Measurement of the thickness of a target deposited in a substrate

International Nuclear Information System (INIS)

Martinez Q, E.; Aguilera, E.F.

1990-12-01

Being based on the Elastic scattering and in the Energy losses that suffer a projectile to the interacting with the matter, a method that allows to determine the thickness of a target deposited in a more heavy substrate is presented. The obtained results are consistent with that waited and the derived errors of the method are small. The used technique allows to reduce in considerable form the systematic errors coming from the calibration of the equipment. It is considered that this method is applicable in an interval of thickness quite wide and for many materials since it is only necessary to choose the projectile type and the energy of the same one appropriately. (Author)

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

Water equivalent thickness values of materials used in beams of protons, helium, carbon and iron ions.

Science.gov (United States)

Zhang, Rui; Taddei, Phillip J; Fitzek, Markus M; Newhauser, Wayne D

2010-05-07

Heavy charged particle beam radiotherapy for cancer is of increasing interest because it delivers a highly conformal radiation dose to the target volume. Accurate knowledge of the range of a heavy charged particle beam after it penetrates a patient's body or other materials in the beam line is very important and is usually stated in terms of the water equivalent thickness (WET). However, methods of calculating WET for heavy charged particle beams are lacking. Our objective was to test several simple analytical formulas previously developed for proton beams for their ability to calculate WET values for materials exposed to beams of protons, helium, carbon and iron ions. Experimentally measured heavy charged particle beam ranges and WET values from an iterative numerical method were compared with the WET values calculated by the analytical formulas. In most cases, the deviations were within 1 mm. We conclude that the analytical formulas originally developed for proton beams can also be used to calculate WET values for helium, carbon and iron ion beams with good accuracy.

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.)

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.)

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)

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

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

Implosion of multilayered cylindrical targets driven by intense heavy ion beams.

Science.gov (United States)

Piriz, A R; Portugues, R F; Tahir, N A; Hoffmann, D H H

2002-11-01

An analytical model for the implosion of a multilayered cylindrical target driven by an intense heavy ion beam has been developed. The target is composed of a cylinder of frozen hydrogen or deuterium, which is enclosed in a thick shell of solid lead. This target has been designed for future high-energy-density matter experiments to be carried out at the Gesellschaft für Schwerionenforschung, Darmstadt. The model describes the implosion dynamics including the motion of the incident shock and the first reflected shock and allows for calculation of the physical conditions of the hydrogen at stagnation. The model predicts that the conditions of the compressed hydrogen are not sensitive to significant variations in target and beam parameters. These predictions are confirmed by one-dimensional numerical simulations and thus allow for a robust target design.

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.

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

Design of the solid target structure and the study on the coolant flow distribution in the solid target using the 2-dimensional flow analysis

International Nuclear Information System (INIS)

Haga, Katsuhiro; Terada, Atsuhiko; Ishikura, Shuichi; Teshigawara, Makoto; Kinoshita, Hidetaka; Kobayashi, Kaoru; Kaminaga, Masaki; Hino, Ryutaro; Susuki, Akira

1999-11-01

A solid target cooled by heavy water is presently under development under the Neutron Science Research Project of the Japan Atomic Energy Research Institute (JAERI). Target plates of several millimeters thickness made of heavy metal are used as the spallation target material and they are put face to face in a row with one to two millimeters gaps in between though which heavy water flows, as the coolant. Based on the design criteria regarding the target plate cooling, the volume percentage of the coolant, and the thermal stress produced in the target plates, we conducted thermal and hydraulic analysis with a one dimensional target plate model. We choosed tungsten as the target material, and decided on various target plate thicknesses. We then calculated the temperature and the thermal stress in the target plates using a two dimensional model, and confirmed the validity of the target plate thicknesses. Based on these analytical results, we proposed a target structure in which forty target plates are divided into six groups and each group is cooled using a single pass of coolant. In order to investigate the relationship between the distribution of the coolant flow, the pressure drop, and the coolant velocity, we conducted a hydraulic analysis using the general purpose hydraulic analysis code. As a result, we realized that an uniform coolant flow distribution can be achieved under a wide range of flow velocity conditions in the target plate cooling channels from 1 m/s to 10 m/s. The pressure drop along the coolant path was 0.09 MPa and 0.17 MPa when the coolant flow velocity was 5 m/s and 7 m/s respectively, which is required to cool the 1.5 MW and 2.5 MW solid targets. (author)

Manual for target thickness measurement by alpha particle irradiation

International Nuclear Information System (INIS)

Dias, J.F.; Martins, M.N.

1990-04-01

A system is described for thin-target thickness measurement through the alpha particle energy loss when them traverse the target. It is also described the program used in the analysis of the target thickness. (L.C.) [pt

Measurements of neutron spectra produced from a thick iron target bombarded with 1.5 GeV protons

International Nuclear Information System (INIS)

Meigo, Shin-ichiro; Takada, Hiroshi

2001-01-01

For validation of calculation codes which are employed in the design of accelerator facilities, spectra of neutrons produced from a thick iron target bombarded with 1.5-GeV protons were measured. The calculated results with NMTC/JAM were compared with the present experimental results. It is found the NMTC/JAM generally shows in good agreement with experiment. Furthermore, the calculation gives good agreement with the experiment for the energy region 20-80 MeV, whereas the NMTC/JAM gives 50% of the experimental data for the heavy nuclide target such as lead and tungsten target. (author)

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.

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

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)

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)

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

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.)

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.)

Transfer products from the reactions of heavy ions with heavy nuclei

International Nuclear Information System (INIS)

Thomas, K.E. III.

1979-11-01

Production of nuclides heavier than the target from 86 Kr- and 136 Xe-induced reactions with 181 Ta and 238 U was investigated. Attempts were made to produce new neutron-excess Np and Pu isotopes by the deep inelastic mechanism. No evidence was found for 242 Np or 247 Pu. Estimates were made for the production of 242 Np, 247 Pu, and 248 Am from heavy-ion reactions with uranium targets. Comparisons of reactions of 86 Kr and 136 Xe ions with thick 181 Ta targets and 86 Kr, 136 Xe and 238 U ions with thick 238 U targets indicate that the most probable products are not dependent on the projectile. The most probable products can be predicted by the equation Z - Z/sub target/ = 0.43 (A - A/sub target/) + 1.0. The major effect of the projectile is the magnitude of the production cross section of the heavy products. Based on these results, estimates are made of the most probable mass of element 114 produced from heavy-ion reactions with 248 Cm and 254 Es targets. These estimates give the mass number of element 114 as approx. 287 if produced in heavy-ion reactions with these very heavy targets. Excitation functions of gold and bismuth isotopes arising from 86 Kr- and 136 Xe-induced reactions with thin 181 Ta targets were measured. These results indicate that the shape and location (in Z and A above the target) of the isotopic distributions are not strongly dependent on the projectile incident energy. Also, the nuclidic cross sections are found to increase with an increase in projectile energy to a maximum at approximately 1.4 to 1.5 times the Coulomb barrier. Above this maximum, the nuclidic cross sections are found to decrease with an increase in projectile energy. This decrease in cross section is believed to be due to fission of the heavy products caused by high excitation energy and angular momentum. 111 references, 39 figures, 34 tables

Direct-driven target implosion in heavy ion fusion

International Nuclear Information System (INIS)

Noguchi, K.; Suzuki, T.; Kurosaki, T.; Barada, D.; Kawata, S.; Ma, Y. Y.; Ogoyski, A. I.

2016-01-01

In inertial confinement fusion, the driver beam illumination non-uniformity leads a degradation of fusion energy output. A fuel target alignment error would happen in a fusion reactor; the target alignment error induces heavy ion beam illumination non-uniformity on a target. On the other hand, heavy ion beam accelerator provides a capability to oscillate a beam axis with a high frequency. The wobbling beams may provide a new method to reduce or smooth the beam illumination non-uniformity. First we study the effect of driver irradiation non-uniformity induced by the target alignment error (dz) on the target implosion. We found that dz should be less than about 130 μm for a sufficient fusion energy output. We also optimize the wobbling scheme. The spiral wobbling heavy ion beams would provide a promissing scheme to the uniform beam illumination. (paper)

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.)

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)

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

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

Separation factor dependence upon cathode material for tritium separation from heavy water by electrolysis

International Nuclear Information System (INIS)

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

2002-01-01

Using three cathode materials, i.e. carbon (C), stainless steel (SUS), and nickel (Ni), tritium was separated from heavy water by electrolysis, and the separation factors were compared. To separate hydrogen isotopes, heavy water was electrolyzed by an electrolysis device with a solid polymer electrode (SPE), which needed no electrolyte additives for electrolysis. The anode was made of 3 mm thickness of a sintered porous titanium plate covered with iridium oxide. The cathode was made of the same thickness of a sintered porous carbon, stainless steel, or nickel plate. Heavy water or light water spiked with tritiated water was electrolyzed 20 A x 60 min with the electrolysis cell 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 with nitrogen gas as a carrier. The activities of the water in the electrolysis cell and of the recombined water were analyzed using a liquid scintillation counter. The apparent D-T separation factor (SF D/T ) and H-T separation factor (SF H/T ) were calculated as quotient the specific activity of the water in the cell divided by that of the recombined water. The electrolysis potential to keep the current 20 A was 2-3 V. The average yields of the recombined water were 95%. At the cell temperature of 20degC, SF D/T (C), SF D/T (SUS), and SF D/T (Ni) were 2.42, 2.17, and 2.05, respectively. At the same temperature, SF H/T (C), SF H/T (SUS), and SF H/T (Ni) were 12.5, 10.8, and 11.8, respectively. The SFs were in agreement with the results in other works. The SFs were changed with the cell temperature. (author)

Electron beam welding of heavy thicknesses with a 200 KW gun

International Nuclear Information System (INIS)

Binard, J.; Ducrot, A.

1986-09-01

In this report, we describe our 200 kW gun, 100 m 3 vacuum chamber E B welding equipment, implemented since 1985 to increase the process development in the heavy mechanics; to score the goal, we study the influence of parameters as: welding positions, chemical analysis of the material and workpiece thickness. Simultaneously, we carry out welding tests of branch pipes or nozzles on tubes and shells. Some results are shown and good mechanical properties are obtained on thicknesses up to 300 mm

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)

Assessment of irradiation effects on beryllium reflector and heavy water tank of JRR-3M

Energy Technology Data Exchange (ETDEWEB)

Murayama, Yoji; Kakehuda, Kazuhiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1998-10-01

The JRR-3M, a swimming pool type research reactor with beryllium and heavy water reflectors, has been operated since 1990. Since the beryllium reflectors are close to fuel and receive high fast neutron fluence in a relatively short time, they may be subject to change their dimensions by swelling due mostly to entrapped helium gaseous. This may bend the reflectors to the outside and narrow gaps between the reflectors and the fuel elements. The gaps have been measured with an ultrasonic thickness gage in an annual inspection. The results in 1996 show that the maximum of expansion in the diametral directions was 0.6 mm against 1.6 mm of a managed value for replacement of the reflector. A heavy water tank of the JRR-3M is made of aluminum alloy A5052. Surveillance tests of the alloy have been conducted to evaluate irradiation effects of the heavy water tank. Five sets of specimens of the alloy have been irradiated in the beryllium reflectors where fast neutron flux is higher than that in the heavy water tank. In 1994, one set of specimens had been unloaded and carried out the post-irradiation tests. The results show that the heavy water tank preserved satisfactory mechanical properties. (author)

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)

Transport of heavy ions in inertial confinement fusion

International Nuclear Information System (INIS)

Parvazian, A.; Shahbandari Gouchani, A.

2007-01-01

In this article we have investigated the interaction of heavy ions (U) with a target (Au). In inertial confinement fusion method Interaction between heavy ion beam and target was simulated, Numerical analysis of the Boltzmann Fokker Planck equation used in order to optimize the material of the target and Energy deposition of ion beam to electrons and ions of target and The thickness of the target were calculated.

Cross section of α-induced reactions on iridium isotopes obtained from thick target yield measurement for the astrophysical γ process

Directory of Open Access Journals (Sweden)

T. Szücs

2018-01-01

Full Text Available The stellar reaction rates of radiative α-capture reactions on heavy isotopes are of crucial importance for the γ process network calculations. These rates are usually derived from statistical model calculations, which need to be validated, but the experimental database is very scarce. This paper presents the results of α-induced reaction cross section measurements on iridium isotopes carried out at first close to the astrophysically relevant energy region. Thick target yields of 191Ir(α,γ195Au, 191Ir(α,n194Au, 193Ir(α,n196mAu, 193Ir(α,n196Au reactions have been measured with the activation technique between Eα=13.4 MeV and 17 MeV. For the first time the thick target yield was determined with X-ray counting. This led to a previously unprecedented sensitivity. From the measured thick target yields, reaction cross sections are derived and compared with statistical model calculations. The recently suggested energy-dependent modification of the α+nucleus optical potential gives a good description of the experimental data.

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

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

Measurement of Li target thickness in the EVEDA Li Test Loop

Energy Technology Data Exchange (ETDEWEB)

Kanemura, Takuji, E-mail: kanemura.takuji@jaea.go.jp [Japan Atomic Energy Agency, 4002 Narita, O-arai, Higashi-Ibaraki-gun, Ibaraki 311-1393 (Japan); Kondo, Hiroo; Furukawa, Tomohiro; Hirakawa, Yasushi [Japan Atomic Energy Agency, 4002 Narita, O-arai, Higashi-Ibaraki-gun, Ibaraki 311-1393 (Japan); Hoashi, Eiji; Yoshihashi, Sachiko; Horiike, Hiroshi [Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Wakai, Eiichi [Japan Atomic Energy Agency, 4002 Narita, O-arai, Higashi-Ibaraki-gun, Ibaraki 311-1393 (Japan)

2015-10-15

Highlights: • The objective is to validate stability of the IFMIF liquid Li target flowing at 15 m/s. • Design requirement of target thickness fluctuation is ±1 mm. • Mean and maximum wave amplitude are 0.26 and 1.46 mm, respectively. • Average thickness can be well predicted with developed analytical model. • Li target was adequately stable and satisfied design requirement. - Abstract: A high-speed (nominal: 15 m/s, range: 10–16 m/s) liquid lithium wall jet is planned to serve as the target for two 40 MeV and 125 mA deuteron beams in the International Fusion Materials Irradiation Facility (IFMIF). The design requirement of target thickness stability is 25 ± 1 mm under a vacuum of 10{sup −3} Pa. This paper presents the results of the target thickness measurement conducted in the EVEDA Li Test Loop under a wide range of conditions including the IFMIF condition (target speed of 10, 15, and 20 m/s; vacuum pressure of 10{sup −3} Pa; and Li temperature of 250 °C). For measurement, we use a laser probe method that we developed in advance; this method generates statistical measurements method using a laser distance meter. The measurement results obtained under the IFMIF nominal condition (15 m/s, 10{sup −3} Pa, 250 °C) at the IFMIF beam center are as follows: average target thickness = 26.08 ± 0.09 mm (2σ), mean wave amplitude = 0.26 ± 0.01 mm (2σ), and maximum wave amplitude = 1.46 ± 0.25 mm (2σ). Of the total wave components, 99.7% are within the design requirement. The analytically predicted target thickness is in excellent agreement with the experimental data, resulting in successful characterization of the Li target thickness.

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)

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)

The importance of subfragment 2 and C-terminus of myosin heavy chain for thick filament assembly in skeletal muscle cells.

Science.gov (United States)

Ojima, Koichi; Oe, Mika; Nakajima, Ikuyo; Shibata, Masahiro; Muroya, Susumu; Chikuni, Koichi; Hattori, Akihito; Nishimura, Takanori

2015-04-01

In skeletal muscle cells, myofibrillar proteins are highly organized into sarcomeres in which thick filaments interdigitate with thin filaments to generate contractile force. The size of thick filaments, which consist mainly of myosin molecules, is strictly controlled. However, little is known about the mechanisms by which myosin molecules assemble into thick filaments. Here, we assessed the ability of each domain of myosin heavy chain (Myh) to form thick filaments. We showed that exogenously expressed subfragment 2 (S2) + light meromyosin (LMM) of Myh was efficiently incorporated into thick filaments in muscle cells, although neither solely expressed S2 nor LMM targeted to thick filaments properly. In nonmuscle COS7 cells, S2+LMM formed more enlarged filaments/speckles than LMM. These results suggest that Myh filament formation is induced by S2 accompanying LMM. We further examined the effects of Myh C-terminus on thick filament assembly. C-terminal deletion mutants were incorporated not into entire thick filaments but rather into restricted regions of thick filaments. Our findings suggest that the elongation of myosin filaments to form thick filaments is regulated by S2 as well as C-terminus of LMM. © 2014 Japanese Society of Animal Science.

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

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)

Kinematics and simulation methods to determine the target thickness

International Nuclear Information System (INIS)

Rosales, P.; Aguilar, E.F.; Martinez Q, E.

2001-01-01

Making use of the kinematics and of the particles energy loss two methods for calculating the thickness of a target are described. Through a computer program and other of simulation in which parameters obtained experimentally are used. Several values for a 12 C target thickness were obtained. It is presented a comparison of the obtained values with each one of the used programs. (Author)

Actinide targets for the synthesis of super-heavy elements

International Nuclear Information System (INIS)

Roberto, J.B.; Alexander, C.W.; Boll, R.A.; Burns, J.D.; Ezold, J.G.; Felker, L.K.; Hogle, S.L.; Rykaczewski, K.P.

2015-01-01

Since 2000, six new super-heavy elements with atomic numbers 113 through 118 have been synthesized in hot fusion reactions of "4"8Ca beams on actinide targets. These target materials, including "2"4"2Pu, "2"4"4Pu, "2"4"3Am, "2"4"5Cm, "2"4"8Cm, "2"4"9Cf, and "2"4"9Bk, are available in very limited quantities and require specialized production and processing facilities resident in only a few research centers worldwide. This report describes the production and chemical processing of heavy actinide materials for super-heavy element research, current availabilities of these materials, and related target fabrication techniques. The impact of actinide materials in super-heavy element discovery is reviewed, and strategies for enhancing the production of rare actinides including "2"4"9Bk, "2"5"1Cf, and "2"5"4Es are described.

Numerical Simulation Study on Steam-Assisted Gravity Drainage Performance in a Heavy Oil Reservoir with a Bottom Water Zone

Directory of Open Access Journals (Sweden)

Jun Ni

2017-12-01

Full Text Available In the Pikes Peak oil field near Lloydminster, Canada, a significant amount of heavy oil reserves is located in reservoirs with a bottom water zone. The properties of the bottom water zone and the operation parameters significantly affect oil production performance via the steam-assisted gravity drainage (SAGD process. Thus, in order to develop this type of heavy oil resource, a full understanding of the effects of these properties is necessary. In this study, the numerical simulation approach was applied to study the effects of properties in the bottom water zone in the SAGD process, such as the initial gas oil ratio, the thickness of the reservoir, and oil saturation of the bottom water zone. In addition, some operation parameters were studied including the injection pressure, the SAGD well pair location, and five different well patterns: (1 two corner wells, (2 triple wells, (3 downhole water sink well, (4 vertical injectors with a horizontal producer, and (5 fishbone well. The numerical simulation results suggest that the properties of the bottom water zone affect production performance extremely. First, both positive and negative effects were observed when solution gas exists in the heavy oil. Second, a logarithmical relationship was investigated between the bottom water production ratio and the thickness of the bottom water zone. Third, a non-linear relation was obtained between the oil recovery factor and oil saturation in the bottom water zone, and a peak oil recovery was achieved at the oil saturation rate of 30% in the bottom water zone. Furthermore, the operation parameters affected the heavy oil production performance. Comparison of the well patterns showed that the two corner wells and the triple wells patterns obtained the highest oil recovery factors of 74.71% and 77.19%, respectively, which are almost twice the oil recovery factors gained in the conventional SAGD process (47.84%. This indicates that the optimized SAGD process

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)

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.)

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.)

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

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.

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

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)

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

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

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

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

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.)

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

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.

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)

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

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

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)

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

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

Measurements of Neutron Spectra Produced from a Thick Iron Target Bombarded with 1.5-GeV Protons

International Nuclear Information System (INIS)

Meigo, Shin-ichiro; Shigyo, Nobuhiro; Iga, Kiminori; Iwamoto, Yosuke; Kitsuki, Hirohiko; Ishibashi, Kenji; Maehata, Keisuke; Arima, Hidehiko; Nakamoto, Tatsushi; Numajiri, Masaharu

2005-01-01

For validation of calculation codes that are employed in the design of accelerator facilities, spectra of neutrons produced from a thick iron target bombarded with 1.5-GeV protons were measured. The calculated results with NMTC/JAM were compared with the present experimental results. It is found that the NMTC/JAM generally shows good agreement with experiment. Furthermore, the calculation gives good agreement with the experiment for the energy region 20 to 80 MeV for iron, whereas the NMTC/JAM gives 50% of the experimental data for the heavy-nuclides such as lead and tungsten

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

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.)

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.

Target design for heavy ion beam fusion

International Nuclear Information System (INIS)

Meyer-ter-Vehn, J.; Metzler, N.

1981-07-01

Target design for Heavy Ion Beam Fusion and related physics are discussed. First, a modified version of the Kidder-Bodner model for pellet gain is presented and is used to define the working point (Esub(beam) = 4.8 MJ, Gain 83) for a reactor size target. Secondly, stopping of heavy ions in hot dense plasma is investigated and numerical results for stopping powers and ranges of 10 GeV Bi-ions in Pb, Li, and PbLi-alloy are given. Finally, results of an explicit implosion calculation, using the 1-D code MINIHY, are discussed in detail. The hydrodynamic efficiency is found to be about 5%. Special attention is given to the shock sequence leading to the ignition configuration. Also the growth of Rayleigh-Taylor instability at the absorber-pusher interface is estimated. (orig.)

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.

Chemical and microstructural analyses for heavy metals removal from water media by ceramic membrane filtration.

Science.gov (United States)

Ali, Asmaa; Ahmed, Abdelkader; Gad, Ali

2017-01-01

This study aims to investigate the ability of low cost ceramic membrane filtration in removing three common heavy metals namely; Pb 2+ , Cu 2+ , and Cd 2+ from water media. The work includes manufacturing ceramic membranes with dimensions of 15 by 15 cm and 2 cm thickness. The membranes were made from low cost materials of local clay mixed with different sawdust percentages of 0.5%, 2.0%, and 5.0%. The used clay was characterized by X-ray diffraction (XRD) and X-ray fluorescence analysis. Aqueous solutions of heavy metals were prepared in the laboratory and filtered through the ceramic membranes. The influence of the main parameters such as pH, initial driving pressure head, and concentration of heavy metals on their removal efficiency by ceramic membranes was investigated. Water samples were collected before and after the filtration process and their heavy metal concentrations were determined by chemical analysis. Moreover, a microstructural analysis using scanning electronic microscope (SEM) was performed on ceramic membranes before and after the filtration process. The chemical analysis results showed high removal efficiency up to 99% for the concerned heavy metals. SEM images approved these results by showing adsorbed metal ions on sides of the internal pores of the ceramic membranes.

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.

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

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)

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

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

Resolving key heavy-ion fusion target issues with relativistic heavy-ion research accelerators

International Nuclear Information System (INIS)

Arnold, R.C.

1988-01-01

Heavy-ion accelerators designed for relativistic nuclear research experiments can also be adapted for target research in heavy-ion driver inertial fusion. Needle-shaped plasmas can be created that are adequate for studying basic properties of matter at high energy density. Although the ion range is very long, the specific deposited power nevertheless increases with kinetic energy, as the focus spot can be made smaller and more ions can be accumulated in larger rings

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.)

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

Measurement of the thickness of a target deposited in a substrate; Medicion del grosor de un blanco depositado en un substrato

Energy Technology Data Exchange (ETDEWEB)

Martinez Q, E.; Aguilera, E.F

1990-12-15

Being based on the Elastic scattering and in the Energy losses that suffer a projectile to the interacting with the matter, a method that allows to determine the thickness of a target deposited in a more heavy substrate is presented. The obtained results are consistent with that waited and the derived errors of the method are small. The used technique allows to reduce in considerable form the systematic errors coming from the calibration of the equipment. It is considered that this method is applicable in an interval of thickness quite wide and for many materials since it is only necessary to choose the projectile type and the energy of the same one appropriately. (Author)

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

Slow, target associated particles produced in ultrarelativistic heavy-ion interactions

Energy Technology Data Exchange (ETDEWEB)

Adamovich, M I; Aggarwal, M M; Alexandrov, Y A; Andreeva, N P; Anson, Z V; Arora, R; Avetyan, F A; Badyal, S K; Basova, E; Bhalla, K B; Bhasin, A; Bhatia, V S; Bogdanov, V G; Bubnov, V I; Burnett, T H; Cai, X; Chasnikov, I Y; Chernova, L P; Chernyavsky, M M; Dressel, B; Eligbaeva, G Z; Eremenko, L E; Friedlander, E M; Gaitinov, A S; Ganssauge, E R; Garpman, S; Gerassimov, S G; Grote, J; Gulamov, K G; Gupta, S K; Gupta, V; Heckman, H H; Huang, H; Jakobsson, B; Judek, B; Kachroo, S; Kadyrov, F G; Kalyachkina, G S; Kanygina, E K; Karabova, M; Kaul, G L; Kaur, M; Kharlamov, S P; Koss, Y; Krasnov,; Kumar,; Lal, P; Larionova,; Lepetan,; Lindstrom,; Liu,; Lokanathan, S; Lord, J; Lukicheva, N S; Luo, S B; Mangotra, L K; Marutyan,; Maslennikova, N V; Mittra, I S; Mookerjee, S; Mueller, C; Nasrulaeva, H; Nasyrov, S H; Navotny, V S; Orlova, G I; Otterlund, I; Palsania, H S; Peresadko, N G; Petrov, N V; Plyushchev, V A; Qian, W Y; Raniwala,; EMU01 Collaboration

1991-06-20

The slow, target associated particles produced in ultrarelativistic heavy-ion interactions are a quantitative probe of the cascading processes in the spectator parts of the target nucleus. These processes are directly influenced by the proper timescale for the formation of hadronic matter. In this letter we show experimental data on singly and multiply charged particles, with velocities smaller than 0.7c, produced in ultrarelativistic heavy-ion interactions in nuclear emulsion. (orig.).

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

Radiographic detection of 100 A thickness variations in 1-μm-thick coatings applied to submillimeter-diameter laser fusion targets

International Nuclear Information System (INIS)

Stupin, D.M.

1986-01-01

We have developed x-ray radiography to measure thickness variations of coatings on laser fusion targets. Our technique is based on measuring the variation in x-ray transmission through the targets. The simplest targets are hollow glass microshells or microballoons 100 to 500 μm in diameter, that have several layers of metals or plastics, 1 to 100 μm thick. Our goal is to examine these opaque coatings for thickness variations as small as 1% or 0.1%, depending on the type of defect. Using contact radiography we have obtained the desired sensitivity for concentric and elliptical defects of 1%. This percentage corresponds to thickness variations as small as 100 A in a 1-μm-thick coating. For warts and dimples, the desired sensitivity is a function of the area of the defect, and we are developing a system to detect 0.1% thickness variations that cover an area 10 μm by 10 μm. We must use computer analysis of contact radiographs to measure 1% thickness variations in either concentricity or ellipticity. Because this analysis takes so long on our minicomputer, we preselect the radiographs by looking for defects at the 10% level on a video image analysis system

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)

Relationship between Pipeline Wall Thickness (Gr. X60) and Water Depth towards Avoiding Failure during Installation

Science.gov (United States)

Razak, K. Abdul; Othman, M. I. H.; Mat Yusuf, S.; Fuad, M. F. I. Ahmad; yahaya, Effah

2018-05-01

Oil and gas today being developed at different water depth characterized as shallow, deep and ultra-deep waters. Among the major components involved during the offshore installation is pipelines. Pipelines are a transportation method of material through a pipe. In oil and gas industry, pipeline come from a bunch of line pipe that welded together to become a long pipeline and can be divided into two which is gas pipeline and oil pipeline. In order to perform pipeline installation, we need pipe laying barge or pipe laying vessel. However, pipe laying vessel can be divided into two types: S-lay vessel and J-lay vessel. The function of pipe lay vessel is not only to perform pipeline installation. It also performed installation of umbilical or electrical cables. In the simple words, pipe lay vessel is performing the installation of subsea in all the connecting infrastructures. Besides that, the installation processes of pipelines require special focus to make the installation succeed. For instance, the heavy pipelines may exceed the lay vessel’s tension capacities in certain kind of water depth. Pipeline have their own characteristic and we can group it or differentiate it by certain parameters such as grade of material, type of material, size of diameter, size of wall thickness and the strength. For instances, wall thickness parameter studies indicate that if use the higher steel grade of the pipelines will have a significant contribution in pipeline wall thickness reduction. When running the process of pipe lay, water depth is the most critical thing that we need to monitor and concern about because of course we cannot control the water depth but we can control the characteristic of the pipe like apply line pipe that have wall thickness suitable with current water depth in order to avoid failure during the installation. This research will analyse whether the pipeline parameter meet the requirements limit and minimum yield stress. It will overlook to simulate pipe

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)

Spallation neutron production on thick target at saturne

International Nuclear Information System (INIS)

David, J.C.; David, J.C.; Varignon, C.; Borne, F.; Boudard, A.; Brochard, F.; Crespin, S.; Duchazeaubeneix, J.C.; Durand, D.; Durand, J.M.; Frehaut, J.; Hannappe, F.; Lebrun, C.; Lecolley, J.F.; Ledoux, X.; Lefebvres, F.; Legrain, R.; Leray, S.; Louvel, M.; Martinez, E.; Menard, S.; Milleret, G.; Patin, Y.; Petitbon, E.; Plouin, F.; Schapira, J.P.; Stugge, L.; Terrien, Y.; Thun, J.; Volant, C.; Whittal, D.M.

2003-01-01

In view of the new spallation neutron source projects, we discuss the characteristics of the neutron spectra on thick targets measured at SATURNE. Some comparisons to spallation models, and especially INCL4/ABLA implemented in the LAHET code, are done. (orig.)

Basic atomic interactions of accelerated heavy ions in matter atomic interactions of heavy ions

CERN Document Server

Tolstikhina, Inga; Winckler, Nicolas; Shevelko, Viacheslav

2018-01-01

This book provides an overview of the recent experimental and theoretical results on interactions of heavy ions with gaseous, solid and plasma targets from the perspective of atomic physics. The topics discussed comprise stopping power, multiple-electron loss and capture processes, equilibrium and non-equilibrium charge-state fractions in penetration of fast ion beams through matter including relativistic domain. It also addresses mean charge-states and equilibrium target thickness in ion-beam penetrations, isotope effects in low-energy electron capture, lifetimes of heavy ion beams, semi-empirical formulae for effective cross sections. The book is intended for researchers and graduate students working in atomic, plasma and accelerator physics.

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

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

Turning the volume down on heavy metals using tuned diatomite. A review of diatomite and modified diatomite for the extraction of heavy metals from water.

Science.gov (United States)

Danil de Namor, Angela F; El Gamouz, Abdelaziz; Frangie, Sofia; Martinez, Vanina; Valiente, Liliana; Webb, Oliver A

2012-11-30

Contamination of water by heavy metals is a global problem, to which an inexpensive and simple solution is required. Within this context the unique properties of diatomite and its abundance in many regions of the world have led to the current widespread interest in this material for water purification purposes. Defined sections on articles published on the use of raw and modified diatomite for the removal of heavy metal pollutants from water are critically reviewed. The capability of the materials as extracting agents for individual species and mixtures of heavy metals are considered in terms of the kinetics, the thermodynamics and the recyclability for both, the pollutant and the extracting material. The concept of 'selectivity' for the enrichment of naturally occurring materials such as diatomite through the introduction of suitable functionalities in their structure to target a given pollutant is emphasised. Suggestions for further research in this area are given. Copyright © 2012 Elsevier B.V. All rights reserved.

Measurement of residual radioactivity in cooper exposed to high energy heavy ion beam

Energy Technology Data Exchange (ETDEWEB)

Kim, Eunjoo; Nakamura, Takashi [Tohoku Univ., Sendai (Japan). Cyclotron and Radioisotope Center; Uwamino, Yoshitomo; Ito, Sachiko; Fukumura, Akifumi

1999-03-01

The residual radioactivities produced by high energy heavy ions have been measured using the heavy ion beams of the Heavy Ion Medical Accelerator (HIMAC) at National Institute of Radiological Sciences. The spatial distribution of residual radioactivities in 3.5 cm, 5.5 cm and 10 cm thick copper targets of 10 cm x 10 cm size bombarded by 290 MeV/u, 400 MeV/u-{sup 12}C ion beams and 400 MeV/u-{sup 20}Ne ion beam, respectively, were obtained by measuring the gamma-ray activities of 0.5 mm thick copper foil inserted in the target with a high purity Ge detector after about 1 hour to 6 hours irradiation. (author)

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

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)

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.

Calculated /alpha/-induced thick target neutron yields and spectra, with comparison to measured data

International Nuclear Information System (INIS)

Wilson, W.B.; Bozoian, M.; Perry, R.T.

1988-01-01

One component of the neutron source associated with the decay of actinide nuclides in many environments is due to the interaction of decay /alpha/ particles in (/alpha/,n) reactions on low Z nuclides. Measurements of (/alpha/,n) thick target neutron yields and associated neutron spectra have been made for only a few combinations of /alpha/ energy and target nuclide or mixtures of actinide and target nuclides. Calculations of thick target neutron yields and spectra with the SOURCES code require /alpha/-energy-dependent cross sections for (/alpha/,n) reactions, as well as branching fractions leading to the energetically possible levels of the product nuclides. A library of these data has been accumulated for target nuclides of Z /le/ 15 using that available from measurements and from recent GNASH code calculations. SOURCES, assuming neutrons to be emitted isotopically in the center-of-mass system, uses libraries of /alpha/ stopping cross sections, (/alpha/,n) reaction cross reactions, product nuclide level branching fractions, and actinide decay /alpha/ spectra to calculate thick target (/alpha/,n) yields and neutron spectra for homogeneous combinations of nuclides. The code also calculates the thick target yield and angle intergrated neutron spectrum produced by /alpha/-particle beams on targets of homogeneous mixtures of nuclides. Illustrative calculated results are given and comparisons are made with measured thick target yields and spectra. 50 refs., 1 fig., 2 tabs

Turning the volume down on heavy metals using tuned diatomite. A review of diatomite and modified diatomite for the extraction of heavy metals from water

International Nuclear Information System (INIS)

Danil de Namor, Angela F.; El Gamouz, Abdelaziz; Frangie, Sofia; Martinez, Vanina; Valiente, Liliana; Webb, Oliver A.

2012-01-01

Highlights: ► Critical assessment of published work on raw and modified diatomites. ► Counter-ion effect on the extraction of heavy metal speciation by diatomite. ► Selection of the counter-ion by the use of existing thermodynamic data. ► Enrichment of diatomites by attaching heavy metal selective functionalities. ► Supramolecular chemistry for conferring selectivity to diatomites. - Abstract: Contamination of water by heavy metals is a global problem, to which an inexpensive and simple solution is required. Within this context the unique properties of diatomite and its abundance in many regions of the world have led to the current widespread interest in this material for water purification purposes. Defined sections on articles published on the use of raw and modified diatomite for the removal of heavy metal pollutants from water are critically reviewed. The capability of the materials as extracting agents for individual species and mixtures of heavy metals are considered in terms of the kinetics, the thermodynamics and the recyclability for both, the pollutant and the extracting material. The concept of ‘selectivity’ for the enrichment of naturally occurring materials such as diatomite through the introduction of suitable functionalities in their structure to target a given pollutant is emphasised. Suggestions for further research in this area are given.

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)

Neutron yield from thick lead target by the action of high-energy electrons

International Nuclear Information System (INIS)

Noga, V.I.; Ranyuk, Yu.N.; Telegin, Yu.N.; Sorokin, P.V.

1978-01-01

The results are presented of studying the complete neutron yield from a lead target bombarded by high-energy electrons. Neutrons were recorded by the method of radio-active indicators. The dependence of the neutron yield on the target thickness varying from 0.2 to 8 cm was obtained at the energies of electrons of 230 and 1200 MeV. The neutron yield for the given energies with the target of 6 cm in thickness is in the range of saturation and is 0.1 +-0.03 and 0.65+-0.22 (neutr./MeV.el.), respectively. The neutron angular distributions were measured for different thicknesses of targets at the 201, 230 and 1200 MeV electrons. Within the error limits the angular distributions are isotropic. The dependence of neutron yield on the electron energy was examined for a 3 cm thick target. In the energy range of 100-1200 MeV these values are related by a linear dependence with the proportionality coefficient C=3x10 -4 (neutr./MeV.el.)

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)

The effect of target thickness on x-ray production by FXR [Flash X-Ray Machine

International Nuclear Information System (INIS)

Back, N.L.

1986-01-01

The electron-photon transport code SANDYL has been used to calculate the x-ray flux for a simplified Flash X-Ray Machine (FXR) bullnose geometry. Four different thicknesses (24.5, 36.75, 49, and 61.25 mils) were used for the tantalum bremsstrahlung target in order to study the effect of target thickness on the FXR output. The calculations were performed for a parallel 17 MeV electron beam, and the resulting angular distributions were then used to compute the forward flux for the more realistic case of a converging beam. Over the range of thicknesses studied, the x-ray energy content per steradian on axis was essentially independent of target thickness. The main reason for this is that, while the total x-ray flux coming out of the target increases with increasing target thickness, the angular width of that flux also increases. The implications for target wheel design are discussed. 3 refs., 7 figs

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

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

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

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)

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)

Thick target spallation product yields from 800 MeV protons on tungsten

International Nuclear Information System (INIS)

Ullmann, J.L.; Staples, P.; Butler, G.

1994-01-01

A number of newly-conceived accelerator based technologies will employ medium-energy particles stopping in thick targets to produce large numbers of neutrons. It is important to quantify the residual radionuclides in the target because one must understand what nuclei and decay gammas are produced in order to design adequate shielding, to estimate ultimate waste disposal problems, and to predict possible effects of accidental dispersion during operation. Because stopping-length targets are considered, radionuclide production must be known as a function of energy. Moreover, secondary particle production, mostly neutrons, implies a need to be able to calculate particle transport. To test the overall ability to calculate radionuclide yields, a thick-target measurement was carried out and the results compared to detailed calculations. Although numerous measurements of thin-target spallation yields have been made, there have been only a few measurements on thick systems. The most complete study showed results for Pb and U systems. In this contribution, the authors report on measurements made for a stopping-length W target. Special efforts were made to measure short-lived isotopes, and reliable data on isotopes with two or three minute half-lives were obtained

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

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)

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.)

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)

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)

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)

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

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)

Turning the volume down on heavy metals using tuned diatomite. A review of diatomite and modified diatomite for the extraction of heavy metals from water

Energy Technology Data Exchange (ETDEWEB)

Danil de Namor, Angela F., E-mail: A.Danil-De-Namor@surrey.ac.uk [Instituto Nacional de Tecnologia Industrial, Parque Tecnologico Industrial Miguelete, Buenos Aires (Argentina); Department of Chemistry, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); El Gamouz, Abdelaziz [Department of Chemistry, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); Frangie, Sofia; Martinez, Vanina; Valiente, Liliana [Instituto Nacional de Tecnologia Industrial, Parque Tecnologico Industrial Miguelete, Buenos Aires (Argentina); Webb, Oliver A. [Department of Chemistry, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

2012-11-30

Highlights: Black-Right-Pointing-Pointer Critical assessment of published work on raw and modified diatomites. Black-Right-Pointing-Pointer Counter-ion effect on the extraction of heavy metal speciation by diatomite. Black-Right-Pointing-Pointer Selection of the counter-ion by the use of existing thermodynamic data. Black-Right-Pointing-Pointer Enrichment of diatomites by attaching heavy metal selective functionalities. Black-Right-Pointing-Pointer Supramolecular chemistry for conferring selectivity to diatomites. - Abstract: Contamination of water by heavy metals is a global problem, to which an inexpensive and simple solution is required. Within this context the unique properties of diatomite and its abundance in many regions of the world have led to the current widespread interest in this material for water purification purposes. Defined sections on articles published on the use of raw and modified diatomite for the removal of heavy metal pollutants from water are critically reviewed. The capability of the materials as extracting agents for individual species and mixtures of heavy metals are considered in terms of the kinetics, the thermodynamics and the recyclability for both, the pollutant and the extracting material. The concept of 'selectivity' for the enrichment of naturally occurring materials such as diatomite through the introduction of suitable functionalities in their structure to target a given pollutant is emphasised. Suggestions for further research in this area are given.

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)

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

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.))

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

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.

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.

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)

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

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)

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

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)

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

Measured and calculated neutron yields for 100 MeV protons on thick targets of Pb and Li

International Nuclear Information System (INIS)

Jones, R.T.; Lone, M.A.; Okazaki, A.

1983-01-01

The neutron yield per proton from thick targets of lead and lithium irradiated with 100 MeV protons has been measured and calculated. The water bath method was used to measure the neutron production, and a Faraday cup for the beam current determination. Measured yields are 0.343 +- 0.021 for lead and 0.123 +- 0.007 for lithium. Corresponding yields calculated with the nucleon-meson transport code NMTC are 0.363 +- 0.002 and 0.160 +- 0.001. Measured and calculated thermal neutron distributions in the water bath are also compared

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 ...

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)

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.

Charged state distributions of swift heavy ions behind various solid targets (36 ≤ Zp ≤ 92, 18 MeV/u ≤ E ≤ 44 MeV/u)

International Nuclear Information System (INIS)

Leon, A.; Melki, S.; Lisfi, D.; Grandin, J.P.; Jardin, P.; Suraud, M.G.; Cassimi, A.

1998-01-01

Noting the lack of and the increasing need for information concerning heavy ion stripping in the intermediate velocity regime, the authors have studied a large number of ion-target systems experimentally. They present experimental charge state distributions obtained at the GANIL accelerator for several projectiles (36 ≤ Z p ≤ 92) with energies ranging from 18 MeV/u to 44 MeV/u, emerging from various target foils (4 ≤ Z t ≤ 79) of natural isotopic composition. The target thicknesses (from 1 microg/cm 2 up to several mg/cm 2 ) are chosen to cover the pre- and post-charge-state equilibrium regimes. Charge state fractions, mean charge state, charge distribution width, and emerging ion energy are tabulated for each of the 107 projectile-target element-target thickness combinations. They also present an improvement of the semi-empirical formulae proposed by Baron et al. to predict the mean charge states and the distribution widths at equilibrium. These formulae are compared with the available experimental data

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)

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.

Characterization of a material by probability of linear scattering using effect of target thickness

International Nuclear Information System (INIS)

Nghiep, T.D.; Khai, N.T.; Cong, N.T.; Minh, D.T.N.

2013-01-01

We report on an experimental test with 662 keV gamma photons scattered from a set of samples from 6 C, 13 Al, 26 Fe, 29 Cu, 47 Ag, 82 Pb and stainless steel for determination of probability of linear scattering, which can be used for characterization of a material. The results show that for the given target and scattering angle, the effect of target thickness in gamma photons scattering relates to single and multiple scattering and that the scattered events exponentially increase with an increase in target thickness and saturation at some values of thickness. The experimental results correlate with the typical function of energy transfer model. (author)

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)

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)

Monte Carlo simulation for neutron yield produced by bombarding thick targets with high energy heavy ions

Energy Technology Data Exchange (ETDEWEB)

Oranj, Leila Mokhtari; Oh, Joo Hee; Yoon, Moo Hyun; Lee, Hee Seock [POSTECH, Pohang (Korea, Republic of)

2013-04-15

One of radiation shielding issues at heavy-ion accelerator facilities is to estimate neutron production by primary heavy ions. A few Monte Carlo transport codes such as FLUKA and PHITS can work with primary heavy ions. Recently IBS/RISP((Rare Isotope Science Project) started to design a high-energy, high-power rare isotope accelerator complex for nuclear physics, medical and material science and applications. There is a lack of experimental and simulated data about the interaction of major beam, {sup 238}U with materials. For the shielding design of the end of first accelerating section section, we calculate a differential neutron yield using the FLUKA code for the interaction of 18.5 MeV/u uranium ion beam with thin carbon stripper of 1.3 μm). The benchmarking studies were also done to prove the yield calculation for 400 MeV/n {sup 131}Xe and other heavy ions. In this study, the benchmarking for Xe-C, Xe-Cu, Xe-Al, Xe-Pb and U-C, other interactions were performed using the FLUKA code. All of results show that the FLUKA can evaluate the heavy ion induced reaction with good uncertainty. For the evaluation of neutron source term, the calculated neutron yields are shown in Fig. 2. The energy of Uranium ion beam is only 18.5 MeV/u, but the energy of produced secondary neutrons was extended over 100 MeV. So the neutron shielding and the damage by those neutrons is expected to be serious. Because of thin stripper, the neutron intensity at forward direction was high. But the the intensity of produced secondary photons was relatively low and mostly the angular property was isotropic. For the detail shielding design of stripper section of RISP rare istope accelerator, the benchmarking study and preliminary evaluation of neutron source term from uranium beam have been carried out using the FLUKA code. This study is also compared with the evaluation results using the PHITS code performed coincidently. Both studies shows that two monte carlo codes can give a good results for

Development of a higher power cooling system for lithium targets.

Science.gov (United States)

Phoenix, B; Green, S; Scott, M C; Bennett, J R J; Edgecock, T R

2015-12-01

The accelerator based Boron Neutron Capture Therapy beam at the University of Birmingham is based around a solid thick lithium target cooled by heavy water. Significant upgrades to Birmingham's Dynamitron accelerator are planned prior to commencing a clinical trial. These upgrades will result in an increase in maximum achievable beam current to at least 3 mA. Various upgrades to the target cooling system to cope with this increased power have been investigated. Tests of a phase change coolant known as "binary ice" have been carried out using an induction heater to provide a comparable power input to the Dynamitron beam. The experimental data shows no improvement over chilled water in the submerged jet system, with both systems exhibiting the same heat input to target temperature relation for a given flow rate. The relationship between the cooling circuit pumping rate and the target temperature in the submerged jet system has also been tested. Copyright © 2015 Elsevier Ltd. All rights reserved.

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)

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.

Neutron Production from In-situ Heavy Ice Coated Targets at Vulcan

Science.gov (United States)

Morrison, John; Krygier, A. G.; Kar, S.; Ahmed, H.; Alejo, A.; Clarke, R.; Fuchs, J.; Green, A.; Jung, D.; Kleinschmidt, A.; Najmudin, Z.; Nakamura, H.; Norreys, P.; Notley, M.; Oliver, M.; Roth, M.; Vassura, L.; Zepf, M.; Borghesi, M.; Freeman, R. R.

2015-05-01

Laser based neutron production experiments have been performed utilizing ultra-high intensity laser accelerated ions impinging upon a secondary target. The neutron yield from such experiments may be improved if the accelerated ions were primarily deuterons taking advantage of the d-d cross section. Recent experiments have demonstrated that selective deuteron acceleration from in-situ heavy ice coating of targets can produce ion spectra where deuterons comprise > 99 % of the measured ions. Results will be presented from integrated neutron production experiments from heavy ice targets coated in-situ recently performed on the Vulcan laser at Rutherford Appleton Laboratory. We are grateful for the Staff at RAL and acknowledge funding from the US DoE. AFOSR, European Social Fund, and the Czech Republic.

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)

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.

Assembler absolute forward thick-target bremsstrahlung spectra program

International Nuclear Information System (INIS)

Niculescu, V.I.R.; Baciu, G.; Ionescu-Bujor, M.

1981-12-01

The program is intended to compute the absolute forward thick-target bremsstrahlung spectrum for electrons in the energy range 1-24 MeV. The program takes into account the following phenomena: multiple scattering, energy loss and the attenuation of the emitted gamma rays. The computer program is written in Assembler having a higher degree of generality and is more performant than the FORTRAN version. (authors)

Heavy ion fusion targets; issues for fast ignition

International Nuclear Information System (INIS)

Bangerter, Roger O.

2014-01-01

During the last 36 years researchers have suggested and evaluated a large number of target designs for heavy ion inertial fusion. The different target designs can be classified according to their mode of ignition, their method of implosion, and their size. Ignition modes include hot-spot ignition and fast ignition. Methods of implosion include direct drive and indirect drive. Historically there has been significant work on indirectly driven targets with hot-spot ignition. Recently there has been increasing interest in directly driven targets with ion driven fast ignition. In principle, fast ignition might lead to improved target performance. On the other hand, fast ignition imposes stringent requirements on accelerators and beam physics. Furthermore, fast ignition magnifies the importance of a number of traditional target physics issues associated with ion beam energy deposition and fuel preheat. This paper will discuss the advantages and disadvantages of the various classes of targets. It will also discuss some issues that must be resolved to assess the feasibility of ion fast ignition

Recent heavy flavor physics results from fixed target experiments

International Nuclear Information System (INIS)

Spiegel, L.

1991-11-01

Recent results from fixed target experiments in the field of heavy quark flavors, as published or otherwise disseminated in the last year, are reviewed. Emphasis is placed on distilling the main conclusions from these results. 35 refs., 5 figs., 4 tabs

Recent heavy flavor physics results from fixed target experiments

Energy Technology Data Exchange (ETDEWEB)

Spiegel, L.

1991-11-01

Recent results from fixed target experiments in the field of heavy quark flavors, as published or otherwise disseminated in the last year, are reviewed. Emphasis is placed on distilling the main conclusions from these results. 35 refs., 5 figs., 4 tabs.

Impact of Different CT Slice Thickness on Clinical Target Volume for 3D Conformal Radiation Therapy

International Nuclear Information System (INIS)

Prabhakar, Ramachandran; Ganesh, Tharmar; Rath, Goura K.; Julka, Pramod K.; Sridhar, Pappiah S.; Joshi, Rakesh C.; Thulkar, Sanjay

2009-01-01

The purpose of this study was to present the variation of clinical target volume (CTV) with different computed tomography (CT) slice thicknesses and the impact of CT slice thickness on 3-dimensional (3D) conformal radiotherapy treatment planning. Fifty patients with brain tumors were selected and CT scans with 2.5-, 5-, and 10-mm slice thicknesses were performed with non-ionic contrast enhancement. The patients were selected with tumor volume ranging from 2.54 cc to 222 cc. Three-dimensional treatment planning was performed for all three CT datasets. The target coverage and the isocenter shift between the treatment plans for different slice thickness were correlated with the tumor volume. An important observation from our study revealed that for volume 25 cc, the target underdosage was less than 6.7% for 5-mm slice thickness and 8% for 10-mm slice thickness. For 3D conformal radiotherapy treatment planning (3DCRT), a CT slice thickness of 2.5 mm is optimum for tumor volume 25 cc

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

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...

Ionization of heavy targets by impact of relativistic projectiles

International Nuclear Information System (INIS)

Deco, G.R.; Fainstein, P.D.; Comision Nacional de Energia Atomica, San Carlos de Bariloche; Rivarola, R.D.

1988-01-01

Electron ejection from atomic targets by impact of bare heavy projectiles at relativistic collision energies is studied theoretically. First-order Born calculations are presented by using initial Darwin and final Sommerfeld-Maue wavefunctions. Comparisons with other calculations and experimental data are given. (orig.)

Heavy-Quark Production in the Target Fragmentation Region

CERN Document Server

Graudenz, Dirk

1997-01-01

Fixed-target experiments permit the study of hadron production in the target fragmentation region. It is expected that the tagging of specific particles in the target fragments can be employed to introduce a bias in the hard scattering process towards a specific flavour content. The case of hadrons containing a heavy quark is particularly attractive because of the clear experimental signatures and the applicability of perturbative QCD. The standard approach to one-particle inclusive processes based on fragmentation functions is valid in the current fragmentation region and for large transverse momenta $p_T$ in the target fragmentation region, but it fails for particle production at small $p_T$ in the target fragmentation region. A collinear singularity, which cannot be absorbed in the standard way into the phenomenological distribution functions, prohibits the application of this procedure. This situation is remedied by the introduction of a new set of distribution functions, the target fragmentation function...

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.

Enhanced electron emission from coated metal targets: Effect of surface thickness on performance

Directory of Open Access Journals (Sweden)

Saibabu Madas

2018-03-01

Full Text Available In this work, we establish an analytical formalism to address the temperature dependent electron emission from a metallic target with thin coating, operating at a finite temperature. Taking into account three dimensional parabolic energy dispersion for the target (base material and suitable thickness dependent energy dispersion for the coating layer, Fermi Dirac statistics of electron energy distribution and Fowler’s mechanism of the electron emission, we discuss the dependence of the emission flux on the physical properties such as the Fermi level, work function, thickness of the coating material, and operating temperature. Our systematic estimation of how the thickness of coating affects the emission current demonstrates superior emission characteristics for thin coating layer at high temperature (above 1000 K, whereas in low temperature regime, a better response is expected from thicker coating layer. This underlying fundamental behavior appears to be essentially identical for all configurations when work function of the coating layer is lower than that of the bulk target work function. The analysis and predictions could be useful in designing new coated materials with suitable thickness for applications in the field of thin film devices and field emitters.

Enhanced electron emission from coated metal targets: Effect of surface thickness on performance

Science.gov (United States)

Madas, Saibabu; Mishra, S. K.; Upadhyay Kahaly, Mousumi

2018-03-01

In this work, we establish an analytical formalism to address the temperature dependent electron emission from a metallic target with thin coating, operating at a finite temperature. Taking into account three dimensional parabolic energy dispersion for the target (base) material and suitable thickness dependent energy dispersion for the coating layer, Fermi Dirac statistics of electron energy distribution and Fowler's mechanism of the electron emission, we discuss the dependence of the emission flux on the physical properties such as the Fermi level, work function, thickness of the coating material, and operating temperature. Our systematic estimation of how the thickness of coating affects the emission current demonstrates superior emission characteristics for thin coating layer at high temperature (above 1000 K), whereas in low temperature regime, a better response is expected from thicker coating layer. This underlying fundamental behavior appears to be essentially identical for all configurations when work function of the coating layer is lower than that of the bulk target work function. The analysis and predictions could be useful in designing new coated materials with suitable thickness for applications in the field of thin film devices and field emitters.

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

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

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

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

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.

"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.

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.)

Influence of target thickness on the release of radioactive atoms

Energy Technology Data Exchange (ETDEWEB)

Guillot, Julien, E-mail: guillotjulien@ipno.in2p3.fr [Institut de Physique Nucléaire CNRS/IN2P3 UMR 8608 – Université Paris Sud – Université Paris Saclay, F-91406 Orsay Cedex (France); Roussière, Brigitte [Institut de Physique Nucléaire CNRS/IN2P3 UMR 8608 – Université Paris Sud – Université Paris Saclay, F-91406 Orsay Cedex (France); Tusseau-Nenez, Sandrine [Physique de la Matière Condensée Ecole Polytechnique/CNRS UMR 7643 – Université Paris Saclay, F-91128 Palaiseau Cedex (France); Barré-Boscher, Nicole; Borg, Elie; Martin, Julien [Institut de Physique Nucléaire CNRS/IN2P3 UMR 8608 – Université Paris Sud – Université Paris Saclay, F-91406 Orsay Cedex (France)

2017-03-01

Nowadays, intense exotic beams are needed in order to study nuclei with very short half-life. To increase the release efficiency of the fission products, all the target characteristics involved must be improved (e.g. chemical composition, dimensions, physicochemical properties such as grain size, porosity, density…). In this article, we study the impact of the target thickness. Released fractions measured from graphite and uranium carbide pellets are presented as well as Monte-Carlo simulations of the Brownian motion.

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

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

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, ...

Ion acceleration by radiation pressure in thin and thick targets

Energy Technology Data Exchange (ETDEWEB)

Macchi, Andrea, E-mail: macchi@df.unipi.i [CNR/INFM/polyLAB, Pisa (Italy); Dipartimento di Fisica ' Enrico Fermi' , Largo Bruno Pontecorvo 3, I-56127 Pisa (Italy); Benedetti, Carlo, E-mail: Carlo.Benedetti@bo.infn.i [Dipartimento di Fisica, Universita di Bologna and INFN, Via Irnerio 46, I-40126 Bologna (Italy)

2010-08-01

Radiation Pressure Acceleration (RPA) by circularly polarized laser pulses is emerging as a promising way to obtain efficient acceleration of ions. We briefly review theoretical work on the topic, aiming at characterizing suitable experimental scenarios. We discuss the two reference cases of RPA, namely the thick target ('Hole Boring') and the (ultra)thin target ('Light Sail') regimes. The different scaling laws of the two regimes, the related experimental challenges and their suitability for foreseen applications are discussed.

Investigations of effect of target thickness and detector collimation on 662 keV multiply backscattered gamma photons

International Nuclear Information System (INIS)

Sabharwal, Arvind D.; Sandhu, B.S.; Singh, Bhajan

2009-01-01

The present studies aimed to investigate the effects of detector collimation and target thickness on multiply backscattered gamma photons. The numbers of multiply backscattered events, having energy the same as in singly scattered distribution, are found to be increasing with target thickness, and saturate for a particular thickness known as saturation thickness. The saturation thickness is not altered by the variation in the collimator opening. The number and energy albedos, characterizing the reflection probability of a material, are also evaluated. Monte Carlo calculations support the present experimental work.

Design, construction and performance evaluation of the target tissue thickness measurement system in intraoperative radiotherapy for breast cancer

Energy Technology Data Exchange (ETDEWEB)

Yazdani, Mohammad Reza, E-mail: myazdani@aut.ac.ir [Faculty of Energy Engineering and Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Setayeshi, Saeed, E-mail: setayesh@aut.ac.ir [Faculty of Energy Engineering and Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Arabalibeik, Hossein, E-mail: arabalibeik@tums.ac.ir [Research Center for Biomedical Technology and Robotics (RCBTR), Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Akbari, Mohammad Esmaeil [Cancer Research Center, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of)

2017-05-21

Intraoperative electron radiation therapy (IOERT), which uses electron beams for irradiating the target directly during the surgery, has the advantage of delivering a homogeneous dose to a controlled layer of tissue. Since the dose falls off quickly below the target thickness, the underlying normal tissues are spared. In selecting the appropriate electron energy, the accuracy of the target tissue thickness measurement is critical. In contrast to other procedures applied in IOERT, the routine measurement method is considered to be completely traditional and approximate. In this work, a novel mechanism is proposed for measuring the target tissue thickness with an acceptable level of accuracy. An electronic system has been designed and manufactured with the capability of measuring the tissue thickness based on the recorded electron density under the target. The results indicated the possibility of thickness measurement with a maximum error of 2 mm for 91.35% of data. Aside from system limitation in estimating the thickness of 5 mm phantom, for 88.94% of data, maximum error is 1 mm.

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

investigating water absorption and thickness swelling tendencies

African Journals Online (AJOL)

HOD

In addition, G30E (30% reinforced glass fibre in the epoxy composite) was more resilient to moisture ... determine its suitability as per its water absorption and thickness ... lower thermal conductivity and low density as outlined in the Tables.

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.

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

Ultrasonic evaluation of end cap weld joints of fuel elements of pressurized heavy water reactors using signal analysis methods

International Nuclear Information System (INIS)

Raj, B.; Thavasimuthu, M.; Subramanian, C.V.; Kalyanasundaram, P.; Rajagopalan, C.

1992-01-01

This paper describes the application of ultrasonic digital signal analysis for the detection of fine defects of the order of 10% or lower of wall thickness (WT) of 370 microns in the resistance welded end cap-cladding tube joints of fuel elements used in Pressurised Heavy Water Reactors (PHWR s). The results obtained for the detection of such defects, have confirmed the sensitivity and reliability of this approach, and were further validated by destructive metallography. (author)

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

Electron loss from heavy heliumlike projectiles in ultrarelativistic collisions with many-electron atomic targets

International Nuclear Information System (INIS)

Mueller, C.; Gruen, N.; Voitkiv, A.B.

2002-01-01

We study single- and double-electron loss from heavy heliumlike projectiles in ultrarelativistic collisions with neutral many-electron target atoms. The simultaneous interaction of the target with two projectile electrons is found to be the dominant process in the double-electron loss provided the atomic number of the projectile, Z p , that of the target, Z t , and the collision velocity, v, satisfy the condition Z p Z t /v>0.4. It is shown that for a wide range of projectile and target atomic numbers the asymptotic double-to-single loss ratio strongly depends on the target atomic number but is nearly independent of the nuclear charge of the projectile. It is also demonstrated that many-photon exchange between the target and each of the projectile electrons considerably influences the double loss in collisions with very heavy targets

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).

Thick-target method in the measurement of inner-shell ionization cross-sections by low-energy electron impact

International Nuclear Information System (INIS)

An, Z.; Wu, Y.; Liu, M.T.; Duan, Y.M.; Tang, C.H.

2006-01-01

In this paper, we have studied the thick-target method for the measurements of atomic inner-shell ionization cross-section or X-ray production cross-section by keV electron impact. We find that in the processes of electron impact on the thick targets, the ratios of the characteristic X-ray yields of photoelectric ionization by bremsstrahlung to the total characteristic X-ray yields are Z-dependent and shell-dependent, and the ratios also show the weak energy-dependence. In addition, in the lower incident energy region (i.e. U < 5-6), the contribution from the rediffusion effect and the secondary electrons can be negligible. In general, the thick-target method can be appropriately applied to the measurements of atomic inner-shell ionization cross-sections or X-ray production cross-sections by electron impact for low and medium Z elements in the lower incident electron energy (i.e. U < 5-6). The experimental accuracies by the thick-target method can reach to the level equivalent or superior to the accuracies of experimental data based on the thin-target method. This thick-target method has been applied to the measurement of K-shell ionization cross-sections of Ni element by electron impact in this paper

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)

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

Heavy ion particle beam interaction with a hot ionized target

International Nuclear Information System (INIS)

Dei-Cas, R.; Bardy, J.; Beuve, M.A.; Laget, J.P.; Menier, A.; Renaud, M.

1983-03-01

The present status of the experimental facility consisting of a heavy ion beam travelling through a laser created plasma target is described. Some aspects such as laser-tandem coupling, beam performances, constraints on the plasma parameter ranges, plasma and beam diagnostics are analyzed

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

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

Progress Toward Heavy Ion IFE

International Nuclear Information System (INIS)

Meier, W.R.; Logan, B.G.; Waldron, W.L.; Sabbi, G.L.; Callahan-Miller, D.A.; Peterson, P.F.; Goodin, D.T.

2002-01-01

Successful development of Heavy Ion Fusion (HIF) will require scientific and technology advances in areas of targets, drivers and chambers. Design work on heavy ion targets indicates that high gain (60-130) may be possible with a -3-6 MJ driver depending on the ability to focus the beams to small spot sizes. Significant improvements have been made on key components of heavy ion drivers, including sources, injectors, insulators and ferromagnetic materials for long-pulse induction accelerator cells, solid-state pulsers, and superconducting quadrupole magnets. The leading chamber concept for HIF is the thick-liquid-wall HYLEE-II design, which uses an array of flibe jets to protect chamber structures from x-ray, debris, and neutron damage. Significant progress has been made in demonstrating the ability to create and control the types of flow needed to form the protective liquid blanket. Progress has also been made on neutron shielding for the final focus magnet arrays with predicted lifetimes now exceeding the life of the power plant. Safety analyses have been completed for the HYLEE-II design using state-of-the-art codes. Work also continues on target fabrication and injection for HE. A target injector experiment capable of > 5 Hz operation has been designed and construction will start in 2002. Methods for mass production of hohlraum targets are being evaluated with small-scale experiments and analyses. Progress in these areas will be reviewed

Progress toward heavy-ion IFE

International Nuclear Information System (INIS)

Meier, W.R.; Logan, B.G.; Waldron, W.L.; Sabbi, G.-L.; Callahan, D.A.; Peterson, P.F.; Goodin, D.T.

2002-01-01

Successful development of heavy-ion fusion (HIF) will require scientific and technology advances in areas of targets, drivers and chambers. Design work on heavy-ion targets indicates that high gain (60-130) may be possible with a ∼3-6 MJ driver depending on the ability to focus the beams to small spot sizes. Significant improvements have been made on key components of heavy-ion drivers, including sources, injectors, insulators and ferromagnetic materials for long-pulse induction accelerator cells, solid-state pulsers, and superconducting quadrupole magnets. The leading chamber concept for HIF is the thick-liquid-wall HYLIFE-II design, which uses an array of flibe jets to protect chamber structures from X-ray, debris, and neutron damage. Significant progress has been made in demonstrating the ability to create and control the types of flow needed to form the protective liquid blanket. Progress has also been made on neutron shielding for the final focus magnet arrays with predicted lifetimes now exceeding the life of the power plant. Safety analyses have been completed for the HYLIFE-II design using state-of-the-art codes. Work also continues on target fabrication and injection for HIF. A target injector experiment capable of >5 Hz operation has been designed and construction will start in 2002. Methods for mass-production of hohlraum targets are being evaluated with small-scale experiments and analyses. Progress in these areas will be reviewed

Rotating target wheel system for super-heavy element production at ATLAS

CERN Document Server

Greene, J P; Falout, J; Janssens, R V F

2004-01-01

A new scattering chamber housing a large diameter rotating target wheel has been designed and constructed in front of the Fragment Mass Analyzer (FMA) for the production of very heavy nuclei (Z greater than 100) using beams from the Argonne Tandem Linear Accelerator System (ATLAS). In addition to the target and drive system, the chamber is extensively instrumented in order to monitor target performance and deterioration. Capabilities also exist to install rotating entrance and exit windows for gas cooling of the target within the scattering chamber. The design and initial tests are described.

Automated computer analysis of x-ray radiographs greatly facilitates measurement of coating-thickness variations in laser-fusion targets

International Nuclear Information System (INIS)

Stupin, D.M.; Moore, K.R.; Thomas, G.D.; Whitman, R.L.

1981-01-01

An automated system was built to analyze x-ray radiographs of laser fusion targets which greatly facilitates the detection of coating thickness variations. Many laser fusion targets reqire opaque coatings 1 to 20 μm thick which have been deposited on small glass balloons 100 to 500 μm in diameter. These coatings must be uniformly thick to 1% for the targets to perform optimally. Our system is designed to detect variations as small as 100 A in 1-μm-thick coatings by converting the optical density variations of contact x-ray radiographs into coating thickness variations. Radiographic images are recorded in HRP emulsions and magnified by an optical microscope, imaged onto television camera, digitized and processed on a Data General S/230 computer with a code by Whitman. After an initial set-up by the operator, as many as 200 targets will be automatically characterized

[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.

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%

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.

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.

Extended methods using thick-targets for nuclear reaction data of radioactive isotopes

Science.gov (United States)

Ebata, Shuichiro; Aikawa, Masayuki; Imai, Shotaro

2017-09-01

The nuclear transmutation is a technology to dispose of radioactive wastes. However, we do not have enough basic data for its developments, such as thick-target yields (TTY) and the interaction cross sections for radioactive material. We suggest two methods to estimate the TTY using inverse kinematics and to obtain the excitation function of the interaction cross sections which is named the thick-target transmission (T3) method. We deduce the energy-dependent conversion relation between the TTYs of the original system and its inverse kinematics, which can be replaced to a constant coefficient in the high energy region. Furthermore we show the usefulness of the T3 method to investigate the excitation function of the 12C + 27Al reaction in the simulation.

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.)

Migration of trace heavy metals at the sea water/sediment interface

International Nuclear Information System (INIS)

Terada, Kikuo; Tomiyama, Chisato

1984-01-01

Migration behavior of some trace heavy metals such as Co(II), Cu(II), Mn(II) and Zn(II) at the sea water/sediment interface was investigated by tank experiments. The sea water which was doped with these metal ions (ppb to ppm levels) allowed to contact with the raw-, ignited- and autoclaved-marine sediments and the change of the concentration of each metal was traced at definite time intervals. At the end of the experiments, a core sample of the sediment was taken and analyzed for each metal in every 1 mm thick segment. On the other hand, the surface sediment was submitted to partial extraction with various kinds of reagents to estimate the chemical species of the metals captured in the sediment. While every metal ion was quickly adsorbed on surface of the raw sediment, a concentration gradient from surface to bottom of the water phase occurred in the ignited sediment system. The migration of manganese to the sediment phase was assumed to be concerned with bacterial activity in the sediment. Copper and zinc seemed to be adsorbed very quickly onto some fine sediment particles by the formation of organometallic complexes with some organic materials existing in the sediments. Cobalt migrated relatively fast downward within the sediment phase after its deposition. (author)

Experimental results on 2-30 keV bremsstrahlung from thick and thin targets

Energy Technology Data Exchange (ETDEWEB)

Shanker, R. [Atomic Physics Laboratory, Physics Department, Banaras Hindu University, Varanasi 221005 (India)]. E-mail: rshanker@bhu.ac.in

2006-10-15

The recent experimental investigations on electron bremsstrahlung produced from impact of 2-30 keV electrons with thick solid and thin gaseous targets are reviewed. The theoretical models describing the energy and angular distributions of bremsstrahlung photons are discussed with their brief outlines and formulations to explain the experimental data. The results on thick target bremsstrahlung (TTB) spectra produced by keV electrons have suggested that there is a need to develop a comprehensive theory for accounting the solid state effects. It is further noted that the prediction of the modified KKD formula gives a reasonable agreement with the TTB data, whereas a semi-empirical formula gives a better fit to the data for thick targets. The available experimental data for dependence of double differential cross-sections of emitted photons on impact energy and their emission angles for gaseous atoms and molecules exhibit a good agreement with the theoretical calculations of Kissel et al., [1983. Shape functions for atomic-field bremsstrahlung from electrons of kinetic energy 1-500 keV on selected neutral atoms 1

Accumulation of Long-lived activity in heavy metal liquid targets

International Nuclear Information System (INIS)

Shubin, Y. N.; Gai, E. V.; Ignatyuk, A. V.; Lunev, V. P.

1997-01-01

The calculations and analysis of the accumulation of radioactive nuclei and long-lived activity in heavy metal liquid targets were performed. The dominating contributions to the total radioactivity of radionuclides resulting from fission, spallation reactions and radiative capture by target nuclei for various irradiation and cooling times were calculated and analyzed. The most important parts of neutron and proton spectra were determined that give the dominant contributions to the total and partial activity of the targets. The contributions of fission products to the target activity and partial activities of main long-lived fission products were evaluated. The results of the calculations are compared with the data on Energy Amplifier Project. (Author) 12 refs

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)

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

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)

Enhanced electron capture by fast heavy di-clusters exciting solids

International Nuclear Information System (INIS)

Cooney, P.J.; Faibis, A.; Kanter, E.P.; Koenig, W.; Maor, D.; Zabransky, B.J.

1985-01-01

The authors have studied the dependence of the charge-state-distributions of heavy-ion fragments resulting from the foil-induced dissociation of 4.2-MeV N 2 + ions on the thickness of the carbon target foil. The results were compared to those distributions measured for impact of 2.1-MeV N + projectiles. Whereas the charge-state distributions for atomic ion impact are already equilibrated in the thinnest targets used (2 μg/cm 2 ), those measured for molecular ion impact are strongly dependent on the target thickness, even for the thickest targets (100 + g/cm 2 ). The distributions for molecular-ion impact show a marked shift towards lower charge states, evidencing an enhanced electron capture probability over the case of monatomic ion impact. A quantitative model was developed to explain this phenomenon

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

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 ...

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.

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.

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.

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

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.)

Study of charge exchanges of heavy ions passing through solids

International Nuclear Information System (INIS)

Baron, Eric.

1975-01-01

The charge state distributions of 1 to 6MeV/nucleon heavy ions (from oxygen to krypton) passing through thin targets of various materials (C, Cu, Ag, Au) are studied. The variation of the average charge state and of the charge state fractions as a function of the thickness of carbon targets ranging from zero to the equilibrium thickness is measured; this allows the calculation of effective cross-sections of the charge changing process. It is also shown that the lower the target atomic number, the higher the average charge state, which is explained by a decrease of the capture cross sections. Finally, a semi-empirical formula predicting the average charge state is proposed, as an extension of Betz's and Nikolaev and Dmitriev's formula [fr

Technique for thick polymer coating of inertial-confinement-fusion targets

International Nuclear Information System (INIS)

Lee, M.C.; Feng, I.; Wang, T.G.; Kim, H.

1983-01-01

A novel technique has been developed to coat a thick layer (15--50 μm) of polymer materials on inertial-confinement-fusion (ICF) targets. In this technique, the target and the coating material are independently positioned and manipulated. The coating material is first dissolved in an appropriate solvent to form a polymer solution. The solution is then atomized, transported, and allowed to coalesce into a droplet in a stable acoustic levitating field. The ICF target mounted on a stalk is moved into the acoustic field by manipulating a three-dimensional (3-D) positioner to penetrate the surface membrane of the droplet and thus the target is immersed in the levitated coating solution. The 3-D coordinates of the target inside the droplet are obtained using two orthogonally placed television cameras. The target is positioned at the geometric center of the droplet and maintained at that location by continuously manipulating the 3-D device until the coating layer is dried. Tests of this technique using a polymer solution have been highly successful

Thin-thick hydrogen target for nuclear physics

Energy Technology Data Exchange (ETDEWEB)

Gheller, J.-M.; Juster, F.-P.; Authelet, G. [CEA Saclay, Irfu/SACM, F-91191 Gif-Sur-Yvette cedex (France); Vinyar, I. [PELIN Limited Liability Company 27 A, Gzhatskaya Str, office 103 St. Petersbourg 195220 (Russian Federation); Relland, J. [CEA Saclay, Irfu/SIS, F-91191 Gif-Sur-Yvette cedex (France); Commeaux, C. [Institut de Physique Nucléaire, campus Universitaire-Bat 103, 91406 Orsay cedex (France)

2014-01-29

In spectroscopic studies of unstable nuclei, hydrogen targets are of key importance. The CHyMENE Project aims to provide to the nuclear physics community a thin and pure solid windowless hydrogen or deuterium target. CHyMENE project must respond to this request for the production of solid Hydrogen. The solid hydrogen target is produced in a continuous flow (1 cm/s) by an extrusion technique (developed with the PELIN laboratory) in a vacuum chamber. The shape of the target is determined by the design of the nozzle at the extrusion process. For the purpose, the choice is a rectangular shape with a width of 10 mm and a thickness in the range of 30-50 microns necessary for the physics objectives. The cryostat is equipped with a GM Cryocooler with sufficient power for the solidification of the hydrogen in the lower portion of the extruder. In the higher part of the cryostat, the hydrogen gas is first liquefied and partially solidified. It is then compressed at 100 bars in the cooled extruder before expulsion of the film through the nozzle at the center of the reaction vacuum chamber. After the previous step, the solid hydrogen ribbon falls by gravity into a dedicated chamber where it sublimes and the gas is pumped and evacuated in a exhaust line. This paper deals with the design of the cryostat with its equipment, with the sizing of the thermal bridge (Aluminum and copper), with the results regarding the contact resistance as well as with the vacuum computations of the reaction and recovery hydrogen gas chambers.

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)

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 ...

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

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.

Photo-neutron yields from thin and thick targets irradiated by 2.0 GeV electrons

International Nuclear Information System (INIS)

Hee-Seock, Lee; Syuichi, Ban; Toshiya, Sanami; Kazutoshi, Takahashi; Tatsuhiko, Sato; Kazuo, Shin

2005-01-01

The photo-neutron yields from thin and thick targets irradiated by high energy electrons were studied. The photo-neutron spectra at 90 deg C relative to the incident 2.0 GeV electrons were measured by the pulsed beam time-of-flight technique using the Pilot-U plastic scintillator and the NE213 liquid scintillator with 2 inches in length and 2 inches in diameter. Targets, from low-Z element (carbon) to high-Z element (bismuth) and with thin (0.5 Xo) and thick (10 Xo) thickness, were used in this study. The differential photo-neutron yields between 2 MeV (mainly 8 MeV) and 400 MeV were obtained. The systematics was studied to make empirical yield terms for shielding application. Recently, the study of the angular distributed yields was conducted at two other observing angles, 48 deg C and 140 deg C. The photo-neutron yields between 8 MeV and 250 MeV were obtained for thick targets. The experimental data were compared with results calculated using the EGS4+PICA3 or the MCNPX 2.5d code. (authors)

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

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

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.)

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

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 ...

Role of laser contrast and foil thickness in target normal sheath acceleration

Energy Technology Data Exchange (ETDEWEB)

Gizzi, L.A. [ILIL, Istituto Nazionale di Ottica, CNR, Via G. Moruzzi 1, Pisa (Italy); INFN Sezione di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy); Altana, C. [Dipartimento di Fisica e Astronomia, Università degli Studi di Catania (Italy); Laboratori Nazionali del Sud, INFN, Via S. Sofia, Catania (Italy); Brandi, F. [ILIL, Istituto Nazionale di Ottica, CNR, Via G. Moruzzi 1, Pisa (Italy); Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova (Italy); Cirrone, P. [Laboratori Nazionali del Sud, INFN, Via S. Sofia, Catania (Italy); Cristoforetti, G. [ILIL, Istituto Nazionale di Ottica, CNR, Via G. Moruzzi 1, Pisa (Italy); Fazzi, A. [Energy Department, Polytechnic of Milan, Milan (Italy); INFN, Milan (Italy); Ferrara, P.; Fulgentini, L. [ILIL, Istituto Nazionale di Ottica, CNR, Via G. Moruzzi 1, Pisa (Italy); Giove, D. [INFN-LASA, Via Fratelli Cervi 201, 20090 Segrate (Italy); Koester, P. [ILIL, Istituto Nazionale di Ottica, CNR, Via G. Moruzzi 1, Pisa (Italy); Labate, L. [ILIL, Istituto Nazionale di Ottica, CNR, Via G. Moruzzi 1, Pisa (Italy); INFN Sezione di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy); Lanzalone, G. [Laboratori Nazionali del Sud, INFN, Via S. Sofia, Catania (Italy); Università degli Studi di Enna Kore, Via delle Olimpiadi, 94100 Enna (Italy); Londrillo, P. [INAF–Osservatorio astronomico Bologna (Italy); Mascali, D.; Muoio, A. [Laboratori Nazionali del Sud, INFN, Via S. Sofia, Catania (Italy); Palla, D. [ILIL, Istituto Nazionale di Ottica, CNR, Via G. Moruzzi 1, Pisa (Italy); INFN Sezione di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy); Dipartimento di Fisica, Università di Pisa (Italy); Schillaci, F. [Laboratori Nazionali del Sud, INFN, Via S. Sofia, Catania (Italy); Sinigardi, S. [Dipartimento di Fisica e Astronomia, Università di Bologna, Bologna (Italy); INFN, Sez. di Bologna, Via Irnerio 46, 40126 Bologna (Italy); and others

2016-09-01

In this paper we present an experimental investigation of laser driven light-ion acceleration using the ILIL laser at an intensity of 2×10{sup 19} W/cm{sup 2}. In the experiment we focused our attention on the identification of the role of target thickness and resistivity in the fast electron transport and in the acceleration process. Here we describe the experimental results concerning the effect of laser contrast in the laser–target interaction regime. We also show preliminary results on ion acceleration which provide information about the role of bulk target ions and surface ions and target dielectric properties in the acceleration process.

An Updated Point Design for Heavy Ion Fusion

International Nuclear Information System (INIS)

Yu, S.S.; Meier, W.R.; Abbott, R.B.; Barnard, J.J.; Brown, T.; Callahan, D.A.; Heitzenroeder, P.; Latkowski, J.F.; Logan, B.G.; Pemberton, S.J.; Peterson, P.F.; Rose, D.V.; Sabbi, G.L.; Sharp, W.M.; Welch, D.R.

2002-01-01

An updated, self-consistent point design for a heavy ion fusion (HIF) power plant based on an induction linac driver, indirect-drive targets, and a thick liquid wall chamber has been completed. Conservative parameters were selected to allow each design area to meet its functional requirements in a robust manner, and thus this design is referred to as the Robust Point Design (RPD-2002). This paper provides a top-level summary of the major characteristics and design parameters for the target, driver, final focus magnet layout and shielding, chamber, beam propagation to the target, and overall power plant

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

Amended Results for Hard X-Ray Emission by Non-thermal Thick Target Recombination in Solar Flares

Science.gov (United States)

Reep, J. W.; Brown, J. C.

2016-06-01

Brown & Mallik and the corresponding corrigendum Brown et al. presented expressions for non-thermal recombination (NTR) in the collisionally thin- and thick-target regimes, claiming that the process could account for a substantial part of the hard X-ray continuum in solar flares usually attributed entirely to thermal and non-thermal bremsstrahlung (NTB). However, we have found the thick-target expression to become unphysical for low cut-offs in the injected electron energy spectrum. We trace this to an error in the derivation, derive a corrected version that is real-valued and continuous for all photon energies and cut-offs, and show that, for thick targets, Brown et al. overestimated NTR emission at small photon energies. The regime of small cut-offs and large spectral indices involve large (reducing) correction factors but in some other thick-target parameter regimes NTR/NTB can still be of the order of unity. We comment on the importance of these results to flare and microflare modeling and spectral fitting. An empirical fit to our results shows that the peak NTR contribution comprises over half of the hard X-ray signal if δ ≳ 6{≤ft(\\tfrac{{E}0c}{4{keV}}\\right)}0.4.

Effect of Insulation Thickness on Thermal Stratification in Hot Water Tanks

Directory of Open Access Journals (Sweden)

Burak KURŞUN

2018-03-01

Full Text Available One of the important factors to be considered in increasing the efficiency of hot water storage tanks used for thermal energy storage is thermal stratification. Reducing the temperature of the water at the base of the tank provides more utilization of the energy of the heat source during the heating of the water and improves the efficiency of the system. In this study, the effect of the insulation thickness on the outer surface of the tank and the ratio of the tank diameter to the height (D/H on the thermal stratification was investigated numerically. Numerical analyzes were carried out for the condition that the insulation thickness was constant and variable in the range of D/H=0,3-1. Water was used as the heat storage fluid and the analysis results were obtained for eight hours cooling period. Numerical results showed that the temperature difference between the bottom and top surfaces of the tank increased between 7-9 ° C for the range of D / H = 0,3-1 with changing the insulation thickness.

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

Nonuniformity mitigation of beam illumination in heavy ion inertial fusion

International Nuclear Information System (INIS)

Kawata, S; Noguchi, K; Suzuki, T; Kurosaki, T; Barada, D; Ogoyski, A I; Zhang, W; Xie, J; Zhang, H; Dai, D

2014-01-01

In inertial fusion, a target DT fuel should be compressed to typically 1000 times the solid density. The target implosion nonuniformity is introduced by a driver beam’s illumination nonuniformity, for example. The target implosion should be robust against the implosion nonuniformities. In this paper, the requirement for implosion uniformity is first discussed. The implosion non-uniformity should be less than a few percent. The implosion dynamics is also briefly reviewed in heavy ion inertial fusion (HIF). Heavy ions deposit their energy inside the target energy absorber, and the energy deposition layer is rather thick, depending on the ion particle energy. Then nonuniformity mitigation mechanisms of the heavy ion beam (HIB) illumination in HIF are discussed. A density valley appears in the energy absorber, and the large-scale density valley also works as a radiation energy confinement layer, which contributes to a radiation energy smoothing. In HIF, wobbling heavy ion beam illumination was also introduced to realize a uniform implosion. The wobbling HIB axis oscillation is precisely controlled. In the wobbling HIBs’ illumination, the illumination nonuniformity oscillates in time and space on an HIF target. The oscillating-HIB energy deposition may contribute to the reduction of the HIBs’ illumination nonuniformity by its smoothing effect on the HIB illumination nonuniformity and also by a growth mitigation effect on the Rayleigh–Taylor instability. (invited comment)

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)

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)

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...

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

Fracture analysis of axially cracked pressure tube of pressurized heavy water reactor

International Nuclear Information System (INIS)

Krishnan, S.; Bhasin, V.; Mahajan, S.C.

1997-01-01

Three Dimensional (313) finite element elastic plastic fracture analysis was done for through wall axially cracked thin pressure tubes of 220 MWe Indian Pressurized Heavy Water Reactor. The analysis was done for Zr-2 and Zr-2.5Nb pressure tubes operating at 300 degrees C and subjected to 9.5 Mpa internal pressure. Critical crack length was determined based on tearing instability concept. The analysis included the effect of crack face pressure due to the leaking fluid from tube. This effect was found to be significant for pressure tubes. The available formulae for calculating J (for axially cracked tubes) do not take into account the effect of crack face pressure. 3D finite element analysis also gives insight into variation of J across the thickness of pressure tube. It was observed that J is highest at the mid-surface of tube. The results have been presented in the form of across the thickness average J value and a peak factor on J. Peak factor on J is ratio of J at mid surface to average J value. Crack opening area for different cracked lengths was calculated from finite element results. The fracture assessment of pressure tubes was also done using Central Electricity Generating Board R-6 method. Ductile tearing was considered

Fracture analysis of axially cracked pressure tube of pressurized heavy water reactor

Energy Technology Data Exchange (ETDEWEB)

Krishnan, S.; Bhasin, V.; Mahajan, S.C. [Bhabha Atomic Research Centre, Bombay (India)] [and others

1997-04-01

Three Dimensional (313) finite element elastic plastic fracture analysis was done for through wall axially cracked thin pressure tubes of 220 MWe Indian Pressurized Heavy Water Reactor. The analysis was done for Zr-2 and Zr-2.5Nb pressure tubes operating at 300{degrees}C and subjected to 9.5 Mpa internal pressure. Critical crack length was determined based on tearing instability concept. The analysis included the effect of crack face pressure due to the leaking fluid from tube. This effect was found to be significant for pressure tubes. The available formulae for calculating J (for axially cracked tubes) do not take into account the effect of crack face pressure. 3D finite element analysis also gives insight into variation of J across the thickness of pressure tube. It was observed that J is highest at the mid-surface of tube. The results have been presented in the form of across the thickness average J value and a peak factor on J. Peak factor on J is ratio of J at mid surface to average J value. Crack opening area for different cracked lengths was calculated from finite element results. The fracture assessment of pressure tubes was also done using Central Electricity Generating Board R-6 method. Ductile tearing was considered.

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)

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

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.

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)

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

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)

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

The α-induced thick-target γ-ray yield from light elements

Energy Technology Data Exchange (ETDEWEB)

Heaton, R. K. [Queen`s Univ., Kingston, ON (Canada). Dept. of Physics

1994-10-01

The α-induced thick-target γ-ray yield from light elements has been measured in the energy range 5.6 MeV ≤ E_α ≤ 10 MeV. The γ-ray yield for > 2.1 MeV from thick targets of beryllium, boron nitride, sodium fluoride, magnesium, aluminum and silicon were measured using the α-particle beam from the Lawrence Berkeley Laboratories 88 in. cyclotron. The elemental yields from this experiment were used to construct the α-induced direct production γ-ray spectrum from materials in the SNO detector, a large volume ultra-low background neutrino detector located in the Creighton mine near Sudbury, Canada. This background source was an order of magnitude lower than predicted by previous calculations. These measurements are in good agreement with theoretical calculations of this spectrum based on a statistical nuclear model of the reaction, with the gross high energy spectrum structure being reproduced to within a factor of two. Detailed comparison of experimental and theoretical excitation population distribution of several residual nuclei indicate the same level of agreement within experimental uncertainties.

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

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

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)

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 ...

Development of sea water pipe thickness measurement technique

International Nuclear Information System (INIS)

Morimoto, Kazuo; Wakayama, Seiichi; Takeuchi, Iwao; Masamori, Sigero; Yamasita, Takesi.

1995-01-01

In nuclear and thermal power plants, wall wear of sea water pipes is reported to occur in the inner surface due to corrosion and erosion. From the viewpoint of improving the equipments reliability, it is desirable that wall thickness should be measured from the outer surface of the pipe during operation. In the conventional method, paint on the outer surface of the pipe was locally removed at each point of a 20 by 50 mm grid, and inspection was carried out at these spots. However, this method had some problems, such as (1) it was necessary to replace the paint, and (2) it was difficult to obtain the precise distribution of wall thickness. Therefore, we have developed a wall thickness measuring system which has the following features. (1) It is possible to perform inspection from the outer surface without removing paint during operation. (2) It is possible to measure the distribution of wall thickness and display it as color contour map simultaneously. (3) The work of inspectors can be alleviated by the automatic recording of measured data. (author)

Characterization of a multi-keV x-ray source produced by nanosecond laser irradiation of a solid target: The influence of laser focus spot and target thickness

International Nuclear Information System (INIS)

Hu Guangyue; Zheng Jian; Shen Baifei; Lei Anle; Xu Zhizhan; Liu Shenye; Zhang Jiyan; Yang Jiamin; Ding Yongkun; Hu Xin; Huang Yixiang; Du Huabing; Yi Rongqing

2008-01-01

The influence of focus spot and target thickness on multi-keV x-ray sources generated by 2 ns duration laser heated solid targets are investigated on the Shenguang II laser facility. In the case of thick-foil targets, the experimental data and theoretical analysis show that the emission volume of the x-ray sources is sensitive to the laser focus spot and proportional to the 3 power of the focus spot size. The steady x-ray flux is proportional to the 5/3 power of the focus spot size of the given laser beam in our experimental condition. In the case of thin-foil targets, experimental data show that there is an optimal foil thickness corresponding to the given laser parameters. With the given laser beam, the optimal thin-foil thickness is proportional to the -2/3 power of the focus spot size, and the optimal x-ray energy of thin foil is independent of focus spot size

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)

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.)

Studies on radiation symmetrization in heavy-ion driven hohlraum targets

International Nuclear Information System (INIS)

Temporal, M.; Atzeni, S.

1993-01-01

Radiation symmetrization within spherical, ellipsoidal and cylindral hohlraum targets for heavy ion inertial confinement fusion (ICF) is studied by means of a 3-D numerical, static model, in which realistic assumptions are made concerning the geometry of the system and, particularly, of the radiation converters. Among the systems so far studied, only spherical hohlraums with six converters achieve the illumination symmetry of the fusion capsule considered necessary for ICF applications. A parametric study of cylindrical hohlraums enlightens the effect of several parameter changes, and suggests directions for further studies, aiming at the design of two-converter targets

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

Thickness profile measuring device for rolling metal bands or sheets

International Nuclear Information System (INIS)

Campas, J.J.; Terreaux, S.

1995-01-01

Previous radiometric thickness gages were affected by insufficient water proofing and limited cooling performances for the detection subsystem (in general specially designed photodiodes). This resulted in poor reliability and life expectancy, in particular when heavy humidity and constant radiative heat are present as for hot rolling in the metal industry. This new gage design brings enhanced performances for these two factors. (D.L.). 4 refs., 3 figs

An on-line tritium-in-water monitor

International Nuclear Information System (INIS)

Singh, A.N.; Ratnakaran, M.; Vohra, K.G.

1985-01-01

The paper describes the development and operation of a continuous on-line tritium-in-water monitor for the detection of heavy water leaks into the secondary coolant light water of a heavy water power reactor. The heart of the instrument is its plastic scintillator sponge detector, made from 5 μm thick plastic scintillator films. The sponge weighs only about 1 g and is in the form of disc of 48 mm diameter and 8 mm thickness. The total surface area of the films is about 3000 cm 2 . In the coincidence mode of counting, the detector gives 1000 cps for the passage of 3.7 x 10 4 Bq/cm 3 (1 μCi/cm 3 ) of tritiated water. The background in 6 cm thick lead shielding in the laboratory is 0.2 cps, and inside the reactor building it is below 1 cps. The monitor presently scans 18 sample lines in sequence for 5 min each and gives a printout for the activity in each line. (orig.)

An on-line tritium-in-water monitor

Science.gov (United States)

Singh, A. N.; Ratnakaran, M.; Vohra, K. G.

1985-05-01

The paper describes the development and operation of a continuous on-line tritium-in-water monitor for the detection of heavy water leaks into the secondary coolant light water of a heavy water power reactor. The heart of the instrument is its plastic scintillator sponge detector, made from 5 μm thick plastic scintillator films. The sponge weighs only about 1 g and is in the form of disc of 48 mm diameter and 8 mm thickness. The total surface area of the films is about 3000 cm 2. In the coincidence mode of counting, the detector gives 1000 cps for the passage of 3.7 × 10 4 Bq/cm 3 (1 μCi/cm 3) of tritiated water. The background in 6 cm thick lead shielding in the laboratory is 0.2 cps, and inside the reactor building it is below 1 cps. The monitor presently scans 18 sample lines in sequence for 5 min each and gives a printout for the activity in each line.

Windowless gas target with gas-dynamical focussing of an ultrasonic neutral gas flow

International Nuclear Information System (INIS)

Tietsch, W.; Bethge, K.; Feist, H.; Schopper, E.

1975-11-01

The construction of a gas jet target for heavy ion reaction is reported on. The spatial compression strockwaves in a supersonic flow behind a laval nozzle are used as a target. The target thickness can be varied by the choice of the nozzle pressure and the static pressure in the expansion room. All gases can be used. (WL) [de

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)

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.

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

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

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)

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)

Design of electric-field assisted surface plasmon resonance system for the detection of heavy metal ions in water

Energy Technology Data Exchange (ETDEWEB)

Kyaw, Htet Htet [Department of Physics, College of Science, Sultan Qaboos University, P. O. Box 36, Al-Khoud 123 (Oman); Boonruang, Sakoolkan, E-mail: sakoolkan.boonruang@nectec.or.th, E-mail: waleed.m@bu.ac.th [Photonics Technology Laboratory, National Electronics and Computer Technology Center (NECTEC), 112 Thailand Science Park, PathumThani 12120 (Thailand); Mohammed, Waleed S., E-mail: sakoolkan.boonruang@nectec.or.th, E-mail: waleed.m@bu.ac.th [Center of Research in Optoelectronics, Communication and Control Systems (BUCROCCS), School of Engineering, Bangkok University, PathumThani 12120 (Thailand); Dutta, Joydeep [Functional Materials Division, School of Information and Communication Technology, KTH Royal Institute of Technology, Isafjordsgatan 22, SE-164 40 Kista, Stockholm (Sweden)

2015-10-15

Surface Plasmon Resonance (SPR) sensors are widely used in diverse applications. For detecting heavy metal ions in water, surface functionalization of the metal surface is typically used to adsorb target molecules, where the ionic concentration is detected via a resonance shift (resonance angle, resonance wavelength or intensity). This paper studies the potential of a possible alternative approach that could eliminate the need of using surface functionalization by the application of an external electric field in the flow channel. The exerted electrical force on the ions pushes them against the surface for enhanced adsorption; hence it is referred to as “Electric-Field assisted SPR system”. High system sensitivity is achieved by monitoring the time dynamics of the signal shift. The ion deposition dynamics are discussed using a derived theoretical model based on ion mobility in water. On the application of an appropriate force, the target ions stack onto the sensor surface depending on the ionic concentration of target solution, ion mass, and flow rate. In the experimental part, a broad detection range of target cadmium ions (Cd{sup 2+}) in water from several parts per million (ppm) down to a few parts per billion (ppb) can be detected.

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.

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.

(p,γ) reaction on thick target as a spectroscopic tool

International Nuclear Information System (INIS)

Paradellis, T.

1985-01-01

When thick even-even targets around mass A-60 are bombarded with low energy protons the (p,γ) reaction excite a large number of resonances in the compound nucleus with a strong initial alignment. The statistical gamma decay of these states to the low lying discrete levels of the compound nucleus introduces some attenuation of the initial alignment. It is shown experimentally that the resulting alignment of the low discrete states is strong enough to permit usefull spectroscopic study of these states, since the resulting attenuation do not depend on the target or the bombarding energy being function of the spin of the level. This type of spectroscopy can be extended also to measure life-time of levels through Doppler-shift

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

Verification of the hydraulic design of the FMIT liquid lithium target

International Nuclear Information System (INIS)

Miles, R.R.; Annese, C.E.; Ingham, J.G.

1983-01-01

A liquid lithium target is being developed to generate a neutron flux for material testing in a fusion-like environment. The target consists of a thin, high speed, curved wall jet of lithium which is formed by an asymmetric nozzle. A prototype target was designed using potential flow analysis and was tested in water. Measurements of jet thickness and velocity in water and thickness in lithium were compared with isothermal design predictions and were shown to match within 1% for thickness and 5% for jet velocity

Spectroscopic studies with the use of deep-inelastic heavy-ion reactions

International Nuclear Information System (INIS)

Broda, R

2006-01-01

Gamma spectroscopic studies exploiting deep-inelastic heavy-ion reactions in thick target experiments are reviewed. The description of physical motivation, history of early experiments, analysis of the N/Z equilibration process as well as the outline of the experimental method and data analysis are followed by the presentation of main results obtained in various regions of the nuclide chart. Brief comments on thin target spectroscopy experiments involving fragment detection and future outlook are summarized. (topical review)

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

Simulation of multiple scattering background in heavy ion backscattering spectrometry

International Nuclear Information System (INIS)

Li, M.M.; O'Connor, D.J.

1999-01-01

With the development of heavy ion backscattering spectrometry (HIBS) for the detection of trace quantities of heavy-atom impurities on Si surfaces, it is necessary to quantify the multiple scattering contribution to the spectral background. In the present work, the Monte Carlo computer simulation program TRIM has been used to study the backscattering spectrum and the multiple scattering background features for heavy ions C, Ne, Si, Ar and Kr impinging on four types of targets: (1) a single ultra-thin (free standing) Au film of 10 A thickness, (2) a 10 A Au film on a 50 A Si surface, (3) a 10 A Au film on an Si substrate (10 000 A), and (4) a thick target (10 000 A) of pure Si. The ratio of the signal from the Au thin layer to the background due to multiple scattering has been derived by fitting the simulation results. From the simulation results, it is found that the Au film contributes to the background which the Si plays a role in developing due to the ion's multiple scattering in the substrate. Such a background is generated neither by only the Au thin layer nor by the pure Si substrate independently. The corresponding mechanism of multiple scattering in the target can be explained as one large-angle scattering in the Au layer and subsequently several small angle scatterings in the substrate. This study allows an appropriate choice of incident beam species and energy range when the HIBS is utilized to analyse low level impurities in Si wafers

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.

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).

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

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

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 ...

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.

Significant Features of Warm Season Water Vapor Flux Related to Heavy Rainfall and Draught in Japan

Science.gov (United States)

Nishiyama, Koji; Iseri, Yoshihiko; Jinno, Kenji

2009-11-01

In this study, our objective is to reveal complicated relationships between spatial water vapor inflow patterns and heavy rainfall activities in Kyushu located in the western part of Japan, using the outcomes of pattern recognition of water vapor inflow, based on the Self-Organizing Map. Consequently, it could be confirmed that water vapor inflow patterns control the distribution and the frequency of heavy rainfall depending on the direction of their fluxes and the intensity of Precipitable water. Historically serious flood disasters in South Kyushu in 1993 were characterized by high frequency of the water vapor inflow patterns linking to heavy rainfall. On the other hand, severe draught in 1994 was characterized by inactive frontal activity that do not related to heavy rainfall.

High-power spallation target using a heavy liquid metal free surface flow

International Nuclear Information System (INIS)

Litfin, K.; Fetzer, J.R.; Batta, A.; Class, A.G.; Wetzel, Th.

2015-01-01

A prototype of a heavy liquid metal free surface target as proposed for the multi-purpose hybrid research reactor for high-tech applications in Mol, Belgium, has been set up and experimentally investigated at the Karlsruhe Liquid Metal Laboratory. A stable operation was demonstrated in a wide range of operating conditions and the surface shape was detected and compared with numerical pre-calculations employing Star-CD. Results show a very good agreement of experiment and numerical predictions which is an essential input for other windowless target designs like the META:LIC target for the European Spallation Source. (author)

Tritium separation from heavy water by electrolysis with solid polymer electrolyte

International Nuclear Information System (INIS)

Ogata, Y.; Ohtani, N.; Kotaka, M.

2003-01-01

A tritium separation from heavy water by electrolysis using a solid polymer electrode layer was specified. The cathode was made of stainless steel or nickel. The electrolysis was performed for 1 hour at 5, 10, 20, and 30 deg C. Using a palladium catalyst, generated hydrogen and oxygen gases were recombined, which was collected with a cold trap. The activities of the samples were measured by a liquid scintillation counter. The apparent tritium separation factors of the heavy and light water at 20 deg C were ∼2 and ∼12, respectively. (author)

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

Removal of Heavy Metals from Drinking Water by Magnetic Carbon Nanostructures Prepared from Biomass

OpenAIRE

Muneeb Ur Rahman Khattak, Muhammad; Zahoor, Muhammad; Muhammad, Bakhtiar; Khan, Farhat Ali; Ullah, Riaz; AbdEI-Salam, Naser M.

2017-01-01

Heavy metals contamination of drinking water has significant adverse effects on human health due to their toxic nature. In this study a new adsorbent, magnetic graphitic nanostructures were prepared from watermelon waste. The adsorbent was characterized by different instrumental techniques (surface area analyzer, FTIR, XRD, EDX, SEM, and TG/DTA) and was used for the removal of heavy metals (As, Cr, Cu, Pb, and Zn) from water. The adsorption parameters were determined for heavy metals adsorpti...

Commissioning a Rotating Target Wheel Assembly for Heavy Element Studies

Science.gov (United States)

Fields, L. D.; Bennett, M. E.; Mayorov, D. A.; Folden, C. M.

2013-10-01

The heaviest elements are produced artificially by fusing nuclei of light elements within an accelerator to form heavier nuclei. The most direct method to increase the production rate of nuclei is to increase the beam intensity, necessitating the use of a rotating target to minimize damage to the target by deposited heat. Such a target wheel was constructed for heavy element research at Texas A&M University, Cyclotron Institute, consisting of a wheel with three banana-shaped target cutouts. The target is designed to rotate at 1700 rpm, and a fiber optic cable provides a signal to trigger beam pulsing in order to avoid irradiating the spokes between target segments. Following minor mechanical modifications and construction of a dedicated electrical panel, the rotating target assembly was commissioned for a beam experiment. A 15 MeV/u beam of 20Ne was delivered from the K500 cyclotron and detected by a ruggedized silicon detector. The beam pulsing response time was characterized as a function of the rational frequency of the target wheel. Preliminary analysis suggests that the K500 is capable of pulsing at rates of up to 250 Hz, which is sufficient for planned future experiments. Funded by DOE and NSF-REU Program.

Heavy mineral sorting in downwards injected Palaeocene sandstone, Siri Canyon, Danish North Sea

DEFF Research Database (Denmark)

Kazerouni, Afsoon Moatari; Friis, Henrik; Svendsen, Johan Byskov

2011-01-01

Post-depositional remobilization and injection of sand are often seen in deep-water clastic systems and has been recently recognised as a significant modifier of deep-water sandstone geometry. Large-scale injectite complexes have been interpreted from borehole data in the Palaeocene Siri Canyon...... of depositional structures in deep-water sandstones, the distinction between "in situ" and injected or remobilised sandstones is often ambiguous. Large scale heavy mineral sorting (in 10 m thick units) is observed in several reservoir units in the Siri Canyon and has been interpreted to represent the depositional...... sorting. In this study we describe an example of effective shear-zone sorting of heavy minerals in a thin downward injected sandstone dyke which was encountered in one of the cores in the Cecilie Field, Siri Canyon. Differences in sorting pattern of heavy minerals are suggested as a tool for petrographic...

Graphite-moderated and heavy water-moderated spectral shift controlled reactors

International Nuclear Information System (INIS)

Alcala Ruiz, F.

1984-01-01

It has been studied the physical mechanisms related with the spectral shift control method and their general positive effects on economical and non-proliferant aspects (extension of the fuel cycle length and low proliferation index). This methods has been extended to non-hydrogenous fuel cells of high moderator/fuel ratio: heavy water cells have been con- trolled by graphite rods graphite-moderated and gas-cooled cells have been controlled by berylium rods and graphite-moderated and water-cooled cells have been controlled by a changing mixture of heavy and light water. It has been carried out neutron and thermal analysis on a pre design of these types of fuel cells. We have studied its neutron optimization and their fuel cycles, temperature coefficients and proliferation indices. Finally, we have carried out a comparative analysis of the fuel cycles of conventionally controlled PWRs and graphite-moderated, water-cooled and spectral shift controlled reactors. (Author) 71 refs

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

Molecular dynamics simulations of ion range profiles for heavy ions in light targets

Energy Technology Data Exchange (ETDEWEB)

Lan, C. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States); State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 (China); Xue, J.M. [State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 (China); Zhang, Y., E-mail: Zhangy1@ornl.gov [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Morris, J.R. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Zhu, Z. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Gao, Y.; Wang, Y.G.; Yan, S. [State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 (China); Weber, W.J. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

2012-09-01

The determination of stopping powers for slow heavy ions in targets containing light elements is important to accurately describe ion-solid interactions, evaluate ion irradiation effects and predict ion ranges for device fabrication and nuclear applications. Recently, discrepancies of up to 40% between the experimental results and SRIM (Stopping and Range of Ions in Matter) predictions of ion ranges for heavy ions with medium and low energies (<{approx}25 keV/nucleon) in light elemental targets have been reported. The longer experimental ion ranges indicate that the stopping powers used in the SRIM code are overestimated. Here, a molecular dynamics simulation scheme is developed to calculate the ion ranges of heavy ions in light elemental targets. Electronic stopping powers generated from both a reciprocity approach and the SRIM code are used to investigate the influence of electronic stopping on ion range profiles. The ion range profiles for Au and Pb ions in SiC and Er ions in Si, with energies between 20 and 5250 keV, are simulated. The simulation results show that the depth profiles of implanted ions are deeper and in better agreement with the experiments when using the electronic stopping power values derived from the reciprocity approach. These results indicate that the origin of the discrepancy in ion ranges between experimental results and SRIM predictions in the low energy region may be an overestimation of the electronic stopping powers used in SRIM.

Physical and water properties of selected Polish heavy soils of various origins

Directory of Open Access Journals (Sweden)

Kaczmarek Zbigniew

2015-12-01

Full Text Available The paper presents the characteristics of selected physical, chemical, and water properties of four mineral arable soils characterized with heavy and very heavy texture. Soil samples from genetic horizons of black earths from areas near Kętrzyn, Gniew and Kujawy, and alluvial soils from Żuławy were used. The following properties were determined in the samples of undisturbed and disturbed structure: texture, particle density, bulk density, porosity, natural and hygroscopic moistures, maximal hygroscopic capacity, saturated hydraulic conductivity, potential of water bonding in soil, total and readily available water, total retention in the horizon of 0–50 cm, drainage porosity, content of organic carbon and total nitrogen Parent rocks of these soils were clays, silts and loams of various origin. High content of clay fraction strongly influenced the values of all the analyzed properties. All the examined soils had high content of organic carbon and total nitrogen and reaction close to neutral or alkaline. High content of mineral and organic colloids and, what follows, beneficial state of top horizons’ structure, determined – apart from heavy texture – low soil bulk density and high porosity. The investigated soils were characterized by high field water capacity and wide scopes of total and readily available water. The saturated hydraulic conductivity was low and characteristic to heavy mineral arable soils. The parameter which influenced the variability of analyzed parameters most was texture.

Assessment of heavy metal pollution in drinking water due to mining ...

African Journals Online (AJOL)

Mining and smelting activities are the main causes for the increasing pollution of heavy metals from water sources. The toxicity of these heavy metals from the mining, milling and smelting companies can cause harmful and even lethal effects on the human health. The objective of this study was to investigate the level of As, ...

Health risks associated with heavy metals in the drinking water of Swat, northern Pakistan.

Science.gov (United States)

Lu, Yonglong; Khan, Hizbullah; Zakir, Shahida; Ihsanullah; Khan, Sardar; Khan, Akbar Ali; Wei, Luo; Wang, Tieyu

2013-10-01

The concentrations of heavy metals such as Cd, Cr, Cu, Mn, Ni, Pb and Zn were investigated in drinking water sources (surface and groundwater) collected from Swat valley, Khyber Pakhtunkhwa, Pakistan. The potential health risks of heavy metals to the local population and their possible source apportionment were also studied. Heavy metal concentrations were analysed using atomic absorption spectrometer and compared with permissible limits set by Pakistan Environmental Protection Agency and World Health Organization. The concentrations of Cd, Cr, Ni and Pb were higher than their respective permissible limits, while Cu, Mn and Zn concentrations were observed within their respective limits. Health risk indicators such as chronic daily intake (CDI) and health risk index (HRI) were calculated for adults and children separately. CDIs and HRIs of heavy metals were found in the order of Cr > Mn > Ni > Zn > Cd > Cu > Pb and Cd > Ni > Mn > Cr > Cu > Pb > Zn, respectively. HRIs of selected heavy metals in the drinking water were less than 1, indicating no health risk to the local people. Multivariate and univariate statistical analyses showed that geologic and anthropogenic activities were the possible sources of water contamination with heavy metals in the study area.

Interactions of 10.6 GeV/n gold nuclei with light and heavy target nuclei in nuclear emulsion

International Nuclear Information System (INIS)

Cherry, M.L.; Denes-Jones, P.

1994-03-01

We have investigated the particle production and fragmentation of nuclei participating in the interactions of 10.6 GeV/n gold nuclei in nuclear emulsions. A new criteria has been developed to distinguish between the interactions of these gold nuclei with the light (H, C, N, O) and heavy (Ag, Br) target nuclei in the emulsion. This has allowed separate analyzes of the multiplicity and pseudo-rapidity distributions of the singly charged particles emitted in Au-(H, C, N, O) and Au-(Ag, Br) interactions, as well as of the models of breakup of the projectile and target nuclei. The pseudo-rapidity distributions show strong forward asymmetries, particularly for the interactions with the light nuclei. Heavy target nuclei produce a more severe breakup of the projectile gold nucleus than do the lighter targets. A negative correlation between the number of fragments emitted from the target nuclei and the degree of centrality of the collisions has been observed, which can be attributed to the total destruction of the relatively light target nuclei by these very heavy projectile nuclei. (author). 14 refs, 11 figs, 1 tab

Long term assurance of supply of heavy water

International Nuclear Information System (INIS)

1978-01-01

The answer of Switzerland and Great Britain to a number of questions concerning the long-term assurance of the supply of heavy water are presented. The original problems are seen in the wider context of raw materials supply and its assurance in general. Non-proliferation aspects are touched

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

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)

Benchmark testing of Canadol-2.1 for heavy water reactor

International Nuclear Information System (INIS)

Liu Ping

1999-01-01

The new version evaluated nuclear data library of ENDF-B 6.5 has been released recently. In order to compare the quality of evaluated nuclear data CENDL-2.1 with ENDF-B 6.5, it is necessary to do benchmarks testing for them. In this work, CENDL-2.1 and ENDF-B 6.5 were used to generated the WIMS-69 group library respectively, and benchmarks testing was done for the heavy water reactor, using WIMS5A code. It is obvious that data files of CENDL-2.1 is better than that of old WIMS library for the heavy water reactors calculations, and is in good agreement with those of ENDF-B 6.5

[Heavy metals in environmental media around drinking water conservation area of Shanghai].

Science.gov (United States)

Shi, Gui-Tao; Chen, Zhen-Lou; Zhang, Cui; Bi, Chun-Juan; Cheng, Chen; Teng, Ji-Yan; Shen, Jun; Wang, Dong-Qi; Xu, Shi-Yuan

2008-07-01

The levels of heavy metals in Shanghai drinking water conservation area were determined, and the spatial distributions and main sources of heavy metals were investigated. Moreover, the ecological risk assessment of heavy metals was conducted. Some conclusions can be drawn as follows: (1) The average concentrations of Cd, Hg, Pb, Cu, Zn, Ni, Cr and As in road dust were 0.80, 0.23, 148.45, 127.52, 380.57, 63.17, 250.38 and 10.37 mg x kg(-1) respectively. In terms of the pollution level, the values of soils were relatively lower, with the mean contents of 0.16 (Cd), 0.33 (Hg), 30.14 (Pb), 30.66 (Cu), 103.79 (Zn), 24.04 (Ni), 65.75 (Cr) and 6.31 mg x kg(-1) (As) severally; meanwhile the average levels of heavy metals in vegetables were 0.010 (Cd), 0.016 (Hg), 0.36 (Pb), 12.80 (Cu), 61.69 (Zn), 2.04 (Ni), 2.41 (Cr) and 0.039 mg x kg(-1) (As) respectively. (2) Semivariogram and multivariate analysis indicated that heavy metals pollution of soils was induced by anthropogenic activities mostly, and the pollutants produced by traffic were the major source of heavy metals in road dust. (3) The order for heavy metal enrichment coefficients of vegetables was as following: Zn (0.589) > Cu (0.412) > 0.102 (Ni) > Cd (0.059) > Cr (0.061) > Hg (0.056) > Pb (0.012) > As (0.007), and the results indicated that Cd and Zn in vegetables were mainly from the soils, and the other metals were probably from the pollutants in the atmosphere. (4) Sediments in drinking water conservation area were probably derived from soils around; however, there was no significant relationship between heavy metals contents of them. (5) The results of ecological risk assessment of heavy metals showed that heavy metals in soils were in no-warning to warning situation, and warning to light-warning situation for road dust and vegetables. The fuzzy synthesis judgment for all the environmental media around drinking water conservation area was warning to light-warning.

Growth scenarios with thorium fuel cycles in pressurised heavy water reactors

International Nuclear Information System (INIS)

Balakrishnan, M.R.

1991-01-01

Since India has generous deposits of thorium, the availability of thorium will not be a limiting factor in any growth scenario. It is fairly well accepted that the best system for utilisation of thorium is the heavy water reactor. The growth scenarios possible using thorium in HWRs are considered. The base has been taken as 50,000 tons of natural uranium and practically unlimited thorium. The reference reactor has been assumed to be the PHWR, and all other growth scenarios are compared with the growth scenario provided by the once-through natural cycle in the PHWR. Two reactor types have been considered: the heavy water moderated, heavy water cooled, pressure tube reactor, known as the PHWR; and the heavy water moderated and cooled pressure vessel kind, similar to the ATUCHA reactor in Argentina. For each reactor, a number of different fuel cycles have been studied. All these cycles have been based on thorium. These are: the self-sustaining equilibrium thorium cycle (SSET); the high conversion ratio high burnup cycle; and the once through thorium cycle (OTT). The cycle have been initiated in two ways: one is by starting the cycle with natural uranium, reprocessing the spent fuel to obtain plutonium, and use that plutonium to initiate the thorium cycle; the other is to enrich the uranium to about 2-3% U-235 (the so-called Low Enriched Uranium or LEU), and use the LEU to initiate the thorium cycle. Both cases have been studied, and growth scenarios have been projected for every one of the possible combinations. (author). 1 tab

Heavy metal contamination in stream water and sediments of gold ...

African Journals Online (AJOL)

This study assessed the seasonal variation in heavy metal contamination of stream water and sediments in the gold mining area of Atakunmosa West local Government, Osun State, Nigeria. Twelve villages of prominence in illegal gold mining were selected for the study covering dry and wet seasons of 2012. Stream water ...

The density behaviour of heavy oils in water

International Nuclear Information System (INIS)

Fingas, M.; Hollebone, B.; Fieldhouse, B.

2006-01-01

The recent concern regarding the difficulty of cleaning up Low API gravity oils (LAPIO) spilled in water was discussed. Sinking and overwashing are 2 phenomena related to the behaviour of these heavy oils in water. Sinking refers to the complete submergence of the oil to the bottom of a waterbody, while over-washing refers to the overflowing of a layer of water over dense oil at sea when the oil is still close to the surface. The latter is important because even a micron-layer of water could render the oil undetectable, particularly at acute viewing angles, such as from a ship. This paper reviewed the properties of heavy oil, the prediction of density changes and the sinking/over-washing of heavy oil. In particular, it discussed a spill which occurred in August 2005 when 11 tank cars from train derailment spilled 800,000 litres of Bunker fuel mixed with high PAH-containing pole-treating oil into Lake Wabamun, Alberta. The behaviour of the oil included submergence, neutral buoyancy, resurfacing and formation of several types of aggregates of oil. This study summarized the behaviours and processes that transformed the particles of oil into small tar balls, larger logs, sheets, and large lumps into a slick. Sediment uptake or loss was found to be the major process that caused the changes in density. The behaviour of the oils was compared with respect to density and uptake of various types of sediment. The paper also reviewed the literature on dense oil behaviour. Weathering experiments performed on dense oils to determine if extensive weathering could render oils heavier than water showed that rarely is weathering the only factor in the bulk sinking of oil. Once an oil is submerged, little weathering occurs, either by dissolution or volatilization. The uptake of particulate matter is the most important process in increasing density. This study reviewed over-washing experiments to develop a mathematical solution of the conditions required for oil to be covered by a

Neutron scattering of a floating heavy water bridge

International Nuclear Information System (INIS)

Fuchs, Elmar C; Bitschnau, Brigitte; Woisetschlaeger, Jakob; Maier, Eugen; Beuneu, Brigitte; Teixeira, Jose

2009-01-01

When high voltage is applied to distilled water filled into two beakers close to each other, a water connection forms spontaneously, giving the impression of a floating water bridge (Fuchs et al 2007 J. Phys. D: Appl. Phys. 40 6112-4, 2008 J. Phys. D: Appl. Phys. 41 185502). This phenomenon is of special interest, since it comprises a number of phenomena currently tackled in modern water science. In this work, the first data on neutron scattering of a floating heavy water bridge are presented and possible interpretations are discussed. D 2 O was measured instead of H 2 O because of the very strong incoherent scattering of H. The obtained data support the 'bubble hypothesis' suggested earlier (Fuchs et al 2008).

Removal of Heavy Metals from Drinking Water by Magnetic Carbon Nanostructures Prepared from Biomass

Directory of Open Access Journals (Sweden)

Muhammad Muneeb Ur Rahman Khattak

2017-01-01

Full Text Available Heavy metals contamination of drinking water has significant adverse effects on human health due to their toxic nature. In this study a new adsorbent, magnetic graphitic nanostructures were prepared from watermelon waste. The adsorbent was characterized by different instrumental techniques (surface area analyzer, FTIR, XRD, EDX, SEM, and TG/DTA and was used for the removal of heavy metals (As, Cr, Cu, Pb, and Zn from water. The adsorption parameters were determined for heavy metals adsorption using Freundlich and Langmuir isotherms. The adsorption kinetics and effect of time, pH, and temperature on heavy metal ions were also determined. The best fits were obtained for Freundlich isotherm. The percent adsorption showed a decline at high pH. Best fit was obtained with second-order kinetics model for the kinetics experiments. The values of ΔH° and ΔG° were negative while that of ΔS° was positive. The prepared adsorbent has high adsorption capacities and can be efficiently used for the removal of heavy metals from water.

Studies of the Effect of Heavy Water in the Fast Reactor FR0

Energy Technology Data Exchange (ETDEWEB)

Tiren, L I; Haakansson, R; Karmhag, B

1968-08-15

Core 9 of the FR0 fast critical assembly was diluted with heavy water to 24 vol. per cent, contained in thin walled copper cans. The report describes measurements of the critical mass and the reactivity coefficient of heavy water in this core. The effect of the heterogeneous core composition on these items is also dealt with. The results are compared with theoretical predictions using several computer codes. Criticality is accurately predicted, but the measured reactivity coefficient of heavy water is about 20 % lower than the value obtained with the best available methods, involving the SPENG and DTF-4 programmes. The result of bunching measurements, in which the degree of heterogeneity of core composition was changed, is compared with theoretical estimates of the resonance shielding, flux advantage and leakage components of the heterogeneity effect.

Studies of the Effect of Heavy Water in the Fast Reactor FR0

International Nuclear Information System (INIS)

Tiren, L.I.; Haakansson, R.; Karmhag, B.

1968-08-01

Core 9 of the FR0 fast critical assembly was diluted with heavy water to 24 vol. per cent, contained in thin walled copper cans. The report describes measurements of the critical mass and the reactivity coefficient of heavy water in this core. The effect of the heterogeneous core composition on these items is also dealt with. The results are compared with theoretical predictions using several computer codes. Criticality is accurately predicted, but the measured reactivity coefficient of heavy water is about 20 % lower than the value obtained with the best available methods, involving the SPENG and DTF-4 programmes. The result of bunching measurements, in which the degree of heterogeneity of core composition was changed, is compared with theoretical estimates of the resonance shielding, flux advantage and leakage components of the heterogeneity effect

Chemical elimination of alumina in suspension in nuclear reactors heavy water

International Nuclear Information System (INIS)

Ledoux, A.

1967-02-01

Corrosion of aluminium in contact with moderating water in nuclear reactor leads to the formation of an alumina hydrosol which can have an adverse effect on the operation of the reactor. Several physical methods have been used in an attempt to counteract this effect. The method proposed here consists in the elimination of the aluminium by dissolution and subsequent fixation in the ionic form on mixed-bed ion-exchange resin. In order to do this, the parameters and the values of these parameters most favorable to the dissolution process have been determined. If the moderator is heavy water, the deuterated acid can be prepared by converting a solution in heavy water to a salt of the acid using a deuterated cationic resin. (author) [fr

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

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

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)

Substantial reductions of input energy and peak power requirements in targets for heavy ion fusion

International Nuclear Information System (INIS)

Mark, J.W.K.; Pan, Y.L.

1986-01-01

Two ways of reducing the requirements of the heavy ion driver for inertial confinement fusion (ICF) target implosion are described. Compared to estimates of target gain not using these methods, the target input energy and peak power may be reduced by about a factor of two with the use of the hybrid-implosion concept. Another factor of two reduction in input energy may be obtained with the use of spin-polarized DT fuel in the ICF target

Spectroscopic investigation of the charge dynamics of heavy ions penetrating solid and gaseous targets

International Nuclear Information System (INIS)

Korostiy, S.

2007-01-01

This thesis presents the study of the slowing down process of fast heavy ions inside matter. In the framework of this research, the influence of the target density on the stopping process is investigated. Experiments on the interaction of 48 Ca 6+ - 48 Ca 10+ and 26 Mg 5+ ion beams with initial energies of 11.4 MeV/u and 5.9 MeV/u with solid and gaseous targets have been carried out. A novel diagnostic method, X-ray spectroscopy of K-shell projectile radiation, is used to determine the ion charge state in relation to its velocity during the penetration of fast heavy ions inside the stopping material. A spatially resolved analysis of the projectile and target radiation in solids is achieved for the first time. The application of low-density silica aerogels as stopping media provided a stretching of the ion stopping length by 20 - 100 times in comparison with solid quartz. The Doppler Effect observed on the projectile K-shell spectra is used to calculate the ion velocity in dependence on the ion penetration depth in the target material. A comparative analysis of K α spectra of fast heavy ions is performed in solid (silica aerogels) and gaseous targets (Ar and Ne gases) at the same ion energy. It is shown that the dominant role of collisions in dense matter leads to an increase of the effective ionization cross section at high ion velocity and suppression of the electron capture to the projectile ion excited states at low ion velocity. As a result, an increase of the ion charge state in dense matter is observed. The experimentally detected effects are interpreted with numerical calculations of the projectile population kinetics, which are in good agreement with measurements. (orig.)

Spectroscopic investigation of the charge dynamics of heavy ions penetrating solid and gaseous targets

Energy Technology Data Exchange (ETDEWEB)

Korostiy, S

2007-01-15

This thesis presents the study of the slowing down process of fast heavy ions inside matter. In the framework of this research, the influence of the target density on the stopping process is investigated. Experiments on the interaction of {sup 48}Ca{sup 6+}-{sup 48}Ca{sup 10+} and {sup 26}Mg{sup 5+} ion beams with initial energies of 11.4 MeV/u and 5.9 MeV/u with solid and gaseous targets have been carried out. A novel diagnostic method, X-ray spectroscopy of K-shell projectile radiation, is used to determine the ion charge state in relation to its velocity during the penetration of fast heavy ions inside the stopping material. A spatially resolved analysis of the projectile and target radiation in solids is achieved for the first time. The application of low-density silica aerogels as stopping media provided a stretching of the ion stopping length by 20 - 100 times in comparison with solid quartz. The Doppler Effect observed on the projectile K-shell spectra is used to calculate the ion velocity in dependence on the ion penetration depth in the target material. A comparative analysis of K{sub {alpha}} spectra of fast heavy ions is performed in solid (silica aerogels) and gaseous targets (Ar and Ne gases) at the same ion energy. It is shown that the dominant role of collisions in dense matter leads to an increase of the effective ionization cross section at high ion velocity and suppression of the electron capture to the projectile ion excited states at low ion velocity. As a result, an increase of the ion charge state in dense matter is observed. The experimentally detected effects are interpreted with numerical calculations of the projectile population kinetics, which are in good agreement with measurements. (orig.)

D2O, Computation of Thermodynamic and Transport Properties of Heavy Water

International Nuclear Information System (INIS)

Durmayaz, Ahmet

2000-01-01

1 - Description of program or function: A computer program for the fast computation of the thermodynamic and transport properties of heavy water (D 2 O) at saturation, in subcooled liquid and superheated vapor states. Specific volume (or density), specific enthalpy, specific entropy, constant-pressure specific heat and temperature at saturation are calculated by a number of piecewise continuous approximation functions of (and their derivatives are calculated with respect to) pressure whereas pressure at saturation is calculated by a piecewise continuous approximation function of temperature for heavy water. Density in subcooled liquid state, specific volume in super-heated vapor state, specific enthalpy, specific entropy and constant-pressure specific heat in both of these states are calculated by some piecewise continuous approximation functions of pressure and temperature for heavy water. The correlations used in the calculation of these thermodynamic properties of heavy water were derived by fitting some appropriate curves to the data given in the steam tables by Hill et al (1981). The whole set of correlations and the approximation method used in their derivation are presented by Durmayaz (1997). Dynamic viscosity and thermal conductivity for heavy water are calculated as functions of temperature and density with the correlations given by Hill et al (1981), by Matsunaga and Nagashima (1983) and by Kestin et al (1984). Surface tension for heavy water is calculated as a function of temperature with the correlation given by Crabtree and Siman-Tov (1993). 2 - Methods: A group of pressure-enthalpy (P-h) pairs can be given in an input data file or assigned in the main program without knowing the state in which fluid takes place. In this case, first, the enthalpies at saturation corresponding to the given pressure are computed. Second, the state is determined by comparing the given enthalpy to the saturation enthalpies. Then, the properties are computed. Program D 2 O

Device and method to enrich and process heavy water

International Nuclear Information System (INIS)

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

1979-01-01

A device to process and enrich heavy water is proposed which is based on a combined electrolysis catalyst exchange system in which a D 2 O enrichment of more than 99.8% is achieved in the end stage. Water partly enriched with D 2 -containing hydrogen gas from an electrolysis cell is brought into contact in a catalyst column. The water is further enriched here with deuterium. It is then fed to the electrolysis cell. Details of the apparatus are closely described. (UWI) [de

Benchmark calculations on residue production within the EURISOL DS project; Part II: thick targets

CERN Document Server

David, J.-C; Boudard, A; Doré, D; Leray, S; Rapp, B; Ridikas, D; Thiollière, N

Benchmark calculations on residue production using MCNPX 2.5.0. Calculations were compared to mass-distribution data for 5 different elements measured at ISOLDE, and to specific activities of 28 radionuclides in different places along the thick target measured in Dubna.

Implementation of TTIK method and time of flight for resonance reaction studies at heavy ion accelerator DC-60

Energy Technology Data Exchange (ETDEWEB)

Nurmukhanbetova, A.K. [National Laboratory Astana, Nazarbayev University, Astana 010000 (Kazakhstan); Goldberg, V.Z. [Cyclotron Institute, Texas A& M University, College Station, TX (United States); Nauruzbayev, D.K. [National Laboratory Astana, Nazarbayev University, Astana 010000 (Kazakhstan); Saint Petersburg State University, Saint Petersburg (Russian Federation); Rogachev, G.V. [Cyclotron Institute, Texas A& M University, College Station, TX (United States); Golovkov, M.S. [Joint Institute of Nuclear Research, Dubna (Russian Federation); Dubna State University, Dubna (Russian Federation); Mynbayev, N.A. [National Laboratory Astana, Nazarbayev University, Astana 010000 (Kazakhstan); Artemov, S.; Karakhodjaev, A. [Institute of Nuclear Physics, Tashkent (Uzbekistan); Kuterbekov, K. [L.N. Gumilov Eurasian National University, Astana (Kazakhstan); Rakhymzhanov, A. [National Laboratory Astana, Nazarbayev University, Astana 010000 (Kazakhstan); Berdibek, Zh. [School of Science and Technology, Nazarbayev University, Astana (Kazakhstan); Ivanov, I. [Institute of Nuclear Physics, Astana (Kazakhstan); Tikhonov, A. [School of Science and Technology, Nazarbayev University, Astana (Kazakhstan); Zherebchevsky, V.I.; Torilov, S. Yu. [Saint Petersburg State University, Saint Petersburg (Russian Federation); Tribble, R.E. [Cyclotron Institute, Texas A& M University, College Station, TX (United States)

2017-03-01

To study resonance reactions of heavy ions at low energy we have combined the Thick Target Inverse Kinematics Method (TTIK) with Time of Flight method (TF). We used extended target and TF to resolve the identification problems of various possible nuclear processes inherent to the simplest popular version of TTIK. Investigations of the {sup 15}N interaction with hydrogen and helium gas targets by using this new approach are presented.

Elastic wave from fast heavy ion irradiation on solids

CERN Document Server

Kambara, T; Kanai, Y; Kojima, T M; Nanai, Y; Yoneda, A; Yamazaki, Y

2002-01-01

To study the time-dependent mechanical effects of fast heavy ion irradiations, we have irradiated various solids by a short-bunch beam of 95 MeV/u Ar ions and observed elastic waves generated in the bulk. The irradiated targets were square-shaped plates of poly-crystals of metals (Al and Cu), invar alloy, ceramic (Al sub 2 O sub 3), fused silica (SiO sub 2) and single crystals of KC1 and LiF with a thickness of 10 mm. The beam was incident perpendicular to the surface and all ions were stopped in the target. Two piezo-electric ultrasonic sensors were attached to the surface of the target and detected the elastic waves. The elastic waveforms as well as the time structure and intensity of the beam bunch were recorded for each shot of a beam bunch. The sensor placed opposite to the beam spot recorded a clear waveform of the longitudinal wave across the material, except for the invar and fused silica targets. From its propagation time along with the sound velocity and the thickness of the target, the depth of the...

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

Study of Target Fragmentation in the Interaction of 86 MeV/A $^{12}$Carbon with Tantalum, Bismuth and Uranium

CERN Multimedia

2002-01-01

Using radiochemical techniques we will ; a)~~measure the target fragment mass and charge distributions from the interaction of 86~MeV/A |1|2C with Ta, Bi and U; ; b)~~measure the target fragment forward momentum and average kinetic energy using the thick target-thick catcher technique for the above reactions; and ; c)~~measure the target fragment angular and differential energy distributions using thin target-thin catcher techniques for the reactions with Ta and U. \\\\ \\\\ These measurements should allow us to better characterize the transition between low energy and realistic heavy ion reaction mechanisms.

Reactivity effect of a heavy water tank as reflector in the IPEN/MB-01 reactor

International Nuclear Information System (INIS)

Santos, Adimir dos; Fuga, Rinaldo

2013-01-01

This experiment comprises a set of experiments performed in the IPEN/MB-01 reactor and described in the International Handbook of Evaluated Reactor Physics Benchmark Experiments, specifically the experiment aim to evaluate the reactivity due to the heavy water tank placed at reflector region of the IPEN/MB-01 reactor. An aluminum tank was designed to be filled with heavy water and positioned at the west face of the IPEN/MB-01, additionally the experiment was also designed to allow variable heavy water height inside of this tank providing different neutron leakage rate in the west face of the IPEN/MB-01, consequently providing a series of interesting combinations. The measured quantities in the experiment are reactivities and critical control bank positions for several combinations of the control banks and an excess of reactivity of the heavy water tank. The experiment will be simulated using a Monte Carlo code MCNP in order to compare the different critical control bank position. (author)

Energy straggling determination for charged particles in thick targets

International Nuclear Information System (INIS)

Lopez M, J.

1980-01-01

Energy straggling is reported for deuterons in carbon and protons in silicon, and the data obtained is compared with predictions of Bohr and Bethe. The experimental method used is based on a reaction resonance widening, observed at backward angles in the thick targets. The incident energy determines the depth at which the resonant scattering occurs and the energy straggling can be measured from the backscattering spectra. The data obtained for the energy straggling of deuterons are approximately two times bigger than those predicted by Bohr's theory; nevertheless, the values found for the energy straggling of protons in silicon are in agreement with the values predicted by the aforesaid theory. This disagreement was explained by the fact that carbon targets used were amorphous and porous, in contrast with those of cristal silicon, (it is an experimental fact that porous materials are expected to give higher stragglings than non-porous ones). Thus, the method reviewed in this work is valid, but the porosity effects should be taken into account in comparing results among materials with different densities. (author)

Advances in heavy water reactors

International Nuclear Information System (INIS)

1994-03-01

The current IAEA programme in advanced nuclear power technology promotes technical information exchange between Member States with major development programmes. The Technical Committee Meeting (TCM) on Advances in Heavy Water Reactors was organized by the IAEA in the framework of the activities of the International Working Group on Advanced Technologies for Water Cooled Reactors (IWGATWR) and hosted by the Atomic Energy of Canada Limited. Sixty-five participants from nine countries (Canada, Czech Republic, India, German, Japan, Republic of Korea, Pakistan, Romania and USA) and the IAEA attended the TCM. Thirty-four papers were presented and discussed in five sessions. A separate abstract was prepared for each of these papers. All recommendations which were addressed by the participants of the Technical Committee meeting to the IWGATWR have been submitted to the 5th IWGATWR meeting in September 1993. They were reviewed and used as input for the preparation of the IAEA programme in the area of advanced water cooled reactors. This TCM was mainly oriented towards advances in HWRs and on projects which are now in the design process and under discussion. Refs, figs and tabs

Poultry litter-based activated carbon for removing heavy metal ions in water.

Science.gov (United States)

Guo, Mingxin; Qiu, Guannan; Song, Weiping

2010-02-01

Utilization of poultry litter as a precursor material to manufacture activated carbon for treating heavy metal-contaminated water is a value-added strategy for recycling the organic waste. Batch adsorption experiments were conducted to investigate kinetics, isotherms, and capacity of poultry litter-based activated carbon for removing heavy metal ions in water. It was revealed that poultry litter-based activated carbon possessed significantly higher adsorption affinity and capacity for heavy metals than commercial activated carbons derived from bituminous coal and coconut shell. Adsorption of metal ions onto poultry litter-based carbon was rapid and followed Sigmoidal Chapman patterns as a function of contact time. Adsorption isotherms could be described by different models such as Langmuir and Freundlich equations, depending on the metal species and the coexistence of other metal ions. Potentially 404 mmol of Cu2+, 945 mmol of Pb2+, 236 mmol of Zn2+, and 250-300 mmol of Cd2+ would be adsorbed per kg of poultry litter-derived activated carbon. Releases of nutrients and metal ions from litter-derived carbon did not pose secondary water contamination risks. The study suggests that poultry litter can be utilized as a precursor material for economically manufacturing granular activated carbon that is to be used in wastewater treatment for removing heavy metals.

Impact of different moderator ratios with light and heavy water cooled reactors in equilibrium states

International Nuclear Information System (INIS)

Permana, Sidik; Takaki, Naoyuki; Sekimoto, Hiroshi

2006-01-01

As an issue of sustainable development in the world, energy sustainability using nuclear energy may be possible using several different ways such as increasing breeding capability of the reactors and optimizing the fuel utilization using spent fuel after reprocessing as well as exploring additional nuclear resources from sea water. In this present study the characteristics of light and heavy water cooled reactors for different moderator ratios in equilibrium states have been investigated. The moderator to fuel ratio (MFR) is varied from 0.1 to 4.0. Four fuel cycle schemes are evaluated in order to investigate the effect of heavy metal (HM) recycling. A calculation method for determining the required uranium enrichment for criticality of the systems has been developed by coupling the equilibrium fuel cycle burn-up calculation and cell calculation of SRAC 2000 code using nuclear data library from the JENDL 3.2. The results show a thermal spectrum peak appears for light water coolant and no thermal peak for heavy water coolant along the MFR (0.1 ≤ MFR ≤ 4.0). The plutonium quality can be reduced effectively by increasing the MFR and number of recycled HM. Considering the effect of increasing number of recycled HM; it is also effective to reduce the uranium utilization and to increase the conversion ratio. trans-Plutonium production such as americium (Am) and curium (Cm) productions are smaller for heavy water coolant than light water coolant. The light water coolant shows the feasibility of breeding when HM is recycled with reducing the MFR. Wider feasible area of breeding has been obtained when light water coolant is replaced by heavy water coolant

Heavy metal contamination of water and fish in peri-urban dams ...

African Journals Online (AJOL)

Heavy metals were measured in water, sediment and fish in dams located downstream of effluent discharge zones in Bulawayo and were compared to those in a pristine upstream dam. Water conductivity indicated pollution of downstream dams. Levels of lead (0.13 – 0.28 ppm) and cadmium (0.02 – 0.06 ppm) in water from ...

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

Heavy metal pollution in drinking water - a global risk for the human ...

African Journals Online (AJOL)

Fabian Fernandez

parts of the world heavy metal (HM) concentrations in drinking water are higher than some international guideline values. ..... become the basis for several drinking water treatment approaches ...... physiological and hygienic needs. Monitoring ...

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)

Water Quality and Heavy Metal Concentrations in Sediment of Sungai Kelantan, Kelantan, Malaysia: A Baseline Study

International Nuclear Information System (INIS)

Ahmad, A.K.; Mushrifah, I.; Mohamad Shuhaimi Othman

2009-01-01

A study on water quality and heavy metal concentration in sediment at selected sites of Sungai Kelantan was carried out. Ten water samples were collected along the river for physical and chemical analysis and twenty-six water and sediment samples were collected for heavy metal analysis. Water was sampled at three different dates throughout the study period whereas sediments were collected once. In addition to heavy metal analysis, sediment samples were also analysed for texture, ph and organic content. The physical and chemical water quality analyses were carried out according to the ALPHA procedures. Result of water quality analysis (physico-chemical) indicated that Sungai Kelantan is characterised by excellent water quality and comparable to pristine ecosystems such as the National Park and Kenyir Lake. This river was classified into class I - class III based on Malaysian interim water quality standard criteria (INWQS). Heavy metals Pb, Zn, Cu and Cd was detected at low concentration in sediment samples, except for Fe and Mn. The presence of Fe and Mn in sediment samples was though to be of natural origin from the soil. Anthropogenic metal concentrations in sediment were low indicating that Sungai Kelantan has not experienced extreme pollution. (author)

The heavy ion fusion program in the USA

International Nuclear Information System (INIS)

Bangerter, R.O.; Davidson, R.C.; Herrmannsfeldt, W.B.; Lindl, J.; Meier, W.R.; Logan, B.G.

2001-01-01

Inertial fusion energy research has enjoyed increased interest and funding. This has allowed expanded programs in target design, target fabrication, fusion chamber research, target injection and tracking, and accelerator research. The target design effort examines ways to minimize the beam power and energy and increase the allowable focal spot size while preserving target gain. Chamber research for heavy ion fusion emphasizes the use of thick liquid walls to serve as the coolant, breed tritium, and protect the structural wall from neutrons, photons, and other target products. Several small facilities are now operating to model fluid chamber dynamics. A facility to study target injection and tracking has been built and a second facility is being designed. Improved economics is an important goal of the accelerator research. The accelerator research is also directed toward the design of an Integrated Research Experiment (IRE). The IRE is being designed to accelerate ions to >100 MeV, enabling experiments in beam dynamics, focusing, and target physics. Activities leading to the IRE include ion source development and a High Current Experiment (HCX) designed to transport and accelerate a single beam of ions with a beam current of approximately 1 A, the initial current required for each beam of a fusion driver. In terms of theory, the program is developing a source-to-target numerical simulation capability. The goal of the entire program is to enable an informed decision about the promise of heavy ion fusion in about a decade. (author)

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.

Process development, design and operation of off-line purification system for oil-contaminated impure heavy water

International Nuclear Information System (INIS)

Bose, H.; Rakesh Kumar; Gandhi, H.C.; Unny, V.K.P.; Ghosh, S.K.; Mishra, Vivek; Shukla, D.K.; Duraisamy, S.; Agarwal, S.K.

2004-01-01

A large volume of degraded, tritiated heavy water contaminated with mineral oil and ionic impurities have accumulated at Dhruva in the past years of reactor operation as a result of routine operation and maintenance activities. The need was felt for a simple and efficient process that could be set up and operated locally at site using readily available materials, to purify the accumulated impure heavy waters at Dhruva so as to make them acceptable at the up gradation facilities. After a detailed laboratory study, a three stage clean-up process was developed which could purify a highly turbid oil-water emulsion to yield clear, oil-free and de-mineralized heavy water at reasonable rates of volume through-put. Based on the laboratory data, a suitably scaled up purification unit has been designed and commissioned which in the past few months has processed a sizeable volume of oil-contaminated heavy water waste from Dhruva, with most satisfactory results

Investigations for heavy metals pollution in the Nile water in Khartoum area using XRF

International Nuclear Information System (INIS)

Salih, Saadia Elsir

1998-06-01

The purpose of this study was to perform measurements for heavy metals pollution in the Nile water in Khartoum area. Ten locations were selected for the study on the white Nile, the Blue Nile and the Nile. Standard methods were used for samples collection and preparation for the measurements using XRF. Nine elements were observed and their concentrations determined in the various locations. These Ti, Cr, Fe, Cu, Zn, As, Pb, Zr, and Se. From the performed measurements for heavy metals pollution in the Nile water in Khartoum area using the XRF method the following conclusions can be made: There is no heavy metal pollution in the Nile water in Khartoum area resulting from industrial activities. However, there are indications for possible Pb pollution resulting from automobile emission. - The concentrations for the observed heavy metals, except Fe, were much below the maximum permissible international levels provided by the USA, EEC and WHO. - The origin for the observed concentrations of heavy metals, except for Pb, was considered to be soil and silt carried by river in it's journey from the Ethiopian Highlands and lake Victoria. (Author)

A study of pollution extent in some drinking water resources by heavy elements in Hadramout governorate

International Nuclear Information System (INIS)

Barheyan, Saad Awadh

2001-01-01

The paper is considered as a preliminary study of pollution extent in some drinking water resources in Hadramout governorate by heavy elements which differ in their toxicity. The elements subjected to study are Cd, Pb, Fe, Cr, Mn, Zn, Co and Cu. Atomic absorption spectrometric method of analysis (AAS) is used for the determination of heavy elements concentrations. The elemental analysis of drinking water samples shows that the concentration of the above-mentioned elements in drinking water resources, lies in the permissible limit given by the WHO. Similarity of elements content is observed in Thela and Fuwah waters, bu the case is different for Ghail Bawzeer and Asshihir waters due to their different lithospheric structures. Drinking water used by the civilians is not subjected to physical, biological or chemical treatment which may lead to total or partial removal of heavy elements and other rejected impurities. Drinking water running in distribution nets is a hard water and has a weak base (Ph which explains the reason why heavy elements are absorbed and precipitated inside drinking water pipes before they reach consumers. This type of hard water causes accumulation of salt precipitates inside the water pipes which results in many economic and health disturbances to consumers. The slight increase of Cr, Mn, and Co concentration in drinking water flowing in the pipes may be due to the effect of some anions such as nitrates which form soluble compounds with the elements contained in the chemical composition of the drinking water pipes. This paper is a strong indicator for determination of heavy elements concentrations in different drinking water resources in Hadramout govemorate. Such approach seeks a further comprehensive work with special focus on the study of lithospheric structure of the feeding water regions of Hadramout aquifers. (author)

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

Nanometer-resolution electron microscopy through micrometers-thick water layers

Energy Technology Data Exchange (ETDEWEB)

Jonge, Niels de, E-mail: niels.de.jonge@vanderbilt.edu [Vanderbilt University Medical Center, Department of Molecular Physiology and Biophysics, Nashville, TN 37232-0615 (United States); Oak Ridge National Laboratory, Materials Science and Technology Division, Oak Ridge, TN 37831-6064 (United States); Poirier-Demers, Nicolas; Demers, Hendrix [Universite de Sherbrooke, Electrical and Computer Engineering, Sherbrooke, Quebec J1K 2R1 (Canada); Peckys, Diana B. [Oak Ridge National Laboratory, Materials Science and Technology Division, Oak Ridge, TN 37831-6064 (United States); University of Tennessee, Center for Environmental Biotechnology, Knoxville, TN 37996-1605 (United States); Drouin, Dominique [Universite de Sherbrooke, Electrical and Computer Engineering, Sherbrooke, Quebec J1K 2R1 (Canada)

2010-08-15

Scanning transmission electron microscopy (STEM) was used to image gold nanoparticles on top of and below saline water layers of several micrometers thickness. The smallest gold nanoparticles studied had diameters of 1.4 nm and were visible for a liquid thickness of up to 3.3 {mu}m. The imaging of gold nanoparticles below several micrometers of liquid was limited by broadening of the electron probe caused by scattering of the electron beam in the liquid. The experimental data corresponded to analytical models of the resolution and of the electron probe broadening as function of the liquid thickness. The results were also compared with Monte Carlo simulations of the STEM imaging on modeled specimens of similar geometry and composition as used for the experiments. Applications of STEM imaging in liquid can be found in cell biology, e.g., to study tagged proteins in whole eukaryotic cells in liquid and in materials science to study the interaction of solid:liquid interfaces at the nanoscale.

Bioaccumulation of heavy metals in organs of fresh water fish Cyprinus carpio (Common carp)

International Nuclear Information System (INIS)

Vinodhini, R.; Narayanan, M.

2008-01-01

The objective of the present study is to determine the bioaccumulation of heavy metals in various organs of the fresh water fish exposed to heavy metal contaminated water system. The experimental fish was exposed to Cr. Ni, Cd and Pb at sublethal concentrations for periods of 32 days. The elements Cd, Pb, Ni and Cr were assayed using Shimadzu AA 6200 atomic absorption spectrophotometry and the results were given as μg/g dry wt. The accumulation of heavy metal gradually increases in liver during the heavy metal exposure period. All the results were statistically significant at p Pb > Ni > Cr and Pb > Cd > Ni > Cr. Similarly, in case of kidney and flesh tissues, the order was Pb > Cd > Cr > Ni and Pb > Cr > Cd > Ni. In all heavy metals, the bioaccumulation of lead and cadmium proportion was significantly increased in the tissues of Cyprinus carpio (Common carp)

Measurement of M{sup 3} and k{sub {infinity}} for heavy water natural uranium assembly

Energy Technology Data Exchange (ETDEWEB)

Popovic, D; Raisic, N; Markovic, H; Takac, S; Zdravkovic, Z; Lolic, B [Boris Kidric Institute of Nuclear Sciences, Vinca, Beograd (Yugoslavia)

1959-03-15

The migration length M and the infinite multiplication factor k{sub {infinity}} of the heavy water-natural uranium bare assembly are determined by measuring the reactivity of the reactor as function of the heavy water level. Since the assembly is non reflected the results obtained are of relatively high accuracy. (author)

An Induction Linac Driver For A 0.44 MJ Heavy-Ion Direct Drive Target

International Nuclear Information System (INIS)

Seidl, P.A.; Lee, E.P.; Bangerter, R.O.; Faltens, A.

2010-01-01

The conceptual design of a heavy ion fusion driver system is described, including all major components. Particular issues emerging from this exercise are identified and discussed. The most important conclusion of our study is that due to stringent requirements on ion pulse phase space, we are unable to find a credible accelerator design that meets the requirements of the example target. Either the target design must be modified to accept larger ion ranges and larger focal spot sizes, or we must consider other target options.

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

Parametric study of postulated reactivity transients due to ingress of heavy water from the reflector tank into the converted core of APSARA reactor

International Nuclear Information System (INIS)

Sankaranarayanan, S.

2004-01-01

Research reactors in the power range 5-10 MW with useable neutron flux values >1.OE+14 n/sqcm/sec can be constructed using LEU fuel with light water for neutron moderation and fuel cooling. In order to obtain a large irradiation volume, a heavy water reflector is used where fairly high neutron flux levels can be obtained. A prototype LEU fuelled 5/10 MW reactor design has been developed in the Bhabha Atomic Research Centre in Trombay. Work is on hand to carry out technology simulation of this reactor design by converting the pool type reactor APSARA in BARC. Presently the Apsara reactor uses MTh type high enriched U-Al alloy plate type fuel loaded in a 7x7 grid with a square lattice pitch of 76.8 mm. The reactor has three control-scram-shut off rods and one regulating control rod. In the first phase of the simulation studies, it is proposed to use the existing high enriched uranium fuel in a modified core with 37 positions arranged with a square lattice pitch of 84.8 mm, surrounded by a 50 cm thick heavy water reflector. Subsequently the converted core will use plate-type low enriched uranium suicide fuel. One of the accident scenarios postulated for the safety evaluation of the modified APSARA reactor is the reactivity transient due to the ingress of heavy water into the core through a small sized rupture in the aluminium wall of the reflector tank. Parametric analyses were done for the safety evaluation of modified Apsara reactor, for postulated leak of heavy water into the core from the reflector tank. A simplified computer code REDYN, based on point model reactor kinetics with one effective group of delayed neutrons is used for the analyses. Results of several parametric cases used in the study show that it is possible to contain the consequences of this type of reactivity transient within acceptable fuel and coolant thermal safety limits

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.

Thickness and structure of the water film deposited from vapour on calcite surfaces

DEFF Research Database (Denmark)

Bohr, Jakob; Wogelius, Roy A.; Morris, Peter M.

2010-01-01

Synchrotron X-ray reflectivity (SXR) was used to measure the thickness of the water film that adsorbs on a {10¯14} cleavage surface of calcite (CaCO3) in a sample chamber where relative humidity could be controlled within the range from......Synchrotron X-ray reflectivity (SXR) was used to measure the thickness of the water film that adsorbs on a {10¯14} cleavage surface of calcite (CaCO3) in a sample chamber where relative humidity could be controlled within the range from...

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.

Review of high excitation energy structures in heavy ion collisions: target excitations and three body processes

International Nuclear Information System (INIS)

Frascaria, N.

1987-09-01

A review of experimental results on high excitation energy structures in heavy ion inelastic scattering is presented. The contribution to the spectra of the pick-up break-up mechanism is discussed in the light of the data obtained with light heavy ion projectiles. Recent results obtained with 40 Ar beams at various energies will show that target excitations contribute strongly to the measured cross section

Determination of heavy metals and genotoxicity of water from an ...

African Journals Online (AJOL)

Determination of heavy metals and genotoxicity of water from an artesian well ... do Amaral, Vanessa Marques de Oliveira Moraes, Luciana Pereira Silva ... environmental interest because it is the most important zinc producer district of Brazil.

Confined methane-water interfacial layers and thickness measurements using in situ Raman spectroscopy.

Science.gov (United States)

Pinho, Bruno; Liu, Yukun; Rizkin, Benjamin; Hartman, Ryan L

2017-11-07

Gas-liquid interfaces broadly impact our planet, yet confined interfaces behave differently than unconfined ones. We report the role of tangential fluid motion in confined methane-water interfaces. The interfaces are created using microfluidics and investigated by in situ 1D, 2D and 3D Raman spectroscopy. The apparent CH 4 and H 2 O concentrations are reported for Reynolds numbers (Re), ranging from 0.17 to 8.55. Remarkably, the interfaces are comprised of distinct layers of thicknesses varying from 23 to 57 μm. We found that rarefaction, mixture, thin film, and shockwave layers together form the interfaces. The results indicate that the mixture layer thickness (δ) increases with Re (δ ∝ Re), and traditional transport theory for unconfined interfaces does not explain the confined interfaces. A comparison of our results with thin film theory of air-water interfaces (from mass transfer experiments in capillary microfluidics) supports that the hydrophobicity of CH 4 could decrease the strength of water-water interactions, resulting in larger interfacial thicknesses. Our findings help explain molecular transport in confined gas-liquid interfaces, which are common in a broad range of societal applications.

Spectroscopy of very heavy nuclei with a view to study super-heavy nuclei

International Nuclear Information System (INIS)

Khalfallah, F.

2007-08-01

Within the recent years, the spectroscopic study of single particle orbitals of very heavy elements (VHE) has become possible with the development of increasingly efficient experimental setups. This allows us, through nuclear deformation, to access with these deformed nuclei to orbitals situated around the Fermi level in the spherical superheavy elements (SHE) and learn more about the nuclear structure of these nuclei. The aim of this work is the spectroscopic studies of heavy and very heavy elements. Because of the experimental difficulties associated with the fusion reactions in the VHE region, a detailed optimization studies is essential. Simulation of energy loss and angular straggling of these nuclei due to the interaction in the target and to neutron's evaporation was carried out and allowed us to optimize the angular acceptance of the separators according to the target thickness. An extensive survey and exploration in the VHE region was also conducted on the basis of cross section's systematics in the literature and simulations carried out using the statistical code Hivap. In this framework, the possible extension of the range of validity of a set of Hivap parameters was investigated. This work has enabled us to prepare a list of experiments of interest for the production of very heavy nuclei. In this thesis, our work was concentrated on the spectroscopy of the nuclei No 256 et Rf 256 for which two experimental proposals were accepted. The octupole deformations predicted in the actinides region is studied in another part of this thesis, a part witch is dedicated to the gamma spectroscopy of Pa 223 . The data from a new experiment carried out using the Jurogam-Ritu-Great setup are analysed and compared to previous results. They confirm the octupole deformed shape in this nucleus. (author)

Monitoring of heavy metals in selected Water Supply Systems in Poland, in relation to current regulations

Science.gov (United States)

Szuster-Janiaczyk, Agnieszka; Zeuschner, Piotr; Noga, Paweł; Skrzypczak, Marta

2018-02-01

The study presents an analysis of water quality monitoring in terms of the content of heavy metals, which is conducted in three independent water supply systems in Poland. The analysis showed that the monitoring of heavy metals isn't reliable - both the quantity of tested water samples and the location of the monitoring points are the problem. The analysis of changes in water quality from raw water to tap water was possible only for one of the analysed systems and indicate a gradual deterioration of water quality, although still within acceptable limits of legal regulations.

Water hammer with fluid-structure interaction in thick-walled pipes

NARCIS (Netherlands)

Tijsseling, A.S.

2007-01-01

A one-dimensional mathematical model is presented which describes the acoustic behaviour of thick-walled liquid-filled pipes. The model is based on conventional water-hammer and beam theories. Fluid–structure interaction (FSI) is taken into account. The equations governing straight pipes are derived

Selective heavy metals removal from waters by amorphous zirconium phosphate: behavior and mechanism.

Science.gov (United States)

Pan, Bingcai; Zhang, Qingrui; Du, Wei; Zhang, Weiming; Pan, Bingjun; Zhang, Qingjian; Xu, Zhengwen; Zhang, Quanxing

2007-07-01

Selective removal of heavy metals from water has been of considerable concern for several decades. In the present study, the amorphous zirconium phosphate (ZrP) was synthesized and characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron micrography (SEM), thermogravimetric analysis (TGA) as well as pH-titration experiments. Uptake of heavy metals including lead, cadmium, and zinc onto ZrP was studied by using a polystyrene sulfonic-acid exchanger D-001 as a reference sorbent and Ca(2+) as a competing cation due to its ubiquity in natural or industrial waters. The results indicated that the uptake of heavy metals onto ZrP is essentially an ion-exchange process and dependent upon solution pH. In comparison with D-001, ZrP exhibited more favorable sorption of heavy metals particularly in terms of high selectivity, as indicated by the distribution coefficients of ZrP even several orders higher than D-001 towards heavy metals when calcium ion coexisted at a high level in solution. The Fourier transform-infrared (FT-IR) spectroscopic investigation indicated that the uptake of calcium, cadmium, and zinc ions onto ZrP is only driven by the electrostatic interaction, while that of lead ion is possibly dependent upon the inner-sphere complex formation with ZrP. XPS results further elucidated that ZrP displays different sorption affinity towards heavy metals in the same order as selectivity sequence of Pb(2+)>Zn(2+) approximately Cd(2+)>Ca(2+), which can be explained by hard and soft acids and bases (HASB) theory. Moreover, uptake of heavy metals onto ZrP approached to equilibrium quickly and the used ZrP could be readily regenerated for reuse by the dilute HCl solution. Thus, all the results suggest that amorphous ZrP has excellent potential as a sorption material for water treatment.

Combined electrolysis and catalytic exchange (CECE) technology - an economical alternative for heavy water upgraders using water distillation

International Nuclear Information System (INIS)

Ryland, D.K.; Sadhankar, R.R.

2003-01-01

Heavy water upgrading is a unique and crucial part of a CANDU power station. Water distillation (DW) systems are used for heavy water upgrading in all CANDU stations. The DW upgrader is designed to take advantage of the difference in relative volatility (a measure of separation of isotopes) between H 2 O and D 2 O. However, the low relative volatility of the H 2 O/D 2 O system requires large number of stages (long columns) and large reflux ratios (large reboiler loads) - thus resulting in significant capital and operating costs. Atomic Energy of Canada Limited (AECL) developed the Combined Electrolysis and Catalytic Exchange (CECE) technology as an economical alternative to the DW system. CECE-based upgraders have been demonstrated in pilot scale facilities at AECL Chalk River Laboratories and in Hamilton, Ontario. This design is based on catalytic hydrogen isotope exchange between water and hydrogen gas. (author)

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)

A real-time tritium-in-water monitor for measurement of heavy water leak to the secondary coolant

International Nuclear Information System (INIS)

Rathnakaran, M.; Ravetkar, R.M.; Samant, R.K.; Abani, M.C.

2000-01-01

The paper describes the development and evaluation of on-line, real-time tritium in water monitor for detection and measurement of heavy water leak to the secondary coolant in a Pressurised Heavy Water Reactor. The detector used for this is a plastic scintillator film, made in the form of sponge and housed in a flow cell which is used for measurement of tritium activity present in heavy water. Two photomultiplier tubes are optically coupled on either face of the flow cell detector and measurement is done in coincidence mode. The sample water is continuously passed through the flow cell detector and a continuous measurement of tritium activity is carried out. It is observed that the impurities in the process water sample are gradually trapped in the flow cell, which affects the transparency of the detector with use. This reduces the sensitivity of the system. In addition, chlorine, which is added in the sample water, to arrest the fungus formation, creates chemiluminescence which interfere the measurement. To improve the sample quality as well as to eliminate the chemiluminescence created by chlorine, sample conditioner consisting of polypropylene candle, activated charcoal and glass fibre filter paper is developed. Polypropylene candle traps particulates above 5 μm pore size, activated charcoal absorbs organic compounds, free chlorine, fungus and turbidity and glass fibre filter paper stops submicron size particles. The measurement is also affected by the interference of dissolved argon-41 in the sample water. A bubbler system developed at BARC is used to strip the dissolved Ar-41 present in the sample which enables the system to measure tritium in presence of this interfering radioactive gas. The microprocessor based electronic system, used in the monitor provides the facility for selection of counting time and thereby improving the counting statistics. Alarm circuit is provided to give timely alarm when the tritium activity concentration exceeds the preset level

Assessment of natural radioactivity and heavy metals in water and soil around seismically active area

International Nuclear Information System (INIS)

Oktay Baykara; Mahmut Dogru; Firat University, Elazig

2010-01-01

The natural radioactivity concentration and some heavy metals in various water and soil samples collected from seismically active area have been determined. Gross-alpha and beta concentrations of different 33 water samples and some heavy metal (Fe, Pb, Cu, K, Mn, Cr and Zn) concentration in 72 soil samples collected from two major fault systems (North and East Anatolian Active Fault Systems) in Turkey have been studied. This survey regarding gross-alpha and beta radioactivity and some heavy metals concentrations was carried out by means of Krieger method using a gross-alpha and beta-counting system and atomic absorption spectrometry (AAS), respectively. Also, gross annual effective dose from the average gross-alpha activity in waters were calculated. (author)

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.)

Geothermal and heavy-oil resources in Texas

Energy Technology Data Exchange (ETDEWEB)

Seni, S.J.; Walter, T.G.

1994-01-01

In a five-county area of South Texas, geopressured-geothermal reservoirs in the Paleocene-Eocene Wilcox Group lie below medium- to heavy-oil reservoirs in the Eocene Jackson Group. This fortuitous association suggests the use of geothermal fluids for thermally enhanced oil recovery (TEOR). Geothermal fairways are formed where thick deltaic sandstones are compartmentalized by growth faults. Wilcox geothermal reservoirs in South Texas are present at depths of 11,000 to 15,000 ft (3,350 to 4,570 m) in laterally continuous sandstones 100 to 200 ft (30 to 60 m) thick. Permeability is generally low (typically 1 md), porosity ranges from 12 to 24 percent, and temperature exceeds 250{degrees}F (121{degrees}C). Reservoirs containing medium (20{degrees} to 25{degrees} API gravity) to heavy (10{degrees} to 20{degrees} API gravity) oil are concentrated along the Texas Coastal Plain in the Jackson-Yegua Barrier/Strandplain (Mirando Trend), Cap Rock, and Piercement Salt Dome plays and in the East Texas Basin in Woodbine Fluvial/Deltaic Strandplain and Paluxy Fault Line plays. Injection of hot, moderately fresh to saline brines will improve oil recovery by lowering viscosity and decreasing residual oil saturation. Smectite clay matrix could swell and clog pore throats if injected waters have low salinity. The high temperature of injected fluids will collapse some of the interlayer clays, thus increasing porosity and permeability. Reservoir heterogeneity resulting from facies variation and diagenesis must be considered when siting production and injection wells within the heavy-oil reservoir. The ability of abandoned gas wells to produce sufficient volumes of hot water over the long term will also affect the economics of TEOR.

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

Transmutation of Americium in Light and Heavy Water Reactors

Energy Technology Data Exchange (ETDEWEB)

Hyland, B.; Dyck, G.R.; Edwards, G.W.R. [Chalk River Laboratories, Atomic Energy of Canada Limited (Canada); Ellis, R.J.; Gehin, J.C. [Oak Ridge National Laboratory (ORNL), Oak Ridge, Tennessee (United States); Maldonado, G.I. [University of Tennessee (Knoxville)/ORNL, Tennessee (United States)

2009-06-15

There is interest worldwide in reducing the burden on geological nuclear fuel disposal sites. In most disposal scenarios the decay heat loading of the surrounding rock limits the capacity of these sites. On the long term, this decay heat is generated primarily by actinides, and a major contributor 100 to 1000 years after discharge from the reactor is {sup 241}Am. One possible approach to reducing the decay-heat burden is to reprocess spent reactor fuel and use thermal spectrum reactors to 'burn' the Am nuclides. The viability of this approach is dependent upon the detailed changes in chemical and isotopic composition of actinide-bearing fuels after irradiation in thermal reactor spectra. The currently available thermal spectrum reactor options include light water-reactors (LWRs) and heavy-water reactors (HWRs) such as the CANDU{sup R} designs. In addition, as a result of the recycle of spent LWR fuel, there would be a considerable amount of potential recycled uranium (RU). One proposed solution for the recycled uranium is to use it as fuel in Candu reactors. This paper investigates the possibilities of transmuting americium in 'spiked' bundles in pressurized water reactors (PWRs) and in boiling water reactors (BWRs). Transmutation of Am in Candu reactors is also examined. One scenario studies a full core fuelled with homogeneous bundles of Am mixed with recycled uranium, while a second scenario places Am in an inert matrix in target channels in a Candu reactor, with the rest of the reactor fuelled with RU. A comparison of the transmutation in LWRs and HWRs is made, in terms of the fraction of Am that is transmuted and the impact on the decay heat of the spent nuclear fuel. CANDU{sup R} is a registered trademark of Atomic Energy of Canada Limited (AECL). (authors)