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Sample records for heavy-water thick targets

  1. Heavy water jet target and a beryllium target for production of fast neutrons

    International Nuclear Information System (INIS)

    Logan, C.M.; Anderson, J.D.; Barschall, H.H.; Davis, J.C.

    1975-01-01

    A limitation on the neutron flux obtainable from proton or deuteron induced reactions is the heating of the target by the accelerated charged particles. The heat can be removed more easily if the target moves. The possibility of using a rotating Be target and a heavy water jet as a target for bombardment by 35-MeV deuterons was studied. In a thick Be metal target moving at 10 m/sec through such a beam of 1 cm diameter a temperature pulse of about 300 0 C will be produced by the 0.3 MW beam. The Be target should be able to withstand such a temperature pulse. A Be target suitable for 3 MW of power in a 1 cm diameter beam would require internal cooling and a higher velocity. A free jet of heavy water is also a possible target. Laser photographs of water jets in vacuum show small angles of divergence. The effect of heating by a 0.3 MW beam is probably not important because the temperature rise produced by the beam is small compared to the absolute temperature of the unheated jet. (auth)

  2. Monitoring production target thickness

    International Nuclear Information System (INIS)

    Oothoudt, M.A.

    1993-01-01

    Pion and muon production targets at the Clinton P. Anderson Meson Physics Facility consist of rotating graphite wheels. The previous target thickness monitoring Procedure scanned the target across a reduced intensity beam to determine beam center. The fractional loss in current across the centered target gave a measure of target thickness. This procedure, however, required interruption of beam delivery to experiments and frequently indicated a different fractional loss than at normal beam currents. The new monitoring Procedure compares integrated ups and downs toroid current monitor readings. The current monitors are read once per minute and the integral of readings are logged once per eight-hour shift. Changes in the upstream to downstream fractional difference provide a nonintrusive continuous measurement of target thickness under nominal operational conditions. Target scans are now done only when new targets are installed or when unexplained changes in the current monitor data are observed

  3. Optimum target thickness for polarimeters

    International Nuclear Information System (INIS)

    Sitnik, I.M.

    2003-01-01

    Polarimeters with thick targets are a tool to measure the proton polarization. But the question about the optimum target thickness is still the subject of discussion. An attempt to calculate the most common parameters concerning this problem, in a few GeV region, is made

  4. 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

  5. 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.

  6. Uncertainties in thick-target PIXE analysis

    International Nuclear Information System (INIS)

    Campbell, J.L.; Cookson, J.A.; Paul, H.

    1983-01-01

    Thick-target PIXE analysis insolves uncertainties arising from the calculation of thick-target X-ray production in addition to the usual PIXE uncertainties. The calculation demands knowledge of ionization cross-sections, stopping powers and photon attenuation coefficients. Information on these is reviewed critically and a computational method is used to estimate the uncertainties transmitted from this data base into results of thick-target PIXE analyses with reference to particular specimen types using beams of 2-3 MeV protons. A detailed assessment of the accuracy of thick-target PIXE is presented. (orig.)

  7. 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

  8. 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

  9. Preparation of tantalum targets of known thicknesses

    International Nuclear Information System (INIS)

    Alexander, J.R.; Wirth, H.L.

    1985-01-01

    A series of carbon-backed tantalum targets were produced in a heavy ion sputtering system with a Penning ion source. The target thicknesses were then measured using the alpha-ray energy loss method. The resulting tabulated measurements were reproducible and make possible the production of carbon-backed tantalum targets with pre-determined thicknesses ranging from 20 μg/cm 2 to 1 mg/cm 2 . (orig.)

  10. Measurement of concentration of heavy water

    International Nuclear Information System (INIS)

    Tsukamoto, Yuichi; Kondo, Mitsuo; Sakurai, Naoyuki

    1979-01-01

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

  11. 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

  12. 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.)

  13. 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

  14. 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)

  15. 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

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

    International Nuclear Information System (INIS)

    Sanhueza M, A.

    1986-01-01

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

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

    International Nuclear Information System (INIS)

    Matsushita, T.; Susaki, S.

    1980-01-01

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

  18. 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

  19. The Canadian heavy water situation

    International Nuclear Information System (INIS)

    Dahlinger, A.

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

  20. 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)

  1. 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)

  2. 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

  3. Study of the heavy water regeneration processes

    International Nuclear Information System (INIS)

    Cavcic, E.

    1965-11-01

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

  4. 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

  5. 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)

  6. 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

  7. 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

  8. 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

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

    International Nuclear Information System (INIS)

    Matsushita, Tadashi; Iijima, Setsuo

    1980-01-01

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

  10. 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.

  11. 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.)

  12. 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.

  13. 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

  14. 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

  15. 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

  16. 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.)

  17. 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)

  18. Preparation of barium and uranium targets on thick backings

    International Nuclear Information System (INIS)

    Sletten, G.

    1982-01-01

    Targets of 135 Ba and 235 U have been prepared by the technique of heavy ion sputtering. Rolled foils of 208 Pb and 197 Au were used to support 250-500 μg/cm 2 layers of barium. Uranium films have been prepared by sputtering UO 2 onto 1 mg/cm 2 titanium foils. Uranium deposit thicknesses of 300 to 1800 μg/cm 2 have been prepared. (orig.)

  19. 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)

  20. 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.

  1. 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.

  2. 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

  3. 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)

  4. 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.)

  5. 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

  6. 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.)

  7. 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.)

  8. 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

  9. 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

  10. 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

  11. 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.))

  12. 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

  13. 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.

  14. 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

  15. 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)

  16. 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)

  17. 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

  18. 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)

  19. 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.)

  20. 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)

  1. Impact analysis and testing of tritiated heavy water transportation packages including hydrodynamic effects

    International Nuclear Information System (INIS)

    Sauve, R.G.; Tulk, J.D.; Gavin, M.E.

    1989-01-01

    Ontario Hydro has recently designed a new Type B(M) Tritiated Heavy Water Transportation Package (THWTP) for the road transportation of tritiated heavy water from its operating nuclear stations to the Tritium Removal Facility in Ontario. These packages must demonstrate the ability to withstand severe shock and impact scenarios such as those prescribed by IAEA standards. The package, shown in figure 1, comprises an inner container filled with tritiated heavy water, and a 19 lb/ft 3 polyurethane foam-filled overpack. The overpack is of sandwich construction with 304L stainless steel liners and 10.5 inch thick nominal foam walls. The outer shell is 0.75 inch thick and the inner shell is 0.25 inch thick. The primary containment boundary consists of the overpack inner liner, the containment lid and outer containment seals in the lid region. The total weight of the container including the 12,000 lb. payload is 36,700 lb. The objective of the present study is to evaluate the hydrodynamic effect of the tritiated heavy water payload on the structural integrity of the THWTP during a flat end drop from a height of 9 m. The study consisted of three phases: (i) developing an analytical model to simulate the hydrodynamic effects of the heavy water payload during impact; (ii) performing an impact analysis for a 9 m flat end drop of the THWTP including fluid structure interaction; (iii) verification of the analytical models by experiment

  2. 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)

  3. 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

  4. 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.)

  5. 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).

  6. 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

  7. 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)

  8. 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)

  9. 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)

  10. 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.)

  11. 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

  12. 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)

  13. 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.)

  14. 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.)

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

    International Nuclear Information System (INIS)

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

    1994-01-01

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

  16. Heavy water critical experiments on plutonium lattice

    International Nuclear Information System (INIS)

    Miyawaki, Yoshio; Shiba, Kiminori

    1975-06-01

    This report is the summary of physics study on plutonium lattice made in Heavy Water Critical Experiment Section of PNC. By using Deuterium Critical Assembly, physics study on plutonium lattice has been carried out since 1972. Experiments on following items were performed in a core having 22.5 cm square lattice pitch. (1) Material buckling (2) Lattice parameters (3) Local power distribution factor (4) Gross flux distribution in two region core (5) Control rod worth. Experimental results were compared with theoretical ones calculated by METHUSELAH II code. It is concluded from this study that calculation by METHUSELAH II code has acceptable accuracy in the prediction on plutonium lattice. (author)

  17. 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

  18. 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

  19. 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)

  20. Good practices in heavy water reactor operation

    International Nuclear Information System (INIS)

    2010-06-01

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

  1. 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)

  2. 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.)

  3. 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

  4. 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)

  5. 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)

  6. 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)

  7. 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.

  8. 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

  9. 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)

  10. 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

  11. Solubilities of boric acid in heavy water

    International Nuclear Information System (INIS)

    Nakai, Shigetsugu; Aoi, Hideki; Hayashi, Ken-ichi; Katoh, Taizo; Watanabe, Takashi.

    1988-01-01

    A gravimetric analysis using meta-boric acid (HBO 2 or DBO 2 ) as a weighing form has been developed for solubility measurement. The method gave satisfactory results in preliminary measurement of solubilities of boric acid in light water. By using this method, the solubilities of 10 B enriched D 3 BO 3 in heavy water were measured. The results are as follows; 2.67 (7deg C), 3.52 (15deg C), 5.70 (30deg C), 8.87 (50deg C) and 12.92 (70deg C) w/o, respectively. These values are about 10% lower than those in light water. Thermodynamical consideration based on the data shows that boric acid is the water structure breaker. (author)

  12. Surface tension of normal and heavy water

    International Nuclear Information System (INIS)

    Straub, J.; Rosner, N.; Grigull, V.

    1980-01-01

    A Skeleton Table and simple interpolation equation for the surface tension of light water was developed by the Working Group III of the International Association for the Properties of Steam and is recommended as an International Standard. The Skeleton Table is based on all known measurements of the surface tension and individual data were weighted corresponding to the accuracy of the measurements. The form of the interpolation equation is based on a physical concept. It represents an extension of van der Waals-equation, where the exponent conforms to the 'Scaling Laws'. In addition for application purposes simple relations for the Laplace-coefficient and for the density difference between the liquid and gaseous phases of light water are given. The same form of interpolation equation for the surface tension can be used for heavy water, for which the coefficients are given. However, this equation is based only on a single set of data. (orig.) [de

  13. Heavy water moderated gas-cooled reactors

    International Nuclear Information System (INIS)

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

    1964-01-01

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

  14. Dynamic modelling of Industrial Heavy Water Plant

    International Nuclear Information System (INIS)

    Teruel, F.E.

    1997-01-01

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

  15. 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

  16. 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

  17. 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)

  18. 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)

  19. Natural uranium lattice in heavy water

    International Nuclear Information System (INIS)

    Girard, Y.; Koechlin, J.C.; Moreau, J.; Naudet, R.

    1959-01-01

    A group of Laplacian determinations have been made under critical running conditions in a heavy water pile specially constructed to this end using either complete lattices or samples of lattices employing a two-zone method. The experimental equipment is briefly described: it has been devised to allow rapid modifications of the charge. The methods of measurement employed are also summarily described one operates either by flux charts in the case of lattices which are then used as references, or by progressive replacement of the bars by concentric rings and measurements of the reactivity. In this case, one attempts to obtain the difference between the material laplacian of the central unknown lattice and that of the reference lattice. The method has been specially develop ped to give precision. Results of Laplacian measurements for all these lattice types are presented, allowing the construction of a set of curves as a function of the separation. Various other effects have also been measured: the equivalent reactivity of a mm of water - anisotropy - temperature effect, etc. However in this first attack on the problem, the measurement of a large variety of Laplacian has been carried out, rather than careful measurements in particular cases. It is in this spirit that the interpretation of the results has been made. As a large number of very complex phenomena still escape the possibilities of the calculation, it is considered that a certain number of adjustments are necessary; now these can only give the desired efficiency in forecasting results if they refer to a sufficiently great number of experimental data. It is necessary then to connect the measurements closely on with the other whilst, at the same time, subdividing them according to logically deduced formulae. The principal source of trouble has been that of coherence. The rules governing the calculations employed in the interpretation of the data are given. In the first instance simple formula are used: first of

  20. 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

  1. Interactions of relativistic heavy ions in thick heavy element targets and some unresolved problems

    International Nuclear Information System (INIS)

    Brandt, R.; Ditlov, V.A.; Pozharova, E.A.; Smirnitskij, V.A.

    2005-01-01

    Interactions of relativistic heavy ions with total energies above 30 GeV in thick Cu and Pb targets (≥2 cm) have been studied with various techniques. Radiochemical irradiation experiments using thick Cu targets, both in a compact form or as diluted '2π-Cu targets' have been carried out with several relativistic heavy ions, such as 44 GeV 12 C (JINR, Dubna) and 72 GeV 40 Ar (LBL, Berkeley, USA). Neutron measuring experiments using thick targets irradiated with various relativistic heavy ions up to 44 GeV 12 C have been performed at JINR. In addition, the number of 'black prongs' in nuclear interactions (due to protons with energies less than 30 MeV and emitted from the target-like interaction partner at rest) produced with 72 GeV 22 Ne ions in nuclear emulsion plates has been measured in the first nuclear interaction of the primary 22 Ne ion and in the following second nuclear interaction of the secondary heavy (Z>1) ion. Some essential results have been obtained. 1) Spallation products produced by relativistic secondary fragments in interactions ([44 GeV 12 C or 72 GeV 40 Ar]+Cu) within thick copper yield less products close to the target and much more products far away from the target as compared to primary beam interactions. This applies also to secondary particles emitted into large angles (Θ>10deg). 2) The neutron production of 44 GeV 12 C within thick Cu and Pb targets is beyond the estimated yield as based on experiments with 12 GeV 12 C. These rather independent experimental results cannot be understood with well-accepted nuclear reaction models. They appear to present unresolved problems

  2. 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.

  3. 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

  4. 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.)

  5. 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.

  6. Production of heavy water in France

    International Nuclear Information System (INIS)

    Lerat, J.M.; Roth, E.

    1964-01-01

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

  7. Heavy water moderated reactors advances and challenges

    International Nuclear Information System (INIS)

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

    1994-01-01

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

  8. 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

  9. 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.

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

    International Nuclear Information System (INIS)

    Reny, J.P.

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

  11. 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

  12. 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

  13. 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)

  14. 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

  15. 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

  16. 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.

  17. 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.

  18. Measurement of neutron yield by 62 MeV proton beam on a thick Beryllium target

    International Nuclear Information System (INIS)

    Alba, R; Cosentino, G; Zoppo, A Del; Pietro, A Di; Figuera, P; Finocchiaro, P; Maiolino, C; Santonocito, D; Schillaci, M; Barbagallo, M; Colonna, N; Boccaccio, P; Esposito, J; Celentano, A; Osipenko, M; Ricco, G; Ripani, M; Viberti, C M; Kostyukov, A

    2013-01-01

    In the framework of research on IVth generation reactors and high intensity neutron sources a low-power prototype neutron amplifier was recently proposed by INFN. It is based on a low-energy, high current proton cyclotron, whose beam, impinging on a thick Beryllium converter, produces a fast neutron spectrum. The world database on the neutron yield from thick Beryllium target in the 70 MeV proton energy domain is rather scarce. The new measurement was performed at LNS, covering a wide angular range from 0 to 150 degrees and an almost complete neutron energy interval. In this contribution the preliminary data are discussed together with the proposed ADS facility.

  19. 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

  20. 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

  1. 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

  2. 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.

  3. 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.

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

    International Nuclear Information System (INIS)

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

    1989-01-01

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

  5. 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.

  6. 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

  7. 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

  8. 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)

  9. 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)

  10. 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)

  11. 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)

  12. 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)

  13. 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.)

  14. 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)

  15. 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

  16. 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)

  17. 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

  18. 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)

  19. 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)

  20. Measurement of resonances in 12 C + 4 He through inverse kinematics with thick targets

    International Nuclear Information System (INIS)

    Aguilera, E.F.; Lizcano, D.; Martinez Q, E.; Fernandez, M.C.; Murillo, G.; Goldberg, V.; Skorodumov, B.B.; Rogachev, G.

    2003-01-01

    The excitation function of elastic scattering for the system 12 C + 4 He to energy from 0.5 to 3.5 MeV in the center of mass system (c.m.) was measured. We use a gassy thick target and the technique of inverse kinematics which allows to make measurements at 180 degrees in c.m. Using the R matrix theory those was deduced parameters of the resonances and the results were compared with measurements reported in the literature made with other techniques. (Author)

  1. Neutron energy spectra from the thick target 9Be(d,n)10B reaction

    International Nuclear Information System (INIS)

    Whittlestone, S.

    1976-12-01

    The energy spectrum of neutrons emitted when deuterons impinge on a thick beryllium target has been measured using an NE213 scintillation detector and the time-of-flight technique. Spectra were measured at angles of 0, 30, 45, 60, 90, 120 and 150 0 for deuteron energies of 1.4, 1.8, 2.3 and 2.8 MeV. Tables are presented of these angle-dependent energy spectra, the angle-integrated energy dependent yeidls, and the total neutron yield as a function of deuteron energy. (author)

  2. 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)

  3. Possibility of using metal uranium fuel in heavy water reactors

    International Nuclear Information System (INIS)

    Djuric, B.; Mihajlovic, A.; Drobnjak, Dj.

    1965-01-01

    The review of metal uranium properties including irradiation in the reactor core lead to the following conclusions. Using metal uranium in the heavy water reactors would be favourable from economic point of view for ita high density, i.e. high conversion factor and low cost of fuel elements fabrication. Most important constraint is swelling during burnup and corrosion

  4. 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

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

    International Nuclear Information System (INIS)

    Martin, D.E.

    2008-01-01

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

  6. 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

  7. 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)

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

    International Nuclear Information System (INIS)

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

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

  9. 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

  10. 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

  11. Decommissioning of the NPP A-1 heavy water management system

    International Nuclear Information System (INIS)

    Medved, J.; Rezbarik, J.; Vargovcik, L.; Vykukel, I.

    2015-01-01

    The paper deals with experience and techniques in the application of decontamination technology and remotely controlled robotic devices for the decontamination and dismantling of the heavy water management system during undergoing decommissioning process of the A-1 NPP as well as treatment of arising liquid waste All of these activities are characterized by high level of radioactivity and contamination. (authors)

  12. (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

  13. Energy conservation and management strategies in Heavy Water Plants

    International Nuclear Information System (INIS)

    Kamath, H.S.

    2002-01-01

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

  14. 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)

  15. 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)

  16. 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 ≤ Eα ≤ 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.

  17. Neutron energy spectra produced by α-bombardment of light elements in thick targets

    International Nuclear Information System (INIS)

    Jacobs, G.J.H.

    1982-01-01

    The aim of the work, presented in this thesis, is to determine energy spectra of neutrons produced by α-particle bombardment of thick targets containing light elements. These spectra are required for nuclear waste management. The set-up of the neutron spectrometer is described, and its calibration discussed. Absolute efficiencies were determined at various neutron energies, using monoenergetic neutrons produced with the Van de Graaff accelerator in pulsed mode. The additional calibration of the neutron spectrometer as proton-recoil spectrometer was carried out primarily for future applications in measurements where no pulsed neutron source is available or the neutron flux density is too low. The basis for an accurate uncertainty analysis is made by the determination of the covariance matrix for the uncertainties in the efficiencies. The determination of the neutron energy spectra from time-of-flight and from proton-recoil measurements is described. A comparison of the results obtained from the two different types of measurements is made. The experimentally determined spectra were compared with spectra calculated from stopping powers and theoretically determined cross sections. These cross sections were calculated from optical model parameters and level parameters using the Hauser-Feshbach formalism. Measurements were carried out on thick targets of silicon, aluminium, magnesium, carbon, boron nitride, calcium fluoride, aluminium oxide, silicon oxide and uranium oxide at four different α-particle energies. (Auth.)

  18. Thin and thick targets for radioactive ion beam production at SPIRAL1 facility

    Science.gov (United States)

    Jardin, P.; Bajeat, O.; Delahaye, P.; Dubois, M.; Kuchi, V.; Maunoury, L.

    2018-05-01

    The upgrade of the Système de Production d'Ions Radioactifs Accélérés en Ligne (SPIRAL1) facility will deliver its new Radioactive Ion Beams (RIB) by summer 2017. The goal of the upgrade is an improvement of the performances of the installation in terms of isotopes species and ion charge states [1]. Ion beams are produced using the Isotope Separator On Line Method, consisting in an association of a primary beam of stable ions, a hot target and an ion source. The primary beam impinges on the material of the target. Radioactive isotopes are produced by nuclear reactions and propagate up to the source, where they are ionized and accelerated to create a RIB. One advantage of SPIRAL1 driver is the variety of its available primary beams, from carbon to uranium with energies up to 95 MeV/A. Within the SPIRAL1 upgrade, they will be combined with targets made of a large choice of materials, extending in this way the number of possible nuclear reactions (fusion-evaporation, transfer, fragmentation) for producing a wider range of isotopes, up to regions of the nuclide chart still scarcely explored. Depending on the reaction process, on the collision energy and on the primary beam power, thin and thick targets are used. As their functions can be different, their design must cope with specific constraints which will be described. After a presentation of the goals of present and future SPIRAL1 Target Ion Source System, the main target features, studies and designs under progress are presented.

  19. Neutron energy spectrum from 120 GeV protons on a thick copper target

    Energy Technology Data Exchange (ETDEWEB)

    Shigyo, Nobuhiro; /Kyushu U.; Sanami, Toshiya; /KEK, Tsukuba; Kajimoto, Tsuyoshi; /Kyushu U.; Iwamoto, Yosuke; /JAEA, Ibaraki; Hagiwara, Masayuki; Saito, Kiwamu; /KEK, Tsukuba; Ishibashi, Kenji; /Kyushu U.; Nakashima, Hiroshi; Sakamoto, Yukio; /JAEA, Ibaraki; Lee, Hee-Seock; /Pohang Accelerator Lab.; Ramberg, Erik; /Fermilab

    2010-08-01

    Neutron energy spectrum from 120 GeV protons on a thick copper target was measured at the Meson Test Beam Facility (MTBF) at Fermi National Accelerator Laboratory. The data allows for evaluation of neutron production process implemented in theoretical simulation codes. It also helps exploring the reasons for some disagreement between calculation results and shielding benchmark data taken at high energy accelerator facilities, since it is evaluated separately from neutron transport. The experiment was carried out using a 120 GeV proton beam of 3E5 protons/spill. Since the spill duration was 4 seconds, protoninduced events were counted pulse by pulse. The intensity was maintained using diffusers and collimators installed in the beam line to MTBF. The protons hit a copper block target the size of which is 5cm x 5cm x 60 cm long. The neutrons produced in the target were measured using NE213 liquid scintillator detectors, placed about 5.5 m away from the target at 30{sup o} and 5 m 90{sup o} with respect to the proton beam axis. The neutron energy was determined by time-of-flight technique using timing difference between the NE213 and a plastic scintillator located just before the target. Neutron detection efficiency of NE213 was determined on basis of experimental data from the high energy neutron beam line at Los Alamos National Laboratory. The neutron spectrum was compared with the results of multiparticle transport codes to validate the implemented theoretical models. The apparatus would be applied to future measurements to obtain a systematic data set for secondary particle production on various target materials.

  20. 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

  1. 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

  2. Bremsstrahlung spectra from thick-target electron beams with noncollisional energy losses

    International Nuclear Information System (INIS)

    Brown, J.C.; MacKinnon, A.L.

    1985-01-01

    We consider what can be learned from the bremsstrahlung radiation of fast electrons in a thick target, generalized to include electron energy losses additional to collisions. We show that the observed photon spectrum can, in principle, be inverted to yield an integral functional of the electron spectrum and the effective energy loss rate. In the light of this result, there seems no reason to suppose, in the absence of a priori information to the contrary, that the photon spectrum is symptomatic more of the fast electron distribution than of the energy loss processes. In cases where the electron injection spectrum is known on independent observational or theoretical grounds, it is possible to infer an effective, ''phenomenological'' energy loss function. In the more general case, however, fullest possible modeling of the physical situation and comparison of the resulting spectrum with observations is all that can be attempted

  3. Thick-target Pixe analysis of chromium, copper and arsenic impregnated lumber

    International Nuclear Information System (INIS)

    Saarela, K-E.; Harju, L.; Lill, J-O.; Rajander, J.; Lindroos, A.; Heselius, S-J.

    1999-01-01

    Chromium, copper and arsenic (CCA) have for decades been used for wood preservation. Of these elements especially arsenic is very toxic. As CCA impregnated wood is still today used for many construction purposes, a monitoring of these metal ions is of great environmental importance. Thick-target PIXE is a powerful method for the determination of trace metals in wood. The TTPIXE method enabled study of variations of the elemental concentrations in lumber treated with CCA impregnation solution. Distribution patterns were obtained for both naturally occurring elements and elements introduced in the treatment process. During the impregnation process a desorption of e.g. alkali metal ions takes place from the wood. The sensitivity of the method is improved by dry ashing of the samples prior to PIXE analysis. The TTPIXE method was calibrated and validated using international certified reference materials (CRM) based on wood material

  4. Local re-acceleration and a modified thick target model of solar flare electrons

    Science.gov (United States)

    Brown, J. C.; Turkmani, R.; Kontar, E. P.; MacKinnon, A. L.; Vlahos, L.

    2009-12-01

    Context: The collisional thick target model (CTTM) of solar hard X-ray (HXR) bursts has become an almost “standard model” of flare impulsive phase energy transport and radiation. However, it faces various problems in the light of recent data, particularly the high electron beam density and anisotropy it involves. Aims: We consider how photon yield per electron can be increased, and hence fast electron beam intensity requirements reduced, by local re-acceleration of fast electrons throughout the HXR source itself, after injection. Methods: We show parametrically that, if net re-acceleration rates due to e.g. waves or local current sheet electric (E) fields are a significant fraction of collisional loss rates, electron lifetimes, and hence the net radiative HXR output per electron can be substantially increased over the CTTM values. In this local re-acceleration thick target model (LRTTM) fast electron number requirements and anisotropy are thus reduced. One specific possible scenario involving such re-acceleration is discussed, viz, a current sheet cascade (CSC) in a randomly stressed magnetic loop. Results: Combined MHD and test particle simulations show that local E fields in CSCs can efficiently accelerate electrons in the corona and and re-accelerate them after injection into the chromosphere. In this HXR source scenario, rapid synchronisation and variability of impulsive footpoint emissions can still occur since primary electron acceleration is in the high Alfvén speed corona with fast re-acceleration in chromospheric CSCs. It is also consistent with the energy-dependent time-of-flight delays in HXR features. Conclusions: Including electron re-acceleration in the HXR source allows an LRTTM modification of the CTTM in which beam density and anisotropy are much reduced, and alleviates theoretical problems with the CTTM, while making it more compatible with radio and interplanetary electron numbers. The LRTTM is, however, different in some respects such as

  5. 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.

  6. 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

  7. 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

  8. 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)

  9. 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)

  10. 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

  11. Integrated inspection programs at Bruce Heavy Water Plant

    International Nuclear Information System (INIS)

    Brown, K.C.

    1992-01-01

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

  12. Gas stripping and recirculation process in heavy water separation plant

    International Nuclear Information System (INIS)

    Nazzer, D.B.; Thayer, V.R.

    1976-01-01

    Hydrogen sulfide is stripped from hot effluent, in a heavy water separation plant of the dual temperature isotope separation type, by taking liquid effluent from the hot tower before passage through the humidifier, passing the liquid through one or more throttle devices to flash-off the H 2 S gas content, and feeding the gas into an absorption tower containing incoming feed water, for recycling of the gas through the process

  13. Possibilities of using metal uranium fuel in heavy water reactors

    International Nuclear Information System (INIS)

    Djuric, B.; Mihajlovic, A.; Drobnjak, Dj.

    1965-11-01

    There are serious economic reasons for using metal uranium in heavy water reactors, because of its high density, i.e. high conversion factor, and low cost of fuel elements production. Most important disadvantages are swelling at high burnup and corrosion risk. Some design concepts and application of improved uranium obtained by alloying are promising for achievement of satisfactory stability of metal uranium under reactor operation conditions [sr

  14. Integrated inspection programs at Bruce Heavy Water Plant

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-12-31

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

  15. Heavy water standards. Qualitative analyses, sample treating, stocking and manipulation

    International Nuclear Information System (INIS)

    Pavelescu, M.; Steflea, D.; Mihancea, I.; Varlam, M.; Irimescu, R.

    1995-01-01

    This paper presents methods and procedures for measuring heavy water concentration, and also sampling, stocking and handling of samples to be analysed. The main concentration analysis methods are: mass spectrometry, for concentrations less then 1%, densitometry, for concentrations within the range 1% - 99% and infrared spectrometry for concentrations above 99%. Procedures of sampling, processing and purification appropriate to these measuring methods were established. 1 Tab

  16. Heavy water reactors on the once-through uranium cycle

    International Nuclear Information System (INIS)

    1978-05-01

    This paper presents preliminary technical and economic data to INFCE on the once-through uranium fuel cycle for use in early comparisons of alternate nuclear systems. The denatured thorium fuel cycle is discussed in a companion paper. Information for this paper was developed under an ongoing program, and more complete reporting of the evaluation of the heavy water reactor and its fuel cycles is planned toward the end of the year

  17. 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

  18. 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.)

  19. 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.

  20. 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

  1. 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

  2. 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...

  3. 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

  4. 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

  5. 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

  6. Bibliography of published papers on neutron and photon emission from thick or thin target bombarded by charged particles

    International Nuclear Information System (INIS)

    Nakamura, Takashi; Furuta, Yutaka; Sato, Kazuo; Kawachi, Kiyomitsu; Hirayama, Hideo.

    1981-09-01

    Papers describing about secondary particles, especially neutrons and photons, produced by a thick or thin target are surveyed. The survey covers twelve kinds of journals mainly from 1965 to 1980, and brief descriptions are listed about type of accelerator, projectile and target used, measurements and calculations, and quantities obtained. (author)

  7. Optimum design of beam window's diameter and thickness of Hyper target system

    International Nuclear Information System (INIS)

    Cho, C. H.; Tak, N. I.; Song, T. Y.; Park, W. S.

    2002-01-01

    HYPER is designed to transmute long-lived TRU and fission products such as Tc-99 and I-129. Pb-Bi is used as the coolant and spallation target material at the same time. HYPER is expected to need about 20mA proton beam to sustain a 1000MW th power level. The cylindrical beam tube and spherical window is adopted as the basic window shape of HYPER. The window diameter and the window thickness are varied to find the maximum allowable current based on the design criteria : Pb-Bi temperature < 500 .deg. C, window temperature < 600 .deg. C, Pb-Bi velocity < 2m/s and window stress < 160MPa. The LAHET code is used to simulate heat generation. CFX is also used for the thermal-hydraulics calculation. Based on our design criteria, the maximum allowable current is calculated to be about 9.2mA, which is smaller than the required current. Therefore, an upgrade of the target system design is required

  8. Precise measurements of the thick target neutron yields of the 7Li(p,n) reaction

    International Nuclear Information System (INIS)

    Matysiak, W.; Prestwich, W.V.; Byun, S.H.

    2011-01-01

    Thick target neutron yield of the 7 Li(p,n) 7 Be reaction was measured in the proton energy range from 1.95 to 2.3 MeV by determining induced activity of the 7 Be. A HPGe detector was used to detect the 478 keV gamma-rays emitted through 7 Be decay. A series of irradiations with nominal proton energies of 1.95, 2.0, 2.1, 2.2, and 2.3 MeV were carried out. In an independent experiment, raw neutron spectra were collected by a 3 He ion chamber for the same series of proton energies. From the raw neutron spectra, it was noted, that the effective proton energies were lower than the nominal by 50-58 keV. After corrections for the proton energy offsets were applied, the measured neutron yields matched the analytically calculated yields within 20%. Long term stability of neutron yield was tested at two nominal proton energies, 2.1 and 1.95 MeV over an experimental period of one year. The results show that the yield at 2.1 MeV was stable within rmse variation coefficient of 4.7% and remained consistent even when the lithium target was replaced, whereas at 1.95 MeV, the maximum fluctuations reached a factor of 10.

  9. 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

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  11. 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)

  12. Benchmarking of Monte Carlo simulation of bremsstrahlung from thick targets at radiotherapy energies

    International Nuclear Information System (INIS)

    Faddegon, Bruce A.; Asai, Makoto; Perl, Joseph; Ross, Carl; Sempau, Josep; Tinslay, Jane; Salvat, Francesc

    2008-01-01

    Several Monte Carlo systems were benchmarked against published measurements of bremsstrahlung yield from thick targets for 10-30 MV beams. The quantity measured was photon fluence at 1 m per unit energy per incident electron (spectra), and total photon fluence, integrated over energy, per incident electron (photon yield). Results were reported at 10-30 MV on the beam axis for Al and Pb targets and at 15 MV at angles out to 90 degree sign for Be, Al, and Pb targets. Beam energy was revised with improved accuracy of 0.5% using an improved energy calibration of the accelerator. Recently released versions of the Monte Carlo systems EGSNRC, GEANT4, and PENELOPE were benchmarked against the published measurements using the revised beam energies. Monte Carlo simulation was capable of calculation of photon yield in the experimental geometry to 5% out to 30 degree sign , 10% at wider angles, and photon spectra to 10% at intermediate photon energies, 15% at lower energies. Accuracy of measured photon yield from 0 to 30 degree sign was 5%, 1 s.d., increasing to 7% for the larger angles. EGSNRC and PENELOPE results were within 2 s.d. of the measured photon yield at all beam energies and angles, GEANT4 within 3 s.d. Photon yield at nonzero angles for angles covering conventional field sizes used in radiotherapy (out to 10 degree sign ), measured with an accuracy of 3%, was calculated within 1 s.d. of measurement for EGSNRC, 2 s.d. for PENELOPE and GEANT4. Calculated spectra closely matched measurement at photon energies over 5 MeV. Photon spectra near 5 MeV were underestimated by as much as 10% by all three codes. The photon spectra below 2-3 MeV for the Be and Al targets and small angles were overestimated by up to 15% when using EGSNRC and PENELOPE, 20% with GEANT4. EGSNRC results with the NIST option for the bremsstrahlung cross section were preferred over the alternative cross section available in EGSNRC and over EGS4. GEANT4 results calculated with the ''low energy

  13. Benchmarking of Monte Carlo simulation of bremsstrahlung from thick targets at radiotherapy energies

    Energy Technology Data Exchange (ETDEWEB)

    Faddegon, Bruce A.; Asai, Makoto; Perl, Joseph; Ross, Carl; Sempau, Josep; Tinslay, Jane; Salvat, Francesc [Department of Radiation Oncology, University of California at San Francisco, San Francisco, California 94143 (United States); Stanford Linear Accelerator Center, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); National Research Council Canada, Institute for National Measurement Standards, 1200 Montreal Road, Building M-36, Ottawa, Ontario K1A 0R6 (Canada); Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya and Centro de Investigacion Biomedica en Red en Bioingenieria, Biomateriales y Nanomedicina (CIBER-BBN), Diagonal 647, 08028 Barcelona (Spain); Stanford Linear Accelerator Center, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Facultat de Fisica (ECM), Universitat de Barcelona, Societat Catalana de Fisica (IEC), Diagonal 647, 08028 Barcelona (Spain)

    2008-10-15

    Several Monte Carlo systems were benchmarked against published measurements of bremsstrahlung yield from thick targets for 10-30 MV beams. The quantity measured was photon fluence at 1 m per unit energy per incident electron (spectra), and total photon fluence, integrated over energy, per incident electron (photon yield). Results were reported at 10-30 MV on the beam axis for Al and Pb targets and at 15 MV at angles out to 90 degree sign for Be, Al, and Pb targets. Beam energy was revised with improved accuracy of 0.5% using an improved energy calibration of the accelerator. Recently released versions of the Monte Carlo systems EGSNRC, GEANT4, and PENELOPE were benchmarked against the published measurements using the revised beam energies. Monte Carlo simulation was capable of calculation of photon yield in the experimental geometry to 5% out to 30 degree sign , 10% at wider angles, and photon spectra to 10% at intermediate photon energies, 15% at lower energies. Accuracy of measured photon yield from 0 to 30 degree sign was 5%, 1 s.d., increasing to 7% for the larger angles. EGSNRC and PENELOPE results were within 2 s.d. of the measured photon yield at all beam energies and angles, GEANT4 within 3 s.d. Photon yield at nonzero angles for angles covering conventional field sizes used in radiotherapy (out to 10 degree sign ), measured with an accuracy of 3%, was calculated within 1 s.d. of measurement for EGSNRC, 2 s.d. for PENELOPE and GEANT4. Calculated spectra closely matched measurement at photon energies over 5 MeV. Photon spectra near 5 MeV were underestimated by as much as 10% by all three codes. The photon spectra below 2-3 MeV for the Be and Al targets and small angles were overestimated by up to 15% when using EGSNRC and PENELOPE, 20% with GEANT4. EGSNRC results with the NIST option for the bremsstrahlung cross section were preferred over the alternative cross section available in EGSNRC and over EGS4. GEANT4 results calculated with the &apos

  14. 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

  15. Measurement of neutron yield by 62 MeV proton beam on a thick beryllium target

    Energy Technology Data Exchange (ETDEWEB)

    Osipenko, M., E-mail: osipenko@ge.infn.it [INFN, sezione di Genova, 16146 Genova (Italy); Ripani, M. [INFN, sezione di Genova, 16146 Genova (Italy); Alba, R. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Ricco, G. [INFN, sezione di Genova, 16146 Genova (Italy); Schillaci, M. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Barbagallo, M. [INFN, sezione di Bari, 70126 Bari (Italy); Boccaccio, P. [INFN, Laboratori Nazionali di Legnaro, 35020 Legnaro (Italy); Celentano, A. [Dipartimento di Fisica dell' Università di Genova, 16146 Genova (Italy); Colonna, N. [INFN, sezione di Bari, 70126 Bari (Italy); Cosentino, L.; Del Zoppo, A.; Di Pietro, A. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Esposito, J. [INFN, Laboratori Nazionali di Legnaro, 35020 Legnaro (Italy); Figuera, P.; Finocchiaro, P. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Kostyukov, A. [Moscow State University, Moscow 119992 (Russian Federation); Maiolino, C.; Santonocito, D.; Scuderi, V. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Viberti, C.M. [Dipartimento di Fisica dell' Università di Genova, 16146 Genova (Italy)

    2013-09-21

    The design of a low-power prototype of neutron amplifier recently proposed within the INFN-E project indicated the need for more accurate data on the neutron yield produced by a proton beam with energy of about 70 MeV impinging on a thick beryllium target. Such measurement was performed at the LNS superconducting cyclotron, covering a wide angular range from 0° to 150° and a complete neutron energy interval from thermal to beam energy. Neutrons with energy above 0.5 MeV were measured by liquid scintillators exploiting their time of flight to determine the kinetic energy. For lower energy neutrons, down to thermal energy, a {sup 3}He detector was used. The obtained data are in good agreement with previous measurements at 0° using 66 MeV proton beam, covering neutron energies >10MeV, as well as with measurements at few selected angles using protons of 46, 55 and 113 MeV energy. The present results extend the neutron yield data in the 60–70 MeV beam energy range. A comparison of measured yields to MCNP, FLUKA and Geant4 Monte Carlo simulations was performed.

  16. 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.)

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

    International Nuclear Information System (INIS)

    1978-01-01

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

  18. Neutron emission during lithium deuteride hydration in heavy water

    International Nuclear Information System (INIS)

    Arzhannikov, A.V.; Kezerashvili, G.Ya.; Muratov, V.V.; Sinitskij, S.L.

    1989-01-01

    An experiment on neutron detection during lithium deuteride hydration in heavy water using a system of SNM-17 or SNM-18 gas counters was set up. Signals were simultaneously detected by 6 counters and the data were stored in a computer. At the same time the temperature of the reaction ampule external surface was measured. It was found that the neutron number per 1 gram of lithium deuteride reacted with water in the ampule was equal to several dozens if their initial energy was about 2.5 MeV. 4 refs.; 2 figs

  19. Heavy water GS process R and D achievements

    International Nuclear Information System (INIS)

    Bancroft, A.R.

    1978-10-01

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

  20. Core construction in a pressure tube type heavy water reactor

    International Nuclear Information System (INIS)

    Ueda, Makoto; Aoki, Katsutada.

    1975-01-01

    Object: To replace a centrally positioned fuel assembly of a fuel assembly unit with a reactor controlling machinery to decrease a distance between the fuel assemblies thereby saving use of heavy water and enhancing economy. Structure: A centrally positioned fuel assembly of a fuel assembly unit, which is composed of a plurality of fuel assemblies orderly arranged in lattice fashion, is replaced with a reactor controlling members such as control rods, poison tubes and the like to provide an arrangement of lattice-free type fuel assembly, thus reducing the pitch as small as possible. (Kamimura, M.)

  1. Search for neutron emission during the electrolysis of heavy water

    International Nuclear Information System (INIS)

    Coelho, P.R.P.; Saxena, R.N.; Morato, S.P.; Goldman, I.D.; Pinho, A.G. de; Nascimento, I.C.

    1990-03-01

    A liquid scintillator detector NE 213 with pulse shape discrimination technique was used to observe neutrons during the electrolysis of heavy water with a palladium cathode. From the measured fore and background couting rates, a neutron emission rate of (8.2 ± 2.9) x 10 -3 n/(sec.g.) Pd was determined implying (2.9 ± 1.0) x 10 -24 fusions / [(dd pair).sec.] as compared to ≅ 10 -23 fusion/ [(dd pair).sec.] reported by Jones et al. using titanium electrode. (author) [pt

  2. The spectrographic analysis of inorganic impurities in heavy water

    International Nuclear Information System (INIS)

    Artaud, J.; Normand, J.; Vie, R.

    1961-01-01

    Inorganic impurities in heavy water are determined by two spectrographic methods. First is described the copper-spark method which is sensitive and directly applicable, and is particular useful because of the absence of a support. Secondly the graphite impregnation method is given; this is used when the first method is not applicable (determination of copper) and for the alkali metals. For the usual elements, the sensitivity of the copper spark method is of the order of 0,1 μg/ml whereas for the graphite impregnation method the sensitivity is only 0,3 μg/ml. (author) [fr

  3. Advances in commercial heavy water reactor power stations

    International Nuclear Information System (INIS)

    Brooks, G.L.

    1987-01-01

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

  4. 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

  5. Fast neutron forward distributions from C, Be and U thick targets bombarded by deuterons

    International Nuclear Information System (INIS)

    Menard, S.; Clapier, F.; Pauwels, N.; Proust, J.; Donzaud, C.; Guillemaud-Mueller, D.; Lhenry, I.; Mueller, A.C.; Scarpaci, J.A.; Sorlin, O.; Mirea, M.

    1999-01-01

    In principle, to produce neutron rich radioactive beams with sufficient intensities, a source of isotopes far from the valley of β--stability can be obtained through the fission of 238 U induced by fast neutrons. A very promising way to assess the feasibility of these very intense neutron beams is to break an intense 2 H beam in a dedicated converter. The main objective of SPIRAL and PARRNe R - D projects is the investigation of the optimum parameters for a neutron rich isotope source in accordance with the scheme presented above. In such conditions, the charge particle energy loss can prevent the destruction of the fission target. In the frame of these project, a special attention is dedicated to the energetic and angular distributions of the neutrons emerging from a set of converters at a series of 2 H incident energies. Deuteron beams at energies less than 30 MeV are particularly interesting because it is expected that, after the decay in the 238 U target, the neutron rich radioactive fission products are cold enough, thus avoiding the evaporation of a too large number of neutrons. For such purposes, one needs experimental angular distributions at given energies for different types of converters and to elaborate a theoretical tool in order to estimate accurately the characteristics of the secondary neutron beam. In this paper, the experimental results were obtained with 17, 20 and 28 MeV deuteron energies on Be, C and U converters using the time of flight method. These data are compared to results given by a model valid at higher energy in order to obtain pertinent simulations in a large range of incident energies. Many theoretical tools were developed to characterize the properties of the neutron beams emerging from thick targets. In this contribution the Serber's model, considered with its improvements which account for the Coulomb deflection and the mean straggling of the beam in the material, is compared to experimental data in order to verify the validity

  6. 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)

  7. 20% inlet header break analysis of Advanced Heavy Water Reactor

    International Nuclear Information System (INIS)

    Srivastava, A.; Gupta, S.K.; Venkat Raj, V.; Singh, R.; Iyer, K.

    2001-01-01

    The proposed Advanced Heavy Water Reactor (AHWR) is a 750 MWt vertical pressure tube type boiling light water cooled and heavy water moderated reactor. A passive design feature of this reactor is that the heat removal is achieved through natural circulation of primary coolant at all power levels, with no primary coolant pumps. Loss of coolant due to failure of inlet header results in depressurization of primary heat transport (PHT) system and containment pressure rise. Depressurization activates various protective and engineered safety systems like reactor trip, isolation condenser and advanced accumulator, limiting the consequences of the event. This paper discusses the thermal hydraulic transient analysis for evaluating the safety of the reactor, following 20% inlet header break using RELAP5/MOD3.2. For the analysis, the system is discretized appropriately to simulate possible flow reversal in one of the core paths during the transient. Various modeling aspects are discussed in this paper and predictions are made for different parameters like pressure, temperature, steam quality and flow in different parts of the Primary Heat Transport (PHT) system. Flow and energy discharges into the containment are also estimated for use in containment analysis. (author)

  8. 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

  9. 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.

  10. Heavy water handbook. Evaluation of available thermophysical properties of heavy water (D2O) liquid and vapour

    International Nuclear Information System (INIS)

    Bukovsky, J.; Haack, K.; Wiig, P.

    1993-01-01

    Numerous publications on the thermophysical data of heavy water (D 2 O) have been published since D 2 O became commercially available in the 1930's. Some of these data are in mutual disagreement. This has led to confusion among the scientifical and technical staffs who needed the information on the D 2 O thermophysical data. Correct thermophysical data must be consistent, i.e. their mutual relations must be in accordance to the fundamental thermophysical laws. The work behind this publication has been focussed at collecting all avalilable D 2 O data and checking the data mutually by means of these fundamental thermophysical criteria. Depending on the various production methods, the oxygen content of the D 2 O is enriched more or less in the heavier oxygen isotopes 17 O and 18 O. This, together with the amount of impurities and dissolved gases in the D 2 O samples of the various references, might - to some extent - explain the discrepancies between the data sources. Only a few references contain information on these subjects. The D 2 O data sets which were found to be the most reliable are presented in chapter 9, in tables as well as in diagrams, together with the corresponding H 2 O data for comparison. The diagrams are commented for reliability where it was found necessary. Furthermore, the publication contains short descriptions on the heavy water sources, availability, production processes, economy, material and energy demands for production. A comprehensive list of references is enclosed. (author)

  11. Heavy water handbook. Evaluation of presently available thermophysical properties of heavy water (D2O) liquid and vapour

    International Nuclear Information System (INIS)

    Bukovsky, J.; Haack, K.

    1994-08-01

    Many publication on the thermophysical properties of heavy water (D 2 O) have appeared since D 2 O became commercially available in the 1930's. Some for the data contradict one another and this has led to confusion when information is needed on D 2 O thermophysical data. Correct thermophysical data must be consistent, i.e. their mutual dependence must be consistent with fundamental thermophysical laws. The work behind this publication has focused on collecting all available D 2 O data and checking them against these fundamental thermophysical criteria. Depending on the various production methods for D 2 O, its oxygen content is enriched more or less by the heavier oxygen isotopes 17 O and 18 O. This, together with the amount of impurities and dissolved gases in the D 2 O samples of the various references, might - to some extent - explain the discrepancies found between the data. Only a few references contain information on these subjects. The D 2 O data sets found to be the most reliable are presented in Chapter 9, in tables as well as in diagrams, together with the corresponding H 2 O data for comparison. Comments on the reliability of the diagrams are given where necessary. Furthermore, short descriptions are given of heavy water sources, availability, production processes, economy, material and energy requirements for the production process. Finally a comprehensive list of references and an author index are included. (au)

  12. 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)

  13. 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)

  14. 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)

  15. 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)

  16. 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

  17. Removal and recovery of tritium from light and heavy water

    International Nuclear Information System (INIS)

    Butler, J.P.; Hammerli, M.

    1979-01-01

    A method and apparatus for removing tritium from light water are described, comprising contacting tritiated feed water in a catalyst column in countercurrent flow with hydrogen gas originating from an electrolysis cell so as to enrich this feed water with tritium from the electrolytic hydrogen gas and passing the tritium enriched water to an electrolysis cell wherein the electrolytic hydrogen gas is generated and then fed upwards through the catalyst column or recovered as product. The tritium content of the hydrogen gas leaving the top of the enricher catalyst column is further reduced in a stripper column containing catalyst which transfers the tritium to a countercurrent flow of liquid water. Anodic oxygen and water vapour from the anode compartment may be fed to a drier and condensed electrolyte recycled with a slip stream or recovered as a further tritium product stream. A similar method involving heavy water is also described. (author)

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

    International Nuclear Information System (INIS)

    Alp, E.; Ciccone, A.

    1995-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-06-01

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

  20. A new catalyst for heavy water production and its prospect

    International Nuclear Information System (INIS)

    Sato, Toshio; Ohkoshi, Sumio; Takahashi, Tomiki

    1978-01-01

    The heavy water production process utilizing isotope exchange reaction between liquid water and hydrogen is the most promising method. Study was made for developing highly active and long life catalyst practically applied for this process. As platinum is used as this catalyst, catalytic activities using varieties of Polapacs and Shodexes instead of active carbon as the carriers of platinum catalyst were investigated. It became clear that the catalytic activity using Pt/Shodex 104 (3 wt %) was 1000 times as high as the activity using Pt/active carbon (1 wt %). This method is considered to be reasonable enough economically. There are many problems which must be solved hereafter for its practical use, and the further studies are required regarding the following points; forming of catalyst, life of catalyst, mass production of catalyst, most appropriate counter flow reacting device of hydrophobic catalyst, pressure and temperature effects on reaction. (Kobatake, H.)

  1. 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).

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-07-01

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

  3. Neutron yield of thick {sup 12}C and {sup 13}C targets with 20 and 30 MeV deuterons

    Energy Technology Data Exchange (ETDEWEB)

    Lhersonneau, G.; Fadil, M. [GANIL, Caen (France); Malkiewicz, T. [CSC - IT Center for Science Ltd., Espoo (Finland); Gorelov, D.; Sorri, J.; Trzaska, W.H. [University of Jyvaskyla, Department of Physics, Jyvaskyla (Finland); Jones, P.; Ngcobo, P.Z. [iThemba Laboratory for Accelerator Based Science, Western Cape (South Africa)

    2016-12-15

    The neutron yield of thick targets of carbon, natural and enriched in {sup 13}C, bombarded by deuterons of 20 and 30 MeV has been measured by the activation method. The gain with respect to a {sup 12}C target is the same as with protons beams. The yield ratio is about 1.2 only and hardly can justify the use of a {sup 13}C target with deuteron beams. The data, apart from being of interest for the design of facilities where secondary neutron beams are used, provide a test case for calculations where both beam and target have a weakly bound neutron. The MCNPx code version 2.6.0, despite failing to reproduce some details of the experimental distributions, describes their global properties fairly well, especially the relative yields of the {sup 12}C and {sup 13}C targets. (orig.)

  4. Fuel enrichment reduction for heavy water moderated research reactors

    International Nuclear Information System (INIS)

    McCulloch, D.B.

    1984-01-01

    Twelve heavy-water-moderated research reactors of significant power level (5 MW to 125 MW) currently operate in a number of countries, and use highly enriched uranium (HEU) fuel. Most of these reactors could in principle be converted to use uranium of lower enrichment, subject in some cases to the successful development and demonstration of new fuel materials and/or fuel element designs. It is, however, generally accepted as desirable that existing fuel element geometry be retained unaltered to minimise the capital costs and licensing difficulties associated with enrichment conversion. The high flux Australian reactor, HIFAR, at Lucas Heights, Sydney is one of 5 Dido-class reactors in the above group. It operates at 10 MW using 80% 235 U HEU fuel. Theoretical studies of neutronic, thermohydraulic and operational aspects of converting HIFAR to use fuels of reduced enrichment have been made over a period. It is concluded that with no change of fuel element geometry and no penalty in the present HEU fuel cycle burn-up performance, conversion to MEU (nominally 45% 235 U) would be feasible within the limits of current fully qualified U-Al fuel materials technology. There would be no significant, adverse effects on safety-related parameters (e.g. reactivity coefficients) and only small penalties in reactor flux. Conversion to LEU (nominally 20% 235 U) a similar basis would require that fuel materials of about 2.3 g U cm -3 be fully qualified, and would depress the in-core thermal neutron flux by about 15 per cent relative to HEU fuelling. In qualitative terms, similar conclusions would be expected to hold for a majority of the above heavy water moderated reactors. (author)

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

    International Nuclear Information System (INIS)

    Mohapatra, C.; Prasada Rao, G.

    2002-01-01

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

  6. 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

  7. Study of the pyritized surfaces of the carbon steel components in heavy water production facilities

    International Nuclear Information System (INIS)

    Radulescu, Maria; Parvan, Ioana; Lucan, Dumitra; Fulger, Manuela; Dinu, Alice; Blanatui, A.

    1998-01-01

    The components used in the Girldler Sulfide (GS) process of heavy water production are made of carbon steel covered by iron sulfide layers of different compositions (mackinawite, troilite, pyrrhotite or pyrite) of variable thicknesses. The most protective layers which provide an acceptable corrosion resistance of the subjacent metal are the mixtures of pyrrhotite and pyrite. In the present work, the corrosion resistance of carbon steel samples covered by different types of sulfides was investigated by the following methods: X ray diffraction, metallography and electrochemical methods (potential-dynamical and electrochemical impedance). In order to carry out the electrochemical measurements in the same conditions as those of the operation of carbon steel components in D 2 O production facilities, the experiments were performed with Na 2 S solutions, at pH=4 - 13 and S 2- concentration value between 1 and 1000 mg/l. The dependence of corrosion rate kinetics on pH and S 2- concentration of the testing solution was investigated for sulfide covered samples comparatively with the uncovered ones. Corrosion rates determined gravimetrically were compared with those determined by electrochemical measurements. The uniformity and thickness of the sulfide layers were checked by metallographic methods. The composition of the sulfides formed in various environment conditions was established by X-ray diffraction. Reaction mechanisms specific for sulfide formation environments have been proposed. (authors)

  8. 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.

  9. On the efficiency calibration of Si(Li) detector in the low-energy region using thick-target bremsstrahlung

    Energy Technology Data Exchange (ETDEWEB)

    An, Z. E-mail: anzhu@scu.edu.cn; Liu, M.T

    2002-10-01

    In this paper, the efficiency calibration of a Si(Li) detector in the low-energy region down to 0.58 keV has been performed using thick-carbon-target bremsstrahlung by 19 keV electron impact. The shape of the efficiency calibration curve was determined from the thick-carbon-target bremsstrahlung spectrum, and the absolute value for the efficiency calibration was obtained from the use of {sup 241}Am radioactive standard source. The modified Wentzel's formula for thick-target bremsstrahlung was employed and it was also compared with the most recently developed theoretical model based upon the doubly differential cross-sections for bremsstrahlung of Kissel, Quarles and Pratt. In the present calculation of theoretical bremsstrahlung, the self-absorption correction and the convolution of detector's response function with the bremsstrahlung spectrum have simultaneously been taken into account. The accuracy for the efficiency calibration in the low-energy region with the method described here was estimated to be about 6%. Moreover, the self-absorption correction calculation based upon the prescription of Wolters et al. has also been presented as an analytical factor with the accuracy of {approx}1%.

  10. 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.

  11. 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...

  12. 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)

  13. 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

  14. Fast neutron distributions from Be and C thick targets bombarded with 80 and 160 MeV deuterons

    International Nuclear Information System (INIS)

    Pauwels, N.; Laurent, H.; Clapier, F.; Brandenburg, S.; Beijers, J. P .M.; Zegers, R. G. T.; Lebreton, H.; Saint-Laurent, M.G.; Mirea, M.

    2001-01-01

    Production of fast neutron studies have come to the fore in the past few years because of the great interest for the possible applications of induced fission to produce neutron rich ion beams. In this context, the main objective of the SPIRAL II (Systeme de Production d'Ions Radioactifs Acceleres en Ligne) and PARRNe (Production d'Atomes Radioactifs Riches en Neutrons) R and D projects is the investigation of the feasibility and of the optimum parameters for a neutron rich isotope source. Special attention is dedicated to the energy and angular distributions of the neutrons obtained through deuteron break--up in different types of converters and different incident energies. Analysis and modelling of such behaviors, together with the study of the yields of neutron induced fission, can be used to optimize the productivity of the fissioning target its geometry and designing it accordingly. The present report continues our previous studies realised for 17, 20, 28 and 200 MeV deuteron energies and it is focused on deuteron incident energies of 80 and 160 MeV. In the experiment, the double differential cross section for neutron production induced by 80 and 160 MeV deuterons impinging on thick C and Be targets, in which the incident deuterons were complete stopped, have been measured. The energy of the neutrons was determined from the time--of--flight (TOF) measurement. To obtain an energy resolution of about 4% for the fastest, forward--emitted neutrons, which have approximately beam velocity, the length of the flightpath for the detectors at angles up to 30 angle was chosen to be 6 m. At backward angles, where the neutron energies are lower, a shorter flightpath was chosen. A schematic drawing of the setup is shown. A 100 mm thick Be target and a 70 mm thick C target were used. Results are exemplified with the angular and energy distributions of neutron obtained for Be target at 80 MeV. (authors)

  15. 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

  16. 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

  17. Measurements of secondary neutrons producted from thick targets bombarded by heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Kurosawa, T.; Nakamura, T. [Tohoku Univ., Sendai (Japan). Cyclotron and Radioisotope Center; Nakao, N.; Shibata, T.; Uwamino, Y.; Nakanishi, N.; Fukumura, A.; Kumamoto, Y.

    1997-03-01

    We measured neutron angular and energy distributions from high energy heavy ions stopping in targets of carbon, aluminum, copper and lead at HIMAC. These spectra are much harder for the lighter target nucleus like carbon. This means that the momentum transfer in the forward direction from heavy ion beam to lighter nuclei is much higher than that to heavier nuclei. (author)

  18. Environmental aspects of ion-induced x-ray emission by infinitely thick targets

    International Nuclear Information System (INIS)

    Van Rinsvelt, H.A.; Dunnam, F.E.; Russell, J.P.; Bolch, W.E.

    1974-01-01

    Elemental analysis through proton and alpha particle induced x-ray emission by infinitely thick samples of environmental interest was found to be feasible. A quantization technique using internal standards and the optimization of the beam energy for optimal sensitivity were investigated. The average limit of detection ranges from about 0.1 ppM for calcium to 1 ppM for strontium

  19. Accident analysis of heavy water cooled thorium breeder reactor

    International Nuclear Information System (INIS)

    Yulianti, Yanti; Su’ud, Zaki; Takaki, Naoyuki

    2015-01-01

    Thorium has lately attracted considerable attention because it is accumulating as a by-product of large scale rare earth mining. The objective of research is to analyze transient behavior of a heavy water cooled thorium breeder that is designed by Tokai University and Tokyo Institute of Technology. That is oxide fueled, PWR type reactor with heavy water as primary coolant. An example of the optimized core has relatively small moderator to fuel volume ratio (MFR) of 0.6 and the characteristics of the core are burn-up of 67 GWd/t, breeding ratio of 1.08, burn-up reactivity loss during cycles of < 0.2% dk/k, and negative coolant reactivity coefficient. One of the nuclear reactor accidents types examined here is Unprotected Transient over Power (UTOP) due to withdrawing of the control rod that result in the positive reactivity insertion so that the reactor power will increase rapidly. Another accident type is Unprotected Loss of Flow (ULOF) that caused by failure of coolant pumps. To analyze the reactor accidents, neutron distribution calculation in the nuclear reactor is the most important factor. The best expression for the neutron distribution is the Boltzmann transport equation. However, solving this equation is very difficult so that the space-time diffusion equation is commonly used. Usually, space-time diffusion equation is solved by employing a point kinetics approach. However, this approach is less accurate for a spatially heterogeneous nuclear reactor and the nuclear reactor with quite large reactivity input. Direct method is therefore used to solve space-time diffusion equation which consider spatial factor in detail during nuclear reactor accident simulation. Set of equations that obtained from full implicit finite-difference method is solved by using iterative methods. The indication of UTOP accident is decreasing macroscopic absorption cross-section that results large external reactivity, and ULOF accident is indicated by decreasing coolant flow. The

  20. Plant life management processes and practices for heavy water reactors

    International Nuclear Information System (INIS)

    Kang, K.-S.; Cleveland, J.; Clark, C.R.

    2006-01-01

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

  1. Heavy water reactors physics; Physique des reacteurs a eau lourde

    Energy Technology Data Exchange (ETDEWEB)

    Girard, Y; Lourme, P; Naudet, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    An important research programme on heavy water reactor physics has been carried out in France for quite a few years. The decision to build the EL 4 prototype and so to choose the heavy water gas cooled type has renewed the interest in this programme and at the same time given to it a more specific orientation A summary of the results gained in this field is presented in this paper. In the first part are described the experimental investigations, most of them were carried out in the criticality facility AQUILON II. The experiments are grouped in four parts - Systematic studies of lattices Buckling measurements. - Specific studies of gas-cooled lattices. - Fine structure, spectral indices measurements etc... - Measurements on lattices or samples containing Uranium of various enrichment or Plutonium. The second part is devoted to a summary of the theoretical studies. The whole results have allowed an improvement of the calculation methods, have led to a better understanding of the neutron balance in lattices, and have permitted the establishment of a set of formula to predict not only the clean fuel conditions but also the evolution of the nuclear properties with irradiation. Some specific studies on power reactor are quoted. (authors) [French] Un important programme d'etudes sur la physique des reacteurs a eau lourde est mene en France depuis assez longtemps. La decision de construire le prototype EL 4 et de s'engager ainsi dans la filiere des reacteurs a eau lourde refroidis par gaz a redonne un nouvel interet a ce programme et l'a en meme temps oriente dans une direction plus particuliere. La presente communication, rassemble les resultats des etudes faites dans ce domaine depuis la derniere conference de Geneve. Dans la premiere partie on decrit les etudes experimentales dont la plupart ont ete effectuees dans la pile d'experiences critiques Aquilon II. Les experiences sont groupees en quatre ensembles: etude systematique de reseaux (mesures de laplaciens) etudes

  2. Design of a thorium fuelled Advanced Heavy Water Reactor

    International Nuclear Information System (INIS)

    Krishnani, P.D.

    2009-01-01

    Full text: The main objective for development of Advanced Heavy Water Reactor (AHWR) is to demonstrate thorium fuel cycle technologies, along with several other advanced technologies required for next generation reactors, so that these are readily available in time for launching the third stage. The AHWR under design is a 300 MWe vertical pressure tube type thorium-based reactor cooled by boiling light water and moderated by heavy water. The fuel consists of (Th-Pu)O 2 and ( 233 ThU)O 2 pins. The fuel cluster is designed to generate maximum energy out of 233 U, which is bred in-situ from thorium and has a slightly negative void coefficient of reactivity, negative fuel temperature coefficient and negative power coefficient. For the AHWR, the well -proven pressure tube technology and online fuelling have been adopted. Core heat removal is by natural circulation of coolant during normal operation and shutdown conditions. Thus, it combines the advantages of light water reactors and PHWRs and removes the disadvantages of PHWRs. It has several passive safety systems for reactor normal operation, decay heat removal, emergency core cooling, confinement of radioactivity etc. The fuel cycle is based on the in-situ conversion of naturally available thorium into fissile 233 U in self sustaining mode. The uranium in the spent fuel will be reprocessed and recycled back into the reactor. The plutonium inventory will be kept a minimum and will come from fuel irradiated in Indian PHWRs. The 233 U required initially can come from the fast reactor programme or it can be produced by specially designing the initial core of AHWR using (Th,Pu)MOX fuel. There will be gradual transition from the initial core which will not contain any 233 U to an equilibrium core, which will have ( 233 U, Th) MOX fuel pins also in a composite cluster. The self sustenance is being achieved by a differential fuel loading of low and a relatively higher Pu in the composite clusters. The AHWR burns the

  3. Accident analysis of heavy water cooled thorium breeder reactor

    Energy Technology Data Exchange (ETDEWEB)

    Yulianti, Yanti [Department of Physics, University of Lampung Jl. Sumantri Brojonegoro No.1 Bandar Lampung, Indonesia Email: y-yanti@unila.ac.id (Indonesia); Su’ud, Zaki [Department of Physics, Bandung Institute of Technology Jl. Ganesha 10 Bandung, Indonesia Email: szaki@fi.itb.ac.id (Indonesia); Takaki, Naoyuki [Department of Nuclear Safety Engineering Cooperative Major in Nuclear Energy (Graduate School) 1-28-1 Tamazutsumi,Setagayaku, Tokyo158-8557, Japan Email: ntakaki@tcu.ac.jp (Japan)

    2015-04-16

    Thorium has lately attracted considerable attention because it is accumulating as a by-product of large scale rare earth mining. The objective of research is to analyze transient behavior of a heavy water cooled thorium breeder that is designed by Tokai University and Tokyo Institute of Technology. That is oxide fueled, PWR type reactor with heavy water as primary coolant. An example of the optimized core has relatively small moderator to fuel volume ratio (MFR) of 0.6 and the characteristics of the core are burn-up of 67 GWd/t, breeding ratio of 1.08, burn-up reactivity loss during cycles of < 0.2% dk/k, and negative coolant reactivity coefficient. One of the nuclear reactor accidents types examined here is Unprotected Transient over Power (UTOP) due to withdrawing of the control rod that result in the positive reactivity insertion so that the reactor power will increase rapidly. Another accident type is Unprotected Loss of Flow (ULOF) that caused by failure of coolant pumps. To analyze the reactor accidents, neutron distribution calculation in the nuclear reactor is the most important factor. The best expression for the neutron distribution is the Boltzmann transport equation. However, solving this equation is very difficult so that the space-time diffusion equation is commonly used. Usually, space-time diffusion equation is solved by employing a point kinetics approach. However, this approach is less accurate for a spatially heterogeneous nuclear reactor and the nuclear reactor with quite large reactivity input. Direct method is therefore used to solve space-time diffusion equation which consider spatial factor in detail during nuclear reactor accident simulation. Set of equations that obtained from full implicit finite-difference method is solved by using iterative methods. The indication of UTOP accident is decreasing macroscopic absorption cross-section that results large external reactivity, and ULOF accident is indicated by decreasing coolant flow. The

  4. Measurements of neutron spectra produced from a thick tungsten target bombarded with 5 and 15 GeV protons

    CERN Document Server

    Meigo, S; Shigyo, N; Iga, K; Iwamoto, Y; Kitsuki, H; Ishibashi, K; Maehata, K; Arima, H; Nakamo, T; Numajiri, M

    2002-01-01

    For validation of calculation codes that are employed in the design of a pulse spallation neutron source and accelerator driven system, the spectrum of neutrons produced from a thick target plays an important role. However, appropriate experimental data were scarce for incident energies higher than 0.8 GeV. In this study, the spectrum from a thick tungsten target was measured. The experiment was carried out at the pi 2 beam line of the 12-GeV proton synchrotron at KEK. The tungsten target was bombarded by 0.5- and 1.5-GeV secondary protons. The spectrum of neutrons was measured by the time-of-flight technique using organic scintillators of NE213. The calculated result with NMTC/JAM and MCNP-4A is compared with the measured data. It is found that the NMTC/JAM generally gives a good agreement with experiment. The NMTC/JAM, however, gives 50% lower neutron flux in the energy region 20~80 MeV, which is consistent with the results in a previous comparison of a lead target. For the neutrons between 20 and 80 MeV, t...

  5. Validation of MC models of spallation reactions in thin and thick targets in the GeV range

    International Nuclear Information System (INIS)

    Goldenbaum, F.; Filges, D.; Neef, R.D.; Nuenighoff, K.; Paul, N.; Schaal, H.; Sterzenbach, G.; Tietze, A.; Wohlmuther, M.; Galin, J.; Letourneau, A.; Lott, B.; Peghaire, A.; Pienkowski, L.

    2001-01-01

    In the framework of new projects of intense spallation neutron sources an extensive experimental and theoretical effort is devoted to the precise prediction and optimization of the targets and shielding in terms of reaction cross sections, hadronic interaction lengths and usable neutrons produced in proton induced spallation reactions. Strong constraints on Monte-Carlo high energy transport codes are put by a measurement campaign of the NESSI (neutron scintillator and silicon detector) collaboration. While the predictive power of inter- and intra-nuclear cascade models coupled to evaporation codes and transport systems is excellent as far as neutron production in thick targets is concerned, there are considerable discrepancies not only between experiments and models, but also among the different codes themselves when regarding charged particle production in thin targets. In the current contribution a representative validation will be executed and possible deficiencies within the codes are elaborated. (orig.)

  6. Tritium separation from light and heavy water by bipolar electrolysis

    International Nuclear Information System (INIS)

    Ramey, D.W.; Petek, M.; Taylor, R.D.; Kobisk, E.H.; Ramey, J.; Sampson, C.A.

    1979-10-01

    Use of bipolar electrolysis with countercurrent electrolyte flow to separate hydrogen isotopes was investigated for the removal of tritium from light water effluents or from heavy water moderator. Deuterium-tritium and protium-tritium separation factors occurring on a Pd-25% Ag bipolar electrode were measured to be 2.05 to 2.16 and 11.6 to 12.4 respectively, at current densities between 0.21 and 0.50 A cm -2 , and at 35 to 90 0 C. Current densities up to 0.3 A cm -2 have been achieved in continuous operation, at 80 to 90 0 C, without significant gas formation on the bipolar electrodes. From the measured overvoltage at the bipolar electrodes and the electrolyte conductivity the power consumption per stage was calculated to be 3.0 kwh/kg H 2 O at 0.2 A cm -2 and 5.0 kwh/kg H 2 O at 0.5 A cm -2 current density, compared to 6.4 and 8.0 kwh/kg H 2 O for normal electrolysis. A mathematical model derived for hydrogen isotope separation by bipolar electrolysis, i.e., for a square cascade, accurately describes the results for protium-tritium separation in two laboratory scale, multistage experiments with countercurrent electrolyte flow; the measured tiritum concentration gradient through the cascade agreed with the calculated values

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

    International Nuclear Information System (INIS)

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

    1983-01-01

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

  8. Thorium fuels for heavy water reactors. Romanian experience

    International Nuclear Information System (INIS)

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

    1984-01-01

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

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

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  10. Benchmarking severe accident computer codes for heavy water reactor applications

    Energy Technology Data Exchange (ETDEWEB)

    Choi, J.H. [International Atomic Energy Agency, Vienna (Austria)

    2010-07-01

    Consideration of severe accidents at a nuclear power plant (NPP) is an essential component of the defence in depth approach used in nuclear safety. Severe accident analysis involves very complex physical phenomena that occur sequentially during various stages of accident progression. Computer codes are essential tools for understanding how the reactor and its containment might respond under severe accident conditions. International cooperative research programmes are established by the IAEA in areas that are of common interest to a number of Member States. These co-operative efforts are carried out through coordinated research projects (CRPs), typically 3 to 6 years in duration, and often involving experimental activities. Such CRPs allow a sharing of efforts on an international basis, foster team-building and benefit from the experience and expertise of researchers from all participating institutes. The IAEA is organizing a CRP on benchmarking severe accident computer codes for heavy water reactor (HWR) applications. The CRP scope includes defining the severe accident sequence and conducting benchmark analyses for HWRs, evaluating the capabilities of existing computer codes to predict important severe accident phenomena, and suggesting necessary code improvements and/or new experiments to reduce uncertainties. The CRP has been planned on the advice and with the support of the IAEA Nuclear Energy Department's Technical Working Groups on Advanced Technologies for HWRs. (author)

  11. Evaluation of A-1 reactor heavy-water calandria specimens

    International Nuclear Information System (INIS)

    Brumovsky, M.

    1976-01-01

    Container chains with surveillance specimens were placed in two special channels of the core peripheral part to test changes in mechanical properties due to reactor operation of caisson tube material. The specimens were made from the caisson tube material and placed by eight pieces on the outer surface of the containers. The first removed specimens were tested for corrosion losses, tensile strength, and fractured surfaces were then assessed. The changes in strength properties were found to be similar in both base material and welded joints. The corrosion film on surveillance specimens did not practically affect strength properties nor ductility. It was found that the Al-Mg-Si alloy used for the heavy water vessel caisson tubes following stabilization annealing was fully stable at operating temperatures of up to 100 degC. Slio.ht changes in properties can be attributed to the effect of a high neutron dose. Thus, the high radiation and temperature stability of the alloy was confirmed. (O.K.)

  12. Simple method of measuring pulmonary extravascular water using heavy water

    Energy Technology Data Exchange (ETDEWEB)

    Basset, G; Moreau, F; Scaringella, M; Tistchenko, S; Botter, F; Marsac, J

    1975-11-20

    The field of application of the multiple indicators dilution method in human pathology, already used to study pulmonary edema, can be extended to cover the identification and testing of all conditions leading to increase lung water. To be really practical it must be simple, fast, sensitive, inexpensive and subject to repetition; the use of non-radioactive tracers is implied. Indocyanine Green and heavy water were chosen respectively as vascular and diffusible indicators. Original methods have been developed for the treatment and isotopic analysis of blood: mass spectrometric analysis of aqueous blood extracts after deproteinisation by zinc sulphate then rapid distillation of the supernatant under helium; infrared analysis either of acetone extracts from small blood samples (100..mu..litre) or of blood itself in a continuous measurement. The infrared technique adopted has been used on rats and on men in normal and pathological situations. The results show that the method proposed for the determination of pulmonary extravascular water meets the requirements of clinicians while respecting the patients' safety, and could be generalized to other organs.

  13. 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

  14. Secondary neutron production from thick Pb target by light particle irradiation

    CERN Document Server

    Adloff, J C; Debeauvais, M; Fernández, F; Krivopustov, M; Kulakov, B A; Sosnin, A; Zamani, M

    1999-01-01

    Neutron multiplicities from spallation neutron sources were measured by Solid State Nuclear Track Detectors. Light particles as protons, deuterons and alphas in the GeV range were used on Pb targets. For neutron thermalization the targets were covered by 6 cm paraffin moderator. Neutron multiplicity distributions were studied inside and on the moderator surface. Comparison of SSNTDs results were made for thermal-epithermal neutrons with sup 1 sup 3 sup 9 La activation method as well as with Dubna DCM/CEM code. Discussion including previous sup 1 sup 2 C results are given.

  15. 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.

  16. Bioresorbable scaffold -fourth revolution or failed revolution: Is low scaffold strut thickness the wrong target?

    Directory of Open Access Journals (Sweden)

    Sundeep Mishra

    2017-11-01

    Full Text Available Bioresorbable scaffold (BRS technology has currently fallen into disrepute because of inordinately high risk of scaffold thrombosis and post-procedure myocardial infarction. Low tensile and radial strengths of polymeric BRS contributing to improper strut embedment have been identified as major correlates of poor outcomes following BRS implantation. Magnesium has a better tensile/radial strength compared with polymeric BRS but it is still far lower than cobalt-chromium. Newers innovations utilizing alteration in polymer composition and orientation or even newer polymers have focused on attempts to reduce strut thickness but may have little effect on tensile/radial strength of finished product and therefore may not impact the BRS outcome on long run. Currently, newer generation BRS usage may be restricted to suitable low risk younger patients with proper vessel preparation and application of technique.

  17. Bioresorbable scaffold -fourth revolution or failed revolution: Is low scaffold strut thickness the wrong target?

    Science.gov (United States)

    Mishra, Sundeep

    Bioresorbable scaffold (BRS) technology has currently fallen into disrepute because of inordinately high risk of scaffold thrombosis and post-procedure myocardial infarction. Low tensile and radial strengths of polymeric BRS contributing to improper strut embedment have been identified as major correlates of poor outcomes following BRS implantation. Magnesium has a better tensile/radial strength compared with polymeric BRS but it is still far lower than cobalt-chromium. Newers innovations utilizing alteration in polymer composition and orientation or even newer polymers have focused on attempts to reduce strut thickness but may have little effect on tensile/radial strength of finished product and therefore may not impact the BRS outcome on long run. Currently, newer generation BRS usage may be restricted to suitable low risk younger patients with proper vessel preparation and application of technique. Copyright © 2017 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

  18. 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

  19. 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

  20. Angular measurement of the energy distribution of neutrons from the thick target 7Li(p,n)7Be source

    International Nuclear Information System (INIS)

    Rose, A.

    1981-11-01

    The energy spectrum of neutrons emitted from a thick lithium target bombarded by protons has been measured as a function of neutron angle of emission. The measurements were done at proton energies up to 2.8 MeV and at 30 deg. intervals in the range 0 to 120 deg. using proportional detectors with gas fillings of hydrogen and methane. A review is given of papers published on the 7 Li(p,n) 7 Be reactions at 0 deg.; where applicable, comparisons are made with the present results

  1. 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)

  2. 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.

  3. 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.)

  4. 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)

  5. 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)

  6. Future development in heavy water reactors in Canada

    International Nuclear Information System (INIS)

    Donnelly, J.; Hart, R.G.

    1982-01-01

    1982 marks the 35th anniversary of the start-up of Canada's first research and test reactor, NRX. Its first power reactor has been operating successfully for the past 20 years. With 5,000 MWe of domestic capacity installed, Canada's major CANDU (Canada Deuterium, Uranium) nuclear program has a further 9,500 MWe under construction in Canada for completion by 1990 as well as committed offshore projects in Argentina, Korea and Romania. The CANDU operating record, by any measure of performance, has been outstanding. This performance is largely due to the discipline imposed on the development, design, construction and operation by two fundamental choices: natural uranium and heavy water. The impact of these two choices on availability, fuel utilization, safety and economics is discussed. Future plans call for building on those characteristics which have made CANDU so successful. When time for change comes, current assessments indicate that it will be possible to convert to more efficient advanced fuel cycles without major changes to the basic CANDU design. Primary attention is being focussed on thorium fuel cycles to ensure an abundant and continuing supply of low cost energy for the long term. The resource savings available from these fuel cycles in expanding systems are reviewed and compared with those available from LWR's and Fast Breeders. The results clearly illustrate the versatility of the CANDU reactor. It can benefit from enrichment plants or get along without them. It can complement LWR's or compete with them. It can complement Fast Breeder Reactors or compete with them as well. In the very long term CANDU's and Fast Breeders combined offer the potential of burning all the world's uranium and all the world's thorium. (author)

  7. Thick target benchmark test for the code used in the design of high intensity proton accelerator project

    International Nuclear Information System (INIS)

    Meigo, Shin-ichiro; Harada, Masatoshi

    2003-01-01

    In the neutronics design for the JAERI and KEK Joint high intensity accelerator facilities, transport codes of NMTC/JAM, MCNPX and MARS are used. In order to confirm the predict ability for these code, it is important to compare with the experiment result. For the validation of the source term of neutron, the calculations are compared with the experimental spectrum of neutrons produced from thick target, which are carried out at LANL and KEK. As for validation of low energy incident case, the calculations are compared with experiment carried out at LANL, in which target of C, Al, Fe, and 238 U are irradiated with 256-MeV protons. By the comparison, it is found that both NMTC/JAM and MCNPX show good agreement with the experiment within by a factor of 2. MARS shows good agreement for C and Al target. MARS, however, gives rather underestimation for all targets in the neutron energy region higher than 30 MeV. For the validation high incident energy case, the codes are compared with the experiment carried out at KEK. In this experiment, W and Pb targets are bombarded with 0.5- and 1.5-GeV protons. Although slightly disagreement exists, NMTC/JAM, MCNPX and MARS are in good agreement with the experiment within by a factor of 2. (author)

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

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  9. Corrosion, inspection and other problems associated with Heat exchangers in the heavy water industry

    International Nuclear Information System (INIS)

    Twigg, R.J.

    1980-01-01

    Corrosion, fabrication and inspection problems encountered in the heavy water industry Heat exchangers are discussed. Among the problems examined are erosion/corrosion of two pass exchangers, rolling of tubes, pitting, fretting and protection for long term storage. (auth)

  10. A progress review of Ontario Hydro's nuclear generation and heavy water production programs

    International Nuclear Information System (INIS)

    Kee, F.J.; Woodhead, L.W.

    Performance and economics of CANDU reactors in service are described. Progress of commissioning, construction and planning of reactors at Pickering, Bruce, and Darlington is outlined. Heavy water production is reviewed. (E.C.B.)

  11. 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%

  12. Measurement of the heavy water level in the fuel channels of the RA reactor - Annex 11

    International Nuclear Information System (INIS)

    Nikolic, M.

    1964-01-01

    The objective of measuring the heavy water level in the reactor channels was to verify experimentally the possibilities of reactor cooling with parallel operation of heavy water pumps od 1500 rotations/min at nominal power of 6.5 MW. Measurements were done in 2 periphery and 2 central fuel channels with pumps speed 1500, 1800 and 3000 rotations/min by a contact probe with electric resistance measuring device. precision of the measurement was ±1 cm

  13. A study on the establishment of component/equipment performance criteria considering Heavy Water Reactor characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Keun Sun; Kwon, Young Chul; Lee, Min Kyu; Lee, Yun Soo [Sunmoon Univ., Asan (Korea, Republic of); Chang, Seong Hoong; Ryo, Chang Hyun [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of); Kim, Soong Pyung; Hwnag, Jung Rye; Chung, Chul Kee [Chosun Univ., Gwangju (Korea, Republic of)

    2002-03-15

    Foreign and domestic technology trends, regulatory requirements, design and researches for heavy water reactors are analyzed. Safety design guides of Canada industry and regulatory documents and consultative documents of Canada regulatory agency are reviewed. Applicability of MOST guidance 16 Revision 'guidance for technical criteria of nuclear reactor facility' is reviewed. Specific performance criteria are established for components and facilities for heavy water reactor.

  14. Uncertainty analysis of LBLOCA for Advanced Heavy Water Reactor

    International Nuclear Information System (INIS)

    Srivastava, A.; Lele, H.G.; Ghosh, A.K.; Kushwaha, H.S.

    2008-01-01

    , uncertainty analysis for the Large Break LOCA (200% Inlet Header Break) of Advanced Heavy Water Reactor (AHWR) has been carried out. The uncertainty analysis was carried out for the peak cladding temperature (PCT), based on the two different methods i.e., Wilk's method and the response surface technique. Their findings have also been compared

  15. 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)

  16. 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

  17. 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

  18. 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)

  19. Systematic analysis of neutron yields from thick targets bombarded by heavy ions and protons with moving source model

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Takashi; Kurosawa, Tadahiro; Nakamura, Takashi E-mail: nakamura@cyric.tohoku.ac.jp

    2002-03-21

    A simple phenomenological analysis using the moving source model has been performed on the neutron energy spectra produced by bombarding thick targets with high energy heavy ions which have been systematically measured at the Heavy-Ion Medical Accelerator (HIMAC) facility (located in Chiba, Japan) of the National Institute of Radiological Sciences (NIRS). For the bombardment of both heavy ions and protons in the energy region of 100-500 MeV per nucleon, the moving source model incorporating the knock-on process could be generally successful in reproducing the measured neutron spectra within a factor of two margin of accuracy. This phenomenological analytical equation is expressed having several parameters as functions of atomic number Z{sub p}, mass number A{sub p}, energy per nucleon E{sub p} for projectile, and atomic number Z{sub T}, mass number A{sub T} for target. By inputting these basic data for projectile and target into this equation we can easily estimate the secondary neutron energy spectra at an emission angle of 0-90 deg. for bombardment with heavy ions and protons in the aforementioned energy region. This method will be quite useful to estimate the neutron source term in the neutron shielding design of high energy proton and heavy ion accelerators.

  20. Comparison of (alpha, n) thick-target neutron yields and spectra from ORIGEN-S and SOURCES

    International Nuclear Information System (INIS)

    Brown, T.H.; Wilson, W.B.; Perry, R.T.; Charlton, W.S.

    1998-01-01

    Both ORIGEN-S and SOURCES generate thick-target neutron yields and energy spectra from (α,n) reactions in homogeneous materials. SOURCES calculates yield and spectra for any material containing α-emitting and (α,n) target elements by simulating reaction physics, using α-emission energy spectra, elemental stopping cross sections, (α,n) cross sections for target nuclei, and branching fractions to produce-nuclide energy levels. This methodology results in accurate yield and spectra. ORIGEN-S has two options for calculating yields and spectra. The UO 2 option (default) estimates yields and spectra assuming the input α-emitters to be infinitely dilute in UO 2 . The borosilicate-glass option estimates yields from the total input material composition and generates spectra purportedly representative of spectra generated by 238 Pu, 241 Am, 242 Cm, and 244 Cm infinitely dilute in borosilicate glass, even if none of these four α-emitters are present in the input material composition. Because yields from the borosilicate-glass option in ORIGEN-S are based on entire input material composition and are reasonably accurate, the same is often assumed to be true for spectra. The input/output functionality of the borosilicate-glass option, along with ambiguity in ORIGEN-S documentation, gives the incorrect impression that spectra representative of input compositions are generated. This impression is reinforced by wide usage of the SCALE code system and its ORIGEN-S module and their sponsorship by the US Nuclear Regulatory Commission

  1. Particle-induced X-ray emission: thick-target analysis of inorganic materials in the determination of light elements

    International Nuclear Information System (INIS)

    Perez-Arantegui, J.; Castillo, J.R.; Querre, G.

    1994-01-01

    Particle-induced X-ray emission (PIXE) has been applied to the analysis of inorganic materials to determine some elements with Z < 27: Na, Mg, Al, Si, K, Ca, Ti, Mn and Fe, in thick-target analysis. A PIXE method has been developed for the analysis of geological materials, ceramics and pottery. Work has been carried out with an ion beam analytical system, using a low particle beam energy. Relative sensitivity, detection limits, reproducibility and accuracy of the method were calculated based on the analysis of geological standard materials (river sediments, argillaceous limestone, basalt, diorite and granite). Analysis using PIXE offers a number of advantages, such as short analysis time, multi-elemental and nondestructive determinations, and the results are similar to those obtained with other instrumental techniques of analysis. (Author)

  2. Increased sensitivity in thick-target particle induced X-ray emission analyses using dry ashing for preconcentration

    International Nuclear Information System (INIS)

    Lill, J.-O.; Harju, L.; Saarela, K.-E.; Lindroos, A.; Heselius, S.-J.

    1999-01-01

    The sensitivity in thick-target particle induced X-ray emission (PIXE) analyses of biological materials can be enhanced by dry ashing. The gain depends mainly on the mass reduction factor and the composition of the residual ash. The enhancement factor was 7 for the certified reference material Pine Needles and the limits of detection (LODs) were below 0.2 μg/g for Zn, Cu, Rb and Sr. When ashing biological materials with low ash contents such as wood of pine or spruce (0.3% of dry weight) and honey (0.1% of wet weight) the gain was far greater. The LODs for these materials were 30 ng/g for wood and below 10 ng/g for honey. In addition, the ashed samples were more homogenous and more resistant to changes during the irradiation than the original biological samples. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  3. Construction management of Indian pressurized heavy water reactors

    International Nuclear Information System (INIS)

    Bohra, S.A.; Sharma, P.D.

    2006-01-01

    Pandit Jawaharlal Nehru and Dr. Homi J. Bhabha, the visionary architects of Science and Technology of modern India foresaw the imperative need to establish a firm base for indigenous research and development in the field of nuclear electricity generation. The initial phase has primarily focused on the technology development in a systematic and structured manner, which has resulted in establishment of strong engineering, manufacturing and construction base. The nuclear power program started with the setting up of two units of boiling light water type reactors in 1969 for speedy establishment of nuclear technology, safety culture, and development of operation and maintenance manpower. The main aim at that stage was to demonstrate (to ourselves, and indeed to the rest of the world) that India, inspite of being a developing country, with limited industrial infrastructure and low capacity power grids, could successfully assimilate the high technology involved in the safe and economical operation of nuclear power reactors. The selection of a BWR was in contrast to the pressurized heavy water reactors (PHWR), which was identified as the flagship for the first stage of India's nuclear power program. The long-term program in three stages utilizes large reserves of thorium in the monazite sands of Kerala beaches in the third stage with first stage comprising of series of PHWR type plants with a base of 10,000 MW. India has at present 14 reactors in operation 12 of these being of PHWR type. The performance of operating units of 2720 MW has improved significantly with an overall capacity factor of about 90% in recent times. The construction work on eight reactor units with installed capacity of 3960 MW (two PHWRs of 540 MW each, four PHWRs of 220 MW each and two VVERs of 1000 MW each) is proceeding on a rapid pace with project schedules of less than 5 years from first pour of concrete. This is being achieved through advanced construction technology and management. Present

  4. Mathematical model for safety analysis of heavy water power reactor

    International Nuclear Information System (INIS)

    Milovanovic, M.; Humo, E.; Mitrovic, S.

    1966-01-01

    Fundamental information in formulating the mathematical model for accident analysis is concerned with reactivity changes of the system. These parameters are: changes of fuel and moderator temperature, changes of the upper reflector thickness, reactivity changes due to moderator density variation dependent on the steam quantity and neutron flux distribution in the core

  5. 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

  6. 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

  7. Salvaging of service exposed cast alloy 625 cracker tubes of ammonia based Heavy Water Plants

    International Nuclear Information System (INIS)

    Kumar, Niraj; Misra, B.; Mahajan, M.P.; Mittra, J.; Sundararaman, M.; Chakravartty, J.K.

    2006-01-01

    In ammonia based heavy water plants, cracking of ammonia vapour, enriched in deuterium is carried out inside a cracker tube, packed with catalyst. These cracker tubes are made of alloy 625 (either wrought or cast) having dimensions of about 12.5 metres long, 88 mm outer diameter and 7.9 mm wall thickness. Seventy such tubes are housed in a typical ammonia cracker unit. The anticipated design life of such tube is 1,00,000 hrs. when operated at 720 degC based on creep as main degradation mechanism. Presently, these tubes are being operated at 680 degC skin temperature. Alloy 625 tubes are costly and normally not manufactured in India and are being imported. The cast alloy 625 cracker tubes have outlived their design life of 100,000 hrs. Therefore it has been decided to salvage the cast cracker tubes and extend the life further as it had already been done for wrought tubes. Similar to the earlier attempt of resolutionising of wrought alloy 625 tubes, efforts are in progress to salvage these cast tubes. In this study, cast tubes samples were subjected to solution-annealing treatment at two different temperatures, 1100degC and 1160degC respectively for two hrs. Mechanical properties along with the microstructure of the samples, which were resolutionized at 1160degC were comparable with that of virgin material. The 12.5 metres long cast alloy 625 cracker tubes will also be shortly solution-annealed in a specially designed resistance heating furnace after completing some more tests. (author)

  8. Precise measurements of the thick target neutron yields of the {sup 7}Li(p,n) reaction

    Energy Technology Data Exchange (ETDEWEB)

    Matysiak, W., E-mail: matysiw@mcmaster.ca [Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ont., L8S 4K1 (Canada); Prestwich, W.V.; Byun, S.H. [Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ont., L8S 4K1 (Canada)

    2011-07-01

    Thick target neutron yield of the {sup 7}Li(p,n){sup 7}Be reaction was measured in the proton energy range from 1.95 to 2.3 MeV by determining induced activity of the {sup 7}Be. A HPGe detector was used to detect the 478 keV gamma-rays emitted through {sup 7}Be decay. A series of irradiations with nominal proton energies of 1.95, 2.0, 2.1, 2.2, and 2.3 MeV were carried out. In an independent experiment, raw neutron spectra were collected by a {sup 3}He ion chamber for the same series of proton energies. From the raw neutron spectra, it was noted, that the effective proton energies were lower than the nominal by 50-58 keV. After corrections for the proton energy offsets were applied, the measured neutron yields matched the analytically calculated yields within 20%. Long term stability of neutron yield was tested at two nominal proton energies, 2.1 and 1.95 MeV over an experimental period of one year. The results show that the yield at 2.1 MeV was stable within rmse variation coefficient of 4.7% and remained consistent even when the lithium target was replaced, whereas at 1.95 MeV, the maximum fluctuations reached a factor of 10.

  9. 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.

  10. 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.

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

    International Nuclear Information System (INIS)

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

    1989-04-01

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

  12. 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

  13. 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.

  14. Contribution of Heavy Water Board in nuclear fuel cycle technologies. Contributed Paper IT-03

    International Nuclear Information System (INIS)

    Mohanty, P.R.

    2014-01-01

    The three stage Indian nuclear power programme envisages use of closed nuclear fuel cycle and thorium utilization as its mainstay for long term energy security on sustainable basis. India is committed to realize this objective through the development and deployment of frontier technologies pertaining to all aspects of a closed nuclear fuel cycle. Comprehensive indigenous capabilities have been developed in all aspects of nuclear power and associated fuel cycles. Heavy Water Board (HWB), with its abiding objective of fulfilling demand of heavy water for India's flourishing nuclear power program, is one of the frontrunner in Nuclear Fuel Cycle Technology. HWB is now engaged in wide spectrum of activities in various facets of fuel cycle covering all the three stages of Indian Nuclear Power Programme. HWB is contributing to Nuclear Fuel Cycle through large scale production and sustained supply of key input materials including heavy water, solvents for nuclear hydrometallurgy, 10 B enriched boron etc

  15. 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.

  16. 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)

  17. Modeling the transport of hydrogen in the primary coolant of pressurized heavy water reactors

    International Nuclear Information System (INIS)

    Subramanian, H.; Velmurugan, S.; Narasimhan, S.V.; Jain, A.K.; Dash, S.C.

    2008-01-01

    Heavy water (D 2 O) is used in primary heat transport systems of PHWRs. To suppress the radiolysis of heavy water and to control oxygen, hydrogen is added at regular intervals to the primary heat transport system. The added hydrogen finds it way to the heavy water storage tank after passing through the bleed condenser. Owing to the different temperatures and two phase region present in these systems, hydrogen gets redistributed. It is important to know the concentration of dissolved hydrogen in these regions in order to ensure a steady state dissolved hydrogen concentration in the primary system. Different power stations report variations in the frequency and quantity of hydrogen added to achieve the prescribed steady state level. This paper makes an attempt to account for the inventory of hydrogen and model its transport in PHT system. (author)

  18. 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

  19. 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

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

    International Nuclear Information System (INIS)

    Guzman R, G.H.

    1980-01-01

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

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

    International Nuclear Information System (INIS)

    1977-06-01

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

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

    International Nuclear Information System (INIS)

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

    1995-01-01

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

  3. 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)

  4. 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

  5. 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

  6. Analysis of Removal Alternatives for the Heavy Water Components Test Reactor at the Savannah River Site

    International Nuclear Information System (INIS)

    Owen, M.B.

    1996-08-01

    This engineering study was developed to evaluate different options for decommissioning of the Heavy Water Components Test Reactor (HWCTR) at the Savannah River Site. This document will be placed in the DOE-SRS Area reading rooms for a period of 30 days in order to obtain public input to plans for the demolition of HWCTR

  7. Study of thermal neutron currents near cylindrical absorbers located in heavy water

    International Nuclear Information System (INIS)

    Simard, Y.N.

    1973-01-01

    The experiments reported involved determining the angular response of detectors to neutrons exterior to the surface of long cylindrical absorbers immersed in a scattering medium. The absorbers consisted of solid cylinders of copper, cadmium, or natural uranium in a fuel lattice, and combinations of copper and cadmium, as well as voided cylinders. The scattering (moderating) medium consisted of heavy water. (author)

  8. Recommended Ideal-Gas Thermochemical Functions for Heavy Water and its Substituent Isotopologues

    Czech Academy of Sciences Publication Activity Database

    Simkó, I.; Furtenbacher, T.; Hrubý, Jan; Zobov, N. F.; Polyansky, O. L.; Tennyson, J.; Gamache, R. R.; Szidarovszky, T.; Dénes, N.; Császár, A. G.

    2017-01-01

    Roč. 46, č. 2 (2017), č. článku 023104. ISSN 0047-2689 R&D Projects: GA ČR GA16-02647S Institutional support: RVO:61388998 Keywords : heavy water * ideal-gas thermochemical functions * partition function Subject RIV: BJ - Thermodynamics OBOR OECD: Thermodynamics Impact factor: 4.204, year: 2016

  9. Centrifuge experiments for removal of aluminium turbidity from Dhruva heavy water

    International Nuclear Information System (INIS)

    Shetiya, R.S.; Unny, V.K.P.; Nayak, A.P.

    1989-01-01

    Aluminium turbidity and associated radioactivity was observed in the moderator cum coolant system of Dhruva during initial power operation. Ion exchange resin beds of the purification system were not able to remove aluminium turbidity and radioactivity of system heavy water. Centrifuge technique was used as a convenient alternative method to remove the turbidity and radioactivity. (author)

  10. 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

  11. Decontamination and recycle of zirconium pressure tubes from Pressurized Heavy Water Reactor

    International Nuclear Information System (INIS)

    Gantayet, L.M.; Verma, R.; Remya Devi, P.S.; Banerjee, S.; Kotak, V.; Raha, A.; Sandeep, K.C.; Joshi, Shreeram W.; Lali, A.M.

    2009-01-01

    An ion exchange process has been developed for decontamination of zirconium pressure tubes from Pressurized Heavy Water Reactor and recycling of neutronically improved zirconium. Distribution coefficient, equilibrium isotherm, kinetic and breakthrough data were used to develop the separation process. Effect of gamma radiation on indigenous resins was also studied to assess their suitability in high radiation field. (author)

  12. 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)

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

    International Nuclear Information System (INIS)

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

    1995-01-01

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

  14. Calculations on heavy-water moderated and cooled natural uranium fuelled power reactors

    International Nuclear Information System (INIS)

    Pinedo V, J.L.

    1979-01-01

    One of the codes that the Instituto Nacional de Investigaciones Nucleares (Mexico) has for the nuclear reactors design calculations is the LEOPARD code. This work studies the reliability of this code in reactors design calculations which component materials are the same of the heavy water moderated and cooled, natural uranium fuelled power reactors. (author)

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

    International Nuclear Information System (INIS)

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

    1979-01-01

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

  16. Experimental determination of lattice parameters for 2% enriched uranium heavy water reactor cores

    Energy Technology Data Exchange (ETDEWEB)

    Raisic, N; Takac, S; Markovic, H; Bosevski, T [Boris Kidric Institute of Nuclear Sciences Vinca, Belgrade (Yugoslavia)

    1963-04-15

    Systematic measurements of the buckling, infinite multiplication factor and the thermal utilization factor were made on a series of lattices for 2% enriched uranium tubular fuel elements in heavy water. This work represents the first phase of experimental verification of standard theoretical methods used for the determination of reactor parameters.

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

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  18. 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)

  19. 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

  20. 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

  1. 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)

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

    International Nuclear Information System (INIS)

    Sonde, R.R.

    2002-01-01

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

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

    International Nuclear Information System (INIS)

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

    1989-04-01

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

  4. Comparison on the production of radionuclides in 1.4 GeV proton irradiated LBE targets of different thickness

    CERN Document Server

    Maiti, Moumita; Mendonça, Tania M; Stora, Thierry; Lahiri, Susanta

    2014-01-01

    This is the first report on the inventory of radionuclides produced in 1.4 GeV proton induced reaction on Lead-Bismuth Eutectic (LBE) targets. LBE targets of 6 mm diameter and 1 to 8 mm lengths were irradiated with 1.4 GeV protons. The radionuclides ranging from Be-7 (53.12 days) to Po-207 (5.8 h) were identified in the samples with the help of time resolved gamma-ray spectroscopy. However, there is no signature of formation of At radioisotopes, which can be produced by the interaction of secondary particles, typical for thick targets.

  5. Thick-target neutron, gamma-ray, and radionuclide production for protons below 12 MeV on nickel and carbon beam-stops

    International Nuclear Information System (INIS)

    Chadwick, M.B.; Young, P.G.; Wilson, W.B.

    1998-03-01

    Nuclear model calculations using the GNASH code are described for protons below 12 MeV incident on nickel and carbon isotopes, for beam stop design in the Los Alamos Accelerator Production of Tritium Low Energy Demonstration Accelerator (LEDA) project. The GNASH calculations apply Hauser-Feshbach and preequilibrium reaction theories and can make use of pre-calculated direct reaction cross sections to low-lying residual nucleus states. From calculated thin target cross sections, thick target 6.7 MeV and 12 MeV proton-induced production of neutrons, gamma rays, and radionuclides are determined. Emission spectra of the secondary neutrons and gamma rays are also determined. The model calculations are validated through comparisons with experimental thin- and thick-target measurements. The results of this work are being utilized as source terms in MCNP analyses for LEDA

  6. Experimental study on neutronics in bombardment of thick targets by high energy proton beams for accelerator-driven sub-critical system

    CERN Document Server

    Guo Shi Lun; Shi Yong Qian; Shen Qing Biao; Wan Jun Sheng; Brandt, R; Vater, P; Kulakov, B A; Krivopustov, M I; Sosnin, A N

    2002-01-01

    The experimental study on neutronics in the target region of accelerator-driven sub-critical system is carried out by using the high energy accelerator in Joint Institute for Nuclear Research, Dubna, Russia. The experiments with targets U(Pb), Pb and Hg bombarded by 0.533, 1.0, 3.7 and 7.4 GeV proton beams show that the neutron yield ratio of U(Pb) to Hg and Pb to Hg targets is (2.10 +- 0.10) and (1.76 +- 0.33), respectively. Hg target is disadvantageous to U(Pb) and Pb targets to get more neutrons. Neutron yield drops along 20 cm thick targets as the thickness penetrated by protons increases. The lower the energy of protons, the steeper the neutron yield drops. In order to get more uniform field of neutrons in the targets, the energy of protons from accelerators should not be lower than 1 GeV. The spectra of secondary neutrons produced by different energies of protons are similar, but the proportion of neutrons with higher energy gradually increases as the proton energy increases

  7. Observation of material, thickness, and bremsstrahlung x-ray intensity dependent effects in moderate and high Z targets in a gamma and x-ray LIDAR experiment

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiaodong, E-mail: xzhang39@utk.edu [Department of Nuclear Engineering, University of Tennessee, TN 37996 (United States); Ayaz-Maierhafer, Birsen; Laubach, Mitchell A. [Department of Nuclear Engineering, University of Tennessee, TN 37996 (United States); Hayward, Jason P. [Department of Nuclear Engineering, University of Tennessee, TN 37996 (United States); Oak Ridge National Lab, Oak Ridge, TN 37831 (United States)

    2015-06-01

    A high energy gamma and x-ray LIDAR system consisting of a fast pulse (~50 ps, FWHM) LINAC and a Cherenkov detection system was used to investigate response differences among materials, their thicknesses, and bremsstrahlung x-ray intensities. The energies and pulse width of electrons used to produce bremsstrahlung x-rays were set at 20 or 40 MeV and 50 ps FWHM duration, respectively. The Cherenkov detector was built with a fused silica glass optically coupled to a 51 mm fast timing photomultiplier tube, which has an intrinsic energy threshold of 340.7 keV for Compton backscattered gammas. Such a fast detection system yields a coincidence resolving time of 93 ps FWHM, which is equivalent to a depth resolving capability of about 3 cm FWHM. The thicknesses of iron and lead targets were varied from 1 in. to 7 in. with a step of 1 in., and the thicknesses of DU were varied from 1/3 in. to 1 in. with a step of 1/3 in. The experimental results show that iron targets tend to produce a factor of five less observed x-rays and gammas, with less energetic photoelectron frequency distributions, compared with DU and lead targets for the same beam intensity and target thicknesses. Additionally, the self-shielding effect causes the lead to yield more gammas than the DU considering the experimental observation point. For the setup used in this study, a charge per pulse in the range of 1–2.5 nC yields the best resolving capability between the DU and lead targets.

  8. The time resolved SBS and SRS research in heavy water and its application in CARS

    Science.gov (United States)

    Liu, Jinbo; Gai, Baodong; Yuan, Hong; Sun, Jianfeng; Zhou, Xin; Liu, Di; Xia, Xusheng; Wang, Pengyuan; Hu, Shu; Chen, Ying; Guo, Jingwei; Jin, Yuqi; Sang, Fengting

    2018-05-01

    We present the time-resolved character of stimulated Brillouin scattering (SBS) and backward stimulated Raman scattering (BSRS) in heavy water and its application in Coherent Anti-Stokes Raman Scattering (CARS) technique. A nanosecond laser from a frequency-doubled Nd: YAG laser is introduced into a heavy water cell, to generate SBS and BSRS beams. The SBS and BSRS beams are collinear, and their time resolved characters are studied by a streak camera, experiment show that they are ideal source for an alignment-free CARS system, and the time resolved property of SBS and BSRS beams could affect the CARS efficiency significantly. By inserting a Dye cuvette to the collinear beams, the time-overlapping of SBS and BSRS could be improved, and finally the CARS efficiency is increased, even though the SBS energy is decreased. Possible methods to improve the efficiency of this CARS system are discussed too.

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

    International Nuclear Information System (INIS)

    Baynes, C.J.

    1986-05-01

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

  10. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1989-04-01

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

  12. 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.

  13. Improvements in heavy water analysis using a ratio recording infrared spectrophotometer (Preprint No. CA-12)

    Energy Technology Data Exchange (ETDEWEB)

    Sutawane, U B; Alphonse, K P; Rathi, B N [Bhabha Atomic Research Centre, Bombay (India). Heavy Water Div.

    1989-04-01

    With a view to optimise existing analytical procedures for routine analyses of heavy water, studies were carried out using a ratio recording instrument with and without a reference beam attenuator in infrared spectrophotometric method. Absorbance difference as well as absorbance values with different path length cells were used for measurements. Due to various practical considerations, a method based on measurement of absorbance values rather than absorbance difference was found to be convenient for all routine work. However, scanning is essential since there is slight shifting of peak position. Measurements at fixed wave lengths should generally be avoided. Use of standards for calibration of instrument is essential and frequent check of calibration is recommended. Optimum conditions for analysis of heavy water in different ranges on the instrument used in this study are tabulated. (author). 6 refs., 1 tab.

  14. Improvements in heavy water analysis using a ratio recording infrared spectrophotometer (Preprint No. CA-12)

    International Nuclear Information System (INIS)

    Sutawane, U.B.; Alphonse, K.P.; Rathi, B.N.

    1989-04-01

    With a view to optimise existing analytical procedures for routine analyses of heavy water, studies were carried out using a ratio recording instrument with and without a reference beam attenuator in infrared spectrophotometric method. Absorbance difference as well as absorbance values with different path length cells were used for measurements. Due to various practical considerations, a method based on measurement of absorbance values rather than absorbance difference was found to be convenient for all routine work. However, scanning is essential since there is slight shifting of peak position. Measurements at fixed wave lengths should generally be avoided. Use of standards for calibration of instrument is essential and frequent check of calibration is recommended. Optimum conditions for analysis of heavy water in different ranges on the instrument used in this study are tabulated. (author). 6 refs., 1 tab

  15. 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

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

    International Nuclear Information System (INIS)

    Xu Xiaoqin; Shiroya, S.

    2002-01-01

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

  17. 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)

  18. 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.

  19. 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)

  20. 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

  1. Detection of heavy-water leaks in nuclear reactors : a novel method

    International Nuclear Information System (INIS)

    Murthy, M.S.; Gor, M.K.

    2002-01-01

    Technical Physics and Prototype Engineering Division, BARC has designed, developed and produced several high sensitivity mass spectrometer helium leak detectors over a period of two decades. Sometimes back, when there was a problem of detecting heavy water leaks in situ in one of the nuclear power reactors of the Department of Atomic Energy, it was referred to this division for a technical solution. After discussing with the site engineers, the various problems involved in the on-line detection of heavy water leaks especially near the end fittings of the coolant assemblies, a novel method of leak detection was developed. Some of the salient features of the method and the results obtained in the laboratory tests are given in this paper. (author)

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

    International Nuclear Information System (INIS)

    Robertson, R.F.S.

    1975-09-01

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

  3. 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

  4. 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)

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

    International Nuclear Information System (INIS)

    Ronen, Y.; Reyev, D.

    1983-01-01

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

  6. 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

  7. 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

  8. Comparison of methods for the determination of boron in heavy water moderator

    International Nuclear Information System (INIS)

    Green, L.W.; Davey, E.C.; Gulens, J.; Longhurst, T.H.; Mislan, J.P.

    1984-01-01

    Five analysis methods were compared for the determination of boron in heavy water moderator: isotope dilution mass spectrometry, spectrophotometry, neutron activation, inductively coupled plasma -atomic emission spectrometry, and ion selective electrode potentiometry. Ten samples were analysed by each method; the results showed close agreement between all of the methods. Only mass spectrometry achieved the required precision ( 10 B concentration must be determined, only mass spectrometry and neutron activation are applicable

  9. Neutronic calculations in heavy water moderated multiplying media using GGC-3 library nuclear data

    International Nuclear Information System (INIS)

    Boado, H.J.; Gho, C.J.; Abbate, M.J.

    1981-01-01

    Differences in obtaining transference matrices between GGC-3 code and the system to produce multigroup cross sections using GGC-3 library, recently implemented at the Neutrons and Reactors Division, have been analized. Neutronic calculations in multiplicative systems containing heavy water have been made using both methods. From the obtained results, it is concluded that the new method is more appropriate to deal with systems including moderators other than light water. (author) [es

  10. 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

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

    International Nuclear Information System (INIS)

    Delfino, C.A.

    1986-01-01

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

  12. Solution enthalpies of alkali metal halides in water and heavy water mixtures with dimethyl sulfoxide

    International Nuclear Information System (INIS)

    Egorov, G.I.

    1994-01-01

    Solution enthalpies of CsF, LiCl, NaI, CsI and some other halides of alkali metals and tetrabutylammonium have been measured by the method of calorimetry. Standard solution enthalpies of all alkali metals (except rubidium) halides in water and heavy water mixtures with dimethylsulfoxide at 298.15 K have been calculated. Isotopic effects in solvation enthalpy of the electrolytes mentioned in aqueous solutions of dimethylsulfoxide have been discussed. 29 refs., 2 figs., 4 tabs

  13. 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

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

    International Nuclear Information System (INIS)

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

    1992-01-01

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

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

    International Nuclear Information System (INIS)

    Mistry, I.L.

    1992-01-01

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

  16. Expansion connection of socket in flow distributed cabin of heavy water research reactor inner shell

    International Nuclear Information System (INIS)

    Jiang Zhiliang; Li Yanshui

    1995-01-01

    Expansion connection of aluminium alloy LT21 socket in flow distributed cabin of Heavy Water Research Reactor (HWRR) inner shell is described systematically. The expansion connection technology parameters of products are determined through tests. They are as following: bounce value of inner diameter after expansion, expansion degree, space between socket and plate hole, device for expanding pipes, selection of tools for enlarging or reaming holes, manufacture for socket inner hole and cleaning after expansion

  17. The experimental determination of the buckling in the bare heavy water natural uranium critical assembly 'RB'

    Energy Technology Data Exchange (ETDEWEB)

    Raisic, N M; Popovic, D D; Takac, S M; Djordjevic, M M [Boris Kidric Institute of Nuclear Sciences, Vinca, Beograd (Yugoslavia)

    1960-03-15

    The buckling in the bare heavy water natural uranium critical assembly was determined by measuring the thermal neutron flux distribution. The obtained value for the critical buckling at the temperature of 20 deg C is: B{sup 2} = (8.516 {+-} 0.02) m{sup -2}. The above error is a statistical one, obtained from several series of measurements. The possible systematic error was estimated as 0.1 m{sup -2}. (author)

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  19. The experimental determination of the buckling in the bare heavy water natural uranium critical assembly 'RB'

    International Nuclear Information System (INIS)

    Raisic, N.M.; Popovic, D.D.; Takac, S.M.; Djordjevic, M.M.

    1960-01-01

    The buckling in the bare heavy water natural uranium critical assembly was determined by measuring the thermal neutron flux distribution. The obtained value for the critical buckling at the temperature of 20 deg C is: B 2 = (8.516 ± 0.02) m -2 . The above error is a statistical one, obtained from several series of measurements. The possible systematic error was estimated as 0.1 m -2 . (author)

  20. Heavy water effects on the structure, functions and behavior of biological systems

    International Nuclear Information System (INIS)

    Buzgariu, Wanda; Caloianu, Maria; Moldovan, Lucia; Titescu, G.

    2003-01-01

    The H 2 O substitution for D 2 O either in environment or in the culture medium of the living systems generates changes in their main functions and composition. In this paper some of the heavy water effects in biological systems such as structural and functional changes were reviewed: normal cell architecture alterations, cell division and membrane functions disturbance, muscular contractility and the perturbations of biological oscillators such as circadian rhythm, heart rate, respiratory cycle, tidal and ultradian rhythm. (authors)

  1. 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

  2. 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

  3. 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

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

    International Nuclear Information System (INIS)

    1992-02-01

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

  5. 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.

  6. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-12-15

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

  8. 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.

  9. 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

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

    International Nuclear Information System (INIS)

    Preda, Marius Cristian

    2006-01-01

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

  11. Implications of alpha-decay for long term storage of advanced heavy water reactor fuels

    International Nuclear Information System (INIS)

    Pencer, J.; McDonald, M.H.; Roubtsov, D.; Edwards, G.W.R.

    2017-01-01

    Highlights: •Alpha decays versus storage time are calculated for examples of advanced heavy water reactor fuels. •Estimates are made for fuel swelling and helium bubble formation as a function of time. •These predictions are compared to predictions for natural uranium fuel. •Higher rates of damage are predicted for advanced heavy water reactor fuels than natural uranium. -- Abstract: The decay of actinides such as 238 Pu, results in recoil damage and helium production in spent nuclear fuels. The extent of the damage depends on storage time and spent fuel composition and has implications for the integrity of the fuels. Some advanced nuclear fuels intended for use in pressurized heavy water pressure tube reactors have high initial plutonium content and are anticipated to exhibit swelling and embrittlement, and to accumulate helium bubbles over storage times as short as hundreds of years. Calculations are performed to provide estimates of helium production and fuel swelling associated with alpha decay as a function of storage time. Significant differences are observed between predicted aging characteristics of natural uranium and the advanced fuels, including increased helium concentrations and accelerated fuel swelling in the latter. Implications of these observations for long term storage of advanced fuels are discussed.

  12. A simple thick target for production of 89Zr using an 11MeV cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Link, Jeanne M.; Krohn, Kenneth A.; O' Hara, Matthew J.

    2017-04-01

    The growing interest but limited availability of 89Zr for PET led us to test targets for the 89(p,n) reaction. The goal was an easily constructed target for an 11 MeV Siements cyclotron. Yttrium foils were tested at different thicknesses, angles and currents. A 90 degree foil tolerated 41 microAmp without damage and produced ~800 MBq/hr, >20 mCi, an amount adequate for radiochemistry research and human doses in a widely available accelerator. This method should translate to higher energy cyclotrons.

  13. Measurements of L shell X-ray yields of thick Ag target by 6–29 keV electron impact

    International Nuclear Information System (INIS)

    Zhao, J.L.; Tian, L.X.; Li, X.L.; An, Z.; Zhu, J.J.; Liu, M.T.

    2015-01-01

    In this paper, the L shell X-ray yields for a thick Ag target have been measured at incident electron energies of 6–29 keV. The experimental values are compared with the Monte Carlo simulation results that are obtained by using the PENELOPE code, in which the inner-shell ionization cross sections by electron impact calculated in the theoretical frame of distorted wave Born approximation are used. The experimental and simulation values are in agreement with ∼10% difference. Meanwhile, the L shell X-ray production cross sections are also obtained based on the measured L shell X-ray yields for a thick Ag target in this paper, and are compared with other experimental Ag L shell X-ray production cross section data by electron and positron impact measured previously and some theoretical models. Some factors that could affect these comparisons are also discussed in this paper. - Highlights: • We measured L shell X-ray yields of thick Ag target by 6–29 keV electrons. • Our measured X-ray yields are in good agreement with the MC results with ∼10%. • L shell production cross sections are obtained based on the measured X-ray yields. • L shell production cross sections obtained are in good agreement with theories

  14. 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.

  15. Angular distribution of thick-target bremsstrahlung produced by electrons with initial energies ranging from 10 to 20 keV incident on Ag

    Energy Technology Data Exchange (ETDEWEB)

    Gonzales, D.; Cavness, B.; Williams, S. [Department of Physics, Angelo State University, San Angelo, Texas 76909 (United States)

    2011-11-15

    Experimental results are presented comparing the intensities of the bremsstrahlung produced by electrons with initial energies ranging from 10 to 20 keV incident on a thick Ag target, measured at forward angles in the range of 0 degree sign to 55 degree sign . When the data are corrected for attenuation due to photon absorption within the target, the results indicate that the detected radiation is distributed anisotropically only at photon energies k that are approximately equal to the initial energy of the incident electrons E{sub 0}. The results of our experiments suggest that, as k/E{sub 0}{yields} 0, the detected radiation essentially becomes isotropic due primarily to the scattering of electrons within the target. A comparison to the theory of Kissel et al.[At. Data Nucl. Data Tables 28, 381 (1983)] suggests that the angular distribution of bremsstrahlung emitted by electrons incident on thick targets is similar to the angular distribution of bremsstrahlung emitted by electrons incident on free-atom targets only when k/E{sub 0}{approx_equal} 1. The experimental data also are in approximate agreement with the angular distribution predictions of the Monte Carlo program penelope.

  16. Monte Carlo modelling and comparison with experiment of the nuclide production in thick stony targets isotropically irradiated with 600 MeV protons

    International Nuclear Information System (INIS)

    Aylmer, D.; Herzog, G.F.; Kruse, T.H.; Cloth, P.; Filges, D.; Moniot, R.K.; Signer, P.; Wieler, R.; Tuniz, C.

    1987-05-01

    Depth profiles for the production of stable and radioactive nuclides have been measured for a large variety of target elements in three thick spherical stony targets with radii of 5, 15 and 26 cm isotropically irradiated with 600 MeV protons at the CERN synchrocyclotron. These irradiation experiments (CERN SC96) were intended to simulate the irradiation of meteoroids by galactic cosmic ray protons. In order to combine this experimental approach with a theoretical one the intra- and internuclear cascades were calculated using Monte Carlo techniques via the high energy transport code HET/KFA 1. Together with transport calculations for low energy neutrons by the MORSE-CG code the depth dependent spectra of primary and secondary protons and of secondary neutrons were derived. On the basis of these spectra and a set of evaluated experimental excitation functions for p-induced reactions and of theoretical ones for n-induced reactions, calculated by the code ALICE LIVERMORE 82, theoretical depth profiles for the production of stable and radioactive nuclides in the three thick targets were calculated. This report is a comprehensive survey on all those target/product combination for which both experimental and theoretical data are available. It provides the basis for a detailed discussion of the various production modes of residual nuclides and on the depth and size dependence of their production rates in thick stony targets, serving as a simulation of the galactic cosmic ray irradiation of meteoroids in space. On the other hand the comparison of the experimental and theoretical depth profiles validates the high energy transport calculations, making them a promissing tool for further model calculations of the interactions of cosmic rays with matter. (orig.)

  17. 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

  18. 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)

  19. Investigation of the heavy water distillation system at the RA reactor; Ispitivanje sistema za destilaciju teske vode reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

    Zecevic, V; Badrljica, R [Institute of Nuclear Sciences Boris Kidric, Reaktor RA, Vinca, Beograd (Serbia and Montenegro)

    1963-02-15

    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%.

  20. 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

  1. Measurements of neutron spectra produced from a thick tungsten target bombarded with 0.5- and 1.5-GeV protons

    International Nuclear Information System (INIS)

    Meigo, Shin-ichiro; Takada, Hiroshi

    2002-01-01

    For validation of calculation codes that are employed in the design of pulse spallation neutron source and accelerator driven system, spectrum of neutrons produced from a thick target plays an important role. However, appropriate experimental data were scarce for the incident energies higher than 0.8 GeV. In this study, the spectrum from a thick tungsten target was measured. The experiment was carried out at the π2 beam line of the 12-GeV proton synchrotron at KEK. The tungsten target was bombarded by the 0.5- and 1.5-GeV secondary protons. Spectrum of neutrons was measured by the time-of-flight technique using organic scintillators of NE213. The calculated result with NMTC/JAM and MCNP-4A is compared with the measured data. It is found that the NMTC/JAM generally gives a good agreement with experiment. The NMTC/JAM, however, gives 50% lower neutron flux in the energy region 20∼80 MeV, which is consistent with the results in previous comparison of lead target. For the neutrons between 20 and 80 MeV, the calculation using with the in-medium nucleon-nucleon cross sections reproduced the experiment fairly well. (author)

  2. Scale-up of high specific activity {sup 186g}Re production using graphite-encased thick {sup 186}W targets and demonstration of an efficient target recycling process

    Energy Technology Data Exchange (ETDEWEB)

    Balkin, Ethan R.; Gagnon, Katherine; Dorman, Eric [Washington Univ., Seattle, WA (United States). Dept. of Radiation Oncology; and others

    2017-07-01

    Production of high specific activity {sup 186g}Re is of interest for development of theranostic radiopharmaceuticals. Previous studies have shown that high specific activity {sup 186g}Re can be obtained by cyclotron irradiation of enriched {sup 186}W via the {sup 186}W(d,2n){sup 186g}Re reaction, but most irradiations were conducted at low beam currents and for short durations. In this investigation, enriched {sup 186}W metal targets were irradiated at high incident deuteron beam currents to demonstrate production rates and contaminants produced when using thick targets. Full-stopping thick targets, as determined using SRIM, were prepared by uniaxial pressing of powdered natural abundance W metal or 96.86% enriched {sup 186}W metal encased between two layers of graphite flakes for target material stabilization. An assessment of structural integrity was made on each target preparation. To assess the performance of graphite-encased thick {sup 186}W metal targets, along with the impact of encasing on the separation chemistry, targets were first irradiated using a 22 MeV deuteron beam for 10 min at 10, 20, and 27 μA, with an estimated nominal deuteron energy of 18.7 MeV on the {sup 186}W target material (after energy degradation correction from top graphite layer). Gamma-ray spectrometry was performed post EOB on all targets to assess production yields and radionuclidic byproducts. The investigation also evaluated a method to recover and recycle enriched target material from a column isolation procedure. Material composition analyses of target materials, pass-through/wash solutions and recycling process isolates were conducted with SEM, FTIR, XRD, EDS and ICP-MS spectrometry. To demonstrate scaled-up production, a graphite-encased {sup 186}W target made from recycled {sup 186}W was irradiated for ∝2 h with 18.7 MeV deuterons at a beam current of 27 μA to provide 0.90 GBq (24.3 mCi) of {sup 186g}Re, decay-corrected to the end of bombardment. ICP-MS analysis of the

  3. 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)

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

    International Nuclear Information System (INIS)

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

    2004-01-01

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

  5. Measurement of thick target neutron yield from the reaction (p+181 Ta) with projectiles in the range of 6-20 MeV

    Science.gov (United States)

    Paul, Sabyasachi; Sahoo, G. S.; Tripathy, S. P.; Sharma, S. C.; Joshi, D. S.; Bandyopadhyay, T.

    2018-02-01

    181Ta is a commonly used backing material for many targets in nuclear reaction studies. When the target thickness is less than the range of bombarded projectiles, the interaction via Ta(p,n) reactions in the backing can be a significant source of background. In this study, the neutron spectral yields from the reaction of protons of different energies (between 6 to 20 MeV) with a thick Ta target were determined using CR-39 detectors. The results from this study can be used as a correction factor in such situations. The parameters of registered tracks in CR-39 were analysed using an in-house image analysing program autoTRAK_n and then to derive the associated dose values. The spectral yields obtained experimentally were compared with those obtained from the theoretical calculations. The neutron yield was found to increase with increase in projectile energy mainly due to the opening of reaction channels from (p, n) to (p, 3n).

  6. 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)

  7. Comparison of methods for the determination of boron in heavy water moderator

    Energy Technology Data Exchange (ETDEWEB)

    Green, L.W.; Davey, E.C.; Gulens, J.; Longhurst, T.H.; Mislan, J.P. (Atomic Energy of Canada Ltd., Chalk River, Ontario. Chalk River Nuclear Labs.)

    1984-08-01

    Five analysis methods were compared for the determination of boron in heavy water moderator: isotope dilution mass spectrometry, spectrophotometry, neutron activation, inductively coupled plasma -atomic emission spectrometry, and ion selective electrode potentiometry. Ten samples were analysed by each method; the results showed close agreement between all of the methods. Only mass spectrometry achieved the required precision (<1 percent rsd) for samples taken during initial reactor operation, but all of the methods achieved sufficient precision (<10 percent rsd) for samples taken during normal operation. For samples for which the /sup 10/B concentration must be determined, only mass spectrometry and neutron activation are applicable.

  8. Absolute determination of the deuterium content of heavy water, measurement of absolute density

    International Nuclear Information System (INIS)

    Ceccaldi, M.; Riedinger, M.; Menache, M.

    1975-01-01

    The absolute density of two heavy water samples rich in deuterium (with a grade higher than 99.9%) was determined with the hydrostatic method. The exact isotopic composition of this water (hydrogen and oxygen isotopes) was very carefully studied. A theoretical estimate enabled us to get the absolute density value of isotopically pure D 2 16 O. This value was found to be 1104.750 kg.m -3 at t 68 =22.3 0 C and under the pressure of one atmosphere. (orig.) [de

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

    International Nuclear Information System (INIS)

    Archinoff, G.H.

    1979-07-01

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

  10. Removal of aluminum turbidity from heavy water reactors by precipitation ion exchange using magnesium hydroxide

    International Nuclear Information System (INIS)

    Venkateswarlu, K.S.; Shanker, R.; Velmurugan, S.; Venkateswaran, G.; Rao, M.R.

    1988-01-01

    A special magnesium hydroxide MG(OH)/sub 2/ sorber, loaded onto an ion-exchange matrix has been developed to remove hydrated alumina turbidity in heavy water. This sorber was applied to the coolant/moderator system in the research reactor Dhruva. The sorber not only removed turbidity but also suspended uranium at parts per billion levels and associated β, γ activity. The sorption is based on the attraction between the positively charged Mg(OH)/sub 2/ surface and the negatively charged hydrated alumina particles

  11. Analytical performance of refractometry in quantitative estimation of isotopic concentration of heavy water in nuclear reactor

    International Nuclear Information System (INIS)

    Dhole, K.; Ghosh, S.; Datta, A.; Tripathy, M.K.; Bose, H.; Roy, M.; Tyagi, A.K.

    2011-01-01

    The method of refractometry has been investigated for the quantitative estimation of isotopic concentration of D 2 O (heavy water) in a simulated water sample. Viability of Refractometry as an excellent analytical technique for rapid and non-invasive determination of D 2 O concentration in water samples has been demonstrated. Temperature of the samples was precisely controlled to eliminate effect of temperature fluctuation on refractive index measurement. Calibration performance by this technique exhibited reasonable analytical response over a wide range (1-100%) of D 2 O concentration. (author)

  12. Enrichment of heavy water in thermal-diffusion columns connected in series

    International Nuclear Information System (INIS)

    Yeh, Ho-Ming; Chen, Liu Yi

    2009-01-01

    The separation equations for enrichment of heavy water from water isotope mixture by thermal diffusion in multiple columns connected in series, have been derived based on one column design developed in previous work. The improvement in separation is achievable by operating in a double-column device, instead of in a single-column device, with the same total column length. It is also found that further improvement in separation is obtainable if a triple-column device is employed, except for operating under small total column length and low flow rate.

  13. Selected bibliography on heavy water, tritiated water and hydrogen isotopes (1981-1992)

    International Nuclear Information System (INIS)

    Gopalakrishnan, V.T.; Sutawane, U.B.; Rathi, B.N.

    1994-01-01

    A selected bibliography on heavy water, tritiated water and hydrogen isotopes is presented. This bibliography covers the period 1981-1992 and is in continuation to Division's earlier report BARC-1192 (1983). The sources of information for this compilation are Chemical Abstracts, INIS Atom Index and also some scattered search through journals and reports available in our library. No claim is made towards exhaustiveness of this bibliography even though sincere attempts have been made for a wide coverage. The bibliography is arranged under the headings: (1) production, purification, recovery, reprocessing and storage, (2) isotope exchange, 3) isotope analysis, (4) properties and (5) miscellaneous. Total number of references in the bibliography are 1762. (author)

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

    International Nuclear Information System (INIS)

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

    2000-01-01

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

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

    International Nuclear Information System (INIS)

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

    1992-01-01

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

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

    International Nuclear Information System (INIS)

    Lefrancois, Bernard

    1970-01-01

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

  17. New evaluation of thermal neutron scattering libraries for light and heavy water

    Directory of Open Access Journals (Sweden)

    Marquez Damian Jose Ignacio

    2017-01-01

    Full Text Available In order to improve the design and safety of thermal nuclear reactors and for verification of criticality safety conditions on systems with significant amount of fissile materials and water, it is necessary to perform high-precision neutron transport calculations and estimate uncertainties of the results. These calculations are based on neutron interaction data distributed in evaluated nuclear data libraries. To improve the evaluations of thermal scattering sub-libraries, we developed a set of thermal neutron scattering cross sections (scattering kernels for hydrogen bound in light water, and deuterium and oxygen bound in heavy water, in the ENDF-6 format from room temperature up to the critical temperatures of molecular liquids. The new evaluations were generated and processable with NJOY99 and also with NJOY-2012 with minor modifications (updates, and with the new version of NJOY-2016. The new TSL libraries are based on molecular dynamics simulations with GROMACS and recent experimental data, and result in an improvement of the calculation of single neutron scattering quantities. In this work, we discuss the importance of taking into account self-diffusion in liquids to accurately describe the neutron scattering at low neutron energies (quasi-elastic peak problem. To improve modeling of heavy water, it is important to take into account temperature-dependent static structure factors and apply Sköld approximation to the coherent inelastic components of the scattering matrix. The usage of the new set of scattering matrices and cross-sections improves the calculation of thermal critical systems moderated and/or reflected with light/heavy water obtained from the International Criticality Safety Benchmark Evaluation Project (ICSBEP handbook. For example, the use of the new thermal scattering library for heavy water, combined with the ROSFOND-2010 evaluation of the cross sections for deuterium, results in an improvement of the C/E ratio in 48 out of

  18. Non-Invasive Acoustic-Based Monitoring of Heavy Water and Uranium Process Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Pantea, Cristian [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sinha, Dipen N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lakis, Rollin Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Beedle, Christopher Craig [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Davis, Eric Sean [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-10-20

    This presentation includes slides on Project Goals; Heavy Water Production Monitoring: A New Challenge for the IAEA; Noninvasive Measurements in SFAI Cell; Large Scatter in Literature Values; Large Scatter in Literature Values; Highest Precision Sound Speed Data Available: New Standard in H/D; ~400 pts of data; Noninvasive Measurements in SFAI Cell; New funding from NA241 SGTech; Uranium Solution Monitoring: Inspired by IAEA Challenge in Kazakhstan; Non-Invasive Acoustic-Based Monitoring of Uranium in Solutions; Non-Invasive Acoustic-Based Monitoring of Uranium in Solutions; and finally a summary.

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

    International Nuclear Information System (INIS)

    1995-06-01

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

  20. Peak power and heavy water production from electrolytic H2 and O2 using CANDU reactors

    International Nuclear Information System (INIS)

    Hammerli, M.; Stevens, W.H.; Bradley, W.J.; Butler, J.P.

    1976-04-01

    A combined energy storage - heavy water production system is presented. Off-peak nuclear energy is stored in the form of electrolytic H 2 (and O 2 ) from which a large fraction of the deuterium has been transferred to water in an H 2 /H 2 O deuterium exchange catalytic column. The main features and advantages of the combined electrolysis -catalytic exchange D 2 O process are discussed. Significant quantities of D 2 O could be produced economically at reasonable peak to base power cost ratios. Thirty to forty percent of the primary electric energy should be available for peak energy via either gas-steam turbines or fuel cells. (author)

  1. Study relating to the physico-chemical behaviour of heavy water in nuclear reactors

    International Nuclear Information System (INIS)

    Chenouard, J.; Dirian, G.; Roth, E.; Vignet, P.; Platzer, R.

    1959-01-01

    Chemical and isotope pollution, and radiolytic decomposition are the two most important ways in which heavy water becomes degraded in nuclear reactors. Chemical pollution has led to the creation of ion exchange purification loops specially designed for reactors: the report contains a description in detail of the application of this purification method in CEA research reactors, including the analysis required, results obtained, and their interpretation. The intelligence obtained on radiolytic decomposition with the same facilities is also discussed, as well as the recombination apparatus and control equipment utilized. Finally, investigation to date in the CEA on recombination circuits for power reactors is also discussed. (author) [fr

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

    International Nuclear Information System (INIS)

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

    1979-01-01

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

  3. New evaluation of thermal neutron scattering libraries for light and heavy water

    Science.gov (United States)

    Marquez Damian, Jose Ignacio; Granada, Jose Rolando; Cantargi, Florencia; Roubtsov, Danila

    2017-09-01

    In order to improve the design and safety of thermal nuclear reactors and for verification of criticality safety conditions on systems with significant amount of fissile materials and water, it is necessary to perform high-precision neutron transport calculations and estimate uncertainties of the results. These calculations are based on neutron interaction data distributed in evaluated nuclear data libraries. To improve the evaluations of thermal scattering sub-libraries, we developed a set of thermal neutron scattering cross sections (scattering kernels) for hydrogen bound in light water, and deuterium and oxygen bound in heavy water, in the ENDF-6 format from room temperature up to the critical temperatures of molecular liquids. The new evaluations were generated and processable with NJOY99 and also with NJOY-2012 with minor modifications (updates), and with the new version of NJOY-2016. The new TSL libraries are based on molecular dynamics simulations with GROMACS and recent experimental data, and result in an improvement of the calculation of single neutron scattering quantities. In this work, we discuss the importance of taking into account self-diffusion in liquids to accurately describe the neutron scattering at low neutron energies (quasi-elastic peak problem). To improve modeling of heavy water, it is important to take into account temperature-dependent static structure factors and apply Sköld approximation to the coherent inelastic components of the scattering matrix. The usage of the new set of scattering matrices and cross-sections improves the calculation of thermal critical systems moderated and/or reflected with light/heavy water obtained from the International Criticality Safety Benchmark Evaluation Project (ICSBEP) handbook. For example, the use of the new thermal scattering library for heavy water, combined with the ROSFOND-2010 evaluation of the cross sections for deuterium, results in an improvement of the C/E ratio in 48 out of 65

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

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  5. Studies on corrosion inhibitors for the cooling water system at the Heavy Water Project, Kota

    International Nuclear Information System (INIS)

    Pillai, B.P.; Mehta, C.T.; Abubacker, K.M.

    1986-01-01

    The Heavy Water Project at Kota uses the water from the Rana Pratap Sagar Lake as coolant in the open recirculation system. In order to find suitable corrosion inhibitors for the above system, a series of laboratory experiments on corrosion inhibitors were carried out using the constructional materials of the cooling water system and a number of proprietary formulations and the results are tabulated. From the data thus generated through various laboratory experiments, the most useful ones have been recommended for application in practice. (author)

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

    International Nuclear Information System (INIS)

    Montes D, N.L.

    1977-01-01

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

  7. Hadron production at 0.8Mrad by 300GeV protons incident on a thick aluminium target

    International Nuclear Information System (INIS)

    Aubert, B.; Benvenuti, A.; Cline, D.; Coffin, T.; Diamond, R.; French, R.; Ford, W.T.; Imlay, R.; Koester, L.; Koizumi, G.; Ling, T.Y.; Mann, A.K.; Orr, R.; Reeder, D.D.; Roberts, T.; Rubbia, C.; Sard, R.; Stefanski, R.; Sulak, L.; White, H.

    1975-01-01

    The Fermilab muon beam was used as a double-bend spectrometer for measuring π +- , K +- , proton and antiproton hadronic production, Cherenkov counters being used for particle identification. Measurements were made at 0.8mrad with 300GeV protons hitting an aluminum target

  8. Measurement of proton induced thick target γ-ray yields on B, N, Na, Al and Si from 2.5 to 4.1 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Chiari, M., E-mail: chiari@fi.infn.it [INFN-Florence and Department of Physics and Astronomy, University of Florence, via G. Sansone 1, 50019 Sesto Fiorentino (Italy); Ferraccioli, G.; Melon, B.; Nannini, A.; Perego, A.; Salvestrini, L. [INFN-Florence and Department of Physics and Astronomy, University of Florence, via G. Sansone 1, 50019 Sesto Fiorentino (Italy); Lagoyannis, A.; Preketes-Sigalas, K. [Tandem Accelerator Laboratory, Institute of Nuclear and Particle Physics, NCSR “Demokritos”, 153.10 Aghia Paraskevi, Athens (Greece)

    2016-01-01

    Thick target yields for proton induced γ-ray emission (PIGE) on low-Z nuclei, namely B, N, Na, Al and Si, were measured for proton energies from 2.5 to 4.1 MeV and emission angles of 0°, 45° and 90°, at the 3 MV Tandetron laboratory of INFN-LABEC in Florence. The studied reactions were: {sup 10}B(p,α′γ){sup 7}Be (E{sub γ} = 429 keV), {sup 10}B(p,p′γ){sup 10}B (E{sub γ} = 718 keV) and {sup 11}B(p,p′γ){sup 11}B (E{sub γ} = 2125 keV) for boron; {sup 14}N(p,p′γ){sup 14}N (E{sub γ} = 2313 keV) for nitrogen; {sup 23}Na(p,p′γ){sup 23}Na (E{sub γ} = 441 and 1636 keV) and {sup 23}Na(p,α′γ){sup 20}Ne (E{sub γ} = 1634 keV) for sodium; {sup 27}Al(p,p′γ){sup 27}Al (E{sub γ} = 844 and 1014 keV) and {sup 27}Al(p,α′γ){sup 24}Mg (E{sub γ} = 1369 keV) for aluminum; {sup 28}Si(p,p′γ){sup 28}Si (E{sub γ} = 1779 keV) and {sup 29}Si(p,p′γ){sup 29}Si (E{sub γ} = 1273 keV) for silicon. The PIGE thick target yields have been measured with an overall uncertainty typically better than 10%. The use of the measured thick target yield to benchmark and validate experimental cross sections available in the literature is demonstrated.

  9. The thick-target 9Be(d,n) neutron spectra for deuteron energies between 2.6 and 7.0-MeV

    International Nuclear Information System (INIS)

    Meadows, J.W.

    1991-11-01

    The measurement of the zero deg. neutron spectra and yields from deuterons incident on thick beryllium metal targets is described. 235 U and 238 U fission ion chambers were used as neutron detectors to span the neutron energy range above 0.05-MeV with a time resolution of ≤ 3 nanosec. Measurements were made for incident deuteron energies from 2.6 to 7.0-MeV, at 0.4-MeV intervals, using time-of-flight techniques with flight paths of 2.7 and 6.8 meters. The results are presented in graphical form and in tables

  10. Angular distributions of absorbed dose of Bremsstrahlung and secondary electrons induced by 18-, 28- and 38-MeV electron beams in thick targets.

    Science.gov (United States)

    Takada, Masashi; Kosako, Kazuaki; Oishi, Koji; Nakamura, Takashi; Sato, Kouichi; Kamiyama, Takashi; Kiyanagi, Yoshiaki

    2013-03-01

    Angular distributions of absorbed dose of Bremsstrahlung photons and secondary electrons at a wide range of emission angles from 0 to 135°, were experimentally obtained using an ion chamber with a 0.6 cm(3) air volume covered with or without a build-up cap. The Bremsstrahlung photons and electrons were produced by 18-, 28- and 38-MeV electron beams bombarding tungsten, copper, aluminium and carbon targets. The absorbed doses were also calculated from simulated photon and electron energy spectra by multiplying simulated response functions of the ion chambers, simulated with the MCNPX code. Calculated-to-experimental (C/E) dose ratios obtained are from 0.70 to 1.57 for high-Z targets of W and Cu, from 15 to 135° and the C/E range from 0.6 to 1.4 at 0°; however, the values of C/E for low-Z targets of Al and C are from 0.5 to 1.8 from 0 to 135°. Angular distributions at the forward angles decrease with increasing angles; on the other hand, the angular distributions at the backward angles depend on the target species. The dependences of absorbed doses on electron energy and target thickness were compared between the measured and simulated results. The attenuation profiles of absorbed doses of Bremsstrahlung beams at 0, 30 and 135° were also measured.

  11. Measurements of spallation neutrons from a thick lead target bombarded with 0.5 and 1.5 GeV protons

    Energy Technology Data Exchange (ETDEWEB)

    Meigo, Shin-ichiro; Takada, Hiroshi; Chiba, Satoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

    1997-03-01

    Double differential neutron spectra from a thick lead target bombarded with 0.5 and 1.5 GeV protons have been measured with the time-of-flight technique. In order to obtain the neutron spectra without the effect of the flight time fluctuation by neutron scattering in the target, an unfolding technique has also been employed in the low energy region below 3 MeV. The measured data have been compared with the calculated results of NMTC/JAERI-MCNP-4A code system. It has been found that the code system gives about 50 % lower neutron yield than the experimental ones in the energy region between 20 and 80 MeV for both incident energies. The disagreements, however, have been improved well by taking account of the inmedium nucleon-nucleon scattering cross sections in the NMTC/JAERI code. (author)

  12. Evaluation of cross sections of 56Fe up to 3 GeV and integral benchmark calculation for thick target yield

    International Nuclear Information System (INIS)

    Yoshizawa, Nobuaki; Meigo, Shin-ichiro

    2001-01-01

    The neutron and proton cross sections of 56 Fe were evaluated up to 3 GeV. JENDL High Energy File of 56 Fe were developed for use in transport calculation. For neutrons, the high-energy data are merged with JENDL3.3-file. Integral benchmark calculations for thick target neutron yields (TTY) for 113 MeV and 256 MeV proton bombardment of Fe targets were performed using the evaluated libraries. Calculated TTY neutron spectra were compared with experimental data. For 113 MeV, calculated TTY at 7.5 degree underestimated in the emitted neutron energy range above 10 MeV. For 256 MeV, calculated TTY well agree with experimental data except below 10 MeV. (author)

  13. Measurement of the Time Dependence of Neutron Slowing-Down and Therma in Heavy Water

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, E

    1966-03-15

    The behaviour of neutrons during their slowing-down and thermalization in heavy water has been followed on the time scale by measurements of the time-dependent rate of reaction between the flux and the three spectrum indicators indium, cadmium and gadolinium. The space dependence of the reaction rate curves has also been studied. The time-dependent density at 1.46 eV is well reproduced by a function, given by von Dardel, and a time for the maximum density of 7.1 {+-} 0.3 {mu}s has been obtained for this energy in deuterium gas in agreement with the theoretical value of 7.2 {mu}s. The spatial variation of this time is in accord with the calculations by Claesson. The slowing- down time to 0.2 eV has been found to be 16.3 {+-}2.4 {mu}s. The approach to the equilibrium spectrum takes place with a time constant of 33 {+-}4 {mu}s, and the equilibrium has been established after about 200 {mu}s. Comparison of the measured curves for cadmium and gadolinium with multigroup calculations of the time-dependent flux and reaction rate show the superiority of the scattering models for heavy water of Butler and of Brown and St. John over the mass 2 gas model. The experiment has been supplemented with Monte Carlo calculations of the slowing down time.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-09-01

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

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

    International Nuclear Information System (INIS)

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

    2004-01-01

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

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

    International Nuclear Information System (INIS)

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

    1989-04-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-06-01

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

  18. An evaluation of the ENDF/GASKET model for thermal neutron scattering in heavy water

    International Nuclear Information System (INIS)

    Abbate, M.J.; Antunez, H.M.

    1977-06-01

    The ENDF/GASKET model for computing thermal neutron scattering was selected for studies undertaken with the purpose of getting thoroughly acquainted with the behavior of the heavy water as a moderator. As a first step in its evaluation, the scattering law S(α,β) was computed with ENDF/GASKET. A comparison of the values so obtained with others previously measured or computed showed that the model is not completely satisfactory in this respect. This is attributed to coherent scattering not included in the model and to the need of improving its frequency spectrum. Any way, the experimental values show serious descrepancies and it is difficult to reach definitive conclusions. The Legendre moments of the double differential cross section and its microscopic values were also computed. As it was found by other authors, the incoherent approximation of ENDF/GASKET results in a drastic departure from the measured total cross section below 0,006 eV. In addition, the discrepancies between measured and calculated average μ, might also imply that the coherence effects are appreciable at higher energies. Also decay constance and diffusion parameters were computed for D 2 O (100%), and these agree well with values of other sources. The measurement and computation of neutron spectra in heavy water is presently intented for the sake of completing evaluation. So far two alternatives are foreseen for further work: the improvement of ENDF/GASKET, or the evaluation of the more recent Jarvis model. (author) [es

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

    International Nuclear Information System (INIS)

    1983-01-01

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

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

    International Nuclear Information System (INIS)

    Peculea, Marius

    1999-01-01

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

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

    International Nuclear Information System (INIS)

    Ando, Hideki; Kawahara, Toshio

    1982-01-01

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

  2. Assessment of Loss-of-Coolant Effect on Pressurized Heavy Water Reactors

    International Nuclear Information System (INIS)

    Kim, Won Young; Park, Joo Hwan; Kim, Bong Ghi

    2009-01-01

    A CANDU reactor is a heavy-water-moderated, natural uranium fuelled reactor with a pressure tube. The reactor contains a horizontal cylindrical vessel (calandria) and each pressure tube is isolated from the heavy-water moderator in a calandria. This allows the moderator system to be operated of a high-pressure and of a high-temperature coolant in pressure tube. This causes the pressurized liquid coolant in the channel to void and therefore give rise to a reactivity transient in the event of a break or fault in the coolant circuit. In particular, all CANDU reactors are well known to have a positive void reactivity coefficient and thus this phenomenon may lead to a positive feedback, which can cause a large power pulse. We assess the loss-of-coolant effect by coolant void reactivity versus fuel burnup, four factor parameters for fresh fuel and equilibrium fuel, reactivity change due to the change of coolant density and reactivity change in the case of half- and full-core coolant

  3. Measurements of Void Fractions for Flow of Boiling Heavy Water in a Vertical Round Duct

    Energy Technology Data Exchange (ETDEWEB)

    Rouhani, S Z; Becker, K M

    1963-09-15

    The present report deals with measurements of void fractions for flow of boiling heavy water in a vertical round duct with 6.10 mm inner diameter and a heated length of 2500 mm. The following ranges of variables were studied and 149 void fraction measurements were obtained. Pressure 7 < p < 60 bars; Steam quality 0 < x < 0.38; Surface heat flux 38 < q/A < 120 W/cm{sup 2}; Mass velocity 650 < m'/F < 2050 kg/m/s; Void fraction 0. 24 < {alpha} < 0.88. The measurements were performed by means of a method, which is based on the ({gamma}, n) reaction, occurring when heavy water is irradiated by gamma rays. The results are presented in diagrams, where the void fractions and the slip ratios are plotted against the steam quality with the pressure as a parameter. The data have been correlated by curves, and the scatter of the data around the curves is less than {+-} 5 per cent.

  4. Method of collecting helium cover gas for heavy water moderated reactor

    International Nuclear Information System (INIS)

    Miyamoto, Keiji; Ueda, Hiroshi.

    1981-01-01

    Purpose: To reduce the systematic facility cost in a heavy water moderated reactor by contriving the simplification of a helium cover gas collecting intake system. Method: A detachable low pressure metal tank and a neoprene balloon are prepared for a vacuum pump in a permanent vacuum drying facility. When all of the helium cover gas is collected from a heavy water moderated reactor, a large capacity of neoprene balloon capable of temporarily storing it under low pressure is connected to the exhaust of the vacuum pump. On the other hand, while the reactor is operating, a suitable amount of the low pressure tank or neoprene balloon is connected to the exhaust side of the pump, thereby regulating the pressure of the helium cover gas. When refeeding the cover gas, the balloon, with a large capacity for collecting and storing the cover gas is connected to the intake side of the pump. Thus, the pressure regulation, collection of all of the cover gas and refeeding of the cover gas can be conducted without using a high discharge pump and high pressure tank. (Kamimura, M.)

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

    International Nuclear Information System (INIS)

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

    2002-09-01

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

  6. Breeding capability and void reactivity analysis of heavy-water-cooled thorium reactor

    International Nuclear Information System (INIS)

    Permana, Sidik; Takaki, Naoyuki; Sekimoto, Hiroshi

    2008-01-01

    The fuel breeding and void reactivity coefficient of thorium reactors have been investigated using heavy water as coolant for several parametric surveys on moderator-to-fuel ratio (MFR) and burnup. The equilibrium fuel cycle burnup calculation has been performed, which is coupled with the cell calculation for this evaluation. The η of 233 U shows its superiority over other fissile nuclides in the surveyed MFR ranges and always stays higher than 2.1, which indicates that the reactor has a breeding condition for a wide range of MFR. A breeding condition with a burnup comparable to that of a standard PWR or higher can be achieved by adopting a larger pin gap (1-6 mm), and a pin gap of about 2 mm can be used to achieve a breeding ratio (BR) of 1.1. A feasible design region of the reactors, which fulfills the breeding condition and negative void reactivity coefficient, has been found. A heavy-water-cooled PWR-type Th- 233 U fuel reactor can be designed as a breeder reactor with negative void coefficient. (author)

  7. Definition and Analysis of Heavy Water Reactor Benchmarks for Testing New Wims-D Libraries

    International Nuclear Information System (INIS)

    Leszczynski, Francisco

    2000-01-01

    This work is part of the IAEA-WIMS Library Update Project (WLUP). A group of heavy water reactor benchmarks have been selected for testing new WIMS-D libraries, including calculations with WIMSD5B program and the analysis of results.These benchmarks cover a wide variety of reactors and conditions, from fresh fuels to high burnup, and from natural to enriched uranium.Besides, each benchmark includes variations in lattice pitch and in coolants (normally heavy water and void).Multiplication factors with critical experimental bucklings and other parameters are calculated and compared with experimental reference values.The WIMS libraries used for the calculations were generated with basic data from JEF-2.2 Rev.3 (JEF) and ENDF/B-VI iNReleaseln 5 (E6) Results obtained with WIMS-86 (W86) library, included with WIMSD5B package, from Windfrith, UK with adjusted data, are included also, for showing the improvements obtained with the new -not adjusted- libraries.The calculations with WIMSD5B were made with two methods (input program options): PIJ (two-dimension collision probability method) and DSN (one-dimension Sn method, with homogenization of materials by ring).The general conclusions are: the library based on JEF data and the DSN meted give the best results, that in average are acceptable

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

    CERN Document Server

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

    2002-01-01

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

  9. A case study for INPRO methodology based on Indian advanced heavy water reactor

    International Nuclear Information System (INIS)

    Anantharaman, K.; Saha, D.; Sinha, R.K.

    2004-01-01

    Under Phase 1A of the International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO) a methodology (INPRO methodology) has been developed which can be used to evaluate a given energy system or a component of such a system on a national and/or global basis. The INPRO study can be used for assessing the potential of the innovative reactor in terms of economics, sustainability and environment, safety, waste management, proliferation resistance and cross cutting issues. India, a participant in INPRO program, is engaged in a case study applying INPRO methodology based on Advanced Heavy Water Reactor (AHWR). AHWR is a 300 MWe, boiling light water cooled, heavy water moderated and vertical pressure tube type reactor. Thorium utilization is very essential for Indian nuclear power program considering the indigenous resource availability. The AHWR is designed to produce most of its power from thorium, aided by a small input of plutonium-based fuel. The features of AHWR are described in the paper. The case study covers the fuel cycle, to be followed in the near future, for AHWR. The paper deals with initial observations of the case study with regard to fuel cycle issues. (authors)

  10. Measurement of the Time Dependence of Neutron Slowing-Down and Therma in Heavy Water

    International Nuclear Information System (INIS)

    Moeller, E.

    1966-03-01

    The behaviour of neutrons during their slowing-down and thermalization in heavy water has been followed on the time scale by measurements of the time-dependent rate of reaction between the flux and the three spectrum indicators indium, cadmium and gadolinium. The space dependence of the reaction rate curves has also been studied. The time-dependent density at 1.46 eV is well reproduced by a function, given by von Dardel, and a time for the maximum density of 7.1 ± 0.3 μs has been obtained for this energy in deuterium gas in agreement with the theoretical value of 7.2 μs. The spatial variation of this time is in accord with the calculations by Claesson. The slowing- down time to 0.2 eV has been found to be 16.3 ±2.4 μs. The approach to the equilibrium spectrum takes place with a time constant of 33 ±4 μs, and the equilibrium has been established after about 200 μs. Comparison of the measured curves for cadmium and gadolinium with multigroup calculations of the time-dependent flux and reaction rate show the superiority of the scattering models for heavy water of Butler and of Brown and St. John over the mass 2 gas model. The experiment has been supplemented with Monte Carlo calculations of the slowing down time

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

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  12. REACTION RATE SENSITIVITY OF 44Ti PRODUCTION IN MASSIVE STARS AND IMPLICATIONS OF A THICK TARGET YIELD MEASUREMENT OF 40Ca(α, γ)44Ti

    International Nuclear Information System (INIS)

    Hoffman, R. D.; Sheets, S. A.; Burke, J. T.; Scielzo, N. D.; Norman, E. B.; Tumey, S.; Brown, T. A.; Grant, P. G.; Hurst, A. M.; Stoyer, M. A.; Wooddy, T.; Fisker, J. L.; Bleuel, D.; Rauscher, T.; Phair, L.

    2010-01-01

    We evaluate two dominant nuclear reaction rates and their uncertainties that affect 44 Ti production in explosive nucleosynthesis. Experimentally we develop thick target yields for the 40 Ca(α, γ) 44 Ti reaction at E α = 4.13, 4.54, and 5.36 MeV using γ-ray spectroscopy. At the highest beam energy, we also performed an activation measurement which agrees with the thick target result. From the measured yields a stellar reaction rate was developed that is smaller than current statistical-model calculations and recent experimental results, which would suggest lower 44 Ti production in scenarios for the α-rich freezeout. Special attention has been paid to assessing realistic uncertainties of stellar reaction rates produced from a combination of experimental and theoretical cross sections. With such methods, we also develop a re-evaluation of the 44 Ti(α, p) 47 V reaction rate. Using these two rates we carry out a sensitivity survey of 44 Ti synthesis in eight expansions representing peak temperature and density conditions drawn from a suite of recent supernova explosion models. Our results suggest that the current uncertainty in these two reaction rates could lead to as large an uncertainty in 44 Ti synthesis as that produced by different treatments of stellar physics.

  13. 12C fragmentation at 95 MeV per nucleon for hadron-therapy. Experimental study and simulation with thick PMMA targets

    International Nuclear Information System (INIS)

    Braunn, B.

    2010-11-01

    A study of the 12 C fragmentation at 95 MeV per nucleon on thick PMMA targets is presented on this document. This study is motivated by the development of a new technique for irradiation of malignant tumours: the carbon ion therapy. The purpose of this work is to compare experimental data against nuclear models used in GEANT4 tool-kit. The aim is to determine if the models are sufficiently predictive to the criteria of hadron-therapy. To achieve this goal, a first experiment was performed at GANIL with a 12 C beam at 95 MeV/u and thick PMMA targets. This experiment has achieved the production rates, angular and energy distributions of different fragments produced in nuclear collisions. Comparisons between experimental data and simulated results obtained using the binary intra-nuclear cascade (BIC) and quantum molecular dynamics model (QMD) available in GEANT4 have been performed. These comparisons show the inability of the tested models to reproduce carbon fragmentation at 95 MeV per nucleon with the accuracy required in hadron-therapy. (author)

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

    Science.gov (United States)

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

    2018-02-01

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

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

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

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

  16. Determination of the tritium content in the reactor heavy water; Odredjivanje porasta kolicine tritijuma u reaktorskoj teskoj vodi

    Energy Technology Data Exchange (ETDEWEB)

    Ribnikar, S [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1963-01-15

    Quantity of tritium was measured in the heavy water, in the heavy water vapour and radiolyzed deuterium from the helium cover gas of the RA reactor. It has been shown that isotopic equilibrium D{sub 2}O+DT{r_reversible}DTO+D{sub 2} exists and that it is catalyzed by irradiation. Small quantities of ammonium in the reactor cover gas are inhibiting the migration of tritium from the heavy water. Izmerena ja sadrzina tritijuma u tecnoj teskoj vodi, njenoj pari i radiolizovanom deuterijumu iz helijumske atmosfere reaktora RA. Pokazano je da postoji izotopska ravnoteza D{sub 2}O+DT{r_reversible}DTO+D{sub 2}, koja je katalizovana zracenjem. Male kolicine amonijaka reaktorske atmosfere deluju u smislu otezavanja migracije tritijuma iz teske vode (author)

  17. Long-term effect of depot medroxyprogesterone acetate on vaginal microbiota, epithelial thickness and HIV target cells.

    Science.gov (United States)

    Mitchell, Caroline M; McLemore, Leslie; Westerberg, Katharine; Astronomo, Rena; Smythe, Kimberly; Gardella, Carolyn; Mack, Matthias; Magaret, Amalia; Patton, Dorothy; Agnew, Kathy; McElrath, M Juliana; Hladik, Florian; Eschenbach, David

    2014-08-15

    Depot medroxyprogesterone acetate (DMPA) has been linked to human immunodeficiency virus type 1 (HIV-1) acquisition. Vaginal microbiota of women using DMPA for up to 2 years were cultured. Mucosal immune cell populations were measured by immunohistological staining. Over 12 months, the proportion with H2O2-positive lactobacilli decreased (n = 32; 53% vs 27%; P = .03). Median vaginal CD3(+) cells also decreased (n = 15; 355 vs 237 cells/mm(2); P = .03), as did CD3(+)CCR5(+) cells (195 vs 128 cells/mm(2); P = .04), HLA-DR(+) cells (130 vs 96 cells/mm(2); P = .27), and HLA-DR(+)CCR5(+) cells (18 vs 10 cells/mm(2); P = .33). DMPA contraception does not increase vaginal mucosal CCR5(+) HIV target cells but does decrease CD3(+) T lymphocytes and vaginal H2O2-producing lactobacilli. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

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

    International Nuclear Information System (INIS)

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

    2001-02-01

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

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

    International Nuclear Information System (INIS)

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

    2002-05-01

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

  20. 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

  1. Measurement of angular distributions of K x-ray intensity of Ti and Cu thick targets following impact of 10–25 keV electrons

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Bhupendra; Kumar, Sunil; Prajapati, Suman; Singh, Bhartendu K. [Atomic Physics Laboratory, Department of Physics, Institute of Science, Banaras Hindu University, Varanasi 221005 (India); Llovet, Xavier [Scientific and Technological Centers, Universitat de Barcelona, Lluís Solé i Sabarís 1-3, 08028 Barcelona (Spain); Shanker, R., E-mail: shankerorama@gmail.com [Atomic Physics Laboratory, Department of Physics, Institute of Science, Banaras Hindu University, Varanasi 221005 (India)

    2017-04-15

    Highlights: • New results on the angular distributions of relative intensities of K-X-rays lines of Ti and Cu thick targets under electron bombardment are reported. • An increase of relative intensity of Kα and Kβ X-ray lines has been found to be about 60–70% in the detection range θ = 105{sup 0}–165{sup 0}. • There is a slight impact energy dependence of Cu Kα X-ray line. • A reasonable agreement between experimental and PENELOPE MC Calculations are obtained. - Abstract: We present new results on angular distributions of the relative intensity of K{sub α} and K{sub β} x-ray lines of thick targets of Ti (Z = 22) and Cu (Z = 29) pure elements following impact of 10–25 keV electrons. The angular measurements of the K x-radiations were accomplished by rotating the target surface with respect to the electron beam direction. The x-rays emerging from the target surface in reflection mode were detected by an energy dispersive Si P-I-N photodiode detector. The resulting variation of the relative intensity of the characteristic lines as a function of angle of detection and impact energy has been found to be anisotropic and it is considered to arise due to change in path lengths at a given incidence angle α for the photons generated by direct as well as by indirect K shell ionization processes. The measured angular variations of relative intensity of K{sub α} and K{sub β} x-ray lines of both targets are found to increase by about 60–70% in going from θ = 105{sup 0} to 165{sup 0} at a given impact energy; however there is a slight indication of impact energy dependence of Cu K{sub α} x-ray line as also noted by the earlier workers. We compare the experimental results with those obtained by Monte Carlo simulations using PENELOPE calculations; the agreement between experiment and theory is found to be satisfactory within uncertainties involved in the measurements and the theoretical results.

  2. Opinion about difficulties of RA reactor operation under conditions of high activity of the heavy water system - Annex 2

    International Nuclear Information System (INIS)

    Nikolic, M.

    1963-01-01

    It was concluded that reactor the reactor operation is very dangerous for the reactor installation as well as safety of the staff under conditions of heavy water increased activity. Two fundamental arguments in favour of this conclusion are: insufficient possibility of reactor components inspection during maintenance and operation in the future period; difficulties in prevention of accidents that could occur is equally dangerous for the reactor facility and the environment. Cleaning and decontamination of the complete heavy water system is needed before the reactor operation starts in order to avoid possible failures or accidental events [sr

  3. Heavy water production by the method of ammonia rectification with heat pump. Experience of starting of industrial installation

    International Nuclear Information System (INIS)

    Rozen, A.M.

    1995-01-01

    Basic results of the start-up in 1955 of a facility for heavy water production by ammonia refining are presented to substantiate its economic profitability. The description of the facility is given, data on the materials corrosion resistance, efficiency of the operation of the trays and pumps are provided. It is shown that the mentioned method of heavy water production in terms of economic indices is similar to highly efficient methods, namely: refining of liquid hydrogen and water-hydrogen sulfide two-temperature isotopic exchange. 14 refs., 14 figs., 2 tabs

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

    International Nuclear Information System (INIS)

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

    1989-04-01

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

  5. Power level effects on thorium-based fuels in pressure-tube heavy water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Bromley, B.P.; Edwards, G.W.R., E-mail: blair.bromley@cnl.ca [Canadian Nuclear Laboratories, Chalk River, Ontario (Canada); Sambavalingam, P. [Univ. of Ontario Inst. of Technology, Oshawa, Ontario (Canada)

    2016-06-15

    Lattice and core physics modeling and calculations have been performed to quantify the impact of power/flux levels on the reactivity and achievable burnup for 35-element fuel bundles made with Pu/Th or U-233/Th. The fissile content in these bundles has been adjusted to produce on the order of 20 MWd/kg burnup in homogeneous cores in a 700 MWe-class pressure-tube heavy water reactor, operating on a once-through thorium cycle. Results demonstrate that the impact of the power/flux level is modest for Pu/Th fuels but significant for U-233/Th fuels. In particular, high power/flux reduces the breeding and burnup potential of U-233/Th fuels. Thus, there may be an incentive to operate reactors with U-233/Th fuels at a lower power density or to develop alternative refueling schemes that will lower the time-average specific power, thereby increasing burnup.(author)

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

    International Nuclear Information System (INIS)

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

    1978-01-01

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

  7. 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

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

    International Nuclear Information System (INIS)

    Sundaresan, S.; Lakshmanan, S.

    1992-01-01

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

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

    International Nuclear Information System (INIS)

    Park, Tae Keun; Yeo, Ji Won

    1996-03-01

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

  10. Removal of decay heat by specially designed isolation condensers for advanced heavy water reactors

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-06-01

    For Advanced Heavy Water Reactor (AHWR), removal of decay heat and containment heat is being considered by passive means. For this, special type of isolation condensers are designed. Isolation condensers when submerged in a pool of water, are the best choice because condensation of high temperature steam is an extremely efficient heat transfer mechanism. By the use of isolation condensers, not only heat is removed but also pressure and temperature of the system are automatically controlled without losing the coolant and without using conventional safety relief valves. In this paper, design optimisation studies of isolation condensers of different types with natural circulation for the removal of core decay heat for AHWR is presented. (author). 8 refs., 2 figs.

  11. Microfouling assessment and its control in a heavy water production unit

    International Nuclear Information System (INIS)

    Rajesh Kumar; Subba Rao, T.

    2015-01-01

    The water treatment plant (WTP) of a heavy water production unit was extensively fouled by microorganisms. On-site investigations showed severe algal and bacterial growth in the various units of WTP and very dense microbial fouling in the vacuum degasser (VD) unit. Digital and microscopic images showed that the microfouling problem was primarily due to a slime bacterium and a fungus. Microbiological analysis showed a bacterial count of ∼10 5 cfu ml -1 in the various sections of WTP. The slime/biofilm scrapings had very high bacterial population (>10 9 cfu cm -2 ). High organic carbon values in the system (5.0 to 19.5 ppm) had supported microbial growth in WTP and augmented resin fouling. Chlorination was inadequate in controlling microfouling, consequently chlorine dioxide was tested and found to be a better biocide. A 2.0% sodium omadine solution had completely inhibited the fouling fungus. (author)

  12. Operation and utilization of low power research reactor critical facility for Advanced Heavy Water Reactor (AHWR)

    International Nuclear Information System (INIS)

    De, S.K.; Karhadkar, C.G.

    2017-01-01

    An Advanced Heavy Water Reactor (AHWR) has been designed and developed for maximum power generation from thorium considering large reserves of thorium. The design envisages using 54 pin MOX cluster with different enrichment of "2"3"3U and Pu in Thoria fuel pins. Theoretical models developed to neutron transport and the geometrical details of the reactor including all reactivity devices involve approximations in modelling, resulting in uncertainties. With a view to minimize these uncertainties, a low power research reactor Critical Facility was built in which cold clean fuel can be arranged in a desired and precise geometry. Different experiments conducted in this facility greatly contribute to understand and validate the physics design parameters

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

    International Nuclear Information System (INIS)

    Effer, W.R.

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

  14. Two-dimensional neutron scattering in a floating heavy water bridge

    International Nuclear Information System (INIS)

    Fuchs, Elmar C; Baroni, Patrick; Noirez, Laurence; Bitschnau, Brigitte

    2010-01-01

    When a high voltage is applied to pure water in two filled beakers kept close to each other, a connection forms spontaneously, giving the impression of a floating water bridge. This phenomenon is of special interest, since it comprises a number of phenomena currently tackled in modern water science. In this work, the first two-dimensional structural study of a floating heavy water bridge is presented as a function of the azimuthal angle. A small anisotropy in the angular distribution of the intensity of the first structural peak was observed, indicating a preferred orientation of a part of the D 2 O molecules along the electric field lines without breaking the local tetrahedral symmetry. The experiment is carried out by neutron scattering on a D 2 O bridge.

  15. Two-dimensional neutron scattering in a floating heavy water bridge

    Science.gov (United States)

    Fuchs, Elmar C.; Baroni, Patrick; Bitschnau, Brigitte; Noirez, Laurence

    2010-03-01

    When a high voltage is applied to pure water in two filled beakers kept close to each other, a connection forms spontaneously, giving the impression of a floating water bridge. This phenomenon is of special interest, since it comprises a number of phenomena currently tackled in modern water science. In this work, the first two-dimensional structural study of a floating heavy water bridge is presented as a function of the azimuthal angle. A small anisotropy in the angular distribution of the intensity of the first structural peak was observed, indicating a preferred orientation of a part of the D2O molecules along the electric field lines without breaking the local tetrahedral symmetry. The experiment is carried out by neutron scattering on a D2O bridge.

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  17. Radiation characteristics of spent fuel of heavy-water research reactor during long-term storage

    International Nuclear Information System (INIS)

    Gerasimov, A.S.; Kiselev, G.V.; Myrtsymova, L.A.; Zaritskaya, T.S.

    2002-01-01

    Decay heat power and radiotoxicity by water of actinides and fission products from spent fuel of heavy-water research reactor RA were calculated for period of storage during 300000 years. Three variants of fuel enrichment by 235 U were considered: 2%, 21%, and 80%. The mass of 235 U in one fuel element was supposed to be the same for all variants of enrichment. The decay heat power of fission products in initial period is about 20 times higher than that of actinides. Decay heat power and radiotoxicity of actinides do not practically decrease during long period of time as they are determined by nuclides with very long half-life periods. (author)

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

    International Nuclear Information System (INIS)

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

    1990-01-01

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

  19. Current developments and future challenges in physics analyses of the NRU heavy water research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, S.; Wilkin, B.; Leung, T., E-mail: nguyens@aecl.ca, E-mail: leungt@aecl.ca [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2011-07-01

    The National Research Universal (NRU) reactor is heavy water cooled and moderated, with on-power fueling capability. TRIAD, a 3D two-group diffusion code, is currently used for support of day-to-day NRU operations. Recently, an MCNP full reactor model of NRU has been developed for benchmarking TRIAD. While reactivity changes and flux and power distributions from both methods are in reasonably good agreement, MCNP appears to eliminate a k-eff bias in TRIAD. Beyond TRIAD's capability, MCNP enables the assessment of radiation in the NRU outer structure. Challenges include improving TRIAD accuracy and MCNP performance, as well as performing NRU core-following using MCNP. (author)

  20. Probablistic risk assessment methodology application to Indian pressurised heavy water reactors

    International Nuclear Information System (INIS)

    Babar, A.K.; Grover, R.B.; Mehra, V.K.; Gangwal, D.K.; Chakraborty, G.

    1987-01-01

    Probabilistic risk assessment in the context of nuclear power plants is associated with models that predict the offsite radiological releases resulting from reactor accidents. Level 1 PRA deals with the identification of accident sequences relevant to the design of a system and also with their quantitative estimation. It is characterised by event tree, fault tree analysis. The initiating events applicable to pressurised heavy water reactors have been considered and the dominating initiating events essential for detailed studies are identified in this paper. Reliability analysis and the associated problems encountered during the case studies are mentioned briefly. It is imperative to validate the failure data used for analysis. Bayesian technique has been employed for the same and a brief account is included herein. A few important observations, e.g. effects of the presence of moderator, made during the application of probabilistic risk assessment methodology are also discussed. (author)

  1. Multidimensional space-time kinetics of a heavy water moderated nuclear reactor

    International Nuclear Information System (INIS)

    Winn, W.G.; Baumann, N.P.; Jewell, C.E.

    1980-01-01

    Diffusion theory analysis of a series of multidimensional space-time experiments is appraised in terms of the final experiment of the series. In particular, TRIMHX diffusion calculations were examined for an experiment involving free-fall insertion of a 235 U-bearing rod into a heavy water moderated reactor with a large reflector. The experimental transient flux-tilts were accurately reproduced after cross section adjustments forced agreement between static diffusion calculations and static reactor measurements. The time-dependent features were particularly well modeled, and the bulk of the small discrepancies in space-dependent features should be removable by more refined cross-section adjustments. This experiment concludes a series of space-time experiments that span a wide range of delayed neutron holdback effects. TRIMHX calculations of these experiments demonstrate the accuracy of the modeling employed in the code

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

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  3. Acoustic emission technique for leak detection in an end shield of a pressurized heavy water reactor

    International Nuclear Information System (INIS)

    Kalyanasundaram, P.; Jayakumar, T.; Raj, B.

    1989-01-01

    This paper discusses the successful application of the Acoustic Emission Technique (AET) for detection and location of leak paths present on the inaccessible side of an end shield of a Pressurized Heavy Water Reactor (PHWR). The methodology was based on the fact that air and water leak AE signals have different characteristic features. Baseline data was generated from a sound end-shield of a PHWR for characterizing the background noise. A mock up end-shield system with saw cut leak paths was used to verify the validity of the methodology. It was found that air leak signals under pressurisation (as low as 3 psi) could be detected by frequency domain analysis. Signals due to air leaks from various locations of a defective end-shield were acquired and analysed. It was possible to detect and locate leak paths. Presence of detected leak paths were further confirmed by alternate test. (orig.)

  4. Tritium isotope separation from light and heavy water by bipolar electrolysis

    International Nuclear Information System (INIS)

    Petek, M.; Ramey, D.W.; Taylor, R.D.; Kobisk, E.H.

    1980-01-01

    A process for separating tritium from light and heavy water is described. Hydrogen is transferred at and through bipolar electrodes at rates H > D > T. In a cell containing several bipolar electrodes placed in series between two terminal electrodes, a flow of hydrogen is established from the terminal anode compartment toward the terminal cathode. An electrolyte feed containing tritium is continuously added to the system and is subsequently transported countercurrent to the hydrogen mass transfer. A cascaded system is established, in which effluent streams enriched and depleted in tritium can be withdrawn. The voltage drop is smaller at any bipolar electrode as compared to the voltage for normal electrolysis. Cell design is compact because isotope separation occurs at bipolar electrodes without evolution of gas. Isotope separation was demonstrated in laboratory cells where a steady-state tritium concentration gradient was attained. This gradient was in agreement with concentrations calculated from a derived mathematical model

  5. Mid-IR absorption sensing of heavy water using a silicon-on-sapphire waveguide.

    Science.gov (United States)

    Singh, Neetesh; Casas-Bedoya, Alvaro; Hudson, Darren D; Read, Andrew; Mägi, Eric; Eggleton, Benjamin J

    2016-12-15

    We demonstrate a compact silicon-on-sapphire (SOS) strip waveguide sensor for mid-IR absorption spectroscopy. This device can be used for gas and liquid sensing, especially to detect chemically similar molecules and precisely characterize extremely absorptive liquids that are difficult to detect by conventional infrared transmission techniques. We reliably measure concentrations up to 0.25% of heavy water (D2O) in a D2O-H2O mixture at its maximum absorption band at around 4 μm. This complementary metal-oxide-semiconductor (CMOS) compatible SOS D2O sensor is promising for applications such as measuring body fat content or detection of coolant leakage in nuclear reactors.

  6. Technical solutions for tritium removal from Cernavoda NPP heavy water systems

    International Nuclear Information System (INIS)

    Barariu, Gheorghe; Panait, Adrian

    2002-01-01

    In CANDU nuclear plants 2400 KCi/GW(e) - year tritium is generated. At a CANDU - 600 reactor similar to Cernavoda NPP Unit 1, 1500 KCi/year of tritium is generated 95% being in the D 2 O moderator, which can achieve a radioactivity level of 80 - 100 Ci/kg. Tritium in heavy water contributes with 30 - 50% to the doses received by operation personnel and with 20% to the radioactivity released to the environment. The extraction of tritium heavy water at CANDU reactors implies the following possibilities: - the radioactivity level reduction in the operation area; - the maintenance and repair cost reduction due to reduction of personnel protection measures and increased labor productivity; - the increase of NPP utilization factor by shutdown time reduction for maintenance and repair; - tritium concentration reduction from technological systems, ensuring thus the possibility of redesigning the systems in order to lower the cost of investment; - profitable use of extracted tritium. Technical measures provided by AECL project for CANDU 600 at Cernavoda make possible to satisfy the current standards concerning tritium concentration in the operation area atmosphere of 5 x 10 -6 Ci/m 3 . The regulations recommend that the radioactivity level should be maintained as low as possible in conformity with ALARA principles. Also, it is possible that norms will become more restrictive in the future, so the tritium removal technology is a good preventive measure which may become very necessary. The methods, which currently reached the industrial or pilot stages, are based on catalyzed chemical exchange, the heavy water electrolysis, and deuterium distillation. They are known as: VPCE - Vapour Phase Catalytic Exchange; LPCE - Liquid Phase Catalytic Exchange; DE - Direct Electrolysis; CD - Cryogenic Distillation. As transfer processes the catalyzed chemical exchange and heavy water electrolysis are used while concentration of tritium gas is done by cryogenic distillation. At present the

  7. Effects of heavy water on ultrastructural and functional status of Hep 2 and CHO cells lysosomes

    International Nuclear Information System (INIS)

    Buzgariu, Wanda; Caloianu, Maria; Zarnescu, Otilia; Cimpean, Anisoara; Titescu, Gh.; Stefanescu, I.

    2002-01-01

    The heavy water effects on the ultrastructure and function of Hep 2 and CHO lysosomal cell compartment were investigated using electron microscopy and enzymatic studies. The cell viability, measured by neutral red uptake assay, and the total protein content determination, have shown a dose dependent decrease in cell growth for both studied cell types. The electron microscopy study has revealed a progressive increase in number and size of lysosomes and autophagosomes after 96 h exposure to different deuterium concentration media in a dose dependent manner. The enzymatic determination in the lysosomal pellet revealed an increased acid phosphatase activity in both cell types (15% and 33% for Hep 2 and 24% and 52% for CHO, respectively) exposed to media with high (65%, 90%) D 2 O content. (authors)

  8. Power level effects on thorium-based fuels in pressure-tube heavy water reactors

    International Nuclear Information System (INIS)

    Bromley, B.P.; Edwards, G.W.R.; Sambavalingam, P.

    2016-01-01

    Lattice and core physics modeling and calculations have been performed to quantify the impact of power/flux levels on the reactivity and achievable burnup for 35-element fuel bundles made with Pu/Th or U-233/Th. The fissile content in these bundles has been adjusted to produce on the order of 20 MWd/kg burnup in homogeneous cores in a 700 MWe-class pressure-tube heavy water reactor, operating on a once-through thorium cycle. Results demonstrate that the impact of the power/flux level is modest for Pu/Th fuels but significant for U-233/Th fuels. In particular, high power/flux reduces the breeding and burnup potential of U-233/Th fuels. Thus, there may be an incentive to operate reactors with U-233/Th fuels at a lower power density or to develop alternative refueling schemes that will lower the time-average specific power, thereby increasing burnup.(author)

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

    International Nuclear Information System (INIS)

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

    1991-01-01

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

  10. MCCI study for Pressurized Heavy Water Reactor under hypothetical accident condition

    International Nuclear Information System (INIS)

    Verma, Vishnu; Mukhopadhyay, Deb; Chatterjee, B.; Singh, R.K.; Vaze, K.K.

    2011-01-01

    In case of severe core damage accident in Pressurized Heavy Water Reactor (PHWR), large amount of molten corium is expected to come out into the calandria vault due to failure of calandria vessel. Molten corium at high temperature is sufficient to decompose and ablate concrete. Such attack could fail CV by basement penetration. Since containment is ultimate barrier for activity release. The Molten Core Concrete Interaction (MCCI) of the resulting pool of debris with the concrete has been identified as an important part of the accident sequence. MCCI Analysis has been carried out for PHWR for a hypothetical accident condition where total core material is considered to be relocated in calandria vault. Concrete ablation rate in vertical and radial direction is evaluated for rectangular geometry using MEDICIS module of ASTEC Code. Amount of gases released during MCCI is also evaluated. (author)

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

    Directory of Open Access Journals (Sweden)

    Naoyuki Takaki

    2012-08-01

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

  12. Control of xenon oscillations in Advanced Heavy Water Reactor via two-stage decomposition

    International Nuclear Information System (INIS)

    Munje, R.K.; Parkhe, J.G.; Patre, B.M.

    2015-01-01

    Highlights: • Singularly perturbed model of Advanced Heavy Water Reactor is explored. • Composite controller is designed using slow subsystem alone, which achieves asymptotic stability. • Nonlinear simulations are carried out under different transient conditions. • Performance of the controller is found to be satisfactory. - Abstract: Xenon induced spatial oscillations developed in large nuclear reactors, like Advanced Heavy Water Reactor (AHWR) need to be controlled for safe operation. Otherwise, a serious situation may arise in which different regions of the core may undergo variations in neutron flux in opposite phase. If these oscillations are left uncontrolled, the power density and rate of change of power at some locations in the reactor core may exceed their respective thermal limits, resulting in fuel failure. In this paper, a state feedback based control strategy is investigated for spatial control of AHWR. The nonlinear model of AHWR including xenon and iodine dynamics is characterized by 90 states, 5 inputs and 18 outputs. The linear model of AHWR, obtained by linearizing the nonlinear equations is found to be highly ill-conditioned. This higher order model of AHWR is first decomposed into two comparatively lower order subsystems, namely, 73rd order ‘slow’ subsystem and 17th order ‘fast’ subsystem using two-stage decomposition. Composite control law is then derived from individual subsystem feedback controls and applied to the vectorized nonlinear model of AHWR. Through the dynamic simulations it is observed that the controller is able to suppress xenon induced spatial oscillations developed in AHWR and the overall performance is found to be satisfactory

  13. Role of passive valves & devices in poison injection system of advanced heavy water reactor

    International Nuclear Information System (INIS)

    Sapra, M.K.; Kundu, S.; Vijayan, P.K.; Vaze, K.K.; Sinha, R.K.

    2014-01-01

    The Advanced Heavy Water Reactor (AHWR) is a 300 MWe pressure tube type boiling light water (H 2 O) cooled, heavy water (D 2 O) moderated reactor. The reactor design is based on well-proven water reactor technologies and incorporates a number of passive safety features such as natural circulation core cooling; direct in-bundle injection of light water coolant during a Loss of Coolant Accident (LOCA) from Advanced Accumulators and Gravity Driven Water Pool by passive means; Passive Decay Heat Removal using Isolation Condensers, Passive Containment Cooling System and Passive Containment Isolation System. In addition to above, there is another passive safety system named as Passive Poison Injection System (PPIS) which is capable of shutting down the reactor for a prolonged time. It is an additional safety system in AHWR to fulfill the shutdown function in the event of failure of wired shutdown systems i.e. primary and secondary shut down systems of the reactor. When demanded, PPIS injects the liquid poison into the moderator by passive means using passive valves and devices. On increase of main heat transport (MHT) system pressure beyond a predetermined value, a set of rupture disks burst, which in-turn actuate the passive valve. The opening of passive valve initiates inrush of high pressure helium gas into poison tanks to push the poison into the moderator system, thereby shutting down the reactor. This paper primarily deals with design and development of Passive Poison Injection System (PPIS) and its passive valves & devices. Recently, a prototype DN 65 size Poison Injection Passive Valve (PIPV) has been developed for AHWR usage and tested rigorously under simulated conditions. The paper will highlight the role of passive valves & devices in PPIS of AHWR. The design concept and test results of passive valves along with rupture disk performance will also be covered. (author)

  14. Application of Genetic Algorithm methodologies in fuel bundle burnup optimization of Pressurized Heavy Water Reactor

    International Nuclear Information System (INIS)

    Jayalal, M.L.; Ramachandran, Suja; Rathakrishnan, S.; Satya Murty, S.A.V.; Sai Baba, M.

    2015-01-01

    Highlights: • We study and compare Genetic Algorithms (GA) in the fuel bundle burnup optimization of an Indian Pressurized Heavy Water Reactor (PHWR) of 220 MWe. • Two Genetic Algorithm methodologies namely, Penalty Functions based GA and Multi Objective GA are considered. • For the selected problem, Multi Objective GA performs better than Penalty Functions based GA. • In the present study, Multi Objective GA outperforms Penalty Functions based GA in convergence speed and better diversity in solutions. - Abstract: The work carried out as a part of application and comparison of GA techniques in nuclear reactor environment is presented in the study. The nuclear fuel management optimization problem selected for the study aims at arriving appropriate reference discharge burnup values for the two burnup zones of 220 MWe Pressurized Heavy Water Reactor (PHWR) core. Two Genetic Algorithm methodologies namely, Penalty Functions based GA and Multi Objective GA are applied in this study. The study reveals, for the selected problem of PHWR fuel bundle burnup optimization, Multi Objective GA is more suitable than Penalty Functions based GA in the two aspects considered: by way of producing diverse feasible solutions and the convergence speed being better, i.e. it is capable of generating more number of feasible solutions, from earlier generations. It is observed that for the selected problem, the Multi Objective GA is 25.0% faster than Penalty Functions based GA with respect to CPU time, for generating 80% of the population with feasible solutions. When average computational time of fixed generations are considered, Penalty Functions based GA is 44.5% faster than Multi Objective GA. In the overall performance, the convergence speed of Multi Objective GA surpasses the computational time advantage of Penalty Functions based GA. The ability of Multi Objective GA in producing more diverse feasible solutions is a desired feature of the problem selected, that helps the

  15. The key design features of the Indian advanced heavy water reactor

    International Nuclear Information System (INIS)

    Sinha, R.K.; Kakodkar, A.; Anand, A.K.; Venkat Raj, V.; Balakrishnan, K.

    1999-01-01

    The 235 MWe Indian Advanced Heavy Water Reactor (AHWR) is a vertical, pressure tube type, boiling light water cooled reactor. The three key specific features of design of the AHWR, having a large impact on its viability, safety and economics, relate to its reactor physics, coolant channel, and passive safety features. The reactor physics design is tuned for maximising use of thorium based fuel, and achieving a slightly negative void coefficient of reactivity. The fulfilment of these requirements has been possible through use of PuO 2 -ThO 2 MOX, and ThO 2 -U 233 O 2 MOX in different pins of the same fuel cluster, and use of a heterogeneous moderator consisting of pyrolytic carbon and heavy water in 80%-20% volume ratio. The coolant channels of AHWR are designed for easy replaceability of pressure tubes, during normal maintenance shutdowns. The removal of pressure tube along with bottom end-fitting, using rolled joint detachment technology, can be done in AHWR coolant channels without disturbing the top end-fitting, tail pipe and feeder connections, and all other appendages of the coolant channel. The AHWR incorporates several passive safety features. These include core heat removal through natural circulation, direct injection of Emergency Core Coolant System (ECCS) water in fuel, passive systems for containment cooling and isolation, and availability of a large inventory of borated water in overhead Gravity Driven Water Pool (GDWP) to facilitate sustenance of core decay heat removal, ECCS injection, and containment cooling for three days without invoking any active systems or operator action. Incorporation of these features has been done together with considerable design simplifications, and elimination of several reactor grade equipment. A rigorous evaluation of feasibility of AHWR design concept has been completed. The economy enhancing aspects of its key design features are expected to compensate for relative complexity of the thorium fuel cycle activities

  16. TiO2 thin and thick films grown on Si/glass by sputtering of titanium targets in an RF inductively coupled plasma

    International Nuclear Information System (INIS)

    Valencia-Alvarado, R; López-Callejas, R; Mercado-Cabrera, A; Peña-Eguiluz, R; Muñoz-Castro, A E; Rodríguez-Méndez, B G; De la Piedad-Beneitez, A; De la Rosa-Vázquez, J M

    2015-01-01

    TiO 2 thin and thick films were deposited on silicon/glass substrates using RF inductive plasma in continuous wave. The films thickness, as well as phases control, is achieved with a gradual increase in temperature substrates varying supplied RF power or working gas pressure besides deposition time as well. The deposition conditions were: argon 80%/oxygen 20% carefully calibrated mixture of 2 to 7×10 −2 mbar as working gas pressure range. Deposition time 0.5 to 5 hours, 500 or 600 W RF power at 13.56 MHz frequency and 242-345 °C substrates temperature range. The titanium dioxide deposited on the substrates is grown by sputtering of a titanium target negatively polarized at 3-5 kV DC situated 14 mm in front of such substrates. The plasma reactor is a simple Pyrex-like glass cylindrical vessel of 50 cm long and 20 cm in diameter. Using the before describe plasma parameters we obtained films only anatase and both anatase/rutile phases with stoichiometric different. The films were characterized by X-ray photoelectron spectroscopy (XPS), stylus profilometer, X-ray diffraction (XRD), scanning electron microscopy (SEM) and Raman spectroscopy. (paper)

  17. A cylindrical multiwire high-pressure gas proportional chamber surrounding a gaseous $_{2} target with a mylar separation foil $6 \\mu m thick

    CERN Document Server

    Gastaldi, Ugo; Averdung, H; Bailey, J; Beer, G A; Dreher, B; Erdman, K L; Klempt, E; Merle, K; Neubecker, K; Sabev, C; Schwenk, H; Wendling, R D; White, B L; Wodrich, R

    1978-01-01

    The characteristics and performances of a cylindrical multiwire proportional chamber built and used at CERN in experiment S142 for the study of the pp atom spectroscopy are presented. The chamber surrounds a high-pressure gaseous H/sub 2/ target, from which it is separated by a very thin window (6 mu m mylar foil). The active volume (90 cm long; 2 cm thick, internal diameter=30 cm) is divided into 36 equal and independent cells each covering 10 degrees in azimuth. At 4 abs. atm the detection efficiency for X-rays is higher than 20% in the whole energy range 1.5-15 keV. Typical resolutions are 35% fwhm for the 3 ke V Ar fluorescence line and 25% fwhm for the 5.5 keV /sup 54/Mn line. Working pressures from 0.5 to 16 abs. atm have been used. (8 refs).

  18. Calibration of an analyzing magnet using the 12C(d, p0)13C nuclear reaction with a thick carbon target

    Science.gov (United States)

    Andrade, E.; Canto, C. E.; Rocha, M. F.

    2017-09-01

    The absolute energy of an ion beam produced by an accelerator is usually determined by an electrostatic or magnetic analyzer, which in turn must be calibrated. Various methods for accelerator energy calibration are extensively reported in the literature, like nuclear reaction resonances, neutron threshold, and time of flight, among others. This work reports on a simple method to calibrate the magnet associated to a vertical 5.5 MV Van de Graaff accelerator. The method is based on bombarding with deuteron beams a thick carbon target and measuring with a surface barrier detector the particle energy spectra produced. The analyzer magnetic field is measured for each spectrum and the beam energy is deduced by the best fit of the simulation of the spectrum with the SIMNRA code that includes 12C(d,p0)13C nuclear cross sections.

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

    International Nuclear Information System (INIS)

    Dias Vargas, F.

    1983-01-01

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

  20. Study of the modifications on the synchronous generators, heavy water pumps and condenser batteries of the RA reactor - Annex 17

    International Nuclear Information System (INIS)

    Milosevic, M.

    1964-01-01

    Modifications done on the synchronous generators are related to the emergency power supply system, meaning one of the most important devices responsible for reactor safety. Without reducing the efficiency of the heavy water pumps the improved stability of generators operation was achieved by reducing the possibility of errors and simplifying manipulation. Condensator batteries were improved in order to decrease the leakage currents

  1. Effects of moderation level on core reactivity and. neutron fluxes in natural uranium fueled and heavy water moderated reactors

    International Nuclear Information System (INIS)

    Khan, M.J.; Aslam; Ahmad, N.; Ahmed, R.; Ahmad, S.I.

    2005-01-01

    The neutron moderation level in a nuclear reactor has a strong influence on core multiplication, reactivity control, fuel burnup, neutron fluxes etc. In the study presented in this article, the effects of neutron moderation level on core reactivity and neutron fluxes in a typical heavy water moderated nuclear research reactor is explored and the results are discussed. (author)

  2. 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

  3. Analysis of possible accidents on the heavy water system - Annex 4; Prilog 4 - Analiza mogucih akcidenata na sistemu teske vode

    Energy Technology Data Exchange (ETDEWEB)

    Krstic, D [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1963-12-15

    Analysis of operation of the RA reactor heavy water system has shown that so far there were no failures that could cause reactor shutdown. Consequences of system failures and interruption of heavy water cooling of the core would be very serious. That is the reason for analyzing and estimating these type of failures of system components that could affect the tightness of the system or interrupt its function. The important elements of the heavy water system are: operating cylinder, heavy water pumps, heat exchanger, main and drainage pipes with distribution construction. Failure analysis of all the mentioned system components was done. [Serbo-Croat] Analiza dosadasnjeg rada sistema teske vode na reaktoru RA pokazala je da nije bilo ostecenja i kvarova takvog obima koji bi doveli do prestanka rada reaktora. Posledice ostecenja sistema i prestanak cirkulacije teske vode za potrebe hladjenja jezgra bile bi velike. Zato je potreno analizirati i predvideti takva ostecenja na elementima sistema zbog kojih bi doslo do narusavanja hermeticnosti sistema ili prestanak njegovog rada. Osnovni elementi sitema teske vode su: radni cilindar, pumpe teske vode, izmenjivac toplote, glavni i drenazni cevovodi sa razvodnom armaturom. Uradjena je analiza ostecenja na svim navedenim komponentama sistema.

  4. General design and main problems of a gas-heavy-water power reactor contained in a pressure vessel

    International Nuclear Information System (INIS)

    Roche, R.; Gaudez, J.C.

    1964-01-01

    In the framework of research carried out on a CO 2 -cooled power reactor moderated by heavy water, the so-called 'pressure vessel' solution involves the total integration of the core, of the primary circuit (exchanges and blowers) and of the fuel handling machine inside a single, strong, sealed vessel made of pre-stressed concrete. A vertical design has been chosen: the handling 'attic' is placed above the core, the exchanges being underneath. This solution makes it possible to standardize the type of reactor which is moderated by heavy-water or graphite and cooled by a downward stream of carbon dioxide gas; it has certain advantages and disadvantages with respect to the pressure tube solution and these are considered in detail in this report. Extrapolation presents in particular.problems due specifically to the heavy water (for example its cooling,its purification, the balancing of the pressures of the heavy water and of the gas, the assembling of the internal structures, the height of the attic, etc. (authors) [fr

  5. Simulation study of neutron production in thick beryllium targets by 35 MeV and 50.5 MeV proton beams

    Science.gov (United States)

    Shin, Jae Won; Park, Tae-Sun

    2017-09-01

    A data-driven nuclear model dedicated to an accurate description of neutron productions in beryllium targets bombarded by proton beams is developed as a custom development that can be used as an add-on to GEANT4 code. The developed model, G4Data(Endf7.1), takes as inputs the total and differential cross section data of ENDF/B-VII.1 for not only the charge-exchange 9Be(p,n)9B reaction which produces discrete neutrons but also the nuclear reactions relevant for the production of continuum neutrons such as 9Be(p,pn)8Be and 9Be(p,n α) 5Li . In our benchmarking simulations for two experiments with 35 MeV and 50.5 MeV proton beams impinged on 1.16 and 1.05 cm thick beryllium targets, respectively, we find that the G4Data(Endf7.1) model can reproduce both the total amounts and the spectral shapes of the measured neutron yield data in a satisfactory manner, while all the considered hadronic models of GEANT4 cannot.

  6. A Test of Thick-Target Nonuniform Ionization as an Explanation for Breaks in Solar Flare Hard X-Ray Spectra

    Science.gov (United States)

    Holman, gordon; Dennis Brian R.; Tolbert, Anne K.; Schwartz, Richard

    2010-01-01

    Solar nonthermal hard X-ray (HXR) flare spectra often cannot be fitted by a single power law, but rather require a downward break in the photon spectrum. A possible explanation for this spectral break is nonuniform ionization in the emission region. We have developed a computer code to calculate the photon spectrum from electrons with a power-law distribution injected into a thick-target in which the ionization decreases linearly from 100% to zero. We use the bremsstrahlung cross-section from Haug (1997), which closely approximates the full relativistic Bethe-Heitler cross-section, and compare photon spectra computed from this model with those obtained by Kontar, Brown and McArthur (2002), who used a step-function ionization model and the Kramers approximation to the cross-section. We find that for HXR spectra from a target with nonuniform ionization, the difference (Delta-gamma) between the power-law indexes above and below the break has an upper limit between approx.0.2 and 0.7 that depends on the power-law index delta of the injected electron distribution. A broken power-law spectrum with a. higher value of Delta-gamma cannot result from nonuniform ionization alone. The model is applied to spectra obtained around the peak times of 20 flares observed by the Ramaty High Energy Solar Spectroscopic Imager (RHESSI from 2002 to 2004 to determine whether thick-target nonuniform ionization can explain the measured spectral breaks. A Monte Carlo method is used to determine the uncertainties of the best-fit parameters, especially on Delta-gamma. We find that 15 of the 20 flare spectra require a downward spectral break and that at least 6 of these could not be explained by nonuniform ionization alone because they had values of Delta-gamma with less than a 2.5% probability of being consistent with the computed upper limits from the model. The remaining 9 flare spectra, based on this criterion, are consistent with the nonuniform ionization model.

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

    International Nuclear Information System (INIS)

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

    1999-01-01

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

  8. Charge state and incident energy dependence of K X-ray emission as a function of target thickness for 50-165 MeV Cu ions incident on 11-250 μg/cm2 Cu

    International Nuclear Information System (INIS)

    Momoi, T.; Shima, K.; Umetani, K.; Moriyama, M.; Ishihara, T.; Mikumo, T.

    1986-01-01

    Thin self-supporting Cu targets in 11-250 μg/cm 2 thickness were bombarded with 50-165 MeV Cu sup(qi + ) ions (7 + )+Cu. From the observed K X-ray yields, K-shell vacancy production cross sections averaged over the target thickness t of projectile sigmasub(KV) and target sigmasup(*)sub(KV) were separately derived taking into account the fluorescence yield that can be estimated from the Ksub(α) X-ray energy shift. When the values of sigmasub(KV) and sigmasup(*)sub(KV) are extrapolated to zero foil thickness, the K shell vacancy formed in the collision has been found to be equally shared between projectile and target in a single collision. With the increase of penetration depth, however, the values of sigmasup(*)sub(KV) are greater than those of sigmasub(KV) presumably due to electron transfer of a target K electron to the projectile K vacancy. The evolution process of projectile excited states as a function of target thickness and the resulting variation of projectile and target K X-ray emissions are discussed. (orig.)

  9. Design and development of face seal type sealing plug for advanced heavy water reactor

    International Nuclear Information System (INIS)

    Bansal, S.; Bhattacharyya, S.; Patel, R.J.; Agrawal, R.G.; Vaze, K.K.

    2005-09-01

    Advanced Heavy Water Reactor is a vertical pressure tube type reactor having light water as its coolant and heavy water as moderator. Sealing plug is required to close the pressure boundary of main heat transport system of the reactor by preventing escape of light water/steam From the coolant channel. There are 452 coolant channels in the reactor located in square lattice pitch. Sealing plug is located at the top of each coolant channel (in the top end fitting). Top end fitting is having a stepped bore to create a sealing face. Sealing plug is held through its expanded jaws in a specially provided groove of the end fitting. The plug was designed and prototypes were manufactured considering its functional importance, intricate design and precision machining requirements. Sealing plug consists of about 20 components mostly made up of precipitation hardening stainless steel, which is suitable for water environment and meets other requirements of strength and resistance to wear and galling. Seal disc is a critical component of the sealing plug as it is the pressure-retaining component. It is a circular disc with protruded stem. One face of the seal disc is nickel plated in the peripheral area that creates the sealing by abutting against the sealing face provided in the end fitting. The typical shape and profile of seal disc provides flexibility and allows elastic deformation to assist in locking of sealing plug and creating adequate seating force for effective sealing. Design and development aspects of the sealing plug have been detailed out in this report. Also results of stress analysis and experimental studies for seal disc have been mentioned in the report. Stress analysis and experimental testing was required for the seal disc because high stresses are developed due to its exposure to high pressure and temperature environment of Main Heat Transport system. Hot testing was carried out to simulate the reactor-simulated condition. The performance was found to be

  10. Further evaluations of the toxicity of irradiated advanced heavy water reactor fuels.

    Science.gov (United States)

    Edwards, Geoffrey W R; Priest, Nicholas D

    2014-11-01

    The neutron economy and online refueling capability of heavy water moderated reactors enable them to use many different fuel types, such as low enriched uranium, plutonium mixed with uranium, or plutonium and/or U mixed with thorium, in addition to their traditional natural uranium fuel. However, the toxicity and radiological protection methods for fuels other than natural uranium are not well established. A previous paper by the current authors compared the composition and toxicity of irradiated natural uranium to that of three potential advanced heavy water fuels not containing plutonium, and this work uses the same method to compare irradiated natural uranium to three other fuels that do contain plutonium in their initial composition. All three of the new fuels are assumed to incorporate plutonium isotopes characteristic of those that would be recovered from light water reactor fuel via reprocessing. The first fuel investigated is a homogeneous thorium-plutonium fuel designed for a once-through fuel cycle without reprocessing. The second fuel is a heterogeneous thorium-plutonium-U bundle, with graded enrichments of U in different parts of a single fuel assembly. This fuel is assumed to be part of a recycling scenario in which U from previously irradiated fuel is recovered. The third fuel is one in which plutonium and Am are mixed with natural uranium. Each of these fuels, because of the presence of plutonium in the initial composition, is determined to be considerably more radiotoxic than is standard natural uranium. Canadian nuclear safety regulations require that techniques be available for the measurement of 1 mSv of committed effective dose after exposure to irradiated fuel. For natural uranium fuel, the isotope Pu is a significant contributor to the committed effective dose after exposure, and thermal ionization mass spectrometry is sensitive enough that the amount of Pu excreted in urine is sufficient to estimate internal doses, from all isotopes, as low

  11. Small angle neutron scattering study of the gemini nonionic surfactant in heavy water solutions

    International Nuclear Information System (INIS)

    Rajewska, A

    2012-01-01

    The nonionic gemini surfactant α α'-[2,4,7,9-tetramethyl-5-decyne-4,7diyl]bis[ω hydroxyl-polyoxyethylene] (S-10) was investigated in heavy water solutions only for concentrations: 2.3%, 2.5%,3%, 3.4%, 4% and 5% at temperature 25 C with small angle neutron scattering (SANS) method. All of surfactants solutions were prepared using D 2 O (99.9% deuterated, Prikladnaia Chimia, St. Petersburg, Russia) as a solvent. The nonionic gemini surfactant S-10 was obtained from Air Products and Chemicals, Inc., and used without further purification. All SANS measurements were performed on V-4 SANS spectrometer at BENSC, Berlin (Germany). Neutrons were used in wavelength range of 0.02 - 4 nm - 1. For the measurements quartz cells of were used during experiment. Up to 14 such cells were placed in a holder. Results from experiment was calculated and evaluated with PCG 2.0 program from Graz University (Austria). In the investigated solutions two axis ellipsoidal micelles was observed.

  12. Damage evaluation of 500 MWe Indian Pressurized Heavy Water Reactor nuclear containment for aircraft impact

    Energy Technology Data Exchange (ETDEWEB)

    Kukreja, Mukesh [Reactor Safety Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)]. E-mail: mrkukreja@yahoo.com

    2005-08-01

    Safety assessment of Indian nuclear containments has been carried out for aircraft impact. The loading time history for Boeing and Airbus categories of aircrafts is generated based on the principle of momentum transfer of crushable aircrafts. The case studies include the analysis of BWR Mark III containment as a benchmark problem and analyses of Pressurised Heavy Water Reactor containment (inner and outer containment) for impulsive loading due to aircraft impact. Initially, the load is applied on outer containment wall model and subsequently the load is transferred to inner containment after the local perforation of the outer containment wall is noticed in the transient simulation. The analysis methodology evolved in the present work would be useful for studying the behavior of double containment walls and multi barrier structural configurations for aircraft impact with higher energies. The present analysis illustrates that with the provision of double containments for Indian nuclear power plants, adequate reserve strength is available for the case of an extremely low probability event of missile impact generated due to the commercial aircrafts operated in India.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1983-09-01

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

  14. Probabilistic integrity assessment of pressure tubes in an operating pressurized heavy water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Young-Jin; Park, Heung-Bae [KEPCO E and C, 188 Gumi-dong, Bundang-gu, Seongnam-si, Gyeonggi-do 463-870 (Korea, Republic of); Lee, Jung-Min; Kim, Young-Jin [School of Mechanical Engineering, Sungkyunkwan University, 300 Chunchun-dong, Jangan-gu, Suwon-si, Gyeonggi-do 440-746 (Korea, Republic of); Ko, Han-Ok [Korea Institute of Nuclear Safety, 34 Gwahak-ro, Yuseong-gu, Daejeon-si 305-338 (Korea, Republic of); Chang, Yoon-Suk, E-mail: yschang@khu.ac.kr [Department of Nuclear Engineering, Kyung Hee University, 1 Seocheon-dong, Giheung-gu, Yongin-si, Gyeonggi-do 446-701 (Korea, Republic of)

    2012-02-15

    Even though pressure tubes are major components of a pressurized heavy water reactor (PHWR), only small proportions of pressure tubes are sampled for inspection due to limited inspection time and costs. Since the inspection scope and integrity evaluation have been treated by using a deterministic approach in general, a set of conservative data was used instead of all known information related to in-service degradation mechanisms because of inherent uncertainties in the examination. Recently, in order that pressure tube degradations identified in a sample of inspected pressure tubes are taken into account to address the balance of the uninspected ones in the reactor core, a probabilistic approach has been introduced. In the present paper, probabilistic integrity assessments of PHWR pressure tubes were carried out based on accumulated operating experiences and enhanced technology. Parametric analyses on key variables were conducted, which were periodically measured by in-service inspection program, such as deuterium uptake rate, dimensional change rate of pressure tube and flaw size distribution. Subsequently, a methodology to decide optimum statistical distribution by using a robust method adopting a genetic algorithm was proposed and applied to the most influential variable to verify the reliability of the proposed method. Finally, pros and cons of the alternative distributions comparing with corresponding ones derived from the traditional method as well as technical findings from the statistical assessment were discussed to show applicability to the probabilistic assessment of pressure tubes.

  15. Level-1 probability safety assessment of the Iranian heavy water reactor using SAPHIRE software

    Energy Technology Data Exchange (ETDEWEB)

    Faghihi, F. [Department of Nuclear Engineering, School of Engineering, Shiraz University, 71348-51153 Shiraz (Iran, Islamic Republic of); Research Center for Radiation Protection, Shiraz University, Shiraz (Iran, Islamic Republic of); Nuclear Safety Research Center, Shiraz University, Shiraz (Iran, Islamic Republic of)], E-mail: faghihif@shirazu.ac.ir; Ramezani, E. [Department of Nuclear Engineering, School of Engineering, Shiraz University, 71348-51153 Shiraz (Iran, Islamic Republic of); Yousefpour, F. [Atomic Energy Organization of Iran (AEOI), Tehran (Iran, Islamic Republic of); Mirvakili, S.M. [Department of Nuclear Engineering, School of Engineering, Shiraz University, 71348-51153 Shiraz (Iran, Islamic Republic of)

    2008-10-15

    The main goal of this review paper is to analyze the total frequency of the core damage of the Iranian Heavy Water Research Reactor (IHWRR) compared with standard criteria and to determine the strengths and the weaknesses of the reactor safety systems towards improving its design and operation. The PSA has been considered for full-power state of the reactor and this article represents a level-1 PSA analysis using System Analysis Programs for Hands-On Integrated Reliability Evaluations (SAPHIRE) software. It is specifically designed to permit a listing of the potential accident sequences, compute their frequencies of occurrence and assign each sequence to a consequence. The method used for modeling the systems and accident sequences, is Large Fault Tree/Small Event Tree method. This PSA level-1 for IHWRR indicates that, based on conservative assumptions, the total frequency of accidents that would lead to core damage from internal initiating events is 4.44E-05 per year of reactor operation.

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

    International Nuclear Information System (INIS)

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

    1994-01-01

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

  17. Damage evaluation of 500 MWe Indian Pressurized Heavy Water Reactor nuclear containment for aircraft impact

    International Nuclear Information System (INIS)

    Kukreja, Mukesh

    2005-01-01

    Safety assessment of Indian nuclear containments has been carried out for aircraft impact. The loading time history for Boeing and Airbus categories of aircrafts is generated based on the principle of momentum transfer of crushable aircrafts. The case studies include the analysis of BWR Mark III containment as a benchmark problem and analyses of Pressurised Heavy Water Reactor containment (inner and outer containment) for impulsive loading due to aircraft impact. Initially, the load is applied on outer containment wall model and subsequently the load is transferred to inner containment after the local perforation of the outer containment wall is noticed in the transient simulation. The analysis methodology evolved in the present work would be useful for studying the behavior of double containment walls and multi barrier structural configurations for aircraft impact with higher energies. The present analysis illustrates that with the provision of double containments for Indian nuclear power plants, adequate reserve strength is available for the case of an extremely low probability event of missile impact generated due to the commercial aircrafts operated in India

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

    International Nuclear Information System (INIS)

    1983-06-01

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

  19. Level-1 probability safety assessment of the Iranian heavy water reactor using SAPHIRE software

    International Nuclear Information System (INIS)

    Faghihi, F.; Ramezani, E.; Yousefpour, F.; Mirvakili, S.M.

    2008-01-01

    The main goal of this review paper is to analyze the total frequency of the core damage of the Iranian Heavy Water Research Reactor (IHWRR) compared with standard criteria and to determine the strengths and the weaknesses of the reactor safety systems towards improving its design and operation. The PSA has been considered for full-power state of the reactor and this article represents a level-1 PSA analysis using System Analysis Programs for Hands-On Integrated Reliability Evaluations (SAPHIRE) software. It is specifically designed to permit a listing of the potential accident sequences, compute their frequencies of occurrence and assign each sequence to a consequence. The method used for modeling the systems and accident sequences, is Large Fault Tree/Small Event Tree method. This PSA level-1 for IHWRR indicates that, based on conservative assumptions, the total frequency of accidents that would lead to core damage from internal initiating events is 4.44E-05 per year of reactor operation

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

    International Nuclear Information System (INIS)

    Oestman, Alvar

    2002-11-01

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