-01-01

    The objectives of this work were three folds. First, to study the mobility and fate of heavy metals in two polluted sites (Mostorud soil, irrigated with contaminated water for more than 30 years and El-Gabal EL-Asfar soil, subjected to sewage effluent irrigation for more than 50 years) utilizing a modified tessier's sequential extraction procedure to evaluate the effect of total metal concentrations on metal partitioning into different fractions. Second, to evaluate the efficiency of some plant species (sunflower, cotton, penakium, Napier grass, and Squash) to extract heavy metals out of polluted soils. Third, to enhance the phyto-extraction of heavy metals by sunflower plant using some chemical chelators (citric acids, EDTA, and Ammonium nitrate) in order to improve the remediation of pollutants as well as to protect soil quality.It was observed that the distribution of heavy metals in various chemical fractions depends on the total heavy metals content. The distribution of heavy metals forms in the studied soils was in the following decreasing order: residual > Fe-Mn oxides > carbonates > organic > exchangeable > water soluble.Either higher metal accumulation in shoots or enhanced metal accumulation in roots was mainly due to improved phyto-extraction or rhizo-filtration efficiency, respectively. Heavy metals accumulation in shoots and roots of the investigated plant species was as follow: sunflower > cotton > penakium > Napier grass > Squash with a lower order of magnitude. Sunflower showed superiority for heavy metals extraction.Application of chemical chelators (soil amendments) enhanced the phyto-extraction efficiency of heavy metals by sunflower in both Mostorud and El-Gabal El-Asfar soils. Citric acid enhanced metals accumulation in shoots and roots more than EDTA and ammonium nitrate. Citric acid with rate of 20 m mole/kg soil was the best chelators to enhance phyto- extraction of heavy metals by sunflower.

  10. Classification of Plants According to Their Heavy Metal Content ...

    African Journals Online (AJOL)

    Plants like other living organisms respond differently under different environmental conditions. An elevated level of heavy metals is one of the stresses which results into three classes of plants depending on their heavy metal content. The classes of plant species according to their accumulated heavy metals around North ...

  11. Modeling phytoextraction of heavy metals at multiply contaminated soils with hyperaccumulator plants

    OpenAIRE

    Khodaverdiloo, Habib

    2009-01-01

    Soils and waters contaminated with heavy metals pose a major environmental and human health problem that needs an effective and affordable technological solution. Phytoextraction offers a reasonable technology which uses plants to extract the heavy metals from soils. However, the effectiveness of this new method needs to be demonstrated by means of mathematical modeling. The phytoextraction models also are needed to manage the contaminated soils. A thorough literature review indic...

  12. The ecological risk assessment of heavy metals in the Kuihe River basin (Xuzhou section) and the characteristics of plant enrichment

    Science.gov (United States)

    Sun, Ling; Zheng, Lei

    2018-01-01

    In order to investigate Kuihe River basin of heavy metals (As, Cd, Cr, Cu, Mn, Ni, Pb and Zn) pollution, the determination of the Kuihe River water body, the bottom of the river silt, riparian soil plants and heavy metal content of 9 kinds of riparian plants, investigate the pollution situation, so as to screen out the plants that has potential of enrichment and rehabilitation of heavy metal pollution. The results showed that Cd and Mn in the water body exceed bid; The pollution of Zn and Cu in the bottom mud is serious, potential ecological risk of heavy metals is Zn>Cu>Pb>Ni>Cd>As>Cr>Mn Riparian soil affected by sewage and overflow of sediment has significant positive correlation with soil heavy metals, among them, the Zn and Cu are heavy pollution; The selective absorption of heavy metals by 9 kinds of dominant plant leads to its bio concentration factor (BCF) of Cr and Pb on the low side, are all less than 1, from the translocation factor (TF), Setcreasea purpurea and Poa annua showed obvious roots type hoarding. Poa annua and Lycium chinense have a resistance on the absorption of heavy metals, Lythrum salicaria, Photinia serrulata and Broussonetia papyrifera have a unique advantage on enrichment of heavy metals, Broussonetia papyri era on a variety of strong ability of enrichment and transfer of heavy metals suggests that the woody plants in the vast application prospect in the field of rehabilitation technology of heavy metals.

  13. Experience with Inconel-625 in cracker service in heavy water plants (Paper No. 5.6)

    International Nuclear Information System (INIS)

    Ramamurthy, C.B.; Paknikar, K.; Bhushan, Sashi

    1992-01-01

    In ammonia based heavy water plants working on monothermal process enriched ammonia is cracked into its individual constituents for further processing. The cracking of ammonia, which is an endothermic process, takes place in cracker tubes filled with a catalyst which are fired inside a furnace. The design pressure of the tube is 160 kg per sq.cm and the design temperature 765degC. Inconel-625 both wrought and cast type meet the requirements in the temperature range of operation of the cracker and therefore Inconel-625 is the best suited material for the cracker design on the basis of stress rupture strength. The experience with Inconel-625 is described. (author). 4 tabs., 1 fig

  14. Heavy water moderated tubular type nuclear reactor

    International Nuclear Information System (INIS)

    Oohashi, Masahisa.

    1986-01-01

    Purpose: To enable to effectively change the volume of heavy water per unit fuel lattice in heavy water moderated pressure tube type nuclear reactors. Constitution: In a nuclear reactor in which fuels are charged within pressure tubes and coolants are caused to flow between the pressure tubes and the fuels, heavy water tubes for recycling heavy water are disposed to a gas region formed to the outside of the pressure tubes. Then, the pressure tube diameter at the central portion of the reactor core is made smaller than that at the periphery of the reactor core. Further, injection means for gas such as helium is disposed to the upper portion for each of the heavy water tubes so that the level of the heavy water can easily be adjusted by the control for the gas pressure. Furthermore, heavy water reflection tubes are disposed around the reactor core. In this constitution, since the pitch for the pressure tubes can be increased, the construction and the maintenance for the nuclear reactor can be facilitated. Also, since the liquid surface of the heavy water in the heavy water tubes can be varied, nuclear properties is improved and the conversion ratio is improved. (Ikeda, J.)

  15. Heavy water plant

    International Nuclear Information System (INIS)

    Rogers, D.G.

    1978-01-01

    This invention provides an auxiliary contactor column or exchange tower to receive stripped gas and vapour from a stripper. An auxiliary supply of heated feed water is passed in isotope exchanging relation with the gas in the auxiliary contactor to raise the deuterium content of the gas, which then is returned to the main process, at the hot tower or at the feed absorption tower as already described in relation to previous practice. Flow balance between gas and water in the auxiliary contactor is achieved relatively simply by monitoring the deuterium content of the hot water leaving the contactor column, and regulating the supply of hot water, to the contactor column in response thereto. (author)

  16. Operating performance of the prototype heavy water reactor Fugen

    International Nuclear Information System (INIS)

    1984-01-01

    Since the full scale operation was started in March, 1979, the ATR Fugen power station has been verifying the performance and reliability of the machinery and equipment, uranium-plutonium mixed oxide fuel and so on, and obtaining the technical prospect for putting ATRs in practical use by accumulating operation and maintenance techniques, through about five years of operation. In this report, the operational results of the Fugen power station are described. Fugen is a heavy water-moderated, boiling light water-cooled, pressure tube type reactor with 165 MWe output. As of the end of March, 1984, the total generated electric power was about 4.3 billion kWh, and the operation time was about 27,000 hours. The mean capacity ratio reached 58.8%. During the operation period, troubles including plant shutdown occurred eight times, but generally the performance and reliability of the machinery and equipment have been good. 580 fuels including 284 MOX fuels have been charged, but fuel breaking did not occur at all. The consumption of heavy water and the leak of tritium did not cause problem. The management of the core and fuel, the management of maintenance, the quality control of cooling water and heavy water, radiation control and the management of wastes are reported. (Kako, I.)

  17. Quantification of Heavy Metals in Mining Affected Soil and Their Bioaccumulation in Native Plant Species.

    Science.gov (United States)

    Nawab, Javed; Khan, Sardar; Shah, Mohammad Tahir; Khan, Kifayatullah; Huang, Qing; Ali, Roshan

    2015-01-01

    Several anthropogenic and natural sources are considered as the primary sources of toxic metals in the environment. The current study investigates the level of heavy metals contamination in the flora associated with serpentine soil along the Mafic and Ultramafic rocks northern-Pakistan. Soil and wild native plant species were collected from chromites mining affected areas and analyzed for heavy metals (Cr, Ni, Fe, Mn, Co, Cu and Zn) using atomic absorption spectrometer (AAS-PEA-700). The heavy metal concentrations were significantly (p soil as compared to reference soil, however Cr and Ni exceeded maximum allowable limit (250 and 60 mg kg(-1), respectively) set by SEPA for soil. Inter-metal correlations between soil, roots and shoots showed that the sources of contamination of heavy metals were mainly associated with chromites mining. All the plant species accumulated significantly higher concentrations of heavy metals as compared to reference plant. The open dumping of mine wastes can create serious problems (food crops and drinking water contamination with heavy metals) for local community of the study area. The native wild plant species (Nepeta cataria, Impatiens bicolor royle, Tegetis minuta) growing on mining affected sites may be used for soil reclamation contaminated with heavy metals.

  18. Method of controlling power of a heavy water reactor

    International Nuclear Information System (INIS)

    Masuda, Hiroyuki.

    1975-01-01

    Object: To adjust a level of heavy water in a region of reflection body to control power in a heavy water reactor. Structure: The interior of a core tank filled with heavy water is divided by a partition into a core heavy water region and a reflection body region formed by surrounding the core heavy water region, and a level of heavy water within the reflection body region is adjusted to control power. Preferably, it is desirable to communicate the core heavy water region with the reflection body heavy water region at their lower portion, and gas pressure applied to an upper portion within at least one of said regions is adjusted to adjust the level of heavy water within the reflection body heavy water region. Thereby, the heavy water within the reflection body heavy water region may be introduced into the core region, thus requiring no tank which stores heavy water within the reflection body region. (Kamimura, M.)

  19. Advanced technology heavy water monitors offering reduced implementation costs

    International Nuclear Information System (INIS)

    Kalechstein, W.; Hippola, K.B.

    1984-10-01

    The development of second generation heavy water monitors for use at CANDU power stations and heavy water plants has been completed and the instruments brought to the stage of commercial availability. Applications of advanced technology and reduced utilization of custom manufactured components have together resulted in instruments that are less expensive to produce than the original monitors and do not require costly station services. The design has been tested on two prototypes and fully documented, including the inspection and test procedures required for manufacture to the CSA Z299.3 quality verfication program standard. Production of the new monitors by a commercial vendor (Barringer Research Ltd.) has begun and the first instrument is scheduled for delivery to CRNL's NRU reactor in late 1984

  20. Phytoremediation of heavy metal-contaminated water and sediment by eleocharis acicularis

    Energy Technology Data Exchange (ETDEWEB)

    Sakakibara, Masayuki; Ha, Nguyen Thi Hoang [Graduate School of Science and Engineering, Ehime University, Matsuyama (Japan); Ohmori, Yuko [Graduate School of Science and Engineering, Ehime University, Matsuyama (Japan); Taisei Kiso Sekkei Co., Ltd., Tokyo (Japan); Sano, Sakae [Faculty of Education, Ehime University, Matsuyama (Japan); Sera, Koichiro [Cyclotron Center, Iwate Medical University, Takizawa-mura (Japan)

    2011-08-15

    Phytoremediation is an environmental remediation technique that takes advantage of plant physiology and metabolism. The unique property of heavy metal hyperaccumulation by the macrophyte Eleocharis acicularis is of great significance in the phytoremediation of water and sediments contaminated by heavy metals at mine sites. In this study, a field cultivation experiment was performed to examine the applicability of E. acicularis to the remediation of water contaminated by heavy metals. The highest concentrations of heavy metals in the shoots of E. acicularis were 20 200 mg Cu/kg, 14 200 mg Zn/kg, 1740 mg As/kg, 894 mg Pb/kg, and 239 mg Cd/kg. The concentrations of Cu, Zn, As, Cd, and Pb in the shoots correlate with their concentrations in the soil in a log-linear fashion. The bioconcentration factor for these elements decreases log-linearly with increasing concentration in the soil. The results indicate the ability of E. acicularis to hyperaccumulate Cu, Zn, As, and Cd under natural conditions, making it a good candidate species for the phytoremediation of water contaminated by heavy metals. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Advanced electrolytic cascade process for tritium recovery from irradiated heavy water moderator (Preprint No. PD-15)

    International Nuclear Information System (INIS)

    Ragunathan, P.; Mitra, S.K.; Jain, D.K.; Nayar, M.G.; Ramani, M.P.S.

    1989-04-01

    The paper briefly describes a design study of an electrolytic cascade process plant for enrichment and recovery of tritium from irradiated heavy water moderators from Rajasthan Atomic Power Station Reactors. In direct multistage electrolysis process, tritiated heavy water from the reactor units is fed to the electrolytic cell modules arranged in the form of a cascade where it is enriched and decomposed into O 2 gas stream and D 2 /DT gas stream. The direct electrolysis of tritiated heavy water allows tritium to be concentrated in the aqueous phase. Several stages are used to achieve the necessary enrichment. The cascade plant incorporates the advanced electrolyser technology developed in Bhabha Atomic Research Centre (Bombay) using porous nickel electrodes, capable o f high current density operation at reduced energy consumption for electrolysis. (author). 3 tabs

  2. Water chemistry features of advanced heavy water reactor

    International Nuclear Information System (INIS)

    Sriram, Jayasree; Vijayan, K.; Kain, Vivekanad; Velmurugan, S.

    2015-01-01

    Advanced Heavy Water Reactor (AHWR) being designed in India proposes to use Plutonium and Thorium as fuel. The objective is to extract energy from the uranium-233 formed from Thorium. It is a heavy water moderated and light water cooled tube type boiling water reactor. It is a heavy water moderated and light water cooled tube type boiling water reactor. It is a natural circulation reactor. Thus, it has got several advanced passive safety features built into the system. The various water coolant systems are listed below. i) Main Heat transport System ii) Feed water system iii) Condenser cooling system iv) Process water system and safety systems. As it is a tube type reactor, the radiolysis control differs from the normal boiling water reactor. The coolant enters the bottom of the coolant channel, boiling takes place and then the entire steam water mixture exits the core through the long tail pipes and reaches the moisture separator. Thus, there is a need to devise methods to protect the tail pipes from oxidizing water chemistry condition. Similarly, the moderator heavy water coolant chemistry differs from that of moderator system chemistry of PHWR. The reactivity worth per ppm of gadolinium and boron are low in comparison to PHWR. As a result, much higher concentration of neutron poison has to be added for planned shutdown, start up and for actuating SDS-2. The addition of higher concentration of neutron poison result in higher radiolytic production of deuterium and oxygen. Their recombination back to heavy water has to take into account the higher production of these gases. This paper also discusses the chemistry features of safety systems of AHWR. In addition, the presentation will cover the chemistry monitoring methodology to be implemented in AHWR. (author)

  3. Study of the heavy water regeneration processes

    International Nuclear Information System (INIS)

    Cavcic, E.

    1965-11-01

    Experience derived from heavy water reactor operation showed degradation and dilution of heavy water to be inevitable and depends on the type of reactor. Dilution of heavy water during operation of the RA and the RB reactors is shown in this report. Principles and procedures of heavy water regeneration by electrolysis, fractional distillation, cleaning, prevention of tritium contamination are described as well as separation columns

  4. A study of the tritium behavior in coolant and moderator system of heavy water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S. P.; Song, S. S.; Chae, K. S. and others [Chosun Univ., Gwangju (Korea, Republic of)

    1993-12-15

    The objectives of this report is to present a regulatory policy on the environmental impact and personnel exposure by understanding the generation, accumulation, environmental release and management of tritium in heavy water reactors. By estimating the tritium concentration at Wolsong nuclear plant site by estimating and forecasting the generation and accumulation of tritium in coolant and moderator systems at Wolsong unit 1, we will study the management and release of tritium at Wolsong units 3 and 4 which are ready for construction. The major activities of this study are as follows : tritium generation and accumulation in heavy water reactor, a quantitative assessment of the accumulation and release of tritium at Wolsong nuclear plant site, heavy water management at Wolsong nuclear plants. The tritium concentration and accumulation trends in the systems at Wolsong unit 1 was estimated. A quantitative assessment of the tritium accumulation and release for Wolsong 2, 3 and 4 based on data from Wolsong 1 was performed. The tritium removal schemes and its long-term management plan were made.

  5. Heavy Water - Industrial Separation Processes

    International Nuclear Information System (INIS)

    Peculea, M.

    1984-01-01

    This monograph devoted to the heavy water production mainly presents the Romanian experience in the field which started in early sixties from the laboratory scale production and reached now the level of large scale industrial production at ROMAG-Drobeta, Romania. The book is structured in eleven chapters entitled: Overview, The main physical properties, Sources, Uses, Separation factor and equilibrium constant, Mathematical modelling of the separation process, Thermodynamical considerations on the isotope separation, Selection criteria for heavy water separation processes, Industrial installations for heavy water production, Prospects, Acknowledgements. 200 Figs., 90 Tabs., 135 Refs

  6. H2S absorption and desorption system for a heavy water production plant (Gird ler-Sulphide method)

    International Nuclear Information System (INIS)

    Diaz, F.; Duran, O.

    1987-01-01

    A computational design for the principal equipment involved in the absorption and desorption sections of a heavy water production plant (Girdler-sulphide method) is described. the programs were developed in FORTRAN. A detailled description of transport equations for the desorption tower, which are applicable for the absorption one is included. The optimization criteria used for the equipment design were mainly economic; the results were obtained under the optimal conditions for the towers. The programs may be used in the long term, for the simulation of the absorption and desorption sections together with the isotopic exchange sectionts (author)

  7. Heavy Metal Stress, Signaling, and Tolerance Due to Plant-Associated Microbes: An Overview

    Science.gov (United States)

    Tiwari, Shalini; Lata, Charu

    2018-01-01

    Several anthropogenic activities including mining, modern agricultural practices, and industrialization have long-term detrimental effect on our environment. All these factors lead to increase in heavy metal concentration in soil, water, and air. Soil contamination with heavy metals cause several environmental problems and imparts toxic effect on plant as well as animals. In response to these adverse conditions, plants evolve complex molecular and physiological mechanisms for better adaptability, tolerance, and survival. Nowadays conventional breeding and transgenic technology are being used for development of metal stress resistant varieties which, however, are time consuming and labor intensive. Interestingly the use of microbes as an alternate technology for improving metal tolerance of plants is gaining momentum recently. The use of these beneficial microorganisms is considered as one of the most promising methods for safe crop-management practices. Interaction of plants with soil microorganisms can play a vital role in acclimatizing plants to metalliferous environments, and can thus be explored to improve microbe-assisted metal tolerance. Plant-associated microbes decrease metal accumulation in plant tissues and also help to reduce metal bioavailability in soil through various mechanisms. Nowadays, a novel phytobacterial strategy, i.e., genetically transformed bacteria has been used to increase remediation of heavy metals and stress tolerance in plants. This review takes into account our current state of knowledge of the harmful effects of heavy metal stress, the signaling responses to metal stress, and the role of plant-associated microbes in metal stress tolerance. The review also highlights the challenges and opportunities in this continued area of research on plant–microbe–metal interaction. PMID:29681916

  8. Study of the light and heavy water leaks in nuclear reactors and development of techniques for their detection, location and estimation

    International Nuclear Information System (INIS)

    Bashiruddin Mahmood, S.

    1979-01-01

    In heavy water type nuclear reactors the detection and control of heavy water and light water escapes from different systems is of vital importance in the successful and economic operation of these type of plants. The high cost of heavy water makes it imperative to minimise all such escapes, in order to reduce the loss as well as the upgrading cost of downgraded collection recovered from the reactor building. Original methods and devices have been developed at the Karachi Nuclear Power Plant which successfully solve this problem. This report describes the constructional and operational features of these devices

  9. HAZOP-study on heavy water research reactor primary cooling system

    International Nuclear Information System (INIS)

    Hashemi-Tilehnoee, M.; Pazirandeh, A.; Tashakor, S.

    2010-01-01

    By knowledge-based Hazard and Operability (HAZOP) technique, equipment malfunction and deficiencies in the primary cooling system of the generic heavy water research reactor are studied. This technique is used to identify the representative accident scenarios. The related Process Flow Drawing (PFD) is prepared as our study database for this plant. Since this facility is in the design stage, applying the results of HAZOP-study to PFD improves the safety of the plant.

  10. The solubility of iron sulfides and their role in mass transport in Girdler-Sulfide heavy water plants

    International Nuclear Information System (INIS)

    Tewari, P.H.; Wallace, G.; Campbell, A.B.

    1978-04-01

    The solubilities of several iron sulfides, mackinawite FeSsub((1-x)), troilite FeS, pyrrhotite Fesub((1-x))S (monoclinic and hexagonal), and pyrite FeS 2 have been determined in aqueous H 2 S solution at 0.1 MPa and 1.8 MPa H 2 S pressures between 25 deg and 125 deg C. The dependence of solubility on the pH of the medium has also been studied. It is concluded that since mackinawite is the most soluble of the iron sulfides, and has the highest dissolution rate and the steepest decline in solubility with temperature, its prolonged formation during plant operation should be avoided to minimize iron transport from lower to higher temperature areas in Girdler-Sulfide (G.S.) heavy water plants. This can be achieved by a preconditioning of carbon steel surfaces to convert mackinawite to pyrrhotite and pyrite

  11. Plant response to heavy metals and organic pollutants in cell culture and at whole plant level

    Energy Technology Data Exchange (ETDEWEB)

    Golan-Goldhirsh, A.; Barazani, O. [Ben-Gurion Univ. of The Negev, The Jacob Blaustein Inst. for Desert Research, Albert Katz Dept. of Dryland Biotechnologies, Desert Plant Biotechnology Lab., Sede Boqer Campus (Israel); Nepovim, A.; Soudek, P.; Vanek, T. [Inst. of Organic Chemistry and Biochemistry (Czech Republic); Smrcek, S.; Dufkova, L.; Krenkova, S. [Faculty of Natural Sciences, Charles Univ. (Czech Republic); Yrjala, K. [Univ. of Helsinki, Dept. of Biosciences, Div. of General Microbiology, Helsinki (Finland); Schroeder, P. [Inst. for Soil Ecology, GSF National Research Center for Environment and Health, Neuherberg, Oberschleissheim (Germany)

    2004-07-01

    Background. Increasing awareness in the last decade concerning environmental quality had prompted research into 'green solutions' for soil and water remediation, progressing from laboratory in vitro experiments to pot and field trials. In vitro cell culture experiments provide a convenient system to study basic biological processes, by which biochemical pathways, enzymatic activity and metabolites can be specifically studied. However, it is difficult to relate cell cultures, calli or even hydroponic experiments to the whole plant response to pollutant stress. In the field, plants are exposed to additional a-biotic and biotic factors, which complicate further plant response. Hence, we often see that in vitro selected species perform poorly under soil and field conditions. Soil physical and chemical properties, plant-mycorrhizal association and soil-microbial activity affect the process of contaminant degradation by plants and/or microorganisms, pointing to the importance of pot and field experiments. Objective. This paper is a joint effort of a group of scientists in COST action 837. It represents experimental work and an overview on plant response to environmental stress from in vitro tissue culture to whole plant experiments in soil. Results. Results obtained from in vitro plant tissue cultures and whole plant hydroponic experiments indicate the phytoremediation potential of different plant species and the biochemical mechanisms involved in plant tolerance. In pot experiments, several selected desert plant species, which accumulated heavy metal in hydroponic systems, succeeded in accumulating the heavy metal in soil conditions as well. Conclusions and recommendations. In vitro plant tissue cultures provide a useful experimental system for the study of the mechanisms involved in the detoxification of organic and heavy metal pollutants. However, whole plant experimental systems, as well as hydroponics followed by pot and field trials, are essential when

  12. Heavy Metal Stress, Signaling, and Tolerance Due to Plant-Associated Microbes: An Overview

    Directory of Open Access Journals (Sweden)

    Shalini Tiwari

    2018-04-01

    Full Text Available Several anthropogenic activities including mining, modern agricultural practices, and industrialization have long-term detrimental effect on our environment. All these factors lead to increase in heavy metal concentration in soil, water, and air. Soil contamination with heavy metals cause several environmental problems and imparts toxic effect on plant as well as animals. In response to these adverse conditions, plants evolve complex molecular and physiological mechanisms for better adaptability, tolerance, and survival. Nowadays conventional breeding and transgenic technology are being used for development of metal stress resistant varieties which, however, are time consuming and labor intensive. Interestingly the use of microbes as an alternate technology for improving metal tolerance of plants is gaining momentum recently. The use of these beneficial microorganisms is considered as one of the most promising methods for safe crop-management practices. Interaction of plants with soil microorganisms can play a vital role in acclimatizing plants to metalliferous environments, and can thus be explored to improve microbe-assisted metal tolerance. Plant-associated microbes decrease metal accumulation in plant tissues and also help to reduce metal bioavailability in soil through various mechanisms. Nowadays, a novel phytobacterial strategy, i.e., genetically transformed bacteria has been used to increase remediation of heavy metals and stress tolerance in plants. This review takes into account our current state of knowledge of the harmful effects of heavy metal stress, the signaling responses to metal stress, and the role of plant-associated microbes in metal stress tolerance. The review also highlights the challenges and opportunities in this continued area of research on plant–microbe–metal interaction.

  13. Various analytical techniques used for the measurement of isotopic purity of heavy water at Madras Atomic Power Station

    International Nuclear Information System (INIS)

    Satyanarayanan, V.; Umapathy, P.; Bhaskaran, R.; Nagarajan, J.; Pradeep, Jeena; Ayyar, S.R.

    2008-01-01

    The paper deals with the various techniques used for the measurement of isotopic purity of heavy water samples received from different sources viz. reactor systems, heavy water upgrading plant and fresh consignment from heavy water production plants. Heavy water is used in PHWRs as moderator and primary coolant. Isotopic Purity is an important parameter to be monitored/analysed regularly for both the systems. There is a minimum isotopic purity level to be maintained in the moderator system due to neutron economy/fuel burnup and in the case of coolant system the measurement is of paramount importance due to its safety considerations. The selection of the method of analysis depends on the isotopic range. The techniques used to measure the isotopic purity of heavy water are a) Infrared Spectrophotometry b) Refractometry c) Densitometry. Infrared spectrometer uses the property of molecular absorption of IR radiation by HOD species and the absorbance is the measure of isotopic purity. This technique is generally used for measuring high isotopic (80-99.98%) and low isotopic samples. Refractometer uses the property of refractive index of heavy water. The difference in refractive indices of light water and heavy water is 0.0048. A 1 % change in D 2 O concentration would thus equal to 0.000048 refractive index units. This method is used for determining the approximate isotopic value of a sample. Density meter uses the property of difference in densities of light and heavy water. The difference in density of 99.999% D 2 O and light water is 0.107540 which covers the whole range of interest. The experience gained with these techniques in the measurements of isotopic purity of various samples are presented in this paper. (author)

  14. Possibilities of tritium removal from waste waters of pressurized water reactors and fuel reprocessing plants

    International Nuclear Information System (INIS)

    Ribnikar, S.V.; Pupezin, J.D.

    1975-01-01

    Starting from parameters known for heavy water production processes, a parallel was made with separation of tritium from water. The quantity in common is the total cascade flow. The most efficient processes appear to be hydrogen sulfide, water exchange, hydrogen- and water distillation. Prospects of application of new processes are discussed briefly. Problems concerning detritiation of pressurized water reactors and large fuel reprocessing plants are analyzed. Detritiation of the former should not present problems. With the latter, economical detritiation can be achieved only after some plant flow patterns are changed. (U.S.)

  15. Heavy metals in a degraded soil treated with sludge from water treatment plant

    Directory of Open Access Journals (Sweden)

    Teixeira Sandra Tereza

    2005-01-01

    Full Text Available The application of water treatment sludge (WTS to degraded soil is an alternative for both residue disposal and degraded soil reclaim. This study evaluated effects of the application of water treatment sludge to a Typic Hapludox soil degraded by tin mining in the National Forest of Jamari, State of Rondonia, Brazil, on the content of heavy metals. A completely randomized experimental design with five treatments was used: control (n = 4; chemical control, which received only liming (n = 4; and rates D100, D150 and D200, which corresponded to 100, 150 and 200 mg of N-sludge kg-1 soil (n = 20, respectively. Thirty days after liming, period in which soil moisture was kept at 70% of the retention capacity, soil samples were taken and analyzed for total and extractable Fe, Cu, Mn, Zn, Cd, Pb, Ni, and Cr. The application of WTS increased heavy-metal contents in the degraded soil. Although heavy metals were below their respective critical limits, sludge application onto degraded areas may cause hazardous environmental impact and thus must be monitored.

  16. A methodology for determination of tritium inventory to the heavy water detritiation pilot plant from ICIT Rm. Valcea

    International Nuclear Information System (INIS)

    Bidica, N.; Stefanescu, I.; Bornea, A.; Zamfirache, M.; Lazar, A.; Vasut, F.; Pearsica, C.; Stefan, I.; Cristescu, I.; Prisecaru, I.; Sindilar, G.

    2007-01-01

    Full text: In this paper we present a methodology for determination of tritium inventory in a tritium removal facility. The method proposed is based on the developing of computing models for accountancy of the mobile tritium inventory in the separation processes of the stored tritium and of the trapped tritium inventory in the structure of the process system components. The configuration of the detritiation process is a combination of isotope catalytic exchange between water and hydrogen (LPCE) and the cryogenic distillation of hydrogen isotopes (CD). The computing model for tritium inventory in the LPCE process and the CD process will be developed based on mass transfer coefficients in catalytic isotope exchange reactions and in dual-phase system (liquid-vapour) of hydrogen isotopes distillation process. Accounting of tritium inventory stored in metallic hydride will be based on in-bed calorimetry. Estimation of the trapped tritium inventory can be made by subtraction of the mobile and stored tritium inventories from the global tritium inventory of the plant area. Determinations of the global tritium inventory of the plant area will be made on a regular basis by measuring any tritium amount entering or leaving the plant area. This methodology is intended to be applied to the Heavy Water Detritiation Pilot Plant from ICIT Rm. Valcea (Romania) and at the Cernavoda Tritium Removal Facility (which will be built in the next 5-7 years). (authors)

  17. The security management of spent filter cartridge in Qinshan phase 3 (heavy water reactor) nuclear power plant

    International Nuclear Information System (INIS)

    Xue Dahai

    2005-01-01

    Qinshan phase 3 nuclear power plant is the first CANDU plant that China fetched in from Canada, and both two units operate under well condition up to now. The radioactive wastes produced during the unit operation mainly include technical waste, spent resin, and spent filter cartridge. The spent filter cartridge is one important part both in the volume and radioactivity of the radioactive waste, and it is the important content of radioactive waste management. Different from PWR, part of high radioactive spent filter in CANDU unit comes from heavy water system such as moderator system. It has to be dried through blowing before replaced from the system. But this working procedure result the filtrate dreg become flexible, and it can bring on the risk of internal or external exposure. It is very important to pay high attention to control the contamination spread during spent filter inside transfer. (authors)

  18. The importance of heavy water in nuclear technology

    International Nuclear Information System (INIS)

    Gharib, A.G.

    2004-01-01

    Due to similarities of chemical and almost physical properties in H 2 O and D 2 O but differences in nuclear and particle peculiarities provide valuable application for D 2 O. To sustain a controlled chain reaction, the energy of neutrons produced by fission must be reduced through collisions with other nuclei, a process called moderation. A good moderator has a mass close to that of the neutron to maximize energy loss per collision and a very small neutron capture cross section to minimize unwanted nuclear reactions. Deuterium is far the best moderator, more than 80 times better than hydrogen and 30 times better than 12 C ir 18 O. Heavy water is almost as good as deuterium and has the distinct advantage of being a nonflammable liquid. Heavy water is also an excellent neutron reflector, and thus decreases the number of neutrons that escape the reactor core without participating in fission reactions. For this reason a feasibility study and subsequently a technical survey was carried out on engineering of a pilot scale plant. As the result of this studies, the know-how of heavy water production on basis of selected method including dual temperature isotopic exchange and distillation techniques developed. Subsequently the primary and almost detail engineering documents prepared on best knowledge of our own engineers without external contribution

  19. The performance of alloy 625 in the high temperature application of Heavy Water Plants

    International Nuclear Information System (INIS)

    Mitra, J.; Dey, G.K.; Sundararaman, M.; Dubey, J.S.; De, P.K.; Kumar, Niraj

    2006-01-01

    Wrought and centrifugally cast alloy 625 tubes are used in the cracker units of ammonia based Heavy Water Plants (HWP). During the service of about 100,000 h, the ammonia cracker tubes, predictably, have been exposed to temperatures below 600degC to above 765degC and have undergone several hundreds of start-shutdown cycles, producing several ordered phases in the alloy. To understand the effect of the ordered phases on the structure properties, Alloy 625 samples were aged at 540degC, 700degC and 850degC temperatures, for duration up to 1200 h. Results were compared with that of cast and wrought Alloy 625 samples, which aged during the service of 100,000 h and that failed during the service after about 24,000 h along with that of aged samples, which were resolutionised at 1170degC for 2h. (author)

  20. Detection of heavy metals in water in Negeri Sembilan, Malaysia: From source to consumption

    Science.gov (United States)

    Khalaf, Baydaa; Abdullah, Md. Pauzi; Tahrim, Nurfaizah Abu

    2018-04-01

    Drinking water should be free from harmful levels of impurities, such as heavy metals. The aim of this study is to investigate the heavy metals concentrations in a water reticulation system of Negeri Sembilan. 25 stations were selected along Sungai Linggi (upstream of intake point) and through there reticulation system of Sungai Linggi Water Treatment Plant encompassing raw water through to the last point of use. Sampling activities were carried out in June and July 2016. The samples taken were analysed for heavymetals using an Inductively Coupled Plasma - Optical Emission Spectrometer (ICP-OES). In addition other water quality parameters were measured in situ (pH, water temperature, conductivity and dissolved oxygen) and analysed in the laboratory (BOD, COD, TSS, NH3-N, TOC and residual chlorine). The results showed a high level of Ca in the distribution system, while in the treatment plant it was normal, as well as Fe is decreased. Meanwhile Mn is decreased after treatment processes. The concentrations of DO and temperature in the tap water exceeded the standard concentrations.

  1. Divergent biology of facultative heavy metal plants.

    Science.gov (United States)

    Bothe, Hermann; Słomka, Aneta

    2017-12-01

    Among heavy metal plants (the metallophytes), facultative species can live both in soils contaminated by an excess of heavy metals and in non-affected sites. In contrast, obligate metallophytes are restricted to polluted areas. Metallophytes offer a fascinating biology, due to the fact that species have developed different strategies to cope with the adverse conditions of heavy metal soils. The literature distinguishes between hyperaccumulating, accumulating, tolerant and excluding metallophytes, but the borderline between these categories is blurred. Due to the fact that heavy metal soils are dry, nutrient limited and are not uniform but have a patchy distribution in many instances, drought-tolerant or low nutrient demanding species are often regarded as metallophytes in the literature. In only a few cases, the concentrations of heavy metals in soils are so toxic that only a few specifically adapted plants, the genuine metallophytes, can cope with these adverse soil conditions. Current molecular biological studies focus on the genetically amenable and hyperaccumulating Arabidopsis halleri and Noccaea (Thlaspi) caerulescens of the Brassicaceae. Armeria maritima ssp. halleri utilizes glands for the excretion of heavy metals and is, therefore, a heavy metal excluder. The two endemic zinc violets of Western Europe, Viola lutea ssp. calaminaria of the Aachen-Liège area and Viola lutea ssp. westfalica of the Pb-Cu-ditch of Blankenrode, Eastern Westphalia, as well as Viola tricolor ecotypes of Eastern Europe, keep their cells free of excess heavy metals by arbuscular mycorrhizal fungi which bind heavy metals. The Caryophyllaceae, Silene vulgaris f. humilis and Minuartia verna, apparently discard leaves when overloaded with heavy metals. All Central European metallophytes have close relatives that grow in areas outside of heavy metal soils, mainly in the Alps, and have, therefore, been considered as relicts of the glacial epoch in the past. However, the current

  2. Technical status study of heavy water enrichment

    International Nuclear Information System (INIS)

    Sukarsono; Imam Dahroni; Didik Herhady

    2007-01-01

    Technical status study of heavy water enrichment in Indonesia and also in the world has been done. Heavy water enrichment processes have been investigated were water distillation, hydrogen distillation, laser enrichment, electrolysis and isotop exchange. For the isotop exchange, the chemical pair can be used were water-hydrogen sulphite, ammonium-hydrogen, aminomethane-hydrogen, and water-hydrogen. For the isotope exchange, there was carried out by mono thermal or bi thermal. The highest producer of heavy water is Canada, and the other producer is USA, Norwegian and India. The processes be used in the world are isotope exchange Girdler Sulphide (GS), distillation and electrolysis. Research of heavy water carried out in Batan Yogyakarta, has a purpose to know the characteristic of heavy water purification. Several apparatus which has erected were 3 distillation column: Pyrex glass of 2 m tall, stainless steel column of 3 m tall and steel of 6 m tall. Electrolysis apparatus is 50 cell electrolysis and an isotope exchange unit which has catalyst: Ni- Cr 2 O 3 and Pt-Carbon. These apparatus were not ready to operate. (author)

  3. The heavy water accountancy for research reactors in JAERI

    International Nuclear Information System (INIS)

    Yoshijima, Tetsuo; Tanaka, Sumitoshi; Nemoto, Denjirou

    1998-11-01

    The three research reactors have been operated by the Department of Research Reactor and used about 41 tons heavy water as coolant, moderator and reflector of research reactors. The JRR-2 is a tank type research reactor of 10MW in thermal power and its is used as moderator, coolant and reflector about 16 tons heavy water. The JRR-3M is a light water cooled and moderated pool type research reactor with a thermal power of 20MW and its is used as reflector about 7.3 tons heavy water. In the JRR-4, which is a light water cooled swimming pool type research reactor with the maximum thermal power of 3.5MW, about 1 ton heavy water is used to supply fully thermalized neutrons with a neutron beam experiment of facility. The heavy water was imported from U.S.A., CANADA and Norway. Parts of heavy water is internationally controlled materials, therefore management of heavy water is necessary for materials accountancy. This report described the change of heavy water inventories in each research reactors, law and regulations for accounting of heavy water in JAERI. (author)

  4. General description of advanced heavy water reactor

    International Nuclear Information System (INIS)

    Kakodkar, A.; Sinha, R.K.; Dhawan, M.L.

    1999-01-01

    Advanced Heavy Water Reactor is a boiling light water cooled, heavy water moderated and vertical pressure tube type reactor with its design optimised for utilisation of thorium for power generation. The core consists of (Th-U 233 )O 2 and (Th-Pu)O 2 fuel with a discharge burn up of 20,000 MWd/Te. This reactor incorporates several features to simplify the design, which eliminate certain systems and components. AHWR design is also optimised for easy replaceability of coolant channels, facilitation of in-service inspection and maintenance and ease of erection. The AHWR design also incorporates several passive systems for performing safety-related functions in the event of an accident. In case of LOCA, emergency coolant is injected through 4 accumulators of 260 m 3 capacity directly into the core. Gravity driven water pool of capacity 6000 m 3 serves to cool the core for 3 days without operator's intervention. Core submergence, passive containment isolation and passive containment cooling are the added features in AHWR. The paper describes the various process systems, core and fuel design, primary components and safety concepts of AHWR. Plant layout and technical data are also presented. The conceptual design of the reactor has been completed, and the detailed design and development is scheduled for completion in the year 2002. (author)

  5. Combined biological treatment of sinter plant waste water, blast furnace gas scrubber water polluted groundwater and coke plant effluent

    Energy Technology Data Exchange (ETDEWEB)

    Antoine van Hoorn [Corus Staal, IJmuiden (Netherlands)

    2006-07-01

    Waste water from the Corus coke plant in IJmuiden had been handled by the activated sludge process since start-up in 1972 but in the eighties it was clear that although this removed most phenols, the rest of the COD and thiocyanate must also be removed before discharge. The paper describes the original water treatment process and the higher pressure gas scrubber system for removal of SO{sub 2}, heavy metals and other harmful components. It goes on to describe development of a combined biological treatment system, the heart of which is the so-called Bio 2000. The performance of this new plant is discussed. COD concentrations are very constant but Total Kjeldahl Nitrogen (TKN) concentrations fluctuate. COD, TKN and heavy metals are in compliance but cyanide and suspended solids are not always so. A method of overcoming this is being sought. This paper was presented at a COMA meeting in March 2005 held in Scunthorpe, UK. 10 figs., 2 tabs.

  6. Licensing assessment of the Candu Pressurized Heavy Water Reactor. Preliminary safety information document. Volume II

    International Nuclear Information System (INIS)

    1977-06-01

    ERDA has requested United Engineers and Constructors (UE and C) to evaluate the design of the Canadian natural uranium fueled, heavy water moderated (CANDU) nuclear reactor power plant to assess its conformance with the licensing criteria and guidelines of the U.S. Nuclear Regulatory Commission (USNRC) for light water reactors. This assessment was used to identify cost significant items of nonconformance and to provide a basis for developing a detailed cost estimate for a 1140 MWe, 3-loop Pressurized Heavy Water Reactor (PHWR) located at the Middletown, USA Site

  7. Ecological investigations on plant associations in differently disturbed heavy-metal contaminated soils of Great Britain

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, W

    1968-01-01

    In different areas of Great Britain comparing ecological studies have been made on disturbed and undisturbed heavy metal contaminated soils. In Grizedale (Pennine), sampling of an undisturbed transect having high levels of major nutrients showed marked differentiation within a small area, only related to the plant available levels of zinc, copper, and lead. However, studies on disturbed heavy metal soils and spoil-heaps revealed a low water capacity and a low supply of major nutrients, particularly of N and P. These suggest that here both the enrichment of heavy metals and the considerable decrease of other nutrients are important in determining the heavy metal vegetation, and in maintaining it against other species. The quantity of zinc in plants is not related to the total or plant-available amount of zinc in soil, but confirmed physiological experiments on the influence of phosphorus and different zinc compounds (complexed or inorganic) on the uptake and distribution of zinc in Thlaspi alpestre and Minnartia rerum. Also an antagonism between lead and copper was revealed. 24 references.

  8. Irrigation water quality influences heavy metal uptake by willows in biosolids.

    Science.gov (United States)

    Laidlaw, W Scott; Baker, Alan J M; Gregory, David; Arndt, Stefan K

    2015-05-15

    Phytoextraction is an effective method to remediate heavy metal contaminated landscapes but is often applied for single metal contaminants. Plants used for phytoextraction may not always be able to grow in drier environments without irrigation. This study investigated if willows (Salix x reichardtii A. Kerner) can be used for phytoextraction of multiple metals in biosolids, an end-product of the wastewater treatment process, and if irrigation with reclaimed and freshwater influences the extraction process. A plantation of willows was established directly onto a tilled stockpile of metal-contaminated biosolids and irrigated with slightly saline reclaimed water (EC ∼2 dS/cm) at a wastewater processing plant in Victoria, Australia. Biomass was harvested annually and analysed for heavy metal content. Phytoextraction of cadmium, copper, nickel and zinc was benchmarked against freshwater irrigated willows. The minimum irrigation rate of 700 mm per growing season was sufficient for willows to grow and extract metals. Increasing irrigation rates produced no differences in total biomass and also no differences in the extraction of heavy metals. The reclaimed water reduced both the salinity and the acidity of the biosolids significantly within the first 12 months after irrigation commenced and after three seasons the salinity of the biosolids had dropped to metal extraction. Reclaimed water irrigation reduced the biosolid pH and this was associated with reductions of the extraction of Ni and Zn, it did not influence the extraction of Cu and enhanced the phytoextraction of Cd, which was probably related to the high chloride content of the reclaimed water. Our results demonstrate that flood-irrigation with reclaimed water was a successful treatment to grow willows in a dry climate. However, the reclaimed water can also change biosolids properties, which will influence the effectiveness of willows to extract different metals. Copyright © 2015 Elsevier Ltd. All rights

  9. Moderator clean-up system in a heavy water reactor

    International Nuclear Information System (INIS)

    Sasada, Yasuhiro; Hamamura, Kenji.

    1983-01-01

    Purpose: To decrease the fluctuation of the poison concentration in heavy water moderator due to a heavy water clean-up system. Constitution: To a calandria tank filled with heavy water as poison-containing moderators, are connected both end of a pipeway through which heavy water flows and to which a clean-up device is provided. Strongly basic resin is filled within the clean-up device and a cooler is disposed to a pipeway at the upstream of the clean-up device. In this structure, the temperature of heavy water at the inlet of the clean-up device at a constant level between the temperature at the exit of the cooler and the lowest temperature for the moderator to thereby decrease the fluctuation in the poison concentration in the heavy water moderator due to the heavy water clean-up device. (Moriyama, K.)

  10. Future trends in heavy water production

    International Nuclear Information System (INIS)

    Galley, M.R.

    1983-10-01

    World heavy water production has spanned nearly fifty years and, for much of that period, the commodity was often in short supply, but that situation has changed, at least in Canada. There are now adequate reserves of heavy water and sufficient installed production capacity to service Canadian domestic and export demands for the next ten years or beyond. More than 90 percent of the world's inventory of heavy water has been produced by the GS process but this may not be the method that is chosen when the time comes to expand heavy water production again. Other countries, such as India and Argentina, have already chosen ammonia-hydrogen exchange as an alternative technology for part of their domestic production programs. Despite the present surplus of heavy water, research and development of new technologies is very active, particularly in Canada and Japan, because it is recognized that there are still attractive opportunities for future production by processes that are both less expensive and environmentally more acceptable, than either the demonstrated GS process or ammonia-hydrogen alternative. This paper describes the prospects for some of these new processes, contrasts them with the present established methods and assesses the probable impact on the future supply situation

  11. Water issues associated with heavy oil production.

    Energy Technology Data Exchange (ETDEWEB)

    Veil, J. A.; Quinn, J. J.; Environmental Science Division

    2008-11-28

    Crude oil occurs in many different forms throughout the world. An important characteristic of crude oil that affects the ease with which it can be produced is its density and viscosity. Lighter crude oil typically can be produced more easily and at lower cost than heavier crude oil. Historically, much of the nation's oil supply came from domestic or international light or medium crude oil sources. California's extensive heavy oil production for more than a century is a notable exception. Oil and gas companies are actively looking toward heavier crude oil sources to help meet demands and to take advantage of large heavy oil reserves located in North and South America. Heavy oil includes very viscous oil resources like those found in some fields in California and Venezuela, oil shale, and tar sands (called oil sands in Canada). These are described in more detail in the next chapter. Water is integrally associated with conventional oil production. Produced water is the largest byproduct associated with oil production. The cost of managing large volumes of produced water is an important component of the overall cost of producing oil. Most mature oil fields rely on injected water to maintain formation pressure during production. The processes involved with heavy oil production often require external water supplies for steam generation, washing, and other steps. While some heavy oil processes generate produced water, others generate different types of industrial wastewater. Management and disposition of the wastewater presents challenges and costs for the operators. This report describes water requirements relating to heavy oil production and potential sources for that water. The report also describes how water is used and the resulting water quality impacts associated with heavy oil production.

  12. The simulation of stationary and non-stationary regime operation of heavy water production facilities

    International Nuclear Information System (INIS)

    Peculea, M.; Beca, T.; Constantinescu, D.M.; Dumitrescu, M.; Dimulescu, A.; Isbasescu, G.; Stefanescu, I.; Mihai, M.; Dogaru, C.; Marinescu, M.; Olariu, S.; Constantin, T.; Necula, A.

    1995-01-01

    This paper refers to testing procedures of the production capacity of heavy water production pilot, industrial scale plants and of heavy water reconcentration facilities. Simulation codes taking into account the mass and heat transfers inside the exchange columns were developed. These codes provided valuable insight about the isotope build-up of the installation which allowed estimating the time of reaching the stationary regime. Also transient regimes following perturbations in the operating parameters (i.e. temperature, pressure, fluid rates) of the installation were simulated and an optimal rate of routine inspections and adjustments was thus established

  13. Industrial water treatment with heavy metals through zeolites and bioremediation systems with aquatic plants especially Eichhornia crassipes. State of art review

    Directory of Open Access Journals (Sweden)

    Uriel Fernando Carreño-Sayago

    2014-12-01

    Full Text Available In this review we explore different opportunities to use a cheap natural material for removing and retention of heavy metals from polluted waters by waste of different processes. Two research systems will be addressed: the first through a material known as zeolite or more generally porous  luminosilicates, which may be synthesized or extracted from the mines of clays and minerals, being used in its natural state or after modification processes and doping. The other mechanism is bioremediation through algae, some bacteria and especially aquatic plants such as Eichhornia crassipes (water hyacinth. We will evaluate the viability of joining these two types complementing each other. Investigations into the feasibility of Eichhornia crassipes (water hyacinth as feedstock for biofuels are also reviewed.

  14. Advances in commercial heavy water reactor power stations

    International Nuclear Information System (INIS)

    Brooks, G.L.

    1987-01-01

    Generating stations employing heavy water reactors have now firmly established an enviable record for reliable, economic electricity generation. Their designers recognize, however, that further improvements are both possible and necessary to ensure that this reactor type remains attractively competitive with alternative nuclear power systems and with fossil-fuelled generation plants. This paper outlines planned development thrusts in a number of important areas, viz., capital cost reduction, advanced fuel cycles, safety, capacity factor, life extension, load following, operator aida, and personnel radiation exposure. (author)

  15. Ultrasonic relaxation studies associated with n-octylamine-heavy water

    International Nuclear Information System (INIS)

    Kor, S.K.; Singh, R.K.

    1994-01-01

    Ultrasonic absorption measurements have been carried out in lyotropic liquid crystalline system n-octylamine/heavy water in the frequency range 5-65 MHz and at temperatures 30 degC and 37 degC at different concentrations of heavy water in octylamine. Velocity has been measured using interferometric technique at 2 MHz at different concentrations of heavy water. Ultrasonic absorption coefficients at different concentrations in the concentration range 0.3-0.9 m.f. heavy water have been found to show a maxima in the absorption curve at critical concentration (∼0.85 m.f. heavy water). This peak has been found to shift towards lower concentrations of heavy water at higher frequencies. Results have been analysed and it has been found that single relaxation process takes place around 30 MHz and this has been attributed to aggregation of octylamine and heavy water molecules. (author). 8 refs., 6 figs., 3 tabs

  16. Heavy metal accumulation imparts structural differences in fragrant Rosa species irrigated with marginal quality water.

    Science.gov (United States)

    Ahsan, Muhammad; Younis, Adnan; Jaskani, Muhammad Jafar; Tufail, Aasma; Riaz, Atif; Schwinghamer, Timothy; Tariq, Usman; Nawaz, Fahim

    2018-09-15

    Wastewater is an alternative to traditional sources of renewable irrigation water in agriculture, particularly in water-scarce regions. However, the possible risks due to heavy metals accumulation in plant tissues are often overlooked by producers. The present study aimed to identify heavy metals-induced structural modifications to roots of scented Rosa species that were irrigated with water of marginal quality. The chemical and mineral contents from the experimental irrigation canal water (control) and treated wastewater were below the limits recommended by the Pakistan Environmental Protection Agency (Pak-EPA) for medicinal plants. The experimentally untreated wastewater contained electrical conductivity (EC), chemical oxygen demand (COD), biological oxygen demand (BOD), and heavy metals (Co, Cu, Cd, Pb) that were above the recommended limits. The responses by wastewater-treated Rosa species (Rosa damascena, R. bourboniana, R. Gruss-an-Teplitz, and R. centifolia) were evaluated. The experimental data revealed that treated wastewater significantly increased the thickness of collenchyma (cortex and pith) and parenchyma tissues (vascular bundle, xylem, and phloem) of R. Gruss-an-Teplitz. Root dermal tissues (epidermis) of R. bourboniana also responded to treated wastewater. R. damascena and R. centifolia were the least affected species, under the experimental irrigation conditions. Collenchyma and dermal tissues were thicker in R. damascena and R. Gruss-an-Teplitz under untreated wastewater conditions. In parenchyma tissues, vascular bundles were thicker in R. damascena in untreated wastewater conditions, while the xylem and phloem of R. Gruss-an-Teplitz were thicker where treated wastewater was applied. In tissues other than the vascular bundle, the differences in anatomical metrics due to the experimental irrigation treatments were greater during the second year of the experiment than in the first year. The contents of metals other than chromium in the roots and

  17. A study of Cirus heavy water system isotopic purity

    International Nuclear Information System (INIS)

    Thomas, Shibu; Sahu, A.K.; Unni, V.K.P.; Pant, R.C.

    2000-01-01

    Cirus uses heavy water as moderator and helium as cover gas. Approximately one tonne of heavy water was added to the system every year for routine make up. Isotopic purity (IP) of this water used for addition was always higher than that of the system. Though this should increase IP of heavy water in the system, it has remained almost at the same level, over the years. A study was carried out to estimate the extent of improvement in IP of heavy water in the system that should have occurred because of this and other factors in last 30 years. Reasons for non-occurrence of such an improvement were explored. Ion exchange resins used for purification of heavy water and air ingress into helium cover gas system appear to be the principal sources of entry of light water into heavy water system. (author)

  18. Heavy water leak detection using diffusion sampler

    International Nuclear Information System (INIS)

    Joshi, M.L.; Hussain, S.A.

    1990-01-01

    In the Pressurrised Heavy Water Reactors (PHWRs) detection of the sources of heavy water leaks is importent both for the purpose of radiation hazard control as well as for the reduction of escape/loss of heavy water which, is an expensive nuclear material. This paper describes an application of tritium diffusion sampler for heavy water leak detection. The diffusion sampler comprises an usual tritium counting glass vial with a special orifice. The counting vial has water vapour, deficient in HTO concentration. The HTO present outside diffuses in the vial through the orifice, gets exchanged with water of the wet filter paper kept at the bottom and the moisture in the vial atmosphere which has HTO concentration lower than that outside. This results in continuation of net movement of HTO in the vial. The exchanged tritium is counted in liquid scintillation spectrometer. The method has a sensitivity of 10000 dpm/DAC-h. (author). 2 figs., 2 ta bs

  19. Numerical analysis and optimisation of heavy water upgrading column

    International Nuclear Information System (INIS)

    Sankar, Rama; Ghosh, Brindaban; Bhanja, K.

    2013-01-01

    In the 'Pressurised Heavy Water' type of reactors, heavy water is used both as moderator and coolant. During operation of reactor downgraded heavy water is generated that needs to be upgraded for reuse in the reactor. When the isotopic purity of heavy water becomes less than 99.75%, it is termed as downgraded heavy water. Downgraded heavy water also contains impurity such as corrosion products, dirt, oil etc. Upgradation of downgraded heavy water is normally done in two steps: (i) Purification: In this step downgraded heavy water is first purified to remove corrosion products, dirt, oil, etc. and (ii) Upgradation of heavy water to increase its isotopic purity, this step is carried out by vacuum distillation of downgraded heavy water after purification. This project is aimed at mathematical modelling and numerical simulation of heavy water upgrading column. Modelling and simulation studies of the upgradation column are based on equilibrium stage model to evaluate the effect of feed location, pressure, feed composition, reflux ratio in the packed column for given reboiler and condenser duty of distillation column. State to stage modelling of two-phase two-component flow has constitutes the overall modelling of the column. The governing equations consist of stage-wise species and overall mass continuity and stage-wise energy balance. This results in tridigonal matrix equation for stage liquid fractions for heavy and light water. The stage-wise liquid flow rates and temperatures are governed by stage-wise mass and energy balance. The combined form of the corresponding governing equations, with the incorporation of thermodynamic equation of states, form a system of nonlinear equations. This system have been resolved numerically using modified Newton-Raphson method. A code in the MATLAB platform has been developed by on above numerical procedure. The optimisation of the column operating conditions is to be carried out based on parametric studies and analysis of different

  20. Topical and working papers on heavy water accountability and safeguards

    International Nuclear Information System (INIS)

    This report contains the following papers: 1) Statement of IAEA concerning safeguarding of heavy water; 2) Preliminary Canadian Comments on IAEA document on heavy water safeguards; 3) Heavy water accountability 03.10.78; 4) Heavy water accountability 05.04.79

  1. Heavy Metal Polluted Soils: Effect on Plants and Bioremediation Methods

    Directory of Open Access Journals (Sweden)

    G. U. Chibuike

    2014-01-01

    Full Text Available Soils polluted with heavy metals have become common across the globe due to increase in geologic and anthropogenic activities. Plants growing on these soils show a reduction in growth, performance, and yield. Bioremediation is an effective method of treating heavy metal polluted soils. It is a widely accepted method that is mostly carried out in situ; hence it is suitable for the establishment/reestablishment of crops on treated soils. Microorganisms and plants employ different mechanisms for the bioremediation of polluted soils. Using plants for the treatment of polluted soils is a more common approach in the bioremediation of heavy metal polluted soils. Combining both microorganisms and plants is an approach to bioremediation that ensures a more efficient clean-up of heavy metal polluted soils. However, success of this approach largely depends on the species of organisms involved in the process.

  2. High conversion heavy water moderated reactor

    International Nuclear Information System (INIS)

    Miyawaki, Yoshio; Wakabayashi, Toshio.

    1989-01-01

    In the present invention, fuel rods using uranium-plutonium oxide mixture fuels are arranged in a square lattice at the same pitch as that in light water cooled reactor and heavy water moderators are used. Accordingly, the volume ratio (Vm/Vf) between the moderator and the fuel can be, for example, of about 2. When heavy water is used for the moderator (coolant), since the moderating effect of heavy water is lower than that of light water, a high conversion ratio of not less than 0.8 can be obtained even if the fuel rod arrangement is equal to that of PWR (Vm/Vf about 2). Accordingly, it is possible to avoid problems caused by dense arrangement of fuel rods as in high conversion rate light water cooled reactors. That is, there are no more troubles in view of thermal hydrodynamic characteristics, re-flooding upon loss of coolant accident, etc., as well as the fuel production cost is not increased. (K.M.)

  3. Heavy water production benefits of a supporting r and d program

    International Nuclear Information System (INIS)

    Bancroft, A.R.; Chuang, K.T.; Dalrymple, D.G.

    1981-01-01

    Considerable economic benefit was obtained from an active R and D program while the Canadian heavy water plants were brought to mature operation during the 1970s. The introduction to Canada of this new chemical processing industry led to unexpected process, equipment and materials problems. Having a small team of technical experts already working on heavy water processes and a much larger R and D team working in related fields allowed a rapid response to the problems that limited production. The number of engineers and scientists working on the GS process rose rapidly from a skeleton team in 1970 to 54 during 1974. Effort declined steadily as the major problems were solved and reached 22 by 1980. Cumulative effort over the decade was 264 man-years at a cost of 3.3 percent of the value of the heavy water produced. The new production benefits have lagged behind the R and D expenditure by a few years and the current spending rate is 1.2 percent of product value. Important contributions were made in the areas of process simulation, process chemistry, materials of construction, sieve trays, and mechanical equipment

  4. Heavy Metal Displacement in Chelate-Assisted Phytoremediation of Biosolids Soil

    Science.gov (United States)

    Kirkham, M. B.; Liphadzi, M. S.

    2005-05-01

    Heavy metals in biosolids (sewage sludge) applied to land contaminate the soil. Phytoremediation, the use of plants to clean up toxic heavy metals, might remove them. Chelating agents are added to soil to solubilize the metals for enhanced phytoextraction. Yet no studies follow the displacement and leaching of heavy metals in soil with biosolids following solubilization with chelates. The objective of this work was to determine the mobility of heavy metals, as affected by a chelate, in soil (Haynie very fine sandy loam) from a 25-year old sludge farm. Soil columns (105 cm long; 39 cm in diameter) either had a plant (hybrid poplar; Populus deltoides Marsh. x P. nigra L.) or no plant. When the poplars were 144 days old, the tetrasodium salt of the chelating agent EDTA (ethylenediamine-tetraacetic acid) was irrigated onto the soil at a rate of 1 g per kg of soil. Drainage water, soil, and plants were analyzed for three toxic heavy metals (Cd, Ni, Pb) and four essential heavy metals (Cu, Fe, Mn, Zn). Without EDTA, concentrations of the seven heavy metals in the leachate from columns with or without plants were low or below detection limits. With or without plants, the EDTA mobilized all heavy metals and increased their concentration in drainage water. Without plants, the concentrations of Cd, Cu, Fe, Pb, and Zn in the leachate from columns with EDTA were above drinking-water standards. (There is no drinking-water standard for Ni.) The presence of poplar plants in the soil reduced the concentrations of Cu, Fe, and Zn in the leachate so it fell within drinking-water standards. Concentrations of Cd and Pb in the leachate remained above drinking-water standards with or without plants. At harvest (124 days after the EDTA application), total concentration of each heavy metal in the soil at different depths in the columns with EDTA was similar to that in the columns without EDTA. The chelate did not affect the concentration of heavy metals in the roots, stems, or leaves

  5. Development of the heavy-water organic-cooled reactor. Status report from the United States of America

    Energy Technology Data Exchange (ETDEWEB)

    Trilling, C A [Atomics International, Division of North American Aviation, Inc., Canoga Park, CA (United States)

    1967-01-01

    In late 1964 the United States Atomic Energy Commission decided to undertake the development of the heavy-water-moderated nuclear power reactor as part of its overall programme for the development of advanced converter reactors. The inclusion of the heavy-water reactor concept was based on its indicated potential for achieving: efficient utilization of available fuel resources; generation of low cost electric power; feasibility of scale-up to very large single unit plant sizes for the dual purpose of generating power and desalting sea water. The excellent neutron economy inherent in heavy-water moderation allows a significant increase in the amount of power which can be generated from a given amount of ore. If one takes into account the amount of uranium required not only for burn-up but also to inventory new reactors in a rapidly expanding nuclear economy, heavy-water reactors show the potential of extracting one and a half to two times more power from the ore mined than light-water reactors. Such an improvement in dynamic fuel utilization will postpone the depletion of low cost uranium ore reserves, providing more time for the discovery of new ore resources and the development of economic fast breeder reactors. The excellent neutron economy of the heavy-water reactor also allows the achievement of appreciable burn-up with low enrichment fuel, with consequent low fuel cycle costs and therefore low energy generation costs. These low fuel cycle costs make the economics of this type of reactor rather insensitive to rising ore costs. They also make the concept well suited for the most economic production of the large quantities of heat required for water desalination. The use of individual pressure tubes for circulating the coolant through the reactor vessel lends itself to the development of a modular type design, which can be scaled up to very large single unit plant sizes by simply increasing the number of identical pressure tube modules and the number of coolant

  6. Comparative Study of Heavy Metals in Soil and Selected Medicinal Plants

    Directory of Open Access Journals (Sweden)

    Afzal Shah

    2013-01-01

    Full Text Available Essential and nonessential heavy metals like iron (Fe, nickel (Ni, manganese (Mn, zinc (Zn, copper (Cu, cadmium (Cd, chromium (Cr, and lead (Pb were analyzed in four selected medicinal plants such as Capparis spinosa, Peganum harmala, Rhazya stricta, and Tamarix articulata by flame atomic absorption spectrophotometer (FAAS. These medicinal plants are extensively used as traditional medicine for treatment of various ailments by local physicians in the area from where these plants were collected. The concentration level of heavy metals in the selected plants was found in the decreasing order as Fe > Zn > Mn > Cu > Ni > Cr > Cd > Pb. The results revealed that the selected medicinal plants accumulate these elements at different concentrations. Monitoring such medicinal plants for heavy metals concentration is of great importance for physicians, health planners, health care professionals, and policymakers in protecting the public from the adverse effects of these heavy metals.

  7. Ultrasonic measurements for in-service assessment of wrought Inconel 625 cracker tubes of heavy water plants

    International Nuclear Information System (INIS)

    Kumar, Anish; Rajkumar, K.V.; Jayakumar, T.; Raj, Baldev; Mishra, B.

    2006-01-01

    The degradation in mechanical properties of Inconel 625 ammonia cracker tubes occurs during the service for long duration in heavy water plants. The present study brings out the possibility of using Poisson's ratio (derived from measurement of time of flight of ultrasonic waves) in combination with hardness measurements, as an effective non-destructive tool for assessment of in-service degradation of Inconel 625 cracker tubes and qualification of re-solution annealing heat treatment for their rejuvenation. Further, the study also indicates the feasibility of extending the life of some of the tubes beyond the presently followed 120 000 h, before they are taken up for re-solution annealing, without affecting their serviceability. However, further studies are required to identify quantitative criterion for Poisson's ratio and hardness values, for deciding on the basis for removal of the tubes for rejuvenation

  8. Heavy water lattices: Second panel report

    International Nuclear Information System (INIS)

    1963-01-01

    The panel was attended by prominent physicists from most of the laboratories engaged in the field of heavy water lattices throughout the world. The participants presented written contributions and status reports describing the past history and plans for further development of heavy-water reactors. Valuable discussions took place, during which recommendations for future work were formulated. Refs, figs, tabs

  9. Heavy water lattices: Second panel report

    Energy Technology Data Exchange (ETDEWEB)

    1963-09-15

    The panel was attended by prominent physicists from most of the laboratories engaged in the field of heavy water lattices throughout the world. The participants presented written contributions and status reports describing the past history and plans for further development of heavy-water reactors. Valuable discussions took place, during which recommendations for future work were formulated. Refs, figs, tabs.

  10. A review of phytoremediation technology: heavy metals uptake by plants

    Science.gov (United States)

    Sumiahadi, A.; Acar, R.

    2018-03-01

    Heavy metal is one of the serious environmental pollutions for now days as impact of industrial development in several countries. Heavy metals give toxic effects on human health and cause several serious diseases. Several techniques have been using for removing heavy metal contaminants from the environmental but these techniques have limitations such as high cost, long time, logistical problems and mechanical complexity. Phytoremediation can be used as an alternative solution for heavy metal remediation process because of its advantages as a cost-effective, efficient, environment- and eco-friendly technology based on the use of metal-accumulating plants. According to previous studies, several plants have a high potential as heavy metals bioaccumulator and can be used for phytoremediation process of heavy metals.

  11. Heavy water: a distinctive and essential component of CANDU

    International Nuclear Information System (INIS)

    Miller, A.I.; van Alstyne, H.M.

    1994-06-01

    The exceptional properties of heavy water as a neutron moderator provide one of the distinctive features of CANDU reactors. Although most of the chemical and physical properties of deuterium and protium (mass 1 hydrogen) are appreciably different, the low terrestrial abundance of deuterium makes the separation of heavy water a relatively costly process, and so of considerable importance to the CANDU system. World heavy-water supplies are currently provided by the Girdler-Sulphide process or processes based on ammonia-hydrogen exchange. Due to cost and hazard considerations, new processes will be required for the production of heavy water in and beyond the next decade. Through AECL's development and refinement of wetproofed catalysts for the exchange of hydrogen isotopes between water and hydrogen, a family of new processes is expected to be deployed. Two monothermal processes, CECE (Combined Electrolysis and Catalytic Exchange, using water-to-hydrogen conversion by electrolysis) and CIRCE (Combined Industrially Reformed hydrogen and Catalytic Exchange, based on steam reforming of hydrocarbons), are furthest advanced. Besides its use for heavy-water production, the CECE process is a highly effective technology for heavy-water upgrading and for tritium separation from heavy (or light) water. (author). 10 refs., 1 tab., 7 figs

  12. Covariance of oxygen and hydrogen isotopic composition in plant water: Species effects

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, L.W.; DeNiro, M.J. (Univ. of California, Los Angeles (United States))

    1989-12-01

    Leaf water becomes enriched in the heavy isotopes of oxygen and hydrogen during evapotranspiration. The magnitude of the enrichment has been shown to be influenced by temperature and humidity, but the effects of species-specific factors on leaf water enrichment of D and {sup 18}O have not been studied for different plants growing together. To learn whether leaf water enrichment patterns and processes for D and {sup 18}O are different for individual species growing under the same environmental conditions the authors tested the proposal that leaf waters in plants with crassulacean acid metabolism (CAM) show high sloped (m in the leaf water equation {delta}D = m {delta}{sup 18}O + b) than in C{sub 3} plants. They determined the relationships between the stable hydrogen ({delta}D) and oxygen ({delta}{sup 18}O) isotope ratios of leaf waters collected during the diurnal cycle of evapotranspiration for Yucca schidigera, Ephedra aspera, Agave deserti, Prunus ilicifolia, Yucca whipplei, Heteromeles arbutifolia, Dyckia fosteriana, Simmondsia chinensis, and Encelia farinosa growing at two sites in southern California. The findings indicate that m in the aforementioned equation is related to the overall residence time for water in the leaf and proportions of water subjected to repeated evapotranspiration enrichments of heavy isotopes.

  13. Eliminating Heavy Metals from Water with NanoSheet Minerals as Adsorbents

    Directory of Open Access Journals (Sweden)

    Shaoxian Song

    2017-12-01

    Full Text Available Heavy metals usually referred to those with atomic weights ranging from 63.5 to 200.6. Because of natural-mineral dissolution and human activities such as mining, pesticides, fertilizer, metal planting and batteries manufacture, etc., these heavy metals, including zinc, copper, mercury, lead, cadmium and chromium have been excessively released into water courses, like underground water, lake and river, etc. The ingestion of the heavy metals-contaminated water would raise serious health problems to human beings even at a low concentration. For instance, lead can bring human beings about barrier to the normal function of kidney, liver and reproductive system, while zinc can cause stomach cramps, skin irritations, vomiting and anemia. Mercury is a horrible neurotoxin that may result in damages to the central nervous system, dysfunction of pulmonary and kidney, chest and dyspnea. Chromium (VI has been proved can cause many diseases ranging from general skin irritation to severe lung carcinoma. Accordingly, the World Health Organization announced the maximum contaminant levels (MCL for the heavy metals in drinking water. There are numerous processes for eliminating heavy metals from water in order to provide citizens safe drinking water, including precipitation, adsorption, ion exchange, membrane separation and biological treatment, etc. Adsorption is considered as a potential process for deeply removing heavy metals, in which the selection of adsorbents plays a predominant role. Nano-sheet minerals as the adsorbents are currently the hottest researches in the field. They are obtained from layered minerals, such as montmorillonite, graphite and molybdenite, through the processing of intercalation, electrochemical and mechanical exfoliation, etc. Nano-sheet minerals are featured by their large specific surface area, relatively low costs and active adsorbing sites, leading to be effective and potential adsorbents for heavy metals removal from water

  14. Instrumentation and signal processing for the detection of heavy water using off axis-integrated cavity output spectroscopy technique

    Science.gov (United States)

    Gupta, A.; Singh, P. J.; Gaikwad, D. Y.; Udupa, D. V.; Topkar, A.; Sahoo, N. K.

    2018-02-01

    An experimental setup is developed for the trace level detection of heavy water (HDO) using the off axis-integrated cavity output spectroscopy technique. The absorption spectrum of water samples is recorded in the spectral range of 7190.7 cm-1-7191.5 cm-1 with the diode laser as the light source. From the recorded water vapor absorption spectrum, the heavy water concentration is determined from the HDO and water line. The effect of cavity gain nonlinearity with per pass absorption is studied. The signal processing and data fitting procedure is devised to obtain linear calibration curves by including nonlinear cavity gain effects into the calculation. Initial calibration of mirror reflectivity is performed by measurements on the natural water sample. The signal processing and data fitting method has been validated by the measurement of the HDO concentration in water samples over a wide range from 20 ppm to 2280 ppm showing a linear calibration curve. The average measurement time is about 30 s. The experimental technique presented in this paper could be applied for the development of a portable instrument for the fast measurement of water isotopic composition in heavy water plants and for the detection of heavy water leak in pressurized heavy water reactors.

  15. Process for the extraction of tritium from heavy water

    International Nuclear Information System (INIS)

    Dombra, A.H.

    1984-01-01

    The object of the invention is achieved by a process for the extraction of tritium from a liquid heavy water stream comprising: contacting the heavy water with a countercurrent gaseous deuterium stream in a column packed with a water-repellent catalyst such that tritium is transferred by isotopic exchange from the liquid heavy water stream to the gaseous deuterium stream

  16. Method of operating heavy water moderated reactors

    International Nuclear Information System (INIS)

    Masuda, Hiroyuki.

    1980-01-01

    Purpose: To enable stabilized reactor control, and improve the working rate and the safety of the reactor by removing liquid poison in heavy water while maintaining the power level constant to thereby render the void coefficient of the coolants negative in the low power operation. Method: The operation device for a heavy water moderated reactor comprises a power detector for the reactor, a void coefficient calculator for coolants, control rods inserted into the reactor, a poison regulator for dissolving poisons into or removing them out of heavy water and a device for removing the poisons by the poison regulator device while maintaining the predetermined power level or inserting the control rods by the signals from the power detector and the void coefficient calculator in the high temperature stand-by conditions of the reactor. Then, the heavy water moderated reactor is operated so that liquid poisons in the heavy water are eliminated in the high temperature stand-by condition prior to the start for the power up while maintaining the power level constant and the plurality of control rods are inserted into the reactor core and the void coefficient of the coolants is rendered negative in the low power operation. (Seki, T.)

  17. Heavy water pumps; Pumpe D{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Zecevic, V; Nikolic, M

    1963-12-15

    Continuous increase of radiation intensity was observed on all the elements in the heavy water system during first three years of RA reactor operation. The analysis of heavy water has shown the existence of radioactive cobalt. It was found that cobalt comes from stellite, cobalt based alloy which was used for coating of the heavy water pump discs in order to increase resistance to wearing. Cobalt was removed from the surfaces due to friction, and transferred by heavy water into the reactor where it has been irradiated for 29 876 MWh up to 8-15 Ci/g. Radioactive cobalt contaminated all the surfaces of aluminium and stainless steel parts. This report includes detailed description of heavy water pumps repair, exchange of stellite coated parts, decontamination of the heavy water system, distillation of heavy water. [Serbo-Croat] U toku prve tri godine eksploatacije reaktora RA uocen je neprekidni porast intenziteta zracenja na svim elementima u teskovodnom sistemu. Analizom teske vode utvrdjeno je postojanje radioaktivnog kobalta. Ustanovljeno je da kobalt potice od stelita, legure na bazi kobalta kojim su presvuceni rukavci vratila teskovodnih pumpi radi otpornosi na habanje. Kobalt je trenjem skidan sa povrsina, u toku rada prenosen je teskom vodom u reaktor i ozracivan u toku 29 876 MWh do specificne aktivnosti 8-15 Ci/g. Radioaktivni kobalt je kontaminirao sve povrsine od aluminijuma i nerdjajuceg celika. Ovaj izvestaj sadrzi detaljan opis remonta pumpi, zamene delova teskovodnih pumpi novim delovima bez stelitnog sloja, dekontaminacije teskovodnog sistema, destilacije teske vode.

  18. Covariance of oxygen and hydrogen isotopic compositions in plant water: species effects

    International Nuclear Information System (INIS)

    Cooper, L.W.; DeNiro, M.J.

    1989-01-01

    Leaf water becomes enriched in the heavy isotopes of oxygen and hydrogen during evapotranspiration. The magnitude of the enrichment has been shown to be influenced by temperature and humidity, but the effects of species—specific factors on leaf water enrichment of D and 18 O have not been studied for different plants growing together. Accordingly, to learn whether leaf water enrichment patterns and processes for D and 18 O are different for individual species growing under the same environmental conditions we tested the proposal that leaf waters in plants with crassulacean acid metabolism (CAM) show higher slopes (m in the leaf water equation °D = m ° 18 O + b) than in C 3 plants. We determined the relationships between the stable hydrogen (°D) and oxygen (° 18 O) isotope ratios of leaf waters collected during the diurnal cycle of evapotranspiration for Yucca schidigera, Ephedra aspera, Agave deserti, Prunus ilicifolia, Yucca whipplei, Heteromeles arbutifolia, Dyckia fosteriana, Simmondsia chinensis, and Encelia farinosa growing at two sites in southern California. Slopes (m in the above leaf water equation) ranged from 1.50 to 3.21, compared to °8 for meteoric water, but differences in slope could not be attributed to carboxylation pathway (CAM vs. C 3 ) nor climate (coastal California vs. Sonoran Desert). Higher slopes were correlated with greater overall ranges of leaf water enrichment of D and 18 O. Water in plants with higher slopes also differed most from unaltered meteoric water. Leaf water isotope ratios in plants with lower slopes were better correlated with temperature and humidity. The findings indicate that m in the aforementioned equation is related to the overall residence time for water in the leaf and proportions of water subjected to repeated evapotranspiration enrichments of heavy isotopes

  19. Investigation of heavy metals content in medicinal plant, eclipta alba L

    International Nuclear Information System (INIS)

    Hussain, I.; Khan, H.

    2010-01-01

    Heavy metal such as Cr, Fe, Zn, Mn, Ni, Pb, Cu and Cd were investigated in a= medicinally important plant, Eclipta alba L. as well as in the soil it was grown using atomic absorption spectrophotometer. The plant samples were collected from their natural habitat at three different locations of Peshawar Pakistan. The whole plant materials (roots, stems and leaves) were found to contain all heavy metals except Cd, which corresponds to their concentration in the soil it was grown. Among all the heavy metals, Fe was found to be at the highest level (8.95 to 27.7 mg/kg) followed by Mn (0.44 to 14.0 mg/kg) and Zn (1.04 to 4.50 mg/kg), while the rest of metals were at low concentration. The present study showed that E. alba L. is suitable for the control of environmental pollutants such as heavy metals, however, for medicinal purposes; it should be collected from those areas which are not contaminated with heavy metals. The purpose of the current study was to standardize various indigenous medicinal plants for heavy metals contamination and to make awareness among the public regarding its safer use and collection areas, containing high level of heavy metals and their adverse health affects. (author)

  20. Probabilistic consequence assessment of hydrogen sulphide releases from a heavy water plant

    International Nuclear Information System (INIS)

    1983-06-01

    This report is the second in a series concerned with the evaluation of the consequences to the public of an accidental release of hydrogen sulphide (H 2 S) to the atmosphere following a pipe or pressure envelope failure, or some other process upset, at a heavy water plant. It consists of documentation of the code GASPROB, which has been developed to provide consequence probabilities for a range of postulated releases. The code includes mathematical simulations of initial gas behaviour upon release to the atmosphere, such as gravitational settling of a cold release and the rise of jets and flares, subsequent atmospheric dispersion under a range of weather conditions, and the toxic effects on the exposed population. The code makes use of the site-specific dispersion climatology, topography and population distribution, as well as the probabilistic lethal dose data for the released gas. Output for a given postulated release can be provided in terms of the concentration of the gas at ground level around the point of release, projected numbers of fatalities within specified areas and the projected total fatalities regardless of location. This report includes a general description of GASPROB, and specifics of the code structure, the function of each subroutine, input and output data, and the permanent data files established. Three appendices to the report contain a complete code listing, detailed subroutine descriptions and a sample output

  1. A Drinking Water Sensor for Lead and Other Heavy Metals.

    Science.gov (United States)

    Lin, Wen-Chi; Li, Zhongrui; Burns, Mark A

    2017-09-05

    Leakage of lead and other heavy metals into drinking water is a significant health risk and one that is not easily detected. We have developed simple sensors containing only platinum electrodes for the detection of heavy metal contamination in drinking water. The two-electrode sensor can identify the existence of a variety of heavy metals in drinking water, and the four-electrode sensor can distinguish lead from other heavy metals in solution. No false-positive response is generated when the sensors are placed in simulated and actual tap water contaminated by heavy metals. Lead detection on the four-electrode sensor is not affected by the presence of common ions in tap water. Experimental results suggest the sensors can be embedded in water service lines for long-time use until lead or other heavy metals are detected. With its low cost (∼$0.10/sensor) and the possibility of long-term operation, the sensors are ideal for heavy metal detection of drinking water.

  2. Water use, productivity and interactions among desert plants

    Energy Technology Data Exchange (ETDEWEB)

    Ehleringer, J.R.

    1992-11-17

    Productivity, stability, and competitive interactions among ecosystem components within aridlands are key processes related directly to water in deserts. This project assumes that integrated aspects of plant metabolism provide insight into the structure and function of plant communities and ecosystems. While it is difficult to extrapolate from instantaneous physiological observations to higher scales, such as whole plant performance or to the interactions between plants as components of ecosystems, several key aspects of plant metabolism are scalable. Analyses of stable isotopic composition in plant tissues at natural abundance levels provide a useful tool that can provide insight into the consequences of physiological processes over temporal and spatial scales. Some plant processes continuously fractionate among light and heavy stable isotopic forms of an element; over time this results in integrated measures of plant metabolism. For example, carbon isotope fractionation during photosynthesis results in leaf carbon isotopic composition that is a measure of the set-point for photosynthetic metabolism and of water-use efficiency. Thus it provides information on the temporal scaling of a key physiological process.

  3. Pollution and ecological risk assessment of heavy metals in the soil-plant system and the sediment-water column around a former Pb/Zn-mining area in NE Morocco.

    Science.gov (United States)

    El Azhari, Abdellah; Rhoujjati, Ali; El Hachimi, Moulay Laârabi; Ambrosi, Jean-Paul

    2017-10-01

    This study discussed the environmental fate and ecological hazards of heavy metals in the soil-plant system and sediment-water column around the former Pb-Zn mining Zeïda district, in Northeastern Morocco. Spatial distribution, pollution indices, and cluster analysis were applied for assessing Pb, Zn, As, Cu and Cd pollution levels and risks. The geo-accumulation index (I geo ) was determined using two different geochemical backgrounds: i) the commonly used upper crust values, ii) local geochemical background calculated with exploratory data analysis. The soils in the vicinity of the tailings, as well as the sediments downstream of the latter, displayed much higher metal concentrations, I geo, and potential ecology risk coefficient values than other sites, classifying these sites as highly contaminated and severely hazardous. The concentrations of Pb in contaminated sediment samples also exceeded the PEC limits and are expected to cause harmful effects on sediment-dwelling organisms. Based on the comparison with the toxicity limits, the most contaminated plant samples were found around the tailings piles. The metal concentrations in both raw and filtrated water samples were overall below the drinking water standards in samples upstream and downstream of the mining center, indicating that heavy metals levels in the Moulouya River surface waters were not affected by the tailings spill. Cluster analysis suggest that: i) Pb and Zn in sediments were derived from the abandoned tailings and are mainly stored and transported as particle-bound to the bedload, ii) Pb, Zn, and Cu in the soil-plant system were related to the dispersion of tailings materials while As and Cd originated primarily from natural geological background in both the soil-plant and the water-sediment systems. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Alkali metal and ammonium chlorides in water and heavy water (binary systems)

    CERN Document Server

    Cohen-Adad, R

    1991-01-01

    This volume surveys the data available in the literature for solid-fluid solubility equilibria plus selected solid-liquid-vapour equilibria, for binary systems containing alkali and ammonium chlorides in water or heavy water. Solubilities covered are lithium chloride, sodium chloride, potassium chloride, rubidium chloride, caesium chloride and ammonium chloride in water and heavy water.

  5. Procedure for operating a heavy water cooled power reactor

    International Nuclear Information System (INIS)

    Rau, P.; Kumpf, H.

    1981-01-01

    Nuclear reactors cooled by heavy water usually have equipment for fuel element exchange during operation, with the primary circuit remaining contained. This fuel element exchange equipment is expensive and complicated in many respects. According to the invention, the heavy water is therefore replaced by light water after a certain time of operation in such way that light water is led in and heavy water is led off. After the replacement, at least a quarter of the fuel elements of the reactor core is exchanged with the reactor pressure vessel being open. Then the light water serving as a shielding is replaced by heavy water, with the reactor pressure vessel being closed. The invention is of interest particularly for high-conversion reactors. (orig.) [de

  6. Heavy-metal-induced reactive oxygen species: phytotoxicity and physicochemical changes in plants.

    Science.gov (United States)

    Shahid, Muhammad; Pourrut, Bertrand; Dumat, Camille; Nadeem, Muhammad; Aslam, Muhammad; Pinelli, Eric

    2014-01-01

    As a result of the industrial revolution, anthropogenic activities have enhanced there distribution of many toxic heavy metals from the earth's crust to different environmental compartments. Environmental pollution by toxic heavy metals is increasing worldwide, and poses a rising threat to both the environment and to human health.Plants are exposed to heavy metals from various sources: mining and refining of ores, fertilizer and pesticide applications, battery chemicals, disposal of solid wastes(including sewage sludge), irrigation with wastewater, vehicular exhaust emissions and adjacent industrial activity.Heavy metals induce various morphological, physiological, and biochemical dysfunctions in plants, either directly or indirectly, and cause various damaging effects. The most frequently documented and earliest consequence of heavy metal toxicity in plants cells is the overproduction of ROS. Unlike redox-active metals such as iron and copper, heavy metals (e.g, Pb, Cd, Ni, AI, Mn and Zn) cannot generate ROS directly by participating in biological redox reactions such as Haber Weiss/Fenton reactions. However, these metals induce ROS generation via different indirect mechanisms, such as stimulating the activity of NADPH oxidases, displacing essential cations from specific binding sites of enzymes and inhibiting enzymatic activities from their affinity for -SH groups on the enzyme.Under normal conditions, ROS play several essential roles in regulating the expression of different genes. Reactive oxygen species control numerous processes like the cell cycle, plant growth, abiotic stress responses, systemic signalling, programmed cell death, pathogen defence and development. Enhanced generation of these species from heavy metal toxicity deteriorates the intrinsic antioxidant defense system of cells, and causes oxidative stress. Cells with oxidative stress display various chemical,biological and physiological toxic symptoms as a result of the interaction between ROS and

  7. Start-up test of the prototype heavy water reactor 'FUGEN', (1)

    International Nuclear Information System (INIS)

    Ando, Hideki; Kawahara, Toshio

    1982-01-01

    The advanced thermal prototype reactor ''Fugen'' is a heavy water-moderated, boiling light water-cooled power reactor with electric output of 165 MW, which has been developed since 1966 as a national project. The start-up test was begun in March, 1978, being scheduled for about one year, and in March, 1979, it passed the final pre-use inspection and began the full scale operation. In this paper, the result of the start-up test of Fugen is reported. From the experience of the start-up test of Fugen, the following matters are important for the execution of start-up test. 1) Exact testing plan and work schedule, 2) the organization to perform the test, 3) the rapid evaluation of test results and the reflection to next testing plan, and 4) the reflection of test results to rated operation, regular inspection and so on. In the testing plan, the core characteristics peculiar to Fugen, and the features of heavy water-helium system, control system and other equipment were added to the contents of the start-up test of BWRs. The items of the start-up test were reactor physics test, plant equipment performance test, plant dynamic characteristic test, chemical and radiation measurement, and combined test. The organization to perform the start-up test, and the progress and the results of the test are reported. (Kako, I.)

  8. Fuel and heavy water availability

    International Nuclear Information System (INIS)

    1980-01-01

    The general guidelines for the Working Group's evaluation of the availability of nuclear fuel and heavy water were set at the Organizing Conference of the International Nuclear Fuel Cycle Evaluation (INFCE), which was held in Washington, United States of America, 19-21 October 1977. The agreed technical and economic scope for the evaluation was to: (1) Estimate needs for nuclear energy and correlated needs for uranium and heavy water according to different fuel cycle strategies; (2) Review uranium availability with specific regard to: Assessment of resources and production capacities; policies and incentives for encouraging exploration and production including joint ventures; marketing policies and/or guarantees of sales for companies investing in exploration and production; marketing policies and/or guarantees of supply for utilities; technical development of exploration, mining and milling methods; (3) Review heavy water availability; (4) Review thorium availability; (5) Consider special needs of developing countries. The illustrations of availability and requirements developed in this report do provide a useful framework for considering future options and alternatives for the development of nuclear power

  9. Aspects regarding the safety improvement by corrosion protection on a GS heavy water plant

    International Nuclear Information System (INIS)

    Nicolaescu, G.V.; Nicolaescu, G.I.; Ohai, D.; Pavelescu, M.

    1995-01-01

    A new procedure to form a protective iron sulfide film in heavy water production columns is described and the results obtained are compared with an older procedure, showing the characteristics of protective film in both cases and the advantages of the new method. (Author)

  10. Production of heavy water by photodesorption

    International Nuclear Information System (INIS)

    Gangwer, T.; Goldstein, M.K.

    1976-01-01

    Research has recently brought attention to the laser as a tool for isotope enrichment. So far the main thrust of this effort has been toward uranium enrichment; however, numerous successes in other areas have been demonstrated. Isotopes of boron, sulfur, chlorine, and carbon have been separated. A new technique is proposed for laser isotope enrichment. The technique, referred to as photodesorption, involves selective isotopic excitation of molecules adsorbed on a surface such that an enrichment results from subsequent physical or chemical events undergone by the excited molecules. The specific processes of concern are the physical photodesorption enrichment of heavy water from light water and tritiated water from heavy water. The ability to work directly with water molecules has significant advantages for a commercial process. A photodesorption enrichment process has been forumulated and some analyses have been performed. This process is described and some preliminary cost estimates are made which assume successful accomplishment of the major R and D objectives of the new process. The results indicate that the process has the promise of a significant reduction in the cost of heavy water and that further study is warranted

  11. Study of minor actinides transmutation in heavy water cooled tight-pitch lattice

    International Nuclear Information System (INIS)

    Xu Xiaoqin; Shiroya, S.

    2002-01-01

    Minor actinides inhere long half-life and high toxicity. It is an alternative technical pathway and helpful for reducing environmental impact to incinerate minor actinides in spent fuel of nuclear power plants. Because of its high neutron, γ and β emitting rates and heat generation rate, it is necessary to imply more severe control and shielding techniques in the chemical treatment and fabrication. From economic view-point, it is suitable to transmute minor actinides in concentrated way. A technique for MA transmutation by heavy water cooled tight-pitch lattice system is proposed, and calculated with SRAC95 code system. It is shown that tight-pitch heavy water lattice can transmute MA effectively. The accelerator-driven subcritical system is practical for MA transmutation because of its low fraction of effective delay neutrons

  12. Topical papers on heavy water, fuel fabrication and reactors

    International Nuclear Information System (INIS)

    1978-01-01

    A total of four papers is presented. The first contribution of the Federal Republic of Germany reviews the market situation for reactors and the relations between reactor producers and buyers as reflected in sales agreements. The second West German contribution gives a world-wide survey of fuel element production as well as of fuel and fuel element demand up to the year 2000. The Canadian paper discusses the future prospects of heavy-water production, while the Ecuador contribution deals with small and medium-sized nuclear power plants

  13. Modification / procedural changes adopted for safe and smooth operation of Heavy Water Plant, Hazira for maximising productivity and resulting in energy conservation (Paper No. 6.6)

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    The Heavy Water Plant at Hazira is based on monothermal ammonia-hydrogen exchange process. The plant is built in two stream for isotopic exchange and enrichment with common facilities for interconnections with fertilizer plant, synthesis unit, amide preparation, utilities and final product, identical to HWP, Thal unit. This plant is built after incorporating some of the improvement effected from operating experiences gained from Baroda, Tuticorin and Thal plants. Plant erection was completed without a single casualty/mishap well within the time schedule and commissioning was completed within six months from charging of synthesis gas and ammonia in the plant. A few modifications of minor/major nature have been incorporated both in the design and during the course of operation. Some procedural changes have also been adopted for flexibility of operation, improved productivity and energy conservation. (author). 2 figs

  14. Standards for heavy water concentration determinations in light water

    International Nuclear Information System (INIS)

    Varlam, M.; Steflea, D.; Pavelescu, M.

    1995-01-01

    The paper presents a method to prepare heavy water -light water standards within the range 144 ppm - 1%. A formula for computing standards concentration based on initial concentration of D 2 O and distilled water is given

  15. Production of heavy water in France

    International Nuclear Information System (INIS)

    Lerat, J.M.; Roth, E.

    1964-01-01

    Since 1958, studies relating to heavy water production have covered several processes. Each one has been examined to a greater or lesser degree and attention has finally been concentrated on the isotopic exchanges between hydrogen sulphide and water and between ammonia and synthesis gas, the pilot experiment having shown that hydrogen distillation, although technologically satisfactory, was not competitive. NH 3 synthesis gas exchange process; 1) Research was continued and led to the decision to build a production unit, devoted also to the synthesis of ammonia. The process essentially depends on the source of the synthesis gas; the use of a H 2 O/H 2 exchange, which could make it independent, has in fact been rejected for economic reasons. Amongst the various possible designs for the process, the one temperature system was chosen, in spite of certain technological problems, because of it provides: a high enrichment with a reduced number of contact devices. These have now been perfected after large-scale pilot tests. The original industrial experiment to be set in operation will supply useful information for second generation plants, whether they use the one temperature lay out again or whether they adopt the two temperature system. H 2 S-H 2 O exchange process. The pilot plant, described in 1958, has been used for a systematic study of corrosion. It was possible to proceed to preliminary specifications of plants, with 2 or 3 H 2 S - H 2 O stages exchange for primary enrichment. They final stage beyond a 10 to 20 p.100 D 2 O concentration being carried out by the distillation of water. Various heat exchange systems have been studied in detail and it was concluded that choices, as for instance the one of optimum division of the cascade, were eventually to be made according to the particular economic conditions of creation at the chosen location of the plant. (author) [fr

  16. Study of essential safety features of a three-loop 1,000 MWe light water reactor (PWR) and a corresponding heavy water reactor (HWR) on the basis of the IAEA nuclear safety standards

    International Nuclear Information System (INIS)

    1989-02-01

    Based on the IAEA Standards, essential safety aspects of a three-loop pressurized water reactor (1,000 MWe) and a corresponding heavy water reactor were studied by the TUeV Baden e.V. in cooperation with the Gabinete de Proteccao e Seguranca Nuclear, a department of the Ministry which is responsible for Nuclear power plants in Portugal. As the fundamental principles of this study the design data for the light water reactor and the heavy water reactor provided in the safety analysis reports (KWU-SSAR for the 1,000 MWe PWR, KWU-PSAR Nuclear Power Plant ATUCHA II) are used. The assessment of the two different reactor types based on the IAEA Nuclear Safety Standards shows that the reactor plants designed according to the data given in the safety analysis reports of the plant manufacturer meet the design requirements laid down in the pertinent IAEA Standards. (orig.) [de

  17. Biosorption of heavy metals and uranium from dilute solutions

    International Nuclear Information System (INIS)

    Schneider, I.A.H.; Misra, M.; Smith, R.W.

    1995-01-01

    Eichhornia crassipes approaches being a scourge in many parts of the world, choking waterways and hindering transport upon them. At the same time it is known to readily abstract heavy metal ions from water and, thus, aids in the removal of heavy metals found in such waters. This paper considers the possibility of using specific parts of the plant as an inexpensive adsorbent for the removal of heavy metals from contaminated chemical and mining industry waste waters. In particular the root of the plant was found to be an excellent accumulator of heavy metal ions including uranium from solution. It is also suggested that dried roots of the plant might be placed in simple bags and used in a very low cost metal ion removal system

  18. Water use, productivity and interactions among desert plants

    Energy Technology Data Exchange (ETDEWEB)

    Ehleringer, J.R.

    1992-11-17

    Water plays a central role affecting all aspects of the dynamics in aridland ecosystems. Productivity, stability, and competitive interactions among ecosystem components within aridlands are key processes related directly to water in deserts. The ecological studies in this project revolve around one fundamental premise: that integrated aspects of plant metabolism provide insight into the structure and function of plant communities and ecosystems. While it is difficult to extrapolate from instantaneous physiological observations to higher scales, such as whole plant performance or to interactions between plants as components of ecosystems, several key aspects of plant metabolism are scalable. Analyses of stable isotopic composition in plant tissues at natural abundance levels provide a useful tool that can provide insight into the consequences of physiological processes over temporal and spatial scales. Some plant processes continuously fractionate among light and heavy stable isotopic forms of an element; over time this results in integrated measures of plant metabolism. For example, carbon isotope fractionation during photosynthesis results in leaf carbon isotopic composition that is a measure of the set-point for photosynthetic metabolism and of water-use efficiency. Thus it provides information on the temporal scaling of a key physiological process. In contrast, hydrogen is not fractionated during water uptake through the root. Soil water availability in shallow, deep, and/or groundwater layers vary spatially; therefore hydrogen isotope ratios of xylem sap provide a direct measure of the water source currently used by a plant. The longer-term record of carbon and hydrogen isotope ratios is recorded annually in xylem tissues (tree rings). The research in this project addresses variation in stable isotopic composition of aridland plants and its consequences for plant performance and community-level interactions.

  19. Assessment of heavy metal pollution from a Fe-smelting plant in urban river sediments using environmental magnetic and geochemical methods

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Chunxia, E-mail: cxzhang@mail.iggcas.ac.cn [State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, No. 19 Bei Tucheng Xilu, Chaoyang Dist., Beijing 100029 (China); Qiao Qingqing [State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, No. 19 Bei Tucheng Xilu, Chaoyang Dist., Beijing 100029 (China); Piper, John D.A. [Geomagnetism Laboratory, Department of Earth and Ocean Science, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Huang, Baochun [State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, No. 19 Bei Tucheng Xilu, Chaoyang Dist., Beijing 100029 (China)

    2011-10-15

    Environmental magnetic proxies provide a rapid means of assessing the degree of industrial heavy metal pollution in soils and sediments. To test the efficiency of magnetic methods for detecting contaminates from a Fe-smelting plant in Loudi City, Hunan Province (China) we investigated river sediments from Lianshui River. Both magnetic and non-magnetic (microscopic, chemical and statistical) methods were used to characterize these sediments. Anthropogenic heavy metals coexist with coarse-grained magnetic spherules. It can be demonstrated that the Pollution Load Index of industrial heavy metals (Fe, V, Cr, Mo, Zn, Pb, Cd, Cu) and the logarithm of saturation isothermal remanent magnetization, a proxy for magnetic concentration, are significantly correlated. The distribution heavy metal pollution in the Lianshui River is controlled by surface water transport and deposition. Our findings demonstrate that magnetic methods have a useful and practical application for detecting and mapping pollution in and around modern industrial cities. - Highlights: > Assessment of heavy metal (HM) pollution in river sediment using magnetic and chemical methods. > HMs from an Fe-smelting plant coexist with coarse-grained magnetic spherules. > A linear correlation between the Pollution Load Index (PLI) of industrial HMs and a magnetic concentration parameter is demonstrated. > The distribution of HM pollution in river sediments is controlled by surface water flow and deposition. - Heavy metal (HM) contamination of river sediments from industrial input by surface water transport and deposition can be detected by using magnetic methods providing a convenient assessment of HM pollution in industrialized cities.

  20. Heavy metal toxicity in rice and soybean plants cultivated in contaminated soil

    Directory of Open Access Journals (Sweden)

    Maria Lígia de Souza Silva

    2014-04-01

    Full Text Available Heavy metals can accumulate in soil and cause phytotoxicity in plants with some specific symptoms. The present study evaluated the specific symptoms on rice and soybeans plants caused by excess of heavy metals in soil. Rice and soybean were grown in pots containing soil with different levels of heavy metals. A completely randomized design was used, with four replications, using two crop species and seven sample soils with different contamination levels. Rice and soybean exhibited different responses to the high concentrations of heavy metals in the soil. Rice plants accumulated higher Cu, Mn, Pb and Zn concentrations and were more sensitive to high concentrations of these elements in the soil, absorbing them more easily compared to the soybean plants. However, high available Zn concentrations in the soil caused phytotoxicity symptoms in rice and soybean, mainly chlorosis and inhibited plant growth. Further, high Zn concentrations in the soil reduced the Fe concentration in the shoots of soybean and rice plants to levels considered deficient.

  1. Investigation and Evaluation of Heavy Metals Pollution of Agricultural Soils Near a Steel Plant

    Directory of Open Access Journals (Sweden)

    XIE Tuan-hui

    2018-02-01

    Full Text Available The pollution of heavy metals in farmland around a steel plant in the west of Fujian Province was investigated. The pollution index method, principal component analysis and factor analysis on the pollution of Cr, Pb, Cd, Ni, Cu, Zn and As in the soils were carried out to clarify the pollution status, the main source, the degree, and the distribution of the heavy metals pollution in the soil. The secondary standards for acidic agricultural soils of "soil environmental quality standard"(GB 15618-1995were used as the evaluation criterion. The single factor evaluation results showed that the pollution of soil by Cd and Zn in the investigated area was widespread and serious and the points over standard rate was 100% and 95.5% respectively, while the pollution by Pb, Cu and As was slight and the points over standard rate was 29.6%,15.9% and 6.8% respectively. The soils were not polluted by Cr and Ni. The principal component analysis and factor analysis showed that the correlation between Pb, Cd, Cu, Zn and As was significant and homologous. Therefore, the pollution of Pb, Cd, Cu, Zn and As of the soils should be mainly attributed to the pollutants emitted from the steel plant. The correlation between Cr and Ni was also significant and homologous. It was deduced that Cr and Ni in the soils were largely originated from the soils themselves. The comprehensive pollution degree of the heavy metals in the soils decreased as the distance between the steel plant and farmland increasing. The soils of the fields near the entrance of irrigation water from the waste water of the steel plant were more seriously polluted.

  2. Inservice inspection of heavy water plants - a tool in assessing damage to components and life extension

    International Nuclear Information System (INIS)

    Subramanian, C.V.; Thavasimuthu, M.; Bhattacharys, D.K.; Baldev Raj

    1994-01-01

    Any system and its components are expected to give trouble free service over a certain period of time known as life time. The life time is estimated during the design stage. To achieve the design life, certain level of quality are to be defined and this quality has to be worked into the components by proper fabrication processes and their compliance with quality are to be checked. In addition, one has to guard against initiation or propagation of defects which may occur due to normal and abnormal service conditions. Non-destructive test (NDT) techniques are widely used for finding the health of the component. The role of NDT extends from the production stage to the entire life period of the system. This paper highlights the periodic in-service inspection (ISI) carried out on various components of the Heavy Water Plants (HWP) in India in assessing the integrity of the components and predicting the life of the components. (author). 3 refs., 4 figs

  3. Failure analysis of the stud bolt of a canned motor pump of heavy water plant, Talcher

    International Nuclear Information System (INIS)

    Kumar, Sunil; Sethumadhavan, V.; Sah, D.N.; Sivaramakrishnan, K.S.; Kain, Vivekanand; Gadiyar, H.S.

    1990-01-01

    Detailed investigations have been carried out on the failed stud bolts (made of DIN 1.4021 X 20Cr 13) of a canned motor pump of Heavy Water Plant, Talcher, using metallographic, microhardness testing, scanning electron microscopy and electron probe micro-analysis(EPMA) techniques. The studs had failed in a brittle manner in the mid-length portion. The origin of the fracture has been identified to be a corroded region on the stud surface. Branching cracks propagating through silicon rich inclusions have been noted. Two types of inclusions, one containing Mn and S and other containing S, Mn and O 2 have been found in the material. Clusters of large and small inclusions of the above types have been found near the origin of the fracture. It has been concluded that the fracture was caused by corrosion fatigue, initiating at the cluster of inclusions present on the surface of the stud bolts. (author). 7 refs., 5 figs

  4. Characterization and application of dried plants to remove heavy metals, nitrate, and phosphate ions from industrial wastewaters

    Energy Technology Data Exchange (ETDEWEB)

    Chiban, Mohamed; Soudani, Amina; Sinan, Fouad [Department of Chemistry, Faculty of Sciences, Agadir (Morocco); Tahrouch, Saida [Department of Biology, Faculty of Sciences, Agadir (Morocco); Persin, Michel [European Membrane Institute, CRNS, Montpellier (France)

    2011-04-15

    Low cost adsorbents were prepared from dried plants for the removal of heavy metals, nitrate, and phosphate ions from industrial wastewaters. The efficiency of these adsorbents was investigated using batch adsorption technique at room temperature. The dried plant particles were characterized by N{sub 2} at 77 K adsorption, scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and phytochemical screening. The adsorption experiments showed that the microparticles of the dried plants presented a good adsorption of heavy metals, phosphate, and nitrate ions from real wastewaters. This adsorption increased with increasing contact time. The equilibrium time was found to be 30 min for heavy metals and nitrate ions and 240 min for phosphate ions. After the adsorption process, the Pb(II) concentrations, as well as those of Cd(II), Cu(II), and Zn(II) were below the European drinking water norms concentrations. The percentage removal of heavy metals, nitrates, and phosphates from industrial wastewaters by dried plants was {proportional_to}94% for Cd{sup 2+}, {proportional_to}92% for Cu{sup 2+}, {proportional_to}99% for Pb{sup 2+}, {proportional_to}97% for Zn{sup 2+}, {proportional_to}100% for NO{sub 3}{sup -} and {proportional_to}77% for PO{sub 4}{sup 3-} ions. It is proved that dried plants can be one alternative source for low cost absorbents to remove heavy metals, nitrate, and phosphate ions from municipal and industrial wastewaters. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Traversing the Links between Heavy Metal Stress and Plant Signaling

    Science.gov (United States)

    Jalmi, Siddhi K.; Bhagat, Prakash K.; Verma, Deepanjali; Noryang, Stanzin; Tayyeba, Sumaira; Singh, Kirti; Sharma, Deepika; Sinha, Alok K.

    2018-01-01

    Plants confront multifarious environmental stresses widely divided into abiotic and biotic stresses, of which heavy metal stress represents one of the most damaging abiotic stresses. Heavy metals cause toxicity by targeting crucial molecules and vital processes in the plant cell. One of the approaches by which heavy metals act in plants is by over production of reactive oxygen species (ROS) either directly or indirectly. Plants act against such overdose of metal in the environment by boosting the defense responses like metal chelation, sequestration into vacuole, regulation of metal intake by transporters, and intensification of antioxidative mechanisms. This response shown by plants is the result of intricate signaling networks functioning in the cell in order to transmit the extracellular stimuli into an intracellular response. The crucial signaling components involved are calcium signaling, hormone signaling, and mitogen activated protein kinase (MAPK) signaling that are discussed in this review. Apart from signaling components other regulators like microRNAs and transcription factors also have a major contribution in regulating heavy metal stress. This review demonstrates the key role of MAPKs in synchronously controlling the other signaling components and regulators in metal stress. Further, attempts have been made to focus on metal transporters and chelators that are regulated by MAPK signaling. PMID:29459874

  6. Determination of isotopic purity in heavy water to suit process requirement (Preprint No. CA-15)

    Energy Technology Data Exchange (ETDEWEB)

    Kanthiah, W S.A.; Srinivasan, K; Usuf Ali, M C.M. [Heavy Water Plant, Tuticorin (India)

    1989-04-01

    In hydrogen/ammonia based heavy water plants, a simple specific gravity determination of heavy water without any purification or thermostating has proved to be simple and easy. The accuracy is found to be well within +- 0.5% in the isotopic purity (I.P) range of 30 to 90% W/W. There are three main methods that can be adopted for determination of I.P in this range: (1)refractometry, (2) infrared spectrophotometry, and (3) pycnometry. Refractrometry requires thermostating and the practical accuracy attainable is +- 1.5% W/W. Infrared spectrophotometer has a reported accuracy/ precision of +- 0.4%. Pycnometric analysis is simple and requires much less expertise and most suited for plant analyses. An accuracy better than +- 0.5% is attained without giving any correction for buoyancy, weighing to accuracy +- 0.1 mg, measuring temperature +- 0.2degC and sample having pH upto 3. (author). 8 annexures.

  7. Selection of the process for the heavy water production using isotopic exchange amonia-hydrogen

    International Nuclear Information System (INIS)

    Guzman R, G.H.

    1980-01-01

    The utilization of the Petroleos Mexicanos ammonia plants for heavy water production by the isotopic exchange NH 3 -H 2 process is presented, in addition a description of the other heavy water production processes was presented. In the ammonia hydrogen process exist two possible alternatives for the operation of the system, one of them is to carry out the enrichment to the same temperature, the second consists in making the enrichment at two different temperatures (dual temperature process), an analysis was made to select the best alternative. The conclusion was that the best operation is the dual temperature process, which presents higher advantages according to the thermodynamics and engineering of the process. (author)

  8. Heavy metal leaching from mine tailings as affected by plants

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, D.; Schwab, A.P.; Banks, M.K.

    1999-12-01

    A column experiment was conducted to determine the impact of soil cover and plants on heavy metal leaching from mine tailings and heavy metal contaminated soil. Columns made of PVC were constructed with 30 cm subsoil covered by 30 cm of mine tailings followed by 0, 30, or 60 cm subsoil covered by 30 cm of mine tailings followed by 0, 30, or 60 cm of clean topsoil. Two grasses, tall fescue (Festuca arundinacea Schreb.) and big bluestem (Andropogon gerardii), were grown in the columns. The columns were leached at a slow rate for 1 yr with a 0.001 M CaCl{sub 2} solution under unsaturated conditions. The presence of both tall fescue and big bluestem increased Zn and Cd concentrations in the leachate. Lead concentrations in leachates were not affected by the presence of plants. Although plants generally reduced the total amount of water leached, total mass of Zn and Cd leached generally was not impacted by plants. Total mass of Pb leached was positively correlated with total leachate collected from each column. Covering the mine tailings with 60 cm of topsoil increased the mass of Zn and Cd leached relative to no topsoil. When the subsoil was absent, Zn and Cd leaching increased by as much as 20-fold, verifying the ability of soil to act as a sink for metals. Mine tailing remediation by establishing vegetation can reduce Pb movement but may enhance short-term Cd and Zn leaching. However, the changes were relatively small and do not outweigh the benefits of using vegetation in mine tailings reclamation.

  9. Method and equipment to extract and recover tritium from light and heavy water

    International Nuclear Information System (INIS)

    Butler, J.P.; Hammerli, M.M.

    1979-01-01

    A combined electrolysis-catalysis exchange process is proposed to extract tritium, with the aim of being able to reduce the tritium value in the heavy water moderation and cooling system of nuclear power plants. The tritium-contained water is brought into contact in a catalyst column in countercurrent with electrolytically produced hydrogen in this process, the hydrogen is then fed to a catalyst-containing separation column whilst the tritium-contained water flows to the electrolysis cell which produces the hydrogen gas. The process is described in detail. (UWI) [de

  10. Alternate applications of heavy water in biological and technological fields

    International Nuclear Information System (INIS)

    Bhaskaran, M.; Prakash, R.

    2005-01-01

    Deuterium and its various compounds like heavy water exhibit distinctly different properties when compared to hydrogen and its compounds. The differences in properties are due to the primary and secondary isotopic effects. Though heavy water has been used solely for nuclear applications so far, its applications in life sciences and high technology areas are fast emerging. Heavy Water Board has taken up development of alternate applications of heavy water. The study taken up has indicated superior thermal stability for oral polio vaccine prepared in heavy water. This study has revealed various opportunities for application of heavy water or deuterium in life sciences and the paper dwells on these possibilities. The higher stability of compounds with deuterium has also brought in its applications in various high technology areas. These are mainly in micro electronics. Use of deuterium in manufacture of high quality optical fibres has already been established. These are also included in the paper. (author)

  11. Characterization and treatment options for high TOC heavy water

    International Nuclear Information System (INIS)

    Evans, D.; Leilabadi, A.; Rudolph, A.; Williams, D.

    2007-01-01

    High total organic carbon (TOC) and high conductivity contamination in heavy water feed present serious problems for the operation of heavy water upgrader facilities. The authors describe the chemical analysis of a particular batch of contaminated heavy water which had resisted standard clean-up procedures. After chemical characterization, a special clean-up plan was developed and successfully tested in the laboratory, followed by its implementation at site. (author)

  12. Parametric studies to establish natural circulation in advanced heavy water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Bhatia, S K; Dhawan, M L [Reactor Engineering Division, Bhabha Atomic Research Centre, Mumbai (India)

    1994-06-01

    Design of Advanced Heavy Water Reactor (AHWR) is in progress. It consists of vertical pressure tubes with boiling light water coolant flowing through the tubes and heavy water moderator in the calandria. In PHWRs, core heat removal is through forced circulation of the coolant by PHT pumps. In AHWR, no PHT pumps are used and core heat is carried away by natural circulation of the coolant due to density difference between steam/water mixture inside the core and the water region outside the core. This passive means of core heat removal results in a number of benefits viz. (a) extra length of piping, valves, instruments, power supply and control systems for functioning of instruments are eliminated, (b) plant layout is simplified, (c) maintenance of valves and instruments is reduced. Natural circulation in AHWR is achieved by keeping the steam drum at a sufficient height above the core to get the required driving force. The loop height depends on many factors i.e. channel power, V{sub c}/V{sub f} ratio (ratio of coolant volume to fuel volume) and core height. The effect of these parameters on the loop height to establish natural circulation have been studied and presented. (author). 1 ref., 1 fig., 1 tab.

  13. Generic safety issues for nuclear power plants with pressurized heavy water reactors and measures for their resolution

    International Nuclear Information System (INIS)

    2007-06-01

    be used in reassessing the safety of individual operating plants. In 1998, the IAEA completed IAEA-TECDOC-1044 entitled Generic Safety Issues for Nuclear Power Plants with Light Water Reactors and Measures Taken for their Resolution and established the associated LWRGSIDB database (Computer Manual Series No. 13). The present compilation, which is based on broad international experience, is an extension of this work to cover pressurized heavy water reactors (PHWRs). As in the case of LWRs, it is one element in the framework of IAEA activities to assist Member States in reassessing the safety of operating nuclear power plants. It addresses generic safety issues identified in nuclear power plants using PHWRs. In most cases, the measures taken or planned to resolve these issues are also identified. The work on this report was initiated by the Senior Regulators of Countries Operating CANDU-Type Nuclear Power Plants at one of their annual meetings. It was carried out within the framework of the IAEA's programme on National Regulatory Infrastructure for Nuclear Installation Safety and serves to enhance regulatory effectiveness through the exchange of safety related information

  14. Thermal conductivity coefficients of water and heavy water in the liquid state up to 3700C

    International Nuclear Information System (INIS)

    Le Neindre, B.; Bury, P.; Tufeu, R.; Vodar, B.

    1976-01-01

    The thermal conductivity coefficients of water and heavy water of 99.75 percent isotopic purity were measured using a coaxial cylinder apparatus, covering room temperature to their critical temperatures, and pressures from 1 to 500 bar for water, and from 1 to 1000 bar for heavy water. Following the behavior of the thermal conductivity coefficient of water, which shows a maximum close to 135 0 C, the thermal conductivity coefficient of heavy water exhibits a maximum near 95 0 C and near saturation pressures. This maximum is displaced to higher temperatures when the pressure is increased. Under the same temperature and pressure conditions the thermal conductivity coefficient of heavy water was lower than for water. The pressure effect was similar for water and heavy water. In the temperature range of our experiments, isotherms of thermal conductivity coefficients were almost linear functions of density

  15. Survival of tumor-bearing mice exposed to heavy water or heavy water plus methotrexate

    International Nuclear Information System (INIS)

    Laissue, J.A.; Buerki, H.; Berchtold, W.

    1982-01-01

    Moderate body deuteration combined with a cytostatic drug [methotrexate (MTX)] significantly increases the survival time of young adult DBA/2 mice bearing transplantable P815. L5178Y, or L1210 tumors. Neoplastic cells were grown in vitro from tumor stock and injected i.p. into mice from two groups, one drinking tap water, and other drinking 30% heavy water in tap water. One-half of the animals in each of these two groups was given a single injection of MTX (4 mg/kg body weight) on 3 consecutive days per week. At death, extension of primary and metastatic tumors was examined and was found to be macro- and microscopically comparable in the corresponding groups. The mean survival time of untreated mice drinking tap water was about 2 weeks following injection of the fast-growing P815, L5178Y, or L1210 (V) tumors and approximately 5 weeks after injection of cells from a slower-growing L1210 subline. Body deuteration alone roughly doubled the survival time solely of mice bearing this L1210 subline. Treatment with MTX approximately doubled the mean survival time of hosts bearing one of the fast-growing tumors. Combined treatment with heavy water and MTX increased the mean survival time of the mice in all groups by 15 to 125% as compared to control values. The reasons for this effect are unknown. However, heavy water has been shown to exert antimitotic activity and to depress the incorporation of radioactive precursors into DNA of proliferating mammalian cells. The depression of antibody formation following antigenic stimulation and the reduction in numbers of nonneoplastic lymphoid cells of mice following moderate body deuteration may have contributed to the enhancement of MTX activity in addition to other effects of deuterium

  16. Competitive sorption of heavy metals by water hyacinth roots.

    Science.gov (United States)

    Zheng, Jia-Chuan; Liu, Hou-Qi; Feng, Hui-Min; Li, Wen-Wei; Lam, Michael Hon-Wah; Lam, Paul Kwan-Sing; Yu, Han-Qing

    2016-12-01

    Heavy metal pollution is a global issue severely constraining aquaculture practices, not only deteriorating the aquatic environment but also threatening the aquaculture production. One promising solution is adopting aquaponics systems where a synergy can be established between aquaculture and aquatic plants for metal sorption, but the interactions of multiple metals in such aquatic plants are poorly understood. In this study, we investigated the absorption behaviors of Cu(II) and Cd(II) in water by water hyacinth roots in both single- and binary-metal systems. Cu(II) and Cd(II) were individually removed by water hyacinth roots at high efficiency, accompanied with release of protons and cations such as Ca 2+ and Mg 2+ . However, in a binary-metal arrangement, the Cd(II) sorption was significantly inhibited by Cu(II), and the higher sorption affinity of Cu(II) accounted for its competitive sorption advantage. Ionic exchange was identified as a predominant mechanism of the metal sorption by water hyacinth roots, and the amine and oxygen-containing groups are the main binding sites accounting for metal sorption via chelation or coordination. This study highlights the interactive impacts of different metals during their sorption by water hyacinth roots and elucidates the underlying mechanism of metal competitive sorption, which may provide useful implications for optimization of phytoremediation system and development of more sustainable aquaculture industry. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Status of advanced technology and design for water cooled reactors: Heavy water reactors

    International Nuclear Information System (INIS)

    1989-07-01

    In 1987 the IAEA established the International Working Group on Advanced Technologies for Water-Cooled Reactors (IWGATWR). Within the framework of the IWGATWR the IAEA Technical Report on Status of Advanced Technology and Design for Water Cooled Reactors, Part I: Light Water Reactors and Part II: Heavy Water Reactors, has been undertaken to document the major current activities and trends of technological improvement and development for future water reactors. Part I of the report dealing with Light Water Reactors (LWRs) was published in 1988 (IAEA-TECDOC-479). Part II of the report covers Heavy Water Reactors (HWRs) and has now been prepared. This report is based largely upon submissions from Member States. It has been supplemented by material from the presentations at the IAEA Technical Committee and Workshop on Progress in Heavy Water Reactor Design and Technology held in Montreal, Canada, December 6-9, 1988. It is hoped that this part of the report, containing the status of advanced heavy water reactor technology up to 1988 and ongoing development programmes will aid in disseminating information to Member States and in stimulating international cooperation. Refs, figs and tabs

  18. Determination of isotopic purity in heavy water to suit process requirement (Preprint No. CA-15)

    International Nuclear Information System (INIS)

    Kanthiah, W.S.A.; Srinivasan, K.; Usuf Ali, M.C.M.

    1989-04-01

    In hydrogen/ammonia based heavy water plants, a simple specific gravity determination of heavy water without any purification or thermostating has proved to be simple and easy. The accuracy is found to be well within ± 0.5% in the isotopic purity (I.P) range of 30 to 90% W/W. There are three main methods that can be adopted for determination of I.P in this range: (1)refractometry, (2) infrared spectrophotometry, and (3) pycnometry. Refractrometry requires thermostating and the practical accuracy attainable is ± 1.5% W/W. Infrared spectrophotometer has a reported accuracy/ precision of ± 0.4%. Pycnometric analysis is simple and requires much less expertise and most suited for plant analyses. An accuracy better than ± 0.5% is attained without giving any correction for buoyancy, weighing to accuracy ± 0.1 mg, measuring temperature ± 0.2degC and sample having pH upto 3. (author). 8 annexures

  19. assessment of heavy metals concentration in drinking water ...

    African Journals Online (AJOL)

    userpc

    guidelines (WHO 2005). Findings suggest that continues water quality monitoring should be carried out to check the concentration levels of heavy metals in that area, to prevent them from been above the limit of WHO. Keywords: Atomic Absorption Spectrophotometers, Heavy Metals, Water, Kauru Local. Government Area.

  20. Phosphorus-loaded biochar changes soil heavy metals availability and uptake potential of maize (Zea mays L.) plants.

    Science.gov (United States)

    Ahmad, Munir; Usman, Adel R A; Al-Faraj, Abdullah S; Ahmad, Mahtab; Sallam, Abdelazeem; Al-Wabel, Mohammad I

    2018-03-01

    Biochar (BC) was produced by pyrolyzing the date palm leaf waste at 600 °C and then loaded with phosphorus (P) via sorption process. Greenhouse pot experiment was conducted to investigate the application effects of BC and P-loaded biochar (BCP) on growth and availability of P and heavy metals to maize (Zea mays L.) plants grown in contaminated mining soil. The treatments consisted of BC and BCP (at application rates of 5, 10, 20, and 30 g kg -1 of soil), recommended NK and NPK, and a control (no amendment). Sorption experiment showed that Langmuir predicted maximum P sorption capacity of BC was 13.71 mg g -1 . Applying BCP increased the soil available P, while BC and BCP significantly decreased the soil labile heavy metals compared to control. Likewise, heavy metals in exchangeable and reducible fractions were transformed to more stable fraction with BC and BCP applications. The highest application rate of BCP (3%) was most effective treatment in enhancing plant growth parameters (shoot and root lengths and dry matter) and uptake of P and heavy metals by 2-3 folds. However, based on metal uptake and phytoextraction indices, total heavy metals extraction by maize plants was very small for practical application. It could be concluded that using P-loaded biochar as a soil additive may be considered a promising tool to immobilize heavy metals in contaminated mining areas, while positive effects on the biomass growth of plants may assist the stabilization of contaminated areas affected by wind and water erosion. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Assessment of heavy metal pollution from a Fe-smelting plant in urban river sediments using environmental magnetic and geochemical methods

    International Nuclear Information System (INIS)

    Zhang Chunxia; Qiao Qingqing; Piper, John D.A.; Huang, Baochun

    2011-01-01

    Environmental magnetic proxies provide a rapid means of assessing the degree of industrial heavy metal pollution in soils and sediments. To test the efficiency of magnetic methods for detecting contaminates from a Fe-smelting plant in Loudi City, Hunan Province (China) we investigated river sediments from Lianshui River. Both magnetic and non-magnetic (microscopic, chemical and statistical) methods were used to characterize these sediments. Anthropogenic heavy metals coexist with coarse-grained magnetic spherules. It can be demonstrated that the Pollution Load Index of industrial heavy metals (Fe, V, Cr, Mo, Zn, Pb, Cd, Cu) and the logarithm of saturation isothermal remanent magnetization, a proxy for magnetic concentration, are significantly correlated. The distribution heavy metal pollution in the Lianshui River is controlled by surface water transport and deposition. Our findings demonstrate that magnetic methods have a useful and practical application for detecting and mapping pollution in and around modern industrial cities. - Highlights: → Assessment of heavy metal (HM) pollution in river sediment using magnetic and chemical methods. → HMs from an Fe-smelting plant coexist with coarse-grained magnetic spherules. → A linear correlation between the Pollution Load Index (PLI) of industrial HMs and a magnetic concentration parameter is demonstrated. → The distribution of HM pollution in river sediments is controlled by surface water flow and deposition. - Heavy metal (HM) contamination of river sediments from industrial input by surface water transport and deposition can be detected by using magnetic methods providing a convenient assessment of HM pollution in industrialized cities.

  2. Correlation between heavy metal contents and antioxidants in medicinal plants grown in mining areas

    International Nuclear Information System (INIS)

    Maharia, R.; Dutta, R.K.; Acharya, R.; Reddy, A.V.R.

    2010-01-01

    Full texts: Medicinal plants are widely used as alternate therapeutic agents for various diseases. Three medicinal plants grown in copper mining regions of Khetri in Rajasthan was analyzed for heavy metal contents by instrumental neutron activation analysis. The copper levels were found to be two to three folds higher in these plant leaves as compared to the reported copper levels in the medicinal plants grown in environmentally friendly regions. In our previous study on heavy metals in soil and medicinal plant of Khetri region we have shown bioaccumulation of Cu in the medicinal plants. In addition, the levels of Cr, Fe and Zn were also higher. Antioxidant properties of medicinal plants are one of their major therapeutic functionalities. The role of elevated levels of heavy metals in the medicinal plants was studied with respect to their antioxidant properties. Standard procedures were used for measuring total phenols, flavanoids and DPPH assay of these medicinal plants which were correlated with the heavy metals contents of these plants

  3. Factors affecting heavy metal uptake in plant selection for phytoremediation

    Energy Technology Data Exchange (ETDEWEB)

    Anton, A.; Mathe-Gaspar, G. [Research Inst. for Soil Science and Agricultural Chemistry of the Hungarian Academy of Sciences, Budapest (Hungary)

    2005-04-01

    The heavy metal uptake of ten plant species was studied under different soil and climatic conditions. Effects of soil pH, temperature, plant species and phenophase on the heavy metal content of stems and leaves were determined in pot experiments. Plants and soil samples were collected from a lead/zinc mine ore (Gyoengyoesoroszi, Hungary) and characterised by high contents of Pb, Zn, As, Cd, Cu. The possibility of an adapted phytoremediation technology was indicated by different bioconcentration factors (BCF). The BCF depended markedly (10- to 100-fold) on plant species and environmental conditions. Based on our results a ''season-adapted'' phytoextraction technology with different plant species (utilising their different temperature requirements and/or harvest time) is suggested. (orig.)

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

    International Nuclear Information System (INIS)

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

    1989-01-01

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

  5. Minimal watering regime impacts on desert adapted green roof plant performance

    Science.gov (United States)

    Kovachich, S.; Pavao-Zuckerman, M.; Templer, S.; Livingston, M.; Stoltz, R.; Smith, S.

    2011-12-01

    Roof tops can cover one-fifth of urban areas and can greatly alter the movement of matter and energy in cities. With traditional roofing methods and materials, roof tops readily absorb heat and as a result, buildings and the surrounding urban area heat to unnaturally high temperatures. It is hypothesized that extensive green roofs would have wide-ranging benefits for arid environments. However, little is known about the cost of water use associated with green roof installations and how to balance energy reduction needs with water costs in this water limited environment. We are conducting a pilot study to test whether a) green roofs with native plants and environmentally-responsible watering regimes will prove successful in arid environments and if b) green roofs provide ecosystem services with responsible water application. Three species of Sonoran Desert natives, Dyssodia pentachaeta (groundcover), Calliandra eriophylla (shrub), and Hesperaloe parviflora (succulent) have been planted in experimental plots [1 m2 model houses and roofs, replicated in triplicate] with two sandy, rocky desert soil mixtures (light mix: 60% expanded shale and heavy mix: organic and sandy mix with 50% shale) at the Biosphere 2 campus near Oracle, Az. The green roofs are watered by two different techniques. The first technique provides "smart watering", the minimal amount of water needed by green roof plants based on precipitation and historical data. The second watering technique is considered heavy and does not take into account environmental conditions. Preliminary data from the experimental plots shows a 30% decrease in daytime roof top temperatures on green roofs and a 10% decrease in interior temperatures in buildings with green roofs. This trend occurs with both watering regimes (heavy and light). This finding suggests that additional irrigation yields no extra heat reduction and energy savings. In order to explain this phenomenon more clearly, we use co-located temperature and

  6. Good practices in heavy water reactor operation

    International Nuclear Information System (INIS)

    2010-06-01

    The value and importance of organizations in the nuclear industry engaged in the collection and analysis of operating experience and best practices has been clearly identified in various IAEA publications and exercises. Both facility safety and operational efficiency can benefit from such information sharing. Such sharing also benefits organizations engaged in the development of new nuclear power plants, as it provides information to assist in optimizing designs to deliver improved safety and power generation performance. In cooperation with Atomic Energy of Canada, Ltd, the IAEA organized the workshop on best practices in Heavy Water Reactor Operation in Toronto, Canada from 16 to 19 September 2008, to assist interested Member States in sharing best practices and to provide a forum for the exchange of information among participating nuclear professionals. This workshop was organized under Technical Cooperation Project INT/4/141, on Status and Prospects of Development for and Applications of Innovative Reactor Concepts for Developing Countries. The workshop participants were experts actively engaged in various aspects of heavy water reactor operation. Participants presented information on activities and practices deemed by them to be best practices in a particular area for consideration by the workshop participants. Presentations by the participants covered a broad range of operational practices, including regulatory aspects, the reduction of occupational dose, performance improvements, and reducing operating and maintenance costs. This publication summarizes the material presented at the workshop, and includes session summaries prepared by the chair of each session and papers submitted by the presenters

  7. Woody plant willow in function of river water protection

    Directory of Open Access Journals (Sweden)

    Babincev Ljiljana M.

    2011-01-01

    Full Text Available Coastal area surrounding the river Ibar, in the area between cities of Kosovska Mitrovica and Leposavić in the north of Kosovo and Metohija, is occupied with seven industrial waste dumps. These dumps were all part of the exploitation and flotation refinement of raw mineral materials, metallurgic refinement of concentrates, chemical industry, industrial refinement and energetic facilities of Trepča industrial complex. The existing waste dumps, both active and inactive, are of heterogenic chemical composition. Its impact on the river water is shown by the content of heavy metals found in it. Removal of lead, cadmium and zinc would be economically unrewarding, regardless of the technology used. Wooden plant that prevails in this area is white willow. This work is focused on the removal of heavy metals (Pb, Cd and Zn from the water of the river Ibar using white willow. Roots of the willow are cultivated using the method of water cultures in an individual solution of heavy metals and river water sample. The preparation of the samples for analysis was performed by burning the herbal material and dissolving ashes in the appropriate acids. The concentrations of metals were determined by the stripping analysis. In the investigated heavy metal solutions the biomass increase is 25.6% in lead solution, 27.3% in cadmium and 30.7% in zinc solution. The increase of biomass in nutritional solution, without the heavy metals, is 32.4% and in river water sample 27.5%. The coefficient of bioaccumulation in solutions with heavy metals is 1.6% in lead solution, 1.9% in cadmium and 2.2% in zinc solution. Heavy metals accumulation is 18.74 μg of lead, 20.09 μg of cadmium and 22.89 μg of zinc. The coefficient of bioaccumulation of the water samples, that contained 44.83 μg/dm3 of lead, 29.21 μg/dm3 of cadmium and 434.00 μg/dm3 of zinc, during the period of 45 days, was 30.3% for lead, 53.4% for cadmium and 3.9% for zinc. The concentrations of accumulated metals

  8. Biochar-enhanced composts reduce the potential leaching of nutrients and heavy metals and suppress plant-parasitic nematodes in excessively fertilized cucumber soils.

    Science.gov (United States)

    Cao, Yune; Gao, Yanming; Qi, Yanbin; Li, Jianshe

    2018-03-01

    Excessive fertilization is a common agricultural practice that has largely reduced soil nutrient retention capacity and led to nutrient leaching in China. To reduce nutrient leaching, in this study, we evaluated the application of biochar, compost, and biochar-compost on soil properties, leaching water quality, and cucumber plant growth in soils with different nutrient levels. In general, the concentrations of nutrients and heavy metals in leaching water were higher under high-nutrient conditions than under low-nutrient conditions. Both biochar and compost efficiently enhanced soil cation exchange capacity (CEC), water holding capacity (WHC), and microbial biomass carbon (MBC), nitrogen (MBN), and phosphorus (MBP), reduced the potential leaching of nutrients and heavy metals, and improved plant growth. The efficiency of biochar and compost in soil CEC, WHC, MBC, MBN, and MBP and plant growth was enhanced when applied jointly. In addition, biochar and biochar-enhanced compost efficiently suppressed plant-parasitic nematode infestation in a soil with high levels of both N and P. Our results suggest that biochar-enhanced compost can reduce the potential environmental risks in excessively fertilized vegetable soils.

  9. Analysis of Heavy Metals in Water and Fish (Tilapia sp.) Samples from Tasik Mutiara, Puchong

    International Nuclear Information System (INIS)

    Ismaniza Ismail; Idaliza Mat Saleh

    2012-01-01

    The concentrations of seven heavy metals (Al, As, Cd, Cu, Fe, Pb and Zn) were detected in muscle tissues of Tilapia sp. (black tilapia) collected from the lake of Taman Mutiara, Puchong. Samples were collected for several months in the end of 2009 at three sampling points. Heavy metals in fish and water samples were analyzed by Inductively Coupled Plasma - Optical Emission Spectroscopy (ICP-OES). Only Al, Cu, Fe and Zn were detected in the order Fe > Zn > Al > Cu, whereas concentrations of As, Cd and Pb were below the detection limit. The concentrations of heavy metals in water samples were low and below the detection limit. The levels of heavy metals in the fish samples can be considered as a serious matter of concern as it may be consumed and it signifies the degradation of lake quality. Generally, the sources of heavy metals in the Tasik Mutiara, Puchong could be attributed to the illegal waste dumping activity and discharge from the nearby sewage treatment plant into the lake which promote eutrophication in the lake. It could also be attributed to the Low Dissolved Oxygen (DO) levels in the lake. (author)

  10. Operation management of the prototype heavy water reactor 'Fugen'

    International Nuclear Information System (INIS)

    Muramatsu, Akira; Takei, Hiroaki; Iwanaga, Shigeru; Noda, Masao; Hara, Hidemi

    1983-01-01

    The advanced thermal reactor Fugen power station has continued almost smooth operation since it began the full scale operation as the first homemade power reactor in Japan in March, 1979. In the initial period of operation, some troubles were experienced, but now, it can be said that the operational techniques of heavy water-moderated, boiling light water-cooled, pressure tube type reactors have been established, through the improvement of the operational method and equipment, and the operational experience. Also, the verification of the operational ability, maintainability, reliability and safety of this new type reactor, that is the mission of the prototype reactor, achieved steadily the good results. Hereafter, the verification of operational performance is the main objective because it is required for the design, construction and operation of the demonstration reactor. The organization for the operation management and operation, the communication at the time of the abnormality, the operation of the plant, that is, start up, stop and the operation at the rated output, the works during plant stoppage, the operation at the time of the plant abnormality, the operation of waste treatment facility and others, the improvement of the operational method, and the education and training of operators are reported. (Kako, I.)

  11. Heavy metal displacement in chelate-irrigated soil during phytoremediation

    Science.gov (United States)

    Madrid, F.; Liphadzi, M. S.; Kirkham, M. B.

    2003-03-01

    Heavy metals in wastewater sewage sludge (biosolids), applied to land, contaminate soils. Phytoremediation, the use of plants to clean up toxic heavy metals, might remove them. Chelating agents are added to soil to solubilize the metals for enhanced phytoextraction. Yet no studies follow the displacement and leaching of heavy metals in soil with and without roots following solubilization with chelates. The objective of this work was to determine the mobility of heavy metals in biosolids applied to the surface of soil columns (76 cm long; 17 cm diam.) with or without plants (barley; Hordeum vulgare L.). Three weeks after barley was planted, all columns were irrigated with the disodium salt of the chelating agent, EDTA (ethylenediamine tetraacetic acid) (0.5 g/kg soil). Drainage water, soil, and plants were analyzed for heavy metals (Cd, Cu, Fe, Mn, Ni, Pb, Zn). Total concentrations of the heavy metals in all columns at the end of the experiment generally were lower in the top 30 cm of soil with EDTA than without EDTA. The chelate increased concentrations of heavy metals in shoots. With or without plants, the EDTA mobilized Cd, Fe, Mn, Ni, Pb, and Zn, which leached to drainage water. Drainage water from columns without EDTA had concentrations of these heavy metals below detection limits. Only Cu did not leach in the presence of EDTA. Even though roots retarded the movement of Cd, Fe, Mn, Ni, Pb, and Zn through the EDTA-treated soil from 1 d (Cd) to 5 d (Fe), the drainage water from columns with EDTA had concentrations of Cd, Fe, Mn, and Pb that exceeded drinking water standards by 1.3, 500, 620, and 8.6 times, respectively. Because the chelate rendered Cd, Fe, Mn, Ni, Pb, and Zn mobile, it is suggested that the theory for leaching of soluble salts, put forward by Nielsen and associates in 1965, could be applied to control movement of the heavy metals for maximum uptake during chelate-assisted phytoremediation.

  12. Heavy water isotopic rectification in the ''ORPHEE'' reactor. SACLAY studies Centre

    International Nuclear Information System (INIS)

    Lejeune, P.; Breant, P.

    1993-01-01

    ORPHEE reactor supplies neutron beams, which are got back in a heavy water reflector. The neutron beams intensity depends on the reflector quality which is determined by the isotopic content of the heavy water. The deuterium submitted to core irradiation changes in radioactive tritium which must be eliminated largely for reasons of safety. The column must keep the heavy water isotopic content of the reflector to a value higher than 99.8% by eliminating light water by fractional distillation or rectification. This column is also used for the tritium elimination of heavy water. 13 figs

  13. Critical heat flux experiments in a circular tube with heavy water and light water. (AWBA Development Program)

    International Nuclear Information System (INIS)

    Williams, C.L.; Beus, S.G.

    1980-05-01

    Experiments were performed to establish the critical heat flux (CHF) characteristics of heavy water and light water. Testing was performed with the up-flow of heavy and of light water within a 0.3744 inch inside diameter circular tube with 72.3 inches of heated length. Comparisons were made between heavy water and light water critical heat flux levels for the same local equilibrium quality at CHF, operating pressure, and nominal mass velocity. Results showed that heavy water CHF values were, on the average, 8 percent below the light water CHF values

  14. classification of plants according to their heavy metal content around

    African Journals Online (AJOL)

    Mgina

    accumulated heavy metals around North Mara Gold Mine were not known. To study such ... heavy metal hyperaccumulator plants for possible future remediation of the study area. ... mine is about 100 kilometers east of Lake. Victoria and 20 ...

  15. Feasibility analysis of EDXRF method to detect heavy metal pollution in ecological environment

    Science.gov (United States)

    Hao, Zhixu; Qin, Xulei

    2018-02-01

    The change of heavy metal content in water environment, soil and plant can reflect the change of heavy metal pollution in ecological environment, and it is important to monitor the trend of heavy metal pollution in eco-environment by using water environment, soil and heavy metal content in plant. However, the content of heavy metals in nature is very low, the background elements of water environment, soil and plant samples are complex, and there are many interfering factors in the EDXRF system that will affect the spectral analysis results and reduce the detection accuracy. Through the contrastive analysis of several heavy metal elements detection methods, it is concluded that the EDXRF method is superior to other chemical methods in testing accuracy and method feasibility when the heavy metal pollution in soil is tested in ecological environment.

  16. Heavy Metal Polluted Soils: Effect on Plants and Bioremediation Methods

    OpenAIRE

    Chibuike, G. U.; Obiora, S. C.

    2014-01-01

    Soils polluted with heavy metals have become common across the globe due to increase in geologic and anthropogenic activities. Plants growing on these soils show a reduction in growth, performance, and yield. Bioremediation is an effective method of treating heavy metal polluted soils. It is a widely accepted method that is mostly carried out in situ; hence it is suitable for the establishment/reestablishment of crops on treated soils. Microorganisms and plants employ different mechanisms for...

  17. Method and apparatus for enrichment or upgrading heavy water

    International Nuclear Information System (INIS)

    Butler, J.P.; Hammerli, M.

    1979-01-01

    A method and apparatus for upgrading and final enrichment of heavy water are described, comprising means for contacting partially enriched heavy water feed in a catalyst column with hydrogen gas (essentially D 2 ) originating in an electrolysis cell so as to enrich the feed water with deuterium extracted from the electrolytic hydrogen gas and means for passing the deuterium enriched water to the electrolysis cell. (author)

  18. Correlation of Heavy Element in Sea Water and Sediment Samples from Peninsula of Muria

    International Nuclear Information System (INIS)

    Rosidi; Sukirno

    2007-01-01

    The analysis of heavy metals in marine environmental samples peninsula of Muria in the year 2004 has been carried out by using neutron activation analysis (NAA) method. The objective of this analysis is to know the distribution of heavy metals in the sea water and sediment, which accommodate the recent environmental data in supporting the license of site for the nuclear power plants (NPP). The result of the analysis show that there were only 5 observed elements found in sea water and sediment were Cd, Co, Cr, Sb and Sc. All of heavy metals from sea water (0.002 mg/l) are obviously lower than the threshold value established by environmental minister Act; Kep LH No 51/2004. From the observed data to use software of SPSS version 10, application of the Pearson correlation (r) shows that between Co with Sc was indicator show a highly positive significant correlation (r=0.928), between Cr with Sc was sufficiently positive high (r=0.756), between Cr with Cd was precisely (r=0.611) while Co with Sb shows the significantly low (r=0.429). (author)

  19. The Canadian heavy water situation

    International Nuclear Information System (INIS)

    Dahlinger, A.

    The Canadian heavy water industry is analyzed. Supply and demand are predicted through 1985. Pricing is broken down into components. Backup R and D contributes greatly to process improvements. (E.C.B.)

  20. Tritium separation from heavy water using electrolysis

    International Nuclear Information System (INIS)

    Ogata, Y.; Sakuma, Y.; Ohtani, N.; Kodaka, M.

    2001-01-01

    A tritium separation from heavy water by the electrolysis using a solid polymer electrode (SPE) was specified on investigation. The heavy water (∼10 Bq g -1 ) and the light water (∼70 Bq g -1 ) were electrolysed using an electrolysis device (Tripure XZ001, Permelec Electrode Ltd.) with the SPE layer. The cathode was made of stainless steel (SUS314). The electrolysis was carried out at 20 A x 60 min, with the electrolysis temperature at 10, 20, or 30degC, and 15 A x 80 min at 5degC. The produced hydrogen and oxygen gases were recombined using a palladium catalyst (ND-101, N.E. Chemcat Ltd.) with nitrogen gas as a carrier. The activities of the water in the cell and of the recombined water were analyzed using a liquid scintillation counter. The electrolysis potential to keep the current 20 A was 2-3 V. The yields of the recombined water were more than 90%. The apparent separation factors (SF) for the heavy water and the light water were ∼2 and ∼12, respectively. The SF value was in agreement with the results in other work. The factors were changed with the cell temperature. The electrolysis using the SPE is applicable for the tritium separation, and is able to perform the small-scale apparatus at the room temperature. (author)

  1. The correlation of metal content in medicinal plants and their water extracts

    Directory of Open Access Journals (Sweden)

    Ranđelović Saša S.

    2013-01-01

    Full Text Available The quality of some medicinal plants and their water extracts from South East Serbia is determined on the basis of metal content using atomic absorption spectrometry. The two methods were used for the preparation of water extracts, to examine the impact of the preparation on the content of metals in them. Content of investigated metals in both water extracts is markedly lower then in medicinal plants, but were higher in water extract prepared by method (I, with exception of lead content. The coefficients of extraction for the observed metal can be represented in the following order: Zn > Mn > Pb > Cu > Fe. Correlation coefficients between the metal concentration in the extract and total metal content in plant material vary in the range from 0.6369 to 0.9956. This indicates need the plants to be collected and grown in the unpolluted area and to examine the metal content. The content of heavy metals in the investigated medicinal plants and their water extracts is below the maximum allowable values, so they are safe to use.

  2. High resolution conductometry for isotopic assay of deuterium in mixtures of heavy water and light water

    International Nuclear Information System (INIS)

    Ananthanarayanan, R.; Sahoo, P.; Murali, N.

    2014-01-01

    A PC based high resolution conductivity monitoring technique has been deployed for determination of isotopic purity of heavy water in samples containing heavy water and light water mixtures using pulsating sensor based conductivity monitoring instrument. The technique involves accurate determination of conductivities of a series of specially treated heavy water and light water mixtures of various compositions at a constant solution temperature. The shift in conductivity (Δκ), which is the difference between conductivities of composite mixture after and before the formation of a typical complex compound (boric acid–mannitol complex in this case), shows a smooth and reproducible decreasing trend with increase in percentage composition of heavy water. This relation, which is obtained by appropriate calibration, is used in the software program for direct display of isotopic purity of heavy water. The technique is examined for determination of percentage composition of heavy water in the entire range of concentration (0-100 %) with reasonable precision (relative standard deviation, RSD ≤1.5 %). About 1 mL of sample is required for each analysis and analysis is completed within a couple of minutes after pretreatment of sample. The accuracy in measurement is ≤1.75 %. (author)

  3. Water use, productivity and interactions among desert plants. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Ehleringer, J.R.

    1992-11-17

    Productivity, stability, and competitive interactions among ecosystem components within aridlands are key processes related directly to water in deserts. This project assumes that integrated aspects of plant metabolism provide insight into the structure and function of plant communities and ecosystems. While it is difficult to extrapolate from instantaneous physiological observations to higher scales, such as whole plant performance or to the interactions between plants as components of ecosystems, several key aspects of plant metabolism are scalable. Analyses of stable isotopic composition in plant tissues at natural abundance levels provide a useful tool that can provide insight into the consequences of physiological processes over temporal and spatial scales. Some plant processes continuously fractionate among light and heavy stable isotopic forms of an element; over time this results in integrated measures of plant metabolism. For example, carbon isotope fractionation during photosynthesis results in leaf carbon isotopic composition that is a measure of the set-point for photosynthetic metabolism and of water-use efficiency. Thus it provides information on the temporal scaling of a key physiological process.

  4. Cell growth and protein synthesis of unicellular green alga Chlamydomonas in heavy water

    International Nuclear Information System (INIS)

    Ishida, M.R.

    1983-01-01

    The effects of heavy water on the cell growth and protein synthesis of the photoautotrophically growing Chlamydomonas cells were studied. The growth rate of the cells is inversely proportional to the concentrations of heavy water. The cells can barely live in 90% heavy water, but they die in 99.85% heavy water within a few days. Incorporation of 14 Cleucine into cells is markedly stimulated by heavy water of various concentrations between 30 and 99.85% in the case of the short time incubation. Contrary to this, in the long time incubation as several days, heavy water inhibits the protein synthesis. Such two modes of the protein synthetic activities are dependent upon the incubation time of the cells grown photoautotrophically in the heavy water media. (author)

  5. High converter pressurized water reactor with heavy water as a coolant

    International Nuclear Information System (INIS)

    Ronen, Y.; Reyev, D.

    1983-01-01

    There is an increasing interest in water breeder and high converter reactors. The increase in the conversion ratio of these reactors is obtained by hardening the neutron spectrum achieved by tightening the reactor's lattice. Another way of hardening the neutron spectrum is to replace the light water with heavy water. Two pressurized water reactor fuel cycles that use heavy water as a coolant are considered. The first fuel cycle is based on plutonium and depleted uranium, and the second cycle is based on plutonium and enriched uranium. The uranium ore and separative work unit (SWU) requirements are calculated as well as the fuel cycle cost. The savings in uranium ore are about40 and 60% and about40% in SWU for both fuel cycles considered

  6. Preliminary assessment of heavy metals in water, sediment and macrophyte ( Lemna minor) collected from Anchar Lake, Kashmir, India

    Science.gov (United States)

    Showqi, Irfana; Lone, Farooq Ahmad; Naikoo, Mehrajuddin

    2018-06-01

    Water samples, sediments and free floating macrophytic plant, Lemna minor specimens were collected from five designated sites in Anchar lake (Srinagar, J&K, India) to assess its heavy metal (Cu, Cr, Zn, Ni, Cd, Pb) load and changes on seasonal basis. The concentration of heavy metals was determined using atomic absorption spectroscopy. Most of the samples were found within limits of maximum permissible concentrations as recommended by WHO (Guidelines for drinking water quality, pp 491-493, 2006). During all the seasons, highest concentration of all heavy metals (Cu, Cr, Zn, Ni, Cd, Pb) was recorded at highly polluted sites of the lake viz. near agricultural fields (S1), near settlements (S3) and SKIMS (S4). These sites received huge agrochemical run-off from the surrounding agricultural fields, solid and liquid wastes from the nearby catchment areas and effluents from Sher-e-Kashmir Institute of Medical Sciences (SKIMS) compared to control site lake centre (S5). Furthermore, most of the metals in water and sediment were found with highest concentration during autumn (Viz., Cu-1.5 ppm; Zn-0.38 ppm; Ni-1.89 ppm; Pb-0.84 ppm in water and Cu-26.9 ppm; Zn-13.6 ppm; Pb-4.33 ppm in sediment) and summer (Viz., Cr-0.68 ppm in water and Ni-4.8 ppm; Cd-2.6 ppm; Cr-8.01 ppm in sediment) seasons. Also in Lemna minor plant highest concentration was observed during summer season (Cu-29.09 ppm; Zn-19.11 ppm; Ni-5.7 ppm; Cd-1.34 ppm; Cr-9.18 ppm and Pb-9.77 ppm). From these observations, it was found that the sources of heavy metals in Anchar lake were both natural and anthropogenic ones. This study recommended that continuous monitoring of heavy metals (Viz; Cu, Cr, Zn, Ni, Cd and Pb) in water, sediment and other aquatic biota of Anchar lake should be directed to protection of ecological status of the lake and its surrounding area.

  7. Mapping of heavy metals accumulated in plants using submilli-pixe camera

    International Nuclear Information System (INIS)

    Watanabe, R.; Hara, J.; Inoue, C.; Chida, T.; Amartaivan, TS.; Matsuyama, S.; Yamazaki, H.; Ishii, K.

    2004-01-01

    Phytoremediation is a technology for remediation of contaminated soils. In this study, we used a submilli-PIXE camera to analyze plants and soils from a shooting range. Some heavy metals were rapidly and easily detected in these samples. Element dot-maps of the plant show Cu and Pb accumulated in the epidermis of subterranean stems and the venation of leaves. From these findings, it is possible to map the distribution of heavy metals and to detail their location in the plant, using the submilli-PIXE analysis is an effective tool for undertaking phytoremediation research. (author)

  8. Electromagnetic radiation during electrolysis of heavy water

    International Nuclear Information System (INIS)

    Koval'chuk, E.P.; Yanchuk, O.M.; Reshetnyak, O.V.

    1994-01-01

    The radiation in the visible and ultraviolet spectral regions during electrolysis of heavy water on nickel and palladium cathodes was determined for the first time. A sharp jump of the intensity photon flow was observed at a current density of higher than 125 mA/cm 2 . A hypothesis about the relation of the electrochemiluminescence phenomenon during electrolysis of heavy water with the formation of fresh surfaces in consequence of the hydrogenous corrosion of the cathode material is formulated. ((orig.))

  9. Heavy metals in drinking water: Occurrences, implications, and future needs in developing countries

    International Nuclear Information System (INIS)

    Chowdhury, Shakhawat; Mazumder, M.A. Jafar; Al-Attas, Omar; Husain, Tahir

    2016-01-01

    Heavy metals in drinking water pose a threat to human health. Populations are exposed to heavy metals primarily through water consumption, but few heavy metals can bioaccumulate in the human body (e.g., in lipids and the gastrointestinal system) and may induce cancer and other risks. To date, few thousand publications have reported various aspects of heavy metals in drinking water, including the types and quantities of metals in drinking water, their sources, factors affecting their concentrations at exposure points, human exposure, potential risks, and their removal from drinking water. Many developing countries are faced with the challenge of reducing human exposure to heavy metals, mainly due to their limited economic capacities to use advanced technologies for heavy metal removal. This paper aims to review the state of research on heavy metals in drinking water in developing countries; understand their types and variability, sources, exposure, possible health effects, and removal; and analyze the factors contributing to heavy metals in drinking water. This study identifies the current challenges in developing countries, and future research needs to reduce the levels of heavy metals in drinking water. - Highlights: • Co-exposure to multiple heavy metals in drinking water needs better understanding • Low-cost technologies for arsenic removal needs urgent attention • Protonated alginate needs further research for drinking water applications • Community level and PoU devices need improvement and cost reduction • Developing countries are most affected by heavy metals in drinking water

  10. Heavy metals in drinking water: Occurrences, implications, and future needs in developing countries

    Energy Technology Data Exchange (ETDEWEB)

    Chowdhury, Shakhawat, E-mail: Schowdhury@kfupm.edu.sa [Department of Civil and Environmental Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Mazumder, M.A. Jafar [Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Al-Attas, Omar [Department of Civil and Environmental Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Husain, Tahir [Faculty of Engineering and Applied Science, Memorial University of Newfoundland, St. John’s, NL (Canada)

    2016-11-01

    Heavy metals in drinking water pose a threat to human health. Populations are exposed to heavy metals primarily through water consumption, but few heavy metals can bioaccumulate in the human body (e.g., in lipids and the gastrointestinal system) and may induce cancer and other risks. To date, few thousand publications have reported various aspects of heavy metals in drinking water, including the types and quantities of metals in drinking water, their sources, factors affecting their concentrations at exposure points, human exposure, potential risks, and their removal from drinking water. Many developing countries are faced with the challenge of reducing human exposure to heavy metals, mainly due to their limited economic capacities to use advanced technologies for heavy metal removal. This paper aims to review the state of research on heavy metals in drinking water in developing countries; understand their types and variability, sources, exposure, possible health effects, and removal; and analyze the factors contributing to heavy metals in drinking water. This study identifies the current challenges in developing countries, and future research needs to reduce the levels of heavy metals in drinking water. - Highlights: • Co-exposure to multiple heavy metals in drinking water needs better understanding • Low-cost technologies for arsenic removal needs urgent attention • Protonated alginate needs further research for drinking water applications • Community level and PoU devices need improvement and cost reduction • Developing countries are most affected by heavy metals in drinking water.

  11. Concentration of heavy metals and trace elements in soils, waters and vegetables and assessment of health risk in the vicinity of a lignite-fired power plant

    Energy Technology Data Exchange (ETDEWEB)

    Noli, Fotini, E-mail: noli@chem.auth.gr; Tsamos, Panagiotis, E-mail: pktsamos@chem.auth.gr

    2016-09-01

    The pollution of agricultural soils, waters and products in the regions of lignite mines and fired power plants is of great importance. The concentration of As, Βa, Co, Cr, Sr, Sc, Th, U, Zn in soils and waters in the vicinity of a lignite-fired power plant in Northern Greece was determined using Instrumental Neutron Activation Analysis. The determination frequency was every three months during a period of one year in order to evaluate the seasonal impact of the pollution to the environment. Measurements were performed in three locations around the lignite mine as well as in one reference location at a certain distance from the mine. The results, which exhibited a slight seasonal variation, were compared, where possible, with literature values from other countries. The obtained data in most of the cases did not exceed the normal levels and indicated that the investigated area was only slightly contaminated. The concentration of heavy and trace metals was also measured in three common garden crops (tomato, cucumber and parsley) grown in this area. The calculated transfer factors (TF) from soil to vegetables and health risk quotients (HQ) do not denote a health risk. - Highlights: • Seasonal variation of heavy metals concentrations in soils and waters in a lignite mining area. • The elevated concentrations detected by NAA indicating minor contamination of the studied area. • Determination of minor and trace elements in vegetables. • The transfer factors and health risk quotients indicating a possible slight contamination in the area.

  12. Concentration of heavy metals and trace elements in soils, waters and vegetables and assessment of health risk in the vicinity of a lignite-fired power plant

    International Nuclear Information System (INIS)

    Noli, Fotini; Tsamos, Panagiotis

    2016-01-01

    The pollution of agricultural soils, waters and products in the regions of lignite mines and fired power plants is of great importance. The concentration of As, Βa, Co, Cr, Sr, Sc, Th, U, Zn in soils and waters in the vicinity of a lignite-fired power plant in Northern Greece was determined using Instrumental Neutron Activation Analysis. The determination frequency was every three months during a period of one year in order to evaluate the seasonal impact of the pollution to the environment. Measurements were performed in three locations around the lignite mine as well as in one reference location at a certain distance from the mine. The results, which exhibited a slight seasonal variation, were compared, where possible, with literature values from other countries. The obtained data in most of the cases did not exceed the normal levels and indicated that the investigated area was only slightly contaminated. The concentration of heavy and trace metals was also measured in three common garden crops (tomato, cucumber and parsley) grown in this area. The calculated transfer factors (TF) from soil to vegetables and health risk quotients (HQ) do not denote a health risk. - Highlights: • Seasonal variation of heavy metals concentrations in soils and waters in a lignite mining area. • The elevated concentrations detected by NAA indicating minor contamination of the studied area. • Determination of minor and trace elements in vegetables. • The transfer factors and health risk quotients indicating a possible slight contamination in the area.

  13. Assessment of heavy metal pollution of topsoils and plants in the City of Belgrade

    Directory of Open Access Journals (Sweden)

    Andrejić Gordana

    2016-01-01

    Full Text Available In order to assess heavy metal pollution in the city of Belgrade (Serbia concentrations of V, Cr, Mn, Co, Ni, Cu, Zn, Cd and Pb were measured on 18 topsoil samples collected in the proximity to central urban boulevards and in urban parks. In addition, concentrations of specified elements were determined in leaves of three evergreen plant species Buxus sempervirens L., Mahonia aquifolium (Pursh Nutt. and Prunus laurocerasus L. so as to estimate their sensitivity to heavy metal pollution. Even though various types of soils from different quarts of Belgrade were sampled, their heavy metal contents were very similar, with somewhat higher concentrations of almost all elements detected in the proximity to high traffic roads. Generally, concentrations of heavy metals in leaves of investigated plant species paralleled the heavy metal concentrations found in their respective soils and were higher in plants sampled from boulevards then from urban parks. Since investigated plant show no visible injuries induced by detected heavy metal pollution these species are suitable for the successful urban landscaping. [Projekat Ministarstva nauke Republike Srbije, br. 173030

  14. Plutonium Recycle Test Reactor (PRTR). Operating Experience and Supporting R and D, Its Application to Heavy-Water Power Reactor Design and Operation

    Energy Technology Data Exchange (ETDEWEB)

    Harty, H. [Battelle Memorial Institute, Pacific Northwest Laboratories, Richland, WA (United States)

    1968-04-15

    Convincing answers to questions about heavy-water, pressure-tube, power reactors, e.g. pressure-tube serviceability, heavy-water management problems, long-term behaviour of special pressure-tube reactor components, and unique operating maintenance problems (compared to light-water reactors) must be based on actual operating experience with that type of reactor. PRTR operating experience and supporting R and D studies, although not always simple extrapolations to power reactors, can be summarized in a context applicable to future heavy-water power reactors, as follows: 1. Pressure-tube life, in a practical case, need not be limited by creep, gross hydriding, corrosion, or mechanical damage. The possibility that growth of a defect (perhaps service-induced) to a size that is critical under certain operating conditions, remains a primary unknown in pressure- tube life extrapolations. A pressure-tube failure in PRTR (combined with gross release of fuel material) proved only slightly more inconvenient, time consuming, and damaging to the reactor proper, than occurred with a gross failure of a fuel element in PRTR. 2. Routine operating losses of heavy water appear tractable in heavy-water-cooled power reactors; losses from low-pressure systems can be insignificant over the life of a plant. Non-routine losses may prove to be the largest component of loss over the life of a plant. 3. The performance of special components in PRTR, e.g. the calandria and shields, has not deteriorated despite being subjected to non-standard operating conditions. The calandria now contains a light-water reflector with single barrier separation from the heavy-water moderator. The carbon steel shields (containing carbon steel shot) show no deterioration based on pressure drop measurements and piping activation immediately outside the shields. The helium pressurization system (for primary coolant pressurization) remains a high maintenance system, and cannot be recommended for power reactors, based

  15. Nuclear power plant life management processes: Guidelines and practices for heavy water reactors. Report prepared within the framework of the Technical Working Groups on Advanced Technologies for Heavy Water Reactors and on Life Management of Nuclear Power Plants

    International Nuclear Information System (INIS)

    2006-06-01

    The time is right to address nuclear power plant life management and ageing management issues in terms of processes and refurbishments for long term operation and license renewal aspects of heavy water reactors (HWRs) because some HWRs are close to the design life. In general, HWR nuclear power plant (NPP) owners would like to keep their NPPs in service as long as they can be operated safely and economically. This involves the consideration of a number of factors, such as the material condition of the plant, comparison with current safety standards, the socio-political climate and asset management/ business planning considerations. This TECDOC deals with organizational and managerial means to implement effective plan life management (PLiM) into existing plant in operating HWR NPPs. This TECDOC discusses the current trend of PLiM observed in NPPs to date and an overview of PLiM programmes and considerations. This includes key objectives of such programs, regulatory considerations, an overall integrated approach, organizational and technology infrastructure considerations, importance of effective plant data management and finally, human issues related to ageing and finally integration of PLiM with economic planning. Also general approach to HWR PLiM, including the key PLiM processes, life assessment for critical structures and components, conditions assessment of structures and components and obsolescence is mentioned. Technical aspects are described on component specific technology considerations for condition assessment, example of a proactive ageing management programme, and Ontario power generation experiences in appendices. Also country reports from Argentina, Canada, India, the Republic of Korea and Romania are attached in the annex to share practices and experiences to PLiM programme. This TECDOC is primarily addressed to both the management (decision makers) and technical staff (engineers and scientists) of NPP owners/operators and technical support

  16. Heavy metal accumulation in soils, plants, and hair samples: an assessment of heavy metal exposure risks from the consumption of vegetables grown on soils previously irrigated with wastewater.

    Science.gov (United States)

    Massaquoi, Lamin Daddy; Ma, Hui; Liu, Xue Hui; Han, Peng Yu; Zuo, Shu-Mei; Hua, Zhong-Xian; Liu, Dian-Wu

    2015-12-01

    It is common knowledge that soils irrigated with wastewater accumulate heavy metals more than those irrigated with cleaner water sources. However, little is known on metal concentrations in soils and cultivars after the cessation of wastewater use. This study assessed the accumulation and health risk of heavy metals 3 years post-wastewater irrigation in soils, vegetables, and farmers' hair. Soils, vegetables, and hair samples were collected from villages previously irrigating with wastewater (experimental villages) and villages with no history of wastewater irrigation (control villages). Soil samples were digested in a mixture of HCL/HNO3/HCLO4/HF. Plants and hair samples were digested in HNO3/HCLO4 mixture. Inductive coupled plasma-optical emission spectrometer (ICP-OES) was used to determine metal concentrations of digested extracts. Study results indicate a persistence of heavy metal concentration in soils and plants from farms previously irrigated with wastewater. In addition, soils previously irrigated with wastewater were severely contaminated with cadmium. Hair metal concentrations of farmers previously irrigating with wastewater were significantly higher (P metal concentrations in hair samples of farmers previously irrigating with wastewater were not associated with current soil metal concentrations. The study concludes that there is a persistence of heavy metals in soils and plants previously irrigated with wastewater, but high metal concentrations in hair samples of farmers cannot be associated with current soil metal concentrations.

  17. Improved inventory for heavy metal emissions from stationary combustion plants

    DEFF Research Database (Denmark)

    Nielsen, Malene; Nielsen, Ole-Kenneth; Hoffmann, Leif

    On behalf of the Ministry of the Environment DCE at Aarhus University annually reports heavy metals (HM) emissions to the UNECE CLRTAP (United Nations Economic Commission for Europe Convention on Long-Range Transboundary Air Pollution). This report presents updated heavy metal emission factors......-2009. The report also include methodology, references and an uncertainty estimate. In Denmark, stationary combustion plants are among the most important emission sources for heavy metals. Emissions of all heavy metals have decreased considerably (73 % - 92 %) since 1990. The main HM emission sources are coal...

  18. 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)

  19. Decontamination of the RA reactor heavy water system, Annex 9

    International Nuclear Information System (INIS)

    Maksimovic, Z.B.; Nikolic, R.M.; Marinkovic, M.D.; Jelic, Lj.M.

    1963-01-01

    Both stainless steel and aluminium parts of the RA reactor heavy water system system were decontaminated as well as the heavy water itself. System was contaminated with 60 Co. Decontamination factor was determined by activity measurements during distillation. Concentration of the corrosion products in the heavy water was measured by spectrochemical analysis, and found to be 0.1 - 1 mg/l. Chemical analyses of the aluminium and stainless steel surfaces showed that cobalt was adsorbed on the aluminium oxide layer. Water solution of 7%H 3 PO 4 + 2% CrO 3 was used for decontamination of the heavy water system and distillation device. This was found to be the most efficient solvent which does not affect stainless steel corrosion. Decontamination factors achieved were from 60 - 100. Decontamination results enabled determining the distribution of cobalt in the system: 10 Ci on the stainless steel parts, 50 Ci in the heavy water; and above 600 Ci on the fuel and experimental channels. Specific activity of 60 Co was calculated to be 15 Ci/g on the reactor channels, 8 Ci/g on the stainless steel parts and 3 Ci/g in the heavy water. Decontamination of the aluminium parts was not done because it was considered it could initiate corrosion. Since the efficiency of distillation is increased it was expected that permanent distillation would remove most of the activity in the reactor channels

  20. Heavy Metals Pollution on Surface Water Sources in Kaduna ...

    African Journals Online (AJOL)

    This study examine the effects of heavy metal pollutants to aquatic ecosystems and the environment by considering the role of urban, municipal, agricultural, industrial and other anthropogenic processes as sources of heavy metal pollution in surface water sources of Kaduna metropolis. Samples of the polluted water were ...

  1. Heavy water moderated gas-cooled reactors

    International Nuclear Information System (INIS)

    Bailly du Bois, B.; Bernard, J.L.; Naudet, R.; Roche, R.

    1964-01-01

    France has based its main effort for the production of nuclear energy on natural Uranium Graphite-moderated gas-cooled reactors, and has a long term programme for fast reactors, but this country is also engaged in the development of heavy water moderated gas-cooled reactors which appear to present the best middle term prospects. The economy of these reactors, as in the case of Graphite, arises from the use of natural or very slightly enriched Uranium; heavy water can take the best advantages of this fuel cycle and moreover offers considerable development potential because of better reactor performances. A prototype plant EL 4 (70 MW) is under construction and is described in detail in another paper. The present one deals with the programme devoted to the development of this reactor type in France. Reasons for selecting this reactor type are given in the first part: advantages and difficulties are underlined. After reviewing the main technological problems and the Research and Development carried out, results already obtained and points still to be confirmed are reported. The construction of EL 4 is an important step of this programme: it will be a significant demonstration of reactor performances and will afford many experimentation opportunities. Now the design of large power reactors is to be considered. Extension and improvements of the mechanical structures used for EL 4 are under study, as well as alternative concepts. The paper gives some data for a large reactor in the present state of technology, as a result from optimization studies. Technical improvements, especially in the field of materials could lead to even more interesting performances. Some prospects are mentioned for the long run. Investment costs and fuel cycles are discussed in the last part. (authors) [fr

  2. A Review on Heavy Metals (As, Pb, and Hg Uptake by Plants through Phytoremediation

    Directory of Open Access Journals (Sweden)

    Bieby Voijant Tangahu

    2011-01-01

    Full Text Available Heavy metals are among the most important sorts of contaminant in the environment. Several methods already used to clean up the environment from these kinds of contaminants, but most of them are costly and difficult to get optimum results. Currently, phytoremediation is an effective and affordable technological solution used to extract or remove inactive metals and metal pollutants from contaminated soil and water. This technology is environmental friendly and potentially cost effective. This paper aims to compile some information about heavy metals of arsenic, lead, and mercury (As, Pb, and Hg sources, effects and their treatment. It also reviews deeply about phytoremediation technology, including the heavy metal uptake mechanisms and several research studies associated about the topics. Additionally, it describes several sources and the effects of As, Pb, and Hg on the environment, the advantages of this kind of technology for reducing them, and also heavy metal uptake mechanisms in phytoremediation technology as well as the factors affecting the uptake mechanisms. Some recommended plants which are commonly used in phytoremediation and their capability to reduce the contaminant are also reported.

  3. Heavy metals in drinking water: Occurrences, implications, and future needs in developing countries.

    Science.gov (United States)

    Chowdhury, Shakhawat; Mazumder, M A Jafar; Al-Attas, Omar; Husain, Tahir

    2016-11-01

    Heavy metals in drinking water pose a threat to human health. Populations are exposed to heavy metals primarily through water consumption, but few heavy metals can bioaccumulate in the human body (e.g., in lipids and the gastrointestinal system) and may induce cancer and other risks. To date, few thousand publications have reported various aspects of heavy metals in drinking water, including the types and quantities of metals in drinking water, their sources, factors affecting their concentrations at exposure points, human exposure, potential risks, and their removal from drinking water. Many developing countries are faced with the challenge of reducing human exposure to heavy metals, mainly due to their limited economic capacities to use advanced technologies for heavy metal removal. This paper aims to review the state of research on heavy metals in drinking water in developing countries; understand their types and variability, sources, exposure, possible health effects, and removal; and analyze the factors contributing to heavy metals in drinking water. This study identifies the current challenges in developing countries, and future research needs to reduce the levels of heavy metals in drinking water. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Arsenic and other heavy metal accumulation in plants and algae growing naturally in contaminated area of West Bengal, India.

    Science.gov (United States)

    Singh, N K; Raghubanshi, A S; Upadhyay, A K; Rai, U N

    2016-08-01

    The present study was conducted to quantify the arsenic (As) and other heavy metal concentrations in the plants and algae growing naturally in As contaminated blocks of North-24-Pargana and Nandia district, West Bengal, India to assess their bioaccumulation potential. The plant species included five macrophytes and five algae were collected from the nine selected sites for estimation of As and other heavy metals accumulated therein by using Inductively Coupled Plasma Mass Spectrophotometer (ICP-MS). Results revealed that maximum As concentration (117mgkg(-1)) was recorded in the agricultural soil at the Barasat followed by Beliaghat (111mgkg(-1)) sites of North-24-Pargana. Similarly, concentration of selenium (Si, 249mgkg(-1)), lead (Pb, 79.4mgkg(-1)), chromium (Cr, 138mgkg(-1)) was also found maximum in the soil at Barasat and cadmium (Cd, 163mgkg(-1)) nickel (Ni, 36.5mgkg(-1)) at Vijaynagar site. Among the macrophytes, Eichhornia crassipes found more dominating species in As contaminated area and accumulate As (597mgkg(-1)) in the shoot at kanchrapara site. The Lemna minor found to accumulate maximum As (735mgkg(-1)) in the leaves at Sonadanga and Pistia stratiotes accumulated minimum As (24.5mgkg(-1)) in the fronds from Ranaghat site. In case of diatoms, maximum As (760mgkg(-1)) was accumulated at Kanchrapara site followed by Hydrodictiyon reticulatum (403mgkg(-1)) at the Ranaghat site. High concentration of As and other heavy metal in soil indicates long term effects of irrigation with contaminated ground water, however, high concentration of heavy metals in naturally growing plants and algae revealed their mobilization through leaching and possible food chain contamination. Therefore, efficient heavy metal accumulator macrophytes Eichhornia crassipes, Lemna minor, Spirodela polyrhiza may be exploited in removing metals from contaminated water by developing a plant based treatment system. However, As accumulator algal species may be used as a bioresource for

  5. Determination of selected heavy metals in inland fresh water of ...

    African Journals Online (AJOL)

    Agadaga

    Key words: Heavy metals, freshwater, concentrations, quality, variation, distribution. ... prevalence of heavy metals in inland water of lower River. Niger drain are scarce ..... Niger waters at Ajaokuta were found to be low and within guideline.

  6. Development and implementation of the heavy water program at Bruce Power

    International Nuclear Information System (INIS)

    Davloor, R.; Bourassa, C.

    2014-01-01

    Bruce Power operates 8 pressurized heavy water reactor units requiring more than 6000 mega grams (Mg) of heavy water. A Heavy Water Management Program that has been developed to administer this asset over the past 3 years. Through a corporate management system the Program provides governance, oversight and support to the stations. It is implemented through organizational structure, program and procedure documents and an information management system that provides benchmarked metrics, business intelligence and analytics for decision making and prediction. The program drives initiatives such as major maintenance activities, capital programs, detritiation strategies and ensures heavy water systems readiness for outages and rehabilitation of units. (author)

  7. Development and implementation of the heavy water program at Bruce Power

    Energy Technology Data Exchange (ETDEWEB)

    Davloor, R.; Bourassa, C., E-mail: ram.davloor@brucepower.com, E-mail: carl.bourassa@brucepower.com [Bruce Power, Tiverton, ON (Canada)

    2014-07-01

    Bruce Power operates 8 pressurized heavy water reactor units requiring more than 6000 mega grams (Mg) of heavy water. A Heavy Water Management Program that has been developed to administer this asset over the past 3 years. Through a corporate management system the Program provides governance, oversight and support to the stations. It is implemented through organizational structure, program and procedure documents and an information management system that provides benchmarked metrics, business intelligence and analytics for decision making and prediction. The program drives initiatives such as major maintenance activities, capital programs, detritiation strategies and ensures heavy water systems readiness for outages and rehabilitation of units. (author)

  8. Use of non-hyperaccumulator plant species for the phytoextraction of heavy metals using chelating agents

    Directory of Open Access Journals (Sweden)

    Lucas Anjos Souza

    2013-08-01

    Full Text Available Soil contamination by heavy metals is a challenge faced by many countries, and engineering technologies to solve this problem are expensive and can cause negative impacts on the environment. One way to minimise the levels of heavy metals in the soil is to use plants that can absorb and accumulate heavy metals into harvestable parts, a process called phytoextraction. Typical plant species used in research involving phytoextraction are heavy metal hyperaccumulators, but plants from this group are not good biomass producers and grow more slowly than most species; thus, they have an important role in helping scientists understand the mechanisms involved in accumulating high amounts of heavy metals without developing symptoms or dying. However, because of their slow growth, it is not practical to use these species for phytoextraction. An alternative approach is to use non-hyperaccumulator plants assisted by chelating agents, which may improve the ability of plants to accumulate more heavy metals than they would naturally. Chelating agents can be synthetic or organic acids, and the advantages and disadvantages of their use in improving the phytoextraction potential of non-hyperaccumulator plants are discussed in this article. We hope to draw attention to ways to improve the phytoextraction potential of non-hyperaccumulator plants that produce a large amount of biomass and to stimulate more research on phytoextraction-inducing substances.

  9. Seismic analysis of two 1050 mm diameter heavy water upgrading towers for 235 MWe Kaiga Atomic Power Plant Site

    International Nuclear Information System (INIS)

    Soni, R.S.; Kushwaha, H.S.; Mahajan, S.C.; Kakodkar, A.; Narwaria, Suresh; Vardarajan, T.G.; Sadhukhan, H.K.

    1992-01-01

    This report deals with the analysis carried out for the evaluation of earthquake induced stresses and deflections in two 1050 mm diameter heavy water upgrading towers for Kaiga Atomic Power Plant Site. The analysis of upgrading tower has been carried out for two mutually perpendicular horizontal excitations and one vertical excitation applied simultaneously. The upgrading towers have been analysed using beam model taking into account soil-structure interaction. Response spectrum analysis has been carried out using site spectra for 235 MWe Kaiga reactor site. The seismic analysis has been performed for both the towers with supporting structure along with concrete pedestals and raft foundation. The towers have been checked for its stability due to compressive stresses to avoid buckling so that the nearby safety related structures are not geopardised in the event of safe shutdown earthquake (SSE) loading. (author). 14 refs., 12 figs., 18 tabs

  10. Study of the heavy water regeneration processes; Studija procesa za regeneraciju teske vode

    Energy Technology Data Exchange (ETDEWEB)

    Cavcic, E [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

    1965-11-15

    Experience derived from heavy water reactor operation showed degradation and dilution of heavy water to be inevitable depends on the type of reactor. Dilution of heavy water during operation of the RA and the RB reactors is shown in this report. Principles and procedures of heavy water regeneration by electrolysis, fractional distillation, cleaning, prevention of tritium contamination are described as well as separation columns.

  11. Comprehensive cooling water study annual report. Volume II: introduction and site description, Savannah River Plant

    International Nuclear Information System (INIS)

    Gladden, J.B.; Lower, M.W.; Mackey, H.E.; Specht, W.L.; Wilde, E.W.

    1985-07-01

    The Comprehensive Cooling Water Study was initiated in 1983 to evaluate the environmental effecs of the intake and release of cooling water on the structure and function of aquatic ecosystems at the Savannah River Plant. This report presents the results from the first year of the two year study and also summarizes results from previous studies on aquatic ecosystems of the Savannah River Plant. Five major program elements are addressed: water quality, radionuclide and heavy metal transport, wetlands ecology, aquatic ecology, and endangered species. 63 refs., 13 figs., 7 tabs

  12. The status of improved pressurized heavy water reactor development - A new option for PHWR -

    International Nuclear Information System (INIS)

    Park, Tae Keun; Yeo, Ji Won

    1996-03-01

    Currently, the 900 MWe class Improved Pressurized Heavy Water Reactor (PHWR), which is a type of CANDU reactor based on the systems and components of operating CANDU plants, is under development. The improved PHWR has a 480 fuel channel calandria, uses 37 element natural uranium fuel bundles and has a single unit containment. Adaptation of a steel-lined containment structure and improved containment isolation systems permit a reduced exclusion area boundary (EAB) compared to the existing larger capacity CANDU reactors (Darlington, Bruce B). The improved PHWR buildings are arranged to achieve minimum spacing between reactor units. Plant safety and economy are increased through various design changes based on the operating experience of existing CANDU plants. 4 refs. (Author)

  13. Removal heavy metals and sulphate from waste waters by sulphate-reducing bacteria

    Directory of Open Access Journals (Sweden)

    Kušnierová Mária

    2000-09-01

    Full Text Available This article is devoted to the process of bacterial sulphate reduction, which is used to removal of heavy metals and sulphate ions from waste waters.The life of animals and plants depends on the existence of microscopic organisms – microorganisms (MO, which play an important role in cycle changes of biogenic elements on the earth. The sulphur cycle in the nature is considered as one of the oldest and most significant biological systems (Fig. 1. The sulphate-reducing bacteria (SRB miss the assimilatory part of the cycle and produce sulphides. The microbial population of this dissimilatory part is called “sulfuretum”. The SRB can be found in anaerobic mud and sediments of freshwater, thermal or non-thermal sulphur springs, mining waters from sulphide deposits, oil deposits, sea and ocean beds, and in the gastrointestinal tract of man and animals. The SRB represent a group of chemoorganotrophic, strictly anaerobic and gramnegative bacteria, which exhibit a great morphological and physiological diversity. Despite of their considerable morphological variety, they have one property in common, which is the ability to utilise preferentially sulphates (occasionally sulphites, thiosulphates, tetrathionates as electron acceptors, which are reduced to sulphides, during anaerobic respiration. The electron donors in these processes are simple organic compounds as lactate, malate, etc.,(heterotrophically reduction or gaseous hydrogen (autotrophically reduction. SRB can produce a considerable amount of hydrogen sulphide, which reacts easily in aqueous solution with the cations of heavy metals, forming metal sulphides that have low solubility. The bacterial sulphate reduction can be used for the treatment of acid mine drainage waters, which is considered to be the major problem associated with mining activities.In order to remove heavy metals from waste waters, e.g., from galvanizing plants, mine waters (Smolnik, Šobov locality and metallurgic plants (works

  14. Conceptual designing of reduced-moderation water reactor with heavy water coolant

    Energy Technology Data Exchange (ETDEWEB)

    Hibi, Kohki; Shimada, Shoichiro; Okubo, Tsutomu E-mail: okubo@hems.jaeri.go.jp; Iwamura, Takamichi; Wada, Shigeyuki

    2001-12-01

    The conceptual designing of reduced-moderation water reactors, i.e. advanced water-cooled reactors using plutonium mixed-oxide fuel with high conversion ratios more than 1.0 and negative void reactivity coefficients, has been carried out. The core is designed on the concept of a pressurized water reactor with a heavy water coolant and a triangular tight lattice fuel pin arrangement. The seed fuel assembly has an internal blanket region inside the seed fuel region as well as upper and lower blanket regions (i.e. an axial heterogeneous core). The radial blanket fuel assemblies are introduced in a checkerboard pattern among the seed fuel assemblies (i.e. a radial heterogeneous core). The radial blanket region is shorter than the seed fuel region. This study shows that the heavy water moderated core can achieve negative void reactivity coefficients and conversion ratios of 1.06-1.11.

  15. SO2 pollution of heavy oil-fired steam power plants in Iran

    International Nuclear Information System (INIS)

    Nazari, S.; Shahhoseini, O.; Sohrabi-Kashani, A.; Davari, S.; Sahabi, H.; Rezaeian, A.

    2012-01-01

    Steam power plants using heavy oil provided about 17.4%, equivalent to 35.49 TWh, of electricity in Iran in 2007. However, having 1.55–3.5 weight percentage of sulfur, heavy oil produces SO 2 pollutant. Utilization of Flue Gas Desulfurization systems (FGD) in Iran's steam power plants is not common and thereby, this pollutant is dispersed in the atmosphere easily. In 2007, the average emission factor of SO 2 pollutant for steam power plants was 15.27 g/kWh, which means regarding the amount of electricity generated by steam power plants using heavy oil, 541,000 Mg of this pollutant was produced. In this study, mass distribution of SO 2 in terms of Mg/yr is considered and dispersion of this pollutant in each of the 16 steam power plants under study is modeled using Atmospheric Dispersion Modeling System (ADMS). Details of this study are demonstrated using Geographical Information System (GIS) software, ArcGIS. Finally, the average emission factor of SO 2 and the emission of it in Iran's steam power plants as well as SO 2 emission reduction programs of this country are compared with their alternatives in Turkey and China.

  16. Threat of heavy metal pollution in halophytic and mangrove plants of Tamil Nadu, India

    Energy Technology Data Exchange (ETDEWEB)

    Agoramoorthy, Govindasamy; Chen, F.-A. [Department of Pharmacy, Tajen University, Yanpu, Pingtung 907, Taiwan (China); Hsu, Minna J. [Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung 80424, Taiwan (China)], E-mail: hsumin@mail.nsysu.edu.tw

    2008-09-15

    Mangrove and halophytic plants occur along the coastal areas of Tamil Nadu, south India and these plants have been used in traditional medicine for centuries. Heavy metals are known to pose a potential threat to terrestrial and aquatic biota. However, little is known on the toxic levels of heavy metals found in mangrove and halophytic plants that are used in traditional medicine in India. To understand heavy metal toxicity, we investigated the bioconcentration factors (BCF) of heavy metals in leaves collected from eight mangroves and five halophytes in the protected Pichavaram mangrove forest reserve in Tamil Nadu State, south India. Data presented in this paper describe the impact of essential (Cu, Fe, Mg, Mn and Zn) and non-essential/environmentally toxic trace metals (Hg, Pb and Sn) in mangrove and halophytic medicinal plants. The concentrations of Pb among 13 plant species were higher than the normal range of contamination reported for plants. The average concentration of Hg in the halophytic plants (0.43 {+-} 0.37 {mu}g/g) was seven times higher than mangrove plants (0.06 {+-} 0.03 {mu}g/g) and it indicated pollutants from industrial sources affecting halophytes more than mangroves. - Metal effects occur in India's mangrove ecosystem.

  17. Threat of heavy metal pollution in halophytic and mangrove plants of Tamil Nadu, India

    International Nuclear Information System (INIS)

    Agoramoorthy, Govindasamy; Chen, F.-A.; Hsu, Minna J.

    2008-01-01

    Mangrove and halophytic plants occur along the coastal areas of Tamil Nadu, south India and these plants have been used in traditional medicine for centuries. Heavy metals are known to pose a potential threat to terrestrial and aquatic biota. However, little is known on the toxic levels of heavy metals found in mangrove and halophytic plants that are used in traditional medicine in India. To understand heavy metal toxicity, we investigated the bioconcentration factors (BCF) of heavy metals in leaves collected from eight mangroves and five halophytes in the protected Pichavaram mangrove forest reserve in Tamil Nadu State, south India. Data presented in this paper describe the impact of essential (Cu, Fe, Mg, Mn and Zn) and non-essential/environmentally toxic trace metals (Hg, Pb and Sn) in mangrove and halophytic medicinal plants. The concentrations of Pb among 13 plant species were higher than the normal range of contamination reported for plants. The average concentration of Hg in the halophytic plants (0.43 ± 0.37 μg/g) was seven times higher than mangrove plants (0.06 ± 0.03 μg/g) and it indicated pollutants from industrial sources affecting halophytes more than mangroves. - Metal effects occur in India's mangrove ecosystem

  18. The levels of heavy metals in water and all aquatic in Ismailia canal, (Egypt) compared with the international permissible limits and accumulative studies for these metals in biota

    International Nuclear Information System (INIS)

    Saleh, H.M.; Moloukhia, H.; Belacy, N.; Abd El-Rahman, G.A.

    2011-01-01

    The concentration of Pb, Cd, Cu, Zu, Ni, Fe and Mn were determined in water, and in different organs of fishes, bivalves, snails and plants in Ismailia canal, Egypt. Moreover, accumulation of the investigated heavy metals by aquatic biota in Ismailia canal and the concentration factor values for this accumulation were calculated to qualify the degree of pollution and compare these levels with the international permissible limits. Results showed that Pb, Cd, Cu and Zn were exceeded the permissible limits especially in the industrial area of Abu- Zaabal, Kalubia governorate. The relative order of heavy metal levels in the canal water was: Fe>Mn>Pb>Zn>Ni>Cd>Cu.Accumulation of heavy metals by the aquatic biota was determined. The accumulation of heavy metals by common snails, namely physa acuta and biomphalaria alexandrina and the bivalve oyster Caelatura (caelatura) companyoi was found mainly in the edible parts (soft parts), whereas, the accumulation by their shells, which are mainly formed of calcium carbonate was via adsorption and surface complexation, since all the accumulated heavy metals were released by adding 0.1 M HCl for few minutes . Moreover, accumulation of heavy metals by common plants namely water hyacinth plant (Eichhornia crassipes) and freshwater weeds were determined. It was found that the accumulation of heavy metals was higher in roots than in leaves. On the other hand, the accumulation of heavy metals by common fish namely, Oreochromis niloticus (Nile Tilapia) was measured in its organs : muscles, liver, gills and gonads. It was found that there is variation of distribution of heavy metals among fish organs. Since the high accumulation of heavy metals among the investigated biota, they can be used as biological indicator for pollution of heavy metals in aquatic ecosystem . The average values and standard deviation for all measurements were determined. Data obtained were compared with the permissible concentrations of the environmental protection

  19. Heavy Metals in Crop Plants: Transport and Redistribution Processes on the Whole Plant Level

    Directory of Open Access Journals (Sweden)

    Valérie Page

    2015-09-01

    Full Text Available Copper, zinc, manganese, iron, nickel and molybdenum are essential micronutrients for plants. However, when present in excess they may damage the plant or decrease the quality of harvested plant products. Some other heavy metals such as cadmium, lead or mercury are not needed by plants and represent pollutants. The uptake into the roots, the loading into the xylem, the acropetal transport to the shoot with the transpiration stream and the further redistribution in the phloem are crucial for the distribution in aerial plant parts. This review is focused on long-distance transport of heavy metals via xylem and phloem and on interactions between the two transport systems. Phloem transport is the basis for the redistribution within the shoot and for the accumulation in fruits and seeds. Solutes may be transferred from the xylem to the phloem (e.g., in the small bundles in stems of cereals, in minor leaf veins. Nickel is highly phloem-mobile and directed to expanding plant parts. Zinc and to a lesser degree also cadmium are also mobile in the phloem and accumulate in meristems (root tips, shoot apex, axillary buds. Iron and manganese are characterized by poor phloem mobility and are retained in older leaves.

  20. Heavy water moderated reactors advances and challenges

    International Nuclear Information System (INIS)

    Meneley, D.A.; Olmstead, R.A.; Yu, A.M.; Dastur, A.R.; Yu, S.K.W.

    1994-01-01

    Nuclear energy is now considered a key contributor to world electricity production, with total installed capacity nearly equal to that of hydraulic power. Nevertheless, many important challenges lie ahead. Paramount among these is gaining public acceptance: this paper makes the basic assumption that public acceptance will improve if, and only if, nuclear power plants are operated safely and economically over an extended period of time. The first task, therefore, is to ensure that these prerequisites to public acceptance are met. Other issues relate to the many aspects of economics associated with nuclear power, include capital cost, operation cost, plant performance and the risk to the owner's investment. Financing is a further challenge to the expansion of nuclear power. While the ability to finance a project is strongly dependent on meeting public acceptance and economic challenges, substantial localisation of design and manufacture is often essential to acceptance by the purchaser. The neutron efficient heavy water moderated CANDU with its unique tube reactor is considered to be particularly well qualified to respond to these market challenges. Enhanced safety can be achieved through simplification of safety systems, design of the moderator and shield water systems to mitigate severe accident events, and the increased use of passive systems. Economics are improved through reduction in both capital and operating costs, achieved through the application of state-of-the-art technologies and economy of scale. Modular features of the design enhance the potential for local manufacture. Advanced fuel cycles offer reduction in both capital costs and fuelling costs. These cycles, including slightly enriched uranium and low grade fuels from reprocessing plants can serve to increase reactor output, reduce fuelling cost and reduce waste production, while extending resource utilisation. 1 ref., 1 tab

  1. Assessment of EPRI water chemistry guidelines for new nuclear power plants

    International Nuclear Information System (INIS)

    Reid Richard; Kim Karen; McCree, Anisa; Eaker, Richard; Sawochka, Steve; Giannelli, Joe

    2012-09-01

    Water chemistry control technologies for nuclear power plants have been significantly enhanced over the past few decades to improve material and equipment reliability and fuel performance, and to minimize radionuclide production and transport. Chemistry Guidelines have been developed by the Electric Power Research Institute (EPRI) for currently operating plants and have been intermittently revised over the past twenty-five years for the protection of systems and components and for radiation management. As new plants are being designed for improved safety and increased power production, it is important to ensure that the designs consider implementation of state-of-the-art, industry developed water chemistry controls. In parallel, the industry will need to consider and update water chemistry guidelines as well as plant startup and operational strategies based on the advanced plant designs. EPRI has performed assessments of water chemistry control guidance or assumptions provided in design and licensing documents for several advanced plant designs. These designs include: Westinghouse AP1000 Pressurized Water Reactor AREVA US-EPR Pressurized Water Reactor Mitsubishi Nuclear Energy Systems/Mitsubishi Heavy Industries Advanced Pressurized Water Reactor Korea Hydro and Nuclear Power APR1400 Pressurized Water Reactor Toshiba Advanced Boiling Water Reactor (ABWR) General Electric-Hitachi Economic Simplified Boiling Water Reactor (ESBWR) The intent of these assessments was to identify key design differences in each of the new plant designs relative to the current operating fleet and to identify differences in water chemistry specifications or design assumptions provided in design and licensing documents for the plants in comparison to current EPRI Water Chemistry Guidelines. This paper provides a summary of the key results of these assessments. The fundamental design and operation of the advanced plants is similar to the currently operating fleet. As such, the new plants are

  2. Conceptual design of a large heavy water reactor for US siting

    International Nuclear Information System (INIS)

    Shapiro, N.L.; Jesick, J.F.

    1979-09-01

    Information is presented concerning fuel management and safety and licensing assessment of the pressurized heavy water reactor; and commercial introduction of the pressurized heavy water reactor in the United States

  3. 76 FR 52994 - Application for a License To Export Heavy Water

    Science.gov (United States)

    2011-08-24

    ... NUCLEAR REGULATORY COMMISSION Application for a License To Export Heavy Water Pursuant to 10 CFR... (liters). producing an active water). pharmaceutical ingredient known as CTP-499, which incorporates heavy water as the source of deuterium to achieve the hydrogen-deuterium exchange. November 30, 2010 December...

  4. Loss of coolant analysis for CIRENE-LATINA heavy water reactor

    International Nuclear Information System (INIS)

    Chiantore, B.; Dubbini, M.; Proto, G.

    1978-01-01

    CIRENE is a heavy-water moderated, boiling water cooled pressure tube reactor. Fuel is natural uranium. A variety of breaks in the primary coolant system have been postulated for the analysis of the CIRENE Latina Plant (now under construction) such as double-end break of inlet header, downcomer, steam line and inlet feeders. The basic tool for analysis is the TILT-N Code which has been purposely developed for simulating the nuclear, thermal and hydrodynamic behaviour of the CIRENE core and associated heat transport system. An extensive full-scale test programme has been carried out by CNEN and CISE which fully confirms the adequacy of the model. The main results of the analysis show that maximum temperatures are far from those leading to significant fuel damage and that adequate core cooling is provided over the whole transient. (author)

  5. Spatiotemporal Analysis of Heavy Metal Water Pollution in Transitional China

    Directory of Open Access Journals (Sweden)

    Huixuan Li

    2015-07-01

    Full Text Available China’s socioeconomic transitions have dramatically accelerated its economic growth in last three decades, but also companioned with continuous environmental degradation. This study will advance the knowledge of heavy metal water pollution in China from a spatial–temporal perspective. Specifically, this study addressed the following: (1 spatial patterns of heavy metal water pollution levels were analyzed using data of prefecture-level cities from 2004 to 2011; and (2 spatial statistical methods were used to examine the underlying socioeconomic and physical factors behind water pollution including socioeconomic transitions (industrialization, urbanization, globalization and economic development, and environmental characteristic (natural resources, hydrology and vegetation coverage. The results show that only Cr pollution levels increased over the years. The individual pollution levels of the other four heavy metals, As, Cd, Hg, and Pb, declined. High heavy metal water pollution levels are closely associated with both anthropogenic activities and physical environments, in particular abundant mineral resources and industrialization prosperity. On the other hand, economic development and urbanization play important roles in controlling water pollution problems. The analytical findings will provide valuable information for policy-makers to initiate and adjust protocols and strategies for protecting water sources and controlling water pollution; thus improving the quality of living environments.

  6. Absorption characteristics of compound heavy metals vanadium, chromium, and cadmium in water by emergent macrophytes and its combinations.

    Science.gov (United States)

    Lin, Hai; Liu, Junfei; Dong, Yingbo; Ren, Kaiqiang; Zhang, Yu

    2018-04-20

    The aim of the present study was to investigate three kinds of emergent macrophytes, i.e., Acorus calamus L., Phragmites communis Trin., and Alternanthera philoxeroides (Mart.) Griseb and their combination patterns on their removal efficiency of compound heavy metals (vanadium, chromium, and cadmium) from synthetic aqueous. The results showed that the optimal single-species for compound heavy metals removal was Acorus calamus L. and during experiment period, the average removal efficiency of V 5+ , Cr 6+ , and Cd 2+ was 52.4, 46.8, and 90.0%, respectively. Combination C (the quality ratio of Acorus calamus L., Phragmites communis Trin., and Alternanthera philoxeroides (Mart.) Griseb is 2:1:1) had the highest removal efficiency on compound heavy metals among three groups and the average removal efficiency of V 5+ , Cr 6+ , and Cd 2+ was 18.0, 70.0, and 95.1%, respectively. The highest efficiency of combination C on V 5+ removal was lower than single Alternanthera philoxeroides (Mart.) Griseb group; this may be an existing antagonism in different plants. Heavy metals of V 5+ , Cr 6+ , and Cd 2+ had an obviously positive effect on SOD, CAT, and POD of emergent macrophytes. From these results, we conclude that in a phytoremediation for the removal of compound heavy metals where V was dominated pollution in water, the use of Acorus calamus L. species rather than a mixture of several plants should be suggested. When heavy metal pollution was dominated by Cr and Cd, group C rather than a single plant species should be used.

  7. Multi-purpose hydrogen isotopes separation plant design

    Energy Technology Data Exchange (ETDEWEB)

    Boniface, H.A.; Gnanapragasam, N.V.; Ryland, D.K.; Suppiah, S.; Castillo, I. [Atomic Energy of Canada Limited - AECL, Chalk River, ON (Canada)

    2015-03-15

    There is a potential interest at AECL's Chalk River Laboratories to remove tritium from moderately tritiated light water and to reclaim tritiated, downgraded heavy water. With only a few limitations, a single CECE (Combined Electrolysis and Catalytic Exchange) process configuration can be designed to remove tritium from heavy water or light water and upgrade heavy water. Such a design would have some restrictions on the nature of the feed-stock and tritium product, but could produce essentially tritium-free light or heavy water that is chemically pure. The extracted tritium is produced as a small quantity of tritiated heavy water. The overall plant capacity is fixed by the total amount of electrolysis and volume of catalyst. In this proposal, with 60 kA of electrolysis a throughput of 15 kg*h{sup -1} light water for detritiation, about 4 kg*h{sup -1} of heavy water for detritiation and about 27 kg*h{sup -1} of 98% heavy water for upgrading can be processed. Such a plant requires about 1,000 liters of AECL isotope exchange catalyst. The general design features and details of this multi-purpose CECE process are described in this paper, based on some practical choices of design criteria. In addition, we outline the small differences that must be accommodated and some compromises that must be made to make the plant capable of such flexible operation. (authors)

  8. Operation management of the prototype heavy water reactor 'Fugen'

    Energy Technology Data Exchange (ETDEWEB)

    Muramatsu, Akira; Takei, Hiroaki; Iwanaga, Shigeru; Noda, Masao; Hara, Hidemi (Power Reactor and Nuclear Fuel Development Corp., Tokyo (Japan))

    1983-09-01

    The advanced thermal reactor Fugen power station has continued almost smooth operation since it began the full scale operation as the first homemade power reactor in Japan in March, 1979. In the initial period of operation, some troubles were experienced, but now, it can be said that the operational techniques of heavy water-moderated, boiling light water-cooled, pressure tube type reactors have been established, through the improvement of the operational method and equipment, and the operational experience. Also, the verification of the operational ability, maintainability, reliability and safety of this new type reactor, that is the mission of the prototype reactor, achieved steadily the good results. Hereafter, the verification of operational performance is the main objective because it is required for the design, construction and operation of the demonstration reactor. The organization for the operation management and operation, the communication at the time of the abnormality, the operation of the plant, that is, start up, stop and the operation at the rated output, the works during plant stoppage, the operation at the time of the plant abnormality, the operation of waste treatment facility and others, the improvement of the operational method, and the education and training of operators are reported.

  9. Contribution to the development of a new process for heavy water production

    International Nuclear Information System (INIS)

    Lefrancois, Bernard

    1970-01-01

    This research thesis addresses the development of a new process for the production of heavy water by using an ammoniac-hydrogen based process. The author first presents and comments the results of fundamental studies on the composition of present phases, and on the coefficient of separation of isotopic exchange reaction. He shows that experiments and calculations allows the two main workshops to be sized: the isotopic exchange workshop, and the ammoniac dissociation workshop. Then, he examines how it is possible to calculate the plant general scheme, and to optimise the main parameters

  10. Integration of a heavy water industry to the NH3 national industry

    International Nuclear Information System (INIS)

    Montes D, N.L.

    1977-01-01

    The heavy water production in Mexico is one of the problems which need an immediate solution, according to an analysis of the studies mentioned in the bibliography, among the production processes which can be introduced in Mexico, the hydrogen-amine one presents the greatest technical and economical advantages. The adoption of such a process will pose different problems: coupling to synthesis plant and selection of the kind of amine which will be used in the process (ammonia or methylamine)with the respective implications that the present work has given. (author)

  11. Cooling water treatment for heavy water project (Paper No. 6.9)

    International Nuclear Information System (INIS)

    Valsangkar, H.N.

    1992-01-01

    With minor exceptions, water is the preferred industrial medium for the removal of unwanted heat from process systems. The application of various chemical treatments is required to protect the system from water related and process related problems of corrosion, scale and deposition and biofouling. The paper discusses the cooling water problems for heavy water industries along with the impact caused by associated fertilizer units. (author). 6 figs

  12. Assessment of EPRI water chemistry guidelines for new nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K.; Fruzzetti, K.; Garcia, S. [Electric Power Research Inst., Palo Alto, California (United States); Eaker, R. [Richard W. Eaker, LLC, Matthews, North Carolina (United States); Giannelli, J.; Tangen, J. [Finetech, Inc., Parsippany, New Jersey (United States); Gorman, J.; Marks, C. [Dominion Engineering, Inc., Reston, Virginia (United States); Sawochka, S. [NWT Corp., San Jose, California (United States)

    2010-07-01

    Water chemistry control technologies for nuclear power plants have been significantly enhanced over the past few decades to improve material and equipment reliability and fuel performance, and to minimize radionuclide production and transport. Chemistry Guidelines have been developed by the Electric Power Research Institute (EPRI) for current operating plants and have been intermittently revised over the past twenty-five years for the protection of systems and components and for radiation management. As new plants are being designed for improved safety and increased power production, it is important to ensure that the designs consider implementation of industry approved water chemistry controls. In parallel, the industry will need to consider and develop updated water chemistry guidelines as well as plant startup and operational strategies based on the advanced plant designs. In 2010, EPRI began to assess chemistry control strategies at advanced plants, based on the Design Control Documents (DCDs), Combined Construction and Operating License Applications (COLA), and operating experiences (where they exist) against current Water Chemistry Guidelines. Based on this assessment, differences between planned chemistry operations at new plants and the current Guidelines will be identified. This assessment will form the basis of future activities to address these differences. The project will also assess and provide, as feasible, water chemistry guidance for startup and hot functional testing of the new plants. EPRI will initially assess the GE-Hitachi/Toshiba ABWR and the Westinghouse AP1000 designs. EPRI subsequently plans to assess other plant designs such as the AREVA U.S. EPR, Mitsubishi Heavy Industries (MHI) U.S. APWR, and GE-Hitachi (GE-H) ESBWR. This paper discusses the 2010 assessments of the ABWR and AP1000. (author)

  13. Assessment of EPRI water chemistry guidelines for new nuclear power plants

    International Nuclear Information System (INIS)

    Kim, K.; Fruzzetti, K.; Garcia, S.; Eaker, R.; Giannelli, J.; Tangen, J.; Gorman, J.; Marks, C.; Sawochka, S.

    2010-01-01

    Water chemistry control technologies for nuclear power plants have been significantly enhanced over the past few decades to improve material and equipment reliability and fuel performance, and to minimize radionuclide production and transport. Chemistry Guidelines have been developed by the Electric Power Research Institute (EPRI) for current operating plants and have been intermittently revised over the past twenty-five years for the protection of systems and components and for radiation management. As new plants are being designed for improved safety and increased power production, it is important to ensure that the designs consider implementation of industry approved water chemistry controls. In parallel, the industry will need to consider and develop updated water chemistry guidelines as well as plant startup and operational strategies based on the advanced plant designs. In 2010, EPRI began to assess chemistry control strategies at advanced plants, based on the Design Control Documents (DCDs), Combined Construction and Operating License Applications (COLA), and operating experiences (where they exist) against current Water Chemistry Guidelines. Based on this assessment, differences between planned chemistry operations at new plants and the current Guidelines will be identified. This assessment will form the basis of future activities to address these differences. The project will also assess and provide, as feasible, water chemistry guidance for startup and hot functional testing of the new plants. EPRI will initially assess the GE-Hitachi/Toshiba ABWR and the Westinghouse AP1000 designs. EPRI subsequently plans to assess other plant designs such as the AREVA U.S. EPR, Mitsubishi Heavy Industries (MHI) U.S. APWR, and GE-Hitachi (GE-H) ESBWR. This paper discusses the 2010 assessments of the ABWR and AP1000. (author)

  14. Heavy water technology and its contribution to energy sustainability

    International Nuclear Information System (INIS)

    MacDiarmid, H.; Alizadeh, A.; Hopwood, J.; Duffey, R.

    2009-01-01

    Full text: As the global nuclear industry expands several markets are exploring avenues and technologies to underpin energy security. Heavy water reactors are the most versatile power reactors in the world. They have the potential to extend resource utilization significantly, to allow countries with developing industrial infrastructures access to clean and abundant energy, and to destroy long-lived nuclear waste. These benefits are available by choosing from an array of possible fuel cycles. Several factors, including Canada's early focus on heavy-water technology, limited heavy-industry infrastructure at the time, and a desire for both technological autonomy and energy self-sufficiency, contributed to the creation of the first commercial heavy water reactor in 1962. With the maturation of the industry, the unique design features of the now-familiar product-on-power refuelling, high neutron economy, and simple fuel design-make possible the realization of its potential fuel-cycle versatility. As resource constrains apply pressure on world markets, the feasibility of these options have become more attractive and closer to entering widespread commercial application

  15. HEAVY METALS AS UNWANTED COMPONENTS OF BACKWASH WATER DERIVED FROM GROUNDWATER TREATMENT

    Directory of Open Access Journals (Sweden)

    Robert Nowak

    2016-06-01

    Full Text Available The paper presents some aspects of the problem of heavy metals presence in wastewater and sewage sludge from water treatment. In the first part, issues on quality of wastewaters and sludge produced during water treatment along with actions aimed at the neutralization of such wastes, were discussed. Subsequent parts of the work present the example of 12 groundwater treatment stations in a particular municipality, and the problem of backwash water quality, in particular, heavy metals contents. The analysis covered a period of three years: 2013, 2014, and 2015. The authors, using the discussed examples, have shown that besides hydrated iron and manganese oxides, also other toxic contaminants can be present in backwash water from groundwater treatment. In particular, the qualitative analysis of the backwash water revealed the presence of heavy metals, mainly zinc. The test results for backwash water were compared with those of filtrate qualitative assessment, wherein the heavy metals were not found. This fact indicated the metal retention in the filter bed and their unsustainable immobilization resulting in penetration of heavy metals from deposit to the backwash water along with other impurities, mainly iron and manganese oxides. The main conclusion from the study is to demonstrate the need for constant monitoring of the backwash water quality, including the presence of toxic heavy metals. This is also important because of the requirement to minimize the negative environmental impact of wastes generated during the water treatment process.

  16. Utilization of plants for stabilization and cleaning up of metal contaminated soil and water

    Directory of Open Access Journals (Sweden)

    Miroslav Štofko

    2006-06-01

    Full Text Available Phytoremediation has been defined as the use of green plants and their associated rhizospheric microorganisms to remove, degrade, or contain contaminants located in soisl, sediments, groundwater, surface water, and even the atmosphere. Categories of phytoremediation include - phytoextraction or phytoaccumulation, phytotransformation, phytostimulation or plant-assisted bioremediation, phytovolatilization, rhizofiltration, pump and tree, phytostabilization, and hydraulic control. Phytoremediation of heavy metal contaminated soils basically includes phytostabilization, phytoextraction, rhizofiltration and phytovolatilization. Selection of plants for phytoremediation of metals depends on a particular application.

  17. Technologies for tritium control in fission reactors moderated with heavy water; Tecnologias para control de tritio en reactores de fision moderados con agua pesada

    Energy Technology Data Exchange (ETDEWEB)

    Ramilo, L B; Gomez de Soler, S M [Comision Nacional de Energia Atomica, San Martin (Argentina). Unidad de Actividad Reactores y Centrales Nucleares

    1997-12-31

    This study was done within a program one of whose objectives was to analyze the possible strategies and technologies, to be applied to HWR at Argentine nuclear power plants, for tritium control. The high contribution of tritium to the total dose has given rise to the need by the operators and/or designers to carry out developments and improvements to try to optimize tritium control technologies. Within a tritium control program, only that one which includes the heavy water detritiation will allow to reduce the tritium concentrations at optimum levels for safety and cost-effective power plant operation. The technology chosen to be applied should depend not only on the technical feasibility but also on the analysis of economic and juncture factors such as, among others, the quantity of heavy water to be treated. It is the authors` belief that AECL tendency concerning heavy water treatment in its future reactors would be to employ the CECE technology complemented with immobilization on titanium beds, with the `on-line` detritiation in each nuclear power plant. This would not be of immediate application since our analysis suggests that AECL would assume that the process is under development and needs to be tested. (author). 21 refs.

  18. "Periodic-table-style" paper device for monitoring heavy metals in water.

    Science.gov (United States)

    Li, Miaosi; Cao, Rong; Nilghaz, Azadeh; Guan, Liyun; Zhang, Xiwang; Shen, Wei

    2015-03-03

    If a paper-based analytical device (μ-PAD) could be made by printing indicators for detection of heavy metals in chemical symbols of the metals in a style of the periodic table of elements, it could be possible for such μ-PAD to report the presence and the safety level of heavy metal ions in water simultaneously and by text message. This device would be able to provide easy solutions to field-based monitoring of heavy metals in industrial wastewater discharges and in irrigating and drinking water. Text-reporting could promptly inform even nonprofessional users of the water quality. This work presents a proof of concept study of this idea. Cu(II), Ni(II), and Cr(VI) were chosen to demonstrate the feasibility, specificity, and reliability of paper-based text-reporting devices for monitoring heavy metals in water.

  19. Heavy metal atmospheric emissions from coal-fired power plants - Assessment and uncertainties

    International Nuclear Information System (INIS)

    Lecuyer, I.; Ungar, A.; Peter, H.; Karl, U.

    2004-01-01

    Power generation using fossil fuel combustion (coal and fuel-oil) participates, with other sectors, to heavy metal atmospheric emissions. The dispersion of these hazardous pollutants throughout the environment is more and more regulated. In order to assess the annual flows emitted from EDF coal-fired power plants, a computerized tool has been developed, based on the methodology defined by IFARE/DFIU in 1997. The heavy metal partition factors within the plant unit are determined according to the type of unit and the coal characteristics. Heavy metals output flows, and especially those emitted with flue gas at the stack, are then deduced from the actual coal consumption and chemical composition. A first inventory of heavy metal emissions from EDF coal-fired power plants has been achieved for year 2001. Values are accurate (± 40 %) for nonvolatile elements (Cr, Cu, Co, Mn, Ni, V) and for PM 10 and PM 2.5 (particulate matter below 10 μm and 2.5 μm). The uncertainty is higher (± 80 %) for volatile elements (As, Pb, Zn). Excess indicative values are given for elements which are both volatile and at low concentrations in coal (Hg, Se, Cd). (author)

  20. Thermal neutron standard fields with the KUR heavy water facility

    International Nuclear Information System (INIS)

    Kanda, K.; Kobayashi, K.; Shibata, T.

    1978-01-01

    A heavy water facility attached to the KUR (Kyoto University Reactor, swimming pool type, 5 MW) yields pure thermal neutrons in the Maxwellian distribution. The facility is faced to the core of KUR and it contains about 2 tons of heavy water. The thickness of the layer is about 140 cm. The neutron spectrum was measured with the time of flight technique using a fast chopper. The measured spectrum was in good agreement with the Maxwellian distribution in all energy region for thermal neutrons. The neutron temperature was slightly higher than the heavy water temperature. The contamination of epithermal and fast neutrons caused by photo-neutrons of the γ-n reaction of heavy water was very small. The maximum intensity of thermal neutrons is 3x10 11 n/cm 2 sec. When the bismuth scatterer is attached, the gamma rays contamination is eliminated by the ratio of 0.05 of gamma rays to neutrons in rem. This standard neutron field has been used for such experiments as thermal neutron cross section measurement, detector calibration, activation analysis, biomedical purposes etc. (author)

  1. Bacterial mediated alleviation of heavy metal stress and decreased accumulation of metals in plant tissues: Mechanisms and future prospects.

    Science.gov (United States)

    Etesami, Hassan

    2018-01-01

    Heavy metal pollution of agricultural soils is one of main concerns causing some of the different ecological and environmental problems. Excess accumulation of these metals in soil has changed microbial community (e.g., structure, function, and diversity), deteriorated soil, decreased the growth and yield of plant, and entered into the food chain. Plants' tolerance to heavy metal stress needs to be improved in order to allow growth of crops with minimum or no accumulation of heavy metals in edible parts of plant that satisfy safe food demands for the world's rapidly increasing population. It is well known that PGPRs (plant growth-promoting rhizobacteria) enhance crop productivity and plant resistance to heavy metal stress. Many recent reports describe the application of heavy metal resistant-PGPRs to enhance agricultural yields without accumulation of metal in plant tissues. This review provides information about the mechanisms possessed by heavy metal resistant-PGPRs that ameliorate heavy metal stress to plants and decrease the accumulation of these metals in plant, and finally gives some perspectives for research on these bacteria in agriculture in the future. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Computational modeling and analysis of heavy water losses in boiler blow down with different positions of BBW-V100 at KANUPP

    International Nuclear Information System (INIS)

    Maqbool, M. U.

    2012-01-01

    The term blowdown is referred to the boilers and steam generators. Blowing down water from the steam generators maintains the chemistry of the feedwater and helps prevent scaling or sludge formation. In a nuclear power plant, the primary loop contains some activity in the form of tritium content. In boilers, primary and secondary systems interface and due to the pressure difference there is always a chance of mixing of primary and secondary fluids in event of tube leak. This primary fluid i.e., heavy water in our case can be lost through the blowdown lines after mixing with the feedwater. This thesis is a computational work for the determination of heavy water losses through the blowdown lines. (author)

  3. Heavy metals effects on forage crops yields and estimation of elements accumulation in plants as affected by soil

    International Nuclear Information System (INIS)

    Grytsyuk, N.; Arapis, G.; Perepelyatnikova, L.; Ivanova, T.; Vynograds'ka, V.

    2006-01-01

    Heavy metals (Cu, Cd, Pb, Zn) effect on the productivity of forage crops (clover and perennial cereal grasses) and their accumulation in plants, depending on the concentration of these elements in a soil, has been studied in micro-field experiments on three types of soil. The principle objective was to determine regularities of heavy metals migration in a soil-plant system aiming the estimation of permissible levels of heavy metals content in soils with the following elaboration of methods, which regulate the toxicants transfer to plants. Methods of field experiments, agrochemical and atomic absorption analysis were used. Results were statistically treated by Statistica 6.0, S-Plus 6. Experimental results have shown that the intensity of heavy metals accumulation in plants depends on the type of the soil, the species of plants, the physicochemical properties of heavy metals and their content in the soil. Logarithmic interdependency of heavy metals concentration in soils and their accumulation in plants is suggested. However, the strong correlation between the different heavy metals concentrations in the various soils and the yield of crops was not observed. Toxicants accumulation in crops decreased in time

  4. Heavy metals effects on forage crops yields and estimation of elements accumulation in plants as affected by soil.

    Science.gov (United States)

    Grytsyuk, N; Arapis, G; Perepelyatnikova, L; Ivanova, T; Vynograds'ka, V

    2006-02-01

    Heavy metals (Cu, Cd, Pb, Zn) effect on the productivity of forage crops (clover and perennial cereal grasses) and their accumulation in plants, depending on the concentration of these elements in a soil, has been studied in micro-field experiments on three types of soil. The principle objective was to determine regularities of heavy metals migration in a soil-plant system aiming the estimation of permissible levels of heavy metals content in soils with the following elaboration of methods, which regulate the toxicants transfer to plants. Methods of field experiments, agrochemical and atomic absorption analysis were used. Results were statistically treated by Statistica 6.0, S-Plus 6. Experimental results have shown that the intensity of heavy metals accumulation in plants depends on the type of the soil, the species of plants, the physicochemical properties of heavy metals and their content in the soil. Logarithmic interdependency of heavy metals concentration in soils and their accumulation in plants is suggested. However, the strong correlation between the different heavy metals concentrations in the various soils and the yield of crops was not observed. Toxicants accumulation in crops decreased in time.

  5. Heat exchangers in heavy water reactor systems

    International Nuclear Information System (INIS)

    Mehta, S.K.

    1988-01-01

    Important features of some major heat exchange components of pressurized heavy water reactors and DHRUVA research reactor are presented. Design considerations and nuclear service classifications are discussed

  6. Environmental assessment of ground water pollution by heavy ...

    African Journals Online (AJOL)

    The aim of this study was to investigate the relationship between the concentrations of heavy metals in well water and bioaccumulation of the most abundant metals in chicken tissues in some areas in the province of Mecca Almokaramah, Saudi Arabia. Among the heavy metals (Cd, Zn, Cr, Mn, Cu Hg, Pb and Ni) studied, ...

  7. The use of heavy metal accumulating plants for detoxication of chemically polluted soils

    Directory of Open Access Journals (Sweden)

    Jacek Antonkiewicz

    2004-01-01

    Full Text Available The studies conducted from 1997 to 1999 in a vegetation hall were performed as a pot experiment on ordinary silt soil. Jerusalem artichoke, maize, Sida hermaphrodita Rusby, amaranth and hemp were used as indicator plants. The results confirmed, great diversification of the element contents which depends not only on the species but also on the part of individual plants. Analysis of the data revealed also another dependence: increased concentration of heavy metals in the soil corresponded to a higher content of heavy metals in the plants. Significant differences in this respect were observed for the plant species grown in unpolluted or differently contaminated soil.

  8. Regulating specific organic substances and heavy metals in industrial wastewater discharged to municipal wastewater treatment plants

    DEFF Research Database (Denmark)

    Grüttner, Henrik; Munk, L.; Pedersen, F.

    1994-01-01

    Due to the extension of wastewater treatment plants to nutrient removal and the development towards reuse of sludge m agriculture, new guidelines for regulating industrial discharges m Denmark were needed. The paper describes how a concept for regulating the discharge of specific organic substances...... substances, present knowledge of fate and effects in biological treatment plants is too scarce to underpin the setting of general standards. Therefore, it has been decided to base the developed priority system on the data used in the EEC-system for classification of hazardous chemicals. This includes ready...... degradability, defined by the OECD-test, bio-sorption and bio-accumulation, defined by the octanol/water distribution coefficient and toxic effects on water organisms. Several potential effects of seven heavy metals have been evaluated, and the most critical effects were found to be the quality criteria...

  9. Heavy metal partitioning of suspended particulate matter-water and sediment-water in the Yangtze Estuary.

    Science.gov (United States)

    Feng, Chenghong; Guo, Xiaoyu; Yin, Su; Tian, Chenhao; Li, Yangyang; Shen, Zhenyao

    2017-10-01

    The partitioning of ten heavy metals (As, Cd, Co, Cr, Cu, Hg, Ni, Pb, Sb, and Zn) between the water, suspended particulate matter (SPM), and sediments in seven channel sections during three hydrologic seasons in the Yangtze Estuary was comprehensively investigated. Special attention was paid to the role of tides, influential factors (concentrations of SPM and dissolved organic carbon, and particle size), and heavy metal speciation. The SPM-water and sediment-water partition coefficients (K p ) of the heavy metals exhibited similar changes along the channel sections, though the former were larger throughout the estuary. Because of the higher salinity, the K p values of most of the metals were higher in the north branch than in the south branch. The K p values of Cd, Co, and As generally decreased from the wet season to the dry season. Both the diagonal line method and paired samples t-test showed that no specific phase transfer of heavy metals existed during the flood and ebb tides, but the sediment-water K p was more concentrated for the diagonal line method, owing to the relatively smaller tidal influences on the sediment. The partition coefficients (especially the K p for SPM-water) had negative correlations with the dissolved organic carbon (DOC) but positive correlations were noted with the particle size for most of the heavy metals in sediment. Two types of significant correlations were observed between K p and metal speciation (i.e., exchangeable, carbonate, reducible, organic, and residual fractions), which can be used to identify the dominant phase-partition mechanisms (e.g., adsorption or desorption) of heavy metals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Removal of Heavy Metals from Leachate Using Electro-Assisted Phytoremediation (EAPR and Up-Take by Water Hyacinth (Eichornia crassipes

    Directory of Open Access Journals (Sweden)

    Rudy Syah Putra

    2018-05-01

    Full Text Available The garbage disposal management using landfill system produces an unpleasant odor of wastewater (i.e. leachate which can disrupt the groundwater equilibrium in the rainy season. The combination of electro-assisted and phytoremediation which is hereinafter referred as Electro-Assisted Phytoremediation (EAPR for removal of heavy metals from leachate has been demonstrated in a laboratory-scale experiment. A batch reactor setting was used to evaluate the potential removal and uptake of heavy metals (Fe, Cu, Cd, and Pb concentration by water hyacinth (Eichornia crassipes in the aquatic environment. An EAPR system was carried out for 11 d using constant voltage of 2 V. The results showed that the heavy metals concentration in the leachate decreased significantly for Cu, Fe, Cd and Pb metals from their initial concentration. The EAPR process could reduce as much as 77.8, 22, 31.6 and 30.0%, respectively for Fe, Cu, Cd, and Pb. Decreasing of heavy metals was followed by decreasing of TDS, electrical conductivity but increased DO concentration. Chlorophyll content in a treated plant with EAPR system showed that the water hyacinth could cope with the stress condition meanwhile accumulated high heavy metal concentration from the leachate.

  11. Change of deuterium volume content in heavy water during carbon dioxide dissolution in it

    International Nuclear Information System (INIS)

    Efimova, T.I.; Kapitanov, V.F.; Levchenko, G.V.

    1985-01-01

    Carbon dioxide solution density in heavy water at increased temperature and pressure is measured and the influence of carbon dioxide solubility in heavy water on volumetric content of deuterium in it is determined. Investigations were conducted in the temperature range of 303-473 K and pressure range of 3-20 MPa by the autoclave method. Volumetric content of deuterium in heavy water decreases sufficiently with CO 2 dissolved in it in comparison with pure D 2 O under the similar conditions, and this decrease becomes more sufficient with the pressure increase. With the temperature increase the volumetric content of deuterium both for heavy water and for saturated carbon solution in heavy water decreases

  12. Oil flow in deep waters: comparative study between light oils and heavy oils

    Energy Technology Data Exchange (ETDEWEB)

    Andreolli, Ivanilto [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2009-12-19

    Ultra deeper waters fields are being exploited due to technological development. Under this scenario, the flow design is accomplished through pipelines subjected to low temperature and high pressure. Moreover, these flow lines are usually long causing a fast fluid cooling, which may affect flow assurance in some cases. Problems during topsides production plant's restart might occur if the oil is viscous and even in steady state a significant different behavior can be noticed, if compared to a less viscous oil. A comparison between light and heavy oil through a case study with the objective to show some heavy oil flow particularities is the purpose of this paper. Permanent and transient analyses for a specific geometry are presented. The results showed that thermal and proper viscosity modeling are required for heavy oil flow, differently from that of light oil flow, due to the exponential viscosity dependence to temperature and because the predominant laminar regime. In addition, on heavier and heavier oil flow systems, it is essential to consider exportation system's restart. (author)

  13. Determination of the Content of Heavy Metals in Pyrite Contaminated Soil and Plants

    Directory of Open Access Journals (Sweden)

    Miroslava Marić

    2008-09-01

    Full Text Available Determination of a pyrite contaminated soil texture, content of heavy metals in the soil and soil pH, was the aim in the investigation. Acidification of damaged soil was corrected by calcium carbonate. Mineral nutrients and organic matter (NPK, dung, earthworm cast, straw and coal dust were added to damaged soil. Afterwards, the soil was used for oat production. Determination of total heavy metal contents (Cu, Pb, Zn, Fe in soil was performed by atomic absorption spectrofotometry. Plant material (stems, seeds was analysed, too. Total concentration of the heavy metals in the plant material were greater than in crop obtained in unaffected soil.

  14. Heavy metals content in plant-growing products as the results of agroecological monitoring

    International Nuclear Information System (INIS)

    Kuznetsov, A.V.; Lunev, M.I.; Pavlikhina, A.V.; Lobas, N.V.

    2008-01-01

    The generalised data on the heavy metals and arsenic contents in grain and vegetable cultures, green mass and hay of various grasses are presented. The dependence of heavy metal accumulation factors in plant-growing products on soil properties is shown. The estimation of levels of the heavy metals contents in accordance with the admissible content standards is given.

  15. Removal of gadolinium nitrate from heavy water

    Energy Technology Data Exchange (ETDEWEB)

    Wilde, E.W.

    2000-03-22

    Work was conducted to develop a cost-effective process to purify 181 55-gallon drums containing spent heavy water moderator (D2O) contaminated with high concentrations of gadolinium nitrate, a chemical used as a neutron poison during former nuclear reactor operations at the Savannah River Site (SRS). These drums also contain low level radioactive contamination, including tritium, which complicates treatment options. Presently, the drums of degraded moderator are being stored on site. It was suggested that a process utilizing biological mechanisms could potentially lower the total cost of heavy water purification by allowing the use of smaller equipment with less product loss and a reduction in the quantity of secondary waste materials produced by the current baseline process (ion exchange).

  16. Selected bibliography on deuterium isotope effects and heavy water

    International Nuclear Information System (INIS)

    Dave, S.M.; Donde, M.M.

    1983-01-01

    In recent years, there has been a great deal of interest in using deuterium and heavy water not only in nuclear industry but also in various fields of basic as well as applied research in physics, chemistry and biology. As a result, the literature is being enriched with a large number of research papers and technical reports published each year. Thus, to enable the scientists to have an easy reference to these works, an endeavour has been made in this selected bibliography, to enlist the publications related to these fields. Since the interest is concerned mainly with heavy water production processes, deuterium isotope effects etc., several aspects (e.g. nuclear) of deuterium have not been covered here. The material in this bibliography which cites 2388 references has been classified under six broad headings, viz. (1) Production of heavy water, (2) Study of deuterium isotope effects, (3) Analysis and Properties of heavy water, (4) Laser Separation of deuterium, (5) Isotopic exchange reactions, and (6) Miscellaneous. The sources of information used for this compilation are chemical abstracts, nuclear science abstracts, INIS Atomindex and also some scattered search through journals and reports available in the B.A.R.C. library. However, in spite of sincere attempts for a wide coverage, no claim is being made towards the exhaustiveness of this bibliography. (author)

  17. Phytoextraction of heavy metal from sewage sludge by plants

    Directory of Open Access Journals (Sweden)

    Jaroslava Bartlová

    2010-01-01

    Full Text Available In 2008 and 2009, studies made contents of cadmium and lead in the soil and their uptake by non-traditional plants were studied in a small-plot trial. At the same time also the effect of bio-algeen preparations on phytoextraction of heavy metals by these plants was investigated. Experimental plots were established on the reclaimed land after closing down mining operations in the town of Žacléř (North-East Bohemia where a layer of sewage sludge from a wastewater treatment plant 0.6–0.8 m thick was subsequently applied. The locality is situated in the altitude of 612 m, its average annual temperature is about 6.8 °C and the mean annual precipitations are 857 mm. Analyses revealed higher concentrations of heavy metals in the applied sewage sludge. The average concentrations of lead and cadmium were 180 mg . kg−1 and 6.89 mg . kg−1, respectively. The experiment had two variants: Variant 1 – sewage sludge without any other substances, and Variant 2 – sewage sludge + bio-algeen preparations (B. A. S-90 or B. A. Root Concentrate. To find the most suitable plant species for the phytoextraction of cadmium and lead, the following non-traditional plants were cultivated in both variants: fodder mallow (Malva verticillata L., rye (Secale cereale L. var. multicaule METZG. ex ALEF. and white sweet clover (Melilotus alba MEDIC.. The highest accumulation of cadmium and lead in the aboveground biomass was found out in rye, viz 14.89 mg . kg−1 DM and 14.89 mg . kg−1 DM of Cd and Pb, respectively., As compared with other plants under study, white sweet clover exhibited the significantly lowest capability to extract both heavy metals from soil (viz 0.22 and 3.20 mg . kg−1 DM of Cd and Pb, respectively. A positive effect of bio-algeen on phytoextraction of cadmium and lead was evident in all plants. The highest yield of aboveground biomass was recorded on the plot with white sweet clover with added

  18. Technical solutions for tritium removal from Cernavoda NPP heavy water systems

    International Nuclear Information System (INIS)

    Barariu, Gheorghe; Panait, Adrian

    2002-01-01

    In CANDU nuclear plants 2400 KCi/GW(e) - year tritium is generated. At a CANDU - 600 reactor similar to Cernavoda NPP Unit 1, 1500 KCi/year of tritium is generated 95% being in the D 2 O moderator, which can achieve a radioactivity level of 80 - 100 Ci/kg. Tritium in heavy water contributes with 30 - 50% to the doses received by operation personnel and with 20% to the radioactivity released to the environment. The extraction of tritium heavy water at CANDU reactors implies the following possibilities: - the radioactivity level reduction in the operation area; - the maintenance and repair cost reduction due to reduction of personnel protection measures and increased labor productivity; - the increase of NPP utilization factor by shutdown time reduction for maintenance and repair; - tritium concentration reduction from technological systems, ensuring thus the possibility of redesigning the systems in order to lower the cost of investment; - profitable use of extracted tritium. Technical measures provided by AECL project for CANDU 600 at Cernavoda make possible to satisfy the current standards concerning tritium concentration in the operation area atmosphere of 5 x 10 -6 Ci/m 3 . The regulations recommend that the radioactivity level should be maintained as low as possible in conformity with ALARA principles. Also, it is possible that norms will become more restrictive in the future, so the tritium removal technology is a good preventive measure which may become very necessary. The methods, which currently reached the industrial or pilot stages, are based on catalyzed chemical exchange, the heavy water electrolysis, and deuterium distillation. They are known as: VPCE - Vapour Phase Catalytic Exchange; LPCE - Liquid Phase Catalytic Exchange; DE - Direct Electrolysis; CD - Cryogenic Distillation. As transfer processes the catalyzed chemical exchange and heavy water electrolysis are used while concentration of tritium gas is done by cryogenic distillation. At present the

  19. Expressing a bacterial mercuric ion binding protein in plant for phytoremediation of heavy metals.

    Science.gov (United States)

    Hsieh, Ju-Liang; Chen, Ching-Yi; Chiu, Meng-Hsuen; Chein, Mei-Fang; Chang, Jo-Shu; Endo, Ginro; Huang, Chieh-Chen

    2009-01-30

    A specific mercuric ion binding protein (MerP) originating from transposon TnMERI1 of Bacillus megaterium strain MB1 isolated from Minamata Bay displayed good adsorption capability for a variety of heavy metals. In this study, the Gram-positive MerP protein was expressed in transgenic Arabidopsis to create a model system for phytoremediation of heavy metals. Under control of an actin promoter, the transgenic Arabidpsis showed higher tolerance and accumulation capacity for mercury, cadium and lead when compared with the control plant. Results from confocal microscopy analysis also indicate that MerP was localized at the cell membrane and vesicles of plant cells. The developed transgenic plants possessing excellent metal-accumulative ability could have potential applications in decontamination of heavy metals.

  20. Ion-Exchange Treating of Cyanide-Contained Waste Water of Some Hydrometallurgy Plants

    International Nuclear Information System (INIS)

    Scheglov, M.Y.

    1999-01-01

    The paper presents results of investigation of possibility to apply strong base anionite for treating waste water of a hydrometallurgical plant from cyanide compounds of heavy metals and to utilize value component (Au, Cu, Zn and so on). As an object of the investigation thickener outlets of a processing plant were chosen. Sorption researches were carried out with model solutions allied to the thickener outlet and with the thickener outlets too in static and dynamic conditions. The main technological parameters were determined, technological schemes of value component sorption and ignite regeneration were developed

  1. Extraction of deuterium from D-rich process condensate of ammonia plants

    Energy Technology Data Exchange (ETDEWEB)

    Haldar, T K; Kumar, Manoj; Ramamurty, C B [Heavy Water Board, Department of Atomic Energy, Mumbai (India)

    1994-06-01

    Heavy water plants based on ammonia-hydrogen exchange process receives feed synthesis gas from the adjacent fertilizer plants. The production capacity of such heavy water plants is directly proportional to the deuterium-content in feed synthesis gas. The chemical process involved in gas generation section of the fertilizer plant includes catalytic steam-reforming of natural gas/naphtha/fuel oil followed by shift conversion, alternatively coal classification followed by shift conversion. Effective extraction of deuterium from the deuterium-rich process condensate can boost the production capacity of heavy water plants considerably. This paper discusses various possible methods to achieve this objective. (author). 5 refs., 1 fig., 1 tab.

  2. Reuse of Ablution Water to Improve Peat Soil Characteristics for Ornamental Landscape Plants Cultivation

    Directory of Open Access Journals (Sweden)

    Radin Mohamed Radin Maya Saphira

    2017-01-01

    Full Text Available The present study aimed to reuse of ablution water for washing peat soil in order to reduce the concentrations of heavy metals in these soils which might effect negatively on the plant growth. The washing process design was similar to horizontal subsurface flow constructed wetlands (HSSFCW consist of layers of peat and sand soil and surrounded by gravel on both sides. Strelitzia sp. was used to detect the presence negative effect of the washing process on the morphological characteristics of the plants. The physical and chemical characteristics of ablution water was examined before and after the washing process by using Inductively Couple Plasma- Mass Spectrometer (ICP-MS Atomic Absorption Spectrometer (AAS. The characteristics of peat soil before and after the washing process were examined by using X-Ray Fluorescence (XRF. The results revealed that the percentage of FeO3in peat soil reduced from 45.80 to 1.01%. The percentage of SiO2 in sand soil dropped from 87.7 to 67.10%. Parameters of ablution water resulted from the washing process which including Biological Oxygen Demand (BOD5 and heavy metals have increased but still within the standard limits for the disposal of ablution water into the environment. No atrophy was observed in Strelitzia sp. leaves, indicating the ability of plant to grow normally. It can be concluded that the utilization of ablution water in the washing of peat soil has improve the characteristics of the soil without effect on their organic constitutes.

  3. Reactivity margins in heavy water moderated production reactors

    International Nuclear Information System (INIS)

    Benton, F.D.

    1981-11-01

    The design of the reactor core and components of the heavy water moderated reactors at the Savannah River Plant (SFP) can be varied to produce a number of isotopes. For the past decade, the predominant reactor core design has been the enriched-depleted lattice. In this lattice, fuel assemblies of highly enriched uranium and target assemblies of depleted uranium, which produce plutonium, occupy alternate lattice positions. This heterogeneous lattice arrangement and a nonuniform control rod distribution result in a reactor core that requires sophisticated calculational methods for accurate reactivity margin and power distribution predictions. For maximum accuracy, techniques must exist to provide a base of observed data for the calculations. Frequent enriched-depleted lattice design changes are required as product demands vary. These changes provided incentive for the development of techniques to combine the results of calculations and observed reactivity data to accurately and conveniently monitor reactivity margins during operation

  4. Neutrinos: Heavy water detector

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    The proponents of the Sudbury Neutrino Observatory (SNO) received a welcome Christmas present when William Winegard, Canadian Minister for Science and Technology announced the final details of the funding for this project, totalling 48 million Canadian dollars and including contributions from the US and the UK. The SNO experiment will extend significantly the study of solar neutrinos, using some 1,000 tonnes of heavy water to be installed more than two kilometres below ground in a nickel mine at Sudbury, Ontario

  5. Vegetation structure and heavy metal uptake by plants in the mining ...

    African Journals Online (AJOL)

    This study assessed the plant species composition and the heavy metal uptake by plants in the mining-impacted and non mining-impacted areas of the southern Lake Victoria basin. The vegetation of the wetlands was stratified into riverine forest, riverine thickets, swampy grassland, open woodland and floodplain grassland ...

  6. Contents of some heavy metals in plants from Saginaw Bay (Lake Huron) and some small lakes in wilderness areas of Michigan's Upper Peninsula as analyzed by neutron activation analysis

    International Nuclear Information System (INIS)

    Wells, J.R.; Kaufman, P.B.; Jones, J.D.; Estabrook, G.F.; Ghosheh, N.S.; Michigan Univ., Ann Arbor; Eastern Michigan University, Ypsilanti

    1982-01-01

    The highest concentrations of heavy metals occured in plants collected near the mouth of the Saginaw River. The alga, Cladophora sp., and the flowering plant, Typha augustifolia (cat-tail), are notable for the high concentration of heavy metals. In addition, several other species that were sampled from small lakes in Michigan's Upper Peninsula contained higher concentrations of certain metals (Ba, Cr, Rb) than from any samples obtained from Saginaw Bay. Different organs of the same species, or of the same plant, such as cut-tail, vary widely in concentrations of the same element. A computer-derived analysis of our data is presented, and the implications of our results as they relate to pollution by heavy metals in fresh-water lakes is discussed. (author)

  7. Accumulation of Heavy Metals in Soil and Kiwifruit of Planting Base in Western Hunan Province, China

    Directory of Open Access Journals (Sweden)

    WANG Ren-cai

    2017-05-01

    Full Text Available The heavy metals accumulation in soil and kiwi fruit plant in Western Hunan Province main kiwifruit planting base were analyzed, such as As, Pb, Hg, Cd, Cr. The results showed that the accumulation of heavy metals in soil of 6 kiwifruit planting areas were not obvious. The contents of heavy metals in most of areas of Western Hunan Province were below the national standard, except one area where the soil contents of cadmium (4.900 mg·kg-1, mercury (0.634 mg·kg-1were exceeded. At the same time, the comprehensive pollution index of heavy metals was less than 0.7 in these areas. There were 5 bases with no pollution of heavy metal, all which the kiwifruit could be safely produced in line with the requirements of the green kiwifruit planting base soil standards. At these areas, the contents of various heavy metals(except cadmium and mercurywere small in the branches and leaves of kiwifruit; kiwifruit had a very well capacity to absorb the cadmium when the cadmium content of its branches reached 12.73%. The heavy metal contents of the kiwifruit in the 6 regions, which belonging to the pollutionfree green fruits, were below or far lower than the national standard. According to the comprehensive analysis, the soil condition of the main cultivated land in Western Hunan Province was good, and the fruit had no heavy metal residues.

  8. Conceptual design of a quasi-homogeneous pressurized heavy water reactor to be operated in the closed Th-U233 fuel cycle

    International Nuclear Information System (INIS)

    1979-06-01

    This paper deals with the heavy water reactor, which, from the neutron economy point of view, offers advantages over the light water reactor. Its capability to be fuelled with natural uranium has also been considered a desirable nuclear option by various countries with sufficient domestic uranium resources not wishing to be dependent on the import of enrichment and other fuel cycle services which, in addition, would draw on the foreign exchange reserves. Pressurized heavy water reactors have been designed and built according to two somewhat different versions. While the Canadian CANDU-PHWR concept uses pressure tubes in a nearly unpressurized moderator tank (calandria), the German development line takes advantage of the established and well proven LWR technology, and, thus, uses a pressure vessel design where coolant channels and the surrounding moderator are held at equal pressure. This pressure vessel type heavy water reactor which has been built on a commercial demonstration plant level at ATUCHA in Argentina is described in a companion paper where also a conceptual design for a 685 MWsub(e) PHWR is discussed

  9. [Effect of Recycled Water Irrieation on Heavy Metal Pollution in Irrigation Soil].

    Science.gov (United States)

    Zhou, Yi-qi; Liu, Yun-xia; Fu, Hui-min

    2016-01-15

    With acceleration of urbanization, water shortages will become a serious problem. Usage of reclaimed water for flushing and watering of the green areas will be common in the future. To study the heavy metal contamination of soils after green area irrigation using recycled wastewater from special industries, we selected sewage and laboratory wastewater as water source for integrated oxidation ditch treatment, and the effluent was used as irrigation water of the green area. The irrigation units included broad-leaved forest, bush and lawn. Six samples sites were selected, and 0-20 cm soil of them were collected. Analysis of the heavy metals including Cr, Mn, Ni, Cu, Zn, As, Cd and Pb in the soil showed no significant differences with heavy metals concentration in soil irrigated with tap water. The heavy metals in the soil irrigated with recycled water were mainly enriched in the surface layer, among which the contents of Cr, Ni, Cu, Zn and Pb were below the soil background values of Beijing. A slight pollution of As and Cd was found in the soil irrigated by recycled water, which needs to be noticed.

  10. Investigation of the heavy water distillation system at the RA reactor

    International Nuclear Information System (INIS)

    Zecevic, V.; Badrljica, R.

    1963-01-01

    The heavy water distillation system was tested because this was not done before the reactor start-up. Detailed inspection of the system components showed satisfactory results. Leak testing was done as well as the testing of the instrumentation which enables reliable performance of the system. Performance testing was done with ordinary water and later 2700 l of heavy water from the reactor was purified, decreasing the activity by 45%

  11. Increased heavy metal tolerance of cowpea plants by dual ...

    African Journals Online (AJOL)

    Through biological inoculation technology, the bacterial-mycorrhizal-legume tripartite symbiosis in artificially heavy metal polluted soil was documented and the effects of dual inoculation with arbuscular mycorrhizal (AM) fungus and Rhizobium (N-fixing bacteria, NFB) on the host plant cowpea (Vigna sinensis) in pot ...

  12. Heavy metal levels in commonly used traditional medicinal plants

    International Nuclear Information System (INIS)

    Said, S.; Zahir, E.

    2010-01-01

    In the present study a survey of 24 commonly used medicinal plants of Indian subcontinent origin was carried out to evaluate their levels of heavy metals by electrothermal atomic absorption spectroscopy. The results showed that the highest mean value for Cd (12.06 mu g.g/sup -1/), Cr (24.50 mu g.g/sup -1/), Cu (15.27 mu g.g/sup -1/), Pb (1.30 mu g.g/sup -1/), Fe (885.60 mu g.g/sup -1/), Mn (90.60 mu g.g/sup -1/), Ni (9.99 mu g.g/sup -1/) and Zn (77.15 mu g.g/sup -1/) were found in Lawsonia inermis, Murraya koenigii, Mentha spicata, Beta vulgaris Linn, Mentha spicata, Lagenaria sicerana standl, Lawsonia inermis, Emblica officinalis, respectively. The mean and maximum levels of Cd in plant samples were found higher than the recommended values of the Joint Expert Committee on Food Additives of the Food and Agriculture Organization of the United Nations and the World Health Organization and may constitute a health hazard for consumers. All other heavy metals in medicinal plants were found below the recommended tolerable limits. (author)

  13. Heavy metal contamination of soil and water in the vicinity of an abandoned e-waste recycling site: implications for dissemination of heavy metals.

    Science.gov (United States)

    Wu, Qihang; Leung, Jonathan Y S; Geng, Xinhua; Chen, Shejun; Huang, Xuexia; Li, Haiyan; Huang, Zhuying; Zhu, Libin; Chen, Jiahao; Lu, Yayin

    2015-02-15

    Illegal e-waste recycling activity has caused heavy metal pollution in many developing countries, including China. In recent years, the Chinese government has strengthened enforcement to impede such activity; however, the heavy metals remaining in the abandoned e-waste recycling site can still pose ecological risk. The present study aimed to investigate the concentrations of heavy metals in soil and water in the vicinity of an abandoned e-waste recycling site in Longtang, South China. Results showed that the surface soil of the former burning and acid-leaching sites was still heavily contaminated with Cd (>0.39 mg kg(-1)) and Cu (>1981 mg kg(-1)), which exceeded their respective guideline levels. The concentration of heavy metals generally decreased with depth in both burning site and paddy field, which is related to the elevated pH and reduced TOM along the depth gradient. The pond water was seriously acidified and contaminated with heavy metals, while the well water was slightly contaminated since heavy metals were mostly retained in the surface soil. The use of pond water for irrigation resulted in considerable heavy metal contamination in the paddy soil. Compared with previous studies, the reduced heavy metal concentrations in the surface soil imply that heavy metals were transported to the other areas, such as pond. Therefore, immediate remediation of the contaminated soil and water is necessary to prevent dissemination of heavy metals and potential ecological disaster. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. The Assessment of Water Treatment Plant Sludge Properties and the Feasibility of Its Re-use according to Environmental Standards: Shahid Beheshti Water Treatment Plant Case Study, Hamadan

    Directory of Open Access Journals (Sweden)

    H. Pourmand

    2016-04-01

    Full Text Available Introduction & Objectives: Water treatment leads to produce large volumes of sludges in water treatment plants which are considered as solid waste, and should be managed appropriately and logically to avoid bioenvironmental effects. Materials & Methods: In this cross-sectional study, the required samples were taken from the sludge of Shahid Beheshti water treatment plant to assay physical and chemical characteristics during one year from summer, autumn and winter 93 until spring 94. Sampling and testing procedures were full fit according to standard methods. Results: The average concentration of total solids parameters (TSS, total suspended solids (TSS, and total dissolved solids (TDS were 22346, 21350 and 1005 mg/L, respectively. Among the heavy metals, aluminum, iron, manganese and zinc have the highest concentrations with the values of 1400, 956, 588 and 100 mg per kg of dry solids, respectively. The measured concentrations for cadmium were also higher than the permissible limits for agricultural purposes and discharges into the environment. The average concentrations of nickel were more than the recommended standard for industrial, agricultural and parkland application purposes. The concentrations were also slurry higher than the dry sludge. Conclusion: According to the past studies and results of this study, it could be concluded that contamination of heavy metals in sludge and slurry samples are more than dried sludge, .Therefore, if they are discharged into the environment, it is better to be disposed as dry sludges. Furthermore, because these types of waste sludges are routinely disposed in the environment, it is recommended to take the routine samples in order to measure the heavy metals and other relevant parameters contents of sludge before discharging it. (Sci J Hamadan Univ Med Sci 2016; 23 (1:57-64

  15. Experimental Study on Behavior of Bow-tie Tree Generation by Using Heavy Water

    Science.gov (United States)

    Kumazawa, Takao; Nakagawa, Wataru; Tsurumaru, Hidekazu

    Bow-tie tree (BTT) generated from contaminant, e.g., metal, carbon, amber(over cured resin) or void in insulator is a significant deterioration factor of XLPE power cable. However, essential role of water in generation and progress of BTT is not yet sufficiently cleared. In order to investigate the role of water we paid attention to difference in chemical properties of light water (H2O) and heavy water (D2O), moreover we evaluated influence of isotopic effect due to hydrogen and deuterium on behavior of BTT generation. In accelerated aging test the number of BTT in XLPE sample, in which copper powder of 500ppm was contaminated as BTT cores, dipped in heavy water (D2O:100wt%) decreased to one third compared with light water(D2O:0wt%). Furthermore, the maximum length of BTT decreased with increase in concentration of heavy water. The experimental results show that heavy water exerted a depression effect on generation and progress of BTT. We considered that the depression effect due to hydrogen isotope appeared by inhibiting ionization and elution of BTT cores, because salt-solubility and ionic mobility of heavy water are about 15 to 20% smaller than those of light water. Therefore, the essential role of water seemed to be production and transport of ions in XLPE.

  16. Heavy metal content of selected African leafy vegetables planted in ...

    African Journals Online (AJOL)

    Heavy metal content of selected African leafy vegetables planted in urban and peri-urban Nairobi, Kenya. ... African Journal of Environmental Science and Technology ... Government clean-up activities and monitoring of waste disposal is ...

  17. Ecotoxic heavy metals transformation by bacteria and fungi in aquatic ecosystem.

    Science.gov (United States)

    Chaturvedi, Amiy Dutt; Pal, Dharm; Penta, Santhosh; Kumar, Awanish

    2015-10-01

    Water is the most important and vital molecule of our planet and covers 75% of earth surface. But it is getting polluted due to high industrial growth. The heavy metals produced by industrial activities are recurrently added to it and considered as dangerous pollutants. Increasing concentration of toxic heavy metals (Pb(2+), Cd(2+), Hg(2+), Ni(2+)) in water is a severe threat for human. Heavy metal contaminated water is highly carcinogenic and poisonous at even relatively low concentrations. When they discharged in water bodies, they dissolve in the water and are distributed in the food chain. Bacteria and fungi are efficient microbes that frequently transform heavy metals and remove toxicity. The application of bacteria and fungi may offer cost benefit in water treatment plants for heavy metal transformation and directly related to public health and environmental safety issues. The heavy metals transformation rate in water is also dependent on the enzymatic capability of microorganisms. By transforming toxic heavy metals microbes sustain aquatic and terrestrial life. Therefore the application of microbiological biomass for heavy metal transformation and removal from aquatic ecosystem is highly significant and striking. This paper reviews the microbial transformation of heavy metal, microbe metal interaction and different approaches for microbial heavy metal remediation from water bodies.

  18. Method for heavy-water production by H2S--H2O chemical exchange process

    International Nuclear Information System (INIS)

    Strathdee, G.G.

    1978-01-01

    The invention discloses a heavy water production stage in a bithermal H 2 S gas H 2 O liquid exchange plant wherein the cold tower is operated under temperature and pressure conditions such that H 2 S in the liquid phase is formed and is maintained in the separation units (sieve trays or plates) of the cold tower. It has been found that the presence of liquid H 2 S acts as an efficient anti-foaming agent

  19. Elimination of radionuclides and heavy metals from soils

    International Nuclear Information System (INIS)

    Navarcik, I.; Cipakova, A.; Palagyl, S.

    1994-01-01

    Sorption and desorption of radionuclides and heavy metals, their vertical migration and gradual extraction from soils were studied. Tessier sequential extraction method was used for determination the physicochemical forms of radionuclides and heavy metals absorbed by root system of plants and leached into ground water. Fixed forms of heavy metals and radionuclides are prevailing in soils. As to artificial ( 90 Sr, 137 Cs) isotope ratio of fixed forms bound with soil components, it is higher for 137 Cs (black earth - 95%, sandy soil - 62%) as compared to 90 Sr. Mobilization procedures for elimination of unfavourable influence of these pollutants in soils were used. The bacteria Pseudomonas sp. and Micrococcus l. are applied for this purpose. At the same time the growing of technical plants (Linum usitatissimum L. and Brassica napus L. var.) was studied as a method for mobilizing the heavy metals and radionuclides from soils. Retardation influence of bacteria on 85 Sr was noticed after as much as 3 months. The sum of water-soluble and exchangeable fractions reached 60%. Values of Cs distribution proved that microorganisms or plants used had no appreciable influence on Cs-mobility. After 3 months the relative ratio of accessible fraction increased with about 5%. As to heavy metals, both bacteria and plant growing influenced their retardation. In the case of Cd, one month operation of microorganisms resulted in important increase of easily available Cd-ratio (about 25%) in soils. (author)

  20. Light and heavy water replacing system in reactor container

    International Nuclear Information System (INIS)

    Miyamoto, Keiji.

    1979-01-01

    Purpose: To enable to determine the strength of a reactor container while neglecting the outer atmospheric pressure upon evacuation, by evacuating the gap between the reactor container and a biological thermal shield, as well as the container simultaneously upon light water - heavy water replacement. Method: Upon replacing light water with heavy water by vacuum evaporation system in a nuclear reactor having a biological thermal shield surrounding the reactor container incorporating therein a reactor core by way of a heat expansion absorbing gap, the reactor container and the havy water recycling system, as well as the inside of heat expansion absorbing gap are evacuated simultaneously. This enables to neglect the outer atmospheric outer pressure upon evacuation in the determination of the container strength, and the thickness of the container can be decreased by so much as the external pressure neglected. (Moriyama, K.)

  1. Agroecological Responses of Heavy Metal Pollution with Special Emphasis on Soil Health and Plant Performances

    Directory of Open Access Journals (Sweden)

    Vaibhav Srivastava

    2017-10-01

    Full Text Available With modern day urbanization and industrialization, heavy metal (HM contamination has become a prime concern for today's society. The impacts of metal contamination on agriculture range from the agricultural soil to the produce in our food basket. The heavy metals (HMs and metalloids, including Cr, Mn, Co, Ni, Cu, Zn, Cd, Sn, Hg, Pb, among others, can result in significant toxic impacts. The intensification of agricultural land use and changes in farming practices along with technological advancement have led to heavy metal pollution in soil. Metals/metalloids concentrations in the soil are increasing at alarming rate and affect plant growth, food safety, and soil microflora. The biological and geological reorganization of heavy metal depends chiefly on green plants and their metabolism. Metal toxicity has direct effects to flora that forms an integral component of ecosystems. Altered biochemical, physiological, and metabolic processes are found in plants growing in regions of high metal pollution. However, metals like Cu, Mn, Co, Zn, and Cr are required in trace amounts by plants for their metabolic activities. The present review aims to catalog major published works related to heavy metal contamination in modern day agriculture, and draw a possible road map toward future research in this domain.

  2. The text of the agreement of 14 October 1981 between Argentina and the Agency for the application of Safeguards in relation to the heavy water production plant at Arroyito

    International Nuclear Information System (INIS)

    1995-01-01

    The Agreement between the Republic of Argentina, the Federative Republic of Brazil, the Brazilian-Argentine Agency for Accounting and Control of Nuclear Materials and the International Atomic Energy Agency for the Application of Safeguards came into force on 4 March 1994. As a result of the coming into force of the aforesaid Agreement for Argentina, the application of safeguards under the Agreement of 14 October 1981 between Argentina and the IAEA for the application of safeguards in relation to the heavy water production plant at Arroyito has been suspended

  3. IAEA activities in technology development for advanced water-cooled nuclear power plants

    International Nuclear Information System (INIS)

    Juhn, Poong Eil; Kupitz, Juergen; Cleveland, John; Lyon, Robert; Park, Je Won

    2003-01-01

    As part of its Nuclear Power Programme, the IAEA conducts activities that support international information exchange, co-operative research and technology assessments and advancements with the goal of improving the reliability, safety and economics of advanced water-cooled nuclear power plants. These activities are conducted based on the advice, and with the support, of the IAEA Department of Nuclear Energy's Technical Working Groups on Advanced Technologies for Light Water Reactors (LWRs) and Heavy Water Reactors (HWRs). Assessments of projected electricity generation costs for new nuclear plants have shown that design organizations are challenged to develop advanced designs with lower capital costs and short construction times, and sizes, including not only large evolutionary plants but also small and medium size plants, appropriate to grid capacity and owner financial investment capability. To achieve competitive costs, both proven means and new approaches should be implemented. The IAEA conducts activities in technology development that support achievement of improved economics of water-cooled nuclear power plants (NPPs). These include fostering information sharing and cooperative research in thermo-hydraulics code validation; examination of natural circulation phenomena, modelling and the reliability of passive systems that utilize natural circulation; establishment of a thermo-physical properties data base; improved inspection and diagnostic techniques for pressure tubes of HWRs; and collection and balanced reporting from recent construction and commissioning experiences with evolutionary water-cooled NPPs. The IAEA also periodically publishes Status Reports on global development of advanced designs. (author)

  4. Effect Of Heavy Metals Stress On Enzyme Activities And Chlorophyll Content Of Pea (Pisum Sativum) And Tomato Plants

    International Nuclear Information System (INIS)

    Ahmed, B.M.; El Maghrabi, G.; Hashem, M.F.

    2013-01-01

    The effects of heavy metal stress on the chlorophyll in addition to catalase and peroxidase activities were studied in the leaves and roots of tomato and pea plants. Four groups were studied; the control group and other three groups treated with heavy metals. Group 1HM was treated with 1.0 mg CuSO 4 /l + 0.2 mg CdSO 4 /l + 0.1 mg ZnNO 3 /l every 10 days while in group 5 HM and group 10 HM, the doses were 5 and 10 folds the 1 HM, respectively. Leaves and roots of control and heavy metal-stressed plants were harvested after 10 weeks for chlorophyll determination. The chlorophyll content, especially chlo. b, was significantly decreased with the increase in heavy metals stress in both plants. In leaves of heavy metal-stressed plants, the peroxidase level in different stress levels was increased with increasing stress levels in tomato and pea while catalase was unchanged in leaves of tomato in comparison with the control. The activities of catalase and peroxidase in roots of heavy metal-stressed plants were increased in group 5 HM then decreased in case of group 10 HM. The increase in enzyme activities demonstrated that tomato is more tolerant to heavy metals than pea

  5. Microfouling assessment and its control in a heavy water production unit

    International Nuclear Information System (INIS)

    Rajesh Kumar; Subba Rao, T.

    2015-01-01

    The water treatment plant (WTP) of a heavy water production unit was extensively fouled by microorganisms. On-site investigations showed severe algal and bacterial growth in the various units of WTP and very dense microbial fouling in the vacuum degasser (VD) unit. Digital and microscopic images showed that the microfouling problem was primarily due to a slime bacterium and a fungus. Microbiological analysis showed a bacterial count of ∼10 5 cfu ml -1 in the various sections of WTP. The slime/biofilm scrapings had very high bacterial population (>10 9 cfu cm -2 ). High organic carbon values in the system (5.0 to 19.5 ppm) had supported microbial growth in WTP and augmented resin fouling. Chlorination was inadequate in controlling microfouling, consequently chlorine dioxide was tested and found to be a better biocide. A 2.0% sodium omadine solution had completely inhibited the fouling fungus. (author)

  6. The Bare Critical Assembly of Natural Uranium and Heavy Water

    Energy Technology Data Exchange (ETDEWEB)

    Popovic, D [Boris Kidric Institute of Nuclear Sciences, Vinca, Belgrade (Yugoslavia)

    1958-07-01

    The first reactor built in Yugoslavia was the bare zero energy heavy water and natural uranium assembly at the Boris Kidric Institute of Nuclear Sciences, Belgrade. The reactor went critical on April 29, 1958. The possession of four tons of natural uranium metal and the temporary availability of seven tons of heavy water encouraged the staff of the Institute to build a critical assembly. A critical assembly was chosen, rather than high flux reactor, because the heavy water was available only temporarily. Besides, a 10 MW, enriched uranium, research reactor is being built at the same Institute and should be ready for operation late this year. It was supposed that the zero energy reactor would provide experience in carrying out critical experiments, operational experience with nuclear reactors, and the possibility for an extensive program in reactor physics. (author)

  7. Neutron disadvantage factors in heavy water and light water reactors

    International Nuclear Information System (INIS)

    Pop-Jordanov, J.

    1966-01-01

    A number od heavy water and light water reactor cells are analyzed in this paper by applying analytical methods of neutron thermalization. Calculations done according to the one-group Amouyal-Benoist method are included in addition. Computer codes for ZUSE Z-23 computer were written by applying both methods. The obtained results of disadvantage factors are then compared to results obtained by one-group P 3 approximation and by multigroup K7-THERMOS code [sr

  8. Water chemistry related problems in captive power plant of Heavy Water Plant [Manuguru

    International Nuclear Information System (INIS)

    Prasada Rao, G.; Mohapatra, C.

    2000-01-01

    This study is intended to improve the power generating capacity of Turbo Generator-3 in CPP. It was observed that steam flow through TG-3 was not as per rated; however there were no abnormal vibrations. After stopping and opening the turbine, deposits were found on turbine blade. Turbine blade scales were analysed for all the stages, HP, middle, LP, casings. Boiler drum water, feed water, DM water, filter water chemistry were studied. LP blade scale mainly consists of silica, whereas HP blade scale consists of iron oxide, sodium phosphate, silica etc. It was concluded that less generating capacity of power was because of scaling on turbine blade. (author)

  9. 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.

  10. Rhizobacteria and plant symbiosis in heavy metal uptake and its implications for soil bioremediation

    NARCIS (Netherlands)

    Sobariu, Dana Luminita; Fertu, Daniela Ionela Tudorache; Diaconu, Mariana; Pavel, Lucian Vasile; Hlihor, Raluca Maria; Drăgoi, Elena Niculina; Curteanu, Silvia; Lenz, Markus; Corvini, Philippe François Xavier; Gavrilescu, Maria

    2016-01-01

    Certain species of plants can benefit from synergistic effects with plant growth-promoting rhizobacteria (PGPR) that improve plant growth and metal accumulation, mitigating toxic effects on plants and increasing their tolerance to heavy metals. The application of PGPR as biofertilizers and

  11. Heavy metals concentrations in water bodies around aquamarine ...

    African Journals Online (AJOL)

    Water samples from three streams in the mining area of Eggon Hill were analysed. The Physicochemical values obtained were compared with WHO permissible standards in drinking water. Except for Cu and Zn with levels within permissible limits, other heavy metals determined were found to have levels above the WHO ...

  12. NORM emissions from heavy oil and natural gas fired power plants in Syria

    International Nuclear Information System (INIS)

    Al-Masri, M.S.; Haddad, Kh.

    2012-01-01

    Naturally occurring radioactive materials (NORM) have been determined in fly and bottom ash collected from four major Syrian power plants fired by heavy oil and natural gas. 210 Pb and 210 Po were the main NORM radionuclides detected in the fly and bottom ash. 210 Pb activity concentrations have reached 3393 ± 10 Bq kg −1 and 4023 ± 7 Bq kg −1 in fly ash and bottom ash, respectively; lower values of 210 Po were observed due to its high volatility. In addition, 210 Po and 210 Pb annual emissions in bottom ash from mixed (heavy oil and natural gas) fired power plants varied between 2.7 × 10 9 –7.95 × 10 9 Bq and 3.5 × 10 9 –10 10 Bq, respectively; higher emissions of 210 Po and 210 Pb from gas power plants being observed. However, the present study showed that 210 Po and 210 Pb emissions from thermal power plants fired by natural gas are much higher than the coal power plants operated in the World. - Highlights: ► NORM have been determined in fly and bottom ash collected from Syrian power plants fired by heavy oil and natural gas. ► 210 Pb and 210 Po were the main NORM radionuclides detected in the fly and bottom ash. ► 210 Po and 210 Pb annual emissions from these power plants were estimated.

  13. Method for separation of water from bituminous shales, etc. [water-free heavy product and water-containing light product

    Energy Technology Data Exchange (ETDEWEB)

    Hellsing, G H

    1908-10-13

    The method is characterized by conducting all the products of distillation, coming from the retorts, into a controllable system of condensation. This system of condensation is so constructed that the products of distillation are cooled to such a temperature that only the water-free heavy distillates are being condensed, and is furthermore so constructed that the other products of distillation, not yet condensed, are being condensed in an ordinary system of coolers. The purpose is to separate the distillates into a water-free heavy product and a water-containing lighter product. The patent includes an additional claim.

  14. Assessment of heavy metals in loose deposits in drinking water distribution system.

    Science.gov (United States)

    Liu, Quanli; Han, Weiqiang; Han, Bingjun; Shu, Min; Shi, Baoyou

    2018-06-09

    Heavy metal accumulation and potential releases from loose deposits in drinking water distribution system (DWDS) can have critical impacts on drinking water safety, but the associated risks have not been sufficiently evaluated. In this work, the potential biological toxicity of heavy metals in loose deposits was calculated based on consensus-based sediment quality guidelines, and the effects of some of the main water quality parameters, such as the pH and bicarbonate and phosphate content, on the release behaviors of pre-accumulated heavy metals were investigated. The results showed that heavy metals (Cu, As, Cr, Pb, and Cd) significantly accumulated in all the samples, but the contents of the heavy metals were multiple magnitudes lower than the Fe and Mn contents. The potential biotoxicity of As and Cu was relatively high, but the biotoxicity of Cd was negligible. The water quality can significantly influence the release of heavy metals from loose deposits. As the pH increased from 7.0 to 9.0, the release of As and Cr obviously increased. The release of As, Cu, Pb, and Cr also accelerated with the addition of phosphate (from 1 to 5 mg/L). In contrast to the trends for the pH and phosphate, variations in the bicarbonate content did not have a significant influence on the release of As and Cr. The release ratios of heavy metals in the samples were very low, and there was not a correlation between the release rate of the heavy metals in the loose deposits and their potential biotoxicity.

  15. Improvement Bio sorption of Heavy Metals from Industrial Wastewater Using Azolla

    International Nuclear Information System (INIS)

    Kotb, E.A.

    2012-01-01

    This study aims to improve the removal process which is vital for some heavy metals and natural radionuclides from industrial wastewater by bio sorption using living organisms with rapid growth as a trial to increase the efficient use of those organisms in the removal process is vital for the toxic elements. Bio sorption of heavy metal (Copper, Manganese, Iron, Zinc, Lead and Strontium) from industrial waste water (contaminated) with six different time periods for Azolla growth. The results indicate that Azolla plant able to on the absorption of ions of heavy elements and Sr and was up to the maximum absorption of most of the elements at a concentration of 50% of polluted water + 50% fresh water so we recommend using the plant Azolla as bio sorbent in the disposal and collection of heavy metals and radionuclides from industrial waste water and deal with it safely to humans and the environment. The results obtained confirm the ability of the fern to grow and absorb ion of heavy metal when mixed with industrial waste water and other sources of polluted water and act as bio filter. The optimum conditions for maximum removal of heavy metals were also determined. Study was conducted on recycling municipal wastewaters for cultivation of Azollamicrophylla biomass, which is used for inoculation into paddy fields as N bio fertilizer and has other applications as green manure,animal feed and bio filter.

  16. Experimental Analysis of Soil and Mandarin Orange Plants Treated with Heavy Metals Found in Oilfield-Produced Wastewater

    Directory of Open Access Journals (Sweden)

    Ailin Zhang

    2018-05-01

    Full Text Available Despite a declining trend, California remains a significant oil-producing state. For every barrel of crude oil, an average of 15 barrels of oilfield produced water (OPW is generated, some of which is used to boost freshwater sources for crop irrigation in the agriculturally important Central Valley. OPW is known to contain salts, metals, hydrocarbons, alkylphenols, naturally radioactive materials, biocides, and other compounds from drilling and production processes. Less is known about the potential uptake and accumulation of these compounds in crops and soil irrigated with OPW. In this study, 23 potted mandarin orange plants were irrigated two to three times weekly (depending on season with water containing three different concentrations of the known OPW heavy metals barium, chromium, lead, and silver. Seven sets of samples of soil and leaves and 11 fruits were collected and processed using microwave-assisted digestion (EPA Method 3051A. Processed samples were analyzed using inductively coupled plasma-optical emission spectroscopy (ICP-OES. Analysis of variance (ANOVA and covariance (ANCOVA coupled with Tukey’s honest significant difference test were used to examine the effects of metal concentrations in the irrigation water and number of watering days, respectively, on the metal concentrations in the soil, leaf, and fruit samples. Accumulation of barium in soil and leaves was strongly positively associated with sample and number of watering days, increasing nearly 2000-fold. Lead also showed an upward trend, increasing up to 560-fold over the baseline level. Total chromium showed an increase in the soil that tapered off, but less consistent results in the leaves and fruit. The silver results were more volatile, but also indicated at least some level of accumulation in the tested media. The smallest absolute accumulation was observed for chromium. Concentrations in the fruit were highest in the peel, followed by pith and juice. Accumulation

  17. Development of a portable heavy-water leak sensor based on laser absorption spectroscopy

    International Nuclear Information System (INIS)

    Lee, Lim; Park, Hyunmin; Kim, Taek-Soo; Kim, Minho; Jeong, Do-Young

    2016-01-01

    Highlights: • We developed a compact and portable laser sensor for a detection of heavy water leakage. • The sensor is wearable and also easy to use to search for the leak point. • It is sensitive enough to find invisible very tiny leaks. - Abstract: A compact and portable leak sensor based on cavity enhanced absorption spectroscopy has been newly developed for a detection of heavy water leakage which may happen in the facilities using heavy water such as pressurized heavy water reactor (PHWR). The developed portable sensor is suitable as an individual instrument for the measuring leak rate and finding the leak location because it is sufficiently compact in size and weight and operated by using an internal battery. In the performance test, the minimum detectable leak rate was estimated as 0.05 g/day from the calibration curve. This new sensor is expected to be a reliable and promising device for the detection of heavy water leakage since it has advantages on real-time monitoring and early detection for nuclear safety.

  18. Sediment, water pollution indicators for heavy metals

    International Nuclear Information System (INIS)

    Cabaleiro, S.; Horn, A.

    2010-01-01

    The complexity of an aquatic system requires consideration of its dynamics: spatial and temporal variations of physical, chemical and biological. Heavy metals have peculiar behavior in the aquatic system and may not be available in the waters, but on sediments.The sub-basin of the Sarandi stream is responsible for the contamination of Pampulha Lake. The Instituto Mineiro das Águas – IGAM - uses tool for monitoring the quality of surface water for developing strategies for conservation, restoration and rational use of water resources. So through the indices: IQA ( Indice de qualidade de águas) Index of water quality, and TC- toxic contamination, reduces conflicts, implements the disciplining of the environmental economy.This study determined the monitoring of sediment and water of Sarandi Stream, so in the samples collected during dry and rainy seasons (2007- 2008) were analyzed heavy metals (Cu, Cd, Cr, Co, Ni, Zn, Pb) and physical-chemical factors (conductivity, solids dissolved, temperature, turbidity). This allowed the determination of Hackanson factors of contamination and Muller Index geoaccumulation, indicating very high contamination in sediments regarding the elements Cr, Cu, and Cd, and high contamination for Pb, Zn, and Mn. The comparison with the indices of water quality- IQA (IGAM - 2006, 2007 and 2008), combined with exploratory data analysis and graphs of correlation between the variables indicated favorable conditions for metals contamination on water and sediment for these metals, besides allowing the identification of its source

  19. Microbial and Plant-Assisted Bioremediation of Heavy Metal Polluted Environments: A Review

    Directory of Open Access Journals (Sweden)

    Omena Bernard Ojuederie

    2017-12-01

    Full Text Available Environmental pollution from hazardous waste materials, organic pollutants and heavy metals, has adversely affected the natural ecosystem to the detriment of man. These pollutants arise from anthropogenic sources as well as natural disasters such as hurricanes and volcanic eruptions. Toxic metals could accumulate in agricultural soils and get into the food chain, thereby becoming a major threat to food security. Conventional and physical methods are expensive and not effective in areas with low metal toxicity. Bioremediation is therefore an eco-friendly and efficient method of reclaiming environments contaminated with heavy metals by making use of the inherent biological mechanisms of microorganisms and plants to eradicate hazardous contaminants. This review discusses the toxic effects of heavy metal pollution and the mechanisms used by microbes and plants for environmental remediation. It also emphasized the importance of modern biotechnological techniques and approaches in improving the ability of microbial enzymes to effectively degrade heavy metals at a faster rate, highlighting recent advances in microbial bioremediation and phytoremediation for the removal of heavy metals from the environment as well as future prospects and limitations. However, strict adherence to biosafety regulations must be followed in the use of biotechnological methods to ensure safety of the environment.

  20. Microbial and Plant-Assisted Bioremediation of Heavy Metal Polluted Environments: A Review

    Science.gov (United States)

    Ojuederie, Omena Bernard

    2017-01-01

    Environmental pollution from hazardous waste materials, organic pollutants and heavy metals, has adversely affected the natural ecosystem to the detriment of man. These pollutants arise from anthropogenic sources as well as natural disasters such as hurricanes and volcanic eruptions. Toxic metals could accumulate in agricultural soils and get into the food chain, thereby becoming a major threat to food security. Conventional and physical methods are expensive and not effective in areas with low metal toxicity. Bioremediation is therefore an eco-friendly and efficient method of reclaiming environments contaminated with heavy metals by making use of the inherent biological mechanisms of microorganisms and plants to eradicate hazardous contaminants. This review discusses the toxic effects of heavy metal pollution and the mechanisms used by microbes and plants for environmental remediation. It also emphasized the importance of modern biotechnological techniques and approaches in improving the ability of microbial enzymes to effectively degrade heavy metals at a faster rate, highlighting recent advances in microbial bioremediation and phytoremediation for the removal of heavy metals from the environment as well as future prospects and limitations. However, strict adherence to biosafety regulations must be followed in the use of biotechnological methods to ensure safety of the environment. PMID:29207531

  1. Mechanisms of stress avoidance and tolerance by plants used in phytoremediation of heavy metals

    OpenAIRE

    Jutsz Anna Małachowska; Gnida Anna

    2015-01-01

    Heavy metal pollution of soil is a significant environmental problem and has a negative impact on human health and agriculture. Phytoremediation can be an alternative environmental treatment technology, using the natural ability of plants to take up and accumulate pollutants or transform them. Proper development of plants in contaminated areas (e.g. heavy metals) requires them to generate the appropriate protective mechanisms against the toxic effects of these pollutants. This paper presents ...

  2. Do heavy metals and metalloids influence the detoxification of organic xenobiotics in plants?

    Science.gov (United States)

    Schröder, Peter; Lyubenova, Lyudmila; Huber, Christian

    2009-11-01

    Mixed pollution with trace elements and organic industrial compounds is characteristic for many spill areas and dumping sites. The danger for the environment and human health from such sites is large, and sustainable remediation strategies are urgently needed. Phytoremediation seems to be a cheap and environmentally sound option for the removal of unwanted compounds, and the hyperaccumulation of trace elements and toxic metals is seemingly independent from the metabolism of organic xenobiotics. However, stress reactions, ROS formation and depletion of antioxidants will also cause alterations in xenobiotic detoxification. Here, we investigate the capability of plants to detoxify chlorophenols via glutathione conjugation in a mixed pollution situation. Typha latifolia and Phragmites australis plants for the present study were grown under greenhouse conditions in experimental ponds. A Picea abies L. suspension culture was grown in a growth chamber. Cadmium sulphate, sodium arsenate and lead chloride in concentrations from 10 to 500 microM were administered to plants. Enzymes of interest for the present study were: glutathione transferase (GST), glutathione reductase, ascorbate peroxidase and peroxidase. Measurements were performed according to published methods. GST spectrophotometric assays included the model substrates CDNB, DCNB, NBC, NBoC and the herbicide Fluorodifen. Heavy metals lead to visible stress symptoms in higher plants. Besides one long-term experiment of 72 days duration, the present study shows time and concentration-dependent plant alterations already after 24 and 72 h Cd incubation. P. abies spruce cell cultures react to CdSO(4) and Na(2)HAsO(4) with an oxidative burst, similar to that observed after pathogen attack or elicitor treatment. Cd application resulted in a reduction in GSH and GSSG contents. When a heavy metal mixture containing Na(2)HAsO(4), CdSO(4) and PbCl(2) was applied to cultures, both GSH and GSSG levels declined. Incubation with

  3. Salvaging of service exposed cast alloy 625 cracker tubes of ammonia based Heavy Water Plants

    International Nuclear Information System (INIS)

    Kumar, Niraj; Misra, B.; Mahajan, M.P.; Mittra, J.; Sundararaman, M.; Chakravartty, J.K.

    2006-01-01

    In ammonia based heavy water plants, cracking of ammonia vapour, enriched in deuterium is carried out inside a cracker tube, packed with catalyst. These cracker tubes are made of alloy 625 (either wrought or cast) having dimensions of about 12.5 metres long, 88 mm outer diameter and 7.9 mm wall thickness. Seventy such tubes are housed in a typical ammonia cracker unit. The anticipated design life of such tube is 1,00,000 hrs. when operated at 720 degC based on creep as main degradation mechanism. Presently, these tubes are being operated at 680 degC skin temperature. Alloy 625 tubes are costly and normally not manufactured in India and are being imported. The cast alloy 625 cracker tubes have outlived their design life of 100,000 hrs. Therefore it has been decided to salvage the cast cracker tubes and extend the life further as it had already been done for wrought tubes. Similar to the earlier attempt of resolutionising of wrought alloy 625 tubes, efforts are in progress to salvage these cast tubes. In this study, cast tubes samples were subjected to solution-annealing treatment at two different temperatures, 1100degC and 1160degC respectively for two hrs. Mechanical properties along with the microstructure of the samples, which were resolutionized at 1160degC were comparable with that of virgin material. The 12.5 metres long cast alloy 625 cracker tubes will also be shortly solution-annealed in a specially designed resistance heating furnace after completing some more tests. (author)

  4. Enhancing phytoextraction: the effect of chemical soil manipulation on mobility, plant accumulation, and leaching of heavy metals.

    Science.gov (United States)

    Schmidt, Ulrich

    2003-01-01

    For heavy metal-contaminated agricultural land, low-cost, plant-based phytoextraction measures can be a key element for a new land management strategy. When agents are applied into the soil, the solubility of heavy metals and their subsequent accumulation by plants can be increased, and, therefore, phytoextraction enhanced. An overview is given of the state of the art of enhancing heavy metal solubility in soils, increasing the heavy metal accumulation of several high-biomass-yielding and metal-tolerant plants, and the effect of these measures on the risk of heavy metal leaching. Several organic as well as inorganic agents can effectively and specifically increase solubility and, therefore, accumulation of heavy metals by several plant species. Crops like willow (Salix viminalis L.), Indian mustard [Brassica juncea (L.) Czern.], corn (Zea mays L.), and sunflower (Helianthus annuus L.) show high tolerance to heavy metals and are, therefore, to a certain extent able to use the surpluses that originate from soil manipulation. More than 100-fold increases of lead concentrations in the biomass of crops were reported, when ethylenediaminetetraacetic acid (EDTA) was applied to contaminated soils. Uranium concentrations could be strongly increased when citric acid was applied. Cadmium and zinc concentrations could be enhanced by inorganic agents like elemental sulfur or ammonium sulfate. However, leaching of heavy metals due to increased mobility in soils cannot be excluded. Thus, implementation on the field scale must consider measures to minimize leaching. So, the application of more than 1 g EDTA kg(-1) becomes inefficient as lead concentration in crops is not enhanced and leaching rate increases. Moreover, for large-scale applications, agricultural measures as placement of agents, dosage splitting, the kind and amount of agents applied, and the soil properties are important factors governing plant growth, heavy metal concentrations, and leaching rates. Effective

  5. Heavy metal pollution in aquatic ecosystems and its phytoremediation using wetland plants: An ecosustainable approach

    Energy Technology Data Exchange (ETDEWEB)

    Rai, P.K. [Mizoram Central University, Tanhril (India). School for Earth Science & Natural Resource Management

    2008-07-01

    This review addresses the global problem of heavy metal pollution originating from increased industrialization and urbanization and its amelioration by using wetland plants both in a microcosm as well as natural/field condition. This review mentions salient features of wetland ecosystems, their vegetation component, and the pros and cons involved in heavy metal removal. Wetland plants are preferred over other bio-agents due to their low cost, frequent abundance in aquatic ecosystems, and easy handling. Constructed wetlands proved to be effective for the abatement of heavy metal pollution from acid mine drainage; landfill leachate; thermal power; and municipal, agricultural, refinery, and chlor-alkali effluent. the physicochemical properties of wetlands provide many positive attributes for remediating heavy metals. Typha, Phragmites, Eichhornia, Azolla, Lemna, and other aquatic macrophytes are some of the potent wetland plants for heavy metal removal. Biomass disposal problem and seasonal growth of aquatic macrophytes are some limitations in the transfer of phytoremediation technology from the laboratory to the field. However, the disposed biomass of macrophytes may be used for various fruitful applications. An ecosustainable model has been developed through the author's various works, which may ameliorate some of the limitations. The creation of more areas for phytoremediation may also aid in wetlands conservation. Genetic engineering and biodiversity prospecting of endangered wetland plants are important future prospects in this regard.

  6. Assessment of heavy metals concentration in drinking water ...

    African Journals Online (AJOL)

    The concentration of all the metals were considerably found to be below the limit permitted by WHO's drinking water guidelines (WHO 2005). Findings suggest that continues water quality monitoring should be carried out to check the concentration levels of heavy metals in that area, to prevent them from been above the limit ...

  7. Contents of some heavy metals in plants from Saginaw Bay (Lake Huron) and some small lakes in wilderness areas of Michigan's Upper Peninsula as analyzed by neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wells, J.R. (Cranbrook Institute of Science, Bloomfield Hill (USA)); Kaufman, P.B.; Jones, J.D.; Estabrook, G.F.; Ghosheh, N.S. (Michigan Univ., Ann Arbor (USA); Michigan Univ., Ann Arbor (USA). Michigan Memorial Phoenix Project; Eastern Michigan University, Ypsilanti (USA). Department of Biology)

    1982-01-01

    The highest concentrations of heavy metals occured in plants collected near the mouth of the Saginaw River. The alga, Cladophora sp., and the flowering plant, Typha augustifolia (cat-tail), are notable for the high concentration of heavy metals. In addition, several other species that were sampled from small lakes in Michigan's Upper Peninsula contained higher concentrations of certain metals (Ba, Cr, Rb) than from any samples obtained from Saginaw Bay. Different organs of the same species, or of the same plant, such as cut-tail, vary widely in concentrations of the same element. A computer-derived analysis of our data is presented, and the implications of our results as they relate to pollution by heavy metals in fresh-water lakes is discussed.

  8. Winter Maintenance Wash-Water Heavy Metal Removal Pilot Scale Evaluation

    Directory of Open Access Journals (Sweden)

    Christopher M. Miller

    2016-01-01

    Full Text Available To encourage sustainable engineering practices, departments of transportation are interested in reusing winter maintenance truck wash water as part of their brine production and future road application. Traffic-related metals in the wash water, however, could limit this option. The objective of this work was to conduct a pilot scale evaluation of heavy metal (copper, zinc, iron, and lead removal in a filtration unit (maximum flow rate of 45 L/minute containing proprietary (MAR Systems Sorbster® media. Three different trials were conducted and approximately 10,000 L of wash water collected from a winter maintenance facility in Ohio was treated with the pilot unit. Lab studies were also performed on six wash-water samples from multiple facilities to assess particle size removal and estimate settling time as a potential removal mechanism during wash-water storage. Pilot unit total metal removal efficiencies were 79%, 77%, 63%, and 94% for copper, zinc, iron, and lead, respectively. Particle settling calculation estimates for copper and zinc show that 10 hours in storage can also effectively reduce heavy metal concentrations in winter maintenance wash water in excess of 70%. These pilot scale results show promise for reducing heavy metal concentrations to an acceptable level for reuse.

  9. Effects of water stress, organic amendment and mycorrhizal inoculation on soil microbial community structure and activity during the establishment of two heavy metal-tolerant native plant species.

    Science.gov (United States)

    Fernández, D A; Roldán, A; Azcón, R; Caravaca, F; Bååth, E

    2012-05-01

    Our aim was to examine the effect of water stress on plant growth and development of two native plant species (Tetraclinis articulata and Crithmum maritimum) and on microbial community composition and activity in the rhizosphere soil, following the addition of an organic amendment, namely sugar beet residue (SBR), and/or the inoculation with an arbuscular mycorrhizal (AM) fungus, namely Glomus mosseae, in a non-sterile heavy metal-polluted soil. The AM inoculation did not have any significant effect on plant growth of both species. In T. articulata, SBR increased shoot growth, foliar P, total phospholipid fatty acids (PLFA), fungi-related PLFA, AM fungi-related neutral lipid fatty acid, bacterial gram-positive/gram-negative PLFA ratio and the β-glucosidase and dehydrogenase activities. SBR and AM inoculation increased phosphatase activity in T. articulata plants grown under drought conditions. In both plants, there was a synergistic effect between AM inoculation and SBR on mycorrhizal colonisation under drought conditions. In C. maritimum, the increase produced by the SBR on total amounts of PLFA, bacterial gram-positive-related PLFA and bacterial gram-negative-related PLFA was considerably higher under drought conditions. Our results suggest that the effectiveness of the amendment with regard to stimulating microbial communities and plant growth was largely limited by drought, particularly for plant species with a low degree of mycorrhizal colonisation.

  10. Thorium utilization in heavy water moderated Accelerator Driven Systems

    International Nuclear Information System (INIS)

    Bajpai, Anil; Degweker, S.B.; Ghosh, Biplab

    2011-01-01

    Research on Accelerator Driven Systems (ADSs) is being carried out around the world primarily with the objective of waste transmutation. Presently, the volume of waste in India is small and therefore there is little incentive to develop ADS based waste transmutation technology immediately. With limited indigenous U availability and the presence of large Th deposits in the country, there is a clear incentive to develop Th related technologies. India also has vast experience in design, construction and operation of heavy water moderated reactors. Heavy water moderated reactors employing solid Th fuels can be self sustaining, but the discharge burnups are too low to be economical. A possible way to improve the performance such reactors is to use an external neutron source as is done in ADS. This paper discusses our studies on Th utilization in heavy water moderated ADSs. The study is carried out at the lattice level. The time averaged k-infinity of the Th bundle from zero burnup up to the discharge burnup is taken to be the same as the core (ensemble) averaged k-infinity. For the purpose of the analysis we have chosen standard PHWR and AHWR assemblies. Variation of the pitch and coolant (H 2 O/D 2 O) are studied. Both, the once through cycle and the recycling option are studied. In the latter case the study is carried out for various enrichments (% 233 U in Th) of the recycled Th fuel bundles. The code DTF as modified for lattice and burnup calculations (BURNTRAN) was used for carrying out the study. The once through cycle represents the most attractive ADS concept (Th burner ADS) possible for Th utilization. It avoids reprocessing of Th spent fuel and in the ideal situation the use of any fissile material either initially or for sustaining itself. The gain in this system is however rather low requiring a high power accelerator and a substantial fraction of the power generated to be fed back to the accelerator. The self sustaining Th-U cycle in a heavy moderated ADS

  11. Treatment of Arsenazo III contaminated heavy water stored at Darlington

    International Nuclear Information System (INIS)

    Suryanarayan, S.; Husain, A.; Williams, D.

    2010-01-01

    Darlington Nuclear Generating Station (DNGS) has accumulated over 48 drums of chemistry laboratory waste arising from analysis of heavy water (D 2 O). Several organic, including Arsenazo III, and inorganic contaminants present in these drums results in high total organic carbon (TOC) and conductivity. These drums have not been processed due to uncertainties related to clean-up of Arsenazo III contaminated heavy water. This paper provides details of chemical characterization as well as bench scale studies performed to demonstrate the feasibility of treating the downgraded D 2 O to the stringent target specifications of <1 ppm TOC and <0.1mS/m conductivity, required for feed to the Station Upgrading Plant (SUP). Both ionic organic species such as glycolate, acetate and formate as well as neutral organics such as acetone, methanol and ethylene glycol were detected in all the samples. Morpholine and propylene glycol were detected in one sample. Arsenazo III was determined to be not a major contaminant (maximum 8.4 ppm) in these waste drums, compared to the other organic contaminants present. Various unit processes such as pH adjustment, granular activated carbon (GAC), ion exchange resin (IX), UV-peroxide oxidation (UV-H 2 O 2 ) treatments, nanofiltration (NF) as well as reverse osmosis (RO) were tested on a bench scale both singly as well as in various combinations to evaluate their ability to achieve the stringent target conductivity and TOC specifications. Among the various bench scale tests evaluated, the successive processing train used at DNGS and consisting of GAC+IX+UV/H 2 O 2 +IX (polishing) unit operations was found to meet target specifications for both conductivity and TOC. Unit processes comprising (GAC+IX) and (RO-double pass + GAC+IX) met conductivity targets but failed to meet TOC specifications. The results of GAC+IX tests clearly emphasize the importance of using low flow rates for successful reduction in both conductivity as well as TOC. Detailed

  12. Feasibility study and economic analysis on thorium utilization in heavy water reactors

    International Nuclear Information System (INIS)

    1978-07-01

    Even though natural uranium is a more easily usable fuel in heavy water reactors, thorium fuel cycles have also been considered owing to certain attractive features of the thorium fuel cycle in heavy water reactors. The relatively higher fission neutron yield per thermal neutron absorption in 233 U combined with the very low neutron absorption cross section of heavy water make it possible to achieve breeding in a heavy water reactor operating on Th- 233 U fuel cycle. Even if the breeding ratio is very low, once a self-sustaining cycle is achieved, thereafter dependence on uranium can be completely eliminated. Thus, with a self-sustaining Th- 233 U fuel cycle in heavy water reactors, a given quantity of natural uranium will be capable of supporting a much larger installed generating capacity to significantly longer period of time. However, since thorium does not contain any fissile isotope, fissile material has to be added at the beginning. Concentrated fissile material is considerably more expensive than the 235 U contained in natural uranium. This makes the fuel cycle cost higher with thorium fuel cycle, at least during the initial stages. The situation is made worse by the fact that, because of its higher thermal neutron absorption cross section, thorium requires a higher concentration of fissile material than 238 U. Nevertheless, because of the superior nuclear characteristics of 233 U, once uranium becomes more expensive, thorium fuel cycle in heavy water reactors may become economically acceptable. Furthermore, the energy that can be made available from a given quantity of uranium is considerably increased with a self-sustaining thorium fuel cycle

  13. 1170-MW(t) HTGR-PS/C plant application study report: heavy oil recovery application

    International Nuclear Information System (INIS)

    Rao, R.; McMain, A.T. Jr.

    1981-05-01

    This report describes the application of a high-temperature gas-cooled reactor (HTGR) which operates in a process steam/cogeneration (PS/C) mode in supplying steam for enhanced recovery of heavy oil and in exporting electricity. The technical and economic merits of an 1170-MW(t) HTGR-PS/C are compared with those of coal-fired plants and (product) oil-fired boilers for this application. The utility requirements for enhanced oil recovery were calculated by establishing a typical pattern of injection wells and production wells for an oil field similar to that of Kern County, California. The safety and licensing issues of the nuclear plant were reviewed, and a comparative assessment of the alternative energy sources was performed. Technically and economically, the HTGR-PS/C plant has attractive merits. The major offsetting factors would be a large-scale development of a heavy oil field by a potential user for the deployment of a 1170-MW(t) HTGR-PS/C; plant and the likelihood of available prime heavy oil fields for the mid-1990 operation

  14. Evaluation of heavy metal uptake and translocation by Acacia ...

    African Journals Online (AJOL)

    Many organic and inorganic pollutants, including heavy metals are being transported and mixed with the cultivated soils and water. Heavy metals are the most dangerous pollutants as they are nondegradable and accumulate and become toxic to plants and animals. An experiment was conducted in the glasshouse to ...

  15. Mechanisms of Heavy Metal Sequestration in Soils: Plant-Microbe Interactions and Organic Matter Aging

    Energy Technology Data Exchange (ETDEWEB)

    Teresa W.-M. Fan; Richard M. Higashi; David Crowley; Andrew N. Lane: Teresa A. Cassel; Peter G. Green

    2004-12-31

    For stabilization of heavy metals at contaminated sites, the three way interaction among soil organic matter (OM)-microbes-plants, and their effect on heavy metal binding is critically important for long-term sustainability, a factor that is poorly understood at the molecular level. Using a soil aging system, the humification of plant matter such as wheat straw was probed along with the effect on microbial community on soil from the former McClellan Air Force Base.

  16. Effects of Amended Sewage Sludge Application on Yield and Heavy Metal Uptake of Barley: A Case Study of Ahvaz Sewage Treatment Plant

    Directory of Open Access Journals (Sweden)

    Mostafa Chorom

    2007-06-01

    Full Text Available One aspect of sewage sludge application as an organic fertilizer on agricultural farms is environmental pollution concerns such as heavy metals uptake by plants. The aim of this study was to investigate the influence of amended sewage sludge application on yield and heavy metal uptake of Barley. This study was carried out over a period of barley growth with two treatments of sewage sludge (50 and 100 ton/ha and control treatment with four replicates arranged in a randomized complete block design. Plant samples were taken at three intervals (50, 90, and 180 days after sowing. The samples were prepared for measuring nutrients and heavy metals in stem, leaf, straw, and grain. Results of plant analysis showed that application of sewage sludge increased nitrogen, phosphorous, potassium and cadmium in vegetative parts compared to control. Grain analysis showed that application of sewage sludge significantly increased nitrogen, phosphorous, potassium, iron, and zinc. Grass yield significantly increased in the plot treated with 100 ton/ha sewage sludge. Grain yield in the two treatments significantly increased. The results revealed that the sewage sludge increased heavy metals uptake by plants but still below standard levels. It is, therefore, necessary to use the quantities of the elements introduced into soil and absorbed by plants in order to determine the toxicity level for each metal taking into account factors such as plant and soil types as well as environmental conditions. This information can then be used to determine sludge application quantities in each case. Meanwhile, sludge application may only be recommended for irrigated crops receiving adequate irrigation water due to its salinity. Moreover, it cannot be recommended for irrigated crops directly consumed by man.

  17. Method of extracting tritium from heavy water

    International Nuclear Information System (INIS)

    Tsuchiya, Hiroyuki; Kikuchi, Makoto; Asakura, Yamato; Yusa, Hideo.

    1979-01-01

    Purpose: To extract tritium in heavy water by combining isotope exchange reaction with liquefaction distillation to increase the concentration of recovered tritium, thereby reducing the quantity of radioactive wastes recovered. Constitution: Heavy water containing tritium from a reactor is introduced into a tritium separator through a conduit pipe. On the other hand, a D 2 gas is introduced through the conduit pipe in the lower part of a tritium separator to transfer tritium into D 2 gas by isotope exchange. The D 2 gas containing DT is introduced into a liquefaction distillation tower together with an outlet gas of a converter supplied through a pipeline. The converter is filled with net-like metals of platinum group such as Pt, Ni, Pd and the like, and the D 2 gas affluent in DT, extracted from the distillation tower is converted into D 2 and T 2 . The gas which has been introduced into the liquefaction distillation tower is liquefied. The D 2 gas of low boiling point components reaches the tower top, and the T 2 gas of high boiling point components is concentrated at the tower bottom, and is rendered into tritium water in a recoupler and stored in a water storage apparatus. (Yoshino, Y.)

  18. Safety Evaluation of Osun River Water Containing Heavy Metals and ...

    African Journals Online (AJOL)

    Summary: This study evaluated the pH, heavy metals and volatile organic compounds (VOCs) in Osun river water. It also evaluated its safety in rats. Heavy metals were determined by atomic absorption spectrophotometry (AAS) while VOCs were determined by gas chromatography coupled with flame ionization detector ...

  19. Rhizobacteria and plant symbiosis in heavy metal uptake and its implications for soil bioremediation.

    Science.gov (United States)

    Sobariu, Dana Luminița; Fertu, Daniela Ionela Tudorache; Diaconu, Mariana; Pavel, Lucian Vasile; Hlihor, Raluca-Maria; Drăgoi, Elena Niculina; Curteanu, Silvia; Lenz, Markus; Corvini, Philippe François-Xavier; Gavrilescu, Maria

    2017-10-25

    Certain species of plants can benefit from synergistic effects with plant growth-promoting rhizobacteria (PGPR) that improve plant growth and metal accumulation, mitigating toxic effects on plants and increasing their tolerance to heavy metals. The application of PGPR as biofertilizers and atmospheric nitrogen fixators contributes considerably to the intensification of the phytoremediation process. In this paper, we have built a system consisting of rhizospheric Azotobacter microbial populations and Lepidium sativum plants, growing in solutions containing heavy metals in various concentrations. We examined the ability of the organisms to grow in symbiosis so as to stimulate the plant growth and enhance its tolerance to Cr(VI) and Cd(II), to ultimately provide a reliable phytoremediation system. The study was developed at the laboratory level and, at this stage, does not assess the inherent interactions under real conditions occurring in contaminated fields with autochthonous microflora and under different pedoclimatic conditions and environmental stresses. Azotobacter sp. bacteria could indeed stimulate the average germination efficiency of Lepidium sativum by almost 7%, average root length by 22%, average stem length by 34% and dry biomass by 53%. The growth of L. sativum has been affected to a greater extent in Cd(II) solutions due its higher toxicity compared to that of Cr(VI). The reduced tolerance index (TI, %) indicated that plant growth in symbiosis with PGPR was however affected by heavy metal toxicity, while the tolerance of the plant to heavy metals was enhanced in the bacteria-plant system. A methodology based on artificial neural networks (ANNs) and differential evolution (DE), specifically a neuro-evolutionary approach, was applied to model germination rates, dry biomass and root/stem length and proving the robustness of the experimental data. The errors associated with all four variables are small and the correlation coefficients higher than 0

  20. X-ray fluorescence spectroscopic determination of heavy metals and ...

    African Journals Online (AJOL)

    Purpose: To determine the heavy metal and trace element composition of the powdered aerial parts of Origanum sipyleum L. and its water extract. Methods: The heavy metal and trace elements content of the powdered plant material and 2 % aqueous extract were evaluated by x-ray fluorescence spectroscopy with silicon ...

  1. Contamination of Soil, Water, Plant and Dust by Zinc, Lead and Cadmium in Southwest Isfahan

    Directory of Open Access Journals (Sweden)

    Nastaran Esmaeilpourfard

    2016-02-01

    Full Text Available Introduction Due to mining, considerable amounts of heavy metal bearing mineralsare scattered in the atmosphere in the form of dust and make the surrounding air, water and soils polluted.Runoff water movingfrom the mountainstowardsplains may also transport heavy metals from mines to the soils.One type ofpollutions is contamination withheavy metals.The purpose of the present research has been to investigate the effect of heavy metals of mine on soil, water, plant and dust pollution. Materials and Methods: Gushfil mine is located 3 kilometers southwest of Sepahanshahr, Isfahan. Soil profiles were dug 500 meters apart along three parallel transects, between east of Sepahanshahr and Gushfil mine. The profiles were described and samples were collected from their horizons. Ore, wells, plant and dust were sampled as well. Total concentrations of lead, zinc and cadmium were measured in the samples. To find the origin of polluted dust and soil, lead isotopes contents in the samples were measured and regressional relationships between the ratios of these contents were investigated. Results and Discussion Sepahanshahr soils are not contaminated by zinc, lead and cadmium, but within a distance of one to two kilometers from the Gushfil mine, the soils are polluted by zinc and lead. Cadmium contamination was not observed in the studied soils. In all of the soils, the heavy metals content varies downwards irregularly. The reason for this variation trend is that the studied soils are alluvial. In different periods of time, alluvium parent materials have been transported by runoff water from the lead and zinc mines towards the alluvial piedmont plain. The studied heavy metals have been distributed irregularly in different horizons of the soils that have been formed in these parent materials. Lead and cadmium concentrations of drinking water in the studied area are much higher than the maximum amount allowed by the World Health Organization. Cadmium content in

  2. Assessment of Heavy Metals in the Water of Sahastradhara Hill Stream at Dehradun, India

    Directory of Open Access Journals (Sweden)

    Pawan Kumar Bharti

    2014-09-01

    Full Text Available A study on heavy metals assessment in the water of Sahastradhara hill-stream was conducted with different five sites at significant differences. The present paper deals with the water quality status of Sahastradhara stream by the assessment of heavy metals. Heavy Metals were found in fluctuated trend from first upstream to last downstream. The values of almost all Heavy Metals were found in increasing manner especially after the fourth sampling site. After the third sampling station, a solid waste dumping site was found. So, there may be a relation between heavy metals in stream water and solid waste dumping site. Concentrations of all Heavy Metals at fourth and fifth sampling site were found very high. DOI: http://dx.doi.org/10.3126/ije.v3i3.11076 International Journal of Environment Vol.3(3 2014: 164-172

  3. Electrolytic separation factors for oxygen isotopes in light and heavy water solutions

    International Nuclear Information System (INIS)

    Gulens, J.; Olmstead, W.J.; Longhurst, T.H.; Gale, K.L.; Rolston, J.H.

    1987-01-01

    The electrolytic separation factor, α, has been measured for /sup 17/O and /sup 18/O at Pt and Ni anodes in both light and heavy water solutions of 6M KOH as a function of current density. For oxygen-17, isotopic separation effects were not observed, within the experimental uncertainty of +-2%, under all conditions studied. For oxygen-18, there is a small difference of 2% in α values between Pt and Ni in both light and heavy water solutions, but there is no significant difference in α values between light and heavy water solutions. In light waters solutions, the separation factor at Pt is small, α(/sup 18/O) ≤ 1.02 for i ≥ 0.1 A/cm/sub 2/. This value agrees reasonably well with theoretical estimates

  4. Pulse radiolysis studies of liquid heavy water at temperatures up to 250 degrees C

    International Nuclear Information System (INIS)

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

    2002-09-01

    This report documents the rate constants and associated activation energies for the reactions of the primary radical species, e aq - , ·OD and ·D, which are formed during the radiolysis of heavy water within the temperature range 20 to 250 o C. These heavy-water data have been compared with the corresponding information for light water. These kinetic data form part of the database that is required to model the aqueous radiation chemistry that occurs within the core of the heavy water cooled and moderated CANDU reactor. (author)

  5. Pulse radiolysis studies of liquid heavy water at temperatures up to 250 degrees C

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-09-01

    This report documents the rate constants and associated activation energies for the reactions of the primary radical species, e{sub aq}{sup -}, {center_dot}OD and {center_dot}D, which are formed during the radiolysis of heavy water within the temperature range 20 to 250 {sup o}C. These heavy-water data have been compared with the corresponding information for light water. These kinetic data form part of the database that is required to model the aqueous radiation chemistry that occurs within the core of the heavy water cooled and moderated CANDU reactor. (author)

  6. The Battle for Heavy Water Three physicists' heroic exploits

    CERN Multimedia

    2002-01-01

    Up until the end of the 1970s you could still catch a glimpse of his massive silhouette in the corridors of CERN. Lew Kowarksi, one of the pioneers of the Laboratory, was not only a great physicist; he was also a genuine hero of World War II. In 1940, along with Frédéric Joliot and Hans von Halban, Lew Kowarski managed to get the entire world supply of heavy water away to safety from the Nazis after a fantastic escape from occupied France. At the end of the war, the three physicists played themselves in a film about their adventures entitled 'la Bataille de l'eau lourde'. This film, which has been loaned to us by the French National Film Library, will be shown at CERN for the first time next Thursday. At the beginning of the war, heavy water (D20, two atoms of deuterium and one oxygen atom) was of strategic importance. In 1939 Frédéric Joliot, aided by Hans von Halban and Lew Kowarski, demonstrated the nuclear chain reaction and the moderator role that heavy water plays in it. A few weeks before the inv...

  7. Role of 24-epibrassinolide (EBL) in mediating heavy metal and pesticide induced oxidative stress in plants: A review.

    Science.gov (United States)

    Shahzad, Babar; Tanveer, Mohsin; Che, Zhao; Rehman, Abdul; Cheema, Sardar Alam; Sharma, Anket; Song, He; Rehman, Shams Ur; Zhaorong, Dong

    2018-01-01

    Industrialization and urbanization have posed serious threats to the environment. Excessive release of heavy metals from industrial effluents and overuse of pesticides in modern agriculture are limiting crop production by polluting environment and deteriorating food quality. Sustaining food quality under heavy metals and pesticide stress is crucial to meet the increasing demands for food. 24-Epibrassinolide (EBL), a ubiquitously occurring plant growth hormone shows great potential to alleviate heavy metals and pesticide stress in plants. This review sums up the potential role of EBL in ameliorating heavy metals and pesticide toxicity in plants extensively. EBL application increases plant's overall growth, biomass accumulation and photosynthetic efficiency by the modulation of numerous biochemical and physiological processes under heavy metals and pesticide stress. In addition, EBL scavenges reactive oxygen species (ROS) by triggering the production of antioxidant enzymes such as SOD, CAT, POX etc. EBL also induces the production of proline and soluble proteins that helps in maintaining osmotic potential and osmo-protection under both heavy metals and pesticide stress. At the end, future needs of research about the application of 24-epibrassinolide have also been discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Heavy Metal Pollution and Ecological Assessment around the Jinsha Coal-Fired Power Plant (China).

    Science.gov (United States)

    Huang, Xianfei; Hu, Jiwei; Qin, Fanxin; Quan, Wenxuan; Cao, Rensheng; Fan, Mingyi; Wu, Xianliang

    2017-12-18

    Heavy metal pollution is a serious problem worldwide. In this study, 41 soil samples and 32 cabbage samples were collected from the area surrounding the Jinsha coal-fired power plant (JCFP Plant) in Guizhou Province, southwest China. Pb, Cd, Hg, As, Cu and Cr concentrations in soil samples and cabbage samples were analysed to study the pollution sources and risks of heavy metals around the power plant. The results indicate that the JCFP Plant contributes to the Pb, Cd, As, Hg, Cu, and Cr pollution in nearby soils, particularly Hg pollution. Cu and Cr in soils from both croplands and forestlands in the study area derive mainly from crustal materials or natural processes. Pb, Cd and As in soils from croplands arise partly through anthropogenic activities, but these elements in soils from forestlands originate mainly from crustal materials or natural processes. Hg pollution in soils from both croplands and forestlands is caused mainly by fly ash from the JCFP Plant. The cabbages grown in the study area were severely contaminated with heavy metals, and more than 90% of the cabbages had Pb concentrations exceeding the permissible level established by the Ministry of Health and the Standardization Administration of the People's Republic of China. Additionally, 30% of the cabbages had As concentrations exceeding the permissible level. Because forests can protect soils from heavy metal pollution caused by atmospheric deposition, close attention should be given to the Hg pollution in soils and to the concentrations of Pb, As, Hg and Cr in vegetables from the study area.

  9. Influence of water relations and growth rate on plant element uptake and distribution

    International Nuclear Information System (INIS)

    Greger, Maria

    2006-02-01

    Plant uptake of Ni, Sr, Mo, Cs, La, Th, Se, Cl and I was examined to determine how plant water relations and growth rate influence the uptake and distribution of these elements in the studied plants. The specific questions were how water uptake and growth rate influenced the uptake of various nuclides and how transpiration influenced translocation to the shoot. The knowledge gained will be used in future modelling of radionuclide leakage from nuclear waste deposits entering the ecosystem via plants. The plant studied was willow, Salix viminalis, a common plant in the areas suggested for waste disposal; since there can be clone variation, two different clones having different uptake properties for several other heavy metals were used. The plants were grown in nutrient solution and the experiments on 3-month-old plants were run for 3 days. Polyethylene glycol was added to the medium to decrease the water uptake rate, a fan was used to increase the transpiration rate, and different light intensities were used to produce different growth rates. Element concentration was analysed in roots and shoots. The results show that both the uptake and distribution of various elements are influenced in different ways and to various extents by water flow and plant growth rate, and that it is not possible from the chemical properties of these elements to know how they will react. However, in most cases increased growth rate diluted the concentration of the element in the tissue, reduced water uptake reduced the element uptake, while transpiration had no effect on the translocation of elements to the shoot. The clones did not differ in terms of either the uptake or translocation of the elements, except that I was not taken up and translocated to the shoot in one of the clones when the plant water flow or growth rate was too low. Not all of the elements were found in the plant in the same proportions as they had been added to the nutrient solution

  10. Influence of water relations and growth rate on plant element uptake and distribution

    Energy Technology Data Exchange (ETDEWEB)

    Greger, Maria [Stockholm Univ. (Sweden). Dept. of Botany

    2006-02-15

    Plant uptake of Ni, Sr, Mo, Cs, La, Th, Se, Cl and I was examined to determine how plant water relations and growth rate influence the uptake and distribution of these elements in the studied plants. The specific questions were how water uptake and growth rate influenced the uptake of various nuclides and how transpiration influenced translocation to the shoot. The knowledge gained will be used in future modelling of radionuclide leakage from nuclear waste deposits entering the ecosystem via plants. The plant studied was willow, Salix viminalis, a common plant in the areas suggested for waste disposal; since there can be clone variation, two different clones having different uptake properties for several other heavy metals were used. The plants were grown in nutrient solution and the experiments on 3-month-old plants were run for 3 days. Polyethylene glycol was added to the medium to decrease the water uptake rate, a fan was used to increase the transpiration rate, and different light intensities were used to produce different growth rates. Element concentration was analysed in roots and shoots. The results show that both the uptake and distribution of various elements are influenced in different ways and to various extents by water flow and plant growth rate, and that it is not possible from the chemical properties of these elements to know how they will react. However, in most cases increased growth rate diluted the concentration of the element in the tissue, reduced water uptake reduced the element uptake, while transpiration had no effect on the translocation of elements to the shoot. The clones did not differ in terms of either the uptake or translocation of the elements, except that I was not taken up and translocated to the shoot in one of the clones when the plant water flow or growth rate was too low. Not all of the elements were found in the plant in the same proportions as they had been added to the nutrient solution.

  11. Direct harvesting of Helium-3 (3He) from heavy water nuclear reactors

    International Nuclear Information System (INIS)

    Bentoumi, G.; Didsbury, R.; Jonkmans, G.; Rodrigo, L.; Sur, B.

    2013-01-01

    The thermal neutron activation of deuterium inside a heavy-water-moderated or -cooled nuclear reactor produces a build-up of tritium in the heavy water. The in situ decay of tritium can, for certain reactor types and operating conditions, produce potentially useable amounts of 3 He, which can be directly extracted via the heavy-water cover gas without first separating, collecting and storing tritium outside the reactor. It is estimated that the amount of 3 He available for recovery from the moderator cover gas of a 700 MWe class Pressurized Heavy Water Reactor (PHWR) ranges from 0.1 to 0.7 m 3 (STP) per annum, varying with the tritium activity buildup in the moderator. The harvesting of 3 He would generate approximately 12.7 m 3 (STP) of 3 He, worth more than $30M at current market rates, over a typical 25-year operating cycle of the PHWR. This paper discusses the production of 3 He in the moderator of a PHWR and its extraction from the 4 He moderator cover gas system using conventional methods. (author)

  12. Heavy metals and inorganic constituents in medicinal plants of ...

    African Journals Online (AJOL)

    Heavy metals such as Cr, Fe, Zn, Mn, Ni, Pb, Cu and Cd, and inorganic ions like HCO3-, CO32-, Ca2+, Mg2+, Cl-, Na+, SO42-, NO3-, Fe2+ and F- were investigated in medicinally important plants: Taraxacam officinale, Cichorium intybus and Figonia critica, applying atomic absorption spectrophotometer techniques. In the ...

  13. Microorganisms in heavy metal bioremediation: strategies for applying microbial-community engineering to remediate soils

    Directory of Open Access Journals (Sweden)

    Jennifer L. Wood

    2016-06-01

    Full Text Available The remediation of heavy-metal-contaminated soils is essential as heavy metals persist and do not degrade in the environment. Remediating heavy-metal-contaminated soils requires metals to be mobilized for extraction whilst, at the same time, employing strategies to avoid mobilized metals leaching into ground-water or aquatic systems. Phytoextraction is a bioremediation strategy that extracts heavy metals from soils by sequestration in plant tissues and is currently the predominant bioremediation strategy investigated for remediating heavy-metal-contaminated soils. Although the efficiency of phytoextraction remains a limiting feature of the technology, there are numerous reports that soil microorganisms can improve rates of heavy metal extraction.This review highlights the unique challenges faced when remediating heavy-metal-contaminated soils as compared to static aquatic systems and suggests new strategies for using microorganisms to improve phytoextraction. We compare how microorganisms are used in soil bioremediation (i.e. phytoextraction and water bioremediation processes, discussing how the engineering of microbial communities, used in water remediation, could be applied to phytoextraction. We briefly outline possible approaches for the engineering of soil communities to improve phytoextraction either by mobilizing metals in the rhizosphere of the plant or by promoting plant growth to increase the root-surface area available for uptake of heavy metals. We highlight the technological advances that make this research direction possible and how these technologies could be employed in future research.

  14. Special operations in the heavy water system, III-2; III-2 Posebne operacije u sistemu teske vode

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1989-07-01

    Special operations in the heavy water system described in this chapter are as follows: treatment, drainage and pouring of heavy water, emptying of the heavy water system, cleaning and vacuuming of the heavy water system. [Serbo-Croat] Posebne operacije u sistemu teske vode opisane u ovom poglavlju su: tretiranje, dreniranje i razlivanje teske vode, praznjenje sistema teske vode, 'ispiranje' i vakumiranje sistema teske vode.

  15. The effect of technogenic emissions on the heavy metals accumulation by herbaceous plants.

    Science.gov (United States)

    Chaplygin, Victor; Minkina, Tatiana; Mandzhieva, Saglara; Burachevskaya, Marina; Sushkova, Svetlana; Poluektov, Evgeniy; Antonenko, Elena; Kumacheva, Valentina

    2018-02-07

    The effect of technogenic emissions on the input of Pb, Zn, Cd, Cu, Mn, Cr, and Ni into plants from the Poaceae and Asteraceae families has been studied. Soil and plant contamination by anthropogenic emissions from industrial enterprises leads the decreasing of crop quality; therefore, the monitoring investigation of plants and soils acquires special importance. The herbaceous plants may be used as bioindicators for main environmental changes. It was found that the high level of anthropogenic load related to atmospheric emissions from the power plant favors the heavy metal (HM) accumulation in herbaceous plants. Contamination with Pb, Cd, Cr, and Ni was revealed in plants growing near the power plant. Heavy metals arrive to plants from the soil in the form of mobile compounds. Plant family is one of the main factors affecting the HM distribution in the above- and underground parts of plants. Plants from the Poaceae family accumulate less chemical elements in their aboveground parts than the Asteraceae plants. Ambrosia artemisiifolia and Artemisia austriaca are HM accumulators. For assessing the stability of plants under contamination with HMs, metal accumulation by plants from soil (the bioconcentration factor) and metal phytoavailability from plants above- and underground parts (the acropetal coefficient) were calculated. According to the bioconcentration factor and translocation factor values, Poaceae species are most resistant to technogenic contamination with HMs. The translocation factor highest values were found for Tanacetum vulgare; the lowest bioconcentration factor values were typical for Poa pratensis.

  16. Surface Water Modeling Using an EPA Computer Code for Tritiated Waste Water Discharge from the heavy Water Facility

    International Nuclear Information System (INIS)

    Chen, K.F.

    1998-06-01

    Tritium releases from the D-Area Heavy Water Facilities to the Savannah River have been analyzed. The U.S. EPA WASP5 computer code was used to simulate surface water transport for tritium releases from the D-Area Drum Wash, Rework, and DW facilities. The WASP5 model was qualified with the 1993 tritium measurements at U.S. Highway 301. At the maximum tritiated waste water concentrations, the calculated tritium concentration in the Savannah River at U.S. Highway 301 due to concurrent releases from D-Area Heavy Water Facilities varies from 5.9 to 18.0 pCi/ml as a function of the operation conditions of these facilities. The calculated concentration becomes the lowest when the batch releases method for the Drum Wash Waste Tanks is adopted

  17. Plant growth and development vs. high and low levels of plant-beneficial heavy metal ions

    Directory of Open Access Journals (Sweden)

    Namira Arif

    2016-11-01

    Full Text Available Heavy metals (HMs exists in the environment in both forms as essential and non-essential. These HM ions enter in soil biota from various sources like natural and anthropogenic. Essential HMs such as cobalt (Co, copper (Cu, iron (Fe, manganese (Mn, molybdenum (Mo, nickel (Ni, and zinc (Zn plays a beneficial role in plant growth and development. At optimum level these beneficial elements improves the plant’s nutritional level and also several mechanisms essential for the normal growth and better yield of plants. The range of their optimality for land plants is varied. Plant uptake heavy metals as a soluble component or solubilized them by root exudates. While their presence in excess become toxic for plants that switches the plant’s ability to uptake and accumulate other nonessential elements. The increased amount of HMs within the plant tissue displays direct and indirect toxic impacts. Such direct effects are the generation of oxidative stress which further aggravates inhibition of cytoplasmic enzymes and damage to cell structures. Although, indirect possession is the substitution of essential nutrients at plant’s cation exchange sites. These ions readily influence role of various enzymes and proteins, arrest metabolism, and reveal phytotoxicity. On account of recent advancements on beneficial HMs ions Co, Cu, Fe, Mn, Mo, Ni, and Zn in soil-plant system, the present paper: overview the sources of HMs in soils and their uptake and transportation mechanism, here we have discussed the role of metal transporters in transporting the essential metal ions from soil to plants. The role played by Co, Cu, Fe, Mn, Mo, Ni, and Zn at both low and high level on the plant growth and development and the mechanism to alleviate metal toxicity at high level have been also discussed. At the end, on concluding the article we have also discussed the future perspective in respect to beneficial HM ions interaction with plant at both levels.

  18. Adsorption of heavy metal in freeway by asphalt block

    Science.gov (United States)

    Zheng, Chaocheng

    2017-08-01

    Heavy metals are toxic, persistent, and carcinogenic in freeway. Various techniques are available for the removal of heavy metals from waste water among soils during freeway including ion-exchange, membrane filtration, electrolysis, coagulation, flotation, and adsorption. Among them, bio-sorption processes are widely used for heavy metal and other pollutant removal due to its sustainable, rapid and economic. In this paper, heavy metal removal facilitated by adsorption in plants during freeway was illustrated to provide concise information on exploring the adsorption efficiency.

  19. Detritiation plant of the Laue Longevin Institute

    International Nuclear Information System (INIS)

    Pautrot, P.; Arnaud, J.P.

    The detritiation plant at the Laue Longevin Institute, which is to serve the double function of detritiation and reconcentration of heavy water in the high flux reactor (HFR) is described. The process effected in this unit combines a catalytic exchange between heavy water and deuterium and a distillation of liquid deuterium. Placed in operation at the end of 1971, this installation processed heavy water from the HFR from the beginning of 1972, maintaining an isotopic concentration above 99.6 percent and a tritium activity below 2 Ci/liter. Exceptionally satisfactory performance now permits also processing of tritiated heavy water from external sources

  20. DEVELOPMENT OF A PLANT TEST SYSTEM FOR EVALUATION OF THE TOXICITY OF METAL CONTAMINATED SOILS. I. SENSITIVITY OF PLANT SPECIES TO HEAVY METAL STRESS

    Directory of Open Access Journals (Sweden)

    Andon VASSILEV

    2001-09-01

    Full Text Available The sensitivity of young bean, cucumber and lettuce plants to heavy metals stress was studied at control conditions in a climatic room. The plants were grown in pots with perlite and supplied daily by half-strength Hoagland nutrient solution. The plants were treated for 8 days with different heavy metal doses (full, ½ and ¼ starting at appearance of the fi rst true leaf (cucumber and bean or the full development of the second leaf (lettuce. The full dose consisted 500 μM Zn, 50 μM Cd and 20 μM Cu added to the nutrient solution. Based on the measured morphological (fresh weight, leaf area, root length and physiological parameters (photosynthetic pigments content and activity of guaiacol peroxidase in roots, the cucumber plants presented the highest sensitivity to heavy metal stress.

  1. Urban water pollution by heavy metals and health implication in ...

    African Journals Online (AJOL)

    Studies of common heavy metals were conducted at Onitsha, Anambra State, the most urbanized city in Southeastern Nigeria. It was discovered that both surface and subsurface water were heavily polluted. Seven (7) heavy metals namely: arsenic (As+2), cadmium (Cd+2), lead (Pb+2), mercury (Hg+2), zinc (Zn+2), copper ...

  2. Development of waste water reuse water system for power plants

    Energy Technology Data Exchange (ETDEWEB)

    Park, K K; Kim, D H; Weon, D Y; Yoon, S W; Song, H R [Korea Electric Power Research Institute, Taejeon (Korea, Republic of)

    1998-12-31

    1. Status of waste water discharge at power plants 2. Present status of waste water reuse at power plants 3. Scheme of waste water reuse at power plants 4. Standardization of optimum system for waste water reuse at power plants 5. Establishment of low cost zero discharge system for waste water 6. Waste water treatment technology of chemical cleaning. (author). 132 figs., 72 tabs.

  3. Development of waste water reuse water system for power plants

    Energy Technology Data Exchange (ETDEWEB)

    Park, K.K.; Kim, D.H.; Weon, D.Y.; Yoon, S.W.; Song, H.R. [Korea Electric Power Research Institute, Taejeon (Korea, Republic of)

    1997-12-31

    1. Status of waste water discharge at power plants 2. Present status of waste water reuse at power plants 3. Scheme of waste water reuse at power plants 4. Standardization of optimum system for waste water reuse at power plants 5. Establishment of low cost zero discharge system for waste water 6. Waste water treatment technology of chemical cleaning. (author). 132 figs., 72 tabs.

  4. Novel polymer-based nanocomposites for application in heavy metal pollution remediation

    CSIR Research Space (South Africa)

    Kotzé-Jacobs, L

    2012-10-10

    Full Text Available and kidney damage and also cancer ? Heavy metals can accumulate in food sources through heavy metal contamination of soil and plants ? CSIR 2012 Slide 3 Removal of heavy metals ? Small volume applications: ion exchange ? Larger volumes eg. acid mine... pollution, treatment shortfalls at municipalities and contaminated surface water discharges ? Accumulation of heavy metals and endocrine disrupters ? CSIR 2012 Slide 2 Introduction: Heavy metals ? Cr, Ni, Cu, Pb, As etc. ? Exposure can cause liver...

  5. Carbon steel protection in G.S. (Girlder sulfide) heavy water fabrication plants. Control of iron content at the final stage of passivation. Pt. 10

    International Nuclear Information System (INIS)

    Rojo, E.A.

    1991-01-01

    This paper is part of a series which corresponds to the carbon steel behaviour as construction material for Girlder sulfide (G.S.) heavy water plants. The present work analyses the iron concentration study during passivation in the passivating fluid. At the beginning, during the formation of the most soluble sulfide -that is the mackinawite-, the iron concentration reaches more than 10 ppm. After some days, this iron concentration begins to decrease up to its stabilization under 0.1 ppm. This process, which occurs in the 9th. and 11th days, indicates that passivation is over, and that a pyrite and pyrrhotite-pyrite layer exists on the iron. Some differences exist between the results obtained and those previsible for the iron sulfides solubilities. In spite of these difficulties, the procedure is perfectly adequate to judge the passivation final stage. (Author) [es

  6. Heavy-water extraction from non-electrolytic hydrogen streams

    International Nuclear Information System (INIS)

    LeRoy, R.L.; Hammerli, M.; Butler, J.P.

    1981-01-01

    Heavy water may be produced from non-electrolytic hydrogen streams using a combined electrolysis and catalytic exchange process. The method comprises contacting feed water in a catalyst column with hydrogen gas originating partly from a non-electrolytic hydrogen stream and partly from an electrolytic hydrogen stream, so as to enrich the feed water with the deuterium extracted from both the non-electrolytic and electrolytic hydrogen gas, and passing the deuterium water to an electrolyser wherein the electrolytic hydrogen gas is generated and then fed through the catalyst column. (L.L.)

  7. Health risk assessment of heavy metals in soil-plant system amended with biogas slurry in Taihu basin, China.

    Science.gov (United States)

    Bian, Bo; Lin, Cheng; Lv, Lin

    2016-09-01

    Biogas slurry is a product of anaerobic digestion of manure that has been widely used as a soil fertilizer. Although the use for soil fertilizer is a cost-effective solution, it has been found that repeated use of biogas slurry that contains high heavy metal contents can cause pollution to the soil-plant system and risk to human health. The objective of this study was to investigate effects of biogas slurry on the soil-plant system and the human health. We analyzed the heavy metal concentrations (including As, Pb, Cu, Zn, Cr and Cd) in 106 soil samples and 58 plant samples in a farmland amended with biogas slurry in Taihu basin, China. Based on the test results, we assessed the potential human health risk when biogas slurry containing heavy metals was used as a soil fertilizer. The test results indicated that the Cd and Pb concentrations in soils exceeded the contamination limits and Cd exhibited the highest soil-to-root migration potential. Among the 11 plants analyzed, Kalimeris indica had the highest heavy metal absorption capacity. The leafy vegetables showed higher uptake of heavy metals than non-leafy vegetables. The non-carcinogenic risks mainly resulted from As, Pb, Cd, Cu and Zn through plant ingestion exposure. The integrated carcinogenic risks were associated with Cr, As and Cd in which Cr showed the highest risk while Cd showed the lowest risk. Among all the heavy metals analyzed, As and Cd appeared to have a lifetime health threat, which thus should be attenuated during production of biogas slurry to mitigate the heavy metal contamination.

  8. On the domestically-made heavy forging for reactor pressure vessels of PWR nuclear power plant

    International Nuclear Information System (INIS)

    Pan Xiren; Zhang Chen.

    1988-01-01

    The present situation of the foreign heavy forgings for nuclear reactor pressure vessels and the heavy forgings condition which is used for the Qinshan 300MWe nuclear power plant are described. Some opinions of domestic products is proposed

  9. Practical consequences of the Water Framework Directive implementation for combustion plants. New water cleaning technologies and methods for improvement of effluent discharges; Praktiska konsekvenser foer foerbraenningsanlaeggningar vid infoerandet av Vattendirektivet. Nya reningstekniker och foerbaettringsaatgaerder vid utslaepp till vatten

    Energy Technology Data Exchange (ETDEWEB)

    Axby, Fredrik; Hansson, Christina [Carl Bro Energikonsult AB, Malmoe (Sweden)

    2004-11-01

    As a consequence of the growing impact on water resources the Water Framework Directive was legislated in 2000. The directive should ensure that a 'good water status' and entail a coordinated legislation striving for a long-term protection of all water resources. Stakeholders should be able to participate in the preparations of river basin management plans and programs of measures. District based water authorities will administrate the implementation and are mandated to decide upon regional environmental quality standards and promulgate fees for water use and discharges. The Directive contains a list of 33 prioritized substances that should be reduced or phased out. Discharges from combustion plants contain twelve, polyaromatic hydrocarbons (PAH) and heavy metals. PAH and heavy metals impacts growth and vital functions as respiration and photosynthesis of water living organisms and induces cancer in humans. NOEC-values (NO Effect Concentration) state manageable substance concentrations for an organism. Flue gas condensate contains concentrations of some of the substances which impact exceeds the critical state level. Extended sewage treatment could thus be needed. Sludge, wash and soot water contains elevated levels of heavy metals. This water is normally treated by municipal sewage treatment. Further treatment at plant site could be relevant. Presence of PAH and heavy metals in leach water depends on the precipitation. Additional flowing-independent water treatment could be relevant. It is very uncertain how plant owners will be affected. Licenses could be reviewed and standards could be raised for sensitive recipients; new limits for prioritized substances and standards for other types of discharges and water fees could be added. Respites could be given if costs exceed the benefits. Location, ecotoxicological risk assessments and precautionary measures could become more relevant in an EIA. Pricing of water could take place by using a system of emissions

  10. Heavy metal contamination and ecological risk of farmland soils adjoining steel plants in Tangshan, Hebei, China.

    Science.gov (United States)

    Yang, Liyun; Yang, Maomao; Wang, Liping; Peng, Fei; Li, Yuan; Bai, Hao

    2018-01-01

    The purpose of this study was to determine the heavy metal concentrations and ecological risks to farmland soils caused by atmospheric deposition adjoining five industrial steel districts in Tangshan, Hebei, China. A total of 39 topsoil samples from adjoining these plants were collected and analyzed for Pb, Zn, Cu, Cr, and As. The geo-accumulation index (Igeo) and potential ecological risk index (PERI) were calculated to assess the heavy metal pollution level in soils. The results showed that the levels of Pb and As in farmland soils adjoining all steel plants were more than the background value, with the As content being excessively high. The Cr and Cu contents of some samples were over the background values, but the Zn content was not. In all the research areas, the largest Igeo value of the heavy metals was for As, followed by Pb, and the largest monomial PERI ([Formula: see text]) was As, which showed that the pollution of As in farmland soils was significant and had considerable ecological risk. Additionally, the heavy metal sequential extraction experiments showed that Pb and Cr, which exceeded the background value, were present in about 20% of the exchangeable and carbonate-bound fractions in the soils surrounding some steel plants. This would imply the risk of these heavy metals being absorbed and accumulated by the crops. Therefore, the local government needs to control the pollution of heavy metals in the farmland soils adjoining the steel plant as soon as possible, in order to avoid possible ecological and food safety risks.

  11. Solubilities of boric acid in heavy water

    International Nuclear Information System (INIS)

    Nakai, Shigetsugu; Aoi, Hideki; Hayashi, Ken-ichi; Katoh, Taizo; Watanabe, Takashi.

    1988-01-01

    A gravimetric analysis using meta-boric acid (HBO 2 or DBO 2 ) as a weighing form has been developed for solubility measurement. The method gave satisfactory results in preliminary measurement of solubilities of boric acid in light water. By using this method, the solubilities of 10 B enriched D 3 BO 3 in heavy water were measured. The results are as follows; 2.67 (7deg C), 3.52 (15deg C), 5.70 (30deg C), 8.87 (50deg C) and 12.92 (70deg C) w/o, respectively. These values are about 10% lower than those in light water. Thermodynamical consideration based on the data shows that boric acid is the water structure breaker. (author)

  12. Pollution Status of Pakistan: A Retrospective Review on Heavy Metal Contamination of Water, Soil, and Vegetables

    Directory of Open Access Journals (Sweden)

    Amir Waseem

    2014-01-01

    Full Text Available Trace heavy metals, such as arsenic, cadmium, lead, chromium, nickel, and mercury, are important environmental pollutants, particularly in areas with high anthropogenic pressure. In addition to these metals, copper, manganese, iron, and zinc are also important trace micronutrients. The presence of trace heavy metals in the atmosphere, soil, and water can cause serious problems to all organisms, and the ubiquitous bioavailability of these heavy metal can result in bioaccumulation in the food chain which especially can be highly dangerous to human health. This study reviews the heavy metal contamination in several areas of Pakistan over the past few years, particularly to assess the heavy metal contamination in water (ground water, surface water, and waste water, soil, sediments, particulate matter, and vegetables. The listed contaminations affect the drinking water quality, ecological environment, and food chain. Moreover, the toxicity induced by contaminated water, soil, and vegetables poses serious threat to human health.

  13. Heavy metal concentrations in marine green, brown, and red seaweeds from coastal waters of Yemen, the Gulf of Aden

    Science.gov (United States)

    Al-Shwafi, Nabil A.; Rushdi, Ahmed I.

    2008-08-01

    The purpose of this study was to investigate the concentration levels of heavy metals in different species of the main three marine algal divisions from the Gulf of Aden coastal waters, Yemen. The divisions included Chlorophyta—green plants ( Halimeda tuna, Rhizoclonium kochiamum, Caldophora koiei, Enteromorpha compressa, and Caulerpa racemosa species), Phaeophyta—brown seaweeds ( Padina boryana, Turbinaria elatensis, Sargassum binderi, Cystoseira myrica, and Sargassum boveanum species), and Rhodophyta—red seaweeds ( Hypnea cornuta, Champia parvula, Galaxaura marginate, Laurencia paniculata, Gracilaria foliifere, and species). The heavy metals, which included cadmium (Cd), cobalt (Co), copper (Cu), chromium (Cr), Iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), zinc (Zn), and vanadium (V) were measured by Atomic Absorption Spectrophotometer (AAs). The concentrations of heavy metals in all algal species are in the order of Fe >> Cu > Mn > Cr > Zn > Ni > Pb > Cd > V > Co. The results also showed that the uptake of heavy metals by different marine algal divisions was in the order of Chlorophyta > Phaeophyta > Rhodophyta. These heavy metals were several order of magnitude higher than the concentrations of the same metals in seawater. This indicates that marine alga progressively uptake heavy metals from seawater.

  14. Neutron moderation in heavy water

    International Nuclear Information System (INIS)

    Assis, J.T. de.

    1980-03-01

    The calculation of the energetic spectrum of thermic neutrons in heavy water, according to the models of the differential cross section; is presented. Simplifications in the Butler model are suggested for the diminution of computer time. The results obtained are compared with experimental data and with the Brown - St.John model. This calculation has been done in 30 energy groups and within our limit of precision, the results with the models and simplifications present satisfactory values, allowing its inclusion in reactor codes. (Author) [pt

  15. Reactivity requirements and safety systems for heavy water reactors

    International Nuclear Information System (INIS)

    Kati, S.L.; Rustagi, R.S.

    1977-01-01

    The natural uranium fuelled pressurised heavy water reactors are currently being installed in India. In the design of nuclear reactors, adequate attention has to be given to the safety systems. In recent years, several design modifications having bearing on safety, in the reactor processes, protective and containment systems have been made. These have resulted either from new trends in safety and reliability standards or as a result of feed-back from operating reactors of this type. The significant areas of modifications that have been introduced in the design of Indian PHWR's are: sophisticated theoretical modelling of reactor accidents, reactivity control, two independent fast acting systems, full double containment and improved post-accident depressurisation and building clean-up. This paper brings out the evolution of design of safety systems for heavy water reactors. A short review of safety systems which have been used in different heavy water reactors, of varying sizes, has been made. In particular, the safety systems selected for the latest 235 MWe twin reactor unit station in Narora, in Northern India, have been discussed in detail. Research and Development efforts made in this connection are discussed. The experience of design and operation of the systems in Rajasthan and Kalpakkam reactors has also been outlined

  16. Heavy-Water Power Reactors. Proceedings Of A Symposium

    International Nuclear Information System (INIS)

    1968-01-01

    Proceedings of a Symposium organized by the IAEA and held in Vienna, 11-15 September 1967. The timeliness of the meeting was underlined by the large gathering of over 225 participants from 28 countries and three international organizations. Contents: Experience with heavy-water power and experimental reactors and projects (14 papers); New and advanced power reactor designs and concepts (8 papers); Development programmes and thorium cycle (9 papers); Economics and prospects of heavy-water power reactors (7 papers); Physics and fuel management (8 papers); Fuels (5 papers); Safety, control and engineering (6 papers); Panel discussion. Except for one Russian paper, which is published in English, each paper is in its original language (49 English and 8 French) and is preceded by an abstract in English with a second one in the original language if this is not English. Discussions are in English. (author)

  17. Heavy-Water Power Reactors. Proceedings Of A Symposium

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1968-04-15

    Proceedings of a Symposium organized by the IAEA and held in Vienna, 11-15 September 1967. The timeliness of the meeting was underlined by the large gathering of over 225 participants from 28 countries and three international organizations. Contents: Experience with heavy-water power and experimental reactors and projects (14 papers); New and advanced power reactor designs and concepts (8 papers); Development programmes and thorium cycle (9 papers); Economics and prospects of heavy-water power reactors (7 papers); Physics and fuel management (8 papers); Fuels (5 papers); Safety, control and engineering (6 papers); Panel discussion. Except for one Russian paper, which is published in English, each paper is in its original language (49 English and 8 French) and is preceded by an abstract in English with a second one in the original language if this is not English. Discussions are in English. (author)

  18. Heavy metals in water, sediments and submerged macrophytes in ponds around the Dianchi Lake, China.

    Science.gov (United States)

    Wang, Zhixiu; Yao, Lu; Liu, Guihua; Liu, Wenzhi

    2014-09-01

    Through retaining runoff and pollutants such as heavy metals from surrounding landscapes, ponds around a lake play an important role in mitigating the impacts of human activities on lake ecosystems. In order to determine the potential for heavy metal accumulation of submerged macrophytes, we investigated the concentrations of 10 heavy metals (i.e., As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in water, sediments, and submerged macrophytes collected from 37 ponds around the Dianchi Lake in China. Our results showed that both water and sediments of these ponds were polluted by Pb. Water and sediments heavy metal concentrations in ponds received urban and agricultural runoff were not significantly higher than those in ponds received forest runoff. This result indicates that a large portion of heavy metals in these ponds may originate from atmospheric deposition and weathering of background soils. Positive relationships were found among heavy metal concentrations in submerged macrophytes, probably due to the coaccumulation of heavy metals. For most heavy metals, no significant relationships were found between submerged macrophytes and their water and sediment environments. The maximum concentrations of Cr, Fe and Ni in Ceratophyllum demersum were 4242, 16,429 and 2662mgkg(-1), respectively. The result suggests that C. demersum is a good candidate species for removing heavy metals from polluted aquatic environments. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. A Management Strategy for the Heavy Water Reflector Cooling System of HANARO Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jung, H. S.; Park, Y. C.; Lim, S. P. (and others)

    2007-11-15

    Heavy water is used as the reflector and the moderator of the HANARO research reactor. After over 10 years operation since first criticality in 1995 there arose some operational issues related with the tritium. A task force team(TFT) has been operated for 1 year since September 2006 to study and deduce resolutions of the issues concerning the tritium and the degradation of heavy water in the HANARO reflector system. The TFT drew many recommendations on the hardware upgrade, tritium containing air control, heavy water quality management, waste management, and tritium measurement system upgrade.

  20. Pyrolized biochar for heavy metal adsorption

    Science.gov (United States)

    Removal of copper and lead metal ions from water using pyrolized plant materials. Method can be used to develop a low cost point-of-use device for cleaning contaminated water. This dataset is associated with the following publication:DeMessie, B., E. Sahle-Demessie , and G. Sorial. Cleaning Water Contaminated With Heavy Metal Ions Using Pyrolyzed Banana Peel Adsorbents. Separation Science and Technology. Marcel Dekker Incorporated, New York, NY, USA, 50(16): 2448-2457, (2015).

  1. The effect of plant water storage on water fluxes within the coupled soil-plant system.

    Science.gov (United States)

    Huang, Cheng-Wei; Domec, Jean-Christophe; Ward, Eric J; Duman, Tomer; Manoli, Gabriele; Parolari, Anthony J; Katul, Gabriel G

    2017-02-01

    In addition to buffering plants from water stress during severe droughts, plant water storage (PWS) alters many features of the spatio-temporal dynamics of water movement in the soil-plant system. How PWS impacts water dynamics and drought resilience is explored using a multi-layer porous media model. The model numerically resolves soil-plant hydrodynamics by coupling them to leaf-level gas exchange and soil-root interfacial layers. Novel features of the model are the considerations of a coordinated relationship between stomatal aperture variation and whole-system hydraulics and of the effects of PWS and nocturnal transpiration (Fe,night) on hydraulic redistribution (HR) in the soil. The model results suggest that daytime PWS usage and Fe,night generate a residual water potential gradient (Δψp,night) along the plant vascular system overnight. This Δψp,night represents a non-negligible competing sink strength that diminishes the significance of HR. Considering the co-occurrence of PWS usage and HR during a single extended dry-down, a wide range of plant attributes and environmental/soil conditions selected to enhance or suppress plant drought resilience is discussed. When compared with HR, model calculations suggest that increased root water influx into plant conducting-tissues overnight maintains a more favorable water status at the leaf, thereby delaying the onset of drought stress. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  2. On the basic substances used in the separation process by isotope exchange H2S - H2O, at two temperatures, in view of producing heavy water

    International Nuclear Information System (INIS)

    Popescu, V.

    1977-01-01

    In view of producing heavy water, the influence of the deuterium proportion in the basic substances, on the efficiency of the isotope exchange process H 2 S - H 2 O for two temperatures was studied. Heavy water is extracted from ordinary water and concentrated from 0.014 per cent to 5-15 per cent D 2 O by isotope bithermal exchange with the hydrogen sulphite. Theoretical and experimental research was carried out in laboratories and then applied on a pilot plant by designing and testing a drying equipment for hydrogen sulphite. The maximum H 2 S concentration rose to 99.84 per cent. The purity of the hydrogen sulphite resulting from the pilot plant, as well as the optimization of the installation for producing H 2 S depending on the deuterium distribution, make sure that the two methods for the preparation of sodium sulphite and hydrogen sulphite can be applied in industry. (author)

  3. Evaluation of Heavy Metal Exposure to Soil and Paddy Plant around the Closed Municipal Solid Waste Landfill: Case Study at Gunung Tugel Landfill, Banyumas-Central Java

    Science.gov (United States)

    Kasam; Rahmawati, Suphia; Mulya Iresha, Fajri; Wacano, Dhandhun; Farida Fauziah, Ida; Afif Amrullah, Muhammad

    2018-01-01

    This work was focused on assessing the exposure of heavy metal from closed municipal solid waste (MSW) landfill on soil and paddy plants. This study aimed to determine heavy metal content whether at the soil in the around Gunung Tugel landfill included and accumulated in the paddy plant tissues. The investigated metals include chromium (Cr), copper (Cu), cadmium (Cd), iron (Fe), and zinc (Zn). The samples were acid-digested before the desired elements were measured using Atomic Absorption Spectrophotometry (AAS). The results are presented as distribution map of the landfill area based on the total heavy metals content distribution in the soil and paddy plants. The samples shown that the concentrations of heavy metals around Gunung Tugel landfill are 6.27-34.71 mg/kg, 0.17-0.42 mg/kg, 28.29-48.69 mg/kg, 18,997.26-32,572.29 mg/kg, 342.74-834.49 mg/kg, 136.10-290.14 mg/kg at the top soil and 0.00-1.70 mg/kg, 0.00-0.26 mg/kg, 0.79-10.46 mg/kg, 13.88-61.46 mg/kg, 18.79-50.56 mg/kg, 87.27-273.22 mg/kg at the paddy for Cr, Cd, Cu, Fe, Mn, and Zn respectively. According to the results, The Gunung Tugel landfill is not a direct source of heavy metal pollution at paddy plant in the landfill area, but through surface water and soil media. Rainfall around landfill is quite high ie more 2000 mm/year of rainfall and soil permeability is 1.0 cm/sec.

  4. An integrated heavy metal emission inventory in Alsace and Baden-Wurtemberg

    International Nuclear Information System (INIS)

    Veaux, Ch.; Zundel, T.; Rentz, O.

    1997-01-01

    The emissions of the heavy metals As, Cd, Cr, Cu, Hg, Ni, Pb, Se, V, and Zn into the air, water and by-products, caused by stationary combustion plants in Baden-Wurtemberg (Germany) and Alsace (France) aRe assessed. The main emphasis of the study is on the development of an adequate, process specific tool allowing to determine multi-media heavy metal emissions by bottom ash or slag, filter ash, by-products of the flue gas desulfurization device (FGD by-products), and flue gas from the use of fossil fuels in Baden-Wurtemberg and Alsace. The heavy metal mass streams are analysed systematically with regard to fuel composition, boiler type, operation mode and flue gas treatment devices to define representative plants with regard to the partitioning of heavy metal streams. For these representative plants, partition factors, which characterise the distribution of heavy metals streams. The emission factors are derived from the partition factors and the heavy concentrations in the fuels used. Then, the emission factors are associated with data on emission sources referring to the configuration of combustion installations and activity data (annual consumption of fuel) to assess the heavy metal emissions in the study region. Heavy metal emissions through bottom ash, filter ash, FGD by-products and flue gas as well as heavy metal deposition in plants are assessed for the sectors 'public power plants', industrial combustion' and 'domestic heating' for the base year 1992. The results are available for Baden-Wurtemberg and Alsace for each heavy metal, sector, emission pathway, and combustion technique. (authors)

  5. To study the recovery of L-Cysteine using halloysite nanotubes after heavy metal removal

    Science.gov (United States)

    Thakur, Juhi

    2016-04-01

    Industrial wastes are a major source of soil and water pollution that originate from mining industries, chemical industries, metal processing industries, etc. These wastes consist of a variety of chemicals including phenolics, heavy metals, etc. Use of industrial effluent and sewage sludge on agricultural land has become a common practice in the world which results in these toxic metals being transferred and ultimately concentrate in plant tissues from water and the soil. The metals that get accumulated, prove detrimental to plants themselves and may also cause damage to the healths of animals as well as man. This is because the heavy metals become toxins above certain concentrations, over a narrow range. As a further matter, these metals negatively affect the natural microbial populations as well, that leads to the disruption of fundamental ecological processes. However, many techniques and methods have been advanced to clear the heavy metal polluted soils and waters. One important method is by removing heavy metals with the help of amino acids like L-Cysteine and L-Penicillamine. But also, economy of removal of pollutant heavy metals from soils and waters is a major concern. Present study helps in decreasing the cost for large-scale removal of heavy metals from polluted water by recovering the amino acid (L-Cysteine) after removal of nickel (Ni+2) at a fixed pH, by binding the Ni+2 with halloysite nanotubes(HNT), so that L-Cysteine can be reused again for removal of heavy metals.

  6. Accelerator driven heavy water blanket on circulating fuel

    International Nuclear Information System (INIS)

    Kazaritsky, V.D.; Blagovolin, P.P.; Mladov, V.R.; Okhlopkov, M.L.; Batyaev, V.F.; Stepanov, N.V.; Seliverstov, V.V.

    1997-01-01

    A conceptual design of a heavy water blanket with circulating fuel for an accelerator driven transmutation system is described. The hybrid system consists of a high-current linear accelerator of protons and 4 targets, each placed inside a subcritical blanket

  7. Heavy metal recovery from contaminated biomass ashes by chemical leaching, bioleaching and biosorption

    International Nuclear Information System (INIS)

    Pirker, K.

    2000-01-01

    Ashes from biomass combustion plants contain plant nutrients which makes their application as fertilizers economically interesting. The possibility of recycling the ash can be looked upon as a contribution to obtain a sustainable energy utilization from biomass. The ash contains heavy metals which have to be removed. The possibility of decontaminating the ash by chemical and biological leaching was investigated. The leaching capacity of commercially available organic and inorganic acids and of citric acid produced by the fungus Penicillium simplicissimus were determined. A process for heavy metal recovery from biomass ashes consisting of four steps was designed. All environmentally relevant heavy metals (except lead) were removed from contaminated biomass ashes by chemical leaching. The heavy metals were recovered and enriched by precipitation and subsequent biosorption. Inactivated bacteria and fungi were used as biosorbents. The overall costs and the washing-out of plant nutrients from the ashes by chemical leaching were drawbacks of the metal recovering process. Biosorption in combination with existing processes of waste water treatment would offer another promising possibility for achieving the low Austrian limiting values for heavy metals in waste water. (author)

  8. Assessing potential dietary toxicity of heavy metals in selected vegetables and food crops.

    Science.gov (United States)

    Islam, Ejaz ul; Yang, Xiao-e; He, Zhen-li; Mahmood, Qaisar

    2007-01-01

    Heavy metals, such as cadmium, copper, lead, chromium and mercury, are important environmental pollutants, particularly in areas with high anthropogenic pressure. Their presence in the atmosphere, soil and water, even in traces can cause serious problems to all organisms, and heavy metal bioaccumulation in the food chain especially can be highly dangerous to human health. Heavy metals enter the human body mainly through two routes namely: inhalation and ingestion, ingestion being the main route of exposure to these elements in human population. Heavy metals intake by human populations through food chain has been reported in many countries. Soil threshold for heavy metal toxicity is an important factor affecting soil environmental capacity of heavy metal and determines heavy metal cumulative loading limits. For soil-plant system, heavy metal toxicity threshold is the highest permissible content in the soil (total or bioavailable concentration) that does not pose any phytotoxic effects or heavy metals in the edible parts of the crops does not exceed food hygiene standards. Factors affecting the thresholds of dietary toxicity of heavy metal in soil-crop system include: soil type which includes soil pH, organic matter content, clay mineral and other soil chemical and biochemical properties; and crop species or cultivars regulated by genetic basis for heavy metal transport and accumulation in plants. In addition, the interactions of soil-plant root-microbes play important roles in regulating heavy metal movement from soil to the edible parts of crops. Agronomic practices such as fertilizer and water managements as well as crop rotation system can affect bioavailability and crop accumulation of heavy metals, thus influencing the thresholds for assessing dietary toxicity of heavy metals in the food chain. This paper reviews the phytotoxic effects and bioaccumulation of heavy metals in vegetables and food crops and assesses soil heavy metal thresholds for potential dietary

  9. Adsorption of heavy metals ions on portulaca oleracea plants

    International Nuclear Information System (INIS)

    Naqvi, R.R.

    2005-01-01

    The aim of this study is to report the ability of portulaca oleracea (Fershi in Urdu) biomass grown in uncontaminated soils to adsorb or uptake lead, cadmium, arsenic, cobalt and copper from aqueous solutions. In order to help understand the metal binding mechanism, laboratory experiments performance to determine optimal binding, and binding capacity for each of the above mentioned metals. These experiments were carried out for the mass of crushed portulaca stems. Portulaca is a plant that grows abundantly in temperature climate in the area of Quetta Balochistan. It has reddish stem and thick succulent leaves. This plant has been found to be good adsorbent for heavy metals ions. (author)

  10. Heavy Metal Content in Selected Flavouring Plants and in Ultra-Basic Soil of Felda Rokan Barat, Negeri Sembilan, Malaysia

    International Nuclear Information System (INIS)

    Sahibin Abdul Rahim; Wan Mohd Razi Idris; Zulfahmi Ali Rahman; Tukimat Lihan; Ramlan Omar; Yan, L.K.

    2012-01-01

    A study was carried out at an ultra basic soil area in Felda Rokan Barat (FRB), Negeri Sembilan. Twenty plants of samples namely chili, turmeric, pandan and lemon grass were collected randomly for the determination of heavy metal contents such as Fe, Cd, Co, Cu, Mn, Ni, Pb, Cr and Zn. Heavy metals in plants were extracted by wet digestion method, whereas available and resistant heavy metals in soil were extracted by sequential extraction. Total heavy metals content in the soil were obtained by summation of resistant and available heavy metals. Heavy metals content in soil and plant extract were determined by using the Flame Atomic Absorption Spectrophotometer (FAAS). Results showed that Fe was the dominant composition in soil in the study area while Cd concentration was very low with values of < 10 mg/ kg. The range of heavy metals concentration in soils were Fe (2618.4 to 4248 mg/ kg), Mn (240.9 to 741.9 mg/ kg), Zn (81.9 to 324.8 mg/ kg), Cr (46.8 to 438.7 mg/ kg), Cu (15.7 to 81.7 mg/ kg), Pb (14.9 to 116.8 mg/ kg), Ni (10.1 to 545.6 mg/ kg), Cd (5.6 to 10.6 mg/ kg) dan Co (0.8 to 126.1 mg/ kg). Available Fe recorded the highest value in all of the plant substrates followed by Mn, Zn, Pb, Ni, Cr, Cu, Co and Cd. Based on percentage of availability Mn, Pb and Zn are considered most available by plant with availability percentage of 8 to 10 %. Concentration of Fe, Mn, Ni and Zn were high in all parts of plants compared to the other metals. The value of biological absorption coefficient (BAC) in chili, turmeric, pandan and lemon grass were in the range of 0.02-0.36, 0.03-0.41, 0.03-0.63 and 0.03-1.15, respectively. It can be concluded that the uptake of heavy metals by plants were normal even though the heavy metals concentration in the ultra basic soil was high. (author)

  11. Concentration of Heavy Metals in Drinking Water from Urban Areas ...

    African Journals Online (AJOL)

    Bheema

    drinking water treatment practices in the areas, which in turn have important human health implications. This study, therefore, recommends the government and other responsible authorities to take appropriate corrective measures. Key words: Drinking water quality, Heavy metals, Maximum admissible limit, World health.

  12. Silica coated magnetite nanoparticles for removal of heavy metal ions from polluted waters

    CERN Document Server

    Dash, Monika

    2013-01-01

    Magnetic removal of Hg2+ and other heavy metal ions like Cd2+, Pb2+ etc. using silica coated magnetite particles from polluted waters is a current topic of active research to provide efficient water recycling and long term high quality water. The technique used to study the bonding characteristics of such kind of nanoparticles with the heavy metal ions is a very sensitive hyperfine specroscopy technique called the perturbed angular correlation technique (PAC).

  13. Heavy metal pollution in immobile and mobile components of lentic ecosystems-a review.

    Science.gov (United States)

    Meena, Ramakrishnan Anu Alias; Sathishkumar, Palanivel; Ameen, Fuad; Yusoff, Abdull Rahim Mohd; Gu, Feng Long

    2018-02-01

    With growing population and urbanization, there is an increasing exploitation of natural resources, and this often results to environmental pollution. In this review, the levels of heavy metal in lentic compartments (water, sediment, fishes, and aquatic plants) over the past two decades (1997-2017) have been summarized to evaluate the current pollution status of this ecosystem. In all the compartments, the heavy metals dominated are zinc followed by iron. The major reason could be area mineralogy and lithogenic sources. Enormous quantity of metals like iron in estuarine sediment is a very natural incident due to the permanently reducing condition of organic substances. Contamination of cadmium, lead, and chromium was closely associated with anthropogenic origin. In addition, surrounding land use and atmospheric deposition could have been responsible for substantial pollution. The accumulation of heavy metals in fishes and aquatic plants is the result of time-dependent deposition in lentic ecosystems. Moreover, various potential risk assessment methods for heavy metals were discussed. This review concludes that natural phenomena dominate the accumulation of essential heavy metals in lentic ecosystems compared to anthropogenic sources. Amongst other recent reviews on heavy metals from other parts of the world, the present review is executed in such a way that it explains the presence of heavy metals not only in water environment, but also in the whole of the lentic system comprising sediment, fishes, and aquatic plants.

  14. Heavy water production by alkaline water electrolysis

    International Nuclear Information System (INIS)

    Kamath, Sachin; Sandeep, K.C.; Bhanja, Kalyan; Mohan, Sadhana; Sugilal, G.

    2014-01-01

    Several heavy water isotope production processes are reported in literature. Water electrolysis in combination with catalytic exchange CECE process is considered as a futuristic process to increase the throughput and reduce the cryogenic distillation load but the application is limited due to the high cost of electricity. Any improvement in the efficiency of electrolyzers would make this process more attractive. The efficiency of alkaline water electrolysis is governed by various phenomena such as activation polarization, ohmic polarization and concentration polarization in the cell. A systematic study on the effect of these factors can lead to methods for improving the efficiency of the electrolyzer. A bipolar and compact type arrangement of the alkaline water electrolyzer leads to increased efficiency and reduced inventory in comparison to uni-polar tank type electrolyzers. The bipolar type arrangement is formed when a number of single cells are stacked together. Although a few experimental studies have been reported in the open literature, CFD simulation of a bipolar compact alkaline water electrolyzer with porous electrodes is not readily available.The principal aim of this study is to simulate the characteristics of a single cell compact electrolyzer unit. The simulation can be used to predict the Voltage-Current Density (V-I) characteristics, which is a measure of the efficiency of the process.The model equations were solved using COMSOL multi-physics software. The simulated V-I characteristic is compared with the experimental data

  15. Process engineering considerations in the design of the water treatment plant for the Rum Jungle rehabilitation project

    International Nuclear Information System (INIS)

    Ackland, M.C.

    1983-01-01

    The Rum Jungle rehabilitation programme includes the treatment of around 4 million cubic metres of water that has been polluted by previous treatment operations and acidic seepage containing heavy metal salts from slowly oxidising overburden dumps. The water to be treated is of low pH and contains high sulphate levels. Project rehabilitation criteria and the basic chemistry of metal salts in solution were considered in arriving at the final process design. In order to achieve a cost effective plant design, the process was translated into a flow sheet that used unit operations that are more typical of the extractive metallurgical than the traditional water treatment industry. Consideration of the unit operations and the operating aspects of the plant are discussed

  16. Performance of refractometry in quantitative estimation of isotopic concentration of heavy water in nuclear reactor

    International Nuclear Information System (INIS)

    Dhole, K.; Roy, M.; Ghosh, S.; Datta, A.; Tripathy, M.K.; Bose, H.

    2013-01-01

    Highlights: ► Rapid analysis of heavy water samples, with precise temperature control. ► Entire composition range covered. ► Both variations in mole and wt.% of D 2 O in the heavy water sample studied. ► Standard error of calibration and prediction were estimated. - Abstract: The method of refractometry has been investigated for the quantitative estimation of isotopic concentration of heavy water (D 2 O) in a simulated water sample. Feasibility of refractometry as an excellent analytical technique for rapid and non-invasive determination of D 2 O concentration in water samples has been amply demonstrated. Temperature of the samples has been precisely controlled to eliminate the effect of temperature fluctuation on refractive index measurement. The method is found to exhibit a reasonable analytical response to its calibration performance over the purity range of 0–100% D 2 O. An accuracy of below ±1% in the measurement of isotopic purity of heavy water for the entire range could be achieved

  17. Heavy metal pollution in drinking water - a global risk for human ...

    African Journals Online (AJOL)

    Water resources in the world have been profoundly influenced over the last years by human activities, whereby the world is currently facing critical water supply and drinking water quality problems. In many parts of the world heavy metal (HM) concentrations in drinking water are higher than some international guideline ...

  18. Deuterium content on surface waters VI to X Chile regions

    International Nuclear Information System (INIS)

    Aravena C, R; Pollastri J, A.; Suzuki S, O.

    1984-01-01

    One important parameter on any sitting study for a heavy water plant installation is the deuterium content of the feed water. Deuterium data on surface waters from differents areas located in the south of Chile, are presented. These results allow to idently some potential areas for a future heavy water plant. One of these areas, Lago Llanquihue, was sampled more in detail to study the vertical distribution and spatial variations. (Author)

  19. Monitoring of Hazardous Inorganic Pollutants and Heavy Metals in Potable Water at the Source of Supply and Consumers end of a Tropical Urban Municipality

    International Nuclear Information System (INIS)

    Shah, A. B.; Singh, R. P.

    2016-01-01

    River water is not only an indispensable source for irrigation but also plays a vital role for drinking water supply for most of the urban municipalities. Water from rivers is pumped at specific sites and after treatment at municipal water treatment plants supplied as domestic potable water supply. The present study was undertaken to assess the suitability of Gomti river water at Gaughat being used as the source of water supply for Lucknow city and to evaluate post-treatment potable water quality at the consumer end by monitoring the levels of inorganic pollutants (nitrate, nitrite, ammonium and phosphate) and heavy metals. Municipal water supply at Gaughat showed marked variations in the levels of p H (7.13-8.63) and electrical conductivity (375.66-571.67μS/cm). The amount of nitrate, nitrite, ammonium and phosphate was observed 26.25, 0.082, 6.9 and 1.82 mg/l respectively at Gaughat. Also, the levels of heavy metals in the municipal water source at Gaughat varied significantly for Fe (0.33-1.65 mg/l), Cu (0.077-0.108 mg/l), Cd (0.03-0.052 mg/l), Pb (0.68-0.96 mg/l) and Cr (0.036-0.065 mg/l). Water at the user end was also contaminated as the concentration of analysed inorganic pollutants and heavy metals were correspondingly higher than observed at the source. While comparing potable water at the user end of Lucknow municipality with the BIS (Drinking Water Specifications) and WHO standards for drinking water, the concentration of all studied heavy metals and other inorganic contaminants were much above the permissible levels, thus posing a serious threat to the public health.

  20. DEGRADATION EVALUATION OF HEAVY WATER DRUMS AND TANKS

    Energy Technology Data Exchange (ETDEWEB)

    Mickalonis, J.; Vormelker, P.

    2009-07-31

    Heavy water with varying chemistries is currently being stored in over 6700 drums in L- and K-areas and in seven tanks in L-, K-, and C-areas. A detailed evaluation of the potential degradation of the drums and tanks, specific to their design and service conditions, has been performed to support the demonstration of their integrity throughout the desired storage period. The 55-gallon drums are of several designs with Type 304 stainless steel as the material of construction. The tanks have capacities ranging from 8000 to 45600 gallons and are made of Type 304 stainless steel. The drums and tanks were designed and fabricated to national regulations, codes and standards per procurement specifications for the Savannah River Site. The drums have had approximately 25 leakage failures over their 50+ years of use with the last drum failure occurring in 2003. The tanks have experienced no leaks to date. The failures in the drums have occurred principally near the bottom weld, which attaches the bottom to the drum sidewall. Failures have occurred by pitting, crevice and stress corrosion cracking and are attributable, in part, to the presence of chloride ions in the heavy water. Probable degradation mechanisms for the continued storage of heavy water were evaluated that could lead to future failures in the drum or tanks. This evaluation will be used to support establishment of an inspection plan which will include susceptible locations, methods, and frequencies for the drums and tanks to avoid future leakage failures.