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Sample records for adapted swimming pool reactor austria

  1. Backfitting swimming pool reactors

    Calculations based on measurements in a critical assembly, and experiments to disclose fuel element surface temperatures in case of accidents like stopping of primary coolant flow during full power operation, have shown that the power of the swimming pool type research reactor FRG-2 (15 MW, operating since 1967) might be raised to 21 MW within the present rules of science and technology, without major alterations of the pool buildings and the cooling systems. A backfitting program is carried through to adjust the reactor control systems of FRG-2 and FRG-1 (5 MW, housed in the same reactor hall) to the present safety rules and recommendations, to ensure FRG-2 operation at 21 MW for the next decade. (author)

  2. Core neutronics of a swimming pool research reactor

    The initial cores of the 5 MW swimming pool research reactor of the Nuclear Research Centre, Tehran have been analyzed using the computer codes METHUSELAH and EQUIPOISE. The effective multiplication factor, critical mass, moderator temperature and void coefficients of the core have been calculated and compared with vendor's values. Calculated values agree reasonably well with the vendor's results. (author)

  3. Control Rods in high-Flux Swimming-Pool Reactors

    Control-rod problems in open swimming-pool high-flux and high specific power research reactors are examined in the light of the calibrations and experiments made during the construction of the SILOE reactor. Control-rod operating experience for this reactor at 13 MW is also described. 2. The following are considered in turn: (a) Reactivity balances and reactivity values for the different types of rod tested (cadmium, B4C , rare earths and combinations of these different elements). (b) Flux peaks set up in the core by the presence of the control rods, their incidence on the specific power, the fast fluxes that can be obtained and means of increasing them. (c ) The technological problems involved in constructing the rods. (d) In-pile cooling, vibration, deformation and scram-time problems. 3. In conclusion, current studies on control rods in open swimming-pool reactors operating in the 10 - 30 1W range are briefly summarized. (author)

  4. Justify of implementation of a hot water layer system in swimming pool research reactor IEA-R1m

    The IPEN/CNEN-SP has a swimming pool research reactor (IEA-R1m) in operation since 1957 at 2 MW. In 1998, after some modifications, its nominal power increased to 5 MW. Among these modifications some adaptations had to be accomplished in the radiological protection and operational procedure. The present work aim to study the need of implementation of a hot water layer in order to reduce the dose in the workers in the vicinity of the reactor swimming pool. Applying the principles of radioprotection optimization, it was concluded that the decision of the construction of one hot water layer system in the reactor swimming pool, is not necessary. (author)

  5. Remote maintenance considerations for swimming pool tokamak reactor

    Swimming Pool Tokamak Reactor (SPTR) is one of the candidate devices which are expected to demonstrate physical and engineering feasibility for fusion power reactors. In SPTR, water shield is adopted instead of solid shield structures. Among the advantages of SPTR are, from viewpoint of remote maintenance, small handling weight and high space availability between TF coils and a vacuum vessel. On the other hand, high dose rate during reactor repair and adverse effects on remote maintenance equipment by the shielding water might be the disadvantage of SPTR, where it is assumed that the shielding water is drained during reactor repair. Since the design of SPTR is still at the preliminary stage, for remote maintenance, much effort has been directed to clarification of design conditions such as environment and handling weight. As for the remote maintenance system concepts, studies have been focussed on those for a vacuum vessel and its internal structure (blanket, divertor and protection walls) expected to be repaired more frequently. The vacuum vessel assembly is divided into 21 sectors and number of TF coils is 14. A pair of TF coils are connected with each other by antitorque beams on the whole side surface. Vacuum vessel cassettes and associated blanket, divertor and protection walls are replaced through seven windows between TF coils pairs. Therefore each vacuum vessel cassette is required moving mechanisms in toroidal and radial directions. Options for slide mechanisms are wheels, balls, rollers and water bearings. Options for driving the cassette are self-driving by hydraulic motors and external driving by rack-pinion, wires or specific vehicles. As a result of studies, the moving mechanism with wheels and hydraulic motors has been selected for the reference design, and the system with water bearings and rack-pinion as an alternative. Furthermore typical concepts have been obtained for remote maintenance equipment such as wall-mounted manipulators, tools for

  6. An analysis of postulated accident for 49-2 Swimming Pool Reactor

    The thermal hydrodynamic code RETRAN-02 is used for safety analysis of Swimming Pool Reactor. Accident of partial-loss of flow, loss of offsite electric power and unexpected reactivity insertion are analysed and discussed. These results will be helpful for operation safety of the reactor

  7. Swimming pool cleaner poisoning

    Swimming pool cleaner poisoning occurs when someone swallows this type of cleaner, touches it, or breathes in ... The harmful substances in swimming pool cleaner are: Bromine ... copper Chlorine Soda ash Sodium bicarbonate Various mild acids

  8. Swimming pool granuloma

    A swimming pool granuloma is a long-term (chronic) skin infection. It is caused by the bacteria Mycobacterium marinum . ... A swimming pool granuloma occurs when water containing Mycobacterium marinum bacteria enters a break in the skin. Signs of ...

  9. Determination of 16N and 19O activities in loop water of swimming pool reactor

    Measurements of activities for 16N and 19O nuclei in the loop water of swimming pool reactor at China Institute of Atomic Energy were carried out. In order to verify the experiment results, a calculation for same purpose was also performed. The results show their coincidence is well in uncertainty range. The evaluated recommendation data for 18O(n, γ)19O reaction cross sections are also given in the paper. (authors)

  10. Production and release of 14C from a swimming pool reactor

    The annual production rate of 14C in the Apsara swimming pool reactor works out to be about 2.94 mCi. The concentration distribution of 14C in different compartments viz. pool water, reactor hall air and ion-exchange resin ranged from 200 to 440 pCi/l, 0.09 to 0.38 pCi/l, an average concentration of 8.16 pCi/g respectively. The mean residence time of 14C in pool water is evaluated to be about 7 days taking into account various sinks. The study revealed atmospheric exchange at the air-water interface as the dominant process responsible for the loss of 14C from the pool water. (author). 7 refs., 2 figs., 4 tabs

  11. Probabilistic analysis of some safety aspects of a swimming pool reactor

    A probabilistic risk analysis of some safety aspects without the investigation of radioactivity release has been performed for the 10 MW (thermal) swimming-pool research reactor SAPHIR. Our presentation is focused on the 7 internal initiating events found to be relevant with respect to accident sequences that could result with core melt due to loss of coolant or overcriticality. The results are given by the core melt frequencies for the investigated accident sequences. It could be demonstrated by our investigation that the core melt hazard of the reactor is extremely low. (author)

  12. Effect of reactivity insertion rate on peak power and temperatures in swimming pool type research reactor

    It is essential to study the reactor behavior under different accidental conditions and take proper measures for its safe operation. We have studied the effect of reactivity insertion, with and without scram conditions, on peak power and temperatures of fuel, cladding and coolant in typical swimming pool type research reactor. The reactivity ranging from 1 $ to 2 $ and insertion times from 0.25 to 1 second have been considered. The computer code PARET has been used and results are presented in this article. (author)

  13. Conceptual design of swimming pool type tokamak power reactor (SPTR-P)

    A preliminary design study of a tokamak power reactor utilizing the deuterium/tritium/lithium fuel cycle based on a swimming pool type reactor (SPTR) concept is presented. Its primary aim is to investigate the characteristics of the swimming-pool concept in which water replaces much of the steel normally required for shielding. The major design features are: steady state operation, RF wave for plasma heating and current drive, solid tritium breeder material (Li2O), modified austenitic stainless steel as first wall and blanket structural material, pumped limiter for ash exhaust, unified assembling of blanket and vacuum vessel and pressurized water cooling. The huge and heavy solid shield structure protecting superconducting magnets which brings about great difficulties in repair and maintenance is eliminated by submerging the reactor in a water pool. The water plays a role of shielding. In addition the water shield concept reduces radioactive waste disposal and to ease radiation streaming shielding. Key design parameters are: net electric power of 1000 MW, fusion power of 3200 MW, neutron wall loading of 3.3 MW/m2, major radius of 6.9 m, plasma radius of 2.0 m, plasma elongation of 1.6, plasma current of 16 MA, total beta of 7 %, toroidal field on axis of 5.2 T. (author)

  14. Swimming Pool Safety

    ... Spread the Word Shop AAP Find a Pediatrician Safety & Prevention Immunizations All Around At Home At Play ... Español Text Size Email Print Share Swimming Pool Safety Page Content ​What is the best way to ...

  15. Application of neutron noise analysis to a swimming pool research reactor

    This work is part of a programme of establishing practical applications of neutron noise techniques to a swimming pool research reactor and deals with two different items: (1) The identification of local boiling caused e.g. by a partial blockage of the coolant flow in a fuel element. Local boiling can easily lead to a burn-out situation. The onset of boiling can be detected by neutron noise analysis and a boiling detection system is presently under development. (2) The measurement of the time evolution of the reactivity induced by xenon after reactor shut-down by an on-line reactivity meter based on neutron noise analysis. From the data, the prompt neutron decay constant at delayed critical, the equilibrium xenon reactivity worth, and an estimate of the average steady-state power flux in the core before reactor shut-down were obtained. (author)

  16. Radiation shielding considerations for the repair and maintenance of a swimming pool-type tokamak reactor

    The radiation shielding relevant to the repair and maintenance of a swimming pool-type tokamak reactor is considered. The dose rate during the reactor operation can be made low enough for personnel access into the reactor room if a 2m thick water layer is installed above the magnet cryostat. The dose rate 24 h after shutdown is such that the human access is allowed above the magnet cryostat. Sufficient water layer thickness is provided in the inboard space for the operation of automatic welder/cutter while retaining the magnet shielding capability. Some forced cooling is required for the decay heat removal in the first wall. The penetration shield thickness around the neutral beam injector port is estimated to be barely sufficient in terms of the magnet radiation damage. (orig.)

  17. Swimming Pools and Molluscum Contagiosum

    ... Travelers' Health: Smallpox & Other Orthopoxvirus-Associated Infections Poxvirus Swimming Pools Recommend on Facebook Tweet Share Compartir The ... often ask if molluscum virus can spread in swimming pools. There is also concern that it can ...

  18. A Versatile Cobalt-60 Irradiation Facility within a Swimming-Pool Research Reactor

    The IRR-1 enriched-fuel swimming-pool-type reactor incorporates a concrete-shielded gamma cell for using the radiation from spent fuel elements. A versatile 60Co irradiation facility was added at relatively low cost. The 30 000 Ci 60Co source runs on a carriage at the bottom of the reactor pool. The source plaque completely covers the aluminium window between the pool and the irradiation cell. This geometry allows for a ''source-to-target'' overlap; therefore, dose-rate homogeneity within ±20% is attained inside two commercial cases (43 x 31 x 31 cm) or two commercial sacks (80 x 45 x 45 cm) and within ±10% in two flat boxes (40 x 20 x 5 cm) irradiated simultaneously. A set of steel and aluminium screens attached to two rotating turn-tables permits irradiation of commercial cases at any desired dose-rate smaller than 100 000 R/h without the need for turning over at half-time. Two special underwater canisters allow long-term irradiation of flat specimens at dose-rates of less than 600 000 R/h, while the source is used for normal short-term irradiations in the gamma cell. Safety is ensured by a visible and audible indicator and alarm system and by an elaborate interlock system. A system of ionizing gauges and recorders permits measurement of dose-rates over the range 0. 001 to 1 000 000 R/h. Isodose curves for the irradiation chamber have been determined. The cell is soon to be modified to include a refrigeration plant and a timing system for automatic control of source movement. The disadvantages of low source utilization inherent in required source-to-target overlap and of one sided utilization of the radiation are more than compensated for by the possibility of pilot-scale irradiation of commercial cases and by the greater versatility and low cost. This installation is therefore recommended for all similar swimming-pool reactors. It is especially valuable for countries desiring to embark on a food irradiation programme at minimum cost but with maximum

  19. Temperature coefficient of reactivity of a typical swimming pool type research reactor using low enriched uranium fuel

    The temperature coefficients of reactivity of a swimming pool type material test research reactor have been calculated using standard computer codes. It is observed that the core reactivity loss due to increase in water temperature and void formation is sensitive to control rod position at criticality. The reactivity decreases more rapidly when the core volume is small. (author)

  20. Flow of kinetic parameters in a typical swimming pool type research reactor

    Iqbal, Masood [Nuclear Engineering Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan)], E-mail: masiqbal@hotmail.com; Mahmood, Tayyab; Pervez, Showket [Nuclear Engineering Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan)

    2008-03-15

    Calculations were performed to estimate the variation in kinetic parameters (delayed neutron fraction and prompt neutron generation time) in different core configurations of a typical swimming pool type research reactor. Pakistan research Reactor-1 (PARR-1) was employed for this study. The effect due to burnup of the core was also studied. Calculations were performed with the help of computer codes WIMSD/4 and CITATION. Precursors yield was modified according to the neutron flux averaging only. This is the simple way to calculate the precursor yield for a particular core. The kinetic parameters are different for different core configurations. The {beta}{sub eff} decreases with 1.33 x 10{sup -6}/% burnup whereas prompt neutron generation time increases with 6.42 x 10{sup -8} s/% burnup. The results were compared with safety analysis report and with published values and were found in good agreement. This study provides the confidence to understand the change in the kinetic parameters of research reactors with core change and also with burnup of the core.

  1. Flow of kinetic parameters in a typical swimming pool type research reactor

    Calculations were performed to estimate the variation in kinetic parameters (delayed neutron fraction and prompt neutron generation time) in different core configurations of a typical swimming pool type research reactor. Pakistan research Reactor-1 (PARR-1) was employed for this study. The effect due to burnup of the core was also studied. Calculations were performed with the help of computer codes WIMSD/4 and CITATION. Precursors yield was modified according to the neutron flux averaging only. This is the simple way to calculate the precursor yield for a particular core. The kinetic parameters are different for different core configurations. The βeff decreases with 1.33 x 10-6/% burnup whereas prompt neutron generation time increases with 6.42 x 10-8 s/% burnup. The results were compared with safety analysis report and with published values and were found in good agreement. This study provides the confidence to understand the change in the kinetic parameters of research reactors with core change and also with burnup of the core

  2. Reactor physics calculations and their experimental validation for conversion and upgrading of a typical swimming pool type research reactor

    Ali Khan, Liaquat; Ahmad, Nasir E-mail: epg.piaas@dgcc.org.pk; Zafar, M.S.; Ahmad, Ayaz

    2000-07-01

    Detailed neutronic analysis of a typical swimming pool type research reactor, Pakistan Research Reactor-1 (PARR-1), was carried out for conversion of its core from 93% highly enriched uranium to 20% low enriched uranium fuel with power upgrading from 5 to 10 MW. Standard computer codes WIMS-D/4 and CITATION were employed to calculate core excess reactivity, power defect, reactivity effect of xenon and samarium, reactivity worth of fuel element, worth of control rods, shutdown margin, reactivity feedback coefficients, neutron flux and power peaking factors. A series of low and high power tests were performed on the newly converted core to determine its performance. A comparison between the calculated and measured results is presented in this article. The agreement is generally good.

  3. Reactor physics calculations and their experimental validation for conversion and upgrading of a typical swimming pool type research reactor

    Detailed neutronic analysis of a typical swimming pool type research reactor, Pakistan Research Reactor-1 (PARR-1), was carried out for conversion of its core from 93% highly enriched uranium to 20% low enriched uranium fuel with power upgrading from 5 to 10 MW. Standard computer codes WIMS-D/4 and CITATION were employed to calculate core excess reactivity, power defect, reactivity effect of xenon and samarium, reactivity worth of fuel element, worth of control rods, shutdown margin, reactivity feedback coefficients, neutron flux and power peaking factors. A series of low and high power tests were performed on the newly converted core to determine its performance. A comparison between the calculated and measured results is presented in this article. The agreement is generally good

  4. Grundfoss: Chlorination of Swimming Pools

    Hjorth, Poul G.; Hogan, John; Andreassen, Viggo

    1998-01-01

    Grundfos asked for a model, describing the problem of mixing chemicals, being dosed into water systems, to be developed. The application of the model should be dedicated to dosing aqueous solution of chlorine into swimming pools.......Grundfos asked for a model, describing the problem of mixing chemicals, being dosed into water systems, to be developed. The application of the model should be dedicated to dosing aqueous solution of chlorine into swimming pools....

  5. 21 CFR 1250.89 - Swimming pools.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Swimming pools. 1250.89 Section 1250.89 Food and... SANITATION Sanitation Facilities and Conditions on Vessels § 1250.89 Swimming pools. (a) Fill and draw swimming pools shall not be installed or used. (b) Swimming pools of the recirculation type shall...

  6. Parametric evaluation of mixed (low and high enriched) fuel core for a swimming pool type research reactor

    Bakhtyar, S.; Iqbal, M.; Israr, M.; Pervez, S.; Salahuddin, A. [Nuclear Engineering Division, Pakistan Institute of Nuclear Science and Technology, P.O. Nilore, Islamabad (Pakistan)

    2004-07-01

    A study has been carried out to evaluate the performance of a swimming pool type research reactor core comprised of mixed (low and high enriched) uranium fuel. The study includes the calculations of core reactivity, worth of control rods and core criticality at the Beginning Of Life (BOL) of the core and for two operating conditions Cold Zero Power (CZP) and Hot Full Power (HFP). Further, to ensure safe and stable operation of the core from nuclear design point of view, average power densities in the fuel region, power peaking factors, axial power distribution in the hot channel and reactivity feed back coefficients have also been calculated. Two group fluxes have also been determined at different irradiation locations. All these calculations have been carried out employing reactor lattice code WIMS-D14 and reactor analysis code CITATION The calculated results show reasonably good agreement with the quoted operational data of the previous LEU cores. (Author)

  7. Parametric evaluation of mixed (low and high enriched) fuel core for a swimming pool type research reactor

    A study has been carried out to evaluate the performance of a swimming pool type research reactor core comprised of mixed (low and high enriched) uranium fuel. The study includes the calculations of core reactivity, worth of control rods and core criticality at the Beginning Of Life (BOL) of the core and for two operating conditions Cold Zero Power (CZP) and Hot Full Power (HFP). Further, to ensure safe and stable operation of the core from nuclear design point of view, average power densities in the fuel region, power peaking factors, axial power distribution in the hot channel and reactivity feed back coefficients have also been calculated. Two group fluxes have also been determined at different irradiation locations. All these calculations have been carried out employing reactor lattice code WIMS-D14 and reactor analysis code CITATION The calculated results show reasonably good agreement with the quoted operational data of the previous LEU cores. (Author)

  8. Safeguards in Austria

    Full text: The first IAEA routine safeguards inspection of the ASTRA reactor at the Austrian research centre at Seibersdorf near Vienna, was carried out on 2 March 1966. ASTRA is an adapted swimming pool tank type research reactor using 90 per cent enriched uranium fuel, and having a maximum capacity of about 5 MRU). It was supplied from the ISA under a bilateral agreement, in respect of which safeguarding responsibility has been transferred to the Agency. The inspection was made by O. Lendvai of Hungary and B. Sharpe of the United Kingdom. There are in Austria three research reactors under Agency safeguards, the others being respectively in Vienna and Graz. (author)

  9. Evaluation of LOCA in a swimming-pool type reactor using the 3D-AIRLOCA code

    The 3D-AIRLOCA code was used to calculate core temperature evolution curves in the wake of a full LOCA in a swimming pool type reactor, resulting in complete core exposure and dryout within about 1000 sec of the initiating event. The results show that fuel integrity loss thresholds (450 C for softening and 650 C for melting) are reached and exceeded over large fractions of the core at power levels as low as 2 MW. At 4.5 MW, the softening threshold is reached even when the accident occurs up to 12 hours after reactor shutdown for continuous operation, and up to 2 hrs after shutdown for intermittent (6 hrs/day, 4 days a week) operation. The situation is even more severe in blockage cases, when the air flow through the core is blocked by residual water at the grid plate level. It is concluded that substantial fission product releases are quite likely in this class of accidents. (orig.)

  10. Determination of neutron energy spectrum at a pneumatic rabbit station of a typical swimming pool type material test research reactor

    Malkawi, S.R.; Ahmad, N. E-mail: nasir@pieas.edu.pk

    2002-01-01

    The method of multiple foil activation was used to measure the neutron energy spectrum, experimentally, at a rabbit station of Pakistan Research Reactor-1 (PARR-1), which is a typical swimming pool type material test research reactor. The computer codes MSITER and SANDBP were used to adjust the spectrum. The pre-information required by the adjustment codes was obtained by modelling the core and its surroundings in three-dimensions by using the one dimensional transport theory code WIMS-D/4 and the multidimensional finite difference diffusion theory code CITATION. The input spectrum covariance information required by MSITER code was also calculated from the CITATION output. A comparison between calculated and adjusted spectra shows a good agreement.

  11. Determination of neutron energy spectrum at a pneumatic rabbit station of a typical swimming pool type material test research reactor

    The method of multiple foil activation was used to measure the neutron energy spectrum, experimentally, at a rabbit station of Pakistan Research Reactor-1 (PARR-1), which is a typical swimming pool type material test research reactor. The computer codes MSITER and SANDBP were used to adjust the spectrum. The pre-information required by the adjustment codes was obtained by modelling the core and its surroundings in three-dimensions by using the one dimensional transport theory code WIMS-D/4 and the multidimensional finite difference diffusion theory code CITATION. The input spectrum covariance information required by MSITER code was also calculated from the CITATION output. A comparison between calculated and adjusted spectra shows a good agreement

  12. Evaluation of LOCA in a swimming-pool type reactor using the 3D-AIRLOCA code

    The 3D-AIRLOCA code was used to calculate core temperature evolution curves in the wake of a full LOCA in a swimming pool type reactor, resulting in complete core exposure and dryout within about 1000 sec of the initiating event. The results show that fuel integrity loss thresholds (450 C for softening and 650 C for melting) are reached and exceeded over large fractions of the core at powr levels as low as 2 MW. At 4.5 MW, the softening threshold is reached even when the accident occurs up to 12 hours after reactor shutdown for continuous operation, and up to 2 hrs after shutdown for intermittent (6 hrs/day, 4 days a week) operation. The situation is even more severe in blockage cases, when the air flow through the core is blocked by residual water at the grid plate level. It is concluded that substantial fission product releases are quite likely in this class of accidents. (orig.)

  13. Calculations of partial LOCA in a swimming-pool-reactor with MTR-elements and planned mock-up experiment

    A partial uncovering of the MTR fuel plates of the swimming pool reactor SAPHIR located at the Swiss Federal Reactor Research Institute (E.I.R.) could be caused by a loss of coolant accident due to a beam tube break. The transient temperature excursions of the fuel plates during the LOCA have been predicted with computer simulations. Because a reliable prediction of the flow regime and hence the heat transfer in the uncovered part of the plate is not possible with current knowledge, a parametric study employing different heat transfer models is presented in this paper. The results show, that the heat transfer model in the uncovered part of the fuel plate has an important influence on the predicted temperatures. A mock-up experimental facility, which will supply data for the heat transfer occuring in the uncovered part, will also be described at the end of the paper. (author)

  14. Maintenance operation by divers on a swimming-pool type reactor (Osiris, CEN Saclay). Technical and medical prevention: an example of multidisciplinary ergonomic step

    Maintenance works in a swimming-pool reactor was performed by a team of divers. A multidisciplinary ergonomic study had previously defined the working procedure. The ergonomic approach is analysed. The divers' working techniques are described. After work, medical tests showed that previsions were verified and proved the methods as safe. This technique by divers' interventions should open new possibilities in nuclear industry

  15. Apparatus for irradiating in a magnetic field in a swimming pool type reactor, at high or low temperatures (1962)

    An apparatus for irradiation in a swimming-pool with a magnetic field of 5000 oersteds is described. An aluminium coil with a very high current density is water cooled. A relatively great Volume can be used in the coil center, and two furnaces can be introduced, or a liquid nitrogen cryostat. (author)

  16. Irradiations in swimming-pool type reactors from room temperature up to 2000 deg C

    The irradiations which have been, and are being carried out in the Melusine and Siloe reactors in connection with pure or applied research projects, are effected in widely varying conditions; amongst these, for example, the temperature may vary from -250 deg C to +2000 deg C The eight devices presented are designed for irradiations effected at temperatures of from room temperature up to 2000 deg C. 1. Irradiation device for irradiation at normal temperatures 2. The 'PEF' device 3. The 'CHOUCA' device, 150 to 900 deg C 4. The 'CYRANO' device for EL 4 conditions 5. 'HT' capsules, 800-1000 deg C 6. The 'HEBE' furnace 1400 deg C 7. The 'PEC' device, 1400 deg C 8. The 'HF' furnace 2000 deg C. (authors)

  17. Preliminary steps in partial decommissioning of a swimming pool type reactor Apsara: a health physics experience

    Full text: Apsara reactor after 50 years of extensive use in production of radio-isotopes, neutron radiography, neutron beam research, shielding experiments etc., is undergoing a partial decommissioning to facilitate refurbishment and up gradation to 2 MWth power using lower enriched Uranium fuel. Partial decommissioning involves defueling and removal of core components as a first step. Radiological safety in defueling is discussed in this paper. Defueling is carried out from top of pile where the radiation level was < 0.10 mR/h, under the strict stipulation that no fuel is to be lifted above water surface during transfer and hence no dose is consumed for this job. Collective dose consumed in the job was only in the SFSB area in Dhruva reactor and was 8.20 person mSv (59% of budgeted dose). This was possible by thorough mock up at Dhruva, SFSB for irradiated fuel handling, satisfying ALARA and refining the procedure. Also radiation mapping of core components, grid plate before and after removal of dry and wet guide tubes were carried out. It was observed that the top portion of grid plate showed a maximum radiation level which was 2-3 times that at bottom portion. The positions around the dry guide tubes G 1 and G 7 showed high radiation levels of 30 R/h. On removing them, the radiation levels reduced to 0.3 -0.5 R/h in all positions. This acted as an input for planning to cut and remove various core components, as also for segregation of high active/low active/inactive components from waste disposal point of view. For example the dry guide tubes G 1 and G 7 was cut and disposed as active waste with upper portion as Cat I and lower portion (was in core region) as Cat II radioactive waste

  18. Guide for decontaminating swimming pool at schools

    Because of TEPCO Fukushima Dai-ichi Nuclear Power Plant accident due to the Great East Japan Earthquake, a huge amount of radioactive materials was widely dispersed and precipitated into the environment. Swimming pools in Fukushima prefectures were contaminated with the radioactives. We JAEA carried out several demonstration tests to decontaminate the radioactives and discharge the pool water safely. We concluded the results obtained from the tests as 'Guide for decontaminating Swimming Pool at School' and released it quickly. Following this, we also released the guide in English. This manuscript, as an experimental report of the swimming pool water decontamination, is consisted from the guide in Japanese and English prepared. (author)

  19. Airways disorders and the swimming pool.

    Bougault, Valérie; Boulet, Louis-Philippe

    2013-08-01

    Concerns have been expressed about the possible detrimental effects of chlorine derivatives in indoor swimming pool environments. Indeed, a controversy has arisen regarding the possibility that chlorine commonly used worldwide as a disinfectant favors the development of asthma and allergic diseases. The effects of swimming in indoor chlorinated pools on the airways in recreational and elite swimmers are presented. Recent studies on the influence of swimming on airway inflammation and remodeling in competitive swimmers, and the phenotypic characteristics of asthma in this population are reviewed. Preventative measures that could potentially reduce the untoward effects of pool environment on airways of swimmers are discussed. PMID:23830132

  20. Next tokamak design. Swimming pool type

    In order to relieve the difficulties of repair and maintenance and to make the reactor size compact, a concept of swimming pool type reactor which is installed in a waterpool has been proposed. A design study of the concept as the Next Tokamak has been carried out with the following major parameters. The reactor has a double null poloidal divertor and blanket with tritium breeding ratio of >1.0, fusion power 420 MW, major radius 5.3 m, plasma radius 1.1 m, Bt on axis 5.2 T, plasma current 3.9 MA. The design study covers the reactor overall systems including reactor structure, reactor cooling system, repair and maintenance, reactor building, etc. As the result of this study the following conclusions were reached. The advantages over a conventional tokamak reactor are as follows: (1) The size of TF coil can be considerably reduced while retaining sufficient space for repair and maintenance because a solid shield is eliminated. (2) Since the distances between plasma and PF coils become small, the required capacity of electric power supply is reduced. (3) Technologies for the repair and maintenance are simplified and disassembling and reassembling of vacuum vessel can be done with realistic and credible remote handling technique. (4) The problem caused by radiation streaming can be considerably eased. (5) Radioactive waste disposal is reduced considerably because a solid shield is eliminated. (6) Because a vacuum vessel may be easily replaced in this concept, it will have a convenient flexibility for an experimental reactor. (7) Advantages of this concept can be also applied to a power reactor. Recently we started a new design of SPTR with slightly modified plasma parameters aiming for smaller-size reactor. In this paper the new design will be discussed briefly. (author)

  1. Strategies for chemically healthy public swimming pools

    Hansen, Kamilla Marie Speht

    overview of the strategies which can be used to achieve microbiological safe water with low levels of DBPs to ensure healthy environment for bathers. There are different approaches to achieve healthy environment in public swimming pools which in this thesis are divided into three strategies: alternatives...... to chlorination, removal of precursors and DBPs, and inhibition of the DBP formation. None of the alternative disinfection agents which are used for private swimming pools are applicable for public swimming pools. Thus chlorine is the most likely future disinfectant in public swimming pools. The...... compound which is less reactive towards chlorine. Ozone is also able to remove combined chlorine and other DBPs but the reaction is slow. Activated carbon is able to adsorb precursors and DBPs except chloramines which are removed by catalytic reaction. Formation of DBPs is unavoidable. However, the...

  2. Health risks of early swimming pool attendance.

    Schoefer, Yvonne; Zutavern, Anne; Brockow, Inken; Schäfer, Torsten; Krämer, Ursula; Schaaf, Beate; Herbarth, Olf; von Berg, Andrea; Wichmann, H-Erich; Heinrich, Joachim

    2008-07-01

    Swimming pool attendance and exposure to chlorination by-products showed adverse health effects on children. We assessed whether early swimming pool attendance, especially baby swimming, is related to higher rates of early infections and to the development of allergic diseases. In 2003-2005, 2192 children were analysed for the 6-year follow-up of a prospective birth cohort study. Data on early swimming pool attendance, other lifestyle factors and medical history were collected by parental-administered questionnaire. Bivariate and multivariate logistic regression analyses were used to evaluate associations. Babies who did not participate in baby swimming had lower rates of infection in the 1st year of life (i) diarrhoea: OR 0.68 CI 95% 0.54-0.85; (ii) otitis media: OR 0.81 CI 95% 0.62-1.05; (iii) airway infections: OR 0.85 CI 95% 0.67-1.09. No clear association could be found between late or non-swimmers and atopic dermatitis or hay fever until the age of 6 years, while higher rates of asthma were found (OR 2.15 95% CI 1.16-3.99), however, potentially due to reverse causation. The study indicates that, in terms of infections, baby swimming might not be as harmless as commonly thought. Further evidence is needed to make conclusions if the current regulations on chlorine in Germany might not protect swimming pool attendees from an increased risk of gastrointestinal infections. In terms of developing atopic diseases there is no verifiable detrimental effect of early swimming. PMID:17869580

  3. Swimming pool-induced asthma.

    Beretta, S; Vivaldo, T; Morelli, M; Carlucci, P; Zuccotti, G V

    2011-01-01

    A 13-year-old elite swimmer presented with wheezing after indoor swimming training. On the basis of her clinical history and the tests performed, exercise-induced asthma and mold-induced asthma were ruled out and a diagnosis of chlorine-induced asthma was made. PMID:21548454

  4. Research reactors in Austria - Present situation

    In the past decades Austria operated three research reactors, the 10 MW ASTRA reactor at Seibersdorf, the 250 kW TRIGA reactor at the Atominstitut and the 1 kW Argonaut reactor at the Technical University in Graz. Since the shut down of the ASTRA on July 31th, 1999 and its immediate decommissioning reactor and the shut down of the Argonaut reactor in Graz on August 31st, 2004 only one reactor remains operational for keeping nuclear competence in Austria which is the 250 kW TRIGA Mark II reactor. (author)

  5. Performance Study of Swimming Pool Heaters

    McDonald, R.J.

    2009-01-01

    The objective of this report is to perform a controlled laboratory study on the efficiency and emissions of swimming pool heaters based on a limited field investigation into the range of expected variations in operational parameters. Swimming pool heater sales trends have indicated a significant decline in the number of conventional natural gas-fired swimming pool heaters (NGPH). On Long Island the decline has been quite sharp, on the order of 50%, in new installations since 2001. The major portion of the decline has been offset by a significant increase in the sales of electric powered heat pump pool heaters (HPPH) that have been gaining market favor. National Grid contracted with Brookhaven National Laboratory (BNL) to measure performance factors in order to compare the relative energy, environmental and economic consequences of using one technology versus the other. A field study was deemed inappropriate because of the wide range of differences in actual load variations (pool size), geographic orientations, ground plantings and shading variations, number of hours of use, seasonal use variations, occupancy patterns, hour of the day use patterns, temperature selection, etc. A decision was made to perform a controlled laboratory study based on a limited field investigation into the range of expected operational variations in parameters. Critical to this are the frequency of use, temperature selection, and sizing of the heater to the associated pool heating loads. This would be accomplished by installing a limited amount of relatively simple compact field data acquisition units on selected pool installations. This data included gas usage when available and alternately heater power or gas consumption rates were inferred from the manufacturer's specifications when direct metering was not available in the field. Figure 1 illustrates a typical pool heater installation layout.

  6. Swimming Pools, Swimming pools, licensed - name, address, contact, volume, Published in 2006, Iowa Dept. of Public Health.

    NSGIC GIS Inventory (aka Ramona) — This Swimming Pools dataset, was produced all or in part from Published Reports/Deeds information as of 2006. It is described as 'Swimming pools, licensed - name,...

  7. The Cinema of the Swimming Pool

    Brown, Christopher; Hirsch, Pam

    2014-01-01

    The swimming pool frequently appears in film not merely as a setting but as a dynamic site where social, political, cultural and aesthetic forces converge. What is it about this space that has so fascinated filmmakers and what kinds of cinematic investigations does it encourage? This collection features essays by an eclectic, international range of film researchers. Amongst the works analysed are classics such as The Cameraman (1928), The Philadelphia Story (1940) and La Piscine (1969); cult ...

  8. Thermal analyses of solar swimming pool heating in Pakistan

    Hotels and swimming clubs in Pakistan pay huge gas bills for heating Swimming pools in winter. Winter days in most parts of Pakistan remain sunny and unglazed low cost solar collectors may be used to extend the swimming season. Installing the pool in a wind-protected area, which receives unobstructed solar radiation, may further reduce the size of the solar collectors required to heat the swimming pools. The pools should be covered with plastic sheet to eliminate evaporative heat losses and to prevent dust and tree leaves falling in the pool. The results of the thermal analysis show that in some parts of the country, a solar exposed pool can maintain comfortable temperature simply by using a plastic sheet on the pool surface. On the other hand, there are cities where solar collector array equal to twice the surface area of the pool is required to keep desired temperature in winter. (author)

  9. Swimming pool drownings and near-drownings among California preschoolers.

    Ellis, A A; Trent, R B

    1997-01-01

    OBJECTIVE: To describe a significant but poorly understood public health problem, the authors compiled data on swimming pool drownings and near-drownings requiring hospitalization for California children ages 1 to 4. METHODS: Data from death certificates were used to analyze swimming pool drownings, and hospital discharge data were used to analyze near-drownings. RESULTS: Among California preschoolers in 1993, pool immersion incidents were the leading cause of injury death and the eighth lead...

  10. Neutronics design of the next tokamak. (Swimming pool type)

    A swimming pool type tokamak reactor (SPTR) has been proposed in the Japan Atomic Energy Research Institute as a candidate for the next generation tokamak reactor after the JT-60. The concept of the SPTR evolved from an incentive to relieve the difficulties of repair and maintenance procedures of a tokamak reactor. After about two years of the reactor design studies, several advantages of the SPTR over the conventional tokamak reactors such as the ease of penetration shielding, reduction in solid radwaste have been shown. On the other hand, some drawbacks and uncertainties of the SPTR have also been pointed out but so far no serious defect negating the concept has been found. This paper describes the neutronics aspect of the SPTR based mostly on the result of one dimensional calculations. At first, the radiation shielding capability of water is compared with those of other candidate materials used in the blanket and shield of fusion reactors. Based on the result of the comparison and other requirements such as tritium breeding, thermal mechanical design, repair and maintenance procedures, the material arrangements of the blanket and shield are determined. The result of the blanket neutronics calculations, the radiation shielding calculations for the superconducting magnets, shutdown dose calculations are given together with major penetration shielding considerations. (author)

  11. Estimated environmental radionuclide transfer and deposition into outdoor swimming pools

    In 2011, a large radioactive discharge occurred at the Fukushima Daiichi nuclear power plant. This plant is located within a climatically temperate region where outdoor swimming pools are popular. Although it is relatively easy to decontaminate pools by refilling them with fresh water, it is difficult to maintain safe conditions given highly contaminated diurnal dust falls from the surrounding contaminated ground. Our objectives in this paper were to conduct daily radioactivity measurements, to determine the quantity of radioactive contaminants from the surrounding environment that invade outdoor pools, and to investigate the efficacy of traditional pool cleaners in removing radioactive contaminants. The depositions in the paper filterable particulates ranged from 0 to 62,5 Bq/m2/day, with the highest levels found in the southern Tohoku District containing Fukushima Prefecture and in the Kanto District containing Tokyo Metro. They were approximately correlated with the ground contamination. Traditional pool cleaners eliminated 99% of contaminants at the bottom of the pool, reducing the concentration to 41 Bq/m2 after cleaning. Authors recommended the deposition or the blown radionuclides into outdoor swimming pools must be considered into pool regulations when the environments exactly polluted with radionuclides. - Highlights: • Deposition into outdoor swimming pool in a habitable areas estimated 72 Bq/m2/day. • More than 500 Bq/m2/day deposition will exceed our national guideline (10 Bq/l) of swimming pool. • Vacuum pool cleaner eliminates 99% radionuclides deposition

  12. Allegheny County Public Swimming Pool, Hot Tub, and Spa Inspections

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Public swimming pool, hot tub, and spa facilities are licensed and inspected once each year to assure proper water quality, sanitation, lifeguard coverage and...

  13. Health impact of disinfection by-products in swimming pools.

    Villanueva, Cristina M; Font-Ribera, Laia

    2012-01-01

    This article is focused on the epidemiological evidence on the health impacts related to disinfection by-products (DBPs) in swimming pools, which is a chemical hazard generated as an undesired consequence to reduce the microbial pathogens. Specific DBPs are carcinogenic, fetotoxic and/or irritant to the airways according to experimental studies. Epidemiological evidence shows that swimming in pools during pregnancy is not associated with an increased risk of reproductive outcomes. An epidemiological study suggested an increased risk of bladder cancer with swimming pool attendance, although evidence is inconclusive. A higher prevalence of respiratory symptoms including asthma is found among swimming pool workers and elite swimmers, although the causality of this association is unclear. The body of evidence in children indicates that asthma is not increased by swimming pool attendance. Overall, the available knowledge suggests that the health benefits of swimming outweigh the potential health risks of chemical contamination. However, the positive effects of swimming should be enhanced by minimising potential risks. PMID:23247135

  14. Health impact of disinfection by-products in swimming pools

    Cristina M. Villanueva

    2012-12-01

    Full Text Available This article is focused on the epidemiological evidence on the health impacts related to disinfection by-products (DBPs in swimming pools, which is a chemical hazard generated as an undesired consequence to reduce the microbial pathogens. Specific DBPs are carcinogenic, fetotoxic and/or irritant to the airways according to experimental studies. Epidemiological evidence shows that swimming in pools during pregnancy is not associated with an increased risk of reproductive outcomes. An epidemiological study suggested an increased risk of bladder cancer with swimming pool attendance, although evidence is inconclusive. A higher prevalence of respiratory symptoms including asthma is found among swimming pool workers and elite swimmers, although the causality of this association is unclear. The body of evidence in children indicates that asthma is not increased by swimming pool attendance. Overall, the available knowledge suggests that the health benefits of swimming outweigh the potential health risks of chemical contamination. However, the positive effects of swimming should be enhanced by minimising potential risks.

  15. Health impact of disinfection by-products in swimming pools

    Villanueva, Cristina M.; Laia Font-Ribera

    2012-01-01

    This article is focused on the epidemiological evidence on the health impacts related to disinfection by-products (DBPs) in swimming pools, which is a chemical hazard generated as an undesired consequence to reduce the microbial pathogens. Specific DBPs are carcinogenic, fetotoxic and/or irritant to the airways according to experimental studies. Epidemiological evidence shows that swimming in pools during pregnancy is not associated with an increased risk of reproductive outcomes. An epidemio...

  16. Inorganic Chemical Composition of Swimming Pools in Amman-Jordan

    Bety Saqarat

    2012-10-01

    Full Text Available Monitoring was carried out during summer 2011 in three types of swimming pools in Amman-Jordan. Thirty six water samples, collected from three users type of swimming pools (adults, family and infants, were examined for its major ionic composition (HCO3-, Cl-, NO3-, SO4=, Ca+2, Mg+2, Na+, K+ and PO4+4 in addition to its BOD and COD content. All of the examined samples from the swimming pools water were acceptable according to the local and WHO standards. The type and number of users as well as the maintenance of the swimming pool water influenced the water quality. The results showed that there was a noticeable increase in NO3, PO4 and Cl than other ions. All of the examined samples from the swimming pools water were acceptable according to the local and WHO standards and although the water of the infant’s users changed frequently, it showed the highest concentration of most of the parameters and Adults’ pool showed the lowest.

  17. Device and process for recovery and disposal of radioactive wastes underwater in a swimming pool

    The device comprises a suction head and a filter fixed to a pole, for safe removing of loose parts (even brittle ones like nuclear fuel) in the core or on the bottom of the swimming pool during reactor shut down for maintenance

  18. Rotating and retractable lighting device for a swimming pool containing radioactive materials

    The lighting device is retractable under the action of appliances working in the swimming pool or thanks to various impacts. Each arm is assembled pivoting around a vertical axis. Return means as spring allow to bring back in a balanced angular position the arm carrying a headlight in a determined angular position after the arm and the headlight having been spread from this position in an intentional or fortuitous way. Application to lighting devices for nuclear reactor swimming pools. (Author). 4 figs., 3 refs

  19. Non-electric applications of pool-type nuclear reactors

    This paper recommends the use of pool-type light water reactors for thermal energy production. Safety and reliability of these reactors were already demonstrated to the public by the long-term operation of swimming pool research reactors. The paper presents the design experience of two projects: Apatity Underground Nuclear Heating Plant and Nuclear Sea-Water Desalination Plant. The simplicity of pool-type reactors, the ease of their manufacturing and maintenance make this type of a heat source attractive to the countries without a developed nuclear industry. (author). 6 figs, 1 tab

  20. Cryptosporidium and Giardia in Swimming Pools, Atlanta, Georgia

    2008-05-29

    In this podcast, Dan Rutz speaks with Dr. Joan Shields, a guest researcher with the Healthy Swimming Program at CDC, about an article in June 2008 issue of Emerging Infectious Diseases reporting on the results of a test of swimming pools in the greater Atlanta, Georgia area. Dr. Shields tested 160 pools in metro Atlanta last year for Cryptosporidium and Giardia. These germs cause most recreational water associated outbreaks.  Created: 5/29/2008 by Emerging Infectious Diseases.   Date Released: 5/29/2008.

  1. Decontamination of outdoor school swimming pools in Fukushima

    After the Fukushima Daiichi NPP accident following the Great East Japan Earthquake, many school swimming pools in Fukushima have suspended water discharge, due to concerns that pool water which contains radioactive fallout is discharged into a river or waterway for agricultural use. The Japan Atomic Energy Agency conducted researches and examinations on the existing absorbent method and the flocculation method as ways for decontaminating pool water. By reviewing and improving these methods through decontamination demonstrations at eight pools in Fukushima, a practical decontamination method for outdoor pools has been established. This report summarizes the methods and results of the decontamination demonstrations carried out at the schools. Also, the surface density of fallout estimated at one of the pools is also presented and discussed in connection with the overall collection ratio of radiocesium at the pool. (author)

  2. Acanthamoeba species in Swimming Pools of Cairo, Egypt.

    Ahmad Al-Herrawy

    2014-06-01

    Full Text Available The free-living amoebae Acanthamoeba spp. have been recognized as etiologic agents of amoebic encephalitis, keratitis, otitis, lung lesions and other skin infections mainly in immuno-compromised individuals. The purpose of this study is to detect the presence of Acanthamoeba in swimming pools in Egypt using a polymerase chain reaction (PCR method.Water samples were collected from 10 different swimming pools in Cairo, Egypt. Samples were cultured on non-nutrient agar for the detection of Acanthamoeba isolates that were confirmed by PCR amplification using genus specific primers. The molecularly confirmed Acanthamoeba isolates were morphologically identified to the species level.Members of genus Acanthamoeba were detected in 49.2% of the examined swimming-pool water samples. Morphologically, six Acanthamoeba species were isolated from the examined swimming pool water namely A. polyphaga, A.castellanii, A. rhysodes, A. mauritaniensis, A. royreba and A. triangularis. All the identified species of Acanthamoeba were molecularly confirmed to be related to the genus Acanthamoeba.The isolated species of Acanthamoeba could provoke variable degrees of infections to the swimmers. The culture method is cheaper and easier than PCR techniques that are faster for the detection of free-living amoebae.

  3. Estimated environmental radionuclide transfer and deposition into outdoor swimming pools.

    Tagami, Kazumi; Nagata, Izumi; Sueki, Keisuke

    2014-10-01

    In 2011, a large radioactive discharge occurred at the Fukushima Daiichi nuclear power plant. This plant is located within a climatically temperate region where outdoor swimming pools are popular. Although it is relatively easy to decontaminate pools by refilling them with fresh water, it is difficult to maintain safe conditions given highly contaminated diurnal dust falls from the surrounding contaminated ground. Our objectives in this paper were to conduct daily radioactivity measurements, to determine the quantity of radioactive contaminants from the surrounding environment that invade outdoor pools, and to investigate the efficacy of traditional pool cleaners in removing radioactive contaminants. The depositions in the paper filterable particulates ranged from 0 to 62,5 Bq/m(2)/day, with the highest levels found in the southern Tohoku District containing Fukushima Prefecture and in the Kanto District containing Tokyo Metro. They were approximately correlated with the ground contamination. Traditional pool cleaners eliminated 99% of contaminants at the bottom of the pool, reducing the concentration to 41 Bq/m(2) after cleaning. Authors recommended the deposition or the blown radionuclides into outdoor swimming pools must be considered into pool regulations when the environments exactly polluted with radionuclides. PMID:24878717

  4. Comprehensive Identification of Chemical DBPs from Chlorinated and Brominated Swimming Pools

    Swimming pools have been recently recognized as important routes of exposure to potentially harmful chemicals. Previous epidemiologic research has shown increased incidence of asthma and other respiratory effects for people who have significant indoor swimming pool exposures, an...

  5. Indoor swimming pool attendance and respiratory and dermal health in schoolchildren: HITEA Catalonia.

    Font-Ribera, L.; Villanueva, C.M.; Gracia-Lavedan, E.; Borràs-Santos, A.; Kogevinas, M.; Zock, J.P.

    2014-01-01

    Background: Health benefits of swimming in pools may outweigh adverse health outcomes in children, but evidence from epidemiological studies is scarce or inconclusive for different health outcomes. We evaluated the association between indoor swimming pool attendance during childhood and respiratory

  6. Swimming pool attendance and respiratory symptoms and allergies among Dutch children

    Jacobs, J.H.; Fuertes, E.; Krop, E.J.M.; Spithoven, J.; Tromp, P.; Heederik, D.J.J.

    2012-01-01

    Objectives: To describe associations among swimming, respiratory health, allergen sensitisation and Clara cell protein 16 (CC16) levels in Dutch schoolchildren. Trichloramine levels in swimming pool air were determined to assess potential exposure levels. Methods: Respiratory health and pool attenda

  7. Swimming pool attendance and respiratory symptoms and allergies among Dutch children

    Jacobs, J.H.; Fuertes, E.; Krop, E.J.M.; Spithoven, J.; Tromp, P.; Heederik, D.J.J.

    2012-01-01

    OBJECTIVES To describe associations among swimming, respiratory health, allergen sensitisation and Clara cell protein 16 (CC16) levels in Dutch schoolchildren. Trichloramine levels in swimming pool air were determined to assess potential exposure levels. METHODS Respiratory health and pool attendanc

  8. ENERGY SAVING AT OPERATION OF OUTDOOR SWIMMING POOLS

    V. F. Ivin

    2013-09-01

    Full Text Available Purpose. Energy saving is a major problem in modern power engineering and various energy-consuming devices. They include outdoor swimming pools. In order to maintain them in working condition, especially in winter period, it takes significant amount of thermal energy. Task of heat loss substantial decrease in open swimming pools is considered in the article (on DNURT example. Methodology. The method of determining the mass and heat loss on the basis of criteria equations of heat and mass transfer theory is used. Findings. Calculations of the actual DNURT pool heat loss for different seasons, as for natural convection both for air forced motion above the free water surface are performed. It is shown that for the adiabatic evaporation conditions of water from the pool in winter during blow-off with wind the heat loss can be up to 2 kW/m2 on surface. To reduce these losses it is offered to cover water surface in a pool with a special material with low thermal conductivity on the basis of porous polyethylene during the time when the pool is not used for other purposes. It is shown that the implementation of these standards will reduce the actual heat loss, at least 5-6 times. Originality. The solution of important environmental and energy problem thanks to reducing heat losses by the pool in different times of a year and correspondingly lower emissions of power generating enterprises. Practical value. It is shown that the coating surface of the pool with poorly heat-conducting and easy to install coating will let, at a minimum, to reduce the actual heat loss on 5-6 times and reduce the emissions of power plants generating energy for pool heating.

  9. Occurrence and daily variability of pharmaceuticals and personal care products in swimming pools.

    Teo, Tiffany L L; Coleman, Heather M; Khan, Stuart J

    2016-04-01

    The aim of this research was to investigate the presence and daily variability of pharmaceuticals and personal care products (PPCPs) in public swimming pools. Various types of public swimming pool water were analysed, taken from freshwater indoor swimming pools, outdoor swimming pools, spa pools and seawater swimming pools. Swimming pool water samples were analysed for 30 PPCPs using solid phase extraction (SPE) followed by isotope dilution liquid chromatography tandem mass spectrometry (LC-MS/MS). All PPCPs were below quantification limits in seawater pools. However, caffeine was detected in 12 chlorinated swimming pools at concentrations up to 1540 ng/L and ibuprofen was observed in 7 chlorinated pools at concentrations up to 83 ng/L. Caffeine and ibuprofen concentrations were below quantification limits in all fill water samples, eliminating this as their source in swimming pools. High variations in caffeine concentrations monitored throughout the day roughly reflect bather loads in swimming pools. Future monitoring of these compounds may assist in evaluating what portion of organic matter measured in swimming pools may come from human excretions. PMID:26705754

  10. Study of Fungal Contamination of Indoor Public Swimming Pools

    H Nanbakhsh

    2004-06-01

    Full Text Available Fungi are found in different environments with variable distribution patterns depending on various factors. The aim of this study was determination of fungal contaminants in public swimming pools in Uromia, Iran. The fungal contaminations of four indoor swimming pools were studied by using membrane filtration and swab sampling method. Samples were collected by a manual plastic pump, in a 200 ml sterilized bottle. All samples were collected within 2 hours and then transferred to the laboratory. A total of 384 samples including water and environmental surfaces were collected and tested for the presence of fungi in different seasons within one year. In addition to the above information, some physical and chemical parameters such as temperature, residual chlorine, pH, turbidity of water and the number of swimmers were studied. Findings indicated that, the average temperature, pH, residual chlorine and turbidity of water in the swimming pools within one year were: 29.9°C, 8.1, 0.6 ppm and 0.8 NTU respectively. The most common fungi recovered were as follows: Asepergillus Spp. 56.25%, Candida spp. 22.9%, Rhizopus spp. 4.16 %, other filamentous fungi 16.6% and other yeast species 2.8%. The fungi such as Alternaria, Cladosporium, Philophora and Trichophyton mentagrophytis were isolated from dressing room, bathing room and other places out of pools. According to these results and previous studies on pools, it has been indicated that contamination by fungi in the pools is not significant in water and environment. Presence of dermatophytic fungus from dressing room is probably due to human contact.

  11. Software for the Design of Swimming Pool Dehumidifiers Units

    Rubina, Aleš; Blasinski, Petr; Tesař, Zdeněk

    2013-06-01

    The article deals with the description and solution of physical phenomena taking place during evaporation of water. The topicality of the theme is given a number of built indoor swimming pool and wellness centers at present. In addressing HVAC systems serving these areas, it is necessary to know the various design parameters in the interior including the water temperature as the pool temperature and humidity. Following is a description of the calculation module, air handling units, including optimizing the settings of the physical changes in order to ensure the lowest energy consumption for air treatment and required maintaining internal microclimate parameters.

  12. Analysis of SBO Accident and Natural Circulation of 49-2 Swimming Pool Reactor%49-2游泳池式反应堆全场断电事故与自然循环能力分析

    吴园园; 刘天才; 孙微

    2012-01-01

    在全场断电事故下,采用RELAP5/MOD3.3程序对49-2游泳池式反应堆系统热工水力参数瞬态特性进行计算分析,验证反应堆利用自然循环和自身负反应性对事故的缓解能力,并简要讨论了堆芯通道和主泵惰转对事故后果及进程的影响.计算结果表明,在49-2反应堆发生全场断电事故且紧急停堆系统失效后,反应堆可依靠自身的负反应性使反应堆处于停堆状态,并能形成稳定的自然循环,导出堆芯余热,验证了49-2反应堆在全场断电超设计基准事故中是安全的.%The transient thermal hydraulic characteristics of 49-2 Swimming Pool Reactor (SPR) were analyzed by RELAP5/MOD3. 3 code to verify the capability of natural circulation and minus reactivity feedback for accident mitigation under the condition of station blackout (SBO). Then, the effects on accident consequence and sequence for core channels and primary pumps were briefly discussed. The calculation results show that the reactor can be shutdown by the effect of minus reactivity feedback, and the residual heat can be removed through the stable natural circulation. Therefore, it demonstrates that the 49-2 SPR is safe during the accident of SBO.

  13. Investigation on the applicability of Piety's on-line PSD-pattern recognition algorithm to boiling detection by neutron-noise at a swimming-pool reactor

    The neutron noise signal of an initiation-of-boiling experiment performed at the SAPHIR reactor has been analyzed by the PSD-pattern recognition algorithm of Piety (1977); the results indicate that the onset of boiling can be detected by this method. Improved confidence statements for the statistical decision discriminants are given. (Auth.)

  14. An Investigation on Physicochemical and Microbial Water Quality of Swimming Pools in Yazd

    M Dehvari; M Amrollahi; V Dad; MH Ehrampoush; MT Ghaneian; B Jamshidi

    2012-01-01

    Introduction: Disrespect of health regulations and proper disinfection of water and swimming pools is effective in incidence of health problems and transfer of infectious diseases to swimmers. The aim of this research was to investigate water of swimming pools in Yazd city and compare the results with national standards. Methods: In this study, 11 active covered swimming pools of Yazd city were sampled as census. Parameters of temperature, pH, amount of free and Combined chlorine residual, tu...

  15. Semi-Automatic Detection of Swimming Pools from Aerial High-Resolution Images and LIDAR Data

    Borja Rodríguez-Cuenca; Maria C. Alonso

    2014-01-01

    Bodies of water, particularly swimming pools, are land covers of high interest. Their maintenance involves energy costs that authorities must take into consideration. In addition, swimming pools are important water sources for firefighting. However, they also provide a habitat for mosquitoes to breed, potentially posing a serious health threat of mosquito-borne disease. This paper presents a novel semi-automatic method of detecting swimming pools in urban environments from aerial images and L...

  16. Quantification of continual anthropogenic pollutants released in swimming pools.

    Keuten, M G A; Peters, M C F M; Daanen, H A M; de Kreuk, M K; Rietveld, L C; van Dijk, J C

    2014-04-15

    Disinfection in swimming pools is often performed by chlorination, However, anthropogenic pollutants from swimmers will react with chlorine and form disinfection by-products (DBPs). DBPs are unwanted from a health point of view, because some are irritating, while others might be carcinogenic. The reduction of anthropogenic pollutants will lead to a reduction in DBPs. This paper investigates the continual release of anthropogenic pollutants by means of controlled sweat experiments in a pool tank during laboratory time-series experiments (LTS experiments) and also during on-site experiments (OS experiments) in a swimming pool. The sweat released during the OS and LTS experiments was very similar. The sweat rate found was 0.1-0.2 L/m(2)/h at water temperatures below 29 °C and increased linearly with increasing water temperatures to 0.8 L/m(2)/h at 35 °C. The continual anthropogenic pollutant release (CAPR) not only consisted of sweat, particles (mainly skin fragments and hair) and micro-organisms, but also sebum (skin lipids) has to be considered. The release of most components can be explained by the composition of sweat. The average release during 30 min of exercise is 250 mg/bather non-purgeable organic carbon (NPOC), 77.3 mg/bather total nitrogen (TN), 37.1 mg/bather urea and 10.1 mg/bather ammonium. The release of NPOC cannot be explained by the composition of sweat and is most probably a result of sebum release. The average release of other components was 1.31 × 10(9) # particles/bather (2-50 μm), 5.2 μg/bather intracellular adenosine triphosphate (cATP) and 9.3 × 10(6) intact cell count/bather (iCC). The pool water temperature was the main parameter to restrain the CAPR. This study showed that a significant amount of the total anthropogenic pollutants release is due to unhygienic behaviour of bathers. PMID:24530546

  17. Blanket and vacuum vessel design of the next tokamak. (Swimming pool type)

    The structural design study of a reactor module for a swimming pool type reactor (SPTR) was conducted. Since pool water plays the role of radiation shielding in the SPTR, the module does not have a solid shield. It consists of tritium breeding blankets, divertor collector plates and a vacuum vessel. The object of this study is to show the reactor module design which has a simple structure and a sufficient tritium breeding ratio. A large coverage of the plasma chamber surface with tritium breeding blanket is essential in order to obtain a high tritium breeding ratio. A breeding blanket is also placed behind the divertor collector plate, i.e. in the upper and lower region, as well as in the outboard and inboard regions of the module. A concept in which the first wall is an integral part of the blanket is employed to minimize the thickness of structural and cooling material brazed in front of the breeding material (Li2O) and to enhance the tritium breeding capability. In order to simplify the module structure the vacuum vessel and breeding blanket is also integrated in the inboard region. One of the features inherent in the swimming pool type reactor is an additional external force on the vacuum vessel, namely hydraulic pressure. A detailed structural analysis of the vacuum vessel is performed. Divertor collector plates are assemblies of co-axial tubes. They minimize the electromagnetic force on the plate induced by the plasma disruption. A thermal and structural analysis and life time estimation of the first wall and divertor collector plates are performed. (author)

  18. Bacteriological Assessment of Water Quality of Public Swimming Pools in the Accra Metropolis, Ghana

    George A. Pesewu

    2015-04-01

    Full Text Available Water is essential for life and in most parts of the world including Ghana it is used for various activities such as drinking, bathing and recreational purposes. The objective of this study was to assess the bacteriological quality of swimming pools’ water in the Accra Metropolis. Five swimming pools were selected randomly and a research team visited the pools to collect water samples and at the same time administer short questionnaires about the characteristics of the pools. The average number of swimmers, swimming bathing loads, average age group of pool users, methods of disinfection, type of chlorine used, recycling, and treatment of the water before and after use were investigated. During the visit, water samples were collected for total coliform, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus counts using the Membrane Filtration (MF method and cultured on chromogenic media. Most (60% of the selected swimming pools had a bathing load≤20 per day. The operators of the pools disinfect their pools’ water with chorine but majority (60% of the pool operators chlorinated their pools manually with powdered chlorine. The 20 water samples investigated show that 48% of swimming pools water was contaminated with S. aureus, 30.4% with Ps. aeruginosa , 20.9% with total coli form and 0.7% with E. coli. The E. coli count found in this study was very low indicating that the selected swimming pools were not feacally polluted at the time of sampling. It is recommended that future studies should use large sample sizes.

  19. Survey of bacterial contamination of environment of swimming pools in Yazd city, in 2013

    Hossein Jafari Mansoorian

    2015-09-01

    Full Text Available Background: Infections are readily transmitted as a result of bacterial contamination of swimming pools. Therefore, hygiene and preventing the contamination of swimming pools is of particular importance. The objective of this study was to determine the amount of bacterial contamination in indoor pools of Yazd in 2013. Methods: In this descriptive and analytical study, all indoor swimming pools of Yazd (12 pools were evaluated during the spring and summer of 2013, in terms of bacterial contamination. In order to determine contamination, a sterile cotton swab was used for sampling. On average, 45 samples were taken from different surfaces in each pool (shower, dressing room, sitting places in sauna, platforms and around the pool. In total, about 540 samples from all pools were tested for bacterial contamination. Results: The results show that from 540 samples, bacterial contamination was observed in about 93 samples (17.22%; and was seen more in showers, edges of the pool and jacuzzis, and the slippers used in swimming pools. The most important isolated bacteria types were E. coli, Actinobacteria, Pseudomonas alcaligenes, Pseudomonas aeruginosa and Klebsiella pneumonia. Conclusion: The results indicate the presence of bacterial contamination on the surface of these places. It is recommended that health authorities should pay more attention to cleaning and disinfecting surfaces around the pool, showers, dressing rooms etc, to prevent infectious disease transfer as a result of contact with contaminated swimming pool surfaces.

  20. Livermore pool-type reactor

    The Livermore Pool-Type Reactor (LPTR) has served a dual purpose since 1958--as an instrument for fundamental research and as a tool for measurement and calibration. Our early efforts centered on neutron-diffraction, fission, and capture gamma-ray studies. During the 1960's it was used for extensive calibration work associated with radiochemical and physical measurements on nuclear-explosive tests. Since 1970 the principal applications have been for trace-element measurements and radiation-damage studies. Today's research program is dominated by radiochemical studies of the shorter-lived fission products and by research on the mechanisms of radiation damage. Trace-element measurement for the National Uranium Resource Evaluation (NURE) program is the major measurement application today

  1. Semi-Automatic Detection of Swimming Pools from Aerial High-Resolution Images and LIDAR Data

    Borja Rodríguez-Cuenca

    2014-03-01

    Full Text Available Bodies of water, particularly swimming pools, are land covers of high interest. Their maintenance involves energy costs that authorities must take into consideration. In addition, swimming pools are important water sources for firefighting. However, they also provide a habitat for mosquitoes to breed, potentially posing a serious health threat of mosquito-borne disease. This paper presents a novel semi-automatic method of detecting swimming pools in urban environments from aerial images and LIDAR data. A new index for detecting swimming pools is presented (Normalized Difference Swimming Pools Index that is combined with three other decision indices using the Dempster–Shafer theory to determine the locations of swimming pools. The proposed method was tested in an urban area of the city of Alcalá de Henares in Madrid, Spain. The method detected all existing swimming pools in the studied area with an overall accuracy of 99.86%, similar to the results obtained by support vector machines (SVM supervised classification.

  2. Mathematical modelling and simulation of the thermal performance of a solar heated indoor swimming pool

    Mančić Marko V.

    2014-01-01

    Full Text Available Buildings with indoor swimming pools have a large energy footprint. The source of major energy loss is the swimming pool hall where air humidity is increased by evaporation from the pool water surface. This increases energy consumption for heating and ventilation of the pool hall, fresh water supply loss and heat demand for pool water heating. In this paper, a mathematical model of the swimming pool was made to assess energy demands of an indoor swimming pool building. The mathematical model of the swimming pool is used with the created multi-zone building model in TRNSYS software to determine pool hall energy demand and pool losses. Energy loss for pool water and pool hall heating and ventilation are analyzed for different target pool water and air temperatures. The simulation showed that pool water heating accounts for around 22%, whereas heating and ventilation of the pool hall for around 60% of the total pool hall heat demand. With a change of preset controller air and water temperatures in simulations, evaporation loss was in the range 46-54% of the total pool losses. A solar thermal sanitary hot water system was modelled and simulated to analyze it's potential for energy savings of the presented demand side model. The simulation showed that up to 87% of water heating demands could be met by the solar thermal system, while avoiding stagnation. [Projekat Ministarstva nauke Republike Srbije, br. III 42006: Research and development of energy and environmentally highly effective polygeneration systems based on using renewable energy sources

  3. Water treatment in public swimming pools - reduction of energy consumption; Vandbehandling i svoemmebade - reduktion af energiforbrug

    Hammerich, H.; Radisch, N. (Ramboell, Koege (Denmark)); Olesen, Jens Christian (Gladsaxe Sportscenter, Gladsaxe (Denmark)) (and others)

    2010-04-15

    Measurements were made in five public swimming baths, and energy savings were achieved using new filters, pumps, water treatment control depending on bather load, etc. In a 50 metre pool, electricity consumption for water treatment decreased by 50%, and in a hot-water/paddling pool, electricity consumption decreased by 30-40% while still maintaining satisfactory water quality - even during periods of heavy bather load. In another swimming bath, ventilation electricity consumption was reduced by 15%. The results will e.g. be used to revise the Danish executive order on swimming pools and water quality to allow bather load-dependent water circulation. (ln)

  4. Titanium distribution in swimming pool water is dominated by dissolved species

    The increased use of titanium dioxide nanoparticles (nano-TiO2) in consumer products such as sunscreen has raised concerns about their possible risk to human and environmental health. In this work, we report the occurrence, size fractionation and behavior of titanium (Ti) in a children's swimming pool. Size-fractionated samples were analyzed for Ti using ICP-MS. Total titanium concentrations ([Ti]) in the pool water ranged between 21 μg/L and 60 μg/L and increased throughout the 101-day sampling period while [Ti] in tap water remained relatively constant. The majority of [Ti] was found in the dissolved phase (<1 kDa), with only a minor fraction of total [Ti] being considered either particulate or microparticulate. Simple models suggest that evaporation may account for the observed variation in [Ti], while sunscreen may be a relevant source of particulate and microparticule Ti. Compared to diet, incidental ingestion of nano-Ti from swimming pool water is minimal. -- Highlights: •Total titanium concentrations in unfiltered swimming pool water ranged between 21 and 60 μg/L. •Evaporation of the swimming pool water is suspected of causing a temporal increase in [Ti]. •The vast majority of Ti is found in the dissolved phase (<1 kD). •Swimming pools are not a significant Ti source for human exposure via ingestion. -- In children's swimming pool water, the majority of titanium is found in the dissolved phase

  5. Bacteriological quality of some swimming pools in Alexandria with special reference to Staphylococcus aureus.

    Masoud, Ghada; Abbass, Aleya; Abaza, Amani; Hazzah, Walaa

    2016-07-01

    Swimming pools have been identified as posing some public health risks to users due to either bacterial or chemical contamination. As a result, maintaining good swimming pool water quality is an important issue in preventing health risks for bathers. This study aimed to evaluate the bacteriological quality of some swimming pools in Alexandria and to investigate the prevalence of Staphylococcus aureus (S. aureus) in water samples. A total of 120 water samples from 10 swimming pools were collected. Bacteriological analysis included heterotrophic plate count (HPC) using pour plate method; enumeration of total coliforms (TC), Escherichia coli (E. coli) and S. aureus by membrane filtration technique. Antimicrobial susceptibility testing was performed on isolated S. aureus. Residual chlorine and pH were measured at swimming pools side. HPC was the least complying microbial parameter, followed by TC. S. aureus was recovered from 18 samples; 9 isolates were methicillin resistant S.aureus (MRSA), compared to E. coli that was detected in 7 samples. HPC and TC showed statistically significant correlations with all investigated parameters. In conclusion, the examined pools showed poor quality regarding all examined parameters collectively according to the Egyptian guidelines, which necessitates implementation of proper measures to ensure safer environment in swimming pools. PMID:27312255

  6. Childhood asthma and environmental exposures at swimming pools: state of the science and research recommendations.

    Weisel, C.P.; Richardson, S.D.; Nemery, B.; Aggazzotti, G.; Baraldi, E.; Blatchley, E.R.; Blount, B.C.; Carlsen, K.H.; Eggleston, P.A.; Frimmel, F.H.; Goodman, M.; Gordon, G.; Grinshpun, S.A.; Heederik, D.J.J.; Kogevinas, M.; LaKind, J.S.; Nieuwenhuijsen, M.J.; Piper, F.C.; Sattar, S.A.

    2009-01-01

    OBJECTIVES: Recent studies have explored the potential for swimming pool disinfection by-products (DBPs), which are respiratory irritants, to cause asthma in young children. Here we describe the state of the science on methods for understanding children's exposure to DBPs and biologics at swimming p

  7. [Update of DIN 19.643--treatment and disinfection of swimming pool and bathing tub water].

    Hässelbarth, U

    1992-08-01

    German Standards Specification DIN 19,643 is at present under revision for health reasons and because of both negative and positive experiences gathered in practice. To enable adaptation of the standards specification to future developments, a Part I of the specification is being created comprising the demands to be made on the quality of the water and general demands on the construction and operation of swimming pools and tubs and basins in bath houses, e.g. in spas or municipal swimming pools. The subsequent parts of the new specification (Part 2 to Part n) concern the demands to be made on individual combinations of processes; these can be supplemented at any time in accordance with technical progress without requiring revision of the entire standards specification. Essential innovations are the reformulation of the required efficiency of disinfection, the introduction of the parameters Legionella pneumophila, trihalogen methane (THM) and the reduction of the limit value for chloramines. Technically speaking, the new features concern the automatic measurement of the auxiliary parameters of hygiene such as redox potential, pH value and free chlorine, automatic control of disinfectant additions, automatic filter rinsing with fluidization of the filter-bed to a prescribed minimum bed expansion, and the sight-glas at the filter container. The demands made on Jacuzzi and warm water spouted bed besins are integrated into the specification, thus obviating the need for German Standards Specification DIN 19,644. PMID:1392275

  8. Indoor swimming pool attendance and respiratory and dermal health in schoolchildren: HITEA Catalonia.

    Font-Ribera, L.; Villanueva, C M; Gracia-Lavedan, E.; Borràs-Santos, A.; Kogevinas, M; Zock, J. P.

    2014-01-01

    Background: Health benefits of swimming in pools may outweigh adverse health outcomes in children, but evidence from epidemiological studies is scarce or inconclusive for different health outcomes. We evaluated the association between indoor swimming pool attendance during childhood and respiratory and dermal conditions and symptoms in Catalan schoolchildren. Methods: Cross-sectional study in 2758 children aged 6–12 years from 18 primary schools in Barcelona province. Information on regular i...

  9. Swimming pool attendance is related to asthma among atopic school children: a population-based study

    Andersson, Martin; Hedman, Linnéa; Nordberg, Gunnar; Forsberg, Bertil; Eriksson, Kåre; Rönmark, Eva

    2015-01-01

    Background: By-products of water disinfectants have been suggested to cause asthma, especially in atopic children. However, studies on indoor swimming pool attendance and asthma in children have presented conflicting results. The present study examined the relationship between indoor swimming pool attendance and asthma among sensitized and non-sensitized children aged 11-12 years. Methods: An extended ISAAC questionnaire was sent to the families of all children attending fifth or sixth grade,...

  10. Childhood asthma and environmental exposures at swimming pools: state of the science and research recommendations.

    Weisel, C P; Richardson, S.D.; Nemery, B.; Aggazzotti, G.; Baraldi, E.; Blatchley, E.R.; Blount, B.C.; Carlsen, K H; Eggleston, P. A.; Frimmel, F.H.; Goodman, M.; Gordon, G.; Grinshpun, S. A.; Heederik, D.J.J.; Kogevinas, M

    2009-01-01

    OBJECTIVES: Recent studies have explored the potential for swimming pool disinfection by-products (DBPs), which are respiratory irritants, to cause asthma in young children. Here we describe the state of the science on methods for understanding children's exposure to DBPs and biologics at swimming pools and associations with new-onset childhood asthma and recommend a research agenda to improve our understanding of this issue. DATA SOURCES: A workshop was held in Leuven, Belgium, 21-23 August ...

  11. On-Line Realtime Water Quality Monitoring and Control for Swimming Pools

    Duffy, Paul; Woods, Gerard; O'Hogain, sean; Walsh, James; Caplier, C.

    2009-01-01

    Effective swimming pool water quality monitoring and control systems are important to safeguard public health and for bather comfort. Most Irish swimming pool monitoring systems rely heavily on manual methods for sampling, testing and data recording of important parameters. Microbiological testing is infrequent and results can often take days. The goal of this research is to develop a water quality monitoring and control system with real time data logging, automatic data analysis, remote moni...

  12. Swimming pool attendance and risk of asthma and allergic symptoms in children.

    Font-Ribera, L; Kogevinas, M; Zock, J-P; Nieuwenhuijsen, M J; Heederik, D; Villanueva, C M

    2009-12-01

    Increased asthma risk has been associated with pool attendance in children but evidence is inconsistent and inconclusive. A survey was conducted of 3,223 9-12-yr-old children in Sabadell (Spain) to evaluate association between swimming pool attendance and prevalence of asthma and allergic conditions and symptoms. Parents completed a questionnaire on lifetime frequency of pool attendance and symptoms in the last 12 months (wheezing, asthma medication, rhinitis and allergic rhinitis), ever having asthma and eczema, and potential confounders. Indicators of indoor and outdoor swimming pool attendance early in life, cumulatively and currently were calculated. Swimming pool attendance before the age of 2 yrs was associated with slightly lower prevalence of current asthma (OR 0.79, 95% CI 0.43-1.46), rhinitis (OR 0.86, 95% CI 0.68-1.08) and allergic rhinitis symptoms (OR 0.72, 95% CI 0.54-0.96) compared to those who started attending swimming pools after 4 yrs of age. An increased prevalence of eczema was associated with duration of lifetime pool attendance (OR 1.71, 95%CI 1.38-2.12 for >5 yrs versus 0 yrs). Swimming pool attendance in Spanish children was associated with slightly less upper and lower respiratory tract symptoms and with more eczema. Longitudinal studies are required to confirm these findings and avoid potential reverse causation. PMID:19443529

  13. Internal exposure by natural radiation and decontamination of swimming pool

    This explanation concerns the scientific knowledge and finding of the title subjects for general public to understand their present radiation environment, id est (i.e.), at about 1 year after the Fukushima Daiichi Power Plant Accident (FDPPA). The first described is the world history of radiation exposure, where A-bomb explosion in Hiroshima and Nagasaki, Three Mile Island Power Plant Accident and Chernobyl Accident are told about their teachings and about internal nuclides at FDPPA: the author points out the natural high abundance of K-40 in contrast to the release of I-131, and Cs-137/-134 in the accident. The second is described about the effect of radiations on human cells, where characteristics, measurements, unit and their derived radionuclides of alpha, beta and gamma rays are explained together with their biological influences. Also explained are hydroxy-radical formation by alpha and beta rays in the internal exposure, and comparison of external photons, gamma and more risky ultraviolet rays. Third, the author mentions about man's natural functions to protect radiation hazard. Presented are an easy calculation and a comparison of K-40 and Cs-137 contents (weight and Bq) in the body and in the swimming pool with reference to Chernobyl standards. Internal exposure by natural radionuclides like K-40 and others, is also calculated, which is found equivalent to 0.29 mSv/y based on about 5,630 Bq/60 kg body weight. Finally, explained are the knowledge and practice of decontamination, where various adsorbents like zeolite (molecular sieve), ion exchanger, charcoal and natural zeolites (alumino-silicate) are compared and the last agent, clay easily and economically available, is recommended for decontamination. Clay material is said to adsorb 87% of Cs-137 at as low level as 750 mg/L and the author has an experience to use it successfully for decontamination of the pool. Importantly, the radioactivity of the resultant sludge should not exceed 8,000 Bq/kg. (T.T.)

  14. TRR-1/M1 reactor pool refurbishment

    The pool refurbishment of the TRR-1/M1 is intended to maintain the pool and irradiation facilities in the operable condition prior to the next decade before making decision whether the reactor will be shutdown and decommissioning or used for other purposes. What ever reason the TRR-1/M1 will serve as a training tool for scientists or engineers, and isotopes production or other analytical works for a period of time until the new research reactor will be established. (orig.)

  15. OPPORTUNITIES FOR PSYCHO-MOTOR SKILLS DEVELOPMENT IN CHILDREN WITH DOWN SYNDROME - ADAPTED SWIMMING -

    Chera-Ferrario B.

    2012-12-01

    Full Text Available Sport activities have a beneficial effect on the mind and body of any type of person. The benefits of sport are even more evident in children with Down Syndrome, who exhibit a general delay in neuro-motor structures. Our aim was to develop the psycho-motor skills in children with Down Syndrome through adapted swimming exercises. We believe that our involvement in adapted swimming for children with Down Syndrome may help develop certain aspects of psycho-motor abilities. The swimming took place with 6 Down Syndrome children from the Special Needs School in Targoviste, for a period of six months and the children being assisted by volunteer students from the Valahia University Department of Sport in Targoviste.The most important result was the children's delight in coming to the pool and taking part in the swimming lessons. Through the methods and exercises used and the devoted involvement of the volunteers, the children developed great levels of trust and courage and learned to swim using only aids. After performing motor skill tests on the children, we observed a general growth in the motor skills monitored.Continuation of the adapted swimming is very important in order to mobilize the skills obtained and continue development of psycho-motor abilities.

  16. The Europeanisation of Austria: Misfit, Adaptation and Controversies

    Gerda Falkner

    2001-12-01

    Full Text Available This article analyses the multiple dimensions of Austria’s Europeanisation and the high degree of both misfit and conflict involved therein. Austria’s path to EU membership was characterised by fundamental doubts due to the country’s status of neutrality, and by a basic reinterpretation of this concept. After accession, need for institutional adaptation to the EU’s decision-making patterns was significant since major tenets of the Austrian political system are special. Furthermore, policy misfit between the domestic and the EU level was considerable in several fields, among them highly symbolic ones. Austria’s EU-related diplomacy recently witnessed a major crisis with the other 14 member states ‘sanctioning’ the new centre-right government in a controversial way. Against this background of strong and multi-dimensional misfit, Austrian performance in implementing EU law is still surprisingly good. By contrast, public appreciation of EU membership has declined even further, and a majority of Austrians oppose enlargement while the Freedom Party advocates a referendum on that issue. Therefore, the conclusions argue that improved communication processes and mutual learning across the multiple levels of the EU system are crucial.

  17. The Europeanisation of Austria: Misfit, Adaptation and Controversies

    Gerda Falkner

    2001-12-01

    Full Text Available This article analyses the multiple dimensions of Austrias Europeanisation and the high degree of both misfit and conflict involved therein. Austrias path to EU membership was characterised by fundamental doubts due to the countrys status of neutrality, and by a basic reinterpretation of this concept. After accession, need for institutional adaptation to the EUs decision-making patterns was significant since major tenets of the Austrian political system are special. Furthermore, policy misfit between the domestic and the EU level was considerable in several fields, among them highly symbolic ones. Austrias EU-related diplomacy recently witnessed a major crisis with the other 14 member states sanctioning the new centre-right government in a controversial way. Against this background of strong and multi-dimensional misfit, Austrian performance in implementing EU law is still surprisingly good. By contrast, public appreciation of EU membership has declined even further, and a majority of Austrians oppose enlargement while the Freedom Party advocates a referendum on that issue. Therefore, the conclusions argue that improved communication processes and mutual learning across the multiple levels of the EU system are crucial.

  18. Swimming pool attendance and risk of asthma and allergic symptoms in children.

    Font-Ribera, L.; Kogevinas, M.; Zock, J.P.; Nieuwenhuijsen, M.J.; Heederik, D.; Villanueva, C.M.

    2010-01-01

    Increased asthma risk has been associated with pool attendance in children but evidence is inconsistent and inconclusive. A survey was conducted of 3,223 9-12-yr-old children in Sabadell (Spain) to evaluate association between swimming pool attendance and prevalence of asthma and allergic conditions

  19. Determination of Monochloroacetic Acid in Swimming Pool Water by Ion Chromatography-Conductivity Detection

    Maria Pythias B. Espino

    2013-02-01

    Full Text Available In this study, an analytical method involving ion chromatography with conductivity detection was developed and optimized for the determination of monochloroacetic acid in swimming pool water. The ion chromatographic method has a detection limit of 0.02 mg L-1 and linear range of 0.05 to 1.0 mg L-1 with correlation coeff icient of 0.9992. The method is reproducible with percent RSD of 0.052% (n=10. The recovery of monochloroacetic acid spiked in different water types (bottled, tap and swimming pool water ranged from 28 to 122%. In dilute solutions, chloride and bromide were simultaneously analyzed along with monochloroacetic acid using the optimized method. Chloride and bromide have detection limits of 0.01 to 0.05 mg L-1, respectively. The usefulness of the ion chromatographic method was demonstrated in the analysis of monochloroacetic acid in swimming pool water samples. In such highly-chlorinated samples, an Ag/H cartridge was used prior to the ion chromatographic determination so as to minimize the signal due to chloride ion. Monochloroacetic acid was detected in concentrations between 0.020 and 0.093 mg L-1 in three of the six swimming pool water samples studied. The presence of monochloroacetic acid in the swimming pool water samples suggests the possible occurrence of other disinfection by-products in these waters.

  20. Stade NPP. Dismantling of the reactor pool

    Scharf, Daniel; Dziwis, Joachim [E.ON Anlagenservice GmbH Nukleartechnik, Gelsenkirchen (Germany); Kemp, Lutz-Hagen [KKW Stade GmbH und Co. oHG, Stade (Germany)

    2012-11-01

    Within the scope of the 4{sup th} partial decommissioning permission of Stade NPP the activated and contaminated structures of the reactor pool had to be dismantled in order to gain a completely non-radioactive reactor pool area for the subsequent clearance measurement of the reactor building. In order to achieve the aim it was intended to remove the activated pool liner sheets, its activated framework and several contaminated ventilation channels made of stainless steel, the concrete walls of the reactor pool entirely or in parts depending on their activation level, as well as the remaining activated carbon steel structures of the reactor pool bottom. Embedded in the concrete walls there were several highly contaminated excore tubes and the contaminated pool top edge, which were intended to be removed to its full extent. The contract of the Stade NPP initiated reactor pool dismantling project had been awarded to E.ON Anlagenservice GmbH (EAS) and its subsupplier sat. Kerntechnik GmbH for the concrete dismantling works and was performed as follows. In order to minimize the radiation level in the main working area in accordance with the ALARA principle, the liner sheets and middle parts of its framework were removed by means of angle grinders first, as they were the most dose rate relevant parts. As a result the primary average radiation level in the reactor pool (measured in a distance of 500 mm from the walls) was lowered from 40 {mu}Sv/h to less than 2 {mu}Sv/h. After the minimization of the radiation level in the working area the main dismantling step started with the cutting of the reactor pool walls in blocks by means of diamond rope cutters. Once a concrete block was cut out, it was transported into the fuel pool by means of a crane and crane fork, examined radiologically, marked area by area and segmented to debris by means of an electrical excavator with a hydraulic chisel. Afterwards the debris and carbon steel parts were fractioned and packed for further

  1. Stade NPP. Dismantling of the reactor pool

    Within the scope of the 4th partial decommissioning permission of Stade NPP the activated and contaminated structures of the reactor pool had to be dismantled in order to gain a completely non-radioactive reactor pool area for the subsequent clearance measurement of the reactor building. In order to achieve the aim it was intended to remove the activated pool liner sheets, its activated framework and several contaminated ventilation channels made of stainless steel, the concrete walls of the reactor pool entirely or in parts depending on their activation level, as well as the remaining activated carbon steel structures of the reactor pool bottom. Embedded in the concrete walls there were several highly contaminated excore tubes and the contaminated pool top edge, which were intended to be removed to its full extent. The contract of the Stade NPP initiated reactor pool dismantling project had been awarded to E.ON Anlagenservice GmbH (EAS) and its subsupplier sat. Kerntechnik GmbH for the concrete dismantling works and was performed as follows. In order to minimize the radiation level in the main working area in accordance with the ALARA principle, the liner sheets and middle parts of its framework were removed by means of angle grinders first, as they were the most dose rate relevant parts. As a result the primary average radiation level in the reactor pool (measured in a distance of 500 mm from the walls) was lowered from 40 μSv/h to less than 2 μSv/h. After the minimization of the radiation level in the working area the main dismantling step started with the cutting of the reactor pool walls in blocks by means of diamond rope cutters. Once a concrete block was cut out, it was transported into the fuel pool by means of a crane and crane fork, examined radiologically, marked area by area and segmented to debris by means of an electrical excavator with a hydraulic chisel. Afterwards the debris and carbon steel parts were fractioned and packed for further treatment

  2. Infant swimming in chlorinated pools and the risks of bronchiolitis, asthma and allergy.

    Voisin, C; Sardella, A; Marcucci, F; Bernard, A

    2010-07-01

    Recent studies suggest that swimming in chlorinated pools during infancy may increase the risks of lower respiratory tract infection. The aim of the present study was to assess the influence of swimming in chlorinated pools on the risks of bronchiolitis and its late consequences. A total of 430 children (47% female; mean age 5.7 yrs) in 30 kindergartens were examined. Parents completed a questionnaire regarding the child's health history, swimming practice and potential confounders. Attendance at indoor or outdoor chlorinated pools ever before the age of 2 yrs was associated with an increased risk of bronchiolitis (OR 1.68; 95% CI 1.08-2.68; p = 0.03), which was exposure-dependent for both types of pool (p-value for trend 20 h spent in chlorinated pools during infancy. Infant swimmers who developed bronchiolitis also showed higher risks of asthma and respiratory allergies later in childhood. Swimming pool attendance during infancy is associated with a higher risk of bronchiolitis, with ensuing increased risks of asthma and allergic sensitisation. PMID:20075053

  3. Swimming pool, respiratory health, and childhood asthma: should we change our beliefs?

    Uyan, Z S; Carraro, S; Piacentini, G; Baraldi, E

    2009-01-01

    Swimming is often recommended as a sport because of its several benefits to health. It is also recommended in asthmatic children as a sport with a lower potential for prompting exercise-induced asthma. However, there is growing interest in the potentially harmful effects of repeated respiratory tract exposure to chlorinated products and the problem of possible swimming-related health hazards is gaining importance at international level. It is already known that acute exposure to chlorine gas as in swimming pool accidents causes lung damage and also that elite swimmers may have increased airway inflammation and bronchial hyperreactivity, probably as a result of repeated exposure to chlorine derivatives. Recently some studies have been conducted to investigate whether repeated exposure to chlorine by-products in recreational swimmers might also lead to lung damage. In addition, some studies have been lately published on the even more debated issue of the possible harmful effects of baby swimming on respiratory health. This article reviews and discusses data from the literature on the effects of chlorine derivatives in different categories of people routinely attending swimming pools. The need for longitudinal studies is emphasized to definitely clarify any role of chlorinated swimming pool attendance in the development of asthma in recreational swimmers. PMID:19061232

  4. Disinfection by-product formation of UV treated swimming pool water

    Spiliotopoulou, Aikaterini; Hansen, Kamilla Marie Speht; Andersen, Henrik Rasmus

    2015-01-01

    Water samples from 3 indoor swimming pool facilities were tested to evaluate UV-induced effects on swimming pool water chemistry. Concentration change of several DBPs was investigated in experiments including medium pressure UV treatment with and without chlorine and post-UV chlorination. Post......-UV chlorine consumption increased, dose-dependently, with UV treatment dose. A clear absence of trihalomethane formation by UV and UV with chlorine was observed. The post-UV chlorination clearly induced formation of DBPs; however, for the total trihalomethanes (TTHM), the inductions were not more than what...... could be replicated by performing the DBP formation assay with higher chlorine concentrations to simulate extended chlorination. Post-UV chlorination of water from a swimming pool that continuously uses UV treatment to control combined chlorine could not induce secondary formation of DBPs. The...

  5. Mathematical model development of heat and mass exchange processes in the outdoor swimming pool

    M. V. Shaptala

    2014-12-01

    Full Text Available Purpose. Currently exploitation of outdoor swimming pools is often not cost-effective and, despite of their relevance, such pools are closed in large quantities. At this time there is no the whole mathematical model which would allow assessing qualitatively the effect of energy-saving measures. The aim of this work is to develop a mathematical model of heat and mass exchange processes for calculating basic heat and mass losses that occur during its exploitation. Methodology. The method for determination of heat and mass loses based on the theory of similarity criteria equations is used. Findings. The main types of heat and mass losses of outdoor pool were analyzed. The most significant types were allocated and mathematically described. Namely: by evaporation of water from the surface of the pool, by natural and forced convection, by radiation to the environment, heat consumption for water heating. Originality. The mathematical model of heat and mass exchange process of the outdoor swimming pool was developed, which allows calculating the basic heat and mass loses that occur during its exploitation. Practical value. The method of determining heat and mass loses of outdoor swimming pool as a software system was developed and implemented. It is based on the mathematical model proposed by the authors. This method can be used for the conceptual design of energy-efficient structures of outdoor pools, to assess their use of energy-intensive and selecting the optimum energy-saving measures. A further step in research in this area is the experimental validation of the method of calculation of heat losses in outdoor swimming pools with its use as an example the pool of Dnipropetrovsk National University of Railway Transport named after Academician V. Lazaryan. The outdoor pool, with water heating- up from the boiler room of the university, is operated year-round.

  6. Definition and quantification of initial anthropogenic pollutant release in swimming pools.

    Keuten, M G A; Schets, F M; Schijven, J F; Verberk, J Q J C; van Dijk, J C

    2012-07-01

    Pollutants, brought into a swimming pool by bathers, will react with chlorine to form disinfection by-products (DBPs). Some of these DBPs are found to be respiratory and ocular irritant and might be associated with asthma, or might even be carcinogenic. As DBPs in swimming pools are formed from bather-shed-pollutants, a reduction of these pollutants will lead to a reduction of DBPs. Until now, however, the release of pollutants by bathers has not been studied in detail. The study described in this paper focuses on the release of these pollutants, further called anthropogenic pollutants. The objective was to define and quantify the initial anthropogenic pollutants, by using a standardised shower cabin and a standardised showering protocol in laboratory time-series experiments and on-site experiments in swimming pools. The time-series experiments resulted in a definition of the initial anthropogenic pollutant release: the amount of pollutants released from a person in a standardised shower cabin during the first 60 s of showering. The data from the time-series experiments were used to create a model of pollutant release. The model can be used to predict the initial anthropogenic pollutant release as well as the effects of showering. On-site experiments were performed at four different swimming pools, including one outdoor pool. Results of these on-site showering experiments correspond with the time-series and model outcomes. Anthropogenic pollutant release (both chemical and microbiological) in swimming pool water can be reduced by pre-swim showering, very likely resulting in decreased DBPs formation and chlorine demand. PMID:22560894

  7. "Mappings of secrecy and disclosure": The Swimming Pool Library, the closet, and the empire.

    Dukes, T

    1996-01-01

    The Swimming Pool Library is a novel of the closet that also offers a post-colonial reading of homosexuality in contemporary culture. Through its interpretation of gay life as a dialogic between Wildean and Gidean readings of homosexuality, and its examination of the closet as what Sedgwick calls "the defining structure of gay oppression," the novel analyzes the tensions of political oppression against sexual freedom. The Swimming Pool Library is thus seen as a text in conflict with itself about the very issues it raises: closeting and gay liberation, sexual freedom and sexual responsibility, loyalty to the past and duty in the present. PMID:8895031

  8. Fungal Contamination of Indoor Public Swimming Pools, Ahwaz, South-west of Iran

    A Rafiei

    2010-09-01

    Full Text Available "nBackground: Using public swimming pools during different seasons and poor health behavior could be responsible in transmis­sion of fungal disease through pool water and its environment. Therefore, this research was conducted to investi­gate fungal agents of indoor public swimming pools of Ahwaz, capital city of Khouzestan Province, south-west of Iran."nMethods: Ten indoor swimming pools of Ahwaz were investigated during two seasons for 6 months. Water specimens were col­lected by pump and environment samples including shower-bath area, margin of pool walls, dressing rooms, and slip­pers, by sterile carpet pieces. All specimens were cultured in SC and SCC culture media and fungal agents identification were based on macroscopic, microscopic characteristic and complement tests when it was necessary. Data analyzing was per­formed using SPSS version 13 for descriptive analyzing."nResults: A total of 593 samples were collected from different parts of pools. Interestingly in 13 samples from environ­mental places, dermatophytes were isolated as follows: Trichophyton mentagrophytes, T. rubrum, T. verrucosum and Epidermo­phyton floccosum 5, 4, 3 and 1 cases respectively. Ten cases of dermatophytes were isolated from floor of dressing area. Three hundred seventy two saprophytic fungi species and 32 yeasts were recovered from water and environment sur­faces samples. Aspergillus, Penicillium and Mucor were the most common isolated saprophytic fungi."nConclusion: Existence of saprophytic fungi and yeast in pools water seems to be an indicator of their resistance to detergent agents. In addition, yeast water contamination could be from swimmers. Dermatophytes isolation from pools environment ar­eas and foot washing sink, reveals the importance of public swimming pools in disease transmission. Because dressing places are being used by all of the swimmers, take care of hygienic discipline in these places should be noted by health pol­icy markers.

  9. Monitoring organic loading to swimming pools by fluorescence excitation–emission matrix with parallel factor analysis (PARAFAC)

    Seredynska-Sobecka, Bozena; Stedmon, Colin; Boe-Hansen, Rasmus; Waul, Christopher Kevin; Arvin, Erik

    2011-01-01

    Fluorescence Excitation–Emission Matrix spectroscopy combined with parallel factor analysis was employed to monitor water quality and organic contamination in swimming pools. The fluorescence signal of the swimming pool organic matter was low but increased slightly through the day. The analysis...

  10. Modeling Target Disinfection By-Product Dynamics in Indoor Swimming Pools

    Mondal, Barnard S; Troy, Cary; Afifi, Mehrnaz; Weng, Shih-Chi; Blatchley, Ernest R.

    2013-01-01

    Chlorination is the primary disinfection method for swimming pools in the United States; however, chlorine also reacts with pollutants (e.g., sweat, urine and anthropogenic compounds) to form disinfection by-products (DBPs). Some DBPs are asthma causing (e.g. nitrogen-trichloride) and even carcinogens (e.g., trihalomethanes and nitrosamines). Consequently, exposure to DBPs poses health risks to patrons and staff in pool environments. Furthermore, volatilization of DBPs is enhanced by bather a...

  11. Heated indoor swimming pools, infants, and the pathogenesis of adolescent idiopathic scoliosis: a neurogenic hypothesis

    McMaster Marianne E

    2011-01-01

    Abstract Background In a case-control study a statistically significant association was recorded between the introduction of infants to heated indoor swimming pools and the development of adolescent idiopathic scoliosis (AIS). In this paper, a neurogenic hypothesis is formulated to explain how toxins produced by chlorine in such pools may act deleteriously on the infant's immature central nervous system, comprising brain and spinal cord, to produce the deformity of AIS. Presentation of the hy...

  12. Health-Related Behaviors in Swimming Pool Users: Influence of Knowledge of Regulations and Awareness of Health Risks

    Francesca Gallè; Laura Dallolio; Manfredo Marotta; Alessandra Raggi; Valeria Di Onofrio; Giorgio Liguori; Francesco Toni; Erica Leoni

    2016-01-01

    Background: Swimming pool attendance exposes users to infection and chemical risks that could be largely reduced with the adoption of healthy behaviors. This study aims to investigate if the knowledge of swimming pool regulations and awareness of health risks can be associated with users’ health-related behaviors. Methods: A cross-sectional study was conducted using self-administered questionnaires to collect data from two different target groups of swimming users: 184 adults and 184 children...

  13. Cancer risk assessment from exposure to trihalomethanes in tap water and swimming pool water

    PANYAKAPO Mallika; SOONTORNCHAI Sarisak; PAOPUREE Pongsri

    2008-01-01

    We investigated the concentration of trihalomethanes (THMs) in tap water and swimming pool water in the area of the Nakhon Path-om Municipality during the period April 2005-March 2006.The concentrations of total THMs,chloroform,bromodichloromethane,dibromochloromethane and bromoform in tap water were 12.70-41.74,6.72-29.19,1.12-11.75,0.63-3.55 and 0.08-3.40 μg/L,respectively,whereas those in swimming pool water were 26.15-65.09,9.50-36.97,8.90-18.01,5.19-22.78 and ND-6.56 μg/L,respectively.It implied that the concentration of THMs in swimming pool water was higher than those in tap water,particularly,brominated-THMs.Both tap water and swimming pool water contained concentrations of total THMs below the standards of the World Health Organization (WHO),European Union (EU) and the United States Environmental Protection Agency (USEPA) phase Ⅰ,but 1 out of 60 tap water samples and 60 out of 72 swimming pool water samples contained those over the Standard of the USEPA phase Ⅱ.From the two cases of cancer risk assessment including Case Ⅰ Non-Swimmer and Case Ⅱ Swimmer,assessment of cancer risk of non-swimmers from exposure to THMs at the highest and the average concentrations was 4.43×10-5 and 2.19×10-5,respectively,which can be classified as acceptable risk according to the Standard of USEPA.Assessment of cancer risk of swimmers from exposure to THMs at the highest and the average concentrations was 1.47×10-3 and 7.99×10-4,respectively,which can be classified as unacceptable risk and needs to be improved.Risk of THMs exposure from swimming was 93.9%-94.2% of the total risk.Cancer risk of THMs concluded from various routes in descending order was:skin exposure while swimming,gastro-intestinal exposure from tap water intake,and skin exposure to tap water and gastro-intestinal exposure while swimming.Cancer risk from skin exposure while swimming was 94.18% of the total cancer risk.

  14. Laboratory studies on the effect of ozonation on THM formation in swimming pool water

    Hansen, Kamilla Marie Speht; Spiliotopoulou, Aikaterini; Cheema, Waqas Akram;

    2015-01-01

    =17 min; t½,4=18 min). For drinking water, ozone decomposition was fast for the first dose of ozone (t½,1=4 min) and then decreased for the second and third dose of ozone (t½,2=19 min; t½,3=17 min). Chlorination after ozonation revealed that ozone removed reactivity of the dissolved organic carbon toward......Water samples from indoor swimming pool were ozonated at different pH values to evaluate the effect of pH on decomposition of ozone in swimming pool water. Furthermore, drinking and pool water were repeatedly ozonated followed by chlorination to evaluate THM formation. Decomposition of ozone was...... chlorine for drinking water as lower TTHM formation occurred than in non-ozonated samples. For pool water, a higher TTHM formation was observed in ozonated than non-ozonated pool water. Thus, it was observed that ozone reacts markedly different in swimming pool water from the known pattern in drinking...

  15. Swimming Pool Water Treatment Chemicals and/or Processes. Standard No. 22.

    National Sanitation Foundation, Ann Arbor, MI.

    Chemicals or processes used or intended for use, in the treatment of swimming pool water are covered. Minimum public health limits or acceptability in regard to toxicity, biocidal effectiveness, and chemical behavior and analysis are presented. The appendices give guidelines to the scientific and statistically sound evaluations to determine the…

  16. Childhood Asthma and Environmental Exposures at Swimming Pools: State of the Science and Research Recommendations

    Recent studies have explored the potential for swimming pool disinfection byproducts (DBPs) which are respiratory irritants to cause asthma in young children. While these studies raise concerns, gaps still exist in our knowledge regarding the exact causal agents and mechanisms f...

  17. Swimming Pool Hygiene: Self-Monitoring, Task Clarification, and Performance Feedback Increase Lifeguard Cleaning Behaviors

    Rose, Henry M. S.; Ludwig, Timothy D.

    2009-01-01

    The effects of task clarification, self-monitoring, and performance feedback on cleaning behaviors of 9 lifeguards in 3 performance areas (vacuuming, lobby tidying, and pool deck maintenance) were investigated using an ABA reversal design at a county swim complex. A specific task in each performance area was used as a behavioral control. Following…

  18. Photolytic removal of DBPs by medium pressure UV in swimming pool water

    Hansen, Kamilla Marie Speht; Zortea, R.; Piketty, A.;

    2013-01-01

    Medium pressure UV is used for controlling the concentration of combined chlorine (chloramines) in many public swimming pools. Little is known about the fate of other disinfection by-products (DBPs) in UV treatment. Photolysis by medium pressure UV treatment was investigated for 12 DBPs reported to...

  19. Centrifugal Pumps for Swimming Pools. National Sanitation Foundation Standard Number 17.

    National Sanitation Foundation, Ann Arbor, MI. Committee for Swimming Pool Equipment Standards.

    The pumps discussed herein are intended to be used for recirculating water in swimming pools, both public and private. Included are the basic components which may be a part of a pump such as the housing, strainer, impeller, valves, and such other parts as are attached or a part of the pump as supplied by the manufacturer. This standard is intended…

  20. Enhancing swimming pool safety by the use of range-imaging cameras

    Geerardyn, D.; Boulanger, S.; Kuijk, M.

    2015-05-01

    Drowning is the cause of death of 372.000 people, each year worldwide, according to the report of November 2014 of the World Health Organization.1 Currently, most swimming pools only use lifeguards to detect drowning people. In some modern swimming pools, camera-based detection systems are nowadays being integrated. However, these systems have to be mounted underwater, mostly as a replacement of the underwater lighting. In contrast, we are interested in range imaging cameras mounted on the ceiling of the swimming pool, allowing to distinguish swimmers at the surface from drowning people underwater, while keeping the large field-of-view and minimizing occlusions. However, we have to take into account that the water surface of a swimming pool is not a flat, but mostly rippled surface, and that the water is transparent for visible light, but less transparent for infrared or ultraviolet light. We investigated the use of different types of 3D cameras to detect objects underwater at different depths and with different amplitudes of surface perturbations. Specifically, we performed measurements with a commercial Time-of-Flight camera, a commercial structured-light depth camera and our own Time-of-Flight system. Our own system uses pulsed Time-of-Flight and emits light of 785 nm. The measured distances between the camera and the object are influenced through the perturbations on the water surface. Due to the timing of our Time-of-Flight camera, our system is theoretically able to minimize the influence of the reflections of a partially-reflecting surface. The combination of a post image-acquisition filter compensating for the perturbations and the use of a light source with shorter wavelengths to enlarge the depth range can improve the current commercial cameras. As a result, we can conclude that low-cost range imagers can increase swimming pool safety, by inserting a post-processing filter and the use of another light source.

  1. An Investigation on Physicochemical and Microbial Water Quality of Swimming Pools in Yazd

    M Dehvari

    2012-08-01

    Full Text Available Introduction: Disrespect of health regulations and proper disinfection of water and swimming pools is effective in incidence of health problems and transfer of infectious diseases to swimmers. The aim of this research was to investigate water of swimming pools in Yazd city and compare the results with national standards. Methods: In this study, 11 active covered swimming pools of Yazd city were sampled as census. Parameters of temperature, pH, amount of free and Combined chlorine residual, turbidity, alkalinity, hardness, the population of heterotrophic bacteria, Staphylococcus aureus, Pseudomonas aeruginosa, fecal streptococci, and fecal coliforms were studied. Sampling has been conducted every two weaks for 3 months and samples were analyzed under standard procedures. Results: In this research, amount of pH in 84.73%, free residual chlorine in 44.18%, Combined residual chlorine in 72.45%, alkalinity in19.82%, turbidity in 86.36%, hardness in 57.18% and temperature in 13.73% Samples were desirable. The fecal streptococci bacteria was not shown in all the swimming pools and population of heterotrophic bacteria, Staphylococcus aureus, Pseudomonas aeruginosa and fecal coliforms in 56.73%, 93.27%, 79.36% and 91.45% cases were desirable, respectively. Statistical analysis indicated that there is a direct relationship between Water turbidity and population of heterotraphic bacteria. Conclusion: According to the results, the parameters of heterotrophic bacteria population, also the alkalinity and temperature had the least compliant with the standards that shows the necessity for continuous monitoring of physical, chemical and microbial parameters and also control of filtration and disinfection of water condition of swimming pools.

  2. Health effects of disinfection by-products in chlorinated swimming pools.

    Florentin, Arnaud; Hautemanière, Alexis; Hartemann, Philippe

    2011-11-01

    Increased attendance at swimming pools is correlated with higher input of organic and minerals pollutants introduced by swimmers in the swimming pool water. In most swimming pools, microbiological control is performed by disinfection with the addition of chlorine. Chlorine is now well-known to lead to the formation of many disinfection by-products (DBPs) including trihalomethanes and chloramines. The hypothesis of a link between the presence of eye and skin irritation syndromes in swimmers and contact with swimming pool water treated with chlorine was initially proposed by Mood (1953). During recent decades many epidemiological studies have described the importance of DBPs generated with natural or imported organic matter present in water. Many of these DBPs are suspected to be toxic or even carcinogenic. Trihalomethanes and haloacetic acid families are the most studied but others DBPs, like chloral hydrate, haloacetonitriles, N-nitrosodimethylamine and the bromate ion, are emerging compounds of interest. Epidemiological data about the risk of cancer are still controversial. However, numerous publications highlight a toxic risk especially the risk of allergy and respiratory symptoms for babies and elite swimmers. The few publications dedicated to risk assessment do not suggest increased risk, other than for elite swimmers. These publications are likely to underestimate the risk associated with DBPs because of the lack of data in the literature precludes the calculation of risk associated with certain compounds or certain pathways. Thus for regulations, the need to take into account the risks associated with disinfection by-products is now important without forgetting the need of the control of microbiological hazards in swimming pools. PMID:21885333

  3. THE ASSESSMENT OF THE PUBLIC SWIMMING POOLS FOR THE PURPOSES OF THE LİFEGUARD SERVICE

    Gundogdu, Cemal

    2008-01-01

    In this study, the case of selection and education of the lifeguards at public pools is studied. For this purpose, the control list related to the lifeguard education and selection in total 80 swimming pools,olympic-semi olympic,open and closed, that are used for sportive purposes belonging to Youth and Sport General Directorship and Local adminstration," was filled by the natural observations and face to face contact technics. As a result, it is found that, the pools in Turkey are n...

  4. Photolytic removal of DBPs by medium pressure UV in swimming pool water

    Medium pressure UV is used for controlling the concentration of combined chlorine (chloramines) in many public swimming pools. Little is known about the fate of other disinfection by-products (DBPs) in UV treatment. Photolysis by medium pressure UV treatment was investigated for 12 DBPs reported to be found in swimming pool water: chloroform, bromodichloromethane, dibromochloromethane, bromoform, dichloroacetonitrile, bromochloroacetonitrile, dibromoacetronitrile, trichloroacetonitrile, trichloronitromethane, dichloropropanone, trichloropropanone, and chloral hydrate. First order photolysis constants ranged 26-fold from 0.020 min−1 for chloroform to 0.523 min−1 for trichloronitromethane. The rate constants generally increased with bromine substitution. Using the UV removal of combined chlorine as an actinometer, the rate constants were recalculated to actual treatment doses of UV applied in a swimming pool. In an investigated public pool the UV dose was equivalent to an applied electrical energy of 1.34 kWh m−3 d−1 and the UV dose required to removed 90% of trichloronitromethane was 0.4 kWh m−3 d−1, while 2.6 kWh m−3 d−1 was required for chloral hydrate and the bromine containing haloacetonitriles and trihalomethanes ranged from 0.6 to 3.1 kWh m−3 d−1. It was predicted thus that a beneficial side-effect of applying UV for removing combined chlorine from the pool water could be a significant removal of trichloronitromethane, chloral hydrate and the bromine containing haloacetonitriles and trihalomethanes. - Highlights: ► UV irradiation is able to degrade all 12 investigated disinfection by-products. ► Bromine species are easier to remove than their chlorinated analogues. ► UV dose used for combined chlorine was comparable with doses required for DBP removal. ► Significant removal of some disinfection by-products in swimming pools is indicated

  5. What’s in the Pool? A Comprehensive Identification of Disinfection By-Products and Assessment of Mutagenicity of Chlorinated and Brominated Swimming Pool Water

    Swimming pool disinfectants and disinfection by-products (DBPs) have been linked to human health effects, including asthma and bladder cancer, but no studies have provided a comprehensive identification of DBPs in pool water and related those DBPs to the mutagenicity of pool wate...

  6. Microflora of nuclear research reactor pool water

    The circulation of pool water through the nuclear reactor core produces a bactericidal effect on the microflora due to the influence of various kinds of radiation. The microbe contents return to their initial level in 2 to 4 months after the circulation has stopped. The microflora comprises mainly cocci in large numbers, G-positive rods and fungi, and lower amounts of G-negative rods as compared with the water with which the reactor pool was initially filled. Increased amounts are present of radiation-resistant forms exhibiting intense production of catalase and nuclease. Supposedly, the presence of these enzymes is in some way beneficial to the microbes in their survival in the high-radiation zones. (author). 1 fig., 2 tabs., 12 refs

  7. What’s in the Pool? A Comprehensive Identification of Disinfection By-Products and Assessment of Mutagenicity of Chlorinated and Brominated Swimming Pool Water

    Richardson, S.D.; Demarini, D.M.; Kogevinas, M; Fernandez, P.; Marco, E.; Lourencetti, C.; Balleste, C.; Heederik, D; Meliefste, K.; McKague, A.B.; Marcos, R.; Font-Ribera, L.; J.O. Grimalt; Villanueva, C M

    2010-01-01

    BACKGROUND: Swimming pool disinfectants and disinfection by-products (DBPs) have been linked to human health effects, including asthma and bladder cancer, but no studies have provided a comprehensive identification of DBPs in the water and related that to mutagenicity. OBJECTIVES: We performed a comprehensive identification of DBPs and disinfectant species in waters from public swimming pools in Barcelona, Catalonia, Spain, that disinfect with either chlorine or bromine, and we determined the...

  8. Swimming Pools, File name = RECREATION. Swimming pools are a portion of this dataset. http://www.harfordcountymd.gov/gis/Index.cfm, Published in 2007, 1:1200 (1in=100ft) scale, Harford County Government.

    NSGIC GIS Inventory (aka Ramona) — This Swimming Pools dataset, published at 1:1200 (1in=100ft) scale, was produced all or in part from Orthoimagery information as of 2007. It is described as 'File...

  9. Particles in swimming pool filters – Does pH determine the DBP formation?

    Hansen, Kamilla Marie Speht; Willach, Sarah; Mosbæk, Hans;

    2012-01-01

    countries, and the non-regulated haloacetic acids (HAAs) and haloacetonitriles (HANs) were investigated at 6.0⩽pH⩽8.0, under controlled chlorination conditions. The investigated particles were collected from a hot tub with a drum micro filter. In two series of experiments with either constant initial active......The formation was investigated for different groups of disinfection byproducts (DBPs) during chlorination of filter particles from swimming pools at different pH-values and the toxicity was estimated. Specifically, the formation of the DBP group trihalomethanes (THMs), which is regulated in many...... or initial free chlorine concentrations the particles were chlorinated at different pH-values in the relevant range for swimming pools. THM and HAA formations were reduced by decreasing pH while HAN formation increased with decreasing pH. Based on the organic content the relative DBP formation from...

  10. Efficiency of heat pump ventilation and water heating system in an indoor swimming pool

    Безродний, Михайло Костянтинович; Кутра, Дмитро Сергійович; Морощук, Олександр Олександрович

    2014-01-01

    The thermodynamic efficiency of the heat pump ventilation and water heating system of indoor swimming pool with partial exhaust air recirculation and heat pump bypass is analyzed in the paper. The purpose of the work is to determine the system efficiency depending on the change of fresh supply air temperature, ventilation system intensity and heat pump bypassing factor. As a result of implementing the developed mathematical model using the method of successive approximations, dependences of t...

  11. Pulmonary Epithelial Integrity in Children: Relationship to Ambient Ozone Exposure and Swimming Pool Attendance

    Lagerkvist, Birgitta Json; Bernard, Alfred; Blomberg, Anders; Bergstrom, Erik; Forsberg, Bertil; Holmstrom, Karin; Karp, Kjell; Lundstrom, Nils-Goran; Segerstedt, Bo; Svensson, Mona; Nordberg, Gunnar

    2004-01-01

    Airway irritants such as ozone are known to impair lung function and induce airway inflammation. Clara cell protein (CC16) is a small anti-inflammatory protein secreted by the nonciliated bronchiolar Clara cells. CC16 in serum has been proposed as a noninvasive and sensitive marker of lung epithelial injury. In this study, we used lung function and serum CC16 concentration to examine the pulmonary responses to ambient O3 exposure and swimming pool attendance. The measurements were made on 57 ...

  12. New method for determination of trihalomethanes in exhaled breath: Applications to swimming pool and bath environments

    A method for the estimation of the human intake of trihalomethanes (THMs), namely chloroform, bromodichloromethane, dibromochloromethane and bromoform, during showering and bathing is reported. The method is based on the determination of these compounds in exhaled breath that is collected by solid adsorption on Tenax using a device specifically designed for this purpose. Instrumental measurements were performed by automatic thermal desorption coupled to gas chromatography with electron capture detection. THMs in exhaled breath samples were determined during showering and swimming pool attendance. The levels of these compounds in indoor air and water were also determined as reference for interpretation of the exhaled breath results. The THM concentrations in exhaled breath of the volunteers measured before the exposure experiments showed a close correspondence with the THMs levels in indoor air where the sampler was located. Limits of detection in exhaled breath were dependent on THM analytes and experimental sites. They ranged between 170 and 710 ng m-3 in the swimming pool studies and between 97 and 460 ng m-3 in the showering studies. Application of this method to THMs determination during showering and swimming pool activities revealed statistically significant increases in THMs concentrations when comparing exhaled breath before and after exposure.

  13. Surveillance and risk management in public swimming pools

    Pascal Lebihain; Elie Vignac

    2014-01-01

    La France compte aujourd’hui plus de 4500 piscines publiques (PP), ou privées d’accès payant, réparties sur son territoire, qui fournissent le plus souvent des services de qualité orientés sur l’apprentissage de la natation, la détente, le sport ou encore la forme. D’un point de vue systémique, ces équipements comptent de nombreux acteurs tant internes qu’externes, usagers, professionnels ou bénévoles, qui tentent tous de s’adapter à leur complexité croissante. Dans une société de plus en plu...

  14. Prevalence of Ocular, Respiratory and Cutaneous Symptoms in Indoor Swimming Pool Workers and Exposure to Disinfection By-Products (DBPs)

    Guglielmina Fantuzzi; Elena Righi; Guerrino Predieri; Pierluigi Giacobazzi; Katia Mastroianni; Gabriella Aggazzotti

    2010-01-01

    The objective of this cross-sectional study was to investigate the prevalence of self-reported respiratory, ocular and cutaneous symptoms in subjects working at indoor swimming pools and to assess the relationship between frequency of declared symptoms and occupational exposure to disinfection by-products (DBPs). Twenty indoor swimming pools in the Emilia Romagna region of Italy were included in the study. Information about the health status of 133 employees was collected using a self-adminis...

  15. Photolytic removal of DBPs by medium pressure UV in swimming pool water

    Hansen, Kamilla M.S. [Department of Environmental Engineering, Technical University of Denmark (Denmark); Zortea, Raissa [Department of Land, Environment and Geotechnology Engineering, Polytechnic University of Turin (Italy); Piketty, Aurelia [Institute of Chemistry, Industrial and Chemical Engineering and Technology (INP-ENCIACET), National Polytechnic Institute of Toulouse (France); Vega, Sergio Rodriguez [Chemical Engineering, Complutense University of Madrid (Spain); Andersen, Henrik Rasmus, E-mail: Henrik@ndersen.net [Department of Environmental Engineering, Technical University of Denmark (Denmark)

    2013-01-15

    Medium pressure UV is used for controlling the concentration of combined chlorine (chloramines) in many public swimming pools. Little is known about the fate of other disinfection by-products (DBPs) in UV treatment. Photolysis by medium pressure UV treatment was investigated for 12 DBPs reported to be found in swimming pool water: chloroform, bromodichloromethane, dibromochloromethane, bromoform, dichloroacetonitrile, bromochloroacetonitrile, dibromoacetronitrile, trichloroacetonitrile, trichloronitromethane, dichloropropanone, trichloropropanone, and chloral hydrate. First order photolysis constants ranged 26-fold from 0.020 min{sup −1} for chloroform to 0.523 min{sup −1} for trichloronitromethane. The rate constants generally increased with bromine substitution. Using the UV removal of combined chlorine as an actinometer, the rate constants were recalculated to actual treatment doses of UV applied in a swimming pool. In an investigated public pool the UV dose was equivalent to an applied electrical energy of 1.34 kWh m{sup −3} d{sup −1} and the UV dose required to removed 90% of trichloronitromethane was 0.4 kWh m{sup −3} d{sup −1}, while 2.6 kWh m{sup −3} d{sup −1} was required for chloral hydrate and the bromine containing haloacetonitriles and trihalomethanes ranged from 0.6 to 3.1 kWh m{sup −3} d{sup −1}. It was predicted thus that a beneficial side-effect of applying UV for removing combined chlorine from the pool water could be a significant removal of trichloronitromethane, chloral hydrate and the bromine containing haloacetonitriles and trihalomethanes. - Highlights: ► UV irradiation is able to degrade all 12 investigated disinfection by-products. ► Bromine species are easier to remove than their chlorinated analogues. ► UV dose used for combined chlorine was comparable with doses required for DBP removal. ► Significant removal of some disinfection by-products in swimming pools is indicated.

  16. Ecology of dermatophytes and other keratinophilic fungi in swimming pools and polluted and unpolluted streams.

    Ali-Shtayeh, M S; Khaleel, Tayseer Kh M; Jamous, Rana M

    2002-01-01

    The biodiversity and richness of keratinophilic fungal communities including dermatophytes were assessed in three stream sites and three swimming pools in the Nablus district in Palestine, using hair baiting (HBT) and surface dilution plate (SDP) techniques, over 8- and 6-month periods, respectively. The effect of wastewater effluent and selected ecological factors on these fungi in relation to species diversity and population densities were also considered. Fifty keratinophilic fungal species were recovered from the aquatic habitats studied, of which 42 were recovered from stream sites and 22 from swimming pools. Of these fungi 6 were either dermatophytes (Microsporum gypseum, and Trichophyton mentagrophytes) or dermatophyte related species (Chrysosporium merdarium, Ch. tropicum, Ch. keratinophilum and T. terrestre). The most frequently isolated species in the three pools were Acremonium strictum and Cladosporium cladosporioides, using Sabouraud dextrose agar medium (SDA). The most abundant species were Acr. strictum, and Aspergillus flavus. However, only 4 species were isolated using the SDA medium amended with 5-flurocytosine (5-FC). The most frequent and abundant species in the three stream sites using SDA medium were Geotricum candidum, and Penicillium chrysogenum. The most frequent species in the three sites using the 5-FC medium, was Paecilomyces lilacinus. Using HBT, the most abundant and frequent species in the three stream sites were G. candidum, and Pa. lilacinus, on SDA medium, and Pa. lilacinus, and Gliocladium nigrovirens on the 5-FC medium. The 5-FC medium was more suitable for the isolation of dermatophytes and closely related species than the SDA medium; 6 were recovered on 5-FC, whereas only one on the SDA medium. Variation in the levels of keratinophilic fungal populations from the three stream sites sampled 5 times over an 8-month period, followed comparable fluctuation patterns. Wastewater affected fungal population densities with the highest

  17. Determining a pool - type reactor fuel policy

    Refuelling the 10 to 15 MW pool type reactor considered here will occur frequently (some 10 elements every 3 to 4 weeks). It is therefore necessary to determine the most economic fuel policy. This study proposes to define a strategy that will make it possible to decide on the number and characteristics of the shipment containers, as well as on the means of storage, so as to reduce the risks as much as possible should the basic parameters of the study vary. Among these parameters, the respective influence of which is investigated, chemical reprocessing costs play a vital part. Two examples of optimum fuel management are given according to whether the reprocessing charges applied are those of the old or of the 1961 U.S. AEC base charges for reprocessing highly enriched irradiated fuel. (authors)

  18. Temporal change of radiocesium level in the school swimming pools in Kawamata after Fukushima nuclear accident

    A tremendous amount of radioactive nuclides were released into the environment due to the accident at the Fukushima Daiichi Nuclear Power Plant. In order to understand the behavior of these radioactive nuclides, we have investigated radiocesium level in the school swimming pools in Kawamata away about 40 km from the Fukushima Nuclear Power Plant. Water samples were collected on April 30, July 27, and November 9, 2011. These samples were absorbed to ion exchange resin and measured with a Ge semiconductor detector at ICRR, the University of Tokyo for 134Cs(2.06 y) and 137Cs(30.07 y). Change of ratio and concentration of these radiocesium few months after the accident were examined. We also examined the changes of ratio and concentration before and after the replacement of the pools water. The result of the measurements will be reported with review of relevant literatures. (author)

  19. Isolation and identification of Acanthamoeba spp. from thermal swimming pools and spas in Southern Brazil.

    Fabres, Laura Fuhrich; Rosa Dos Santos, Sayonara Peixoto; Benitez, Lisianne Brittes; Rott, Marilise Brittes

    2016-06-01

    Free-living amoebae (FLA) are widely distributed in soil and water. A few number of them are implicated in human disease: Acanthamoeba spp., Naegleria fowleri, Balamuthia mandrillaris and Sappinia diploidea. Species of Acanthamoeba can cause keratitis and brain infections. In this study, 72 water samples were taken from both hot tubs and thermal swimming pools in the city of Porto Alegre, RS, Brazil, to determine the presence of Acanthamoeba in the water as well as perform the phenotypic and genotypic characterization of the isolates. The identification of the isolates was based on the cysts morphology and PCR amplification using genus-specific oligonucleotides. When the isolates were submitted to PCR reaction only 8 were confirmed as belonging to the genus Acanthamoeba. The sequences analysis when compared to the sequences in the GenBank, showed genotype distribution in group T3 (12,5%), T5 (12,5%), T4 (25%) and T15 (50%). The results of this study confirmed the presence of potentially pathogenic isolates of free living amoebae in hot swimming pool and spas which can present risks to human health. PMID:27078644

  20. A survey of fungi and some indicator bacteria in chlorinated water of indoor public swimming pools

    Aho, R.; Hirn, J.

    1981-01-01

    Fifty-four water samples, of volume 500 ml, originating from six public indoor fresh water swimming pools were examined for the presence of fungi and some indicator bacteria by a membrane-filter method. Sabouraud-dextrose agar and selective Candida albicans-medium were used for isolation and identification of fungi. In all but one of the samples the free chlorine content was above 0.40 mg/l. No Candida albicans were detected. Molds and unidentified yeasts were isolated from 29 of the samples. The following species were recorded: Acremonium spp., ALternaria sp., Aspergillus spp., Candida guilliermondii, Chaetomium sp., Cladosporium spp., Clasterosporium sp., Fusarium spp., Geotrichium sp., Penicillium spp., Petriellidium boydii and Phoma spp. Their occurrence was sporadic, each species mostly appearing as single colonies only, with a maximum of 5 colonies. Bacterial growth was noticed in 15 samples, but only in the sample of low free chlorine content did this reach significant proportions. The study indicates that the standard of chlorination is, at least in general, an adequate measure against fungal contamination of swimming pool water. However, the spectrum of mold species encountered encourages a further search for possible indicator species among these organisms.

  1. Autonomic adaptation after traditional and reverse swimming training periodizations.

    Clemente-Suárez, Vicente Javier; Fernandes, R J; Arroyo-Toledo, J J; Figueiredo, P; González-Ravé, J M; Vilas-Boas, J P

    2015-03-01

    The objective of the present study was to analyze the autonomic response of trained swimmers to traditional and reverse training periodization models. Seventeen swimmers were divided in two groups, performing a traditional periodization (TPG) or a reverse periodization (RPG) during a period of 10 weeks. Heart rate variability and 50 m swimming performance were analyzed before and after the training programs. After training, the TPG decreased the values of the high frequency band (HF), the number of differences between adjacent normal R-R intervals longer than 50 ms (NN50) and the percentage of differences between adjacent normal R-R intervals more than 50 ms (pNN50), and the RPG increased the values of HF and square root of the mean of the sum of the squared differences between adjacent normal R-R intervals (RMSSD). None of the groups improved significantly their performance in the 50-m test. The autonomic response of swimmers was different depending on the periodization performed, with the reverse periodization model leading to higher autonomic adaption. Complementary, the data suggests that autonomic adaptations were not critical for the 50-m swimming performance. PMID:25804392

  2. What's in The Pool? A Comprehensive Identification Of Disinfection By-Products and Assessment of Mutagenicity of Chlorinated and Brominated Swimming Pool Water

    Swimming pool disinfectants and disinfection by-products (DBPs) have been linked to human health effects, including asthma and bladder cancer, but no studies have provided a comprehensive identification of DBPs in the water and related that to mutagenicity. We performed a compreh...

  3. What's in the pool? A comprehensive identification of disinfection by-products and assessment of mutagenicity of chlorinated and brominated swimming pool water

    Richardson, S.D.; Demarini, D.M.; Kogevinas, M.; Fernandez, P.; Marco, E.; Lourencetti, C.; Balleste, C.; Heederik, D.; Meliefste, K.; McKague, A.B.; Marcos, R.; Font-Ribera, L.; Grimalt, J.O.; Villanueva, C.M.

    2010-01-01

    BACKGROUND: Swimming pool disinfectants and disinfection by-products (DBPs) have been linked to human health effects, including asthma and bladder cancer, but no studies have provided a comprehensive identification of DBPs in the water and related that to mutagenicity. OBJECTIVES: We performed a com

  4. Comparison of swimming pools alternative passive and active heating systems based on renewable energy sources in Southern Europe

    This article examines different passive and active heating systems for swimming pools. The passive systems introduced in this article are: * The swimming pools' enclosure. * The placement of floating insulating covers on the pools' surfaces whenever they are not used. The examined active systems in this article are: * A biomass heater. * A biomass heater and solar collectors combi-system. * Vertical geothermal heat exchangers (GHE) co-operating with geothermal heat pumps (GHP). The methodology employed for the introduced systems' evaluation is the arithmetic computational simulation of the swimming pools' annual heating, using annual time series of averaged hourly values for the available solar radiation and the calculated pools' thermal power demand (heating loads). The dimensioning of the active systems aims at the maximisation of the heating production from R.E.S. (renewable energy sources). and the optimisation of the corresponding investments' economic indexes. The examined systems are evaluated technically and economically versus fundamental criteria. It is proved that significant reduction of the heating loads is achieved with the introduced passive systems. The reduced swimming pools' heating loads can be successfully covered by the proposed R.E.S. active systems. The fossil fuels consumption is eliminated. The corresponding investments' payback periods can be lower than 5 years. - Highlights: • The passive solar systems reduce the swimming pools heating loads more than 90%. • The examined active heating system exhibit payback periods lower than 3.5 years. • The energy saving is maximised with a biomass heater – solar collectors system. • Single biomass heaters exhibits the shortest payback period. • GHE–GHP can be used in cases of low solar radiation and lack of biomass fuels

  5. Secondary formation of disinfection by-products by UV treatment of swimming pool water

    Spiliotopoulou, Aikaterini [Water ApS, Farum Gydevej 64, 3520 Farum (Denmark); Department of Environmental Engineering, Technical University of Denmark, Miljøvej, Building 113, 2800 Kongens Lyngby (Denmark); Hansen, Kamilla M.S., E-mail: kmsh@env.dtu.dk [Department of Environmental Engineering, Technical University of Denmark, Miljøvej, Building 113, 2800 Kongens Lyngby (Denmark); Andersen, Henrik R. [Department of Environmental Engineering, Technical University of Denmark, Miljøvej, Building 113, 2800 Kongens Lyngby (Denmark)

    2015-07-01

    Formation of disinfection by-products (DBPs) during experimental UV treatment of pool water has previously been reported with little concurrence between laboratory studies, field studies and research groups. In the current study, changes in concentration of seven out of eleven investigated volatile DBPs were observed in experiments using medium pressure UV treatment, with and without chlorine and after post-UV chlorination. Results showed that post-UV chlorine consumption increased, dose-dependently, with UV treatment dose. A clear absence of trihalomethane formation by UV and UV with chlorine was observed, while small yet statistically significant increases in dichloroacetonitrile and dichloropropanone concentrations were detected. Results indicate that post-UV chlorination clearly induced secondary formation of several DBPs. However, the formation of total trihalomethanes was no greater than what could be replicated by performing the DBP formation assay with higher chlorine concentrations to simulate extended chlorination. Post-UV chlorination of water from a swimming pool that continuously uses UV treatment to control combined chlorine could not induce secondary formation for most DBPs. Concurrence for induction of trihalomethanes was identified between post-UV chlorination treatments and simulated extended chlorination time treatment. Trihalomethanes could not be induced by UV treatment of water from a continuously UV treated pool. This indicates that literature reports of experimentally induced trihalomethane formation by UV may be a result of kinetic increase in formation by UV. However, this does not imply that higher trihalomethane concentrations would occur in pools that apply continuous UV treatment. The bromine fraction of halogens in formed trihalomethanes increased with UV dose. This indicates that UV removes bromine atoms from larger molecules that participate in trihalomethane production during post-UV chlorination. Additionally, no significant

  6. Secondary formation of disinfection by-products by UV treatment of swimming pool water

    Formation of disinfection by-products (DBPs) during experimental UV treatment of pool water has previously been reported with little concurrence between laboratory studies, field studies and research groups. In the current study, changes in concentration of seven out of eleven investigated volatile DBPs were observed in experiments using medium pressure UV treatment, with and without chlorine and after post-UV chlorination. Results showed that post-UV chlorine consumption increased, dose-dependently, with UV treatment dose. A clear absence of trihalomethane formation by UV and UV with chlorine was observed, while small yet statistically significant increases in dichloroacetonitrile and dichloropropanone concentrations were detected. Results indicate that post-UV chlorination clearly induced secondary formation of several DBPs. However, the formation of total trihalomethanes was no greater than what could be replicated by performing the DBP formation assay with higher chlorine concentrations to simulate extended chlorination. Post-UV chlorination of water from a swimming pool that continuously uses UV treatment to control combined chlorine could not induce secondary formation for most DBPs. Concurrence for induction of trihalomethanes was identified between post-UV chlorination treatments and simulated extended chlorination time treatment. Trihalomethanes could not be induced by UV treatment of water from a continuously UV treated pool. This indicates that literature reports of experimentally induced trihalomethane formation by UV may be a result of kinetic increase in formation by UV. However, this does not imply that higher trihalomethane concentrations would occur in pools that apply continuous UV treatment. The bromine fraction of halogens in formed trihalomethanes increased with UV dose. This indicates that UV removes bromine atoms from larger molecules that participate in trihalomethane production during post-UV chlorination. Additionally, no significant

  7. German students in Austria: A psychometric pilot study on developing a modified version of the Sociocultural Adaptation Scale

    Renner, Walter; Salem, Ingrid; Menschik-Bendele, Jutta

    2012-01-01

    In previous studies, the Sociocultural Adaptation Scale (SCAS) has been employed in studying migrants’ and sojourners’ adaptation to geographically and linguistically distant cultures. In the present study, the SCAS has been modified according to the needs of German students of psychology in Austria. In line with social identity theory and previous empirical evidence, despite the two countries’ vicinity, considerable ethnic tension and adaptation problems of Germans in Austria were expected. ...

  8. Sleeping Beauty. Revitalisation of the old indoor swimming pool Heidelberg; Sleeping Beauty. Revitalisierung des alten Hallenbads Heidelberg

    Paul, Jochen

    2010-07-01

    Since its closure before nearly 30 years due to safety aspects, the monument protected indoor swimming pool in Heidelberg (Federal Republic of Germany) dilapidated appreciably. Only after moving away of the local council from its demand of the wet use, an investor could be found.

  9. Reactor TRIGA PUSPATI (RTP) spent fuel pool conceptual design

    Reactor TRIGA PUSPATI (RTP) is the one and only research reactor in Malaysia that has been safely operated and maintained since 1982. In order to enhance technical capabilities and competencies especially in nuclear reactor engineering a feasibility study on RTP power upgrading was proposed to serve future needs for advance nuclear science and technology in the country with the capability of designing and develop reactor system. The need of a Spent Fuel Pool begins with the discharge of spent fuel elements from RTP for temporary storage that includes all activities related to the storage of fuel until it is either sent for reprocessed or sent for final disposal. To support RTP power upgrading there will be major RTP systems replacement such as reactor components and a new temporary storage pool for fuel elements. The spent fuel pool is needed for temporarily store the irradiated fuel elements to accommodate a new reactor core structure. Spent fuel management has always been one of the most important stages in the nuclear fuel cycle and considered among the most common problems to all countries with nuclear reactors. The output of this paper will provide sufficient information to show the Spent Fuel Pool can be design and build with the adequate and reasonable safety assurance to support newly upgraded TRIGA PUSPATI TRIGA Research Reactor. (author)

  10. Swimming training induces liver mitochondrial adaptations to oxidative stress in rats submitted to repeated exhaustive swimming bouts.

    Frederico D Lima

    Full Text Available BACKGROUND AND AIMS: Although acute exhaustive exercise is known to increase liver reactive oxygen species (ROS production and aerobic training has shown to improve the antioxidant status in the liver, little is known about mitochondria adaptations to aerobic training. The main objective of this study was to investigate the effects of the aerobic training on oxidative stress markers and antioxidant defense in liver mitochondria both after training and in response to three repeated exhaustive swimming bouts. METHODS: Wistar rats were divided into training (n = 14 and control (n = 14 groups. Training group performed a 6-week swimming training protocol. Subsets of training (n = 7 and control (n = 7 rats performed 3 repeated exhaustive swimming bouts with 72 h rest in between. Oxidative stress biomarkers, antioxidant activity, and mitochondria functionality were assessed. RESULTS: Trained group showed increased reduced glutathione (GSH content and reduced/oxidized (GSH/GSSG ratio, higher superoxide dismutase (MnSOD activity, and decreased lipid peroxidation in liver mitochondria. Aerobic training protected against exhaustive swimming ROS production herein characterized by decreased oxidative stress markers, higher antioxidant defenses, and increases in methyl-tetrazolium reduction and membrane potential. Trained group also presented higher time to exhaustion compared to control group. CONCLUSIONS: Swimming training induced positive adaptations in liver mitochondria of rats. Increased antioxidant defense after training coped well with exercise-produced ROS and liver mitochondria were less affected by exhaustive exercise. Therefore, liver mitochondria also adapt to exercise-induced ROS and may play an important role in exercise performance.

  11. Prevalence of ocular, respiratory and cutaneous symptoms in indoor swimming pool workers and exposure to disinfection by-products (DBPs).

    Fantuzzi, Guglielmina; Righi, Elena; Predieri, Guerrino; Giacobazzi, Pierluigi; Mastroianni, Katia; Aggazzotti, Gabriella

    2010-04-01

    The objective of this cross-sectional study was to investigate the prevalence of self-reported respiratory, ocular and cutaneous symptoms in subjects working at indoor swimming pools and to assess the relationship between frequency of declared symptoms and occupational exposure to disinfection by-products (DBPs). Twenty indoor swimming pools in the Emilia Romagna region of Italy were included in the study. Information about the health status of 133 employees was collected using a self-administered questionnaire. Subjects working at swimming pools claimed to frequently experience the following symptoms: cold (65.4%), sneezing (52.6%), red eyes (48.9%) and itchy eyes (44.4%). Only 7.5% claimed to suffer from asthma. Red eyes, runny nose, voice loss and cold symptoms were declared more frequently by pool attendants (lifeguards and trainers) when compared with employees working in other areas of the facility (office, cafe, etc.). Pool attendants experienced generally more verrucas, mycosis, eczema and rash than others workers; however, only the difference in the frequency of self-declared mycosis was statistically significant (p = 0.010). Exposure to DBPs was evaluated using both environmental and biological monitoring. Trihalomethanes (THMs), the main DBPs, were evaluated in alveolar air samples collected from subjects. Swimming pool workers experienced different THM exposure levels: lifeguards and trainers showed the highest mean values of THMs in alveolar air samples (28.5 +/- 20.2 microg/m(3)), while subjects working in cafe areas (17.6 +/- 12.1 microg/m(3)), offices (14.4 +/- 12.0 microg/m(3)) and engine rooms (13.6 +/- 4.4 microg/m(3)) showed lower exposure levels. Employees with THM alveolar air values higher than 21 microg/m(3) (median value) experienced higher risks for red eyes (OR 6.2; 95% CI 2.6-14.9), itchy eyes (OR 3.5; 95% CI 1.5-8.0), dyspnea/asthma (OR 5.1; 95% CI 1.0-27.2) and blocked nose (OR 2.2; 95% CI 1.0-4.7) than subjects with less exposure

  12. Prevalence of Ocular, Respiratory and Cutaneous Symptoms in Indoor Swimming Pool Workers and Exposure to Disinfection By-Products (DBPs

    Guglielmina Fantuzzi

    2010-03-01

    Full Text Available The objective of this cross-sectional study was to investigate the prevalence of self-reported respiratory, ocular and cutaneous symptoms in subjects working at indoor swimming pools and to assess the relationship between frequency of declared symptoms and occupational exposure to disinfection by-products (DBPs. Twenty indoor swimming pools in the Emilia Romagna region of Italy were included in the study. Information about the health status of 133 employees was collected using a self-administered questionnaire. Subjects working at swimming pools claimed to frequently experience the following symptoms: cold (65.4%, sneezing (52.6%, red eyes (48.9% and itchy eyes (44.4%. Only 7.5% claimed to suffer from asthma. Red eyes, runny nose, voice loss and cold symptoms were declared more frequently by pool attendants (lifeguards and trainers when compared with employees working in other areas of the facility (office, cafe, etc.. Pool attendants experienced generally more verrucas, mycosis, eczema and rash than others workers; however, only the difference in the frequency of self-declared mycosis was statistically significant (p = 0.010. Exposure to DBPs was evaluated using both environmental and biological monitoring. Trihalomethanes (THMs, the main DBPs, were evaluated in alveolar air samples collected from subjects. Swimming pool workers experienced different THM exposure levels: lifeguards and trainers showed the highest mean values of THMs in alveolar air samples (28.5 ± 20.2 µg/m3, while subjects working in cafe areas (17.6 ± 12.1 µg/m3, offices (14.4 ± 12.0 µg/m3 and engine rooms (13.6 ± 4.4 µg/m3 showed lower exposure levels. Employees with THM alveolar air values higher than 21 µg/m3 (median value experienced higher risks for red eyes (OR 6.2; 95% CI 2.6–14.9, itchy eyes (OR 3.5; 95% CI 1.5–8.0, dyspnea/asthma (OR 5.1; 95% CI 1.0–27.2 and blocked nose (OR 2.2; 95% CI 1.0–4.7 than subjects with less exposure. This study confirms

  13. OPPORTUNITIES FOR PSYCHO-MOTOR SKILLS DEVELOPMENT IN CHILDREN WITH DOWN SYNDROME - ADAPTED SWIMMING -

    Chera-Ferrario B.

    2012-01-01

    Sport activities have a beneficial effect on the mind and body of any type of person. The benefits of sport are even more evident in children with Down Syndrome, who exhibit a general delay in neuro-motor structures. Our aim was to develop the psycho-motor skills in children with Down Syndrome through adapted swimming exercises. We believe that our involvement in adapted swimming for children with Down Syndrome may help develop certain aspects of psycho-motor abilities. The swimming took p...

  14. Diarrhea and Swimming

    ... Pool What to Do if You Have Diarrhea Diarrhea and Swimming Diarrhea and swimming don’t mix! ... small amount of pool water to become infected. Diarrhea and Spreading Illness at the Pool Infectious diarrhea ...

  15. Health-Related Behaviors in Swimming Pool Users: Influence of Knowledge of Regulations and Awareness of Health Risks

    Gallè, Francesca; Dallolio, Laura; Marotta, Manfredo; Raggi, Alessandra; Di Onofrio, Valeria; Liguori, Giorgio; Toni, Francesco; Leoni, Erica

    2016-01-01

    Background: Swimming pool attendance exposes users to infection and chemical risks that could be largely reduced with the adoption of healthy behaviors. This study aims to investigate if the knowledge of swimming pool regulations and awareness of health risks can be associated with users’ health-related behaviors. Methods: A cross-sectional study was conducted using self-administered questionnaires to collect data from two different target groups of swimming users: 184 adults and 184 children/adolescents. The association between specific variables and patterns of behaviors and knowledge was assessed through multivariate logistic regression models. Results: Although more than 80% of both groups declared they knew the regulations, compliance with healthy behaviors was often unsatisfactory, especially in adolescents and youth. In the children/adolescents group, healthy behaviors significantly increased with the frequency of attendance per week. In both groups, compliance increased with educational level (of parents for children/adolescents), while no positive association was observed between viewing the regulations and adopting appropriate behaviors. In the adult group, a higher knowledge/awareness of health risks was related to decreased odds of at least one unhealthy behavior. Conclusions: Guaranteeing the public display of regulations in swimming facilities is not sufficient to promote and change health-related behaviors. Much more attention should be given to educational interventions aimed to increase knowledge of health risks and the awareness that bathers are directly responsible for their own well-being. PMID:27213417

  16. Analytical simulation of boiling water reactor pressure suppression pool swell

    In a loss-of-coolant accident, the pressure suppression pool of a boiling water reactor swells as a steam/air mixture is expelled from the drywell into the pool and large gas bubbles are formed beneath the surface. Many tests have been performed to quantify pool swell loads, but analytical methods have been limited in their ability to provide accurate loading estimates. With advancement of numerical methods, it is now feasible to numerically simulate the pool swell process. A finite difference solution algorithm is used to solve the transient imcompressible equations for the liquid flow field. Boundary conditions at the fluid-gas interface are determined using a simplified gas flow model. The program is used to simulate several pool swell tests: comparison of the simulation with test data shows good agreement

  17. Analytical simulation of boiling water reactor pressure suppression pool swell

    Widener, S.K.

    1986-01-01

    In a loss-of-coolant accident, the pressure suppression pool of a boiling water reactor swells as a steam/air mixture is expelled from the drywell into the pool and large gas bubbles are formed beneath the surface. Many tests have been performed to quantify pool swell loads, but analytical methods have been limited in their ability to provide accurate loading estimates. With advancement of numerical methods, it is now feasible to numerically simulate the pool swell process. A finite difference solution algorithm is used to solve the transient imcompressible equations for the liquid flow field. Boundary conditions at the fluid-gas interface are determined using a simplified gas flow model. The program is used to simulate several pool swell tests: comparison of the simulation with test data shows good agreement.

  18. Airborne trichloramine (NCl(3)) levels and self-reported health symptoms in indoor swimming pool workers: dose-response relationships.

    Fantuzzi, Guglielmina; Righi, Elena; Predieri, Guerrino; Giacobazzi, Pierluigi; Petra, Berchotd; Aggazzotti, Gabriella

    2013-01-01

    The hypothesis that attendance at indoor chlorinated swimming pool is a risk factor for irritative ocular and respiratory symptoms and bronchial asthma is well known in literature, although epidemiological evidence is still inconclusive. The aim of this study was to evaluate the association between airborne trichloramine (NCl(3)) levels and irritative symptoms in swimming pool employees in order to obtain detailed data regarding dose-response relationships and to identify the airborne NCl(3) exposure level, if any, without health effects. A total of 20 indoor swimming pools in the Emilia Romagna region of Italy were included in the study. Information about the health status of 128 employees was collected using a self-administered questionnaire. Exposure to airborne NCl(3) was evaluated in indoor swimming pools by a modified DPD/KI method. The results of the study evidenced a mean value of airborne NCl(3) of 0.65±0.20 mg/m(3) (ranging from 0.20 to 1.02 mg/m(3)). Both ocular and upper respiratory symptoms, in particular red eyes, runny nose, voice loss and cold symptoms, were declared more frequently by lifeguards and trainers when compared with employees working in other areas of the facility (office, cafe, and so on). Pool attendants exposed to airborne NCl(3) levels of >0.5 mg/m(3) experienced higher risks for runny nose (OR: 2.91; 95% CI: 1.22-6.93) red eyes (OR: 3.16; 95% CI: 1.46-6.82), voice loss (OR: 3.56; 95% CI: 1.60-7.95) and itchy eyes (OR: 2.23; 95% CI: 1.04-4.78) than other employees. Moreover, red eyes, itchy eyes, runny nose and voice loss are related to airborne NCl(3) levels, with strong dose-response relationships. In conclusion, this study shows that lifeguards and trainers experience ocular and respiratory irritative symptoms more frequently than employees not exposed. Irritative symptoms become significant starting from airborne NCl(3) levels of >0.5 mg/m(3), confirming that the WHO-recommended value can be considered protective in

  19. Convective cooling in a pool-type research reactor

    Sipaun, Susan; Usman, Shoaib

    2016-01-01

    A reactor produces heat arising from fission reactions in the nuclear core. In the Missouri University of Science and Technology research reactor (MSTR), this heat is removed by natural convection where the coolant/moderator is demineralised water. Heat energy is transferred from the core into the coolant, and the heated water eventually evaporates from the open pool surface. A secondary cooling system was installed to actively remove excess heat arising from prolonged reactor operations. The nuclear core consists of uranium silicide aluminium dispersion fuel (U3Si2Al) in the form of rectangular plates. Gaps between the plates allow coolant to pass through and carry away heat. A study was carried out to map out heat flow as well as to predict the system's performance via STAR-CCM+ simulation. The core was approximated as porous media with porosity of 0.7027. The reactor is rated 200kW and total heat density is approximately 1.07+E7 Wm-3. An MSTR model consisting of 20% of MSTR's nuclear core in a third of the reactor pool was developed. At 35% pump capacity, the simulation results for the MSTR model showed that water is drawn out of the pool at a rate 1.28 kg s-1 from the 4" pipe, and predicted pool surface temperature not exceeding 30°C.

  20. Convective cooling in a pool-type research reactor

    Sipaun, Susan, E-mail: susan@nm.gov.my [Malaysian Nuclear Agency, Industrial Technology Division, Blok 29T, Bangi 43200, Selangor (Malaysia); Usman, Shoaib, E-mail: usmans@mst.edu [Missouri University of Science and Technology, Nuclear Engineering, 222 Fulton Hall 301 W.14th St., Rolla 64509 MO (United States)

    2016-01-22

    A reactor produces heat arising from fission reactions in the nuclear core. In the Missouri University of Science and Technology research reactor (MSTR), this heat is removed by natural convection where the coolant/moderator is demineralised water. Heat energy is transferred from the core into the coolant, and the heated water eventually evaporates from the open pool surface. A secondary cooling system was installed to actively remove excess heat arising from prolonged reactor operations. The nuclear core consists of uranium silicide aluminium dispersion fuel (U{sub 3}Si{sub 2}Al) in the form of rectangular plates. Gaps between the plates allow coolant to pass through and carry away heat. A study was carried out to map out heat flow as well as to predict the system’s performance via STAR-CCM+ simulation. The core was approximated as porous media with porosity of 0.7027. The reactor is rated 200kW and total heat density is approximately 1.07+E7 Wm{sup −3}. An MSTR model consisting of 20% of MSTR’s nuclear core in a third of the reactor pool was developed. At 35% pump capacity, the simulation results for the MSTR model showed that water is drawn out of the pool at a rate 1.28 kg s{sup −1} from the 4” pipe, and predicted pool surface temperature not exceeding 30°C.

  1. Convective cooling in a pool-type research reactor

    A reactor produces heat arising from fission reactions in the nuclear core. In the Missouri University of Science and Technology research reactor (MSTR), this heat is removed by natural convection where the coolant/moderator is demineralised water. Heat energy is transferred from the core into the coolant, and the heated water eventually evaporates from the open pool surface. A secondary cooling system was installed to actively remove excess heat arising from prolonged reactor operations. The nuclear core consists of uranium silicide aluminium dispersion fuel (U3Si2Al) in the form of rectangular plates. Gaps between the plates allow coolant to pass through and carry away heat. A study was carried out to map out heat flow as well as to predict the system’s performance via STAR-CCM+ simulation. The core was approximated as porous media with porosity of 0.7027. The reactor is rated 200kW and total heat density is approximately 1.07+E7 Wm−3. An MSTR model consisting of 20% of MSTR’s nuclear core in a third of the reactor pool was developed. At 35% pump capacity, the simulation results for the MSTR model showed that water is drawn out of the pool at a rate 1.28 kg s−1 from the 4” pipe, and predicted pool surface temperature not exceeding 30°C

  2. Plenum separator system for pool-type nuclear reactors

    A pool-type liquid-metal-heat-transfer nuclear reactor is described which consists of: a vertically disposed generally cylindrical reactor vessel having a closed bottom portion, and a closure head atop the reactor vessel and closing the reactor vessel; the reactor vessel enclosing the major components of the nuclear reactor which include a reactor core supported at a centrally disposed lower portion of the reactor vessel; a bottom-supported gas-plenum-forming hollow cylindrical member closed at its upper end, the hollow cylindrical member sealed to and supported by the reactor vessel; a hollow cylindrically conformed neutron shield member spaced from and radially surrounding the reactor core; separate liquid-metal plena confining liquid metal during normal reactor operation and comprising a hot upper plenum, a cold lower plenum and intermediate temperature plena; the liquid metal intakes of the liquid metal pumps positioned in the cold lower plenum with the cooler liquid metal therein being pumped upwardly through the reactor core to be heated and exit therefrom in a turbulent fashion; and the liquid metal intakes of the heat exchangers positioned within the hot upper plenum and the liquid metal discharges of the heat exchangers positioned within the cold lower plenum to discharge cooled liquid metal into the cold lower plenum

  3. Design guide for Category III reactors: pool type reactors

    The Department of Energy (DOE) in the ERDA Manual requires that all DOE-owned reactors be sited, designed, constructed, modified, operated, maintained, and decommissioned in a manner that gives adequate consideration to health and safety factors. Specific guidance pertinent to the safety of DOE-owned reactors is found in Chapter 0540 of the ERDA Manual. The purpose of this Design Guide is to provide additional guidance to aid the DOE facility contractor in meeting the requirement that the siting, design, construction, modification, operation, maintenance, and decommissioning of DOE-owned reactors be in accordance with generally uniform standards, guides, and codes which are comparable to those applied to similar reactors licensed by the Nuclear Regulatory Commission (NRC). This Design Guide deals principally with the design and functional requirement of Category III reactor structures, components, and systems

  4. Observation of fallout deposition in an outdoor swimming pool 50 km away from the Fukushima Daiichi nuclear power plant

    After the accident at the Fukushima Daiichi nuclear power plant (NPP), outdoor school swimming pools at Fukushima were decontaminated to curb the redistribution of radioactivity into downstream farmlands. In the process, the radioactivity concentrations of the pool water and sediment substances (residue) were measured to estimate the deposition density of the fallout. At a pool situated 50 km away from the NPP, the average concentrations of radiocesium (134+137Cs) for the water and residue were quantified as 170 Bq L−1 and 3.6 × 105 Bq kg−1, respectively. Taking account of the radioactivity concentrations and of the water balance in and around the pool, the deposition density of radiocesium, as of August 2011, was precisely determined to be 0.32 ± 0.03 MBq m−2 (k = 1). The density corroborated the previous results obtained by other methods, i.e., airborne surveys, in-situ Ge surveys and soil samplings at neighboring locations. Other than radiocesium, the only gamma-emitting nuclide detected was 110mAg, with a concentration of 560 Bq kg−1 in the residue. The radioactivity concentrations of 89Sr, 90Sr, 238Pu and 239+240Pu in the water were all less than the minimum detectable activities – 2, 0.1, 0.002 and 0.002 Bq L−1, respectively. - Highlights: • Deposition density of radiocesium was estimated at a swimming pool in Fukushima. • The density was determined with a small standard uncertainty of approximately 10%. • Water balance was simulated for estimating radioactivity budget in the pool. • Detected gamma-emitting nuclide was 110mAg other than radiocesium. • Radiocesium was much dominant compared with 89Sr, 90Sr, 110mAg, 238Pu and 239+240Pu

  5. A pilot-scale study of Cryptosporidium-sized microsphere removals from swimming pools via sand filtration.

    Lu, Ping; Amburgey, James E

    2016-02-01

    Cryptosporidium species are the most common cause of gastrointestinal illness in treated recreational water venues. In order to protect public health during swimming, Cryptosporidium-sized microsphere removals by high-rate sand filtration with six coagulants were evaluated with a 5.5 m(3) pilot-scale swimming pool. A sand filter without coagulation removed 20-63% of Cryptosporidium-sized microspheres. Cryptosporidium-sized microsphere removals exceeded 98% by sand filtration with five of the six tested coagulants. Continuously feeding coagulants A, B, and F (i.e., organic polymers) led to coagulant accumulation in the system and decreased removals over time (chitosan-based product that removed fewer microspheres compared with other products, filter efficiency. PMID:26837835

  6. Dynamic simulation and thermo-economic analysis of a PhotoVoltaic/Thermal collector heating system for an indoor–outdoor swimming pool

    Highlights: • A PV/T heating system for indoor–outdoor swimming pools is proposed. • A comparison among some thermal pool models available in literature is carried out. • Dynamic simulations of the thermal behavior of the swimming-pools are performed. • PV/T thermal energy is used to heat the swimming pool and for DHW production. • Energy and economic parametric analyses of the proposed system are presented. - Abstract: This paper presents an analysis of an innovative renewable energy plant serving an existing indoor/outdoor swimming pool located in Naples. The proposed solar hybrid system is designed in order to balance the remarkable energy demand of the swimming pool facility and to ensure suitable comfort conditions for swimmers. With the aim to accomplish such goals, the dynamic thermal behavior of the swimming pool was analyzed as a function of the thermo-hygrometric conditions of the indoor space and on the meteorological conditions of the pool site. In order to properly design and size the proposed renewable energy system, different thermal pool loss formulations for the calculation of the swimming pool thermal balance, in indoor and outdoor regimes, are adopted. The solar hybrid system consists of a water cooled photovoltaic/thermal collectors plant (PV/T), designed to meet a part of the facility demands of electricity and heat. Electricity is completely utilized by the facility, while the produced thermal energy is primarily used to meet the pool thermal demand and secondarily for sanitary hot water scopes. In order to carry out dynamic simulations and sensitivity analyses, the system performance is designed and dynamically simulated in TRNSYS environment. The developed simulation model enables the calculation of both the indoor and outdoor swimming pool thermal losses and the overall energy and economic system performance. Such results are obtained as a function of the thermo-hygrometric conditions of the environment, of the occupants and the

  7. UV filters interaction in the chlorinated swimming pool, a new challenge for urbanization, a need for community scale investigations.

    Sharifan, Hamidreza; Klein, David; Morse, Audra N

    2016-07-01

    Sunscreen products and some personal care products contain the Ultraviolet (UV) chemical filters, which are entering the surface water. Public concerns about secondary effects of these compounds are growing because of the contamination of the aquatic environment that may reach to potentially toxic concentration levels. This article highlights the reaction of certain UV filters with hypochlorite disinfectant in the presence of sunlight. Due to urbanization and industrialization, use of outdoor plastic swimming pools is increasing. The relatively smaller volume of these pools compared to larger pools may increase the concentration of the UV filters in the pool and their potential interactions with materials of human origin (urine, sweat, cosmetics, skin cells, and hair) to the levels of toxicity concerns for children through the creation of disinfection by products (DBP). Based on our analysis, the minimum concentration levels of 2.85, 1.9, 1.78 and 0.95g/L, respectively, for EHMC, OC, 4-MBC and BP3 UV filters in children pools are predicted. Therefore, this article calls for an urgent investigation of potential toxic effects of the UV filters, the creation of DBPs and their subsequent impacts on human health. PMID:27088731

  8. ‘Right now, Sophie *swims in the pool?!’: Brain potentials of grammatical aspect processing

    Monique eFlecken

    2015-11-01

    Full Text Available We investigated whether brain potentials of grammatical aspect processing resemble semantic or morpho-syntactic processing, or whether they instead are characterized by an entirely distinct pattern in the same individuals. We studied aspect from the perspective of agreement between the temporal information in the context (temporal adverbials, e.g., Right now and a morpho-syntactic marker of grammatical aspect (e.g., progressive is swimming. Participants read questions providing a temporal context that was progressive (What is Sophie doing in the pool right now? or habitual (What does Sophie do in the pool every Monday?. Following a lead-in sentence context such as Right now, Sophie…, we measured ERPs time-locked to verb phrases in four different conditions, e.g., (a is swimming (control; (b *is cooking (semantic violation; (c *are swimming (morpho-syntactic violation; or (d?swims (aspect mismatch; …in the pool. The collected ERPs show typical N400 and P600 effects for semantics and morpho-syntax, while aspect processing elicited an Early Negativity (250-350 ms. The aspect-related Negativity was short-lived and had a central scalp distribution with an anterior onset. This differentiates it not only from the semantic N400 effect, but also from the typical (LAN (Left Anterior Negativity, that is frequently reported for various types of agreement processing. Moreover, aspect processing was not accompanied by a clear P600 modulation.We argue that the specific context for each item in this experiment provided a trigger for agreement checking with temporal information encoded on the verb, i.e., morphological aspect marking. The aspect-related Negativity obtained for aspect agreement mismatches reflects a violated expectation concerning verbal inflection (in the example above, the expected verb phrase was Sophie is X-ing rather than Sophie X-s in condition d. The absence of an additional P600 for aspect processing suggests that the mismatch did not

  9. Physiological Adaptations to Training in Competitive Swimming: A Systematic Review

    Costa, Mário J.; Balasekaran, Govindasamy; Vilas-Boas, J. Paulo; Barbosa, Tiago M.

    2015-01-01

    The purpose of this systematic review was to summarize longitudinal studies on swimming physiology and get implications for daily practice. A computerized search of databases according to the PRISMA statement was employed. Studies were screened for eligibility on inclusion criteria: (i) present two testing points; (ii) on swimming physiology; (iii) using adult elite swimmers; (iv) no case-studies or with small sample sizes. Two independent reviewers used a checklist to assess the methodological quality of the studies. Thirty-four studies selected for analysis were gathered into five main categories: blood composition (n=7), endocrine secretion (n=11), muscle biochemistry (n=7), cardiovascular response (n=8) and the energetic profile (n=14). The mean quality index was 10.58 ± 2.19 points demonstrating an almost perfect agreement between reviewers (K = 0.93). It can be concluded that the mixed findings in the literature are due to the diversity of the experimental designs. Micro variables obtained at the cellular or molecular level are sensitive measures and demonstrate overtraining signs and health symptoms. The improvement of macro variables (i.e. main physiological systems) is limited and may depend on the athletes’ training background and experience. PMID:26839618

  10. Radiological consequences of a postulated cooling channel blockage incident at a pool-type research reactor

    An assessment of the radiological consequences of a postulated coolant flow blockage incident at the Hoger Onderwijs Reactor (HOR) is being presented. The HOR is a swimming-pool type research reactor with a maximum licensed power of 3 MW. Assuming a sudden blockage of cooling channels in the high power density region of the core, the source term for the release of radioactivity into the environment was calculated. The magnitude of this source term is required by actions of the HOR protection system as well as by physical processes acting on the fission products. Hence, almost 99% of the calculated release from the containment consists of noble gases; most of the aerosol-type activity set free in the environment results from the decay of these noble gases. The deposit of long-living radionuclides outside the reactor building is very low. Radio-iodine will be the main contributor to the environmental radiation dose, ingestion of contaminated food being the critical pathway. Despite the conservativeness of most assumptions used, the calculated thyroid dose for critical individuals at all distances from the site boundary remains well below the emergency reference levels recommended by national and international organizations and the national dose limit for members of the public

  11. Challenges and lessons-learned during the reactor pool repair at the Penn State Breazeale Reactor

    On October 10, 2007, operators of the Penn State Breazeale Reactor (PSBR) observed the reactor pool level had decreased more than expected over the weekend. Upon further investigation, the staff confirmed that a small leak of 10 gallons had developed in the 52 year old unlined pool. The staff immediately informed the appropriate regulatory authorities and set about finding a solution. Over the next six weeks, the reactor staff worked with University personnel, contractors and regulators to fix the leak and return the facility to normal operation. The Penn State reactor was the first university research reactor licensed by the Atomic Energy Commission. The facility has had several minor pool leaks since its construction in 1955, with the latest occurring in 1976. Each time, the leak was located and repaired with concrete and an epoxy coating. The 2007 leak repair was more extensive involving three-step process that required hydro-lazing the pool wall, removing old sealant, and covering the areas with an epoxy concrete. After these processes the entire pool wall surface was sealed with a polyurea coating. The response from the State of Pennsylvania and US-NRC regulatory authorities was much more involved than earlier leak events. Although public risk was never an issue, the US-NRC immediately dispatched inspectors to the facility so that senior officials could be knowledgeable and responsive to the public's information needs. Additionally, the University set up a team to provide the public and news organizations with ongoing status of the investigation and repair activities. This team allowed the reactor staff to remain focused on the technical aspects of the repair and interface with the regulators. The PSBR pool leak detection and repair will be discussed. Also, PSBR administration and staff, other PSBR functions, coordination with US-NRC and the state of Pennsylvania officials will be presented and experiences gained from this event will be shared with the other

  12. Stabilization of reactor fuel storage pool-TTP

    The proposed work includes evaluating standard and improved technologies an designing an integrated demonstration system to clean the water and sludge the fuel storage pools. The water released would meet drinking water standards and tritium standards. The volume of radioactive sludge would be reduced by partial separation of the sludge and radionuclides and eventual solidification of the hazardous and radioactive waste. The scope of the wo includes a survey of needs and applicable technologies, system engineering evaluation, conceptual design, detailed design, fabrication of the integrat demonstration system, and testing of the system. The survey task will locate potential specific customers within the DOE complex, and outside of the DOE complex throughout the United States, that be able to utilize the narrowly focused technology to stabilize/shutdown reactor fuel storage pools, responsible parties will be located and asked respond to a survey about their specific process requirements. Literature searches will be run through technical and scientific databases to locate technologies that may be an improvement over the standard baselined technol for cleanup of radioactively-contaminated pools. Systems engineering will provide decision analysis support for the development, evaluation, design, test functions of the treatment of pool water and sludge

  13. Conceptual design of a pool type molten salt breeder reactor

    The renewed interest in molten salt coolant technology is backed by the 50 years history of molten salt nuclear technology development, mainly in Oak Ridge National Laboratory (ORNL). In Indian context MSBR is found to be one of the options for sustainable nuclear energy generation, especially in the third stage of the nuclear programme. The system can be operated at high temperature which makes high efficiency power conversion and efficient hydrogen generation through thermo-chemical reactions possible. At present development is in progress in BARC on two molten salt reactor concepts, one is pool type and the other is loop type. Here the design of pool type concept with 850MWe power is described. The core is designed to operate in the fast spectrum region so the conversion of 233U breeding is possible from thorium. Preliminary thermal hydraulic analysis is carried out with LiF-ThF4-UF4 as the primary fuel and coolant. The blanket material is also a molten salt, LiF-ThF4. Reactor physics calculations are also carried out for the feasibility studies of the core design of the reactor. FLiNaK is used as the secondary coolant for the calculations. Both forced circulation and natural circulation options are evaluated. (author)

  14. MUSCLE FIBER SPECIFIC ANTIOXIDATIVE SYSTEM ADAPTATION TO SWIM TRAINING IN RATS: INFLUENCE OF INTERMITTENT HYPOXIA

    Olga Gonchar

    2005-01-01

    The aim of the present study was to examine the influence of intermittent hypoxia at rest and in combination with long-term high-intensity swimming exercise on lipid peroxidation and antioxidant defense system adaptation in skeletal muscles differing in fiber type composition. High-intensity chronic exercise was performed as swimming training with load that corresponded to ~ 75 % VO2max (30 min·day-1, 5 days·wk-1, for 4 wk). Intermittent hypoxic training (IHT) consisted of repeated episodes o...

  15. Shielding Calculations for The New Spent Fuel Storage Pool of Etrr1 Reactor

    MCNP code was used to model and simulate the new spent fuel storage pool of Etrr1 research reactor. Shielding calculations for the pool were performed to calculate the radiation dose through different pool layers. Radiation sources for photons and neutrons inside the pool were determined under different conditions. Key parameters that affect the radiation dose outside the pool were studied. Comparison with the designer values was performed, agreement and disagreement were investigated. Radiation safety of the pool has been verified

  16. Microbiological quality of swimming-pool waters in the province of Badajoz (Spain); Calidad microbiologica de las aguas de piscina en la provinca de Badajoz

    Villalba Doblas, A. M.; Ambel Carracedo, M. P.; Cobos Rodriguez, J. G.

    2006-07-01

    The object of the actual work is to evaluate the microbiological quality of swimming pool waters in the province of Badajoz, 79 samples in 33 cities, according to criteria required by the Decreto 54/2002 of the Comunidad Autonoma of Extremadura. the work describes the possible origins of the pollution in the swimming-pool waters and the risks. The parameters analyzed were Termotolerant Coliforms, Faecal streptococci, S. aureus, P. aerogenes, Sulphate reducing bacteria and Salmonella spp. Results show that 62% of these fulfil microbiological quality criteria. the presence of Sulphate reducing bacteria was found in 24% of the samples, and P. aerogenes was detected in 16% of them. (Author) 20 refs.

  17. Adapting the reactors Melusine and Siloe to the needs of basic research on exit beams

    This report shows how CENG swimming pools can be adapted to meet developing needs of basic research on exit beams. The experimental facilities offered are: two radial channels on Siloe and three radial and two tangential channels on Melusine. The use of various channels is outlined and modifications made to the channels described. Improvements involved the socks, protective shielding systems and collimator plugs and at Melusine, the installation of a heavy water tank. Some future trends are outlined

  18. MUSCLE FIBER SPECIFIC ANTIOXIDATIVE SYSTEM ADAPTATION TO SWIM TRAINING IN RATS: INFLUENCE OF INTERMITTENT HYPOXIA

    Olga Gonchar

    2005-06-01

    Full Text Available The aim of the present study was to examine the influence of intermittent hypoxia at rest and in combination with long-term high-intensity swimming exercise on lipid peroxidation and antioxidant defense system adaptation in skeletal muscles differing in fiber type composition. High-intensity chronic exercise was performed as swimming training with load that corresponded to ~ 75 % VO2max (30 min·day-1, 5 days·wk-1, for 4 wk. Intermittent hypoxic training (IHT consisted of repeated episodes of hypoxia (12%O2, 15 min, interrupted by equal periods of recovery (5 sessions/day, for 2 wk. Sessions of IHT were used during the first two weeks and during the last two weeks of chronic exercise. Oxidative (red gastrocnemius and soleus, mix and glycolytic (white gastrocnemius muscles were sampled. Our results indicated that high-intensity swim training in combination with sessions of IHT induced more profound antioxidative adaptations in skeletal muscles than the exercise training only. This adaptation has muscle fiber type specificity and is reflected in significantly elevated superoxide dismutase and catalase activities in highly oxidative muscle only. Training adaptation of GSH system (reduced glutathione content, activities of glutathione reductase, glutathione peroxidase, NADPH-supplying enzyme glucose-6-phosphate dehydrogenase occurred both in slow- and fast-twitch muscles. However, this process was more effective in oxidative muscles. IHT attenuated the increase in TBARS content induced by high-intensity swimming training. The test on exercise tolerance demonstrated a significant elevation of the swimming time to exhaustion after IHT at rest and after IHT in conjunction with high-intensity exercise in comparison with untrained and chronically exercised rats. These results confirmed that sessions of IHT might improve exercise tolerance and increase maximal work capacity

  19. Wastewater treatment in a compact intensified wetland system at the Badboot: a floating swimming pool in Belgium.

    Van Oirschot, D; Wallace, S; Van Deun, R

    2015-09-01

    The Badboot (Dutch for swimming pool boat) is a floating swimming pool located in the city center of Antwerp in Belgium. The overall design consists of a recycled ferry boat that serves as a restaurant and next to that a newly built ship that harbours an Olympic size swimming pool, sun decks, locker rooms with showers, and a party space. A major design goal of the project was to make the ship as environmentally friendly as possible. To avoid discharge of contaminated waste water in the Antwerp docks, the ship includes onsite treatment of wastewater in a compact constructed wetland. The treatment wetland system was designed to treat wastewater from visitor locker rooms, showers, toilets, two bars, and the wastewater from the restaurant kitchen. Due to the limited space on board the ship, only 188 m(2) could be allocated to a wetland treatment system. As a result, part of the design included intensification of the wetland treatment process through the use of Forced Bed Aeration, which injects small quantities of air in a very uniform grid pattern throughout the wetland with a mechanical air compressor. The system was monitored between August 2012 and March 2013 (with additional sampling in the autumn of 2014). Flows and loads to the wetland were highly variable, but removal efficiency was extremely high; 99.5 % for chemical oxygen demand (COD), 88.6 % for total nitrogen and 97.2 % for ammonia. The treatment performance was assessed using a first-order, tanks-in-series model (the P-k-C* model) and found to be roughly equivalent to similar intensified wetlands operating in Germany. However, treatment performance was substantially better than data reported on passive wetlands, likely as a result of intensification. Even with mechanically assisted aeration, the total oxygen delivered to the treatment wetlands was insufficient to support conventional nitrification and denitrification, so it is likely that alternate nitrogen removal pathways, such as anammox, are

  20. Refurbishment of Pakistan research reactor (PARR-1) for stainless steel lining of the reactor pool

    Pakistan Research Reactor-1 (PARR-1) is a pool-type research reactor. Reactor aging has resulted in the increase of water seepage from the concrete walls of the reactor pool. To stop the seepage, it was decided to augment the existing pool walls with an inner lining of stainless steel. This could be achieved only if the pool walls could be accessed unhindered and without excessive radiation doses. For this purpose a partial decommissioning was done by removing all active core components including standard/control fuel elements, reflector elements, beam tubes, thermal shield, core support structure, grid plate and the pool's ceramic tiles, etc. An overall decommissioning program was devised which included procedures specific to each item. This led to the development of a fuel transport cask for transportation, and an interim fuel storage bay for temporary storage of fuel elements (until final disposal). The safety of workers and the environment was ensured by the use of specially designed remote handling tools, appropriate shielding and pre-planned exposure reduction procedures based on the ALARA principle. During the implementation of this program, liquid and solid wastes generated were legally disposed of. It is felt that the experience gained during the refurbishment of PARR-1 to install the stainless steel liner will prove useful and better planning and execution for the future decommissioning of PARR-1, in particular, and for other research reactors like PARR-2 (27 kW MNSR), in general. Furthermore, due to the worldwide activities on decommissioning, especially those communicated through the IAEA CRP on 'Decommissioning Techniques for Research Reactors', the importance of early planning has been well recognized. This has made possible the implementation of some early steps like better record keeping, rehiring of trained manpower, and creation of interim and final waste storage. (author)

  1. International Working Group on Fast Reactors Eight Annual Meeting, Vienna, Austria, 15-18 April 1975. Summary Report. Part II

    The Eighth Annual Meeting of the IAEA International Working Group on Past Reactors was held at the IAEA Headquarters in Vienna, Austria, from 15 to 18 April 1975. The Summary Report (Part I) contains the Minutes of the Meeting. The Summary Report (Part II) contains the papers which review the national programmes in the field of LMPBR’s and other presentations at the Meeting. The Summary Report (Part III) contains the discussions on the review of the national programmes

  2. Comparison of pool/loop configurations in the JAEA fast reactor feasibility study

    JAEA conducted a feasibility study on commercialized fast breeder reactor cycle systems from 1999 to 2006 (FS). In the FS, various fast reactor concepts with various power levels, coolant materials and plant configurations were proposed and competed. In the large-scale sodium cooled reactor region, four nuclear industry vendors proposed each original advanced sodium cooled reactor concept in 1999. One was a loop concept which was named 'JSFR' later and the other three were pool concepts. The first competition among the four concepts showed that the economical competitiveness of JSFR is better than pool concepts. Therefore, in the 2000 study, one pool concept was selected and the selected pool concept was refined to compete with JSFR. In this appendix, the selected FS pool concept is described and the pool/loop comparative study in the FS is briefly summarized. Schematic illustration of the reactor vessel of the FS pool is shown. Relation of reactor vessel diameters and electric output of various sodium-cooled reactor concepts are compared. The comparison shows that the FS pool concept has a smaller reactor vessel than recent conceptual large reactors such as SPX-2, SNR-2, EFR and BN-1600. The material amount comparison shows that the reactor vessel and primary system material amount of the FS pool concept is heavier than that of the FS loop concept (JSFR) by approximately 250ton. Because the reactor vessel diameter comparison of various concepts shows that the FS pool concept is one of the most compact pool configurations, the FS pool/loop competition is thought to provide comparative information between the most economical loop and pool concepts

  3. A comparative survey of non-adaptive pooling designs

    Balding, D.J. [Univ. of London (United Kingdom); Bruno, W.J.; Torney, D.C. [Los Alamos National Lab., NM (United States)] [and others

    1996-12-31

    Pooling (or {open_quotes}group testing{close_quotes}) designs for screening clone libraries for rare {open_quotes}positives{close_quotes} are described and compared. We focus on non-adaptive designs in which, in order both to facilitate automation and to minimize the total number of pools required in multiple screenings, all the pools are specified in advance of the experiments. The designs considered include deterministic designs, such as set-packing designs, the widely-used {open_quotes}row and column{close_quotes} designs and the more general {open_quotes}transversal{close_quotes} designs, as well as random designs such as {open_quotes}random incidence{close_quotes} and {open_quotes}random k-set{close_quotes} designs. A range of possible performance measures is considered, including the expected numbers of unresolved positive and negative clones, and the probability of a one-pass solution. We describe a flexible strategy in which the experimenter chooses a compromise between the random k-set and the set-packing designs. In general, the latter have superior performance while the former are nearly as efficient and are easier to construct. 39 refs., 1 fig., 4 tabs.

  4. Towards Adaptive Governance of Common-Pool Mountainous Agropastoral Systems

    Johann Baumgärtner

    2010-05-01

    Full Text Available The paper deals with analyses and propositions for adaptive governance of an alpine (A and an Ethiopian (B agropastoral system with common-pool pastures. Sustainability can be enhanced by augmenting (i the ecological and social capitals in relation to costs and (ii the resilience or adaptive capacity. In (A, a multifunctional agriculture appears to maintain the ecological capital providing many ecosystem services. In (B, the ecological capital can be increased by reversing the trend towards land degradation. In (A, there are several opportunities for reducing the high costs of the social capital. In (B, the institutions should be revised and rules should restrain competitive behavior. (A and (B exhibit a high degree of transformability. Many drivers appear to be responsible for the cycling of the agropastoral and higher level systems vulnerable to multiple stressors. Measures are proposed to escape from possible rigidity (A and poverty (B traps.

  5. Simulation of power excursions - Osiris reactor

    Following the experimental work accomplished in the U.S.A. on Borax 1 and SPERT 1 and the accident of SL 1, the 'Commissariat a l'Energie Atomique' started a research program about the safety of its own swimming Pool reactors, with regard to power excursions. The first research work led to the design of programmed explosive charges, adapted to the simulation of a power excursion. This report describes the application of these methods to the investigation of Osiris safety. (author)

  6. Research reactors - an overview

    West, C.D.

    1997-03-01

    A broad overview of different types of research and type reactors is provided in this paper. Reactor designs and operating conditions are briefly described for four reactors. The reactor types described include swimming pool reactors, the High Flux Isotope Reactor, the Mark I TRIGA reactor, and the Advanced Neutron Source reactor. Emphasis in the descriptions is placed on safety-related features of the reactors. 7 refs., 7 figs., 2 tabs.

  7. The Recreational Water Cycle: From Source Water to Tap Water to Spa and Swimming Pool Water: Effects of Disinfectants and Precursors and Implications for Exposure and Toxicity

    The current study investigates the effect of different disinfection treatments on the disinfection by-products (DBPs) formed in finished drinking water vs. tap water vs. swimming pool water vs. spa waters. To this end, complete water pathway samples (untreated source waters ->fi...

  8. From Source Water to Tap Water to Spa and Swimming Pool Water: Effects of Disinfectanta and Precursors and Implications for Exposure and Toxicity

    Introduction The current study investigated the effect of different disinfection treatments on the disinfection by-products (DBPs) formed in finished drinking water vs. tap water vs. swimming pool water vs. spa waters. To this end, samples across the complete water pathway (untr...

  9. Soil contamination in Northern Austria as aftermath of the Chernobyl reactor accident

    The soil contamination caused by the accident at Chernobyl was very uneven distributed in Austria. In late autumn 1986 soil samples from northern Austria were analysed in order to get to know the actual contamination in terms of figures. The extreme values for Cs-137 found were 962 and 73630 Bq/m2 respectively. 3 refs., 2 figs. (Author)

  10. The risk of contracting infectious diseases in public swimming pools: a review

    Zsófia Barna

    2012-12-01

    Full Text Available A review of pathogenic microorganisms presenting risk of infection in pool based artificial recreational water venues is extracted from the available scientific literature. The microorganisms are grouped both according to their way of spread and their survival and growth strategies and their characteristics relevant for the pool and spa based recreation are discussed. In order to put the proposed risks on a solid basis, among others a ten year excerpt of the waterborne disease statistics of the Centers for Disease Control and Prevention (CDC is used throughout the article.

  11. Natural and mixed convection in the cylindrical pool of TRIGA reactor

    Henry, R.; Tiselj, I.; Matkovič, M.

    2016-05-01

    Temperature fields within the pool of the JSI TRIGA MARK II nuclear research reactor were measured to collect data for validation of the thermal hydraulics computational model of the reactor tank. In this context temperature of the coolant was measured simultaneously at sixty different positions within the pool during steady state operation and two transients. The obtained data revealed local peculiarities of the cooling water dynamics inside the pool and were used to estimate the coolant bulk velocity above the reactor core. Mixed natural and forced convection in the pool were simulated with a Computational Fluid Dynamics code. A relatively simple CFD model based on Unsteady RANS turbulence model was found to be sufficient for accurate prediction of the temperature fields in the pool during the reactor operation. Our results show that the simple geometry of the TRIGA pool reactor makes it a suitable candidate for a simple natural circulation benchmark in cylindrical geometry.

  12. An Innovative Hybrid Loop-Pool Design for Sodium Cooled Fast Reactor

    The existing sodium cooled fast reactors (SFR) have two types of designs--loop type and pool type. In the loop type design, such as JOYO (Japan) [1] and MONJU (Japan), the primary coolant is circulated through intermediate heat exchangers (IHX) external to the reactor tank. The major advantages of loop design include compactness and easy maintenance. The disadvantage is higher possibility of sodium leakage. In the pool type design such as EBR-II (USA), BN-600M(Russia), Superphenix (France) and European Fast Reactor [2], the reactor core, primary pumps, IHXs and direct reactor auxiliary cooling system (DRACS) heat exchangers (DHX) all are immersed in a pool of sodium coolant within the reactor vessel, making a loss of primary coolant extremely unlikely. However, the pool type design makes primary system large. In the latest ANL's Advanced Burner Test Reactor (ABTR) design [3], the primary system is configured in a pool-type arrangement. The hot sodium at core outlet temperature in hot pool is separated from the cold sodium at core inlet temperature in cold pool by a single integrated structure called Redan. Redan provides the exchange of the hot sodium from hot pool to cold pool through IHXs. The IHXs were chosen as the traditional tube-shell design. This type of IHXs is large in size and hence large reactor vessel is needed

  13. Operational and research activities of Tsing Hua open pool reactor

    Tsing Hua Open Pool Reaction (THOR) is the first nuclear reactor to become operational in Taiwan. It reached its first critical on April 13, 1961. Until now, THOR has been operated successfully for 27 years. The major missions of THOR include radioisotope production, neutron activation analysis, nuclear science and engineering researches, education, and personnel training. The THOR was originally loaded with HEU MTR-type fuels. A gradual fuel replacing program using LEU TRIGA fuel to replace MTR started in 1977. By 1987, THOR was loaded with all TRIGA fuels. This paper gives a brief history of THOR, its current status, the core conversion work, some selected research topics, and its improvement plan. (author)

  14. An insight of disinfection by-product (DBP) formation by alternative disinfectants for swimming pool disinfection under tropical conditions.

    Yang, Linyan; Schmalz, Christina; Zhou, Jin; Zwiener, Christian; Chang, Victor W-C; Ge, Liya; Wan, Man Pun

    2016-09-15

    Sodium hypochlorite (NaClO) is the most commonly used disinfectant in pool treatment system. Outdoor pools usually suffer from the strong sunlight irradiation which degrades the free chlorine rapidly. In addition, more pools start to adopt the recirculation of swimming pool water, which intensifies the disinfection by-product (DBP) accumulation issue. Given these potential drawbacks of using NaClO in the tropical environment, two alternative organic-based disinfectants, trichloroisocyanuric acid (TCCA, C3Cl3N3O3) and bromochlorodimethylhydantoin (BCDMH, C5H6BrClN2O2), were investigated and compared to NaClO in terms of their self-degradation and the formation of DBPs, including trihalomethanes (THMs) and haloacetic acids (HAAs), under simulated tropical climate conditions. The result reveals that halogen stabilizer, TCCA, had the advantages of slower free chlorine degradation and lower DBP concentration compared to NaClO, which makes it a good alternative disinfectant. BCDMH was not recommended mainly due to the highly reactive disinfecting ingredient, hypobromous acid (HBrO), which fails to sustain the continuous disinfection requirement. Total disinfectant dosage was the main factor that affects residual chlorine/bromine and THM/HAA formation regardless of different disinfectant dosing methods, e.g. shock dosing (one-time spiking) in the beginning, and continuous dosing during the whole experimental period. Two-stage second-order-kinetic-based models demonstrate a good correlation between the measured and predicted data for chlorine decay (R(2) ≥ 0.95), THM (R(2) ≥ 0.99) and HAA (R(2) ≥ 0.83) formation. Higher temperature was found to enhance the DBP formation due to the temperature dependence of reaction rates. Thus, temperature control of pools, especially for those preferring higher temperatures (e.g. hydrotherapy and spa), should take both bather comfort and DBP formation potential into consideration. It is also observed that chlorine competition

  15. System for reducing heat losses from indoor swimming pools by use of automatic covers. Final report, October 1, 1993--September 30, 1995

    NONE

    1996-01-01

    This final report is an account of the principal activities of Lof Energy Systems, Inc. in a two-year project funded by the Energy Related Inventions Program (ERIP) of the U.S. Department of Energy. The primary objective has been the development of a fully practical and economical system for saving energy in indoor swimming pools by use of motorized covers. The goal is wide-spread use of a fully developed product, in institutional swimming pools. Four major tasks, depicted in the accompanying Performance Schedule, have been completed, and one other has been initiated and its completion committed. Principal accomplishments have been the selection and improvement of cover materials and designs, lengthening and strengthening of reels and improvements in motorized components and their control, design and installation of pool covers in full scale demonstration and evaluation of fully developed commercial system, preparation and dissemination of manuals and reports, finalization of arrangements for Underwriters Laboratory certification of products, and final report preparation and submission. Of greatest significance has been the successful demonstration of the fully developed system and the verification and reporting by an energy consultant of the large savings resulting from pool cover use. Probably the best evidence of success of the DOE-ERIP project in advancing this invention to a commercial stage is its acceptance for sale by the Lincoln Equipment Company, a national distributor of swimming pool supplies and equipment. A copy of the relevant page in the Lincoln catalog is included in this report as Annex A. Representatives of that company now offer Tof motorized pool cover systems to their pool owner customers. In addition to the plans for securing UL certification the company expects to continue making design improvements that can increase system reliability, durability, and cost-effectiveness.

  16. Criticality calculations for the spent fuel storage pools for Etrr1 and Etrr2 reactors

    A criticality analysis of two spent fuel storage pools for Etrr1 and Etrr2 research reactors was performed. The multiplication factor for the pools was calculated as a function of relevant lattice physics parameters. Monte Carlo code MNCP-4A code was used in the criticality calculations. The results were compared with those given by CITATION code and results obtained formerly during the design phase of the pools with the MONK 6.3 code. Safety of the pools was confirmed. (author)

  17. Hot Water Layer and Thermal Stratification in an Open-pool type Research Reactor

    Choi, Yong-Seok; Yoon, Hyun-Gi; Choi, Jeongwoon; Kim, Seong-Hoon; Chi, Dae-Young [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    In many open-pool type research reactors, a hot water layer is introduced in the upper part of the pool as a shielding layer to reduce the radiation level on the pool top. By maintaining the hot water layer in a properly higher temperature than the lower part of the pool, a thermally stratified region is developed below the hot water layer and the flows in the lower part of the pool is successfully isolated from the upper part of the pool. This reduces a mass transport from the lower part of the pool to the pool upper part and consequently the radioactivity level on the pool top is also diminished. In this study, the characteristics of the hot water layer and the thermally stratified region in the pool of the KIJANG Research Reactor (KJRR) are investigated. Numerical simulation on a 3D simplified model of the pool of KJRR is conducted using the commercial CFD software ANSYS FLUENT 13.0. The results show initial time evolutions of the temperatures and the flow velocities in the pool toward each quasi steady state. For the shielding analysis in the pool which is required to estimate the radioactivity of the hot water layer, the mixing rate between the hot water layer and the lower part of the pool is important variable as well as the thicknesses of the hot water layer and the stratified region. In further study, the mixing rate will be estimated by post processing the obtained results.

  18. RUTA pool-type reactor for heat supply and the possibility for its application area expansion

    RUTA, a reactor facility with a pool-type reactor, has been designed for heat supply of residential districts. A relatively low potential of the heat generated by the reactor requires a special approach to building up heat supply systems with RUTA facilities. The application of the RUTA facility as a heat source for seawater thermal distillation has been considered. It is possible to use the reactor for neutron therapy. The reactor optimization provides for the improvement of the facility's consumer qualities. (author)

  19. Geothermal heat for Erding. 2. Energy and wellness, geothermal heating station and hot-water indoor swimming pool; Geowaerme fuer Erding 2. Energie und Wellness, Geothermieheizwerk und Thermalbad

    Tenzer, H. (comp.); Bussmann, W.

    1999-07-01

    This 17:20 minute VHS-PAL video film describes the project 'Geothermal heat for Erding 2', i.e. the construction of the geothermal heating station and a modern hot-water indoor swimming pool. [German] Der vorliegende VHS-PAL-Videofilm beschreibt innerhalb von 17:20 Min. Lauflaenge das Projekt 'Geowaerme fuer Erding 2'. Gezeigt werden die Entstehungsphasen dieses Projektes bestehend aus einem Geothermieheizwerk und einem modernen Thermalbad. (AKF)

  20. Human adaptive behavior in common pool resource systems.

    Gunnar Brandt

    Full Text Available Overexploitation of common-pool resources, resulting from uncooperative harvest behavior, is a major problem in many social-ecological systems. Feedbacks between user behavior and resource productivity induce non-linear dynamics in the harvest and the resource stock that complicate the understanding and the prediction of the co-evolutionary system. With an adaptive model constrained by data from a behavioral economic experiment, we show that users' expectations of future pay-offs vary as a result of the previous harvest experience, the time-horizon, and the ability to communicate. In our model, harvest behavior is a trait that adjusts to continuously changing potential returns according to a trade-off between the users' current harvest and the discounted future productivity of the resource. Given a maximum discount factor, which quantifies the users' perception of future pay-offs, the temporal dynamics of harvest behavior and ecological resource can be predicted. Our results reveal a non-linear relation between the previous harvest and current discount rates, which is most sensitive around a reference harvest level. While higher than expected returns resulting from cooperative harvesting in the past increase the importance of future resource productivity and foster sustainability, harvests below the reference level lead to a downward spiral of increasing overexploitation and disappointing returns.

  1. e-Infrastructures Austria

    Sánchez Solís, Barbara

    2014-01-01

    In January 2014, the three-year partner project entitled e-Infrastructures Austria was initiated. The overall objective of this project is the coordinated establishment and development of repository infrastructures for digital resources in research throughout Austria. The initial situation at the 25 participating scientific institutions is very heterogeneous. Through networking and pooling of expertise and resources, a network of knowledge and professional competence is created, which f...

  2. Steps of Healthy Swimming: Protection against Recreational Water Illnesses (RWIs)

    ... Skin, Ear, & Eye Illness Respiratory Illness Neurologic Illness Wound Infections Other Illnesses Swimming Pool Operation & Disinfection Microbial Testing & Disinfection Swimming Pool Chemicals Injuries & Outdoor ...

  3. Twentieth anniversary of German nuclear reactor insurance pool

    When the peaceful utilization of nuclear energy was launched, insurance companies in the countries concerned faced a risk whose magnitude intially was unfathomable and for whose assessment they were not experienced enough, either with respect to the hazard probability or the potential extent of a damage. For this reason a pool, an association on a pro rata base, was organized on a national level by all insurance companies willing to offer coverage. In addition, to further spread the risk, worldwide mutual cooperation was agreed upon among the national pools. The 107 companies which presently make up the German pool cooperate with pools in twenty other countries. (orig.)

  4. ASTEC code adaptability to CANDU type reactors

    ASTEC integral code is dedicated for severe accident (SA) analysis, mainly for PWR type reactors. In the last years, in the FP-6 NoE SARNET project framework, important efforts were focused on the extension of the ASTEC use to other reactors: WWER, RBMK, BWR and CANDU. The use of ASTEC at CANDU type reactors introduces many difficulties especially for the core degradation phenomena. The paper shows some results obtained in exploratory calculation with the modules SOPHAEROS, CPA, IODE, CESAR and DIVA in order to investigate the possibility to use or to adapt the models at CANDU type reactors. An important part of the paper is focused on the models for CANDU core degradation to be implemented in DIVAC module. (authors)

  5. Radiometric analysis of the spent fuel pool water and reactor coolant of ET-RR.1

    This work aims at analysis of radioactivity levels in the water of spent fuel pool and reactor core of the Egyptian 2MW research reactor (ET-RR.1 at Inshas). Gamma spectrometric and laser fluorimetric analysis have been used for carrying out this study. The fission product 137Cs and activation product 60Co are found with very high concentration in the spent fuel storage pool water. Thirteen isotopes; La-140, Cr-51, Ba-140, I-131, Cs-137, Ce-144, Nb-95, Ce-141, Zr-95, Ru-103, Cs-134, Nd-147 and Zn-65 are identified in the reactor core water. However no radiological hazard resulted because the fission products are contained within the shielded reactor pool. The radioactivity released into the reactor coolant water is mainly controlled by the diffusion mechanism. (orig.)

  6. Nuclear policies in Central Europe. Environmental policy and enlargement of the European Union: Austria's policies towards Nuclear Reactors in neighboring countries

    Austria's anti-nuclear policies are rooted in the successful anti-nuclear referendum on the Zwentendorf nuclear power plant (Lower Austria) in 1978 and the great impact of the Chernobyl catastrophe on Austria in 1986. Since about 1990, official Austria has pursued anti-nuclear policies not only at home but also abroad. In particular, reactors in Central and Eastern European Countries (CEEC) are the focal points of Austria's foreign anti-nuclear policies. Strategies include increasing nuclear safety, promoting energy efficiency and sustainable energy sources (such as renewable resources), and extending international legal frameworks to account for nuclear safety. Involvement in domestic energy issues in other countries is not an easy task, and while Austrian policy makers have had some success in increasing awareness of nuclear safety in Europe, they have also made a number of strategic mistakes. Notwithstanding real and substantiated concerns regarding nuclear safety, Austrian policies have lost credibility during recent years. This book explores the history and the development of Austrian anti-nuclear policies, and discusses the political economy of such policies. Particular emphasis is laid on the 2002 referendum against the Temelin reactor in the neighboring Czech Republic. (orig.)

  7. TRIGA-III research reactor pool inspection using an underwater vehicle

    Song, T. K.; Lee, J. R.; Kim, S. H.; Yoon, J. S.; Lee, B. J. [KAERI, Taejon (Korea, Republic of)

    1999-10-01

    For the inspection of radioactivity at the nuclear reactor and spent fuel storage pool, an underwater vehicle system has been developed. This underwater vehicle is navigated freely by five thruster which are controlled by developed control system and has a faculty of radiation detection at the inner wall and special point in pool using the radiation detector which is attached to the bottom of the vehicle. In this paper, the developed underwater vehicle and its components are described in detail. Also, the field test result in TRIGA-III research reactor pool is described.

  8. Thermohydraulic analysis of loss of forced flow accident in a pool type reactor

    This paper shows a calculation model for the fuel and pool water temperatures, and the internal building pressure of a 5 MW pool-type reactor, in the hypothetical event of the forced flow interruption. it is obtained the solution of the thermal energy and the momentum conservation equations in one dimension, which represent the heat conduction and natural convection in the coolant. The reactor building pressure increment due to the partial pool water evaporation is also calculated, using a homogenous model with thermal equilibrium of the phases (liquid water and steam) and the existing air. The heat loss to the building walls is also considered. (Author)

  9. Criticality safety for the new spent fuel storage pool of Etrr-1 reactor

    Etrr-1 is the first egyptian research reactor, it is 36 years old. The decision is taken to equipped the reactor with a new spent fuel storage pool. The facility houses a storage pool besides a handling region. The safety regulations require that the pool when filled with full capacity of fuel assembly FA must be subcritical over a long period during normal and accidental conditions. The present work studies this issues at different pool temperatures. The key parameters affecting pool criticality as lattice pitch and U235 loads are investigated. WIMS and CITATION codes are used in the calculations. The results show good agreement when compared with design calculations which is performed by MCNP code

  10. Quality control of pool water from IEA-R1 reactor

    This paper presents the results of the pool water monitoring program of the IEA-R1 reactor of IPEN/CNEN-SP in normal operation. The considered period was previous to the systems upgrade and modernization for the new reactor operation condition: a power of 5 MW and operation time of 100 hours weekly. (author)

  11. Assembling a computerized adaptive testing item pool as a set of linear tests

    Linden, van der Wim J.; Ariel, Adelaide; Veldkamp, Bernard P.

    2006-01-01

    Test-item writing efforts typically results in item pools with an undesirable correlational structure between the content attributes of the items and their statistical information. If such pools are used in computerized adaptive testing (CAT), the algorithm may be forced to select items with less th

  12. Impact of nuclear power and public acceptance. Licensing of nuclear reactors and public acceptance in Austria

    This paper first reviews the main stages in the development of nuclear activities in Austria and recalls the principal legal and regulatory texts adopted in this field. In this context, the author describes the circumstances which, following announcement of the project for a second nuclear power plant in 1974, gave rise to hostile reactions and led to the organisation by the federal authorities of a wide public information campaign in 1976 and 1977. This resulted in increasing the number of opponents to nuclear energy and raised the question of the long term storage of radioactive waste, for which at present Austrian regulations provide no satisfactory solution. (NEA)

  13. RELAP5 Analysis of the Hybrid Loop-Pool Design for Sodium Cooled Fast Reactors

    Hongbin Zhang; Haihua Zhao; Cliff Davis

    2008-06-01

    An innovative hybrid loop-pool design for sodium cooled fast reactors (SFR-Hybrid) has been recently proposed. This design takes advantage of the inherent safety of a pool design and the compactness of a loop design to improve economics and safety of SFRs. In the hybrid loop-pool design, primary loops are formed by connecting the reactor outlet plenum (hot pool), intermediate heat exchangers (IHX), primary pumps and the reactor inlet plenum with pipes. The primary loops are immersed in the cold pool (buffer pool). Passive safety systems -- modular Pool Reactor Auxiliary Cooling Systems (PRACS) – are added to transfer decay heat from the primary system to the buffer pool during loss of forced circulation (LOFC) transients. The primary systems and the buffer pool are thermally coupled by the PRACS, which is composed of PRACS heat exchangers (PHX), fluidic diodes and connecting pipes. Fluidic diodes are simple, passive devices that provide large flow resistance in one direction and small flow resistance in reverse direction. Direct reactor auxiliary cooling system (DRACS) heat exchangers (DHX) are immersed in the cold pool to transfer decay heat to the environment by natural circulation. To prove the design concepts, especially how the passive safety systems behave during transients such as LOFC with scram, a RELAP5-3D model for the hybrid loop-pool design was developed. The simulations were done for both steady-state and transient conditions. This paper presents the details of RELAP5-3D analysis as well as the calculated thermal response during LOFC with scram. The 250 MW thermal power conventional pool type design of GNEP’s Advanced Burner Test Reactor (ABTR) developed by Argonne National Laboratory was used as the reference reactor core and primary loop design. The reactor inlet temperature is 355 °C and the outlet temperature is 510 °C. The core design is the same as that for ABTR. The steady state buffer pool temperature is the same as the reactor inlet

  14. PASLOCA: two-dimensional code for loss of primary coolant accident analysis in pool type reactors for use in micro computers

    In order to improve the better performance of the MILOCA code, a 2-dimensional code for Loss of Coolant Accident Analysis in pool type research reactor for use in IBM-PC, an adaptation of the code was made from FORTRAN to PASCAL. This paper presents also the heat transfer model calculation from the fuel elements to the air after the draining of the pool water. As an example, the analysis made for the IAEA 2 MW reference reactor is presented. Differences in computing time between the two versions are also shown. (author)

  15. Criticality safety calculations of the Soreq research reactor storage pool

    The IRR-l spent fuel is to be relocated in a storage pool. The present paper describes the actual facility and summarizes the Monte Carlo criticality safety calculations. The fuel elements are to be placed inside cadmium boxes to reduce their reactivity. The fuel element is 7.6 cm by 8.0 cm in the horizontal plane. The cadmium box is effectively 9.7 cm by 9.7 cm, providing significant water between the cadmium and the fuel element. The present calculations show that the spent fuel storage pool is criticality safe even for fresh fuel elements. (author)

  16. Development of thermal-hydraulic system analysis code SSC-K for pool-type liquid metal reactor

    The Supper System Code of KAERI (SSC-K) is a best-estimate system code for analyzing an variety of off-normal or accident of a pool type design. It is developed at KAERI on the basis of SSC-L developed at BNL to analyze pool-type LMR transients. Because of inherent difference between th pool and loop design, the major modefications of SSC-L is required for the safety analysis of KALIMER. The major difference between KALIMER and general loop type LMRs exists in the primary heat transport system. In KALIMER, all of the essential components consisted of the primary heat transport system are located within the reactor vessel. This is contrast to the loop type LMRs, in which all the primary components are connected via piping to form loops attached externally to the reactor vessel. KALIMER has only one cover gas space. This eliminates the need for separate cover gas systems over liquid level in pump tanks and upper plenum. Since the sodium in hot pool is separated from cold pool by insulated barrier in KALIMER, The liquid level in hot pool is different from that in the cold pool mainly due to hydraulic losses and pump suction heads occuring during flow through the circulation pathes. In some accident conditions the liquid in the hot pool is flooded into cold pool and forms the natural circulation flow path. During the loss of heat sink transients, this will provided as a major heat rejection mechanism with the passive decay heat removal system. Since the pipes in the primary system exist only between pump discharge and core inlet plenum and are submerged in cold pool, a pipe rupture accident becomes less severe due to a constant back pressure exerted against the coolant flow from break. The intermediate and steam generator systems of both are generally identical. To adapt SSC-K to KALIMER design, the major modification of SSC-L has been made for the safety analysis of KALIMER. Test runs have been performed for the qualitative verification of the developed models. The

  17. Development of system design and seismic performance evaluation for reactor pool working platform of a research reactor

    Highlights: • Design of reactor pool working platform (RPWP) is newly proposed for an open-tank-in-pool type research reactor. • Main concept of RPWP is to minimize the pool top radiation level. • Framework for seismic performance evaluation of nuclear SSCs in a deterministic and a probabilistic manner is proposed. • Structural integrity, serviceability, and seismic margin of the RPWP are evaluated during and after seismic events. -- Abstract: The reactor pool working platform (RPWP) has been newly designed for an open-tank-in-pool type research reactor, and its seismic response, structural integrity, serviceability, and seismic margin have been evaluated during and after seismic events in this paper. The main important concept of the RPWP is to minimize the pool top radiation level by physically covering the reactor pool of the open-tank-in-pool type research reactor and suppressing the rise of flow induced by the primary cooling system. It is also to provide easy handling of the irradiated objects under the pool water by providing guide tubes and refueling cover to make the radioisotopes irradiated and protect the reactor structure assembly. For this concept, the new three dimensional design model of the RPWP is established for manufacturing, installation and operation, and the analytical model is developed to analyze the seismic performance. Since it is submerged under and influenced by water, the hydrodynamic effect is taken into account by using the hydrodynamic added mass method. To investigate the dynamic characteristics of the RPWP, a modal analysis of the developed analytical model is performed. To evaluate the structural integrity and serviceability of the RPWP, the response spectrum analysis and response time history analysis have been performed under the static load and the seismic load of a safe shutdown earthquake (SSE). Their stresses are analyzed for the structural integrity. The possibility of an impact between the RPWP and the most

  18. Detection of fission products release in the research reactor 'RA' spent fuel storage pool

    Spent fuel resulting from 25 years of operating the 6.5/10 MW thermal heavy water moderated and cooled research reactor RA at the VINCA Institute is presently all stored in the temporary spent fuel storage pool in the basement of the reactor building. In 1984, the reactor was shut down for refurbishment, which for a number of reasons has not yet been completed. Recent investigations show that independent of the future status of the research reactor, safe disposal of the so far irradiated fuel must be the subject of primary concern. The present status of the research reactor RA spent fuel storage pool at the VINCA Institute presents a serious safety problem. Action is therefore initiated in two directions. First, safety of the existing spent fuel storage should be improved. Second, transferring spent fuel into another, presumably dry storage space should be considered. By storing the previously irradiated fuel of the research reactor RA in a newly built storage space, sufficient free space will be provided in the existing spent fuel storage pool for the newly irradiated fuel when the reactor starts operation again. In the case that it would be decided to decommission the research reactor RA, the newly built storage space would provide safe disposal for the fuel irradiated so far

  19. The Fluid Dynamics Analysis of the RSG GAS Reactor's Pool with FLUENT 6

    The RSG-GAS reactor has been operating for eighteen years, and as long as the operation there were many changes on its characteristics. Therefore, some safety analysis must be recalculated and reviewed to ensuring the safety of reactor operation. Safety analysis is carried out by modeling the system and virtually simulation of the severe accident in the model. Accuracy of the analysis is strongly depending on the similarity of the model to actual system to be modeled. One of the data that required in the safety analyses is the fluid flow pattern of reactor pool where the core is placed inside. The data is very useful when the modeling in the comprehensive safety analyses of RSG-GAS is carried out. The fluid flow pattern analysis was tried unsuccessfully, since the modeling was inappropriate. In this research, computational fluid dynamic analysis of the reactor pool is conducted utilizing FLUENT 6. The software solves three dimensionally mass, momentum and energy conservation equations, and also considers the turbulence and the boundaries condition with many model provided on it. The analysis resulted in an appropriate model of the reactor's pool for FLUENT 6 and fluid flow pattern of the RSG-GAS reactor pool. The calculation was converged easily and the resulted flow pattern has strong correlation with the actual condition, therefore the results of the analysis are acceptable. And this successful analysis results have not been achieving previously in RSG-GAS. (author)

  20. Technical outline of a high temperature pool reactor with inherent passive safety features

    Many reactor designers world wide have successfully established technologies for very small reactors (less than 10 MWTH), and technologies for large power reactors (greater than 1000 MWTH), but have not developed small reactors (between 10 MWTH and 1000 MWth) which are safe, economic, and capable of meeting user technical, economic, and safety requirements. This is largely because the very small reactor technologies and the power reactor technologies are not amiable to safe and economic upsizing/downsizing. This paper postulates that new technologies, or novel combinations of existing technologies are necessary to the design of safe and economic small reactors. The paper then suggest a set of requirements that must be satisfied by a small reactor design, and defines a pool reactor that utilizes lead coolant and TRISO fuel which has the potential for meeting these requirements. This reactor, named LEADIR-PS, (an acronym for LEAD-cooled Integral Reactor, Passively Safe) incorporates the inherent safety features of the Modular High Temperature Gas Cooled Reactor (MWGR), while avoiding the cost of reactor and steam generator pressure vessels, and the safety concerns regarding pressure vessel rupture. This paper includes the description of a standard 200MW thermal reactor module based on this concept, called LEADIR-PS 200. (author)

  1. Statistical evaluation of potential damage to the Al(OH)3 layer on nTiO2 particles in the presence of swimming pool and seawater

    Nanosized TiO2 particles (nTiO2) are usually coated with an Al(OH)3 layer when used in sunscreen to shield against the harmful effects of free radicals that are generated when these particles are exposed to UV radiation. Therefore, it is vital to insure the structural stability of these particles in the environment where the protective layer may be damaged and adverse health and environmental effects can occur. This study utilized X-ray analysis (SEM–EDS) to provide a qualitative and semi-quantitative assessment of the chemical and physical characteristics of Al(OH)3-coated original and damaged nTiO2 particles (used in sunscreen lotion formulations) in the presence of both swimming pool and seawater. Also, by utilizing statistical tools, a distribution of Al/Ti (%) on the particle surface was determined and evaluated. It was found that 45 min of treatment with swimming pool and seawater significantly induced the redistribution of Al/Ti (%), which changed the surface characteristics of particles and, therefore, may have induced undesired photo-activity and the consequent formation of free radicals.

  2. Distribution of 16N and 19O in the reactor pool water of the THOR facility

    Radioactive 16N and 19O in the Tsing Hua Open-Pool Reactor, produced from 16O(n,p)16N and 18O(n,γ)19O reactions, respectively, have been measured using a rapid sampling device and gamma-ray spectroscopic systems. The radioactivity of the 7-s half-life 16N and 27-s half-life 19O in the pool water are monitored in the power range from 1 W to 1 MW. The three-dimensional concentration of these radionuclides in the water coolant is also contour mapped down to the detection limit of 10 Bq/l. The spatial distribution of the short-lived radionuclides in the reactor pool, resulting from both the neutron flux distribution and heat transfer characteristics external to the core, is discussed for reactor operation at various power levels

  3. Development, Implementation and Experimental Validations of Activation Products Models for Water Pool Reactors

    Some parameters were obtained both calculations and experiments in order to determined the source of the meaning activation products in water pool reactors. In this case, the study was done in RA-6 reactor (Centro Atomico Bariloche - Argentina).In normal operation, neutron flux on core activates aluminium plates.The activity on coolant water came from its impurities activation and meanly from some quantity of aluminium that, once activated, leave the cladding and is transported by water cooling system.This quantity depends of the 'recoil range' of each activation reaction.The 'staying time' on pool (the time that nuclides are circulating on the reactor pool) is another characteristic parameter of the system.Stationary state activity of some nuclides depends of this time.Also, several theoretical models of activation on coolant water system are showed, and their experimental validations

  4. Basic CFD investigation of decay heat removal in a pool type research reactor

    Safety is one of the most important and desirable characteristic in a nuclear plant. Natural circulation cooling systems are noted for providing passive safety. These systems can be used as mechanism for removing the residual heat from the reactor, or even as the main cooling system for heated sections, such as the core. In this work, a computational fluid-dynamics (CFD) code is used to simulate the process of natural circulation in an open pool research reactor after its shutdown. The physical model studied is similar to the Open Pool Australian Light water reactor (OPAL), and contains the core, cooling pool, reflecting tank, circulation pipes and chimney. For best computing performance, the core region was modeled as a porous media, where the parameters were obtained from a separately detailed CFD analysis. (author)

  5. Experience on Maintenance of Thai Research Reactor's 'Small-Section' Pool

    The reactor pool of TRR-1/M1 has been used since 1962 when the reactor building was constructed. Periodic maintenance of the reactor pool has been conducted by cleaning the pool surface and re-painting with epoxy coating. The TRR-1/M1 pool basically consists of two sections referred as 'large-section' and 'small-section'. The latest re-painting activity of the 'large-section' pool was performed in 2006 but the 'small-section' pool had not been re-painted for more than 10 years. Therefore, to assure that the 'small-section' pool can maintain leak-proof condition, the re-painting of the 'small-section' pool was performed in the early 2012. A project team was organized specially for this project and a detailed execution plan was developed. The project activities include removing foreign objects and highly activated materials from the pool section, cleaning, inspecting, re-painting the pool surface and testing for water leaks. Preparation of the repainting activities had begun 2 years in advance. During the time, the reactor core had been relocated to operate in the large-section pool away from the working area in order to minimize radioactivity. The challenge of this project was to handle 4 sets of highly radioactive bolts and nuts which support the weight of the 'void tank' irradiation facility. These bolts and nuts were made from stainless steel and had been in the flux region since the installation of the 'void tank' irradiation facility approximately 30 years ago. Dose rate measurement at the contacts of these bolts and nuts were found to be in the range of 10 . 20 R/hr. The strategy to minimize the dose rate of the workers to conduct the pool repainting in the area was to remove the bolts and nuts and replace with new ones before entering the area. Special tools were improvised in order to remove the bolts and nuts under water. During the execution of the project, close radiation monitoring was performed by the radiation protection team. The project was conducted

  6. TRIGA reactor spent fuel pool under severe earthquake conditions

    Supplemental criticality safety analysis of a pool type storage for TRIGA spent fuel at 'Jozef Stefan' Institute in Ljubljana, Slovenia, is presented. Previous results (Ravnik, M, Glumac, B., 1996) have shown that subcriticality is not guaranteed for some postulated accidents. To mitigate this deficiency, a study was made about replacing a certain number of fuel elements in the rack with absorber rods (Glumac, B., Ravnik, M., Logar, M., 1997) to lower the supercriticality probability, when the pitch is decreased to contact (as a consequence of a severe earthquake) in a square arrangement. The criticality analysis for the hexagonal contact pitch is presented in this paper, following the same scenario as outlined above. The Monte Carlo computer code MCNP4B with ENDF-B/VI library and detailed three dimensional geometry was used. First, the analysis about the influence of the number of triangular fuel piles on the bottom that could appear, if the fuel rack, made of three segments, disintegrates, is presented. Next, the number of uniformly mixed absorber rods in the lattice needed to sustain the subcriticality of the storage for hexagonal contact pitch is studied. Because of supercriticality possibility due to random mixing of the absorber rods in the case of lattice compaction, a probabilistic study was made in order to sample the probability density functions for random lattice loadings of the absorber rods. The results show that reasonably low probabilities for supercriticality can be achieved even when fresh 12 wt.% standard TRIGA fuel is stored in the spent fuel pool. (orig.)

  7. Effects of nuclear island connected buildings on seismic behaviour of reactor internals in a pool type fast breeder reactor

    The seismic analysis of reactor assembly housing the primary circuit of a typical 500 MWe capacity pool type fast breeder reactor (PFBR) is reported. The reactor assembly is supported on the reactor vault within the nuclear island connected buildings (NICB). The seismic responses, viz. critical displacements, sloshing heights, stresses and strain energy values in the vessels are determined for the reactor assembly by detailed finite element analysis including the fluid-structure interaction and sloshing effects. Analysis is carried out to quantify the effects of inter-connection of the reactor vault with the adjacent buildings under the assumptions that the reactor vault along with reactor assembly is: (1) an isolated structural system from the adjacent buildings within reactor containment building (RCB) and (2) connected with the adjacent civil structures through floor slabs. Analysis indicates that, by inter-connecting the vault with the NICB, there are overall increases of all the governing parameters which decide the seismic design criteria. The significant effects are increases of: (1) radial and axial displacements of core top and absorber rods and vertical accelerations of core subassemblies which are of concern to reactor safety, (2) primary membrane stress intensities for the inner vessel and (3) strain energies developed at the critical portions which can enhance the buckling risks of main vessel, inner vessel and thermal baffles. Hence, it is preferable to isolate the reactor vault, directly constructing from the base raft without inter-connecting it with the NICB, from the seismic loading considerations

  8. Fast determination of octinoxate and oxybenzone uv filters in swimming pool waters by gas chromatography/mass spectrometry after solid-phase microextraction.

    Yılmazcan, Ö; Kanakaki, C; Izgi, B; Rosenberg, E

    2015-07-01

    A fast gas chromatography/mass spectrometry method was developed and validated for the analysis of the potential endocrine disrupters octinoxate and oxybenzone in swimming pool water samples based on the solvent-free solid-phase microextraction technique. The low-pressure gas chromatography/mass spectrometry method used for the fast identification of UV filter substances was compared to a conventional method in terms of sensitivity and speed. The fast method proposed resulted in 2 min runs, leading to an eightfold decrease in the total analysis time and a sevenfold improvement in detection limits. The main parameters affecting the solid-phase microextraction process were also studied in detail and the optimized conditions were as follows: fiber coating, polyacrylate; extraction mode, direct immersion; extraction temperature, 25°C; sample volume, 5 mL; extraction time 45 min; pH 6.5. Under the optimized conditions, a linear response was obtained in the concentration range of 0.5-25 μg/L with correlation coefficients in the range 0.990-0.999. The limits of detection were 0.17-0.29 μg/L, and the recoveries were 80-83%. Combined method uncertainty was assessed and found to be less than 7% for both analytes for concentrations equal to or higher than 5 μg/L. Pool water samples were analyzed to demonstrate the applicability of the proposed method. Neither octinoxate nor oxybenzone were detected in the swimming pool water samples at concentrations above the respective limits of detection. PMID:25931007

  9. Garigliano Nuclear Power Plant, Italy: Decontamination and Rearranging of Reactor Canal and Spent Fuel Pool

    Garigliano nuclear power plant was a 506 MW(th), first generation, dual cycle BWR. It started operation in 1964 and finally shut down in 1978, following the discovery of serious damage to a secondary steam generator. This section describes decontamination activities carried out in 1991–1993 in preparation for safe enclosure of Garigliano reactor building.1 Activities were carried out after completion of spent fuel transport off-site (1985–1987). A schematic of the spent fuel pool and adjacent areas is provided. Decontamination activities included the following: (a) Agitation and resuspension of pool sediments using water jets and water filtration. (b) Lowering of water level and parallel decontamination of pool walls with high pressure water jets of approximately 700 kg/cm2. (c) Removal, decontamination and interim storage on gangways of equipment located on the pool south-east wall. (d) Removal, decontamination and storage of the fuel transport container platform. (e) Removal of four fuel racks to their pool wall bearings, decontamination and transfer to the fresh fuel room. (f) Decontamination of the vessel head platform, removal from the reactor canal, brushing and coating to allow preservation and fixing of loose contamination. Eventually, this component was placed back in the reactor canal. (g) Construction in the reactor canal of an interim structure supporting fuel racks. At the completion of the work, this structure was dismounted, decontaminated and removed. (h) Removal of fuel racks (five at a time) to their pool wall bearings, decontamination and interim storage in the reactor canal. (i) Gradual lowering of the pool water level to some 50 cm from the pool floor and parallel decontamination of fixed structures and walls. (j) Discovery by visual inspection and radiological checks, of activated components on the floor of the pool. Retrieval of all this material, segmentation as needed, temporary storage in containers and later transfer to the high

  10. Swim Free. A 10 Day Program of Aquatic Exercises Adapted from Life in the Waterworld.

    Eberhardt, Lorraine; Sanborn, Laura

    The completely waterproof book contains instructions for an alternative form of swimming exercises based on the movements of 19 water creatures. The exercises can be used by groups or individuals to enhance training programs, to serve as part of a structured synchronized swimming program, or to supplement recreational activities. The book provides…

  11. Fast neutron spectrum in the reflector of swimming pool reactor behind metallics slabs

    The large perturbations of fast neutron spectrum were measured behind lead, aluminium and iron slabs in the Siloette reflector at the CENG. The neutron slowing down is chiefly depending of the inelastic reaction. The reaction cross section increases with energy; a spectrum softening is deduced. This is verified. We tried to determine the spectrum shape by calculation to fit the measurements. Calculations were firstly made in unidimensional geometry by the NIOBE transport equation resolution code and by the SANE Monte-Carlo code. The results does not agree with the experimental determined values. Finally a semi-empirical method for studying a tridimensional geometry was chosen. We have obtained calculation results in a perfect agreement with measurements. The method is described. (author)

  12. TRIGA reactor spent fuel pool under severe earthquake conditions

    Logar, M. [Univ. of Maribor (Slovenia). Fac. of Elec. Eng.; Glumac, B.; Maucec, M. [`Jozef Stefan` Institute, Jamova 39, POB 100, 1111 Ljubljana (Slovenia)

    1998-07-01

    Supplemental criticality safety analysis of a pool type storage for TRIGA spent fuel at `Jozef Stefan` Institute in Ljubljana, Slovenia, is presented. Previous results (Ravnik, M, Glumac, B., 1996) have shown that subcriticality is not guaranteed for some postulated accidents. To mitigate this deficiency, a study was made about replacing a certain number of fuel elements in the rack with absorber rods (Glumac, B., Ravnik, M., Logar, M., 1997) to lower the supercriticality probability, when the pitch is decreased to contact (as a consequence of a severe earthquake) in a square arrangement. The criticality analysis for the hexagonal contact pitch is presented in this paper, following the same scenario as outlined above. The Monte Carlo computer code MCNP4B with ENDF-B/VI library and detailed three dimensional geometry was used. First, the analysis about the influence of the number of triangular fuel piles on the bottom that could appear, if the fuel rack, made of three segments, disintegrates, is presented. Next, the number of uniformly mixed absorber rods in the lattice needed to sustain the subcriticality of the storage for hexagonal contact pitch is studied. Because of supercriticality possibility due to random mixing of the absorber rods in the case of lattice compaction, a probabilistic study was made in order to sample the probability density functions for random lattice loadings of the absorber rods. The results show that reasonably low probabilities for supercriticality can be achieved even when fresh 12 wt.% standard TRIGA fuel is stored in the spent fuel pool. (orig.) 7 refs.

  13. Quantitative analysis of gamma ray emitting radionuclide in reactor pool water of HANARO

    Kim, Myong Seop; Kim, Hee Gon; Ahn, Guk Hoon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2008-11-15

    The species and concentrations of the radionuclide in the primary coolant of HANARO were analyzed by using the gamma ray spectroscopy. The full energy peak efficiency for the volume source was calibrated as function of the photon energy for an HRGs detector. The primary coolant of HANARO was picked at the primary coolant purification system, and the water at the upper part of the reactor pool was taken at about 20cm under the pool surface. In the primary coolant, the concentrations of Na-24, Mg-27 and Al-28 were much higher than those of other nuclide, and they were in 1{approx}6x10'6'Bq/liter. Their origins were radiative reactions of aluminium used as the structure material and cladding of the nuclear fuel. The concentrations of Xe-138 and Xe-133 were relatively higher than those of other fission fragments. The source of the fission fragments in the coolant was the surface contamination of the nuclear fuel by uranium. Ar-41, Ce-141, Na-24 and Xe-133 were detected in the water at the upper part of the reactor pool. Na-24 was the main source of the pool top radiation level, and Xe-133 and Ar-41 were the main gaseous radionuclide released through the reactor pool surface.

  14. Quantitative analysis of gamma-ray emitting radionuclide in reactor pool water of HANARO

    Kim, Myong-Seop; Kim, Hee-Gon; Ahn, Guk-Hoon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2008-11-15

    The species and concentrations of the radionuclide in the primary coolant of HANARO were analyzed by using the gamma-ray spectroscopy. The full-energy peak efficiency for the volume source was calibrated as a function of the photon energy for an HPGe detector. The primary coolant of HANARO was picked at the primary coolant purification system, and the water at the upper part of the reactor pool was taken at about 20 cm under the pool surface. In the primary coolant, the concentrations of Na-24, Mg-27 and Al-28 were much higher than those of other nuclide, and they were in 1-6 x 10{sup 6} Bq/liter. Their origins were radiative reactions of aluminium used as the structure material and cladding of the nuclear fuel. The concentrations of Xe-138 and Xe-133 were relatively higher than those of other fission fragments. The source of the fission fragments in the coolant was the surface contamination of the nuclear fuel by uranium. Ar-41, Ce-141, Na-24 and Xe-133 were detected in the water at the upper part of the reactor pool. Na-24 was the main source of the pool top radiation level, and Xe-133 and Ar-41 were the main gaseous radionuclide released through the reactor pool surface.

  15. Quantitative analysis of gamma ray emitting radionuclide in reactor pool water of HANARO

    The species and concentrations of the radionuclide in the primary coolant of HANARO were analyzed by using the gamma ray spectroscopy. The full energy peak efficiency for the volume source was calibrated as function of the photon energy for an HRGs detector. The primary coolant of HANARO was picked at the primary coolant purification system, and the water at the upper part of the reactor pool was taken at about 20cm under the pool surface. In the primary coolant, the concentrations of Na-24, Mg-27 and Al-28 were much higher than those of other nuclide, and they were in 1∼6x10'6'Bq/liter. Their origins were radiative reactions of aluminium used as the structure material and cladding of the nuclear fuel. The concentrations of Xe-138 and Xe-133 were relatively higher than those of other fission fragments. The source of the fission fragments in the coolant was the surface contamination of the nuclear fuel by uranium. Ar-41, Ce-141, Na-24 and Xe-133 were detected in the water at the upper part of the reactor pool. Na-24 was the main source of the pool top radiation level, and Xe-133 and Ar-41 were the main gaseous radionuclide released through the reactor pool surface

  16. Storage of water reactor spent fuel in water pools. Survey of world experience

    Following discharge from a nuclear reactor, spent fuel has to be stored in water pools at the reactor site to allow for radioactive decay and cooling. After this initial storage period, the future treatment of spent fuel depends on the fuel cycle concept chosen. Spent fuel can either be treated by chemical processing or conditioning for final disposal at the relevant fuel cycle facilities, or be held in interim storage - at the reactor site or at a central storage facility. Recent forecasts predict that, by the year 2000, more than 150,000 tonnes of heavy metal from spent LWR fuel will have been accumulated. Because of postponed commitments regarding spent fuel treatment, a significant amount of spent fuel will still be held in storage at that time. Although very positive experience with wet storage has been gained over the past 40 years, making wet storage a proven technology, it appears desirable to summarize all available data for the benefit of designers, storage pool operators, licensing agenices and the general public. Such data will be essential for assessing the viability of extended water pool storage of spent nuclear fuel. In 1979, the International Atomic Energy Agency and the Nuclear Energy Agency of the OECD jointly issued a questionnaire dealing with all aspects of water pool storage. This report summarizes the information received from storage pool operators

  17. CFD aided analysis of a scaled down model of the Brazilian Multipurpose Reactor (RMB) pool

    Research reactors are commonly built inside deep pools that provide radiological and thermal protection and easy access to its core. Reactors with thermal power in the order of MW usually use an auxiliary thermal-hydraulic circuit at the top of its pool to create a purified hot water layer (HWL). Thermal-hydraulic analysis of the flow configuration in the pool and HWL is paramount to insure radiological protection. A useful tool for these analyses is the application of CFD (Computational Fluid Dynamics). To obtain satisfactory results using CFD it is necessary the verification and validation of the CFD numerical model. Verification is divided in code and solution verifications. In the first one establishes the correctness of the CFD code implementation and in the former estimates the numerical accuracy of a particular calculation. Validation is performed through comparison of numerical and experimental results. This paper presents a dimensional analysis of the RMB (Brazilian Multipurpose Reactor) pool to determine a scaled down experimental installation able to aid in the HWL numerical investigation. Two CFD models were created one with the same dimensions and boundary conditions of the reactor prototype and the other with 1/10 proportion size and boundary conditions set to achieve the same inertial and buoyant forces proportions represented by Froude Number between the two models. Results comparing the HWL thickness show consistence between the prototype and the scaled down model behavior. (author)

  18. CFD aided analysis of a scaled down model of the Brazilian Multipurpose Reactor (RMB) pool

    Schweizer, Fernando L.A.; Lima, Claubia P.B.; Costa, Antonella L.; Veloso, Maria A.F., E-mail: ando.schweizer@gmail.com, E-mail: claubia@nuclear.ufmg.br, E-mail: antonella@nuclear.ufmg.br, E-mail: mdora@nuclear.ufmg.br [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Santos, Andre A.C.; Costa, Antonio C.L., E-mail: aacs@cdtn.br, E-mail: aclc@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN/-MG), Belo Horizonte, MG (Brazil)

    2013-07-01

    Research reactors are commonly built inside deep pools that provide radiological and thermal protection and easy access to its core. Reactors with thermal power in the order of MW usually use an auxiliary thermal-hydraulic circuit at the top of its pool to create a purified hot water layer (HWL). Thermal-hydraulic analysis of the flow configuration in the pool and HWL is paramount to insure radiological protection. A useful tool for these analyses is the application of CFD (Computational Fluid Dynamics). To obtain satisfactory results using CFD it is necessary the verification and validation of the CFD numerical model. Verification is divided in code and solution verifications. In the first one establishes the correctness of the CFD code implementation and in the former estimates the numerical accuracy of a particular calculation. Validation is performed through comparison of numerical and experimental results. This paper presents a dimensional analysis of the RMB (Brazilian Multipurpose Reactor) pool to determine a scaled down experimental installation able to aid in the HWL numerical investigation. Two CFD models were created one with the same dimensions and boundary conditions of the reactor prototype and the other with 1/10 proportion size and boundary conditions set to achieve the same inertial and buoyant forces proportions represented by Froude Number between the two models. Results comparing the HWL thickness show consistence between the prototype and the scaled down model behavior. (author)

  19. Cost estimates of operating onsite spent fuel pools after final reactor shutdown

    This report presents estimates of the annual costs of operating spent fuel pools at nuclear power stations after the final shutdown of one or more onsite reactors. Its purpose is to provide basic spent fuel storage cost information for use in evaluating DOE's reference nuclear waste management system, as well as alternate systems. The basic model of an independent spent fuel storage installation (ISFSI) used in this study was based on General Electric Corporation's Morris Operation and was modified to reflect mean storage capabilities at an unspecified, or ''generic,'' US reactor site. Cost data for the model came from several sources, including both operating and shutdown nuclear power stations and existing ISFSIs. Duke Power Company has estimated ISFSI costs based on existing spent fuel storage costs at its nuclear power stations. Similarly, nuclear material handling facilities such as the Morris Operation, the West Valley Demonstration Project, and the retired Humbolt Bay nuclear power station have compiled spent fuel storage cost data based on years of operating experience. Consideration was given to the following factors that would cause operating costs to vary among pools: (1) The number of spent fuel pools at a given reactor site; (2) the number of operating and shutdown reactors onsite; (3) geographic location; and (4) pool storage capacity. 10 ref., 6 figs., 7 tabs

  20. Progress activities of reactor utilization in 2000

    Charoen, Sakda [Office of Atomic Energy for Peace, Bangkok (Thailand)

    2003-03-01

    Thai Research Reactor - 1/Modification 1(TRR-1/M1) is a multipurpose research reactor with nominal power of 2 MW. The reactor is a swimming pool type, cooled and moderate with light water, using the LEU-fuel. The reactor has been utilized for radioisotope production, neutron beam experiments and reactor physic experiments. The reactor operation data and reactor utilization in 2000 are presented. (author)

  1. Progress activities of reactor utilization in 2000

    Thai Research Reactor - 1/Modification 1(TRR-1/M1) is a multipurpose research reactor with nominal power of 2 MW. The reactor is a swimming pool type, cooled and moderate with light water, using the LEU-fuel. The reactor has been utilized for radioisotope production, neutron beam experiments and reactor physic experiments. The reactor operation data and reactor utilization in 2000 are presented. (author)

  2. Gamma ray shielding calculation benchmark exercise comparison of Monte Carlo simulation and experimental methods of gamma radiation field mapping in the pool of Apsara reactor

    Apsara is a swimming pool type research reactor loaded with Highly Enriched Uranium (HEU) fuel. The reactor is designed for a maximum power level of 1 MW and is normally operated up to 400 KW. The pool water serves as coolant, moderator and reflector besides providing shielding. In addition, graphite and beryllium oxide incased in aluminum boxes are used as in-core reflector. The core is mounted on a square grid of aluminum, 56x56x15 cm with 49 holes on a 7 x 7 square lattice (77 mm pitch), containing fuel elements, control elements, reflectors, irradiation tubes, neutron source and fission counter. This study served in validation of the experimental measurements conducted using GM counter based detector and diode based detectors. In addition, the comparison provided a confirmation of the accuracy of the radiation transport simulation techniques used for dose rate evaluation in case of complex source geometries and large shield materials present. The experimental measurements thus served in bench marking the simulation methods adopted for radiation transport used to arrive at reactor physics and radiological safety parameters of interest

  3. Effect of ozonation of swimming pool water on formation of volatile disinfection by-products - A laboratory study

    Hansen, Kamilla Marie Speht; Spiliotopoulou, Aikaterini; Cheema, Waqas Akram;

    2016-01-01

    approximated 17-19 min in all samples. Subsequent chlorination revealed ozone removed reactivity of dissolved organic carbon toward chlorine for tap and polluted pool water, decreasing formation rate of trihalomethanes (TTHM). In pool water higher rates of TTHM formation was observed after the initial ozone...... dosage, however this decreased with subsequent treatments. For tap and polluted pool water, ozone reacted directly with the pollutants resulting in a short ozone half-life, removing reactivity towards chlorine oxidation and preventing TTHM production. Conversely for pool water samples, due to the long...... half-life of ozone, the molecule decomposed to hydroxyl radicals. These in turn reacted with aqueous organic matter increasing chlorine reactivity and rates of TTHM formation. Formation of other non-regulated volatile byproducts (e.g. dichloracetonitrile, trichlorpropanone and trichloronitromethane...

  4. Science-policy interface in transformative adaptive flood risk management - decision-making in Austria

    Thaler, Thomas; Attems, Marie-Sophie; Rauter, Magdalena; Fuchs, Sven

    2016-04-01

    Facing the challenges of climate change, this paper aims to analyse and to evaluate the multiple use of flood alleviation schemes with respect to social transformation in communities exposed to flood hazards in Europe. The overall goals are: (1) the identification of indicators and parameters necessary for strategies to increase societal resilience, (2) an analysis of the institutional settings needed for societal transformation, and (3) perspectives of changing divisions of responsibilities between public and private actors necessary to arrive at more resilient societies. As such, governance is done by people interacting and defining risk mitigation measures as well as climate change adaptation are therefore simultaneously both outcomes of, and productive to, public and private responsibilities. Building off current knowledge this paper focussed on different dimensions of adaptation and mitigation strategies based on social, economic and institutional incentives and settings, centring on the linkages between these different dimensions and complementing existing flood risk governance arrangements. As such, the challenges of adaptation to flood risk will be tackled by converting scientific frameworks into practical assessment and policy advice. This paper used the Formative Scenario Analysis (FSA) as a method to construct well-defined sets of assumptions to gain insight into a system and its potential future development, based on qualitatively assessed impact factors and rated quantitative relations between these factors, such as impact and consistency analysis. The purpose of this approach was to develop scenarios, where participations develop their own strategies how to implement a transformative adaptation strategy in flood risk management. In particular, the interaction between researcher, the public and policy makers was analysed. Challenges and limitations were assessed, such as benefits on costs of adaptation measures, for the implementation of visions to

  5. Spectacular energy technology: Panorama-Sauna Holzweiler. KfW funds indoor swimming pools as 'process heat'; Energetisch spektakulaer: Panorama-Sauna Holzweiler. KfW foerdert Schwimmbaeder als 'Prozesswaerme'

    Meissner, Rolf

    2008-11-15

    The ''Panorama-Sauna'' at Grafschaft is a big indoor swimming pool and Sauna centre in a rural region not far from Cologne and Koblenz. The charm of this spectacular solar project is in its minimalism. Conventional solar thermal power systems, in contrast, tend to be complex and prone to failure. (orig.)

  6. Perseveration on place reversals in spatial swimming pool tasks: further evidence for place learning in hippocampal rats.

    Whishaw, I Q; Tomie, J A

    1997-01-01

    Animals with damage to the fimbria-fornix (FF) or cells of the hippocampus (HIP) can learn a place problem but cannot learn matching-to-place problems, which feature a series of place "reversals." The two experiments described in the present report were designed to examine the causes of impairment on reversal learning. In experiment 1, control, HIP, and FF groups were trained to asymptote on a place problem, and then the location of the platform was moved. Control rats learned the reversal response more quickly than the initial response; the HIP rats learned both problems at the same rate. Swim analysis showed that the impairment in the lesion group on the reversal response was aggravated by perseverative returns to the first learned place. In experiment 2, control and FF groups were trained on a task in which the platform was visible on three daily trials and hidden on one daily trial. After 10 days, the platforms were moved. In the reversal response, the FF group showed enhanced performance on the cue trials and severely impaired performance on the place trials relative to initial learning and control performance. Swim analysis showed that FF rats perseverated on the initial place response in place trials. These experiments provide further evidence for place learning in hippocampal rats and show that perseverative responses contribute to impairments in new learning. The results are discussed in relation to the idea that the hippocampus mediates spatial mapping and/or uses self-movement cues to solve spatial problems. PMID:9287076

  7. Lung hyperpermeability and asthma prevalence in schoolchildren: unexpected associations with the attendance at indoor chlorinated swimming pools

    Bernard, Alfred; Carbonnelle, Sylviane; Michel, O; Higuet, S; de Burbure, Claire; Buchet, Jean-Pierre; Hermans, Cédric; Dumont, Xavier; Doyle, I

    2003-01-01

    AIMS: To study whether exposure to nitrogen trichloride in indoor chlorinated pools may affect the respiratory epithelium of children and increase the risk of some lung diseases such as asthma. METHODS: In 226 healthy children, serum surfactant associated proteins A and B (SP-A and SP-B), 16 kDa Clara cell protein (CC16), and IgE were measured. Lung specific proteins were measured in the serum of 16 children and 13 adults before and after exposure to NCl(3) in an indoor chlorinated pool. Rela...

  8. Design of neutron radiography facility in pool for the reactor RA-10

    RA-10 project consists in the design and construction of a multipurpose reactor for multiple applications, including radioisotopes production, material testing and an in pool facility for neutron imaging. Neutron imaging is a powerful tool for studies of materials and offer several advantages among other attenuation-based techniques. In this study mechanical and neutronic requirements for the RA-10 in pool neutron imaging facility are described. The MCNP neutronic model and the mechanical design satisfying these requirements in a first engineering stage are described. (author)

  9. Implementation and adaption of the Computer Code ECOSYS/EXCEL for Austria as OECOSYS/EXCEL

    During 1989, under contract to the Austrian Chamber of the Federal Chancellor, department VII, the radioecological forecast model OECOSYS was implemented by the Austrian Research Centre Seibersdorf on a VAX computer using VAX Fortran. OECOSYS allows the prediction of the consequences after a large scale contamination event. During 1992, under contract to the Austrian Federal Ministry of Health, Sports and Consumer Protection, department III OECOSYS - in the version of 1989 - was implemented on PC's in Seibersdorf and the Ministry using OS/2 and Microsoft -Fortran. In March 1993, the Ministry ordered an update which had become necessary and the evaluation of two exercise scenarios. Since that time the prognosis model with its auxiliary program and communication facilities is kept on stand-by and yearly exercises are performed to maintain its readiness. The current report describes the implementation and adaption to Austrian conditions of the newly available EXCEL version of the German ECOSYS prognosis model as OECOSYS. (author)

  10. Experimental study of prompt neutron decay constant α for 300# pool reactor under mixed core

    The experimental study of prompt neutron decay constant α for 300# pool reactor under mixed core was carried out through a suit of reactor power spectral density measurement system. The two channel continuous current signals of neutron in the reactor were acquired by ionization chamber DL129 which was symmetrically putted in reactor core. The power spectral density, for two channel signals, was computed using the application program of data acquirement and data process analysis. Finally, by using the non-linear least squares method, the prompt neutron decay constant α was fitted. By comparison, the experimental results well accord to the theory calculation within the error range. The deviation can meet the actual need of project. (authors)

  11. Overview of pool hydraulic design of Indian prototype fast breeder reactor

    K Velusamy; P Chellapandi; S C Chetal; Baldev Raj

    2010-04-01

    Thermal hydraulics plays an important role in the design of liquid metal cooled fast breeder reactor components, where thermal loads are dominant. Detailed thermal hydraulic investigations of reactor components considering multi-physics heat transfer are essential for choosing optimum designs among the various possibilities. Pool hydraulics is multi-dimensional in nature and simple one-dimensional treatment for the same is often inadequate. Computational Fluid Dynamics (CFD) plays a critical role in the design of pool type reactors and becomes an increasingly popular tool, thanks to the advancements in computing technology. In this paper, thermal hydraulic characteristics of a fast breeder reactor, design limits and challenging thermal hydraulic investigations carried out towards successful design of Indian Prototype Fast Breeder Reactor (PFBR) that is under construction, are highlighted. Special attention is paid to phenomena like thermal stratification, thermal stripping, gas entrainment, inter-wrapper flow in decay heat removal and multiphysics cellular convection. The issues in these phenomena and the design solutions to address them satisfactorily are elaborated. Experiments performed for special phenomena, which are not amenable for CFD treatment and experiments carried out for validation of the computer codes have also been described.

  12. Engineering, safety, and economic evaluations of ASPIRE [Advanced Safe Pool Immersed REactor

    A preconceptual design of a tokamak fusion reactor concept called ASPIRE (Advanced Safe Pool Immersed REactor) has been developed. This concept provides many of the attractive features that are needed to enhance the capability of fusion to become the power generation technology for the 21st century. Specifically, these features are: inherent safety, low pressure, environmental compatibility, moderate unit size, high availability, high thermal efficiency, simplicity, low radioactive inventory, Class C radioactive waste disposal, and low cost of electricity. We have based ASPIRE on a second stability tokamak. However, the concept is equally applicable to a first stability tokamak or to most other magnetic fusion systems

  13. Simulation of the Gamma Dose Rate in Loss of Pool Water Accident of the Second Egyptian Research Reactor ETRR-2

    The Second Egyptian Research Reactor ETRR-2, is a pool type reactor, a sudden loss of pool water resulting of leaving the core region un-covered. The reactor core is surrounded by chimney chambers whose water is isolated from pool water. This accident would lead to significant external dose. A model is developed and is used to calculate the dose rates for key access and traffic plans from indirect line of sight of the core have a maximum dose rate. The model developed uses the discrete ordinate method as implemented in the code DOT 3.5

  14. Effect of pH on the formation of disinfection byproducts in swimming pool water – Is less THM better?

    Hansen, Kamilla Marie Speht; Willach, Sarah; Antoniou, Maria; Mosbæk, Hans; Albrechtsen, Hans-Jørgen; Andersen, Henrik Rasmus

    2012-01-01

    This study investigated the formation and predicted toxicity of different groups of disinfection byproducts (DBPs) from human exudates in relation to chlorination of pool water at different pH values. Specifically, the formation of the DBP groups trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs) and trichloramine (NCl3), resulting from the chlorination of body fluid analog, were investigated at 6.0 ≤ pH ≤ 8.0. Either the initial concentration of active chorine or free ...

  15. Adaptive nonlinear control for a research reactor

    Linearization by feedback of states is based on the idea of transform the nonlinear dynamic equation of a system in a linear form. This linear behavior can be achieve well in a complete way (input state) or in partial way (input output). This can be applied to systems of single or multiple inputs, and can be used to solve problems of stabilization and tracking of references trajectories. Comparing this method with conventional ones, linearization by feedback of states is exact in certain region of the space of state, instead of linear approximations of the equations in a certain point of the operation. In the presence of parametric uncertainties in the model of the system, the introduction of adaptive schemes provide a type toughness to the control system by nonlinear feedback, which gives as result the eventual cancellation of the nonlinear terms in the dynamic relationship between the output and the input of the auxiliary control. In the same way, it has been presented the design of a nonlinearizing control for the non lineal model of a TRIGA Mark III type reactor, with the aim of tracking a predetermined power profile. The asymptotic tracking of such profile is, at the present moment, in the stage of verification by computerized simulation the relative easiness in the design of auxiliary variable of control, as well as the decoupling action of the output variable, make very attractive the utilization of the method herein presented. (Author)

  16. Eddy current testing of PWR fuel pencils in the pool of the Osiris reactor

    A nondestructive testing bench is described. It is devoted to examination of high residual power fuel pencils without stress on the cladding nor interference with cooling. Guiding by fluid bearings decrease the background noise. Scanning speed is limited only by safety criteria and data acquisition configuration. Simultaneous control of various parameters is possible. Associated to an irradiation loop, loaded and unloaded in a reactor swinning pool, this bench can follow fuel pencil degradation after each irradiation cycle

  17. Conceptual design of reactor TRIGA PUSPATI (RTP) spent fuel pool cooling system

    After undergo about 30 years of safe operation, Reactor TRIGA PUSPATI (RTP) was planned to be upgraded to ensure continuous operation at optimum safety condition. In the meantime, upgrading is essential to get higher flux to diversify the reactor utilization. Spent fuel pool is needed for temporary storage of the irradiated fuel before sending it back to original country for reprocessing, reuse after the upgrading accomplished or final disposal. The irradiated fuel elements need to be secure physically with continuous cooling to ensure the safety of the fuels itself. The decay heat probably still exist even though the fuel elements not in the reactor core. Therefore, appropriate cooling is required to remove the heat produced by decay of the fission product in the irradiated fuel element. The design of spent fuel pool cooling system (SFPCS) was come to mind in order to provide the sufficient cooling to the irradiated fuel elements and also as a shielding. The spent fuel pool cooling system generally equipped with pumps, heat exchanger, water storage tank, valve and piping. The design of the system is based on criteria of the primary cooling system. This paper provides the conceptual design of the spent fuel cooling system. (author)

  18. Fuel Burnup and Fuel Pool Shielding Analysis for Bushehr Nuclear Reactor VVER-1000

    Hadad, Kamal; Ayobian, Navid

    Bushehr Nuclear power plant (BNPP) is currently under construction. The VVER-1000 reactor will be loaded with 126 tons of about 4% enriched fuel having 3-years life cycle. The spent fuel (SF) will be transferred into the spent fuel pool (SPF), where it stays for 8 years before being transferred to Russia. The SPF plays a crucial role during 8 years when the SP resides in there. This paper investigates the shielding of this structure as it is designed to shield the SF radiation. In this study, the SF isotope inventory, for different cycles and with different burnups, was calculated using WIMS/4D transport code. Using MCNP4C nuclear code, the intensity of γ rays was obtained in different layers of SFP shields. These layers include the water above fuel assemblies (FA) in pool, concrete wall of the pool and water laid above transferring fuels. Results show that γ rays leakage from the shield in the mentioned layers are in agreement with the plant's PSAR data. Finally we analyzed an accident were the water height above the FA in the pool drops to 47 cm. In this case it was observed that exposure dose above pool, 10 and 30 days from the accident, are still high and in the levels of 1000 and 758 R/hr.

  19. Adapting Dynamic Mathematical Models to a Pilot Anaerobic Digestion Reactor

    F. Haugen, R. Bakke, and B. Lie

    2013-04-01

    Full Text Available A dynamic model has been adapted to a pilot anaerobic reactor fed diarymanure. Both steady-state data from online sensors and laboratory analysis anddynamic operational data from online sensors are used in the model adaptation.The model is based on material balances, and comprises four state variables,namely biodegradable volatile solids, volatile fatty acids, acid generatingmicrobes (acidogens, and methane generating microbes (methanogens. The modelcan predict the methane gas flow produced in the reactor. The model may beused for optimal reactor design and operation, state-estimation and control.Also, a dynamic model for the reactor temperature based on energy balance ofthe liquid in the reactor is adapted. This model may be used for optimizationand control when energy and economy are taken into account.

  20. Design guide for Category III reactors: pool type reactors. [US DOE

    Brynda, W J; Lobner, P R; Powell, R W; Straker, E A

    1978-11-01

    The Department of Energy (DOE) in the ERDA Manual requires that all DOE-owned reactors be sited, designed, constructed, modified, operated, maintained, and decommissioned in a manner that gives adequate consideration to health and safety factors. Specific guidance pertinent to the safety of DOE-owned reactors is found in Chapter 0540 of the ERDA Manual. The purpose of this Design Guide is to provide additional guidance to aid the DOE facility contractor in meeting the requirement that the siting, design, construction, modification, operation, maintenance, and decommissioning of DOE-owned reactors be in accordance with generally uniform standards, guides, and codes which are comparable to those applied to similar reactors licensed by the Nuclear Regulatory Commission (NRC). This Design Guide deals principally with the design and functional requirement of Category III reactor structures, components, and systems.

  1. Equipment and methods for examinations of fuel rods in the MIR reactor storage pool

    A wide range of tests of fuel rods and structural materials of water-cooled power reactors is performed in the loop facilities (LFs) of the MIR reactor. Depending on the objectives and tasks of different experiments, the performance of periodical interim examinations of irradiated items is required. However, as a result of some circumstances, it is not always possible to conduct them in hot cells. In this context, JSC 'SSC RIAR' has developed the equipment for interim examinations of fuel rods and design components of the experimental fuel assemblies (EFAs) in the MIR reactor storage pool (SP). Besides, this equipment can be used for cleaning of the examined items from surface deposits prior to the measurements. The paper describes the main characteristics and capabilities of the developed equipment, methodical aspects of the performed interim examinations, as well as some experimental results obtained using this equipment. In future, its upgrade is planned. (author)

  2. Commissioning of the Open Pool Australian Lightwater (OPAL) research reactor - A health physics perspective

    During 2006 and 2007 the Australian Nuclear Science and Technology Organisation (ANSTO) commissioned OPAL, a 20 MW open pool Research Reactor. This commissioning involved three stages; Stage A, testing the reactors systems prior to fuel loading, Stage B, first loading of fuel, achieving first criticality, reactor characterisation and systems testing up to 400kW, and Stage C, raising the power of the reactor in steps, up to its full operating power of 20MW. Prior to and following fuel loading a series of radiation measurements were made throughout the plant. These included dose rates, radioactivity in air, on surfaces and in cooling and shielding liquids. Installed continuous monitoring and portable equipment were used. Health physics measurements were repeated at increasing reactor power levels to check engineering design features and design of plant for radiation protection aspects. A Radiation Protection Plan and associated monitoring programs were implemented, including establishing and maintaining area, task and personnel monitoring regimes in the facility. Health Physics assessments and advice at each stage, played a major role in this commissioning process. This paper discusses the health physics experience of commissioning the OPAL Research Reactor and describes health physics results, actions taken and lessons learned during commissioning. (author)

  3. Commissioning of the Open Pool Australian Light water (OPAL) research reactor: a health physics perspective

    During 2006 and 2007 the Australian Nuclear Science and Technology Organisation (ANSTO) commissioned OPAL, a 20 MW open pool Research Reactor. This commissioning involved three stages: Stage A: testing the reactors systems prior to fuel loading; Stage B: first loading of fuel, achieving first criticality, reactor characterisation and systems testing up to 400 kw; and Stage C: raising the power of the reactor in steps, up to its full operating power of 20 MW. Prior to and following fuel loading a series of radiation measurements were made throughout the plant. These included dose rates, radioactivity in air, on surfaces and in cooling and shielding liquids. Installed continuous monitoring and portable equipment were used. Health physics measurements were repeated at increasing reactor power levels to check engineering design features and design of plant for radiation protection aspects. A Radiation Protection Plan and associated monitoring programs were implemented, including establishing and maintaining area, task and personnel monitoring regimes in the facility. Health Physics assessments and advice at each stage, played a major role in this commissioning process. This paper discusses the health physics experience of commissioning the OPAL Research Reactor and describes health physics results, actions taken and lessons learned during commissioning. (author)

  4. Numerical simulation of sodium pool fires in liquid metal-cooled fast breeder reactor

    In Liquid Metal-Cooled Fast Breeder Reactor (LMFBR), the leakage of sodium can result in sodium fires. Due to sodium's high chemical reactivity in contact with air and water, sodium fires will lead to an immediate increase of the air temperature and pressure in the containment. This will harm the integrity of the containment. In order to estimate and foresee the sequence of this accident, or to prevent the accident and alleviate the influence of the accident, it is necessary to develop programs to analyze such sodium fire accidents. Based on the work of predecessors, flame sheet model is produced and used to analyze sodium pool fire accidents. Combustion model and heat transfer model are included and expatiated. And the comparison between the analytical and experimental results shows the program is creditable and reasonable. This program is more realistic to simulate the sodium pool fire accidents and can be used for nuclear safety judgement. (authors)

  5. Effect of pH on the formation of disinfection byproducts in swimming pool water--is less THM better?

    Hansen, Kamilla M S; Willach, Sarah; Antoniou, Maria G; Mosbæk, Hans; Albrechtsen, Hans-Jørgen; Andersen, Henrik R

    2012-12-01

    This study investigated the formation and predicted toxicity of different groups of disinfection byproducts (DBPs) from human exudates in relation to chlorination of pool water at different pH values. Specifically, the formation of the DBP groups trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs) and trichloramine (NCl(3)), resulting from the chlorination of body fluid analog, were investigated at 6.0 ≤ pH ≤ 8.0. Either the initial concentration of active chorine or free chlorine was kept constant in the tested pH range. THM formation was reduced by decreasing pH but HAN, and NCl(3) formation increased at decreasing pH whereas the formation of HAAs remained constant. Under our experimental conditions, the formation of NCl(3) (suspected asthma inducing compound) at pH = 6.0 was an order of magnitude higher than at pH = 7.5. Furthermore, the effect of the presence of bromide on DBP formation was investigated and found to follow the same pH dependency as without bromide present, with the overall DBP formation increasing, except for HAAs. Estimation of genotoxicity and cytotoxicity of the chlorinated human exudates showed that among the quantified DBP groups, HAN formation were responsible for the majority of the toxicity from the measured DBPs in both absence and presence of bromide. PMID:23026126

  6. Local heat transfer from the corium melt pool to the boiling water reactor pressure vessel wall

    The present study considers in-vessel accident progression after core melt relocation to the lower head of a Boiling Water Reactor (BWR) and formation of a melt pool containing a forest of Control Rod Guide Tubes (CRGTs) cooled by purging flows. Descending streams of melt that flow along cooled surfaces of CRGT, and impinge on the bottom surface of the vessel wall can significantly increase local heat transfer. The area of enhanced heat transfer enlarges with decreasing of the melt Prandtl (Pr) number, while the peaking value of the heat transfer coefficient is a non-monotone function of Pr number. The melt Pr number depends on the melt composition (fractions of metallic and oxidic melt components) and thus is inherently uncertain parameter of the core melting and relocation scenarios. The effect of Pr number in the range of 1.02 - 0.03 on the local and integral thermal loads on the vessel wall is examined using Computational Fluid Dynamics (CFD). Heat transfer models obtained on the base of CFD simulations are implemented in the Phase-change Effective Convectivity Model (PECM) for simulation of reactor-scale accident progression heat transfer in real 3D geometry of the BWR lower plenum. We found that the influence of the low Pr number on the thermal loads in a big melt pool becomes more significant at later time, than rapid acceleration of the creep in the vessel wall. This result suggests that global vessel failure is insensitive to the melt composition in the considered 0.7 m deep melt pool configuration. However, it is not clear yet if the low Pr number effect has an influence on vessel failure mode in the other possible melt pool configurations. (author)

  7. Development of the impression material for the replica of the reactor components in pool

    It is a very difficult and time-consuming work to remove and install the components because of its inherent characteristics and the physical interference with other components in the reactor core. We developed to easily inspect the wear marks or the deformation of the reactor components, for our purpose, a proper impression compound from the commercial material usually called vinylpolysiloxane which dentists are generally using. A proper mixing rate of the additional silica powder, the chemical catalyst and the commercial material was decided through various tests to ensure the good workability, appropriate hardening time as well as taking a good replication of the reactor components. To develop the compound satisfying applicable conditions in the reactor pool, we considered the tool handling time, the water temperature, deformations of the compound during tool handling, and radiation damages of the compound in the reactor core. We had finally developed the impression material for our purpose and successfully accomplished the inspection of the wear marks for a few fuel channels. Also, we have another plan to inspect the deformation of the spider pin of the fuel channel by using an impression material

  8. Online failed fuel identification using delayed neutron detector signals in pool type reactors

    In todays world, nuclear reactors are at the forefront of modern day innovation and reactor designs are increasingly incorporating cutting edge technology. It is of utmost importance to detect failure or defects in any part of a nuclear reactor for healthy operation of reactor as well as the safety aspects of the environment. Despite careful fabrication and manufacturing of fuel pins, there is a chance of clad failure. After fuel pin clad rupture takes place, it allows fission products to enter in to sodium pool. There are some potential consequences due to this such as Total Instantaneous Blockage (TIB) of coolant and primary component contamination. At present, the failed fuel detection techniques such as cover gas monitoring (alarming the operator), delayed neutron detection (DND-automatic trip) and standalone failed fuel localization module (FFLM) are exercised in various reactors. The first technique is a quantitative measurement of increase in the cover gas activity background whereas DND system causes automatic trip on detecting certain level of activity during clad wet rupture. FFLM is subsequently used to identify the failed fuel subassembly. The later although accurate, but mainly suffers from downtime and reduction in power during identification process. The proposed scheme, reported in this paper, reduces the operation of FFLM by predicting the faulty sector and therefore reducing reactor down time and thermal shocks. The neutron evolution pattern gets modulated because fission products are the delay neutron precursors. When they travel along with coolant to Intermediate heat Exchangers, experienced three effects i.e. delay; decay and dilution which make the neutron pulse frequency vary depending on the location of failed fuel sub assembly. This paper discusses the method that is followed to study the frequency domain properties, so that it is possible to detect exact fuel subassembly failure online, before the reactor automatically trips. (author)

  9. modeling of a total loss pool water accident in mtr reactor

    in this study , it is intended to analyze early phases of a protected loss of coolant accident (LOCA)for MTR reactor. and to show the applicability of the presented model to the other similar types of research reactors. the transient situation since the time when coolant is beginning to be lost throughout one or more of the main coolant pipes which were supposed to be broken guillotine-like to the time when the core is totally uncovered is investigated. the modeling of the problem was separated into two phases; in the first phase when the water level of the pool is being decreased in a pre-estimated time -dependent way calculated by using modified Bernoulli equation, the conservation equation are solved by using shooting method. the later phase, when water level reaches the top level of fuel plates and begins to decrease until bottom of the core, and the fuel plates are being cooled by air.

  10. Adaptations to squid-style high-speed swimming in Jurassic belemnitids.

    Klug, Christian; Schweigert, Günter; Fuchs, Dirk; Kruta, Isabelle; Tischlinger, Helmut

    2016-01-01

    Although the calcitic hard parts of belemnites (extinct Coleoidea) are very abundant fossils, their soft parts are hardly known and their mode of life is debated. New fossils of the Jurassic belemnitid Acanthoteuthis provided supplementary anatomical data on the fins, nuchal cartilage, collar complex, statoliths, hyponome and radula. These data yielded evidence of their pelagic habitat, their nektonic habit and high swimming velocities. The new morphological characters were included in a cladistic analysis, which confirms the position of the Belemnitida in the stem of Decabrachia (Decapodiformes). PMID:26740564

  11. Decay heat removal in pool type fast reactor using passive systems

    Highlights: ► Three dimensional thermal hydraulic analysis of decay heat system in a fast reactor model predictions compared with experimental results from PHENIX. ► Calculations confirm adequacy of natural convection in decay heat removal. ► Inter-wrapper flow found to reduce peak temperatures by 50 K in the blanket zone. - Abstract: Post shutdown decay heat removal in a fast reactor is one of the most important safety functions which must be accomplished with a very high reliability. To achieve high reliability, the fast breeder reactor design has emphasized on passive or near passive decay heat removal systems utilizing the natural convection in the heat removal path. A typical passive decay heat removal system used in recent designs of fast breeder reactors consists of a sodium to sodium heat exchanger and sodium to air heat exchanger which together remove heat directly from the hot pool to the final heat sink, which is air. Since these are safety systems, it is necessary to confirm the design with detailed numerical analysis. The numerical studies include pool hydraulics, natural convection phenomena in closed loops, flow through narrow gaps between SA, multi-scale modeling, etc. Toward understanding the evolution of thermal hydraulic parameters during natural convection decay heat removal, a three-dimensional CFD model for the primary system coupled with an appropriate one-dimensional model for the secondary system is proposed. The model has been validated against the results of natural convection test conducted in PHENIX reactor. Adopting the model for the Indian PFBR, six different decay heat removal cases have been studied which bring out the effect of safety grade decay heat removal system (SGDHRS) capacity, secondary sodium inventory and inter-wrapper flow heat transfer on the subassembly outlet temperatures that are important for safety evaluation of the reactor. From the results, it is concluded that the delay in initiation of SGDHRS, replacement

  12. Criticality calculations for a spent fuel storage pool for a BWR type reactor

    In this work, the methodology for the calculation of the constant of effective multiplication for the arrangement of spent fuel assemblies in the pool of a BWR type reactor is shown. Calculations were done for the pool of spent fuel specified in FSAR and for the assemblies that is thought a conservative composition of high enrichment and without Gadolinium, giving credit to the stainless steel boxes of the frames that keep the assemblies. To carry out this simulation, RECORD and MIXQUIC codes were used. With record code, macroscopic cross sections, two energy groups, for the characteristics of the thought assemblies were obtained. Cross sections, as well as the dimensions of the frames that keep the fuel assemblies were used as input data for MIXQUIC code. With this code, criticality calculations in two dimensions were done, supposing that there is not leak of neutrons along the axial of the main line. Additional calculations, supposing changes in the temperature, distance among fuel assemblies and the thickness of the stainless steel box of the frame were done. The obtained results, including the effect in tolerances due to temperature, weight and thickness, show that the arrangement in the pool, when frames are fully charged, is subcritical by less than 5% in δK. (Author)

  13. Thermal hydraulics in the hot pool of Fast Breeder Test Reactor

    Sodium cooled Fast Breeder Test Reactor (FBTR) of 40 MWt/13 MWe capacity is in operation at Kalpakkam, near Chennai. Presently it is operating with a core of 10.5 MWt. Knowledge of temperatures and flow pattern in the hot pool of FBTR is essential to assess the thermal stresses in the hot pool. While theoretical analysis of the hot pool has been conducted by a three-dimensional code to access the temperature profile, it involves tuning due to complex geometry, thermal stresses and vibration. With this in view, an experimental model was fabricated in 1/4 scale using acrylic material and tests were conducted in water. Initially hydraulic studies were conducted with ambient water maintaining Froude number similarity. After that thermal studies were conducted using hot and cold water maintaining Richardson similitude. In both cases Euler similarity was also maintained. Studies were conducted simulating both low and full power operating conditions. This paper discusses the model simulation, similarity criteria, the various thermal hydraulic studies that were carried out, the results obtained and the comparison with the prototype measurements.

  14. Current activities of chemical applications of Tsing Hua Open-pool Reactor

    Tsing Hua Open-pool Reactor (THOR) is a swiming pool type research reactor operated and maintained by the University. The functions of THOR are two folds, i.e. (1) teaching and training of nuclear scientists and engineers, and (2) promotion of peaceful uses of atomic energy in Taiwan. Thus, besides the educational program THOR has been offering neutron irradiation service on regular schedule (30 hrs. per week full power operation at 1 MW with neutron flux of ca. 2 x 1012 n cm-2 sec.-1 since 1963). Among many other projects chemical application of THOR has been one of the important program implimented in early days. Following two projects have been set up with rather limited budget: (1) Production and supply of short-lived radioisotopes (both general purpose and medical use) for domestic use. (2) Application of neutron activation analysis in the fields of environmental, geological, biological and material science. It turned out that quite fruitful results have been obtained. It is the purpose of this paper to describe in detail some of the characteristic aspects on the utilization of THOR in the field of chemical application. (author)

  15. Toward a conceptual understanding of acute cultural adaptation: A preliminary examination of ACA in female swimming

    Ryba, Tatiana; Haapanen, Saara; Mosek, Shwiko; Ng, Kwok

    2012-01-01

    This paper considers a novel approach to researching adaptation in transnational athletes. The first part introduces a conceptualisation of acute cultural adaptation (ACA), which extends the current literature in sport psychology by offering original insights into mechanisms underpinning adaptive...... psychological needs. The second part of the paper engages the conceptualisation of ACA to make sense of the adaptive processes as experienced by female swimmers from Finland during their training camp in Australia. The study’s findings highlight relatedness as a discursive cultural space, offering a starting...... point for examining the role of culture in psychological functions during short-term relocation....

  16. Adaptive Controller Design for Continuous Stirred Tank Reactor

    Prabhu, K; V. Murali Bhaskaran

    2014-01-01

    Continues Stirred Tank Reactor (CSTR) is an important issue in chemical process and a wide range of research in the area of chemical engineering. Temperature Control of CSTR has been an issue in the chemical control engineering since it has highly non-linear complex equations. This study presents problem of temperature control of CSTR with the adaptive Controller. The Simulation is done in MATLAB and result shows that adaptive controller is an efficient controller for temperature control of C...

  17. Pressure drop calculation in a fuel element of a pool type reactor

    Even with the advances of hardware in computer sciences, sometimes it is necessary to simplify the simulation in order to optimize the results given the same calculation runtime. The object of this study is a thermodynamic analysis of the core of a pool type research reactor, focusing on natural circulation. Due to the high geometrical complexity of the core, the scale transfer process becomes an essential step to the thermodynamic study of the reactor. This process takes place by determining the effective equivalent properties obtained from a detailed simulation of the core and transferring them to a porous medium having a coarse mesh while preserving the overall characteristics. In this way, it will be able to obtain the quadratic resistance coefficient KQ by calculating the pressure drop inside the fuel element. To observe in detail the behavior of this flow, longitudinal and transversal cross sections will be made in different points, thereby observing the velocity and pressure distributions. The analysis will provide detailed data on the fluid flow between the fuel plates enabling the observation of possible critical points or undesired behavior. The whole analysis was made by using the commercial code ANSYS CFX ver. 12.1. This is study will provide data, as a first step to enable future simulations which will consider the entire reactor. (author)

  18. COMMIX-1C code estimation for the pool dynamics of Istanbul Technical University TRIGA MARK-II reactor

    In this study, the COMMIX-1C code is used to investigate the pool dynamics of Istanbul Technical University (ITU)TRIGA MARK-II reactor by simulating the velocity, pressure and temperature distributions in the reactor pool as a function of core design parameters and pool configuration. COMMIX-1C is multi-purpose, three-dimensional. transient, single-phase, thermal-hydraulics computer code. For the mass, momentum and energy equations, it uses a porous-medium formulation, a finite-volume algorithm, a flow modulated skew-upwind discretization scheme to reduce numerical diffusion and k-ε two-equation turbulence model. Its implementation for the particular system requires geometric and physical modelling decisions. ITU TRIGA MARK-II reactor pool is considered partly as continuum and partly as porous medium. All the major pool components are explicitly modelled in the simulation. Shape of the pool structure and computational cells are accounted for using the concept of directional surface permeability, volume porosity, distributed resistance, and distributed heat source or sink. The results are compared to the results of the computer codes TRISTAN, TRIGATH and TRIGATH-R

  19. Whole core analysis of an open pool research reactor under the most severe loss of coolant accident conditions

    In the present work the accident in which either the outlet or the inlet coolant pipe connected to the bottom of the reactor tank in an open pool research reactor is completely ruptured has been analyzed. The 3-D transient computer code ThEAP-I developed at Democritus NRC has been utilized and applied to the 5 MW Greek Research Reactor (GRR-1). The results show that a partial melting of the reactor core is possible for the GRR-1, the amount of melting being roughly and conservatively estimated to be of the order of 20%. (author)

  20. Application of stable adaptive schemes to nuclear reactor systems, (1)

    Parameter identification and adaptive control schemes are presented for a point reactor with internal feedbacks which lead to the nonlinearity of the overall system. Both are shown stable with new representation of the system, which corresponds to the nonminimal system representation, in the vein of the Model Reference Adaptive System (MRAS) via the Lyapunov's method. For the sake of the parameter identification, model parameters can be adjusted adaptively as soon as measurements start, while plant parameters can also adaptively be compensated through control input to reduce the output error between the model and the plant for the case of the adaptive control. In the case of the adaptive control, control schemes are presented for two cases, the case of the unknown decay constant of the delayed neutron and the case of the known constant. The adaptive control scheme for the latter case is shown extremely simpler than that for the former. Furthermore, when plant parameters vary slowly with time, computer simulations show that the proposed adaptive control scheme works satisfactorily enough to stabilize an unstable reactor and that it does even in the noise with small variance. (auth.)

  1. Characterization of radioactive contaminants and water treatment trials for the Taiwan Research Reactor's spent fuel pool

    Highlights: ► Deal with a practical radioactive contamination in Taiwan Research Reactor spent fuel pool water. ► Identify the properties of radioactive contaminants and performance test for water treatment materials. ► The radioactive solids were primary attributed by ruptured spent fuels, spent resins, and metal debris. ► The radioactive ions were major composed by uranium and fission products. ► Diatomite-based ceramic depth filter can simultaneously removal radioactive solids and ions. - Abstract: There were approximately 926 m3 of water contaminated by fission products and actinides in the Taiwan Research Reactor's spent fuel pool (TRR SFP). The solid and ionic contaminants were thoroughly characterized using radiochemical analyses, scanning electron microscopy equipped with an energy dispersive spectrometer (SEM-EDS), and inductively coupled plasma optical emission spectrometry (ICP-OES) in this study. The sludge was made up of agglomerates contaminated by spent fuel particles. Suspended solids from spent ion-exchange resins interfered with the clarity of the water. In addition, the ionic radionuclides such as 137Cs, 90Sr, U, and α-emitters, present in the water were measured. Various filters and cation-exchange resins were employed for water treatment trials, and the results indicated that the solid and ionic contaminants could be effectively removed through the use of <0.9 μm filters and cation exchange resins, respectively. Interestingly, the removal of U was obviously efficient by cation exchange resin, and the ceramic depth filter composed of diatomite exhibited the properties of both filtration and adsorption. It was found that the ceramic depth filter could adsorb β-emitters, α-emitters, and uranium ions. The diatomite-based ceramic depth filter was able to simultaneously eliminate particles and adsorb ionic radionuclides from water.

  2. Transient analysis of dissolution of a reactor bottom head into a melt pool

    The dissolution of the bottom head of a heavy-water reactor into a pool of molten fuel under severe accident conditions is investigated using a distributed-parameter model. The main objectives are to determine the rate of dissolution-front propagation and to estimate the extent to which the bottom head is thinned owing to dissolution. The model consists mainly of partitioning the bottom head into a number of rings and analyzing the transient dissolution of each ring with a localized lumped-parameter model. For each of the rings, the dissolution is modeled using a mass transfer coefficient, the temperature distribution is considered to be one dimensional and quasisteady and the heat flux across the melt-bottom head interface is modeled using a heat transfer coefficient. The distribution of the heat transfer coefficients is considered to be quasi-steady and is based on the heat transfer calculation results obtained using the ACCORD code. The model thus takes into account both the variation of heat fluxes over the melt pool-bottom head interface and the variations of interface mass transfer with time and with position along the interface. The basic equations and their solution method for the distributed-parameter model are described. Comparisons of calculation results with those obtained previously using the overall lumped-parameter model are presented

  3. E-SCAPE: A scale facility for liquid-metal, pool-type reactor thermal hydraulic investigations

    Highlights: • The E-SCAPE facility is a thermal hydraulic scale model of the MYRRHA fast reactor. • The focus is on mixing and stratification in liquid-metal pool-type reactors. • Forced convection, natural convection and the transition are investigated. • Extensive instrumentation allows validation of computational models. • System thermal hydraulic and CFD models have been used for facility design. - Abstract: MYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Applications) is a flexible fast-spectrum research reactor under design at SCK·CEN. MYRRHA is a pool-type reactor with lead bismuth eutectic (LBE) as primary coolant. The proper understanding of the thermal hydraulic phenomena occurring in the reactor pool is an important issue in the design and licensing of the MYRRHA system and liquid-metal cooled reactors by extension. Model experiments are necessary for understanding the physics, for validating experimental tools and to qualify the design for the licensing. The E-SCAPE (European SCAled Pool Experiment) facility at SCK·CEN is a thermal hydraulic 1/6-scale model of the MYRRHA reactor, with an electrical core simulator, cooled by LBE. It provides experimental feedback to the designers on the forced and natural circulation flow patterns. Moreover, it enables to validate the computational methods for their use with LBE. The paper will elaborate on the design of the E-SCAPE facility and its main parameters. Also the experimental matrix and the pre-test analysis using computational fluid dynamics (CFD) and system thermal hydraulics codes will be described

  4. E-SCAPE: A scale facility for liquid-metal, pool-type reactor thermal hydraulic investigations

    Van Tichelen, Katrien, E-mail: kvtichel@sckcen.be [SCK-CEN, Boeretang 200, 2400 Mol (Belgium); Mirelli, Fabio, E-mail: fmirelli@sckcen.be [SCK-CEN, Boeretang 200, 2400 Mol (Belgium); Greco, Matteo, E-mail: mgreco@sckcen.be [SCK-CEN, Boeretang 200, 2400 Mol (Belgium); Viviani, Giorgia, E-mail: giorgiaviviani@gmail.com [University of Pisa, Lungarno Pacinotti 43, 56126 Pisa (Italy)

    2015-08-15

    Highlights: • The E-SCAPE facility is a thermal hydraulic scale model of the MYRRHA fast reactor. • The focus is on mixing and stratification in liquid-metal pool-type reactors. • Forced convection, natural convection and the transition are investigated. • Extensive instrumentation allows validation of computational models. • System thermal hydraulic and CFD models have been used for facility design. - Abstract: MYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Applications) is a flexible fast-spectrum research reactor under design at SCK·CEN. MYRRHA is a pool-type reactor with lead bismuth eutectic (LBE) as primary coolant. The proper understanding of the thermal hydraulic phenomena occurring in the reactor pool is an important issue in the design and licensing of the MYRRHA system and liquid-metal cooled reactors by extension. Model experiments are necessary for understanding the physics, for validating experimental tools and to qualify the design for the licensing. The E-SCAPE (European SCAled Pool Experiment) facility at SCK·CEN is a thermal hydraulic 1/6-scale model of the MYRRHA reactor, with an electrical core simulator, cooled by LBE. It provides experimental feedback to the designers on the forced and natural circulation flow patterns. Moreover, it enables to validate the computational methods for their use with LBE. The paper will elaborate on the design of the E-SCAPE facility and its main parameters. Also the experimental matrix and the pre-test analysis using computational fluid dynamics (CFD) and system thermal hydraulics codes will be described.

  5. Weekly self-scheduling, forward contracting, and pool involvement for an electricity producer: an adaptive robust optimization approach

    Ricardo M. Lima; Novais, Augusto Q.; Conejo, Antonio J.

    2015-01-01

    his paper addresses the optimization under uncertainty of the self-scheduling, forward contracting, and pool involvement of an electricity producer operating a mixed power generation station, which combines thermal, hydro and wind sources, and uses a two stage adaptive robust optimization approach. In this problem the wind power production and the electricity pool price are considered to be uncertain, and are described by uncertainty convex sets. To solve this problem, two variants of a const...

  6. Evaluation of pool swell velocity during large break loss of coolant accident in boiling water reactor Mark III containment design

    Yan Jin, E-mail: jinyan10@gmail.co [GE-Hitachi Nuclear Energy, 3901 Castle Hayne Road, Wilmington, M/L-30, NC 28402 (United States); Bolger, Francis [GE-Hitachi Nuclear Energy, 3901 Castle Hayne Road, Wilmington, M/L-30, NC 28402 (United States)

    2010-07-15

    In boiling water reactor (BWR) design, safety scenarios such as main steam line break need to be evaluated. After the main steam line break, the steam will fill the upper dry well of the containment. It will then enter the vertical vent and eventually flow into the suppression pool via horizontal vents. The steam will create large bubbles in the suppression pool and cause the pool to swell. The impact of the pool swell on the equipment inside the pool and containment structure needed to be evaluated for licensing. GE has conducted a series of one-third scale three-vent air tests in supporting the horizontal vent pressure suppression system used in Mark III containment design for General Electric BWR plants. During the test, the air-water interface locations were tracked by conductivity probes. The pressure was measured at many locations inside the test rig as well. The purpose of the test was to provide a basis for the pool swell load definition for the Mark III containment. In this paper, a transient three-dimensional CFD model to simulate the one-third scale Mark III suppression pool swell process is illustrated. The Volume of Fluid (VOF) multiphase model is used to explicitly track the interface between the water liquid and the air. The CFD results such as flow velocity, pressure, interface locations are compared to the data from the test. Through comparisons, a technical approach to numerically model the pool swell phenomenon is established and benchmarked.

  7. Evaluation of pool swell velocity during large break loss of coolant accident in boiling water reactor Mark III containment design

    In boiling water reactor (BWR) design, safety scenarios such as main steam line break need to be evaluated. After the main steam line break, the steam will fill the upper dry well of the containment. It will then enter the vertical vent and eventually flow into the suppression pool via horizontal vents. The steam will create large bubbles in the suppression pool and cause the pool to swell. The impact of the pool swell on the equipment inside the pool and containment structure needed to be evaluated for licensing. GE has conducted a series of one-third scale three-vent air tests in supporting the horizontal vent pressure suppression system used in Mark III containment design for General Electric BWR plants. During the test, the air-water interface locations were tracked by conductivity probes. The pressure was measured at many locations inside the test rig as well. The purpose of the test was to provide a basis for the pool swell load definition for the Mark III containment. In this paper, a transient three-dimensional CFD model to simulate the one-third scale Mark III suppression pool swell process is illustrated. The Volume of Fluid (VOF) multiphase model is used to explicitly track the interface between the water liquid and the air. The CFD results such as flow velocity, pressure, interface locations are compared to the data from the test. Through comparisons, a technical approach to numerically model the pool swell phenomenon is established and benchmarked.

  8. Do-it-yourself solar installations. Theory and practice of solar collector technology. Water heating, swimming-pool heating and space heating. 8. ed. Solaranlagen im Selbstbau. Theorie und Praxis der Sonnenkollektortechnik. Warmwasserbereitung, Schwimmbad- und Raumheizung

    Lorenz-Ladener, C.; Ladener, H.

    1989-01-01

    Elements of solar technology such as collectors, storage facilities and heat transport facilities are used to show how solar installations are planned, measured and built nowadays. Proven do-it-yourself systems for water-heating, swimming-pools and space heating are described and examples of completed DIY systems are presented. Not only the DIY enthusiast but also the purchaser of ready-made solar installations can see the state of the technology and get concrete help in reaching decisions from reading about experiences with the performance of solar installations and details of costs and economic viability. (orig.).

  9. Geneva 24 Hours Swim

    2003-01-01

    The 18th edition of the Geneva 24 hours swim competition will take place at the Vernets Swimming Pool on the 4th and 5th of October. More information and the results of previous years are given at: http://www.carouge-natation.com/24_heures/home_24_heures.htm Last year, CERN obtained first position in the inter-company category with a total of 152.3 kms swam by 45 participants. We are counting on your support to repeat this excellent performance this year. For those who would like to train, the Livron swimming pool in Meyrin is open as from Monday the 8th September. For further information please do not hesitate to contact us. Gino de Bilio and Catherine Delamare

  10. Geneva 24 hours swim

    2003-01-01

    The 18th edition of the Geneva 24 hours swim competition will take place at the Vernets Swimming Pool on the 4th and 5th of October. More information and the results of previous years are given at: http://www.carouge-natation.com/24_heures/home_24_heures.htm Last year, CERN obtained first position in the inter-company category with a total of 152.3 kms swam by 45 participants. We are counting on your support to repeat this excellent performance this year. For those who would like to train, the Livron swimming pool in Meyrin is open as from Monday the 8th September. For further information please do not hesitate to contact us. Gino de Bilio and Catherine Delamare

  11. Development of a fuel failure monitoring method for a pool-type research reactor

    Studies on developing a sensitive monitoring method of possible release of fission products (FP) from a fuel element have been made for a pool-type research reactor. It consists of introducing gas bubbles into reactor coolant water to extract effectively the dissolved fission rare gases, 89Kr and 138Xe, produced somewhere in the core, and counting their respective daughter nuclides, 89Rb and 138Cs with high efficiency. The measurements were done by either method, (I) on a filter paper by sucking the bubbled gas and air covering water of the reactor tank, or (II) in the washing water of bubbled gas sampled into a bottle at the water surface. The followings are the summary of the results obtained. (1) DE increased as much as 30 times or more compared with no gas bubbling. (2) DE largely increased with increasing flow rate of introducing gas. (3) DE increased with increasing depth of the gas exit in the water. (4) DE at the same depth depended on the position of gas exit. It was larger for 'side' position than for 'center', due to the water convection in the tank. (5) DE largely depended on the condition of whether the primary cooling system was operated or not. (6) In Method II, DE depended on the time of standing, and it showed maximum at the theoretically predicted value. (7) The theoretical analysis for the effect of depth suggests that DE should be proportional to the value =(1+D /1033)2-(1+D /1033)5/3=, where D is the depth (in cm). The trend agreed at least partly with the observed data. (8) As a continuous mode experiment, we constructed an automatic fuel monitoring system for routine use by adopting Method II. It is composed of an intermittent sampling of the bubbling gas into bottle at the water surface, washing it with water after definite time of standing, and measuring the nuclides contained in the water. (J.P.N.)

  12. Status of national programmes on fast breeder reactors. Eighteenth annual meeting, Vienna, Austria, 16-19 April 1985

    The Eighteenth Annual Meeting on the Status of National Programmes in Member States of the IAEA on Fast Breeder Reactors had been held in April 1985. The representatives of the Member States and international organizations reported status and activities in the field of fast breeder reactors development and operation. A separate abstract was prepared for each of the 12 presentations of the meeting

  13. The radionuclides of primary coolant in HANARO and the recent activities performed to reduce the radioactivity or reactor pool water

    Kim, Minjin [HANARO Research Reactor Centre, Korea Atomic Energy Research Inst., Taejon (Korea, Republic of)

    1998-10-01

    In HANARO reactor, there have been activities to identify the principal radionuclides and to quantify them under the normal operation. The purposes of such activities were to establish the measure by which we can reduce the radioactivity of the reactor pool water and detect, in early stage, the abnormal symptoms due to the leakage of radioactive materials from the irradiation sample or the damage of the nuclear fuel, etc. The typical radionuclides produced by the activation of reactor coolant are N{sup 16} and Ar{sup 41}. The radionuclides produced by the activation of the core structural material consist of Na{sup 24}, Mn{sup 56}, and W{sup 187}. Of the various radionuclides, governing the radiation level at the pool surface are Na{sup 24}, Ar{sup 41}, Mn{sup 58}, and W{sup 187}. By establishing the hot water layer system on the pool surface, we expected that the radionuclides such as Ar{sup 41} and Mn{sup 56} whose half-life are relatively short could be removed to a certain extent. Since the content of radioactivity of Na{sup 24} occupies about 60% of the total radioactivity, we assumed that the total radiation level would be greatly reduced if we could decrease the radiation level of Na{sup 24}. However the actual radiation level has not been reduced as much as we expected. Therefore, some experiments have been carried out to find the actual causes afterwards. What we learned through the experiments are that any disturbance in reactor pool water layer causes increase of the pool surface radiation level and even if we maintain the hot water layer well, reactor shutdown will be very much likely to happen once the hot water layer is disturbed. (author)

  14. Statistical evaluation of potential damage to the Al(OH){sub 3} layer on nTiO{sub 2} particles in the presence of swimming pool and seawater

    Virkutyte, Jurate [Pegasus Technical Services, Inc (United States); Al-Abed, Souhail R., E-mail: al-abed.souhail@epa.gov [U.S. Environmental Protection Agency, National Risk Management Research Laboratory (United States)

    2012-03-15

    Nanosized TiO{sub 2} particles (nTiO{sub 2}) are usually coated with an Al(OH){sub 3} layer when used in sunscreen to shield against the harmful effects of free radicals that are generated when these particles are exposed to UV radiation. Therefore, it is vital to insure the structural stability of these particles in the environment where the protective layer may be damaged and adverse health and environmental effects can occur. This study utilized X-ray analysis (SEM-EDS) to provide a qualitative and semi-quantitative assessment of the chemical and physical characteristics of Al(OH){sub 3}-coated original and damaged nTiO{sub 2} particles (used in sunscreen lotion formulations) in the presence of both swimming pool and seawater. Also, by utilizing statistical tools, a distribution of Al/Ti (%) on the particle surface was determined and evaluated. It was found that 45 min of treatment with swimming pool and seawater significantly induced the redistribution of Al/Ti (%), which changed the surface characteristics of particles and, therefore, may have induced undesired photo-activity and the consequent formation of free radicals.

  15. The solar heating system of the sport centre 'Guillamo Swimming Pool' in Sierre, Switzerland; Installation solaire thermique. Complexe sportif de la piscine de Guillamo - Rapport final

    NONE

    2008-07-01

    This illustrated report for the Swiss Federal Office of Energy describes the refurbishment and the extension of the sport centre 'Guillamo Swimming Pool' in Sierre, Switzerland. The original building built in 1978 included three swimming pools (two indoor and one small outdoor). In 2005 a three-room fitness centre, a wellness centre and a bar were added to the compound and the old building and technical installations refurbished. At the same time a 591 m{sup 2} solar collector array was added. Unglazed selective solar absorbers were mounted on the 5{sup o} tilted flat roof. They insure at the same time the water tightness of the roof, a feature that lead to a significant cost reduction of the project. Before 2005 the natural gas consumption of the centre was 1.3 to 1.7 GWh/year. After the construction work the consumption was about 1.6 GWh, including a contribution of 0.06 GWh from the solar collectors. This last figure is disappointing. The reasons for this are mainly attributed by the authors to a very poor integration of the solar collectors into the conventional heat generation and distribution system, which do not enable the solar collectors to deliver the heat quantity they should. Changes should be made on the hydraulics of the whole system and on the control algorithms and settings.

  16. Application of stable adaptive schemes to nuclear reactor systems, (3)

    Stable parameter identification and adaptive control schemes are considered for a reactor model embodying two temperature feedbacks-slow and fast. This reactor model is liable to see its feedback coefficients change sign in the course of long periods of operation, resulting in nonlinear oscillations of neutron flux, which cannot be described by a linearized model. This nonlinear system is expressed in terms of memoryless nonlinear elements in the feedback loop of a linear system, with the aid of linear and nonlinear transformations, and the nonlinear elements are here treated without being linearized. A new system representation is introduced, using which, stable parameter identification and adaptive control schemes are developed in the pattern of the Model Reference Adaptive System (MRAS) with use made of the Lyapunov method. Both schemes are shown to be stable, and furthermore globally stable if the input has frequencies sufficiently varied to permit all the excited modes to be considered linearly independent. It is thus shown that the estimated parameters converge to the true values for the parameter identification, and that, for the adaptive control, the output error between the plant and the model tends toward zero. (author)

  17. Reduced scale simulations of boiling water reactor pool swell: some limitations to the scaling laws

    Several potential sources of misscaling in reduced scale experimental tests have been systematically investigated. Increases in the enthalpy in-flux during pool swell increase resultant uploads; slight boundary flexibility due to small air bubbles attached to the pool walls or true fluid structure interaction can increase peak pool boundary loads; the presence of water vapor in the wetwell airspace can either increase or decrease pool swell uploads, depending on the vapor fraction initially present. 14 refs

  18. Application of stable adaptive schemes to nuclear reactor systems, (4)

    In undertaking parameter identification and adaptive control of a thermo-hydraulic system representing the core channels of nuclear reactor plants, if the flow velocity in a channel can be assumed to be the input and the outlet temperature the output, the system considered can be classed as bilinear on account of the multiplication terms for the temperature and flow velocity contained in the equations representing the same system. A new representation for this bilinear system is proposed, and the adaptive schemes for both parameter identification and control are developed in the pattern of the Model Reference Adaptive System with use made of the Lyapunov method. Both schemes are shown to be stable, and to further be globally stable if the inputs possess frequencies sufficiently varied. Some successful parameter identification experiments based on the proposed method are covered, which were performed on a test section representing a simplified channel in which the input-flow rate is varied in binary pattern. (author)

  19. Exercise-training intervention studies in competitive swimming.

    Aspenes, Stian Thoresen; Karlsen, Trine

    2012-06-01

    Competitive swimming has a long history and is currently one of the largest Olympic sports, with 16 pool events. Several aspects separate swimming from most other sports such as (i) the prone position; (ii) simultaneous use of arms and legs for propulsion; (iii) water immersion (i.e. hydrostatic pressure on thorax and controlled respiration); (iv) propulsive forces that are applied against a fluctuant element; and (v) minimal influence of equipment on performance. Competitive swimmers are suggested to have specific anthropometrical features compared with other athletes, but are nevertheless dependent on physiological adaptations to enhance their performance. Swimmers thus engage in large volumes of training in the pool and on dry land. Strength training of various forms is widely used, and the energetic systems are addressed by aerobic and anaerobic swimming training. The aim of the current review was to report results from controlled exercise training trials within competitive swimming. From a structured literature search we found 17 controlled intervention studies that covered strength or resistance training, assisted sprint swimming, arms-only training, leg-kick training, respiratory muscle training, training the energy delivery systems and combined interventions across the aforementioned categories. Nine of the included studies were randomized controlled trials. Among the included studies we found indications that heavy strength training on dry land (one to five repetitions maximum with pull-downs for three sets with maximal effort in the concentric phase) or sprint swimming with resistance towards propulsion (maximal pushing with the arms against fixed points or pulling a perforated bowl) may be efficient for enhanced performance, and may also possibly have positive effects on stroke mechanics. The largest effect size (ES) on swimming performance was found in 50 m freestyle after a dry-land strength training regimen of maximum six repetitions across three

  20. Migration of activation products in discharges pool in T.H.O.R. nuclear research reactor site boundary

    Due to material degradation in tubing, the heat exchanger for the primary coolant of the 1 MW Tsing Hua Open-pool Reactor(THOR) has minor leakage to the secondary cooling system since 1970. In the past twenty years, trace amount of Co-58, 60, Cr-51, Cs-137, Mn-54, Sc-46, and Zn-65 have been leaked through the cooling system, accumulated and trapped eventually in the discharge pool right in front of the THOR facility. The distribution of these activation products in mud at different depths and various locations in the pool was measured with standard procedures of radioactive soil sampling and counting techniques. Concentration of activation products, with no more than 40 kBq/kg. dry at the hottest spot, was contour-mapped to reveal the migration of these trace level radioactive products in a period of 20 years

  1. Performance analyses of the pool-top radiation level reduction systems at the ETRR-2 research reactor

    An analysis of the performance of the hot water layer system, HWLS, and the interconnection system, IS, at the ETRR-2 research reactor is presented. The behavior of the HWLS during the formation period of the hot water layer has been studied and is presented together with the pool-top measured radiation level associated with that behavior. Two different designs of the HWLS have been experimentally evaluated. For these two different designs, the radiation level at the ETRR-2 pool-top were characterized and discussed. The effect of adding a water purification system to the HWLS is demonstrated as well as the effect of the IS on the pool-top radiation level considering different operational conditions of the HWLS. The study shows the importance of these systems from the radiological protection point of view. (orig.)

  2. Three-dimensional fluid-structure interaction dynamics of a pool-reactor in-tank component. [LMFBR

    Kulak, R.F.

    1979-01-01

    The safety evaluation of reactor-components often involves the analysis of various types of fluid/structural components interacting in three-dimensional space. For example, in the design of a pool-type reactor several vital in-tank components such as the primary pumps and the intermediate heat exchangers are contained within the primary tank. Typically, these components are suspended from the deck structure and largely submersed in the sodium pool. Because of this positioning these components are vulnerable to structural damage due to pressure wave propagation in the tank during a CDA. In order to assess the structural integrity of these components it is necessary to perform a dynamic analysis in three-dimensional space which accounts for the fluid-structure coupling. A model is developed which has many of the salient features of this fluid-structural component system.

  3. Ageing Management and Preventice Measures for Reactor Pool Liners, Beam Tubes and Spent Fuel Storage Tank at the Dalat Research Reactor

    Dien, Nguyen Nhi; Dien, Nguyen Minh; Su, Trang Cao [Nuclear Research Institute, Henoi (Viet Nam)

    2013-07-01

    The 500-kw Dalat Nuclear Research Reactor (DNRR) was reconstructed from the original 250-kW TRIGA Mark II as named of VN-001. In the framework of the reconstruction project during the 1982-1984 period, some structures of the TRIGA reactor constructed in the early sixties, such as the aluminum tank, graphite reflector, thermal column, four horizontal beam tubes, etc. have been remained. It means, such components are more than 50 years old and are facing with ageing issues. The structural materials of the pool liner and other components of TRIGA were made of aluminum alloy 6061 and aluminum cladding fuel assemblies. Some other parts, such as reactor core, irradiation rotary rack around the core, vertical irradiation facilities, etc. were replaced by the former Soviet Union's design with structural materials of aluminum alloy CAV-1. The reactor core has been loaded with HEU VVR-M2 fuel assemblies of 36% enrichment alloy CAV-1. The reactor core has been loaded with HEU VVR-M2 fuel assemblies of U-Al alloy 36% and of UO{sub 2} 19.75% enrichment used aluminum as fuel cladding. For ageing management and preventive measures of corrosion, an underwater high-resolution video camera system had been designed for visual inspections. A home-made cleaning system was also designed for cleaning the pool and other components. Water chemistry of the reactor pool and spent fuel storage was monitored regularly. In September-November 2011, all four horizontal channels were cleaned inside and visual inspection was done using special camera system. It was the first time from 1963 such activity could be done. Based on results obtained we could convince that inside all horizontal channels are in good condition and leakage could not be occurred. All 106 HEU spent fuel assemblies stored in the spent fuel pool in good condition. The visual inspection was done using under water camera too. The results obtained show that the surface of all HEU SFA is good and leakage was not occurred. The

  4. Simulation of the gamma dose rate in a loss of pool water accident of the second Egyptian research reactor ET-RR-2

    The second Egyptian research reactor ET-RR-2, is a pool type reactor. A sudden loss of pool water would leave the core region uncovered. The reactor core is surrounded by chimney chambers with water isolated from the pool water. This accident would lead to significant external doses. A model is developed and used to calculate the dose rates for key access-areas and traffic plans from indirect line of sight of the core which have a maximum dose rate. The model developed uses the discrete ordinate method as implemented in the code DOT3.5. (orig.)

  5. Computational simulation of the natural circulation occurring in an experimental test section of a pool type research reactor

    The present work presents a computational simulation of the natural circulation phenomenon developing in an experimental test section of a pool type research reactor. The test section has been designed using a reduced scale in height 1:4.7 in relation to a pool type 30 MW research reactor prototype. It comprises a cylindrical vessel, which is opened to atmosphere, and representing the reactor pool; a natural circulation pipe, a lower plenum, and a heater containing electrical resistors in rectangular plate format, which represents the fuel elements, with a chimney positioned on the top of the resistor assembly. In the computational simulation, it was used a commercial CFD software, without any turbulence model. Besides, in the presence of the natural circulation, a laminar flow has been assumed and the equations of the mass conservation, momentum and energy were solved by the finite element method. In addition, the results of the simulation are presented in terms of velocities and temperatures differences, respectively: at inlet and outlet of the heater and of the natural circulation pipe. (author)

  6. Computational simulation of the natural circulation occurring in an experimental test section of a pool type research reactor

    Nascimento, Francisco R.T. do; Lima Junior, Carlos A.S.; Oliveira, Andre F.S. de; Affonso, Renato R.W.; Faccini, Jose L.H.; Moreira, Maria L., E-mail: rogerio.tdn@gmail.com, E-mail: souzalima_ca@ien.gov.br, E-mail: oliveira.afelipe@gmail.com, E-mail: raoniwa@yahoo.com.br, E-mail: faccini@ien.gov.br, E-mail: malu@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    The present work presents a computational simulation of the natural circulation phenomenon developing in an experimental test section of a pool type research reactor. The test section has been designed using a reduced scale in height 1:4.7 in relation to a pool type 30 MW research reactor prototype. It comprises a cylindrical vessel, which is opened to atmosphere, and representing the reactor pool; a natural circulation pipe, a lower plenum, and a heater containing electrical resistors in rectangular plate format, which represents the fuel elements, with a chimney positioned on the top of the resistor assembly. In the computational simulation, it was used a commercial CFD software, without any turbulence model. Besides, in the presence of the natural circulation, a laminar flow has been assumed and the equations of the mass conservation, momentum and energy were solved by the finite element method. In addition, the results of the simulation are presented in terms of velocities and temperatures differences, respectively: at inlet and outlet of the heater and of the natural circulation pipe. (author)

  7. Progressive Increase in Disinfection Byproducts and Mutagenicity from Source to Tap to Swimming Pool and Spa Water: Impact of Human Inputs.

    Daiber, Eric J; DeMarini, David M; Ravuri, Sridevi A; Liberatore, Hannah K; Cuthbertson, Amy A; Thompson-Klemish, Alexis; Byer, Jonathan D; Schmid, Judith E; Afifi, Mehrnaz Z; Blatchley, Ernest R; Richardson, Susan D

    2016-07-01

    Pools and spas are enjoyed throughout the world for exercise and relaxation. However, there are no previous studies on mutagenicity of disinfected spa (hot tub) waters or comprehensive identification of disinfection byproducts (DBPs) formed in spas. Using 28 water samples from seven sites, we report the first integrated mutagenicity and comprehensive analytical chemistry of spas treated with chlorine, bromine, or ozone, along with pools treated with these same disinfectants. Gas chromatography (GC) with high-resolution mass spectrometry, membrane-introduction mass spectrometry, and GC-electron capture detection were used to comprehensively identify and quantify DBPs and other contaminants. Mutagenicity was assessed by the Salmonella mutagenicity assay. More than 100 DBPs were identified, including a new class of DBPs, bromoimidazoles. Organic extracts of brominated pool/spa waters were 1.8× more mutagenic than chlorinated ones; spa waters were 1.7× more mutagenic than pools. Pool and spa samples were 2.4 and 4.1× more mutagenic, respectively, than corresponding tap waters. The concentration of the sum of 21 DBPs measured quantitatively increased from finished to tap to pool to spa; and mutagenic potency increased from finished/tap to pools to spas. Mutagenic potencies of samples from a chlorinated site correlated best with brominated haloacetic acid concentrations (Br-HAAs) (r = 0.98) and nitrogen-containing DBPs (N-DBPs) (r = 0.97) and the least with Br-trihalomethanes (r = 0.29) and Br-N-DBPs (r = 0.04). The mutagenic potencies of samples from a brominated site correlated best (r = 0.82) with the concentrations of the nine HAAs, Br-HAAs, and Br-DBPs. Human use increased significantly the DBP concentrations and mutagenic potencies for most pools and spas. These data provide evidence that human precursors can increase mutagenic potencies of pools and spas and that this increase is associated with increased DBP concentrations. PMID:27124361

  8. Fractionated BNCT for locally recurrent head and neck cancer: Experience from a phase I/II clinical trial at Tsing Hua Open-Pool Reactor

    To introduce our experience of treating locally and regionally recurrent head and neck cancer patients with BNCT at Tsing Hua Open-Pool Reactor in Taiwan, 12 patients (M/F=10/2, median age 55.5 Y/O) were enrolled and 11 received two fractions of treatment. Fractionated BNCT at 30-day interval with adaptive planning according to changed T/N ratios was feasible, effective and safe for selected recurrent head and neck cancer in this trial. - Highlights: • We treated 12 patients with recurrent Head and Neck (H and N) cancer after radical surgery and radiotherapy since 2010. • Four complete response (CR) and 3 partial response (PR) were found. Total response rate was 58%. • Two patients had local control longer than one year. • No grade 4 or higher toxicity was noted for both acute and chronic effects

  9. A new impulse in the development of nuclear pool-type reactors for underground heating plant: Designing, running background and possible perspectives

    This paper considers the concept of energy supply with using ultimately safe pool-type integral nuclear reactors. Safety and reliability of these reactors has already been demonstrated to the public by the long-term operation of this type various research reactors. The reactor and power plant design features, new approach to the nuclear safety, the nuclear upgrading of existing energy system in a small Russian town are considered in the paper

  10. Contaminación del aire interior y del agua de baño en piscinas cubiertas de Guipúzcoa Indoor air and bathing water pollution in indoor swimming pools in Guipúzcoa (Spain

    Loreto Santa Marina

    2009-04-01

    Full Text Available Objetivo: Describir los niveles de contaminantes presentes en las piscinas cubiertas de Guipúzcoa, tanto en el agua de baño como en el aire, y estudiar la relación entre estos contaminantes y otras variables relacionadas con los sistemas de ventilación y el uso de las instalaciones. Métodos: De las 35 piscinas cubiertas registradas en Guipúzcoa se estudiaron las 20 más utilizadas por nadadores. Cada instalación se muestreó 2 días no consecutivos y se midieron los niveles de cloro libre y combinado y trihalometanos en el agua, así como los de cloro total y cloroformo en el aire. Como indicador de la renovación del aire se midió el dióxido de carbono (CO2. Resultados: El nivel medio de cloro en el aire fue de 0,4mg/m³ y el de cloroformo de 22µg/m³. Los valores de cloro libre y combinado de todas las piscinas se mantuvieron dentro de los valores reglamentarios. El nivel medio de cloroformo del agua de baño fue de 13,7µg/l. El valor del cloroformo del aire puede predecirse razonablemente (R²=0,85, y las variables predictoras son el cloroformo del agua, el CO2 y el número de bañistas del día. Conclusiones: Los niveles de contaminantes en el agua y en el aire de las piscinas de Guipúzcoa son inferiores a los descritos en otros estudios. Sin embargo, utilizando la concentración de 0,5mg/m³ de cloro total en aire, propuesta como valor de referencia para la protección de los nadadores con actividad intensa, un 20% de las instalaciones superarían dicho valor.Objective: To describe levels of pollutants found in indoor swimming pools in Guipúzcoa (Basque Country, Spain, both in the bathing water and in the air, and to study the association between these pollutants and other variables related to ventilation systems and the use of installations. Methods: Of the 35 indoor swimming pools registered in Guipúzcoa, the 20 most frequently used by swimmers were studied. Each installation was sampled on two nonconsecutive days. Free and

  11. Halliwickov koncept učenja plavanja in ocenjevanje plavalnih veščin: The Halliwick concept of teaching of swimming and assessment of swimming skills: The Halliwick concept of teaching of swimming and assessment of swimming skills:

    Groleger, Katja; Vidmar, Gaj; Vrečar, Irena

    2010-01-01

    The Halliwick concept of teaching of swimming is a comprehensive programme of adaptation to water, learning to breathe, moving in water and swimming, aimed mainly at persons with movement and/or learning disabilities of different age. Assessment of swimming ability is an integral part of the Halliwick concept. The system of Halliwick badges is used, which has recently been supplemented by the Swimming With Independent Measurement (SWIM). There is no data on sensitivity of the SWIM test in the...

  12. A model for the analysis of loss of decay heat removal accident in MTR pool type research reactors

    During a loss of coolant accident leading to total emptying of the reactor pool, the decay heat could be removed through air natural convection. However, under partial pool emptying the core is partially submerged and the coolant circulation inside the fuel element could no more be possible. In such conditions, a core overheat take place, and the heat is essentially diffused from the core to its periphery by combined thermal radiation and conduction. In order to predict fuel element temperature evolution under such conditions a mathematical model is performed. The model is based on a three dimensional geometry and takes into account a variety of core configurations including fuel elements (standard and control), reflector elements and grid plates. The homogeneous flow model is used and the time and space dependent non-linear partial differential fluid conservation equations are solved using a semi-implicit finite difference method. Preliminary tests of the developed model were made by considering a series of hypothetical accidents. In the current framework a loss of decay heat removal accidents in the IAEA benchmark open pool MTR-type research reactor is considered. It is shown that in the case of a low core immersion height no water boiling is observed and the fuel surface temperature rise remains below the melting point of the aluminium cladding. (author)

  13. Calculation and mapping of gamma radiation field in the pool of Apsara reactor

    Theoretical simulation of the radiation transport occurring in the Apsara core and bulk shield was carried out using two different radiation transport codes, MCNP and QADCG. The MCNP is a Monte Carlo based statistical method solving Boltzmann transport equation, where as the latter code QADCG is a point kernel based deterministic method with build-up factor correction. The aim of the simulation was to do a dose mapping and estimate the expected value of gamma dose rates at various locations where experimental measurements were conducted. Details regarding the simulation techniques employed by both the MCNP and QADCG software with reference to the Apsara core and shield geometry and source gamma energy distribution in the fuel plates are presented in this report. Different types of particle tallies requested in MCNP and QADCG are discussed. Details of variance reduction methods employed in reducing the statistical uncertainty of Monte Carlo simulation are also mentioned in the report. The statistical errors associated with Monte Carlo based simulation varied between 3% - 6% in most of the energy bins that contribute to the total fluence and hence to the dose rates. It was observed that the experimental values and the theoretically simulated values match each other closely following a similar trend except for certain experimental locations which had photon flux contributions from extraneous sources like the N-16 activity present in water, beam tubes and pool liner towards shielding corner. It is seen that the theoretical values are found to be larger than experimental values by factors ranging from 1.1 to 3 depending on the water shield thickness. This study served in validation of the experimental measurements conducted by GM counter based teletector and dipole based detectors. In addition, the comparison provided a confirmation of the accuracy of the radiation transport simulation techniques used for dose rate evaluation in case of complex source geometries and

  14. Neutronic temperature determination in irradiation facilities of the RP-0 nuclear reactor

    RP-10 a swimming pool MTR type research reactor that attained power of 10 MW. The neutron temperature has been measurement in four different positions of the reactor at 300Kw of power, for this purpose was used the direct method, proposed for De Corte et al. The results were presented and discussed. (authors)

  15. Motivation and drives in bottom-up developments in natural hazards management: multiple-use of adaptation strategies in Austria

    Thaler, Thomas; Fuchs, Sven

    2015-04-01

    Losses from extreme hydrological events, such as recently experienced in Europe have focused the attention of policymakers as well as researchers on vulnerability to natural hazards. In parallel, the context of changing flood risks under climate and societal change is driving transformation in the role of the state in responsibility sharing and individual responsibilities for risk management and precaution. The new policy agenda enhances the responsibilities of local authorities and private citizens in hazard management and reduces the role of central governments. Within the objective is to place added responsibility on local organisations and citizens to determine locally-based strategies for risk reduction. A major challenge of modelling adaptation is to represent the complexity of coupled human-environmental systems and particularly the feedback loops between environmental dynamics and human decision-making processes on different scales. This paper focuses on bottom-up initiatives to flood risk management which are, by definition, different from the mainstream. These initiatives are clearly influenced (positively or negatively) by a number of factors, where the combination of these interdependences can create specific conditions that alter the opportunity for effective governance arrangements in a local scheme approach. In total, this study identified six general drivers which encourage the implementation of flood storages, such as direct relation to recent major flood frequency and history, the initiative of individual stakeholders (promoters), political pressures from outside (e.g. business companies, private households) and a strong solidarity attitude of municipalities and the stakeholders involved. Although partnership approach may be seen as an 'optimal' solution for flood risk management, in practice there are many limitations and barriers in establishing these collaborations and making them effective (especially in the long term) with the consequences

  16. Energy utilized intelligently. Energy-cooperation between an industrial plant and open-air swimming pool; Energie intelligent genutzt. Energie-Kooperation zwischen Industriebetrieb und Freizeitbad

    Bergjan, B. [agn Paul Niederberghaus und Partner GmbH, Ibbenbueren (Germany)

    2006-07-01

    The open-air bassin AquaMagis at Plettenberg uses the waste heat of the near-by situated Aluminium rolling manufacturing Novelis, which had to be cooled expensively in former times. So operating cost for heating the pool are saved in a five number account, carbon dioxide emissions reduced to about 30 % and the extensive waste heat cooling nearly avoided. (GL)

  17. The radiation risks of the accident spectrum of the Greek research reactor

    The Greek Research Reactor is a 5MW swimming pool type reactor located within Athens area, a large population center of 3081000 inhabitants. The consequence analysis of the reactor focuses on the risks stemming from reactivity, coolant flow blockage, and loss of coolant accidents. Individual doses are estimated to a distance of 20km from the reactor site. Collective exposure and latent health effects for the inhabitants of the region are also calculated. (author)

  18. Description of the RA-3 research reactor as a model facility

    The Argentine RA-3 reactor is described as a model facility for the information to be provided to the IAEA in accordance with the requirements of the Model Additional Protocol. RA-3 reactor was designed as a 5 MW swimming pool reactor, moderated and cooled with light water. Its fuel was 90% enriched uranium. The reactor started its operation in 1967, has been modified and improved in many components, including the core, that now is fueled with moderately enriched uranium

  19. Simulation of a steam bubble transport in the primary system of the pool type lead cooled fast reactors

    Pool-type design makes Lead cooled Fast Reactor (LFR) economically competitive with other advanced reactor designs considered under the Generation IV framework. However, close proximity of steam generator to the core increases the risks associated with Steam Generator Tube Rupture/Leakage (SGTR/SGTL) such as voiding of the core and resulting reactivity insertion and/or local damage (burnout) of fuel rod cladding. Analysis of consequences of SGTL provided in present paper suggests that small bubbles of steam can be dragged by the turbulent coolant flow into the core region. Trajectories of the bubbles are determined by location of the leak, bubbles size and turbulent flow field of lead coolant. The influence of epistemic uncertainty in drag coefficient on prediction of the fraction of bubbles that can reach the core and accumulate in the primary coolant system is discussed in the paper. (author)

  20. The life-extension and upgrade program of the Tsing Hua Open-pool Reactor (THOR) and its research prospectives

    The Tsing Hua Open-Pool Reactor (THOR) has been operated for thirty years. It is the regulations of the ROCAEC that any reactor shall be decommissioned after forty-year operation since the first fuel loading. Therefore, for extending the lifetime of THOR, it is necessary to have a life-extension program to be approved by the ROCAEC and also completed by the year of 1997. At the same time, for proceeding new research purposes, it is planed to upgrade the thermal power of THOR from 1 Wth up to 3 Wth and hopefully to reach the maximum thermal neutron flux of 5x1013 n/cm2.s and the fast flux close to that order. New research directions involve (a) boron-captured neutron cancer therapy (BNCT) (b) small-angle neutron scattering (SANS). (author)

  1. Safety aspects of the cleaning and conditioning of radioactive sludge from spent fuel storage pool on 'RA' Research reactor in the Vinca Institute

    Spent fuel elements from nuclear reactors in the Vinca Institute have been temporary stored in water filled storage pool. Due to the fact that the water in the spent fuel elements storage pool have not been purified for a long time, all metallic components submerged in the water have been hardly corroded and significant amount of the sludge has been settled on the bottom of the pool. As a first step in improving spent fuel elements storage conditions and slowing down corrosion in the storage spent fuel elements pool we have decided to remove the sludge from the bottom of the pool. Although not high, but slightly radioactive, this sludge had to be treated as radioactive waste material. Some safety aspects and radiation protection measures in the process of the spent fuel storage pool cleaning are presented in this paper

  2. Sloshing and fluid-structure interaction in a 400-MWe pool-type advanced fast reactor

    This paper describes the seismic analysis of a 400-MWe advanced fast reactor under 0.3 g SSE ground excitation. Two types of analyses are performed - the sloshing analysis and the fluid-structure interaction analysis. In the sloshing analysis, the sloshing frequency and wave patterns are calculated. The maximum wave height and the sloshing forces exerted on the submerged components and the primary tank are evaluated. In the fluid-structure interaction analysis, the maximum horizontal acceleration for the reactor core and the relative displacement between the reactor core and UIS are examined. The fluid-coupling phenomena between various components are investigated. Seismic stresses at critical areas are examined. The results obtained from this study are very useful to the design of the advanced reactors. Meanwhile, the computer code FLUSTR-ANL has proved to be a useful analytical tool for assessing the complicated seismic fluid-structure interactions and sloshing in the fast reactor systems. 10 refs., 25 figs

  3. Failure Status Design of the Air Operated Valves and Solenoid Valves of Hot Water Layer System in the Open-pool Type Research Reactor

    Since the HWLS has ion exchangers, ionized radionuclides in the hot water layer are also purified. Thus the dose at the pool top should be maintained as low as reasonably achievable when the reactor is in normal operation. The HWLS consists of pumps, ion exchangers, heaters, flow meter orifices, all the necessary inter-connecting pipes, valves, and instruments, located in the HWLS equipment room as shown in Fig. 1. Each component, such as the pump, ion exchanger, strainer, and heater has 100% capacity to ensure that failure of one component does not result in the functional failure of the whole system. The suction line is split to the inlet of each pump to take the pool water to the ion exchangers. The design flow rate passes through the ion exchanger to remove the radioactive ions and impurities, and then go to the heater. The coolant is heated up to the desired temperature and flows back to the upper part of the reactor pool. Demineralized water is also supplied to the reactor pool by the HWLS when the pool water level drops to low level by an evaporation loss in order to maintain the normal pool water level. Operability of the HWLS will be maintained when all valves are fully opened. And, opening status of the valve in the demi-water make-up line has no impact the reactor operation. There are results of the failure status design of the air operated valves and solenoid valves

  4. Demolition of the Karlstein Superheated Steam Reactor Spent Fuel Pool, Germany

    The Karlstein superheated steam reactor started operation in October 1969. A number of failures in the fuel elements, associated with a concept design problem, resulted in final shutdown in April 1971. The reactor was then used as a test bed for reactor safety experiments from 1974 until the end of 1991. The spectrum of experiments simulating accidents under design and beyond design conditions included simulation of aeroplane crashes, earthquake experiments, material parameter studies, loss of coolant accidents (LOCAs), hydrogen distribution, hydrogen deflagration and burning experiments

  5. Liquid sloshing in gravity driven water pool of Advanced Heavy Water Reactor - pool liquid under design seismic load and slosh control studies

    Sloshing phenomenon is well understood in regular cylindrical and rectangular liquid tanks subjected to earthquake. However, seismic behaviour of water in complex geometry such as a sectored annular tank, e.g., Gravity Driven Water Pool (GDWP) which is located in Advanced Heavy Water Reactor (AHWR) need to be investigated in detail in the view of safety significance. Initially, for validation of Computational Fluid Dynamics (CFD) procedure, square and four sectored square tanks are taken. Slosh height and liquid pressure are calculated over time through theoretical and experimental procedures. Results from theoretical and experimental approaches are compared with CFD results and found to be in agreement. The present work has two main objectives. The first one is to investigate the sloshing behaviour in an un-baffled and baffled three dimensional single sector of GDWP of AHWR under sinusoidal excitation. Other one is to study the sloshing in GDWP water using simulated seismic load along the three orthogonal directions. This simulated seismic load is generated from design basis floor response spectrum data (FRS) of AHWR building. For this, the annular tank is modelled along with water and numerical simulation is carried out. The sinusoidal and earthquake excitations are applied as acceleration force along with gravity. For the earthquake case, acceleration-time history is generated compatible to the design FRS of AHWR building. The free surface is captured by Volume of Fluid (VOF) technique and the fluid domain is solved by finite volume method while the structural domain is solved by finite element approach. Un-baffled and baffled tank configurations are compared to show the reduction in wave height under excitation. The interaction between the fluid and pool wall deformation is simulated using a partitioned fluid-structure coupling. In the earthquake case, a user subroutine function is developed to convert FRS in to time history of acceleration in three directions

  6. Welding of stainless steel pool of pressurized water reactor nuclear power station

    The construction of stainless steel lining of million kilowatt grade pressurized water reactor nuclear power station is a new technology. The author introduces its welding method, parameter verification measure and key factors of construction quality control and so on

  7. Polytomous Adaptive Classification Testing: Effects of Item Pool Size, Test Termination Criterion, and Number of Cutscores

    Gnambs, Timo; Batinic, Bernad

    2011-01-01

    Computer-adaptive classification tests focus on classifying respondents in different proficiency groups (e.g., for pass/fail decisions). To date, adaptive classification testing has been dominated by research on dichotomous response formats and classifications in two groups. This article extends this line of research to polytomous classification…

  8. Experimental Measurement and MCNP5 Model of the Gamma Dose Distribution in the University of Utah TRIGA Reactor Pool

    Gamma doses for the University of Utah TRIGA Reactor (UUTR) are estimated based on the MCNP5 model, and by measurements based on the thermo luminescent detectors (TLDs). In the experiment the gamma dose rate above the UUTR core was obtained by placing TLD-400s every 10 cm from the core top up to 150 cm measured from the surface of the UUTR core, and then every 50 cm up to 300 cm. The dose rate was also obtained at the pool surface level using a Ludlum model 19-survey meter. The measurements are obtained at a steady state thermal power of 90 kW. The MCNP5 model closely followed the experimental setup. The MCNP5 values of the dose immediately above the core were just under 30 percent difference compared to the measured values, which is within the TLD response of ± 30 percent. The TLD error is observed to remain fairly constant at around 5% of the mean. As the gamma dose approaches the lower limit for the TLDs (1 rem), the error rises almost exponentially reaching 80%. The difference between the simulated and measured gamma doses increases as the distance from the core increases. This difference at the surface of the UUTR pool is around 90 percent (the experimental gamma dose being 90% higher). The main source of the difference is due to statistical error of the MCNP5 calculation. The larger the size of the geometry, the more computational time is required to reduce the statistical error. Another source of error is the contribution of nitrogen-16 that is generated from (n, p) reaction with oxygen in the reactor pool water. The (n, p) reaction was not considered in our current MCNP5 model. Therefore, the MCNP5 model can be improved as follows: taking into account the fuel burn up that will correlate more accurately dose estimates near the surface of the pool due to the gamma emission from fission fragments, and taking into a consideration a production and transport of nitrogen-16 that will improve the dose estimates especially at the surface of the UUTR core. (author)

  9. Feynman-alpha technique for measurement of detector dead time using a 30 kW tank-in-pool research reactor

    Akaho, E H K; Intsiful, J D K; Maakuu, B T; Nyarko, B J B

    2002-01-01

    Reactor noise analysis was carried out for Ghana Research Reactor-1 GHARR-1, a tank-in-pool type reactor using the Feynman-alpha technique (variance-to-mean method). Measurements made at different detector positions and under subcritical conditions showed that the technique could not be used to determine the prompt decay constant for the reactor which is Be reflected with photo-neutron background. However, for very low dwell times the technique was used to measure the dead time of the detector which compares favourably with the value obtained using the alpha-conventional method.

  10. Feynman-{alpha} technique for measurement of detector dead time using a 30 kW tank-in-pool research reactor

    Akaho, E.H.K. E-mail: nnri@idngh.com; Intsiful, J.D.K.; Maakuu, B.T.; Anim-Sampong, S.; Nyarko, B.J.B

    2002-03-01

    Reactor noise analysis was carried out for Ghana Research Reactor-1 GHARR-1, a tank-in-pool type reactor using the Feynman-{alpha} technique (variance-to-mean method). Measurements made at different detector positions and under subcritical conditions showed that the technique could not be used to determine the prompt decay constant for the reactor which is Be reflected with photo-neutron background. However, for very low dwell times the technique was used to measure the dead time of the detector which compares favourably with the value obtained using the {alpha}-conventional method.

  11. Feynman-α technique for measurement of detector dead time using a 30 kW tank-in-pool research reactor

    Reactor noise analysis was carried out for Ghana Research Reactor-1 GHARR-1, a tank-in-pool type reactor using the Feynman-α technique (variance-to-mean method). Measurements made at different detector positions and under subcritical conditions showed that the technique could not be used to determine the prompt decay constant for the reactor which is Be reflected with photo-neutron background. However, for very low dwell times the technique was used to measure the dead time of the detector which compares favourably with the value obtained using the α-conventional method

  12. A CFD based approach for thermal hydraulic design of main vessel cooling system of pool type fast reactors

    Highlights: ► We study thermal hydraulic design of main vessel cooling system of fast reactors. ► A CFD based approach is proposed for determination of coolant flow rate. ► Effect of cooling system ovality on temperature asymmetry is quantified. ► Suitable flow distribution device is identified to achieve acceptable flow field. ► To compare efficacy of various devices, a flow mal-distribution index is defined. - Abstract: A computational fluid dynamics (CFDs) based approach is proposed for the thermal hydraulic design of the main vessel cooling system for pool type sodium cooled reactors. Usage of the proposed method is demonstrated by applying it to a future Indian commercial fast breeder reactor. Towards quantifying the amount of sodium flow rate for the main vessel cooling system, two-dimensional CFD investigations have been performed. The conjugate conduction–convection models adopted for this purpose are validated against sodium experiments available in literature. The required flow fraction has been determined to be 2.6% of core flow, which is 175.6 kg/s at full power conditions. The heat loss from the hot pool to the cold pool through the main vessel cooling system is estimated to be 10.6 MW at full power and 3.7 MW at 20% power conditions. By detailed three-dimensional CFD studies, the effect of ovality in the main vessel cooling annuli due to manufacturing tolerances has been assessed and the associated circumferential temperature difference in the main vessel is determined to be 14 °C, which is less than the permissible upper limit of 30 °C. The uniformity of sodium flow in the cooling annulus has been investigated by a three-dimensional hydraulic analysis with a view to identify a suitable passive device that can render a uniform velocity distribution. To compare the effectiveness of various devices, a flow mal-distribution index is defined. Detailed parametric studies have been carried out to identify an appropriate porous jet breaker

  13. Decommissioning of the research reactor ASTRA in Seibersdorf, Austria: Determination of exemption limits at the Barite-concrete of the neutron activated biological shield to minimize radioactive waste

    The 10 MW multipurpose M.T.R. research reactor ASTRA at Arcs was in successful operation for 39 years (1960 to 1999) and after the decision of the government to shut it down it was necessary to decommission and dismantle the reactor. A team consisting of former reactor crew staff members was set up to perform the decommissioning. Working instructions for handling and operating sequences and radiation protection were developed. An extensive documentation describes the project. The planning took into account that all the work and operations for decommissioning could be performed inside the existing buildings (confinement or pump room) with the ventilation and radiological monitoring systems in operation. Hence, virtually no possibility for a release of activity to the environment during the whole decommissioning process would exist. In immediate succession and still under the operating license, all experimental facilities and components of the reactor within the vicinity of the core or in intermediate storage within the building (e.g. old beam-tube-inserts) were removed and treated in a first stage of dismantling from 2001 to 2003. In 2002 an environmental impact statement was prepared, the public hearing was held on December 19, 2002 to be followed by a license to decommission, which was granted on April 08, 2003 and was legalized in May 2003. It was intended to take down the structures of the biological shield by cutting blocks of between 7 and 9 tons (limited by the 10-ton-capacity of the crane) from the inactive zones in multiple section planes using wire-cutting techniques, and to get clearance for the material by referencing the surfaces and by additional internal probing.Actual work on the second state of dismantling could only be started after May 2003. It comprised the dismantling of the primary and secondary cooling facilities and the removal of he upper, inactive part of the biological shield (roughly 1600 tons).A building directly attached to the reactor

  14. Inherently safe pool-type reactor as a generator of low-grade heat for district heating, air conditioning and salt water desalination

    The society has a heavy demand for low-grade heat to satisfy its various needs. Different factors govern the expediency of applying nuclear reactors for these purposes. The required capacity of heat sources varies in a very wide range. In a majority of cases heat sources have to be located in the immediate vicinity of the users, therefore, nuclear reactors to be used for heat generation must feature enhanced safety. Pool-type reactors can be successfully used for producing low-grade heat. Owing to their design they feature a very high safety level. The absence of positive pressure excludes the possibility of a sudden rupture of reactor tank (vessel) or a fast loss of coolant. The availability of a large amount of water in the tank ensures long-term accumulation of residual heat. The adopted integral layout of equipment, as well as natural circulation of primary coolant improve reactor reliability and safety even further. Negative temperature coefficients of reactivity provide for reactor self-protection against reactivity accidents. Pool-type reactors can be used in newly established heat supply systems and can be built in the operation systems as well, which allows to reduce fossil fuel consumption by 80-90% depending on local conditions. Pool-type reactor heat can be used for desalinating salt water and for cooling water in absorption refrigerating machines with subsequent utilization of cold water for air conditioning, cooling of special premises, and the like. Pool-type reactors can also generate electric power to their in-house needs as well as household power requirements of a neighboring town. (orig.)

  15. Criticality safety assessment of a TRIGA reactor spent fuel pool under accident conditions

    An overview paper on the criticality safety analysis of a pool type storage for a TRIGA spent fuel at the ''Jozef Stefan'' Institute in Ljubljana, Slovenia, is presented. It was shown in that subcriticality is not guaranteed for some postulated accidents (an earthquake with subsequent fuel rack disintegration resulting in contact fuel pitch). To mitigate this deficiency, a study was made about replacing a certain number of fuel elements in the rack with absorber rods in order to lower the probability for supercriticality to acceptable level. (author)

  16. Swimming Droplets

    Maass, Corinna C.; Krüger, Carsten; Herminghaus, Stephan; Bahr, Christian

    2016-03-01

    Swimming droplets are artificial microswimmers based on liquid droplets that show self-propelled motion when immersed in a second liquid. These systems are of tremendous interest as experimental models for the study of collective dynamics far from thermal equilibrium. For biological systems, such as bacterial colonies, plankton, or fish swarms, swimming droplets can provide a vital link between simulations and real life. We review the experimental systems and discuss the mechanisms of self-propulsion. Most systems are based on surfactant-stabilized droplets, the surfactant layer of which is modified in a way that leads to a steady Marangoni stress resulting in an autonomous motion of the droplet. The modification of the surfactant layer is caused either by the advection of a chemical reactant or by a solubilization process. Some types of swimming droplets possess a very simple design and long active periods, rendering them promising model systems for future studies of collective behavior.

  17. Chernobyl and its consequences for Austria

    First there is a short version of 16 pages. Then a detailed account is given mainly on the activities of the Federal Environment Office and the radiation burden to the population. The chapter headings are 1) The Chernobyl reactor accident 2) The meteorological situation 3) Monitoring of the radioactive contamination in Austria 4) Aims of the radiation measurement activities 5) Initial situation in Austria and first measurements 6) Environmental control 7) Food control 8) Fodder 9) Measures taken to minimise the radiation burden - a chronology 10) Comparison with nuclear tests fallout 11) Dose estimation 12) Radioactive contamination in other European countries. (G.Q.)

  18. Optimisation of the flow path in a conceptual pool type reactor under natural circulation with lead coolant

    This contribution investigates the effects of a bypass flow blocking bottom plate and the influence of the heat transfer between the hot and cold leg in a small pool type reactor cooled through natural convection with lead coolant. The computations are carried out using 3D computational fluid dynamics, where small-detail parts, such as the core and heat exchangers are modeled using a porous media approach. The introduction of full conjugate heat transfer shows that the heat transfer between the hot and cold leg can deteriorate flow in the cold leg and lead to recirculation zones. These zones become even more pronounced with the introduction of a bottom plate, which on the other hand also increases the flow through the core and lowers the maximum temperature in the core by approximately 150 K. Based on the results, redesign suggestions for the bottom plate and the internal wall are made. (author)

  19. Research and manufacture of Rossi-α measurement device for pool thermal reactor based on virtual instrument technology

    This paper designs a set of Rossi-α measurement device for pool thermal reactor based on virtual instrument technology. This device makes PXI-6602 high-speed synchronization counter as the hardware measurement platform. By using Labview 8.5 program, the application program of data acquirement and data process analysis of the measurement device have been designed. In addition, By using Fluke-282 arbitrary waveform generator, one channel square signal which frequency and voltage are respectively defined as 200 Hz and 5 V have been produced. By using application analysis program, the pulse counter simulation test has been completed for this channel square signal. According to the test results, the measurement device reaches the measurement use requirements. (authors)

  20. Some aspects of criticality safety of TRIGA reactor spent fuel pool

    Additional criticality safety analysis of a pool type storage for TRIGA spent fuel at ''Jozef Stefan'' Institute in Ljubljana, Slovenia, is presented. Previous results have shown that subcriticality is not guaranteed for some postulated accidents. To mitigate this deficiency, a study was made about replacing a certain number of fuel elements in the rack with absorber rods. For this purpose Monte Carlo computer code MCNP4A with ENDF-B/V library and detailed three dimensional fuel rack model was used. A short study of different absorber rods design is presented. At first the analysis was done about the number of uniformly mixed absorber rods in the lattice needed to sustain the subcriticality of the storage when pitch is decreased from rack design pitch of 8cm to contact, assuming that the absorber rods remain in their proper positions. Because of supercriticality possibility due to random mixing of the absorber rods during lattice compaction, a probabilistic study was made, sampling the probability density functions for random lattice loadings of the absorber rods. The results show reasonably low probabilities for supercriticality even for fresh 12 wt% enriched standard TRIGA fuel stored in the spent fuel pool. (orig.)

  1. Characterization of radioactive contaminants and water treatment trials for the Taiwan Research Reactor's spent fuel pool

    Huang, Chun-Ping, E-mail: chunping@iner.gov.tw [Institute of Nuclear Energy Research, 1000, Wenhua Road, Jiaan Village, Longtan Township, Taoyuan County 32546, Taiwan, ROC (China); Lin, Tzung-Yi; Chiao, Ling-Huan; Chen, Hong-Bin [Institute of Nuclear Energy Research, 1000, Wenhua Road, Jiaan Village, Longtan Township, Taoyuan County 32546, Taiwan, ROC (China)

    2012-09-30

    Highlights: Black-Right-Pointing-Pointer Deal with a practical radioactive contamination in Taiwan Research Reactor spent fuel pool water. Black-Right-Pointing-Pointer Identify the properties of radioactive contaminants and performance test for water treatment materials. Black-Right-Pointing-Pointer The radioactive solids were primary attributed by ruptured spent fuels, spent resins, and metal debris. Black-Right-Pointing-Pointer The radioactive ions were major composed by uranium and fission products. Black-Right-Pointing-Pointer Diatomite-based ceramic depth filter can simultaneously removal radioactive solids and ions. - Abstract: There were approximately 926 m{sup 3} of water contaminated by fission products and actinides in the Taiwan Research Reactor's spent fuel pool (TRR SFP). The solid and ionic contaminants were thoroughly characterized using radiochemical analyses, scanning electron microscopy equipped with an energy dispersive spectrometer (SEM-EDS), and inductively coupled plasma optical emission spectrometry (ICP-OES) in this study. The sludge was made up of agglomerates contaminated by spent fuel particles. Suspended solids from spent ion-exchange resins interfered with the clarity of the water. In addition, the ionic radionuclides such as {sup 137}Cs, {sup 90}Sr, U, and {alpha}-emitters, present in the water were measured. Various filters and cation-exchange resins were employed for water treatment trials, and the results indicated that the solid and ionic contaminants could be effectively removed through the use of <0.9 {mu}m filters and cation exchange resins, respectively. Interestingly, the removal of U was obviously efficient by cation exchange resin, and the ceramic depth filter composed of diatomite exhibited the properties of both filtration and adsorption. It was found that the ceramic depth filter could adsorb {beta}-emitters, {alpha}-emitters, and uranium ions. The diatomite-based ceramic depth filter was able to simultaneously

  2. Summary of the contributions to reactor safety research commissioned by the Republic of Austria and done by the Forschungszentrum Seibersdorf from 1987 to 1990

    In 1987 the Forschungszentrum Seibersdorf was commissioned by the Republic of Austria with the collaboration in the Nuclear Safety Research Index, the OECD-LOFT-Programme and the International Coordinated Assessment and Application Programme (ICAAP). This report summarises the work done from 1987 to 1990, mainly in the field of thermal hydraulics, fuel rod behaviour and source term. Besides some analyses for experiments done in loops based on BWRs and PWRs of western design the work concentrated on safety researchs for WWERS. (Authors)

  3. Current Status of Activation Analysis Using Tsing Hua Open-Pool Reactor

    Activation analysis may be considered to be one of the most practical applications in the utilization of research reactor. One of the obvious advantages of this method is its high sensitivity for many elements. Using the average research reactor, it is feasible to determine the content of element in various matrices, to an order of as low as 0,001 microgram. Although the detection, sensitivities of other analytical methods also have been improved very much in recent years by using newly developed instruments, these methods can rival the activation analysis in sensitivity for only a certain limited number of elements. Thus, at present, the technique of activation analysis seems to offer the highest sensitivity for the greatest number of elements

  4. Psychometric evaluation of the EORTC computerized adaptive test (CAT) fatigue item pool

    Petersen, Morten Aa; Giesinger, Johannes M; Holzner, Bernhard;

    2013-01-01

    Fatigue is one of the most common symptoms associated with cancer and its treatment. To obtain a more precise and flexible measure of fatigue, the EORTC Quality of Life Group has developed a computerized adaptive test (CAT) measure of fatigue. This is part of an ongoing project developing a CAT v...

  5. Corrosion of aluminium-clad spent fuel in the research reactor RA storage pool, IAEA CRP Corrosion of Research Reactor Aluminium-Clad Spent Fuel in Water no. 11968/RBF

    In the framework of the IAEA CRP 'Corrosion of Research Reactor Aluminium-Clad Spent Fuel in Water' a study on corrosion of aluminium cladding of the TVR-S type of enriched uranium spent fuel elements of the research reactor RA in the storage water pool is examined. The project comprises activities on monitoring of the water chemistry in the RA spent fuel storage pool, periodic corrosion monitoring, metallographic examination of corrosion surfaces and examination of the rack stored previously in the pool according to the strategy and the protocol supplied by the IAEA. This is a 9 month Progress Report on the Programme including brief history, details on spent fuel basins, results of monitoring of chemical parameters and radioactivity of the pool water, and some results of experimental examinations of corrosion process on the aluminium coupon rack, including information on laboratory facilities and equipment used. (author)

  6. Evaluation of the aptitude for the service of the pool of the TRIGA Mark III reactor of the National Institute of Nuclear Research of Mexico

    This work describes the evaluation of the structural integrity of the pool of the TRIGA Mark III reactor of the National Institute of Nuclear Research of Mexico, which was realized in July 2001, as an element to determine those actions for preventive and corrective maintenance which owner must do it for a safety and efficient operation of the component in the next years. (Author)

  7. N-16 power monitoring system of the RP-10 pool-type reactor

    The preliminary results of monitoring of power of the RP-10 nuclear reactor by measuring the activity of gamma radiation 16N content in the coolant are presented. A detector NaI(Tl) placed in a window that communicates the decay tank and the pump room of the primary cooling circuit was used. Measurements were performed for different levels of power, from 0,5 to 10 MW. Results show a linear behavior between the power of operation and the activity of 16N. (orig.)

  8. Progress activity of Thai Research Reactor in 2002

    Thai Research Reactor-1/Modification 1 (TRR-1/M1) is a multipurpose research reactor with nominal power of 2 MW. The reactor is a swimming pool type, cooled and moderate with light water, using the LEU-fuel. TRR-1/M1 has been operated and utilized for various applications such as neutron activation analysis, radioisotope production, gem irradiation, neutron radiography and research works. To expand and promote the utilization of research reactor, the new 10 MW Research Reactor will be established in the Ongkarak Nuclear Research Center (ONRC) project and the project will be finished in the near future. (author)

  9. Optical inspections of research reactor tanks and tank components

    By the end of 1987 worldwide there were 326 research reactors in operation, 276 of them operating more than 10 years, and 195 of them operating more than 20 years. The majority of these reactors are swimming-pool type or tank type reactors using aluminium as structural material. Although aluminium has prooven its excellent properties for reactor application in primary system, it is however subjected to various types of corrosion if it gets into contact with other materials such as mild steel in the presence of destilled water. This paper describes various methods of research reactor tank inspections, maintenance and repair possibilities. 9 figs. (Author)

  10. Significance of coast down time on safety and availability of a pool type fast breeder reactor

    Highlights: • Plant dynamics studies for quantifying the benefits of flow coast down time. • Establishment of minimum flow coast down time required for safety. • Assessment of influence of flow coast down on enhancing plant availability. • Synthesis of thermo mechanical benefits of flow coast down time on component design. - Abstract: Plant dynamic investigation towards establishing the influence of flow coast down time of primary and secondary sodium systems on safety and availability of plant has been carried out based on one dimensional analysis. From safety considerations, a minimum flow coast down time for primary sodium circuit is essential to be provided to limit the consequences of loss of flow event within allowable limits. Apart from safety benefits, large primary coast down time also improves plant availability by the elimination of reactor SCRAM during short term power failure events. Threshold values of SCRAM parameters also need optimization. By suitably selecting the threshold values for SCRAM parameters, significant reduction in the inertia of pumping systems can be derived to obtain desirable results on plant availability. With the optimization of threshold values and primary flow coast down behaviour equivalent to a halving time of 8 s, there is a possibility to eliminate reactor SCRAM during short term power failure events extending up to 0.75 s duration. Benefits of secondary flow halving on reducing transient thermal loading on components have also been investigated and mixed effects have been observed

  11. Safety evaluation report related to the renewal of the operating license for the Worcester Polytechnic Institute open-pool training reactor, Docket No. 50-134

    This Safety Evaluation Report for the application filed by the Worcester Polytechnic Institute (WPI) for a renewal of Operating License R-61 to continue to operate the WPI 10-kW open-pool training reactor has been prepared by the Office of Nuclear Reactor Regulation of the US Nuclear Regulatory Commission. The facility is owned and operated by the Worcester Polytechnic Institute and is located on the WPI campus in Worcester, Worcester County, Massachusetts. The staff concludes that the reactor facility can continue to be operated by WPI without endangering the health and safety of the public

  12. Fukushima - calculation of the reactor core inventory and storage pools Dai-ichi 1 to Dai-ichi 4, an estimation of a source term

    Inventory of the reactor core and spent fuel storage pool of the reactors at Dai-ichi 1 to Dai-ichi 4 was determined to need a realistic estimate of the source (released into the atmosphere environment) and modelling of radiological impact of the events in Fukushima NPP. Calculations of inventories were carried out by the methodology that is used in systems to support emergency response and crisis management anymore. Calculations were made based on a model that respects knowledge of real fuels and fuel cycles for individual reactors Dai-ichi. Necessary input data for training the model and calculate inventories are obtained from the IAEA PRIS database.

  13. Gene characteristics and serotype of adenovirus strains in an outbreak through a municipal swimming pool%经游泳池水传播的腺病毒毒株血清型及基因特征分析

    李秀娟; 田会方; 徐保红; 赵冬; 潘琢; 蒋瑞平

    2012-01-01

    Objective To study the gene characteristics and serotype of adenovirus strains in an outbreak through a municipal swimming pool. Methods The serotype of sixteen adenovirus positive samples detected by using respiratory virus multiple PCR joint inspection kit were tested with tvpe specific primers of adenovirus type 3, 7 and 21. And the completely hexon genes and fiber genes of three adenovirus positive specimens were amplified by polymerase chain reaction (PCR) and completely sequence determination was conducted. Results All the sixteen adenovirus positive samples were human adenovirus type 7. The three adenovirus serotype 7 isolates had the same hexon gene and fiber gene sequence, the nucleic acid homology was 100%. Compared with the adenovirus serotype 7 outbreak in Shaanxi province, China, which associated with a severe lower respiratory tracted disease in infants 7the three adenovirus positive samples and Shaanxi adenovirus strain shared the same sequence,and no significant genetic variations were found. Conclusion The viral pathogen related to the adenovirus in the outbreak through municipal swimming pool is the type 7. Sequences of the hexon gene and fiber gene are similar to the adenovirus serotype 7 strain in the outbreak in Shaanxi province, none variation is found.%目的 研究经游泳池水传播的腺病毒毒株血清型及基因特征.方法 对采用呼吸道病毒多重PCR法检测阳性的16份咽试子样品进行了腺病毒3型、7型及21型的特异性PCR检测,并对其中3份标本进行了腺病毒六联体(hexon)基因和纤毛(fiber)基因的全序列测定,将测定结果与Genbank数据库公开的核酸序列进行同源性比对,绘制进化树.结果 16份腺病毒阳性样品均为腺病毒7型;3份样品间hexon基因和ber基因核酸序列完全一致,同源性为100%;同时,该3份标本的hexon基因和ber基因核酸序列与引起我国陕西省婴儿严重急性下呼吸道感染暴发的腺病毒毒株的核酸序

  14. Design of a decay tank for a pool type research reactor with a CFD model

    A conceptual primary cooling system (PCS) was designed for adequate cooling of the core of a research reactor. The primary coolant after passing through the reactor core contains many kinds of radio-nuclides. A decay tank provides a delayed transit time to ensure that the N-16 activity decreases enough before the coolant leaves the decay tank's shielding room. The size of the decay tank should be enlarged to provide sufficient transit time. However, there was a limitation: to minimize the tank size, it should be designed with an internal baffle, which affects the pressure loss in the system and net positive suction head (NPSH) of the PCS pump. Therefore, the decay tank should be optimized for size and the internal baffle. A vertical type decay tank was chosen to optimize the geometrical arrangement of PCS and the vertical internal baffle was installed to minimize the number of internal structures. The preliminary geometry of the tank and the internal baffle were determined to satisfy the required delayed transit time by calculating the maximum velocity and the flow path length of the circular and the annular sections of the tank. The commercially available CFD model, FLUENT, which solves the Navier-Stokes and turbulent models, was used to specifically design the decay tank with the preliminarily calculated geometry and the related flow rate. Several turbulence models, standard k-ε model, renormalization group (RNG) model, and realizable k-ε model, were conducted to isolate the root cause of these differences. By comparing the results of the velocity profile and the characteristics of each model, a detailed design study was simulated using the realizable k-ε model. A user-defined scalar equation was solved to estimate the delayed transit time. The size and the internal baffle that satisfy the required transit time were determined based on the CFD results. (author)

  15. Piscina cubierta, en Viena, Austria

    Grünberger, Friedrich

    1969-03-01

    Full Text Available This project includes the following: The main building contains the basement, a laundry, the heating and air conditioning installations. The ground floor has men's dressing rooms and showers. The first floor has ladies dressing rooms and individual bathrooms. On the 2nd and 3rd floors there are sauna facilities for men and women and also ladies and gentlemen's hairdressing saloons. The top level is utilized for sunbathing. The intermediate building has two swimming pools, one for learners, and the other for children. Finally the covered swimming pool itself has a full sized pool and a diving structure, 5 m in height. The most outstanding features of this sporting facility are the structures of the buildings, which are made with prestressed concrete.El conjunto construido comprende: El edificio principal, que alberga en el sótano: una lavandería, los cuartos para la calefacción y aire acondicionado; en la planta baja: los vestuarios para hombres, con sus duchas correspondientes; en la 1.ª planta: los vestuarios y duchas para mujeres y los servicios de «baños» individuales; en las plantas 2.ª y 3.ª: «saunas» para mujeres y para hombres, y una peluquería masculina y otra femenina. El nivel superior es utilizado para tomar «baños de sol». El pabellón intermedio contiene las piscinas: para los que aprenden a nadar, y de niños. Finalmente, el edificio de la «Piscina cubierta» propiamente dicha aloja: una piscina reglamentaria y su correspondiente torre de saltos de 5 m de altura. Lo más destacable de este complejo son las estructuras de los edificios y de la piscina, realizadas con hormigón pretensado.

  16. Handling process of assemblies and fuel pins during the re-loading of a nuclear reactor

    The objective of this invention is to propose a process of handling assemblies and fuel pins, when reloading a nuclear reactor enclosing assemblies comprising a skeleton closed at the two ends inside of which fuel pins are disposed in vertical position. The reloading is made with the reactor vessel opened, and comprises: the transfer of fuel assemblies from a position to another in the reactor, the replacements of defective or spent assemblies by new assemblies and different controls using the surrounding swimming pool. Every replaced assembly is taken from the reactor vessel, put in a transfer container and transported in horizontal position in the fuel swimming pool near the reactor, this process allows a better re-use of the fuel pins which have not been completely spent in the changed assemblies using the skeletons of this assemblies during unloading

  17. Is swimming during pregnancy a safe exercise?

    Juhl, Mette; Kogevinas, Manolis; Andersen, Per Kragh; Andersen, Anne-Marie Nybo; Olsen, Jørn

    2010-01-01

    BACKGROUND: Exercise in pregnancy is recommended in many countries, and swimming is considered by many to be an ideal activity for pregnant women. Disinfection by-products in swimming pool water may, however, be associated with adverse effects on various reproductive outcomes. We examined the...... association between swimming in pregnancy and preterm and postterm birth, fetal growth measures, small-for-gestational-age, and congenital malformations. METHODS: We used self-reported exercise data (swimming, bicycling, or no exercise) that were prospectively collected twice during pregnancy for 74......,486 singleton pregnancies. Recruitment to The Danish National Birth Cohort took place 1996-2002. Using Cox, linear and logistic regression analyses, depending on the outcome, we compared swimmers with physically inactive pregnant women; to separate a possible swimming effect from an effect of exercise...

  18. Retrieval of Brain Tumors by Adaptive Spatial Pooling and Fisher Vector Representation.

    Cheng, Jun; Yang, Wei; Huang, Meiyan; Huang, Wei; Jiang, Jun; Zhou, Yujia; Yang, Ru; Zhao, Jie; Feng, Yanqiu; Feng, Qianjin; Chen, Wufan

    2016-01-01

    Content-based image retrieval (CBIR) techniques have currently gained increasing popularity in the medical field because they can use numerous and valuable archived images to support clinical decisions. In this paper, we concentrate on developing a CBIR system for retrieving brain tumors in T1-weighted contrast-enhanced MRI images. Specifically, when the user roughly outlines the tumor region of a query image, brain tumor images in the database of the same pathological type are expected to be returned. We propose a novel feature extraction framework to improve the retrieval performance. The proposed framework consists of three steps. First, we augment the tumor region and use the augmented tumor region as the region of interest to incorporate informative contextual information. Second, the augmented tumor region is split into subregions by an adaptive spatial division method based on intensity orders; within each subregion, we extract raw image patches as local features. Third, we apply the Fisher kernel framework to aggregate the local features of each subregion into a respective single vector representation and concatenate these per-subregion vector representations to obtain an image-level signature. After feature extraction, a closed-form metric learning algorithm is applied to measure the similarity between the query image and database images. Extensive experiments are conducted on a large dataset of 3604 images with three types of brain tumors, namely, meningiomas, gliomas, and pituitary tumors. The mean average precision can reach 94.68%. Experimental results demonstrate the power of the proposed algorithm against some related state-of-the-art methods on the same dataset. PMID:27273091

  19. Adaptation of nuclear reactors to the needs of networks

    Guesdon, B.; Martin, C. (Framatome, Division Procede, 92 - Courbevoie (France)); Miossec, C. (Electricite de France, Service de la Production Thermique, 75 - Paris)

    1985-03-01

    To optimize the production capacity, the following points have to be considered: modulation of the demand, economical constraints (total exploitation costs) and planning of PWR reactor shutdowns. The main constraints being known, the programs of adjustment of the production of the needs are given to the operators of the power plants. Intensive studies have been made for the past eight years by Framatome and the ''EDF'' (The French Electricity Board) to enable pressurized water reactors to adjust their production to the needs of the network. Framatome designed a new pilot mode: mode G which uses new equipment (and increased maneuverability device) and wich should give pressurized water reactors a flexibility which is at least equal to standard thermic power plants.

  20. The adaptation of nuclear reactors to the needs of networks

    To optimize the production capacity, the following points have to be considered: modulation of the demand, economical constraints (total exploitation costs) and planning of PWR reactor shutdowns. The main constraints being known, the programs of adjustment of the production of the needs are given to the operators of the power plants. Intensive studies have been made for the past eight years by Framatome and the ''EDF'' (The French Electricity Board) to enable pressurized water reactors to adjust their production to the needs of the network. Framatome designed a new pilot mode: mode G which uses new equipment (and increased maneuverability device) and wich should give pressurized water reactors a flexibility which is at least equal to standard thermic power plants

  1. Strategies for chemically healthy public swimming pools

    Hansen, Kamilla Marie Speht; Andersen, Henrik Rasmus; Albrechtsen, Hans-Jørgen; Mosbæk, Hans

    2013-01-01

    I Danmark er offentlige svømmebade en vigtig mulighed for rekreative aktiviteter og fysisk træning samt et redskab for genoptræning. Tilsætning af klor anvendes altid til at kontrollere vand¬kvaliteten og hindre spredning af infektioner mellem badende. Klor oxiderer vandforureningen fra de badende, hvilket holder bassinvandet rent, men der dannes klorerede desinfektions¬biprodukter. Der er identificeret mere end 100 klorbiprodukter i svømme¬bads¬vand, hvor nogle har vist sig at være genotoksi...

  2. Investigation of a long term passive cooling system using two-phase thermosyphon loops for the nuclear reactor spent fuel pool

    Highlights: • A passive cooling system using two-phase thermosyphon for the spent fuel pool was proposed. • Effect of fill charge ratio on the two-phase thermosyphon loop performance was analyzed. • A thermo-hydraulic decoupling analysis method was introduced for the passive system. • Natural circulation of water in spent fuel pool was simulated and analyzed. - Abstract: Given postulated accidents that go beyond the plant design basis, long term passive cooling for the nuclear reactor spent fuel pool is important to demonstrate. Large amount of heat transport with small temperature difference is required. Two-phase thermosyphon loops are suitable for these cases. Flow and heat transfer characteristics of a two-phase thermosyphon loop were numerically investigated using RELAP5 code. Effects of fill charge ratio on the heat transfer were analyzed. The fill charge ratio should be chosen between 30% and 80%, smaller than 30% or larger than 80% will reduce the heat transfer. Based on the analysis of two-phase thermosyphon loops, a complete design of a passive cooling system for the spent fuel pool was proposed. An analysis method for decoupling of the thermo-hydraulics of the water natural circulation in spent fuel pool, two-phase flow of ammonia in thermosyphon loop and air natural circulation in cooling tower was presented. The results indicate that 1528 two-phase thermosyphon loops can passively remove 16 MW decay heat from the spent fuel pool successfully. Finally, the velocity and temperature distributions in the spent fuel pool were numerically simulated using ANSYS FLUENT software. It was proved that natural circulation of water in spent fuel pool can be realized with the present design. The temperature uniformity was fairly well and the maximum water temperature was 81 °C

  3. Contributions of research reactors in science and technology

    Butt, N.M.; Bashir, J.

    1994-01-01

    In the present paper, after defining a research reactor, its basic constituents, types of reactors, and their distribution in the world, some typical examples of their uses are given. Particular emphasis is placed on the contribution of PARR-1 (Pakistan Research Reactor-1), the 5MW Swimming Pool Research reactor which first became critical at the Pakistan Institute of Nuclear Science and Technology (PINSTECH) in Dec. 1965 and attained its full power in June 1966. This was and still is the major research facility at PINSTECH for research and development.

  4. Contributions of research Reactors in science and technology

    In the present paper, after defining a research reactor, its basic constituents, types of reactors, their distribution in the world, some typical examples of their uses are given. Particular emphasis in placed on the contribution of PARR-I (Pakistan Research Reactor-I), the 5 MW Swimming Pool Research reactor which first became critical at the Pakistan Institute of Nuclear Science and Technology (PINSTECH) in Dec. 1965 and attained its full power in June 1966. This is still the major research facility at PINSTECH for research and development. (author)

  5. Corrosion resistance of SAV-1 aluminium alloy after operating in the core of the WWR-K reactor and storage in the water pool

    This work was devoted to study of corrosion resistance of the WWR-K fuel assembly shroud material SAV-1 aluminum alloy. The data of monitoring of surface conditions for the casing an automatic control rod and an ejector rod after full operating in the reactor core and long storage in a temporary water pool were presented. Some regularities of corrosion development in material, irradiated with different neutron fluence were obtained.

  6. Development of Power Controller System based on Model Reference Adaptive Control for a Nuclear Reactor

    The Reactor TRIGA PUSPATI (RTP)-type TRIGA Mark II was installed in the year 1982. The Power Controller System (PCS) or Automated Power Controller System (APCS) is very important for reactor operation and safety reasons. It is a function of controlled reactivity and reactor power. The existing power controller system is under development and due to slow response, low accuracy and low stability on reactor power control affecting the reactor safety. The nuclear reactor is a nonlinear system in nature, and it is power increases continuously with time. The reactor parameters vary as a function of power, fuel burnup and control rod worth. The output power value given by the power control system is not exactly as real value of reactor power. Therefore, controller system design is very important, an adaptive controller seems to be inevitable. The method chooses is a linear controller by using feedback linearization, for example Model Reference Adaptive Control. The developed APCS for RTP will be design by using Model Reference Adaptive Control (MRAC). The structured of RTP model to produce the dynamic behaviour of RTP on entire operating power range from 0 to 1MWatt. The dynamic behavior of RTP model is produced by coupling of neutronic and thermal-hydraulics. It will be developed by using software MATLAB/Simulink and hardware module card to handle analog input signal. A new algorithm for APCS is developed to control the movement of control rods with uniformity and orderly for RTP. Before APCS test to real plant, simulation results shall be obtained from RTP model on reactor power, reactivity, period, control rod positions, fuel and coolant temperatures. Those data are comparable with the real data for validation. After completing the RTP model, APCS will be tested to real plant on power control system performance by using real signal from RTP including fail-safe operation, system reliable, fast response, stability and accuracy. The new algorithm shall be a satisfied

  7. Shipment of 255 DIDO fuel elements to the Savannah River Site to empty the storage and reactor pools at Risoe National Laboratory

    The DR-3 reactor, owned and operated by the Danish National Laboratory, was built in the late 1950's and initiated operation in January 1960. At that time the DR-1 and DR-2 reactors were already in operation. The main purpose if of Danish research reactor DR-3 was material and fuel testing. Until 1989 the reactor utilized HEU fuel elements. Conversion to the LEU fuel cycle was accomplished in 1990. DOE restarted the return program of for Foreign Research Reactor fuel elements to the United States in 1994. From that time, through 1998, three IUO4 casks (one cask in 1994) operated by Transnucleaire (now named Cogema Logistics, ACL) were used to transport Risoe's fuel to the Savannah River Site (SRS) near Aiken, SC in the USA. In 1999, Risoe elected to issue a request for proposal to transport DR-3 the DIDO fuel elements to SRS with a new licensed cask designed to replace the IUO4 cask. ACL was awarded the contract to transport the irradiated fuel from DR-3 to SRS for the remainder of the FRR Fuel Return program (2009). However, on September 28, 2000, the Board of Governors of Risoe National Laboratory decided to shut down the Danish research reactor of DR3. There had been of R2 technical problems (corrosion on the aluminum reactor tank) and, due to anticipated increasing operational expenses, the Board elected to close the reactor facility. Shortly thereafter, the Danish Government asked the National Laboratory to empty the reactor and its reactor and storage pools containing a total of 255 Dido irradiated fuel elements and ship them to Savannah Rive Site. At that time, ACL was in the process of licensing the new TN-MTR package in the USA. The early shut down of the DR-3 reactor and consequently the resultant new shipping schedule was not compatible with ACL's equipment and licensing schedule for the cask. (author)

  8. Neutronics and thermohydraulics of the reactor C.E.N.E. Part II; Analisis neutronico y termohidraulico del reactor C.E.N.E. Parte II

    Caro, R.

    1976-07-01

    In this report the analysis of neutronics thermohydraulics and shielding of the 10 HWt swimming pool reactor C.E.N.E is included. In each of these chapters is given a short description of the theoretical model used, along with the theoretical versus experimental checking carried out, whenever possible, with the reactors JEN-I and JEN-II of Junta de Energia Nuclear. (Author) 11 refs.

  9. Neutronics and thermohydraulics of the reactor C.E.N.E.-Part I; Analisis neutronico y termohidraulico del reactor C.E.N.E. Parte I

    Caro, R.; Ahnert, C.; Naudin, A. E.; Martinez Fanegas, R.; Minguez, E.; Rovira, A.

    1976-07-01

    In this report the analysis of neutronics (both statics and kinetics), of the 10 MWt swimming pool reactor C.E.N.E, is included. In each of these chapters is given a short description of the theoretical model used, along with the theoretical versus experimental checking, carried out, whenever possible, with the reactors JEN-I and JEN-II of Junta de Energia Nuclear. (Author) 11 refs.

  10. Irish Literature in Austria.

    Faerber, Gerda

    After a brief description of some historical and cultural interchanges between Ireland and Austria, the paper examines Irish fiction that has been translated into German and Irish plays that have been performed in Vienna over the past 25 years. The paper also describes German translations of Irish children's fiction, including classics like…

  11. Budgeting in Austria

    Jón R. Blöndal; Daniel Bergvall

    2007-01-01

    This article discusses budgeting institutions, processes and practices at the federal level in Austria. Separate sections are devoted to the budget formulation process, the role of parliament, and various aspects of budget implementation and government management issues. Each section highlights the government’s reform agenda and current practices, and analyses the two vis-à-vis OECD best practices.

  12. Organic Agriculture in Austria

    Vogl, C. R.; Darnhofer, I.

    2004-01-01

    Organic farming has a long history in Austria, not least due to the fact that Rudolf Steiner, the founder of the bio-dynamic farming movement, was an Austrian. Currently approximately 10% of Austrian farms are certified organic, the highest percentage in the EU.

  13. Successful scaling-up of self-sustained pyrolysis of oil palm biomass under pool-type reactor.

    Idris, Juferi; Shirai, Yoshihito; Andou, Yoshito; Mohd Ali, Ahmad Amiruddin; Othman, Mohd Ridzuan; Ibrahim, Izzudin; Yamamoto, Akio; Yasuda, Nobuhiko; Hassan, Mohd Ali

    2016-02-01

    An appropriate technology for waste utilisation, especially for a large amount of abundant pressed-shredded oil palm empty fruit bunch (OFEFB), is important for the oil palm industry. Self-sustained pyrolysis, whereby oil palm biomass was combusted by itself to provide the heat for pyrolysis without an electrical heater, is more preferable owing to its simplicity, ease of operation and low energy requirement. In this study, biochar production under self-sustained pyrolysis of oil palm biomass in the form of oil palm empty fruit bunch was tested in a 3-t large-scale pool-type reactor. During the pyrolysis process, the biomass was loaded layer by layer when the smoke appeared on the top, to minimise the entrance of oxygen. This method had significantly increased the yield of biochar. In our previous report, we have tested on a 30-kg pilot-scale capacity under self-sustained pyrolysis and found that the higher heating value (HHV) obtained was 22.6-24.7 MJ kg(-1) with a 23.5%-25.0% yield. In this scaled-up study, a 3-t large-scale procedure produced HHV of 22.0-24.3 MJ kg(-1) with a 30%-34% yield based on a wet-weight basis. The maximum self-sustained pyrolysis temperature for the large-scale procedure can reach between 600 °C and 700 °C. We concluded that large-scale biochar production under self-sustained pyrolysis was successfully conducted owing to the comparable biochar produced, compared with medium-scale and other studies with an electrical heating element, making it an appropriate technology for waste utilisation, particularly for the oil palm industry. PMID:26612557

  14. The use and evolution of the CEA research reactors

    The authors successively examine the different research reactors in use in the French C.E.A. Nuclear Centres. They trace briefly their histories, describing how they have been used up to the present, and how they have been adapted to changes in programme by means of certain modifications. They also describe the reasons which have led to the elaboration of the project for the new reactor Osiris. Zoe, the oldest reactor in the CEA, has been in service in the Centre de Fontenay-aux-Roses since 1948. It is used mainly for measurements of absorption cross-sections in graphite, and for various short irradiations which do not require high fluxes. The reactor EL 2, in service since 1952, was used for the first studies on gas cooling. It has also been widely used for the production of radioisotopes and for a large number of experiments in the fields of physics, metallurgy and physical chemistry. The ageing of certain elements of the reactor has led to the decision to close it down in the near future The reactor EL 3 has been widely used for experiments in physics and in the investigation of fuels. The possibilities of the reactor in fast neutron irradiations will be considerably improved by the adoption of a new type of core (the 'snow crystal' structure). Triton-I, a 2 MW swimming-pool reactor, is used for the most part for fast neutron and gamma irradiations. The modifications being carried out on it at present should result in an increase in the power of the reactor up to 4 or 5 MW. In a neighbouring compartment is housed Triton-II which is of the same general structure, as Triton-I, but whose maximum power is 100 kW. Triton-II is used solely for studies on shielding. Melusine, a 2 MW swimming-pool reactor, has been in use in the Centre d'Etudes Nucleaires de Grenoble since 1959. It has supported a very high programme concerned mainly with solid state physics, fundamental research into refractory fissile materials and special graphites, and the study of the behaviour of

  15. The Measurement of "True" Unemployment in Austria

    Gudrun Biffl

    1997-01-01

    With EU membership Austria has become obliged to adopt the international definitions and concepts for the calculation of the unemployment rate. In 1994 the questionnaire of the microcensus was adapted to the labor force concept used by international organizations. Since the unemployment rate according to the traditional Austrian sources (registered unemployment and social security employment) differs greatly from that according to the household survey (3.7 percent versus 5.9 percent in 1995),...

  16. PROPERTIES OF SWIMMING WATER

    Tayfun KIR; Zakir COBANOÐLU

    2004-01-01

    Swimming waters may be hazardous on human health. So, The physicians who work in the facilities, which include swimming areas, are responsible to prevent risks. To ensure hygiene of swimming water, European Swimming Water Directive offers microbiological, physical, and chemical criteria. [TAF Prev Med Bull 2004; 3(5.000): 103-104

  17. Adaptation of PWR reactors to the needs of the electric network

    After a brief recall on reactor core control and on control modes, the principles of the gray mode control are given. Then, the impact of the adaptation to the needs on the components is examined. Finally, this paper takes stocks of the industrial exploitation while thinking of future perspectives

  18. Adaptation of PWR reactors to the needs of the electric network

    Guesdon, B. (Framatome, Division Procede, 92 - Courbevoie (France))

    1985-01-01

    After a brief recall on reactor core control and on control modes, the principles of the gray mode control are given. Then, the impact of the adaptation to the needs on the components is examined. Finally, this paper takes stocks of the industrial exploitation while thinking of future perspectives.

  19. Neutronics and thermohydraulics of the reactor C.E.N.E.-Part I

    In this report the analysis of neutronics (both statics and kinetics), of the 10 MWt swimming pool reactor C.E.N.E, is included. In each of these chapters is given a short description of the theoretical model used, along with the theoretical versus experimental checking, carried out, whenever possible, with the reactors JEN-I and JEN-II of Junta de Energia Nuclear. (Author) 11 refs

  20. Neutronics and thermohydraulics of the reactor C.E.N.E. Part II

    In this report the analysis of neutronics thermohydraulics and shielding of the 10 HWt swimming pool reactor C.E.N.E is included. In each of these chapters is given a short description of the theoretical model used, along with the theoretical versus experimental checking carried out, whenever possible, with the reactors JEN-I and JEN-II of Junta de Energia Nuclear. (Author) 11 refs

  1. Review of IAEA specialists' meeting on irradiation embrittlement, thermal annealing and surveillance of reactor vessels, Vienna, Austria, 26-28 February 1979

    The basic theme of the meeting was the exposition of knowledge which will permit the evaluation or projection of the reactor pressure vessel condition after neutron irradiation so as to assure vessel integrity for the reactor's economic life. This applies to both current and future light water reactor (LWR) systems. With this basis, the participants, organizers, authors, and discussors freely provided the latest available information as well as ideas for added research and development to meet the theme goal. Papers from Belgium, Czechoslovakia, France, the Federal Republic of Germany, India, Japan, The Netherlands, Sweden, the United Kingdom, and the United States covered various topics within the framework of studies on irradiation embrittlement, surveillance, and thermal annealing to correct radiation damage. The collective result in the long run would be to provide the basic data on which to base criteria for assurance of LWR vessel integrity

  2. Adaptation of INAA method at the IGR reactor

    Full text: The method of instrumental neutron activation analysis allows realizing into practice the selective determination of the activity of radioisotopes and the definition of a considerable number of elements in small samples. The calculated and experimental researches of the possibility of radiation of samples of different composition were performed during development of INAA method. The sensitivity of INAA method on the IGR reactor and relative measurements errors of peaks area of the total absorption in the gamma energy spectrums of samples for specific conditions were determined. Comparing the results of neutronic calculations and experiments, it is possible to note that differences in the values of the rate of a reaction for isotopes are 10 percent

  3. Adaptive fuzzy control of neutron power of the TRIGA Mark III reactor; Control difuso adaptable de la potencia neutronica del reactor Triga Mark III

    Rojas R, E.

    2014-07-01

    The design and implementation of an identification and control scheme of the TRIGA Mark III research nuclear reactor of the Instituto Nacional de Investigaciones Nucleares (ININ) of Mexico is presented in this thesis work. The identification of the reactor dynamics is carried out using fuzzy logic based systems, in which a learning process permits the adjustment of the membership function parameters by means of techniques based on neural networks and bio-inspired algorithms. The resulting identification system is a useful tool that allows the emulation of the reactor power behavior when different types of insertions of reactivity are applied into the core. The identification of the power can also be used for the tuning of the parameters of a control system. On the other hand, the regulation of the reactor power is carried out by means of an adaptive and stable fuzzy control scheme. The control law is derived using the input-output linearization technique, which permits the introduction of a desired power profile for the plant to follow asymptotically. This characteristic is suitable for managing the ascent of power from an initial level n{sub o} up to a predetermined final level n{sub f}. During the increase of power, a constraint related to the rate of change in power is considered by the control scheme, thus minimizing the occurrence of a safety reactor shutdown due to a low reactor period value. Furthermore, the theory of stability in the sense of Lyapunov is used to obtain a supervisory control law which maintains the power error within a tolerance region, thus guaranteeing the stability of the power of the closed loop system. (Author)

  4. Radon in Austria

    Several projects in Austria deal with the problem of enhanced radon exposure to the public. The Austrian Radon Project is the largest project within this task, with the aim of investigating the radon concentrations in Austrian homes. Another project concerns mitigation methods. According to the EU directive EURATOM 96/29 it is also necessary to check working places for possibly enhanced radon concentrations. These projects are and will be funded by the government. The federal government of Upper Austria sponsored a project to test the indoor air quality in kindergartens including radon measurements. Within an EU research project, the radon concentrations in Austrian springs and groundwater were systematically listed and analyzed. Additional investigations will focus on methods to improve the radon potential maps from the Austrian Radon Project by including geological and other information. (author)

  5. Adaptive control using a hybrid-neural model: application to a polymerisation reactor

    Cubillos F.

    2001-01-01

    Full Text Available This work presents the use of a hybrid-neural model for predictive control of a plug flow polymerisation reactor. The hybrid-neural model (HNM is based on fundamental conservation laws associated with a neural network (NN used to model the uncertain parameters. By simulations, the performance of this approach was studied for a peroxide-initiated styrene tubular reactor. The HNM was synthesised for a CSTR reactor with a radial basis function neural net (RBFN used to estimate the reaction rates recursively. The adaptive HNM was incorporated in two model predictive control strategies, a direct synthesis scheme and an optimum steady state scheme. Tests for servo and regulator control showed excellent behaviour following different setpoint variations, and rejecting perturbations. The good generalisation and training capacities of hybrid models, associated with the simplicity and robustness characteristics of the MPC formulations, make an attractive combination for the control of a polymerisation reactor.

  6. Experimental study for research and development of a super fast reactor. (2) Oscillatory condensation of high temperature vapor directly discharged into sub-cooled liquid pool

    The measurement of pressure oscillation and the observation of condensation behavior of a vapor discharge into sub-cooled liquid cool has been carried out to obtain a basic data for the evaluation of safety of the LOCA in the supercritical pressure light water cooled fast reactor (Super Fast Reactor). In the experiment, HCFC 123 is used as the test fluid. HCFC 123 is easy for handling due to its low critical pressure and temperature, and therefore, the experimental conditions can be set easily to make systematic data. The vapor at high temperature is discharged into the sub-cooled liquid pool through a submerged single pipe vertically fixed. The oscillatory condensation is observed. The condensation oscillation produces pressure oscillation in the liquid pool. The condensing interface area becomes small as the increase of the degree of sub-cooling. The pressure frequency has a period of millisecond order and the frequency and amplitude of the pressure oscillation increase with increasing the degree of sub-cooling and mass flux of the vapor, like the results of some conventional water vapor injection tests. In the present study, it is also consistently discussed the influence of the vapor temperature, mass flux, mass flow rate, back pressure of the liquid pool, pipe diameter and the degree of sub-cooling on the pressure amplitude and condensation behavior. (author)

  7. Physics in Austria

    This catalogue gives the results of an investigation on research institutes in Austria in the field of physics, including nuclear physics, which was performed by the Austrian Physical Society. The main part is on university institutes, but also other research institutes are listed. For each institute the name of the head, number of researchers, a short description of the scientific work and an overview of national and international cooperation is given. Various registers and indexes are attached. (A.N.)

  8. Restructuring in SMEs: Austria

    Mandl, Irene

    2013-01-01

    Based on information derived from 85 case studies across all EU Member States and other sources, the project outlines the features peculiar to SMEs in their anticipation and management of restructuring, explores the main drivers of change and analyses the factors influencing successful restructuring. It offers some insight into how restructuring impacts on workers and the company itself and sets out several policy pointers for future action. This is the country report for Austria.

  9. Nonlinear Adaptive Dynamic Output-Feedback Power-Level Control of Nuclear Heating Reactors

    Zhe Dong

    2013-01-01

    Full Text Available Due to the high safety performance of small nuclear reactors, there is a promising future for small reactors. Nuclear heating reactor (NHR is a small reactor that has many advanced safety features such as the integrated arrangement, natural circulation at any power levels, self-pressurization, hydraulic control rod driving, and passive residual heating removing and can be applied to the fields of district heating, seawater desalination, and electricity production. Since the NHR dynamics has strong nonlinearity and uncertainty, it is meaningful to develop the nonlinear adaptive power-level control technique. From the idea of physically based control design method, a novel nonlinear adaptive power-level control is given for the NHR in this paper. It is theoretically proved that this newly built controller does not only provide globally asymptotic closed-loop stability but is also adaptive to the system uncertainty. Numerical simulation results show the feasibility of this controller and the relationship between the performance and controller parameters.

  10. Final IAEA research coordination meeting on plasma-interaction induced erosion of fusion reactor materials. October 9-11, 1995, Vienna, Austria. Summary report

    The proceedings and results of the Final IAEA Research Coordination Meeting on ''Plasma-interaction Induced Erosion of Fusion Reactor Materials'' held on October 9, 10 and 11, 1995 at the IAEA Headquarters in Vienna are briefly described. This report includes a summary of presentations made by the meeting participants, the results of a data survey and needs assessment for the erosion of plasma facing components and in-vessel materials, and recommendations regarding future work. (author). Refs, figs, tabs

  11. Reracking of fuel pools, experience with improved codes and design for reactor sites with high seismic loads

    Reracking of existing pools to the maximum extent is desirable from the economical point of view. Although the load onto the storage rack structure and the fuel pool bottom will be increased, new improved codes, optimized structural qualification procedures and advanced design enable to demonstrate the structural integrity for all normal and accident conditions so that the design provides a safe compact storage of spent fuel under any condition.(author)

  12. EFFECTS OF THREE FEEDBACK CONDITIONS ON AEROBIC SWIM SPEEDS

    Pedro Pérez Soriano

    2009-03-01

    Full Text Available The purpose of this study was twofold: (a to develop an underwater chronometer capable to provide feedback while the athlete is swimming, as well as being a control tool for the coach, and (b to analyse its feedback effect on swim pace control compared with feedback provided by the coach and with no feedback, in 25 m and 50 m swimming pools. 30 male swimmers of national level volunteer to participate. Each swimmer swam 3 x 200 m at aerobic speed (AS and 3 x 200 m just under the anaerobic threshold speed (AnS, each swam repetition with a different feedback condition: chronometer, coach and without feedback. Results (a validate the chronometer system developed and (b show that swimmers pace control is affected by the type of feedback provided, the swim speed elected and the size of the swimming pool

  13. Sex-specific genetic differences in endurance swimming of Trinidadian guppies

    Gordon, Swanne; Chen, Yun Yi; Yamashita, Karalynn; Bejar, Christopher; Wilshire, Adam; Cheung, Vinson

    2015-01-01

    Swim performance is considered a main fitness-determining trait in many aquatic organisms. Swimming is generally the only way most aquatic prey can escape predation, and swimming capacity is directly linked to food capture, habitat shifts, and reproduction. Therefore, evolutionary studies of swim performance are important to understand adaptation to aquatic environments. Most studies, however, concentrate on the importance of burst-swim responses to predators, and little is ...

  14. Activities for extending the lifetime of MINT research reactor

    Bokhari, Adnan; Kassim, Mohammad Suhaimi [Malaysian Inst. for Nuclear Technology Research (MINT), Bangi, Kajang (Malaysia)

    1998-10-01

    MINT TRIGA Reactor is a 1-MW swimming pool nuclear reactor commissioned in June 1982. Since then, it has been used for research, isotope production, neutron activation, neutron radiography and manpower training. The total operating time till the end on September 1997 is 16968 hours with cumulative total energy release of 11188 MW-hours. After more than fifteen years of successful operation, some deterioration in components and associated systems has been observed. This paper describes some of the activities carried out to increase the lifetime and to reduce the shutdown time of the reactor. (author)

  15. Corrosion of aluminium alloy test coupons in the WWR-K reactor cooling pool and wet storage tank in Almaty, Kazakhstan

    The corrosion of a number of aluminium alloy coupons was studied. The coupons were assembled in racks and exposed to water in the storage pools for spent nuclear fuels of the WWR-K reactor in Almaty, Kazakhstan. The maximum duration of exposure of the racks was 921 days. Mass loss of the coupons, depth of pits and the average pit sizes on the coupons were determined. The data was evaluated and compared as a function of coupon position in the rack, time of exposition and nature of contact between coupons (none, crevice or bimetallic). (author)

  16. Resistance to irradiation of micro-algae growing in the storage pools of a nuclear reactor investigated by NMR and neutron spectroscopies

    A green Chlorophycean micro-alga surviving high irradiation doses has been discovered in the storage pools of a nuclear reactor. Investigating the mechanisms sustaining its properties is of peculiar interest. Metabolic impact of irradiation on the micro-alga as well as structural macromolecular impact were investigated using nuclear magnetic resonance and neutron backscattering spectroscopy. Carbohydrate, amino acid and organic acid content studied as a function of the irradiation dose revealed an intense protein repair activity. Resilience was extracted according to irradiation dose and compared to that of other extremophile species. (authors)

  17. GIF-IAEA Workshop on Safety Design Criteria for Sodium- Cooled Fast Reactors, 26-27 February 2013, IAEA, Vienna, Austria. Opening Remarks

    This meeting is the first step of a 2-week “marathon” for the Fast Reactor community: the present workshop and the GIFIAEA-INPRO Interface Meeting this Thursday and Friday, and finally, the FR13 Conference next week in Paris, which – it is worth mentioning – also includes a Panel where the outcomes of this Workshop will be presented to, and discussed with, about 700 participants from all over the world. This Workshop has also a particular meaning as it represents a fundamental milestone in the close collaboration between the Generation IV International Forum and the IAEA in the field of safety of sodium-cooled fast reactors. Let me briefly remind you that the first GIF–IAEA joint SFR workshop, titled “Operational and Safety Aspects of Sodium-Cooled Fast Reactors”, was held in June 2010 and mainly addressed the operating experience and the safety fundamentals of SFR designs, as well as the safety characteristics and goals of the future SFRs. Then, the second joint Workshop held in November 2011, just some months after the March 11th tragic event, was particularly focused on the safety implications of the lessons learned from the Fukushima-Daiichi accident on the design of innovative SFRs. Another important issue discussed in the second Workshop was how to harmonize the safety approaches and goals for the next generation SFRs, thus contributing to the harmonization of the safety criteria for GEN IV sodium-cooled fast reactors. As a natural follow-up of the second GIF-IAEA Joint Workshop, this Workshop is devoted to the safety design criteria for SFR, including safety approach and requirements on general plant design. Let me underline that the discussion on the safety design criteria for innovative SFRs comes at a very timely moment as, on one side the GIF has just released its first interim report on the subject which will constitute the basis for the discussion in this workshop, and on the other side the IAEA has been starting to critically review the

  18. Ciliary-propelling mechanism, effect of temperature and viscosity on swimming speed, and adaptive significance of ‘jumping’ in the ciliate Mesodinium rubrum

    Riisgård, Hans Ulrik; Larsen, Poul Scheel

    2009-01-01

    Beating cilia are important organelles, not only for water pumping in many active filter-feeding organisms, but also for the swimming activity of ciliates and other aquatic organisms that use cilia for propulsion. The present study concerns the effect of temperature-dependent viscosity of the amb...

  19. SWIMMING CLASSES IN JUNIOR HIGH SCHOOL STUDENTS’ OPINION

    Grzegorz Bielec

    2013-02-01

    Full Text Available The role of modern physical education is not only to develop motor abilities of the students, but most of all prevent them from epidemic youth diseases such as obesity or postural defects. Positive attitudes to swimming as a long-life physical activity, instilled in adolescence should be beneficial in adult life. The group of 130 boys and 116 girls of 7th grade junior high school (mean age 14.6 was asked in the survey to present their opinion of obligatory swimming lessons at school. Students of both sexes claimed that they liked swimming classes because they could improve their swimming skills (59% of answers and because of health-related character of water exercises (38%. 33% of students regarded swimming lessons as boring and monotonous, and 25% of them complained about poor pool conditions like chlorine smell, crowded lanes, too low temperature. Majority of the surveyed students saw practical role of swimming in saving others life.

  20. ARC Code TI: Swim

    National Aeronautics and Space Administration — Swim is a software information service for the grid built on top of Pour, which is an information service framework developed at NASA. Swim provides true software...

  1. Thai research reactor

    The Office of Atomic Energy for Peace (OAEP) was established in 1962, as a reactor center, by the virtue of the Atomic Energy for Peace Act, under operational policy and authority of the Thai Atomic Energy for Peace Commission (TAEPC); and under administration of Ministry of Science, Technology and Energy. It owns and operates the only Thai Research Reactor (TRR-1/M1). The TRR-1/M1 is a mixed reactor system constituting of the old MTR type swimming pool, irradiation facilities and cooling system; and TRIGA Mark III core and control instrumentation. The general performance of TRR-1/M1 is summarized in Table I. The safe operation of TRR-1/M1 is regulated by Reactor Safety Committee (RSC), established under TAEPC, and Health Physics Group of OAEP. The RCS has responsibility and duty to review of and make recommendations on Reactor Standing Orders, Reactor Operation Procedures, Reactor Core Loading and Requests for Reactor Experiments. In addition,there also exist of Emergency Procedures which is administered by OAEP. The Reactor Operation Procedures constitute of reactor operating procedures, system operating procedures and reactor maintenance procedures. At the level of reactor routine operating procedures, there is a set of Specifications on Safety and Operation Limits and Code of Practice from which reactor shift supervisor and operators must follow in order to assure the safe operation of TRR-1/M1. Table II is the summary of such specifications. The OAEP is now upgrading certain major components of the TRR-1/M1 such as the cooling system, the ventilation system and monitoring equipment to ensure their adequately safe and reliable performance under normal and emergency conditions. Furthermore, the International Atomic Energy Agency has been providing assistance in areas of operation and maintenance and safety analysis. (author)

  2. HEALTHY AND SAFETY SWIMMING

    Suleyman CEYLAN

    2005-01-01

    Swimming is a sport which has own rules, styles, and fields, however, is one of the most performed avocation as amateur and a joke especially at summer months. Although one of the most beneficial sports, swimming can cause a number of several health problems such as infectious diseases, allergic events, or traumas, if it is not done at adequate conditions and eligible style. In this paper, the factors such as preparing to swimming, health and safety features of swimming areas, important healt...

  3. Performance diagnosis in swimming

    J. P. Vilas-Boas; Fernandes, R.J.; Barbosa, Tiago M; Keskinen, K.L.

    2007-01-01

    Energy expenditure as a function of swimming velocity is one of the major topics of interest in swimming science. Understanding the mechanisms behind swimming performance and training need new scientific approaches, while most of the existing knowledge on the bioenergetics of the four swimming strokes has already a number of years. The purpose of this presentation is to synthesize the most recent contributions of our research group in the domain of the bioenergetic evaluation of the swi...

  4. Saksa skandaal ja Austria / Heiki Suurkask

    Suurkask, Heiki, 1972-

    2000-01-01

    Saksamaa korruptsiooniskandaal. J. Haideri Vabaduspartei valitsuse koosseisus. Kumb on suurem ohu allikas? Vt. samas art. Habsburg: Austria ei ole banaanivabariik. Austria mitteametliku troonipärija arvamus

  5. Pools for the Handicapped.

    American School and University, 1979

    1979-01-01

    Three institutions in Ohio now stress hydrotherapy and water recreation as important parts of individual educational programs for the handicapped. Specially designed and adapted pools provide freedom of movement and ego building as well as physical education and recreation. (Author)

  6. Evaluation of final vapor pressures in the loss of flow accident in an irradiation device of a pool reactor core

    The reliability feature, are described for a device containing samples, at a temperatures of 300 grade centigrades, in a reactor core for a long time. After an examination of the maximum accident event, the maximum vapour pressure originated by the inlet of reactor cooling water into the experimental device, is evaluated

  7. Nondestructive testing of PWR type fuel rods by eddy currents and metrology in the OSIRIS reactor pool

    The Saclay Reactor Department has developed a nondestructive test bench, now installed above channel 1 of the OSIRIS reactor. As part of investigations into the dynamics of PWR fuel degradation, a number of fuel rods underwent metrological and eddy current inspection, after irradiation

  8. Swimming Safely (A Minute of Health with CDC)

    2014-05-22

    Almost 4,000 people die from drowning each year in the U.S. You can also get sick at the pool. This podcast discusses swimming pool safety tips.  Created: 5/22/2014 by MMWR.   Date Released: 5/22/2014.

  9. Third Joint GIF–IAEA Workshop on Safety Design Criteria for Sodium-Cooled Fast Reactors, 26-27 February 2013, Vienna, Austria. Summary Report

    The main objectives of the meeting were to: • Present and share information on the work carried out by GIF, the IAEA and the Member States on the definition of safety design criteria for SFR, including safety approach and requirements on general plant design; • Present the document prepared by the GIF-SFR Task Force on Safety Design Criteria; • Present and discuss safety design concepts of SFRs under development in Member States, with particular emphasis on design measures against Design Basis Accidents and Design Extended Conditions, as well as the associated safety evaluations and supporting R&D; • Draft a room document which should be the basis of the discussion for the Panel on Safety Design Criteria of the FR13 Conference in Paris. • Discuss the results and agree on the future actions of the 3rd Joint GIF-IAEA Workshop on Safety of Sodium-Cooled Fast Reactors

  10. Puente en Melk, Austria

    Schmidt, W.

    1974-05-01

    Full Text Available This interesting bridge across the Danube links the central forest zone with the highway Ceste and contributes greatly to facilitate the intense traffic of this region. It has a total length of 818 m, distributed in nine spans: the two central ones over the river are 190 m each with box girders. A great many problems have bean solved successfully regarding the various foundations, slender beams, processes of concreting, the temperature of concrete, and the most adequate design and realisation all of which makes this work one of the most important ones that have been constructed in Austria during recent years.Este interesante puente sobre el Danubio enlaza la zona boscosa central con la autopista Oeste y contribuye grandemente a aligerar el denso tráfico de esta zona. Tiene una longitud total de 818 m, distribuidos en nueve tramos; los dos centrales, sobre el río, alcanzan los 190 m cada uno, con vigas de cajón. Se han resuelto acertadamente numerosos problemas, relacionados con las variadas cimentaciones adoptadas, esbeltez de canto en las vigas, procesos de hormigonado, temperatura del hormigón y el cálculo y ejecución más adecuados; todo lo cual hace de esta obra una de las más importantes que se han realizado en Austria durante los últimos años.

  11. Some particular aspects of control in nuclear power reactors

    This paper reviews the experience acquired in France on the question, of reactor safety. Since a special paper is being presented on reactors of the graphite gas type, the safety of the other types studied in France is discussed here: - heavy water-gas reactors, - fast neutron reactors, - water research reactors of the swimming-pool and tank types. The safety rules peculiar to the different types are explained, with emphasis on their influence on the reactor designs and on the power limits they impose. The corresponding safety studies are presented, particular stress being placed on the original work developed in these fields. Special mention is made of the experimental systems constructed for these studies: the reactor CABRI, pile loop for depressurization tests, loops outside the pile, mock-ups etc. (authors)

  12. Conceptual design of multipurpose compact research reactor

    Conceptual design of the high-performance and low-cost multipurpose compact research reactor which will be expected to construct in the nuclear power plant introduction countries, started from 2010 in JAEA and nuclear-related companies in Japan. The aims of this conceptual design are to achieve highly safe reactor, economical design, high availability factor and advanced irradiation utilization. One of the basic reactor concept was determined as swimming pool type, thermal power of 10MW and water cooled and moderated reactor with plate type fuel element same as the JMTR. It is expected that the research reactors are used for human resource development, progress of the science and technology, expansion of industry use, lifetime extension of LWRs and so on. (author)

  13. The reactor Cabri

    It has become necessary to construct in France a reactor which would permit the investigation of the conditions of functioning of future installations, the choice, the testing and the development of safety devices to be adopted. A water reactor of a type corresponding to the latest CEA constructions in the field of laboratory or university reactors was decided upon: it appeared important to be able to evaluate the risks entailed and to study the possibilities of increasing the power, always demanded by the users; on the other hand, it is particularly interesting to clarify the phenomena of power oscillation and the risks of burn out. The work programme for CABRI will be associated with the work carried out on the American Sperts of the same type, during its construction, very useful contacts were made with the American specialists who designed the se reactors. A brief description of the reactor is given in the communication as well as the work programme for the first years with respect to the objectives up to now envisaged. Rough description of the reactor. CABRI is an open core swimming-pool reactor without any lateral protection, housed in a reinforced building with controlled leakage, in the Centre d'Etudes Nucleaires de Cadarache. It lies alone in the middle of an area whose radius is 300 meters long. Control and measurements equipment stand out on the edge of that zone. It consumes MTR fuel elements. The control-safety rods are propelled by compressed air. The maximum flow rate of cooling circuit is 1500 m3/h. Transient measurements are recorded in a RW330 unit. Aims and work programme. CABRI is meant for: - studies on the safety of water reactors - for the definition of the safety margins under working conditions: research of maximum power at which a swimming-pool reactor may operate with respect to a cooling accident, of local boiling effect on the nuclear behaviour of the reactor, performances of the control and safety instruments under exceptional

  14. Finding the best swimming sheet

    Ives, Tom; Morozov, Alexander

    2014-11-01

    Many microorganisms propel through fluid environments by undulating their bodies or long thin organelles (flagella). The particular waveform of the undulations can often be changed by the organism to adapt to particular environmental conditions. It has been proposed in the literature that this adaptation is driven by the desire to optimise the swimming efficiency. However, it remains an open question as to whether this is indeed the optimised quantity for microorganisms. We study propulsion in Newtonian fluids at zero inertia for a model organism, the so-called Taylor waving sheet. We develop a numerical method that allows us to calculate flow fields for sheets of arbitrary waverforms in the bulk and next to a wall. We perform optimisations of various quantities that can potentially be optimised by a swimming microorganisms (efficiency, speed, etc.) and present the optimal waveforms. We also present a simple analytical model that yields similar results. We conclude that various optimal waveforms are very similar, both in the bulk and next to a boundary, and one cannot claim that optimising the swimming efficiency is the strategy adopted by undulating microorganisms. SUPA, School of Physics & Astronomy, University of Edinburgh, UK.

  15. 用于池式快堆系统分析的钠池三维模型开发%Development of Three-Dimensional Sodium Pool Model for System Analysis of Pool-Type Liquid Metal Fast Breeder Reactor

    隋丹婷; 陆道纲; 张盼

    2012-01-01

    由于池式快堆钠池内的热工水力学特性对反应堆的安全运行有重要影响,本文采用基于交错网格的SIMPLE算法开发直角坐标系和柱坐标系下钠池三维计算软件.应用CFX软件进行验证之后,完成了三维流场分析程序与系统分析软件SAC-CFR的耦合,并用耦合后的程序分析日本文殊快堆45%功率稳态运行工况上腔室内的流场分布,初步验证了堆芯上腔三维化的SAC-CFR用于系统分析的有效性,为进一步开发事故模型、非能动余热排出系统模型做准备.%As the thermal-hydraulic characteristic in sodium pool is crucial for safety operation of liquid metal fast breeder reactor (LMFBR), a three-dimensional sodium pool thermal-hydraulic analysis code was developed based on SIMPLE algorithm on stagger grid under Cartesian coordinates and cylindrical coordinates. After the validation with CFX, coupling between the analysis code and SAC-CFR was completed) and then the coupled code was applied to the flow field analysis in upper plenum of Monju Plant at 45% thermal power steady-state operation condition, which preliminary shows the effectiveness of the system analysis with coupled code and makes preparations for further development of accident analysis model and passive residual heat removal system.

  16. ADAPTATION OF CRACK GROWTH DETECTION TECHNIQUES TO US MATERIAL TEST REACTORS

    A. Joseph Palmer; Sebastien P. Teysseyre; Kurt L. Davis; Gordon Kohse; Yakov Ostrovsky; David M. Carpenter; Joy L. Rempe

    2015-04-01

    A key component in evaluating the ability of Light Water Reactors to operate beyond 60 years is characterizing the degradation of materials exposed to radiation and various water chemistries. Of particular concern is the response of reactor materials to Irradiation Assisted Stress Corrosion Cracking (IASCC). Some test reactors outside the United States, such as the Halden Boiling Water Reactor (HBWR), have developed techniques to measure crack growth propagation during irradiation. The basic approach is to use a custom-designed compact loading mechanism to stress the specimen during irradiation, while the crack in the specimen is monitored in-situ using the Direct Current Potential Drop (DCPD) method. In 2012 the US Department of Energy commissioned the Idaho National Laboratory and the MIT Nuclear Reactor Laboratory (MIT NRL) to take the basic concepts developed at the HBWR and adapt them to a test rig capable of conducting in-pile IASCC tests in US Material Test Reactors. The first two and half years of the project consisted of designing and testing the loader mechanism, testing individual components of the in-pile rig and electronic support equipment, and autoclave testing of the rig design prior to insertion in the MIT Reactor. The load was applied to the specimen by means of a scissor like mechanism, actuated by a miniature metal bellows driven by pneumatic pressure and sized to fit within the small in-core irradiation volume. In addition to the loader design, technical challenges included developing robust connections to the specimen for the applied current and voltage measurements, appropriate ceramic insulating materials that can endure the LWR environment, dealing with the high electromagnetic noise environment of a reactor core at full power, and accommodating material property changes in the specimen, due primarily to fast neutron damage, which change the specimen resistance without additional crack growth. The project culminated with an in

  17. Adaptive fuzzy control of neutron power of the TRIGA Mark III reactor

    The design and implementation of an identification and control scheme of the TRIGA Mark III research nuclear reactor of the Instituto Nacional de Investigaciones Nucleares (ININ) of Mexico is presented in this thesis work. The identification of the reactor dynamics is carried out using fuzzy logic based systems, in which a learning process permits the adjustment of the membership function parameters by means of techniques based on neural networks and bio-inspired algorithms. The resulting identification system is a useful tool that allows the emulation of the reactor power behavior when different types of insertions of reactivity are applied into the core. The identification of the power can also be used for the tuning of the parameters of a control system. On the other hand, the regulation of the reactor power is carried out by means of an adaptive and stable fuzzy control scheme. The control law is derived using the input-output linearization technique, which permits the introduction of a desired power profile for the plant to follow asymptotically. This characteristic is suitable for managing the ascent of power from an initial level no up to a predetermined final level nf. During the increase of power, a constraint related to the rate of change in power is considered by the control scheme, thus minimizing the occurrence of a safety reactor shutdown due to a low reactor period value. Furthermore, the theory of stability in the sense of Lyapunov is used to obtain a supervisory control law which maintains the power error within a tolerance region, thus guaranteeing the stability of the power of the closed loop system. (Author)

  18. Biomechanical analysis of the swim-start: a review.

    Vantorre, Julien; Chollet, Didier; Seifert, Ludovic

    2014-05-01

    This review updates the swim-start state of the art from a biomechanical standpoint. We review the contribution of the swim-start to overall swimming performance, the effects of various swim-start strategies, and skill effects across the range of swim-start strategies identified in the literature. The main objective is to determine the techniques to focus on in swimming training in the contemporary context of the sport. The phases leading to key temporal events of the swim-start, like water entry, require adaptations to the swimmer's chosen technique over the course of a performance; we thus define the swim-start as the moment when preparation for take-off begins to the moment when the swimming pattern begins. A secondary objective is to determine the role of adaptive variability as it emerges during the swim-start. Variability is contextualized as having a functional role and operating across multiple levels of analysis: inter-subject (expert versus non-expert), inter-trial or intra-subject (through repetitions of the same movement), and inter-preference (preferred versus non-preferred technique). Regarding skill effects, we assume that swim-start expertise is distinct from swim stroke expertise. Highly skilled swim-starts are distinguished in terms of several factors: reaction time from the start signal to the impulse on the block, including the control and regulation of foot force and foot orientation during take-off; appropriate amount of glide time before leg kicking commences; effective transition from leg kicking to break-out of full swimming with arm stroking; overall maximal leg and arm propulsion and minimal water resistance; and minimized energy expenditure through streamlined body position. Swimmers who are less expert at the swim-start spend more time in this phase and would benefit from training designed to reduce: (i) the time between reaction to the start signal and impulse on the block, and (ii) the time in transition (i.e., between gliding and leg

  19. Effects of Nanofluid for In-Vessel Retention External Reactor Vessel Cooling on Critical Heat Flux using Pool Boiling Experiments

    In-vessel retention (IVR) is one of the severe accident management (SAM) strategies that are used in some nuclear power plants: AP600, AP1000, Loviisa and APR1400. One way of IVR is the method of external reactor vessel cooling (ERVC). When core melts and deposits on the bottom of reactor vessel, ERVC is starting to flood the reactor cavity to remove the decay heat through the wall of the reactor vessel. This process can improve the plant economics by reducing regulatory requirements. And increased safety margin leads to gain public acceptance. In this system, the heat removal is restricted by thermal limit called by critical heat flux (CHF). Besides, as advanced light water reactors such as South Korea's APR-1400, thermal safety margin is deceased. So, it is essential to get more safety margin. There are some approaches to enhance the ERVC: using the coating on the vessel outer surface, increasing the reactor cavity flood level, streamlining the gap between the vessel and the vessel insulation. Many investigations have been performed to evaluate the coolability of IVR In this paper, we firstly investigated the coating effects in the critical heat flux among the above mentioned approach methods. During the boiling phenomenon, a thin layer was formed on the heater surface in the nanofluid. This coating mechanism is well known theoretically. Nanofluids are colloidal dispersions of nanoparticles in traditional heat transfer fluids. One of the most interesting characteristics of nanofluids is their capability to enhance the critical heat flux (CHF) significantly. Nanofluid is made by typical particle materials. Materials of nanoparticles include metals (e.g., silver, copper, gold), metal oxides (e.g., titania, alumina, silica, zirconia), carbon allotrope (e.g., carbon nanotube, graphite). We selected the grapheneoxide nanofluid which is a kind of carbon allotrope. Graphene-oxide is attractive material with the high thermal conductivity and stable dispersion ability in

  20. Adapting Pd Gains with Neural Network for Egyptian Second Research Reactor (ETRR-2)

    There is no doubt that selection of conventional Pd gains has a great influence over the system performance. So, this paper presents a developed adapted Pd (APD) control system to fit suitable control action. This system is based on ANN to select, on-line, the proper gains for Pd controller. Both Pd and developed APD control systems are simulated with Egyptian Second Research Reactor (ETRR-2) model subjected to different perturbations. Simulation results proved that, APD controller has faster response than Pd, besides its capability of absorbing more reactivity variations

  1. Survey of Different Types of Communication in Swimming Education

    Biro, Melinda

    2007-01-01

    Study aim: To evaluate verbal and non-verbal behaviour of teachers and pupils in elementary swimming education and their impact on pupils' achievements. Material and methods: A total of 77 swimming lessons were videorecorded and coded with the modified Cheffers' Adaptation of Flanders Interaction Analysis System (CAFIAS); 46 PE teachers, swimming…

  2. Immersion and invariance adaptive control of a class of continuous stirred tank reactors

    Gaiyan HONG; Xiangbin LIU; Hongye SU

    2015-01-01

    An immersion and invariance (I&I) manifold based adaptive control algorithm is presented for a class of continuous stirred tank reactors (CSTR) to realize performance-oriented control in this paper. The nonlinear contraction method is combined into the control law design to render the closed-loop CSTR system globally asymptotically stable, firstly. Then, the I&I method is used to form the adaptation law such that the off-the-manifold coordinate (the parameter estimation error) converges to zero using P-monotone property enforced by selecting tuning function in manifold. As a result, the state of the closed-loop CSTR converges to its desired value asymptotically. The simulation is given to illustrate the effectiveness of the presented algorithm.

  3. Intercomparison of the finite difference and nodal discrete ordinates and surface flux transport methods for a LWR pool-reactor benchmark problem in X-Y geometry

    The aim of the present work is to compare and discuss the three of the most advanced two dimensional transport methods, the finite difference and nodal discrete ordinates and surface flux method, incorporated into the transport codes TWODANT, TWOTRAN-NODAL, MULTIMEDIUM and SURCU. For intercomparison the eigenvalue and the neutron flux distribution are calculated using these codes in the LWR pool reactor benchmark problem. Additionally the results are compared with some results obtained by French collision probability transport codes MARSYAS and TRIDENT. Because the transport solution of this benchmark problem is close to its diffusion solution some results obtained by the finite element diffusion code FINELM and the finite difference diffusion code DIFF-2D are included

  4. Swimming hall water treatment

    Valtonen, Jukka

    2015-01-01

    The purpose of this thesis was to see how ultraviolet light-treatment can improve water disinfection at Pori central swimming hall. The swimming hall has already an option for ultraviolet disinfection system, but there hasn’t been any immediate need for it to be utilized in combination with more conventional water treatment methods. Nevertheless, growing visitor numbers are already straining the swimming hall’s water treatment systems and some improvement was h...

  5. Study of new structures adapted to gas-graphite and gas-heavy water reactors

    The experience acquired as a result of the operation of the Marcoule reactors and of the construction and start-up of the E.D.F. reactors on the one hand, and the conclusions of research and tests carried out out-of-pile on the other hand, lead to a considerable change in the general design of reactors of the gas-graphite type. The main modifications envisaged are analysed in the paper. The adoption of an annular fuel element and of a down-current cooling will make it possible to increase considerably the specific power and the power output of each channel; as a result there will be a considerable reduction in the number of the channels and a corresponding increase in the size of the unit cell. The graphite stack will have to be adapted to there new conditions. For security reasons, the use of prestressed concrete for the construction of the reactor vessel is becoming more widespread; they could lead to the exchangers and the fuel-handling apparatus becoming integrated inside the vessel (the so-called 'attic' device). A full-size mode) of this attic has been built at Saclay with the participation of EURATOM; the operational results obtained are presented as well as a new original design for the control rods. As for as the gas-heavy-water system is concerned, the research is carried out on two points of design; the first, which retains the use of horizontal pressure tubes, takes into account the experience acquired during the construction of the EL 4 reactor of which it will constitute an extrapolation; the second, arising from the research carried out on the gas-graphite system, will use a pre-stressed concrete vessel for holding the pressure, the moderator being almost at the same pressure as the cooling fluid and the fuel being placed in vertical channels. The relative merits of these two variants are analysed in the present paper. (authors)

  6. Swimming Orientation for Preschoolers.

    Smith, Mary Lou

    1990-01-01

    Techniques which are designed to dispel fears and promote confident learning are offered to preschool swimming instructors. Safety, class organization, water games, and class activities are discussed. (IAH)

  7. One-dimensional thermohydraulic model of the nucleus and lower and upper pool regions of the reactor RMB

    The computer codes used in construction of nuclear reactors projects, specifically with regard to the thermo-hydraulics concepts part of your core, whose main goal reproduce actual operating conditions in order to predict quantitatively the limiting conditions of operation so that the safety limit is not exceeded. Computational methods for studies of fluid flow are developed around the world, including Brazil. With the evolution of computers application of numerical methods greatly reduced response time results, and tends to further decrease the extent that the computers and processors develop, making it feasible to use programming accident simulations of heat transfer reactors. The software developed in this paper presents a method for analyzing the thermo-hydraulic behavior of the Brazilian Multipurpose Reactor (RMB) after its shutdown. The software solves the conservations equations applied to the core and also the lower and upper regions of the RMB. The thermo-hydraulics characteristics studied are: the temperatures of the core, cladding and refrigerant, the mass flow and the heat transfer. The numerical resolution was performed using the Matlab language and the outputs are presented in graphs and tables forms. (author)

  8. Application of adaptive hierarchical sparse grid collocation to the uncertainty quantification of nuclear reactor simulators

    Yankov, A.; Downar, T. [University of Michigan, 2355 Bonisteel Blvd, Ann Arbor, MI 48109 (United States)

    2013-07-01

    Recent efforts in the application of uncertainty quantification to nuclear systems have utilized methods based on generalized perturbation theory and stochastic sampling. While these methods have proven to be effective they both have major drawbacks that may impede further progress. A relatively new approach based on spectral elements for uncertainty quantification is applied in this paper to several problems in reactor simulation. Spectral methods based on collocation attempt to couple the approximation free nature of stochastic sampling methods with the determinism of generalized perturbation theory. The specific spectral method used in this paper employs both the Smolyak algorithm and adaptivity by using Newton-Cotes collocation points along with linear hat basis functions. Using this approach, a surrogate model for the outputs of a computer code is constructed hierarchically by adaptively refining the collocation grid until the interpolant is converged to a user-defined threshold. The method inherently fits into the framework of parallel computing and allows for the extraction of meaningful statistics and data that are not within reach of stochastic sampling and generalized perturbation theory. This paper aims to demonstrate the advantages of spectral methods-especially when compared to current methods used in reactor physics for uncertainty quantification-and to illustrate their full potential. (authors)

  9. Base isolation technique for tokamak type fusion reactor using adaptive control

    In this paper relating to the isolation device of heavy structure such as nuclear fusion reactor, a control rule for reducing the response acceleration and relative displacement simultaneously was formulated, and the aseismic performance was improved by employing the adaptive control method of changing the damping factors of the system adaptively every moment. The control rule was studied by computer simulation, and the aseismic effect was evaluated in an experiment employing a scale model. As a results, the following conclusions were obtained. (1) By employing the control rule presented in this paper, both absolute acceleration and relative displacement can be reduced simultaneously without making the system unstable. (2) By introducing this control rule in a scale model assuming the Tokamak type fusion reactor, the response acceleration can be suppressed down to 78 % and also the relative displacement to 79 % as compared with the conventional aseismic method. (3) The sensitivities of absolute acceleration and relative displacement with respect to the control gain are not equal. However, by employing the relative weighting factor between the absolute acceleration and relative displacement, it is possible to increase the control capability for any kind of objective structures and appliances. (author)

  10. Steady-state thermal hydraulic analysis of the equilibrium core of Pakistan research reactor-1

    Steady-state thermal hydraulic analysis of Pakistan Research Reactor-1 (PARR-1) has been carried out. RELAP5/Mod 3.4 (a best-estimate system code) was employed. PARR-1 is a swimming pool type research reactor using MTR (Material Testing Reactor) type fuel. It uses low enriched uranium (<20%) fuel with light water flowing from top to bottom under gravity. Standard correlations were employed to compute various parameters, which include: coolant velocity distribution in the core; critical velocity; pressure drop; saturation temperature; temperature distribution in the core, OFI (onset of flow instability) and DNB (departure from nucleate boiling)

  11. Utilization Status and Development Layout of Research Reactors in Tsinghua University, China

    The Institute of Nuclear and New Energy Technology of Tsinghua University (INET), as the largest education institute of nuclear science in P.R. China, operates three research reactors. How to broaden the utilization of our RRs is the challenge we have to face. In this article, current utilization status of the swimming pool reactor will be introduced. The feasibility of developing the RRs into training center and the advantages of High Temperature Gas-Cooled Reactor (HTR-10) for nuclear hydrogen production will be put forward. (author)

  12. Steady-state thermal hydraulic analysis of the equilibrium core of Pakistan research reactor-1

    Bokhari, I.H. [SDTP User Group, Department of Nuclear Engineering, Pakistan Institute of Engineering and Applied Sciences, P.O. Nilore 45650, Islamabad (Pakistan)], E-mail: ihbokhari@yahoo.co.uk; Mahmood, T.; Chaudri, K.S. [SDTP User Group, Department of Nuclear Engineering, Pakistan Institute of Engineering and Applied Sciences, P.O. Nilore 45650, Islamabad (Pakistan)

    2007-10-15

    Steady-state thermal hydraulic analysis of Pakistan Research Reactor-1 (PARR-1) has been carried out. RELAP5/Mod 3.4 (a best-estimate system code) was employed. PARR-1 is a swimming pool type research reactor using MTR (Material Testing Reactor) type fuel. It uses low enriched uranium (<20%) fuel with light water flowing from top to bottom under gravity. Standard correlations were employed to compute various parameters, which include: coolant velocity distribution in the core; critical velocity; pressure drop; saturation temperature; temperature distribution in the core, OFI (onset of flow instability) and DNB (departure from nucleate boiling)

  13. The Effect of Pregnant Rat Swimming on Hypoxia-Inducible Factor-1α Levels of Neonatal Lung

    Hajizade A

    2012-03-01

    Full Text Available Background: Uterine environment and fetal period can profoundly affect health of the neonat. Hypoxia-inducible factor-1α (HIF-1α is a transcription factor that regulates cellular stress responses and its activity is essential in both embryogenesis and postnatal life. The aim of the present study was to investigate the effects of maternal swimming on rat Pups' HIF-1α levels as a key regulator of oxygen in lungs.Methods: Sixteen female Wistar rats weighing 180- 200 grams were acclimated to a new environment consisting of equal light-darkness cycle and ad lib access to chow and adapted to the stress caused by water for two weeks. The rats were divided into two swimming and control groups. Swimming training began on the first day of pregnancy in a pool and continued for 3 weeks (1 h/day, 5 days/wk. Pups' lungs were removed two days after birth and their HIF-1α concentration was determined with enzyme-linked immunosorbent assay (ELISA. Statistical analysis of the data was done using independent t-test. A p-value smaller than 0.05 was considered statistically significant. Results: Swimming lead to a significant (P<0.001 increase in the Pups' lung HIF-1α levels compared with the control group. Although 3-wk period of swimming training, showed no significant increase in weight and also lung weight of newborns. Thus it can be concluded that swimming endurance training in pregnancy, can be considered as appropriate alternative in order to embryos development. Conclusion: Our research suggests that HIF-1α level is an essential element for the development of the lungs of embryos. Moreover, further studies on the lung HIF-1α levels at post-natal period with different modes of exercise will provide more clear insight into the mechanisms of the findings resulting from this study.

  14. Thread Pool Size Adaptive Adjusting Algorithm Based on Segmentation%基于分段的线程池尺寸自适应调整算法

    孙旭东; 韩江洪; 刘征宇; 解新胜

    2011-01-01

    提出一种基于分段的线程池尺寸自适应调整算法.该算法将用户请求量分为上升段、平衡段和下降段3段,根据当前用户请求数、线程数自适应调整线程池尺寸,从而满足用户需求.实验结果表明,相比基于平均数的调整算法,该算法能更好地处理并发的用户请求,响应时间更短.%This paper presents a thread pool size adaptive adjusting algorithm based on segmentation. User request quantity is divided into rising balancing and dropping section. This algorithm changes the size of the thread pool based on present request and thread in order to meet need of user requirement. Experimental results show that this algorithm can effectively process multiple concurrent requests, its response time is shorter compared with adjusting algorithm based average value.

  15. A Neural-Network-Based Nonlinear Adaptive State-Observer for Pressurized Water Reactors

    Zhe Dong

    2013-10-01

    Full Text Available Although there have been some severe nuclear accidents such as Three Mile Island (USA, Chernobyl (Ukraine and Fukushima (Japan, nuclear fission energy is still a source of clean energy that can substitute for fossil fuels in a centralized way and in a great amount with commercial availability and economic competitiveness. Since the pressurized water reactor (PWR is the most widely used nuclear fission reactor, its safe, stable and efficient operation is meaningful to the current rebirth of the nuclear fission energy industry. Power-level regulation is an important technique which can deeply affect the operation stability and efficiency of PWRs. Compared with the classical power-level controllers, the advanced power-level regulators could strengthen both the closed-loop stability and control performance by feeding back the internal state-variables. However, not all of the internal state variables of a PWR can be obtained directly by measurements. To implement advanced PWR power-level control law, it is necessary to develop a state-observer to reconstruct the unmeasurable state-variables. Since a PWR is naturally a complex nonlinear system with parameters varying with power-level, fuel burnup, xenon isotope production, control rod worth and etc., it is meaningful to design a nonlinear observer for the PWR with adaptability to system uncertainties. Due to this and the strong learning capability of the multi-layer perceptron (MLP neural network, an MLP-based nonlinear adaptive observer is given for PWRs. Based upon Lyapunov stability theory, it is proved theoretically that this newly-built observer can provide bounded and convergent state-observation. This observer is then applied to the state-observation of a special PWR, i.e., the nuclear heating reactor (NHR, and numerical simulation results not only verify its feasibility but also give the relationship between the observation performance and observer parameters.

  16. Experimental and numerical investigations on roof slab of a pool type sodium cooled fast reactor based on model studies

    Highlights: • The structural integrity of the roof slab of 500 MWe sodium cooled fast reactor is predicted under static loading conditions. • A scaling down approach was adopted to reduce the cost of experimentation. • Experiments on 1/12th scaled down model of the roof slab made of Perspex material are carried out and test data is compared with the results of numerical simulation. • The investigations carried out on the model demonstrate the robustness of the analysis as well as raise the confidence on the structural integrity of the roof slab. - Abstract: The objective of the work is to predict the structural integrity of the roof slab of 500 MWe sodium cooled fast reactor (SFR) under static loading conditions. The roof slab is an annular box type structure consisting of top and bottom plates with connecting stiffeners and has been designed to support various components such as control plug, pumps and heat exchangers entering into the main vessel of the reactor. The net static load acting on it is about 3800 t under normal condition and about 5000 t under design basis earthquake. Experiments on 1/12th scaled down model of the roof slab are carried out and test data is compared with the results of numerical simulation by finite element analysis. The numerical as well as experimental investigations carried out on the model demonstrate the robustness of assumptions made for the analysis carried out towards respecting design code limits as well as raise the confidence on the structural integrity of the roof slab

  17. Effect of coupon orientation on corrosion behavior of aluminium alloy coupons in the spent fuel storage section of the IEA-R1 research reactor pool

    Full text: The objectives of the IAEA sponsored Regional Technical Co-operation Project for Latin America (Argentina, Brazil, Chile, Mexico, and Peru) are to provide the basic conditions to define a regional strategy for managing spent fuel and to provide solutions, taking into consideration the economic and technological realities of the countries involved. In particular, to determine the basic conditions for managing research reactor (RR) spent fuel during operation and interim storage as well as final disposal, and to establish forms of regional cooperation for spent fuel characterization, safety, regulation and public communication. This project is divided into 4 subprojects: (1) spent fuel characterization; (2) safety and regulation; (3) options for spent fuel storage and disposal; (4) public information and communication. Corrosion monitoring and surveillance is one of the activities of the subproject 'spent fuel characterization'. The dominant fuel type used in the Latin American (LA) RRs is plate-type (MTR), LEU, oxide fuel (U3O8-Al) clad in Al, followed by TRIGA-type (U-Zr-H) rods. Almost all the spent fuels from LA RRs are stored in storage racks within the reactor pool, in decay pools or in away-from-reactor wet basins. Two of the countries participating in the Regional Project (Argentina and Brazil) were (and continue to be) participants of the IAEA sponsored coordinated research project (CRP) on 'Corrosion of research reactor Al-clad spent fuel in water'. The corrosion surveillance activities of the Regional Project are based on this CRP. The main objective of this activity is to evaluate the effect of LA spent fuel basin parameters on the corrosion behaviour of RR fuel cladding. This evaluation consists of exposing racks containing Al alloy and stainless steel coupons at the different spent fuel basins. Al alloy coupons fabricated under conditions similar to those used to prepare fuel plates have been used. The surface conditions of the Al coupons

  18. Manageable reactor pressure vessel surveillance programme - Flexible and adaptable to innovations

    The surveillance programme (SP) calls upon to predict ahead reactor pressure vessel (RPV) materials characteristics conservatively to guarantee RPV structural integrity without any compromise. General vice of existing SPs is an impossibility of SP changing and development during reactor operation (30, 60 and even more years). Up to day, approach based on initial hard nomenclature of surveillance specimens installed in capsules. Therefore, practically it is impossible to change anything in SP during RPV service life. Anachronistic principle of ahead of time, for some decades of years in advance fabrication and installation into reactor vessel the sets of surveillance specimens (SS) without taking into account quantitative and qualitative changes of norms; state of the present-day science, testing methods and technique contradict to request of RPV operational monitoring technologies innovative development during long-term light water reactor (LWR) operation. We propose to improve LWR SPs by means of passage from existing 'hard' SPs to 'flexible' manageable SPs (MSP) that would give the possibility of SP adaptation to requirements of time and to strengthen technical and scientific potential of investigators and researchers in the future. So, we believe that it makes no sense to leave present-day level of knowledge and technology in frozen state to the next generation of researchers. Thus for new LWRs with a service life of 60 and more years we propose to pass from the SSs of routine nomenclature to MSP i.e. sets of archive materials coupons placed in non-hermetic containers and cooled directly by running water. It gives a perspective in case of need to put into practice an innovative MSP taking into account the state-of-the-art safety standards, technical progress, present day level of science and technology. (author)

  19. SAFETY AND MANAGEMENT OF SWIMING POOLS

    Cemal GÜNDOĞDU

    2008-04-01

    Full Text Available In this study,it was investigated the situation related to the safety and management of swimming pools belongs to municipality This study was planned to determine the present situation related to the safety and management of open,half-olympic and closed swimming pools which are especially used for sports activities,to find out the deficiencies in practise and to overcome these.Our study included totally 80 open,closed,olympic, half-olympic public swimming pools(the pools that belongs to municipality,private administration and university,the colleges connected to the ministry of education, Military schools and police college.In our research,search,natural observation and meeting methods were used.In accordance with this aim the checklist questions,which were prepared for health and safety controls in swimming pools, were tested on the people by face-to-face meeting method. While the statistical evaluation of the available results were being done,frequency and percentage dispersion obtained from checklist was found.It was found that the 52 % of the training and lifeguard choise of the pools in Turkey,64 % of the emergency action equipment,71 % of the signs and signboards for the safety of the pool,75 % of the pool edge and its surroundings are not suitable for the standards and that these threaten the swimmers health importantly.Consequently,we are in the opinion that the pool staff should receive the periodical training about the first aid and using emergency situation equipment.And it is necessary that the Ministry Responsible for sports,Ministry of Interior,Ministry of Health,Ministry of Tourism be cooperate with water sports federations and the related civil society organizationsKey Words: .

  20. Loss of Coolant Accident Analysis for Israel Research Reactor

    One of the main objectives of reactor safety systems is to keep the reactor core in condition that does not permit any release of radioactivity into the environment. In order to ensure this, the reactor must have sufficient safety margins during all possible operational and accident conditions. This paper focuses on the analysis of loss of coolant accident (LOCA), which is one of the most severe scenarios among other hypothetical events such as reactivity induced accidents, loss of flow accident, etc. The analysis was carried out for the Israel Research Reactor 1 (IRR-1), which is a 5MW swimming pool type research reactor. The IRR-1 core consists of MTR highlyenriched uranium (HEU) fuel type, and is reflected by Graphite elements. During normal operation, the reactor core is cooled by downward forced flow of light water circulated by a primary cooling circuit pump. But during shutdown stage, the reactor core is cooled by upward natural convection flow through a safety flapper valve. There could be several primary causes to initiate a LOCA in research reactors, such as breaks in the piping system, ruptures of the beam tubes, and concrete wall failures of the reactor pool. Although probability of large break accident in research reactors is very low, once the accident occurs, it may cause major core damages, so it must be considered

  1. Swimming type inspection device and system thereof

    The present invention provides a swimming type inspection device which can be reduced in the size, easily accessible to each portion of a reactor, and increase the degree of freedom of swimming and visual range, and facilitate visual inspection. The swimming type inspection device comprises two photographing devices, a device which can obtain propelling force by rotation of impellers, two second propelling devices having impellers disposed in perpendicular to the rotating axis of the impellers of the first propelling device, a control device for controlling control signals of first and second propelling devices and driving devices therefor and control image signals of the photographing devices, and transmission section for wireless transmitting of the control signals and the image signals. (N.H.)

  2. The Effect of Concurrent Visual Feedback on Controlling Swimming Speed

    Szczepan Stefan

    2016-03-01

    Full Text Available Introduction. Developing the ability to control the speed of swimming is an important part of swimming training. Maintaining a defined constant speed makes it possible for the athlete to swim economically at a low physiological cost. The aim of this study was to determine the effect of concurrent visual feedback transmitted by the Leader device on the control of swimming speed in a single exercise test. Material and methods. The study involved a group of expert swimmers (n = 20. Prior to the experiment, the race time for the 100 m distance was determined for each of the participants. In the experiment, the participants swam the distance of 100 m without feedback and with visual feedback. In both variants, the task of the participants was to swim the test distance in a time as close as possible to the time designated prior to the experiment. In the first version of the experiment (without feedback, the participants swam the test distance without receiving real-time feedback on their swimming speed. In the second version (with visual feedback, the participants followed a beam of light moving across the bottom of the swimming pool, generated by the Leader device. Results. During swimming with visual feedback, the 100 m race time was significantly closer to the time designated. The difference between the pre-determined time and the time obtained was significantly statistically lower during swimming with visual feedback (p = 0.00002. Conclusions. Concurrently transmitting visual feedback to athletes improves their control of swimming speed. The Leader device has proven useful in controlling swimming speed.

  3. Functional reliability evaluation of an MTR-pool type research reactor core using the load–capacity interference model

    Highlights: • Load–capacity concept is used for reliability evaluation. • Functional Reliability is evaluated in normal operation. • Status of reactor core in normal operation is considered as multiple states. • Latin Hypercube Sampling is used for sampling in uncertainty propagation. • Core heat transfer coefficient is identified as the dominant parameter. - Abstract: This paper presents the functional reliability evaluation of Tehran Research Reactor (TRR) core in normal operation. The concept of functional reliability, borrowed from reliability physics, uses the well-known resistance–stress or load–capacity interference model that is used in the structural reliability framework. To use the load–capacity interference model, uncertainties of significant parameters in system performance are propagated into system dynamics modeled with RELAP5/Mod 3.2 using Latin Hypercube Sampling (LHS) method and exceedance probability (EP) model is used as quantification method. The proposed method in this paper solves a common problem in reliability analysis, i.e., lack of sufficient failure data in specific operating conditions. Although defining failure criteria in normal operation are difficult, this paper focuses on the application of multiple states criteria to determine the status of a system. The status of the reactor core in normal operation is considered multiple states regarding to a performance representative parameter that is temperature in this work. Outlet temperatures of fuel hot and average channels were selected to be performance indicators in normal operation. Consulting with TRR engineers and operators as well as safety analysis report, two failure states were considered exceeding 65.1 °C and 58.9 °C for the hot channel and 50.4 °C and 45.6 °C for the average channel as upper and lower limits respectively. The calculated reliability was 9.1e−01 with 95% of confidence interval, which is in good agreement with experimental results. Using

  4. HTR research and development in Austria. 1982-1984 progress report

    Due to Austria's participation in the OECD Dragon project, a considerable amount of R and D work has been performed and is still going on in several selected areas related to high-temperature gas cooled reactors. These areas are: High temperature reactor fuels; High temperature structural materials; High temperature helium test rig prestressed concrete pressure vessels

  5. Biomechanical Analysis of the Swim-Start: A Review

    Julien Vantorre, Didier Chollet, Ludovic Seifert

    2014-06-01

    Full Text Available This review updates the swim-start state of the art from a biomechanical standpoint. We review the contribution of the swim-start to overall swimming performance, the effects of various swim-start strategies, and skill effects across the range of swim-start strategies identified in the literature. The main objective is to determine the techniques to focus on in swimming training in the contemporary context of the sport. The phases leading to key temporal events of the swim-start, like water entry, require adaptations to the swimmer’s chosen technique over the course of a performance; we thus define the swim-start as the moment when preparation for take-off begins to the moment when the swimming pattern begins. A secondary objective is to determine the role of adaptive variability as it emerges during the swim-start. Variability is contextualized as having a functional role and operating across multiple levels of analysis: inter-subject (expert versus non-expert, inter-trial or intra-subject (through repetitions of the same movement, and inter-preference (preferred versus non-preferred technique. Regarding skill effects, we assume that swim-start expertise is distinct from swim stroke expertise. Highly skilled swim-starts are distinguished in terms of several factors: reaction time from the start signal to the impulse on the block, including the control and regulation of foot force and foot orientation during take-off; appropriate amount of glide time before leg kicking commences; effective transition from leg kicking to break-out of full swimming with arm stroking; overall maximal leg and arm propulsion and minimal water resistance; and minimized energy expenditure through streamlined body position. Swimmers who are less expert at the swim-start spend more time in this phase and would benefit from training designed to reduce: (i the time between reaction to the start signal and impulse on the block, and (ii the time in transition (i

  6. Proposal of novel method of continuous monitoring of possible fuel failure of a pool-type reactor

    During the course of studies on fuel failure detection, we have found that the bubbling of a gas such as nitrogen into a reactor coolant water effectively purges the dissolved fission rare gases (89Kr, T1/2=3.15 min, and 138Xe, T1/2=14.08 min) and that the respective daughter nuclides (89Rb, T1/2=15.15 min and 138Cs, T1/2=33.41 min) are detected in the washing water of the collected gas mixture. The detected activity depends on the time of standing between sampling and washing of the gas, and the dependence agreed well with the theoretical prediction from the consecutive radioactive decay for both pairs (89Kr-89Rb, and 138Xe-138Cs). Based on these findings, we have recently constructed a semi-continuous fuel monitoring system, which consists of an automatic and intermittent gas sampler (1 litre bottles) and a bottle conveying unit. After standing for a definite time, bottled gas is shaken with a small amount of water, and the activity of the water is measured. This system operates satisfactorily, but the whole system involves several sophisticated steps so that is rather costly. Quite recently we have got an idea of a simpler, more economical, fully automated continuous system. The system consists in principle only of a large cylinder with packing materials just as in a fractional distiller. On the top of the cylinder there are an inlet of washing water and an outlet of the gas, and at the bottom there are an inlet of the collected gas from the coolant and an outlet of the washing water. The whole system can be operated fully automatically and continuously, with continuous feeding of bubbling gas into the reactor coolant. This has not yet been experimentally tested at present, and in this presentation, information about the setup parameters such as the flow rate of the bubbling gas, the volume of the cylinder and vacant space, the flow rate of the washing water, etc. are reported

  7. INITIATORS AND TRIGGERING CONDITIONS FOR ADAPTIVE AUTOMATION IN ADVANCED SMALL MODULAR REACTORS

    Katya L Le Blanc; Johanna h Oxstrand

    2014-04-01

    It is anticipated that Advanced Small Modular Reactors (AdvSMRs) will employ high degrees of automation. High levels of automation can enhance system performance, but often at the cost of reduced human performance. Automation can lead to human out-of the loop issues, unbalanced workload, complacency, and other problems if it is not designed properly. Researchers have proposed adaptive automation (defined as dynamic or flexible allocation of functions) as a way to get the benefits of higher levels of automation without the human performance costs. Adaptive automation has the potential to balance operator workload and enhance operator situation awareness by allocating functions to the operators in a way that is sensitive to overall workload and capabilities at the time of operation. However, there still a number of questions regarding how to effectively design adaptive automation to achieve that potential. One of those questions is related to how to initiate (or trigger) a shift in automation in order to provide maximal sensitivity to operator needs without introducing undesirable consequences (such as unpredictable mode changes). Several triggering mechanisms for shifts in adaptive automation have been proposed including: operator initiated, critical events, performance-based, physiological measurement, model-based, and hybrid methods. As part of a larger project to develop design guidance for human-automation collaboration in AdvSMRs, researchers at Idaho National Laboratory have investigated the effectiveness and applicability of each of these triggering mechanisms in the context of AdvSMR. Researchers reviewed the empirical literature on adaptive automation and assessed each triggering mechanism based on the human-system performance consequences of employing that mechanism. Researchers also assessed the practicality and feasibility of using the mechanism in the context of an AdvSMR control room. Results indicate that there are tradeoffs associated with each

  8. Possibility of adapting high-temperature reactors with steam turbines to European conditions

    The studies being carried out by the French Commissariat a l'Energie Atomique as part of its HTR and steam generator programme have brought home the need for adaptations some of which are necessary owing to conditions in Europe. In the first place, a suitably adapted fuel cycle will have to be devised to cover the period between the start-up of the first station and the construction in Europe of reprocessing and fabrication plants. As regards the core structure, modifications of the axial and radial protection components have been considered with a view to replacing the borated graphite by graphite-steel, thereby achieving economies and also putting an end to the permanent presence of boron in the core. A feasibility study indicates that ceramic materials like Masrock would be very suitable for hot zones for which silicon wool was initially envisaged. The question of the in-service inspection of the core cavity has been studied with a view to permitting the surveillance of most structures. Efforts are being made to achieve even further operational flexibility in the light of conditions in Europe. In view of the special safety regulations and requirements formulated by the responsible national authorities in Europe, particular attention has been paid to the protection of safety components and systems in the reactor. (author)

  9. Sand swimming lizard: sandfish

    Maladen, Ryan D; Kamor, Adam; Goldman, Daniel I

    2009-01-01

    We use high-speed x-ray imaging to reveal how a small (~10cm) desert dwelling lizard, the sandfish (Scincus scincus), swims within a granular medium [1]. On the surface, the lizard uses a standard diagonal gait, but once below the surface, the organism no longer uses limbs for propulsion. Instead it propagates a large amplitude single period sinusoidal traveling wave down its body and tail to propel itself at speeds up to ~1.5 body-length/sec. Motivated by these experiments we study a numerical model of the sandfish as it swims within a validated soft sphere Molecular Dynamics granular media simulation. We use this model as a tool to understand dynamics like flow fields and forces generated as the animal swims within the granular media. [1] Maladen, R.D. and Ding, Y. and Li, C. and Goldman, D.I., Undulatory Swimming in Sand: Subsurface Locomotion of the Sandfish Lizard, Science, 325, 314, 2009

  10. Comparative genomics reveals adaptations of a halotolerant thaumarchaeon in the interfaces of brine pools in the Red Sea

    Ngugi, David

    2014-08-08

    The bottom of the Red Sea harbors over 25 deep hypersaline anoxic basins that are geochemically distinct and characterized by vertical gradients of extreme physicochemical conditions. Because of strong changes in density, particulate and microbial debris get entrapped in the brine-seawater interface (BSI), resulting in increased dissolved organic carbon, reduced dissolved oxygen toward the brines and enhanced microbial activities in the BSI. These features coupled with the deep-sea prevalence of ammonia-oxidizing archaea (AOA) in the global ocean make the BSI a suitable environment for studying the osmotic adaptations and ecology of these important players in the marine nitrogen cycle. Using phylogenomic-based approaches, we show that the local archaeal community of five different BSI habitats (with up to 18.2% salinity) is composed mostly of a single, highly abundant Nitrosopumilus-like phylotype that is phylogenetically distinct from the bathypelagic thaumarchaea; ammonia-oxidizing bacteria were absent. The composite genome of this novel Nitrosopumilus-like subpopulation (RSA3) co-assembled from multiple single-cell amplified genomes (SAGs) from one such BSI habitat further revealed that it shares ∼54% of its predicted genomic inventory with sequenced Nitrosopumilus species. RSA3 also carries several, albeit variable gene sets that further illuminate the phylogenetic diversity and metabolic plasticity of this genus. Specifically, it encodes for a putative proline-glutamate \\'switch\\' with a potential role in osmotolerance and indirect impact on carbon and energy flows. Metagenomic fragment recruitment analyses against the composite RSA3 genome, Nitrosopumilus maritimus, and SAGs of mesopelagic thaumarchaea also reiterate the divergence of the BSI genotypes from other AOA.

  11. Simulation of decay heat removal by natural convection in a pool type fast reactor model-ramona-with coupled 1D/2D thermal hydraulic code system

    Kasinathan, N.; Rajakumar, A.; Vaidyanathan, G.; Chetal, S.C. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

    1995-09-01

    Post shutdown decay heat removal is an important safety requirement in any nuclear system. In order to improve the reliability of this function, Liquid metal (sodium) cooled fast breeder reactors (LMFBR) are equipped with redundant hot pool dipped immersion coolers connected to natural draught air cooled heat exchangers through intermediate sodium circuits. During decay heat removal, flow through the core, immersion cooler primary side and in the intermediate sodium circuits are also through natural convection. In order to establish the viability and validate computer codes used in making predictions, a 1:20 scale experimental model called RAMONA with water as coolant has been built and experimental simulation of decay heat removal situation has been performed at KfK Karlsruhe. Results of two such experiments have been compiled and published as benchmarks. This paper brings out the results of the numerical simulation of one of the benchmark case through a 1D/2D coupled code system, DHDYN-1D/THYC-2D and the salient features of the comparisons. Brief description of the formulations of the codes are also included.

  12. Electromechanical drive for a reactor control system

    The invention is related to control systems of nuclear researche swimming pool-type reactors. The presented electromechanical drive for a nuclear reactor control system consists of an electromagnetic grip of control element with magnet power supply cable, drum and flexible element, e.g., wire rope. Two branches of the rope which are separated from the electromagnet to the core and the drum form the closed loop. To decrease the dimensions of the drive, the magnet power supply cable serves as a loop flexible element which goes from the electromagnet to the core. For a particular reactor the drive, made according to the invention is 100 mm shorter and 20 mm narrower as compared with the known one, and that is rather significant in cases when a drive is to be installed directly on a control system channel

  13. Pakistan research reactor-1 and its upgradation

    In this article the author describes the procedure of renovation and upgradation of a swimming pool type Pakistan Research Reactor-1 (PARR-1) installed at PINSTECH. The reactor originally designed for a thermal power of 5 MW using highly enriched uranium as has been upgraded 10 MW with low enriched uranium as fuel. All the required safety precaution has been also modified with the new requirements. The cooling system of PARR-1 was modified to meet the requirements of upgraded power of 10 MW. In order to ensure safety for upgraded PARR-1 and to bring the reactor the current safety standards, some additional safety systems have been provided. An emergency core cooling system ECCS has been installed to remove core decay heat in case of loss of coolant accident (LOCA). (A.B.)

  14. An Account of Oak Ridge National Laboratory's Thirteen Research Reactors

    The Oak Ridge National Laboratory has built and operated 13 nuclear reactors in its 66-year history. The first was the graphite reactor, the world's first operational nuclear reactor, which served as a plutonium production pilot plant during World War II. It was followed by two aqueous-homogeneous reactors and two red-hot molten-salt reactors that were parts of power-reactor development programs and by eight others designed for research and radioisotope production. One of the eight was an all-metal fast burst reactor used for health physics studies. All of the others were light-water cooled and moderated, including the famous swimming-pool reactor that was copied dozens of times around the world. Two of the reactors were hoisted 200 feet into the air to study the shielding needs of proposed nuclear-powered aircraft. The final reactor, and the only one still operating today, is the High Flux Isotope Reactor (HFIR) that was built particularly for the production of californium and other heavy elements. With the world's highest flux and recent upgrades that include the addition of a cold neutron source, the 44-year-old HFIR continues to be a valuable tool for research and isotope production, attracting some 500 scientific visitors and guests to Oak Ridge each year. This report describes all of the reactors and their histories.

  15. HTR research and development in Austria - 1986-1987 progress report

    Though Austria has no national programme in the field of GCR's due to Austria's participation in the former OECD Dragon Project, a considerable amount of R and D work has been performed and is still going on in the following areas related to high-temperature gas cooled reactors (HTGR): high-temperature reactor fuel, high-temperature structural materials and high-temperature helium testing/prestressed concrete pressure vessel. The report summarizes the work performed since the 6th IWGGCR Meeting in Hamm, 1985. 8 refs

  16. Biological Significance of Photoreceptor Photocycle Length: VIVID Photocycle Governs the Dynamic VIVID-White Collar Complex Pool Mediating Photo-adaptation and Response to Changes in Light Intensity.

    Arko Dasgupta

    2015-05-01

    Full Text Available Most organisms on earth sense light through the use of chromophore-bearing photoreceptive proteins with distinct and characteristic photocycle lengths, yet the biological significance of this adduct decay length is neither understood nor has been tested. In the filamentous fungus Neurospora crassa VIVID (VVD is a critical player in the process of photoadaptation, the attenuation of light-induced responses and the ability to maintain photosensitivity in response to changing light intensities. Detailed in vitro analysis of the photochemistry of the blue light sensing, FAD binding, LOV domain of VVD has revealed residues around the site of photo-adduct formation that influence the stability of the adduct state (light state, that is, altering the photocycle length. We have examined the biological significance of VVD photocycle length to photoadaptation and report that a double substitution mutant (vvdI74VI85V, previously shown to have a very fast light to dark state reversion in vitro, shows significantly reduced interaction with the White Collar Complex (WCC resulting in a substantial photoadaptation defect. This reduced interaction impacts photoreceptor transcription factor WHITE COLLAR-1 (WC-1 protein stability when N. crassa is exposed to light: The fast-reverting mutant VVD is unable to form a dynamic VVD-WCC pool of the size required for photoadaptation as assayed both by attenuation of gene expression and the ability to respond to increasing light intensity. Additionally, transcription of the clock gene frequency (frq is sensitive to changing light intensity in a wild-type strain but not in the fast photo-reversion mutant indicating that the establishment of this dynamic VVD-WCC pool is essential in general photobiology and circadian biology. Thus, VVD photocycle length appears sculpted to establish a VVD-WCC reservoir of sufficient size to sustain photoadaptation while maintaining sensitivity to changing light intensity. The great diversity

  17. Vernal Pools

    California Department of Resources — This is a polygon layer representing existing vernal pool complexes in California's Central Valley, as identified and mapped by Dr. Robert F. Holland. The purpose...

  18. Neutron detection in an atomic reactor core using semi-conductors

    In this paper, the first part describes the principle of nuclear particle detection by means of semiconductor diodes and the general application of these. The second part describes fabrication of the device used to estimate thermic neutron fluxes in core of a swimming pool type reactor. The useful volume (2.9 mm thickness) is in the light water moderator, between combustible elements plates. The results, principally obtained in the core of Siloette reactor at the 'Centre d'Etudes Nucleaires de Grenoble' at low power, are mentioned in the third part. Flux maps have been set and comparison between converter's products: Bore 10, Lithium 6, Uranium 235 is made. (author)

  19. Austria; Recent Developments and Issues

    International Monetary Fund

    1995-01-01

    This report describes recent developments and issues in Austria. The report discusses the structural features of the Austrian labor market. Two features—the relative importance of foreign labor supply, and the comparatively low labor force participation of certain groups—are analyzed in detail. The historical structure of the Austrian balance of payments is discussed, and the developments in 1994 are analyzed. The report also examines the Austrian tourism industry and its underlying probl...

  20. Real Estate Inheritance in Austria

    Pirmin Fessler; Peter Mooslechner; Martin Schürz

    2010-01-01

    As real estate inheritances are an important component of Austrian households’ assets, they are relevant for monetary policymaking and for the maintenance of financial stability. 20% of Austrian households have inherited real estate wealth, with some 2% of all households accounting for around 40% of the overall volume of real estate inheritances in Austria. In aggregate, real estate inheritances constitute up to 23% of households’ total real estate wealth. Households which have inherited diff...

  1. Ozone promoters situation in Austria

    An analysis of the main ozone promoters (volatile organic compounds (NMVOC), NOx and CO) emissions in Austria was performed and the results were compared against international and national limits (Austrian ozone law). This analysis covered the trends in the years 1990-2002. 204,000 tons of nitrogen oxides (NOx), 193,000 tons of volatile organic compounds (NMVOC) and 812,000 tons of carbon monoxide (CO) were emitted in 2002. 6 figs. (nevyjel)

  2. CREATINE SUPPLEMENTATION AND SWIM PERFORMANCE: A BRIEF REVIEW

    Melissa J. Hopwood

    2006-03-01

    Full Text Available Nutritional supplements are popular among athletes participating in a wide variety of sports. Creatine is one of the most commonly used dietary supplements, as it has been shown to be beneficial in improving performance during repeated bouts of high-intensity anaerobic activity. This review examines the specific effects of creatine supplementation on swimming performance, and considers the effects of creatine supplementation on various measures of power development in this population. Research performed on the effect of creatine supplementation on swimming performance indicates that whilst creatine supplementation is ineffective in improving performance during a single sprint swim, dietary creatine supplementation may benefit repeated interval swim set performance. Considering the relationship between sprint swimming performance and measurements of power, the effect of creatine supplementation on power development in swimmers has also been examined. When measured on a swim bench ergometer, power development does show some improvement following a creatine supplementation regime. How this improvement in power output transfers to performance in the pool is uncertain. Although some evidence exists to suggest a gender effect on the performance improvements seen in swimmers following creatine supplementation, the majority of research indicates that male and female swimmers respond equally to supplementation. A major limitation to previous research is the lack of consideration given to the possible stroke dependant effect of creatine supplementation on swimming performance. The majority of the research conducted to date has involved examination of the freestyle swimming stroke only. The potential for performance improvements in the breaststroke and butterfly swimming strokes is discussed, with regards to the biomechanical differences and differences in efficiency between these strokes and freestyle

  3. Optimization of reactor network design problem using Jumping Gene Adaptation of Differential Evolution

    Gujarathi, Ashish M.; Purohit, S.; Srikanth, B.

    2015-06-01

    Detailed working principle of jumping gene adaptation of differential evolution (DE-JGa) is presented. The performance of the DE-JGa algorithm is compared with the performance of differential evolution (DE) and modified DE (MDE) by applying these algorithms on industrial problems. In this study Reactor network design (RND) problem is solved using DE, MDE, and DE-JGa algorithms: These industrial processes are highly nonlinear and complex with reference to optimal operating conditions with many equality and inequality constraints. Extensive computational comparisons have been made for all the chemical engineering problems considered. The results obtained in the present study show that DE-JGa algorithm outperforms the other algorithms (DE and MDE). Several comparisons are made among the algorithms with regard to the number of function evaluations (NFE)/CPU- time required to find the global optimum. The standard deviation and the variance values obtained using DE-JGa, DE and MDE algorithms also show that the DE-JGa algorithm gives consistent set of results for the majority of the test problems and the industrial real world problems.

  4. Renewable energy in Lower Austria

    The year 2004 was very successful for renewable energy in Lower Austria and more biomass district heating plants, biomass power plants, biogas plants and windmills were built then the years before. Renewable energy has become an important factor in energy supply. About 7% of electricity in Lower Austria is produced by wind, biomass and biogas. Investments of about 185 million Euro were effected by supports and are also important for the economy. There are 240 biomass district heating plants with 282 MW thermal output in operation. The fuel need of 1,4 million cubic meters wood and 15.000 tons straw per year safeguards jobs in rural areas. After the decision of the Ecological Electricity Act 2002 a biogas campaign started in Lower Austria. Biogas plants for renewable resources and agricultural products are supported by subsidies and regulated prices for renewable electricity which is fed into the national grid. There was also a considerable increase of windmills in the year 2004 and today 197 plants with 251 MW output are in operation. (author)

  5. [Epidemiology of obesity in Austria].

    Dorner, Thomas E

    2016-03-01

    The purpose of this article was to compile all existing data regarding the prevalence of obesity in Austria in all age groups, and to perform additional analyses. Prevalence of obesity in the adult Austrian population varies between 8.3 and 19.9% in men, and 9.0 and 19.8% in women with increasing trends over time. Prevalence of obesity in children and adolescents in Austria varies between 3.1 and 9.0% in boys and between 2.2 and 7.3% in girls. Factors associated with obesity include higher age, lower educational level, profession, migration background, living in eastern parts of Austria, lack of social support, and psycho-social pressure. In women, socio-economic parameters are stronger associated with obesity compared to men. Obesity is associated with hypertension, diabetes mellitus, osteoarthritis, and low back pain, and deteriorated quality of live, in both sexes, and in men additionally with a history of heart attack, and in women additionally with anxiety/depression. PMID:26650060

  6. Can two spheres swim?

    Klotsa, Daphne; Hill, Richard J A; Bowley, Roger M; Swift, Michael R

    2015-01-01

    We describe experiments and simulations demonstrating the propulsion of a neutrally-buoyant swimmer that consists of a pair of spheres attached by a spring, placed in a vibrating fluid. The vibration of the fluid induces relative motion of the spheres which, for sufficiently large amplitudes, can lead to motion of the center of mass of the two spheres. We find that the swimming speed obtained from both experiment and simulation agree and collapse onto a single curve if plotted as a function of the streaming Reynolds number, suggesting that the propulsion is related to streaming flows. There appears to be a critical onset value of the streaming Reynolds number for swimming to occur. The mechanism for swimming is traced to a jet of fluid generated by the relative motion of the spheres.

  7. Ilves urges closer ties while in Austria / Ella Karapetyan

    Karapetyan, Ella

    2010-01-01

    President Toomas Hendrik Ilvese ametlik visiit Austria Vabariiki 22.11.2010 - 24.11.2010. Eesti riigipea pidas kõne Austria Majanduskojas Eesti-Austria majandusfoorumil, kohtus Alam-Austria Liidumaa parlamendi presidendi Hanz Penz'i ning Austria presidendi Heinz Fischeriga. Presidentide kohtumisel räägiti EL-i laienemispoliitikast, energiajulgeoleku probleemidest, Euroopa naabruspoliitikast ja idapartnerlusest

  8. Evaluation of the aptitude for the service of the pool of the TRIGA Mark III reactor of the National Institute of Nuclear Research of Mexico; Evaluacion de la aptitud para el servicio de la piscina del reactor TRIGA Mark III del Instituto Nacional de Investigaciones Nucleares de Mexico

    Merino C, J.; Gachuz M, M.; Diaz S, A.; Arganis J, C.; Gonzalez R, C.; Nava G, T.; Medina R, M.J. [Departamento de Sintesis y Caracterizacion de Materiales del ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2001-07-01

    This work describes the evaluation of the structural integrity of the pool of the TRIGA Mark III reactor of the National Institute of Nuclear Research of Mexico, which was realized in July 2001, as an element to determine those actions for preventive and corrective maintenance which owner must do it for a safety and efficient operation of the component in the next years. (Author)

  9. Swimming Performance Assessment in Fishes

    Keith B Tierney

    2011-01-01

    Swimming performance tests of fish have been integral to studies of muscle energetics, swimming mechanics, gas exchange, cardiac physiology, disease, pollution, hypoxia and temperature. This paper describes a flexible protocol to assess fish swimming performance using equipment in which water velocity can be controlled. The protocol involves one to several stepped increases in flow speed that are intended to cause fish to fatigue. Step speeds and their duration can be set to capture swimming ...

  10. The pool chlorine hypothesis and asthma among boys.

    Cotter, A

    2012-01-31

    Swimming pool sanitation has largely been concerned with the microbiological quality of pool water, which is normally treated using a number of chlorine products. Recent studies have pointed to the potential hazards of chlorine by-products to the respiratory epithelium, particularly in indoor, poorly ventilated, pools. The aim of our study was to elucidate whether chronic exposure to indoor chlorinated swimming pools was associated with an increased likelihood of the development of asthma in boys. METHODS: The subjects were boys aged between 6 and 12 years. Data was collected by means of parental responses to a standardized asthma questionnaire (ISAAC: International Study of Asthma and Allergies in Childhood), supplemented with additional questions regarding frequency of attendance, number of years attendance, whether the child is a swimming team member. The questionnaire return rate was 71\\/% (n = 121). 23 boys were excluded on the basis that they had asthma before they started swimming (n = 97). There was a significant association between number of years a boy had been swimming and the likelihood of wheezing in the last 12 months (p = 0.009; OR = 1.351; 95% CI = 1.077-1.693) and diagnosed asthma (p = 0.046; OR = 1.299; 95% CI = 1.004-1.506). The greater the number the number of years a boy had been attending an indoor, chlorinated pool, the greater the likelihood of wheezing in the last 12 months or "had asthma". Age, parental smoking habits and being a swimming team member had no association with any of the asthma variables examined. Swimming pool attendance may be a risk factor in asthma in boys.

  11. Republic of Austria. Country profile.

    Newcomb, L C

    1985-07-01

    A summary description of Austria's demographic situation, economic conditions, labor force characteristics, housing conditions, household characteristics, and marriage patterns is provided. Austria, the former center of the Hapsburg Empire, covers 32,375 square miles and is divided into 9 provinces, including Vienna, the federal capital. Austria's population increased from 6.9 million in 1950 to 7.6 million in 1980. Since 1980 it declined slightly and in 1985 it was estimated to be 7,487,000. Between 1961-81, the industrial, western region of the country grew more rapidly than the predominantly rural eastern section of the country. Vienna, the largest city in the country, experienced a decline in population size from 1.9 million to 1.5 million since 1923. Part of the decline was due to the annihilation of the city's Jewish population in 1938. Austria has a lower urban population (56%) than most other industrialized countries. This low rate reflects the availability of tourist related jobs in the rural areas. 98% of the population is Austrian, the official language is German, and most of the inhabitants are Roman Catholic. Due to the homogeneity of the population, the country has few religious and racial problems; however, a recent study indicated that about 1/2 of the population has anti-Semetic attitudes. Life expectancy is 69 years for men and 76 years for women. Austria's population is aging. Currently, 18% of the population is under 15 years of age, and 14% is 65 years of age or older. Births are expected to increase slightly until the end of the 1900s and then decline slightly. Austrians place a high value on children and family life. Between 1978-82 the marriage rate increased from 4.5/1000 to 4.8/1000, and the median age at marriage increased from 22.4-23.0 years for women and from 25.6-25.8 years for men. The number of divorces/year increased from 11,168-14.298 between 1976-82. Currently, there are 2,767,000 households, and the average household size is 2

  12. Self-adaptive treatment of time dependent nonlinear nonhomogeneous radial heat flow in reactor components with boundary element method

    The basic principles of self-adaptive algorithm for treatment of transient nonlinear nonhomogeneous radial heat flow, based on direct Boundary Element method formulation, are presented. The indicators of discretization error are developed, together with binary-tree strategy for manipulation with time domain mesh, assuring automatic optimisation of calculation procedure with respect to predetermined error. The developed method is particularly suitable for use in a spectrum of extremely nonlinear cases, occurring in thermal analyses of reactor components.(author)

  13. Reactor building

    The present invention concerns a structure of ABWR-type reactor buildings, which can increase the capacity of a spent fuel storage area at a low cost and improved earthquake proofness. In the reactor building, the floor of a spent fuel pool is made flat, and a depth of the pool water satisfying requirement for shielding is ensured. In addition, a depth of pool water is also maintained for a equipment provisionally storing pool for storing spent fuels, and a capacity for a spent fuel storage area is increased by utilizing surplus space of the equipment provisionally storing pool. Since the flattened floor of the spent fuel pool is flushed with the floor of the equipment provisionally storing pool, transfer of horizontal loads applied to the building upon occurrence of earthquakes is made smooth, to improve earthquake proofness of the building. (T.M.)

  14. Swimming stadium in Prague

    Svobodová, Markéta

    Prague: Prostor - architektura, interiér, design, 2012 - (Švácha, R.), s. 208-211 ISBN 978-80-87064-09-2 Institutional support: RVO:68378033 Keywords : swimming stadium * Richard Ferdinand Podzemný * Gustav Kuchař Subject RIV: AL - Art, Architecture, Cultural Heritage

  15. Independent Confirmatory Survey Report for the University of Arizona Nuclear Reactor Laboratory, Tucson, Arizona DCN:2051-SR-01-0

    The University of Arizona (University) research reactor is a TRIGA swimming pool type reactor designed by General Atomics and constructed at the University in 1958. The reactor first went into operation in December of 1958 under U.S. Nuclear Regulatory Commission (NRC) license R-52 until final shut down on May 18, 2010. Initial site characterization activities were conducted in February 2009 during ongoing reactor operations to assess the radiological status of the Nuclear Reactor Laboratory (NRL) excluding the reactor tank, associated components, and operating systems. Additional post-shutdown characterization activities were performed to complete characterization activities as well as verify assumptions made in the Decommissioning Plan (DP) that were based on a separate activation analysis (ESI 2009 and WMG 2009). Final status survey (FSS) activities began shortly after the issuance of the FSS plan in May 2011. The contractor completed measurement and sampling activities during the week of August 29, 2011.

  16. Austria: The INIS Austria Centre 1970-2015

    This article spotlights Austrian people and institutions that have influenced the fortunes of INIS and the INIS Centre in Austria. The work of two Austrians had a lasting influence on INIS. The first person, Ms Elisabeth Ruckenbauer, was Head of the INIS Bibliographic Control Unit at the start of INIS. She was responsible for the development and implementation of the INIS bibliographic description rules (INIS Reference Series IAEA-INIS-01 and -02). The second person having a lasting influence on INIS was Mr Alexander Nevyjel. He was Austrian INIS Liaison Officer from 1983 –2002, and Head of the INIS Subject Control Unit until 2011. During his second term of office, he developed, together with the Swiss company Convera, the Computer Assisted Indexing Software (CAI). The aim of the project was to optimize indexing. The implementation of CAI in 2004 resulted in an increase of input to the INIS database; from around 60 000 records per year to over 100 000 records per year. We are proud that Mr Nevyjel is still an active member of the INIS Austria Center and that he continues to offer his experience and expertise. The Austrian INIS Centre has resided at two scientific institutions: Seibersdorf and the Austrian Central Library for Physics and Chemistry Library, each having a specific relationship with the IAEA and INIS

  17. Sewage sludge disposal in Austria

    Sewage systems serve about 70% of the Austrian population, producing 6 million m3 of sewage sludge per year with a dry matter content of 4-5%. At present about 52% of this sludge is disposed of in land fills, 33% is incinerated, and only about 15 % is used in agriculture. Although agricultural utilization is becoming increasingly important, several problems, especially those related to public opinion, need to be resolved before increased use will be possible. In this paper, wastewater treatment and sewage-sludge production in Austria, and problems associated with sludge disposal are discussed. (author)

  18. Pooling Resources

    DING WENLEI

    2010-01-01

    @@ While the 1997 Asian financial crisis gave birth to the Chiang Mai Initiative,a foreign currency reserve pool to address short-term liquidity difficulties in the region,the 2008global financial crisis promoted Asian political leaders,bankers and scholars to seek closer regional financial cooperation based on the initiative's framework.

  19. Saturated Adaptive Output-Feedback Power-Level Control for Modular High Temperature Gas-Cooled Reactors

    Zhe Dong

    2014-11-01

    Full Text Available Small modular reactors (SMRs are those nuclear fission reactors with electrical output powers of less than 300 MWe. Due to its inherent safety features, the modular high temperature gas-cooled reactor (MHTGR has been seen as one of the best candidates for building SMR-based nuclear plants with high safety-level and economical competitive power. Power-level control is crucial in providing grid-appropriation for all types of SMRs. Usually, there exists nonlinearity, parameter uncertainty and control input saturation in the SMR-based plant dynamics. Motivated by this, a novel saturated adaptive output-feedback power-level control of the MHTGR is proposed in this paper. This newly-built control law has the virtues of having relatively neat form, of being strong adaptive to parameter uncertainty and of being able to compensate control input saturation, which are given by constructing Lyapunov functions based upon the shifted-ectropies of neutron kinetics and reactor thermal-hydraulics, giving an online tuning algorithm for the controller parameters and proposing a control input saturation compensator respectively. It is proved theoretically that input-to-state stability (ISS can be guaranteed for the corresponding closed-loop system. In order to verify the theoretical results, this new control strategy is then applied to the large-range power maneuvering control for the MHTGR of the HTR-PM plant. Numerical simulation results show not only the relationship between regulating performance and control input saturation bound but also the feasibility of applying this saturated adaptive control law practically.

  20. Strengthening DiD in Emergency Preparedness and Response by Pre-Establishing Tools and Criteria for the Effective Protection of the Public During a Severe Emergency at a Light Water Reactor or its Spent Fuel Pool

    Defence in depth can be divided into two parts: first, to prevent accidents and, second, if prevention fails, to limit their consequences and prevent any evolution to more serious conditions. This paper will cover the second part, by providing tools and criteria to be used during a severe emergency to limit the consequences to the public from a severe accident. Severe radiation-induced consequences among the public off-site are only possible if there is significant damage to fuel in the reactor core or spent fuel pools. Consequently, the tools and criteria have been specifically developed for individuals responsible for making and for acting on decisions to protect the public in the event of an emergency involving actual or projected severe damage to the fuel in the reactor core or spent fuel pool of a light water reactor (LWR). These tools and criteria, developed by the IAEA’s Incident and Emergency Centre (IEC), will facilitate the implementation of the ‘Emergency Response’ defence in depth concept. (author)

  1. La autopista de Viena Austria

    Editorial, Equipo

    1979-10-01

    Full Text Available The elevated stretch of the motorway crossing the city of Vienna in a North-South direction is the largest bridge in Austria. The bridge consists of a central span, the corresponding access ramps at the ends and a junction with a district highway having six separate roadways. The design and construction of the bridge was based on the principle of using the maximum amount of prefabricated parts in order to, on the one hand, achieve a higher constructive rationalization, and on the other, minimize erection time. Owing to its being inside the city, the bridge has been fitted with adequate lighting and runoff water disposal systems.

    El tramo volado de la autopista, que cruza Viena de norte a sur, constituye el puente más grande de toda Austria. Dicho puente consta de un tramo central, las correspondientes rampas de acceso en los extremos, y un nudo de enlace con la carretera comarcal compuesto por seis calzadas distintas. En su diseño y realización se procuró utilizar el mayor número posible de elementos prefabricados para, por una parte, permitir una construcción más racionalizada y, por otra, minimizar los tiempos de ejecución. Se ha dotado a toda la obra, por estar dentro de la ciudad, de unos adecuados sistemas de iluminación y evacuación de las aguas superficiales.

  2. Mining in Austria in 1992

    The mineral production of Austria, in 1992 - as far as under the supervision of the Austrian Mine Inspectorate, run up to about 50 million t of solid minerals, 1.2 million t of oil and 1.4 billion m3 of natural gas. 88% of the solid minerals comprised industrial minerals, 4% metals, 4% salt and 4% coal. The solid minerals were produced by 352 open pits and 15 underground mines. 3 of the operations worked both on surface and underground and one mine is a well field operation. In total around 8000 people were employed in the field of mining and mineral processing. The minerals produced represent a value of about 15 billion Austrian Schillings (about 1.25 billion US $), the major part being the industrial minerals sector with a share of 7 billion Austrian Schillings and oil and gas with around 4 billion Austrian Schillings. The industrial minerals sector does not play only in Austrian an important role, but contributes also remarkably to the world production. This comprises mainly magnesite, talc, kaolin and graphite where Austria produces more than 1% of the world production. Summarizing, it can be said that the future of the Austrian mining sector is quite prosperous, perhaps better than in some other traditional mining countries in Europe, where the change from the coal and base metals sector towards the industrial sector has not come so far. (orig.)

  3. Second messenger-mediated adjustment of bacterial swimming velocity.

    Boehm, Alex; Kaiser, Matthias; Li, Hui; Spangler, Christian; Kasper, Christoph Alexander; Ackermann, Martin; Kaever, Volkhard; Sourjik, Victor; Roth, Volker; Jenal, Urs

    2010-04-01

    Bacteria swim by means of rotating flagella that are powered by ion influx through membrane-spanning motor complexes. Escherichia coli and related species harness a chemosensory and signal transduction machinery that governs the direction of flagellar rotation and allows them to navigate in chemical gradients. Here, we show that Escherichia coli can also fine-tune its swimming speed with the help of a molecular brake (YcgR) that, upon binding of the nucleotide second messenger cyclic di-GMP, interacts with the motor protein MotA to curb flagellar motor output. Swimming velocity is controlled by the synergistic action of at least five signaling proteins that adjust the cellular concentration of cyclic di-GMP. Activation of this network and the resulting deceleration coincide with nutrient depletion and might represent an adaptation to starvation. These experiments demonstrate that bacteria can modulate flagellar motor output and thus swimming velocity in response to environmental cues. PMID:20303158

  4. Respiratory Function and Changes in Lung Epithelium Biomarkers after a Short-Training Intervention in Chlorinated vs. Ozone Indoor Pools

    Álvaro Fernández-Luna; Leonor Gallardo; María Plaza-Carmona; Jorge García-Unanue; Javier Sánchez-Sánchez; José Luis Felipe; Pablo Burillo; Ignacio Ara

    2013-01-01

    BACKGROUND: Swimming in indoor pools treated with combined chemical treatments (e.g. ozone) may reduce direct exposure to disinfection byproducts and thus have less negative effects on respiratory function compared to chlorinated pools. The aim of this study is to analyze the effects of a short-term training intervention on respiratory function and lung epithelial damage in adults exercising in indoor swimming pool waters treated with different disinfection methods (chlorine vs. ozone with br...

  5. Mixing by Swimming Algae

    Guasto, Jeffrey S; Gollub, J P; Pesci, Adriana I; Goldstein, Raymond E

    2009-01-01

    In this fluid dynamics video, we demonstrate the microscale mixing enhancement of passive tracer particles in suspensions of swimming microalgae, Chlamydomonas reinhardtii. These biflagellated, single-celled eukaryotes (10 micron diameter) swim with a "breaststroke" pulling motion of their flagella at speeds of about 100 microns/s and exhibit heterogeneous trajectory shapes. Fluorescent tracer particles (2 micron diameter) allowed us to quantify the enhanced mixing caused by the swimmers, which is relevant to suspension feeding and biogenic mixing. Without swimmers present, tracer particles diffuse slowly due solely to Brownian motion. As the swimmer concentration is increased, the probability density functions (PDFs) of tracer displacements develop strong exponential tails, and the Gaussian core broadens. High-speed imaging (500 Hz) of tracer-swimmer interactions demonstrates the importance of flagellar beating in creating oscillatory flows that exceed Brownian motion out to about 5 cell radii from the swimm...

  6. Stirring by swimming bodies

    We consider the stirring of an inviscid fluid caused by the locomotion of bodies through it. The swimmers are approximated by non-interacting cylinders or spheres moving steadily along straight lines. We find the displacement of fluid particles caused by the nearby passage of a swimmer as a function of an impact parameter. We use this to compute the effective diffusion coefficient from the random walk of a fluid particle under the influence of a distribution of swimming bodies. We compare with the results of simulations. For typical sizes, densities and swimming velocities of schools of krill, the effective diffusivity in this model is five times the thermal diffusivity. However, we estimate that viscosity increases this value by two orders of magnitude.

  7. Austria

    Leixnering, Stephan; Schikowitz, Andrea; Meyer, Renate E.

    2016-01-01

    The Austrian COCOPS findings confirm the ongoing relevance of the traditional legalistic public sector norms and values. However, this traditional administrative culture is today supplemented with managerialistic and network-oriented ideas and orientations. Combining a focus on results with process...

  8. Computer codes used during upgrading activities at MINT TRIGA reactor

    Mohammad Suhaimi Kassim; Adnan Bokhari; Mohd. Idris Taib [Malaysian Institute for Nuclear Technology Research, Kajang (Malaysia)

    1999-10-01

    MINT TRIGA Reactor is a 1-MW swimming pool nuclear research reactor commissioned in 1982. In 1993, a project was initiated to upgrade the thermal power to 2 MW. The IAEA assistance was sought to assist the various activities relevant to an upgrading exercise. For neutronics calculations, the IAEA has provided expert assistance to introduce the WIMS code, TRIGAP, and EXTERMINATOR2. For thermal-hydraulics calculations, PARET and RELAP5 were introduced. Shielding codes include ANISN and MERCURE. However, in the middle of 1997, MINT has decided to change the scope of the project to safety upgrading of the MINT Reactor. This paper describes some of the activities carried out during the upgrading process. (author)

  9. performance analysis of radiation level reduction systems for ETRR-2 main pool

    during the operation rectors, fission of the nuclear fuel, neutron activation of structural materials, corrosion products and impurities in reactor coolant water from a radio-nuclide take place. even with the most rigorous controls, some gases, liquid and solid particles escape to the environment. these materials could affect humans and the environment in direct or indirect way . the reactor hall ventilation system is one of the systems, used with the intention, to reduce the quantity of the released radioactive products. the ventilation system used in the egyptian second research reactor ETRR-2, is an example of these ventilation systems . it contains an air curtain in the main pool. in view of radiation effects it would appear that, without hot water layer system, swimming pool reactors can not be operated at higher power levels than about 1 MW [29]. the ETRR-2 contains a hot water layer system ( HWL), in the upper most part of the reactor main pool. in the present study, the role of ETRR-2 reactor hall ventilation system (with an air curtain ) on the release of radioactive products from the reactor has been experimentally studied in normal operating conditions at full power. a model is devolved to describe the reactor hall ventilation system which includes the air curtain effect. the experimental were used to test the model by measuring the activity level of two types of isotopes; activation products and fission products. type (1)isotope is argon-41(Ar41), which is a noble gas having high activity release rate is chosen to represent an activation product. whereas type (2) isotope is iodine-131 (I131), which is a fission product and it has a low activity release rate. it is considered, from radiological point of view as one of the most dangerous radioisotopes. the experimental results has shown that the model is adequate for describing the effect of reactor hall ventilation on the radioactive releases from the reactor. the results of I131, showed a better

  10. Water droplets also swim!

    van der Linden, Marjolein; Izri, Ziane; Michelin, Sébastien; Dauchot, Olivier

    2015-03-01

    Recently there has been a surge of interest in producing artificial swimmers. One possible path is to produce self-propelling droplets in a liquid phase. The self-propulsion often relies on complex mechanisms at the droplet interface, involving chemical reactions and the adsorption-desorption kinetics of the surfactant. Here, we report the spontaneous swimming of droplets in a very simple system: water droplets immersed in an oil-surfactant medium. The swimmers consist of pure water, with no additional chemical species inside: water droplets also swim! The swimming is very robust: the droplets are able to transport cargo such as large colloids, salt crystals, and even cells. In this talk we discuss the origin of the spontaneous motion. Water from the droplet is solubilized by the reverse micellar solution, creating a concentration gradient of swollen reverse micelles around each droplet. By generalizing a recently proposed instability mechanism, we explain how spontaneous motion emerges in this system at sufficiently large Péclet number. Our water droplets in an oil-surfactant medium constitute the first experimental realization of spontaneous motion of isotropic particles driven by this instability mechanism.

  11. About the safety analysis of Istanbul TRIGA Mark II reactor

    The accidents potentially related to the operation of TRIGA Mark-II reactor have been analysed in Safety Analysis Report of ITU Research Reactor, with special consideration being given to site characteristics. The maximum credible accident which can take place in a swimming pool type research reactor - accidental dropping of a fuel element into of the critical reactor core - is considered. In the safety analysis of pool type reactors BORAX accident is also included. The following events are abnormal incidents that should be taken into account: 1. Cladding rupture. 2. Reactivity accident. 3. Loss of coolant accident. Fission product release during an accident is analysed. Even though the possibility is believed to be exceedingly remote, the most unfavourable assumptions are made: the rapid insertion of the total excess' reactivity in the reactor operating at a power less then 1 kW; Coincidence of the reactivity insertion and loss of coolant accident; Cladding rupture occurring at one of the highest power density fuel elements as a consequence; Emergency ventilation system failure, leading to a vanishing filter efficiency. It is shown that, even under this most unfavourable condition, the maximum radiation to which the nearby inhabitants will be subjected, is 3.8 x 10-2 mRem per 1/2 hr. Even in the hypothetical case of the coincidence of four abnormal incidents the resulting radiation dose to the population does not exceed much the magnitude of the permissible dose of the ICRP recommendations

  12. Pool Size Adaptive Adjusting Algorithm Based on Average Time%基于平均时间的线程池尺寸自适应调整算法

    黄智泉; 刘正熙

    2013-01-01

      为了实现自适应调整线程池尺寸,提高并发程序处理的运行速度、改善效率和降低系统的资源开销,提出了一种基于任务平均处理时间的线程池尺寸自适应调整算法。首先研究线程池的一些特征数据以及用户请求的任务时间周期,提出了任务平均处理时间的概念。然后研究了不同任务类型下,任务平均处理时间与线程池的尺寸的相关性,提出了一种自适应调整算法。实验结果表明,该算法能够自适应调整线程池尺寸到适当区域,有效地提高应用程序的整体性能。%To realize adaptive adjusting the thread pool size,improve the operation speed of concurrent processing program,efficiency and reduce the system resource spending,a thread pool size adaptive adjusting algorithm based on task average time is presented. Firstly,some characteristics of the thread pool and the task time period of users request are studied,then the concept of task average processing time is put forward. After that,the correlation between the task average processing time and thread pool size under the different types of tasks is analyzed. A kind of adaptive adjustment algorithm is put forward. The experimental results show that the algorithm can adaptively adjust thread pool size to the appropriate area,effectively improving the overall performance of application program.

  13. Pool scrubbing

    The Source Term Project in the Third Frame Work Programme of the European Union Was conducted under and important joined effort on pool scrubbing research. CIEMAT was the Task Manager of the project and several other organizations participated in it: JRC-Ispra, NNC Limited, RUB-NES and UPM. The project was divided into several tasks. A peer review of the models in the pool scrubbing codes SPARC90 and BUSCA-AUG92 was made, considering the different aspects in the hydrodynamic phenomenology, particle retention and fission product vapor abortions. Several dominant risk accident sequences were analyzed with MAAP, SPARC90 and BUSCA-AUG92 codes, and the predictions were compared. A churn-turbulent model was developed for the hydrodynamic behaviour of the pool. Finally, an experimental programme in the PECA facility of CIEMAT was conducted in order to study the decontamination factor under jet injection regime, and the experimental observations were compared with the SPARC and BUSCA codes. (Author)

  14. Real-Time Attenuation Of Heated Optical Fibers In A Nuclear Reactor

    Partin, Judy K.; Bolstad, Jon O.; Collins, David R.

    1984-03-01

    The Idaho National Engineering Laboratory is actively involved in the development and application of fiberoptic-based sensor technology for use in nuclear reactor research. One such sensor is a minature fiberoptic probe which senses steam-to-water transitions in a high pressure, high temperature coolant circuit.' Hundreds of these probes have been utilized in non-nuclear reactor simulation facilities and efforts are underway to adapt these and other fiberoptic techniques to full-scale nuclear applications. This paper describes work recently completed to characterize fiberoptic attenuation induced by gamma and neutron radiation in a reactor. The specific goal was to make in-situ attenuation measurements of promising waveguide materials during radiation exposure at elevated temperatures characteristic of reactor environments. Testing was done in a swimming-pool-type reactor generating about one kilowatt thermal power and producing fluxes of about 109n/cm2/sec fast neutrons (>1 MEV), 1010 on /cm2/sec thermal neutrons, and dose rates of 6 X 106 rad/hr gamma radiation. Samples of state-of-the-art radiation-resistant waveguides, received from five manufacturers, were tested simultaneously. One set of waveguides was held at 180°C temperature and the other set remained at 20°C. Attenuation was monitored con-tinuously in several spectral bands in the 600-1050 nanometer region. Total reactor exposure time was about ten hours and the change in attenuation at this time for the heated samples was as low as 5 db/km at the longer wavelengths and as high as 3000 db/km at the shorter wavelengths. Attenuation in this range is acceptable for many instrumentation or sensor applications because transmission distances would be relatively short in the radiated region. The annealing effect at elevated temperature was found to be significant for all waveguide samples. A ten-fold decrease in attenuation was observed for one heated sample in comparison with its counterpart at ambient

  15. Keila Tervisekeskus. Ujula = Keila Health Club. Swimming Pool / Ain Padrik

    Padrik, Ain, 1947-

    2001-01-01

    Projekteerija: Arhitektuuribüroo Künnapu & Padrik. Arhitektid Ain Padrik ja Kristi Alamaa, sisearhitekt Sirje Männik. Konstruktsioonid: Jaan Laks, A-Grupp. Ujulas on võistlus- ja lastebassein, suvel on avatud välibassein. 5 ill.: I korruse plaan, ristlõige, vaated

  16. Use of natural gas for swimming facilities: Energy savings and environmental compatibility

    In the last twenty years, natural gas consumption has greatly increased in the civil sector and this trend will be confirmed in the next decade which will have a considerable increase in the domestic Italian distribution and in national supply networks. Swimming centres, particularly those equipped with covered swimming-pools and therefore characterized by continuous operation during the year, have significant energy consumption, with the same volume, compared with other civil users. This is due not only to the particular operating characteristics of the swimming pool but, in most cases, to the little attention payed to running costs and thus to energy savings. Natural gas, as a versatile fuel of good quality, can offer a valid contribution to the limitation of the energy consumption of swimming centres, as well as, to the abatement of air pollution, in particular, if it is employed together with new technologies such as the cogeneration and gas fuelled heat pumps

  17. Adaptation of phytoplankton-degrading microbial communities to thermal reactor effluent in a new cooling reservoir

    In water column and sediment inocula from a nuclear reactor cooling reservoir, natural phytoplankton substrate labeled with 14C was used to determine aerobic and anaerobic mineralization rates for a range of temperatures (25, 40, 55, and 700C) expected during reactor operation. For experiments that were begun during reactor shutdown, aerobic decomposition occurred at temperatures of 0C. After two months of reactor operation, aerobic rates increased substantially at 55 and 700C, although maximum rates were observed at temperatures of ≤ 400C. The temperature range for which maximum anaerobic mineralization (i.e., the sum of CH4 and CO2) was observed was 25 to 400C when the reactor was off, expanding to 25 to 550C during reactor operation. Increased rates of 550C, but not 700C, correlated with an increase in the ratio of cumulative methane to carbon dioxide produced over 21 days. When reduced reactor power lowered the maximum temperature of the reservoir to 420C, aerobic decomposition at 700C was negligible, but remained substantial at 550C. Selection for thermophilic decomposers occurred rapidly in this system in both aerobic and anaerobic communities and did not require prolonged exposure to elevated temperatures

  18. An Account of Oak Ridge National Laboratory's Thirteen Research Reactors

    Rosenthal, Murray Wilford [ORNL

    2009-08-01

    The Oak Ridge National Laboratory has built and operated 13 nuclear reactors in its 66-year history. The first was the graphite reactor, the world's first operational nuclear reactor, which served as a plutonium production pilot plant during World War II. It was followed by two aqueous-homogeneous reactors and two red-hot molten-salt reactors that were parts of power-reactor development programs and by eight others designed for research and radioisotope production. One of the eight was an all-metal fast burst reactor used for health physics studies. All of the others were light-water cooled and moderated, including the famous swimming-pool reactor that was copied dozens of times around the world. Two of the reactors were hoisted 200 feet into the air to study the shielding needs of proposed nuclear-powered aircraft. The final reactor, and the only one still operating today, is the High Flux Isotope Reactor (HFIR) that was built particularly for the production of californium and other heavy elements. With the world's highest flux and recent upgrades that include the addition of a cold neutron source, the 44-year-old HFIR continues to be a valuable tool for research and isotope production, attracting some 500 scientific visitors and guests to Oak Ridge each year. This report describes all of the reactors and their histories.

  19. Current status and ageing management of the Dalat Nuclear Research Reactor

    The Dalat Nuclear Research Reactor (DNRR) is a 500 kW swimming pool type reactor loaded with the Soviet WWR-M2 fuel elements, moderated and cooled by light water. It was reconstructed and upgraded from the former 250 kW TRIGA Mark-II reactor built in 1963. The first criticality of the renovated reactor was in November 1983 and it has been put in regular operation at nominal power since March 1984. The DNRR is operated mainly in continuous runs of 100 hrs every 4 weeks, for radioisotope production, neutron activation analyses and other research purposes. The remaining time is devoted to maintenance work and to short runs for reactor physics studies as well. From its first start-up to the end of 1998, it totaled about 20,000 hrs of operation at nominal power. After ten years of operation, reactor general inspection and refurbishment were implemented in the 1992-1996 period. In April 1994, refueling work was executed with adding of 11 fresh fuel elements to the reactor core. At present, the reactor has been working with 100-fuel element configuration. Corrosion study has been implemented by visual inspection of the reactor pool tank and some other inside components which remain unchanged from the previous TRIGA reactor. The inspections were carried out with the assistance of some experts from other countries. Some visual inspection results have been obtained and the nature of the electrochemical corrosion and related aspects were little by little identified. In this paper, the operation status of the Dalat reactor is presented, and some activities related to the ageing management of the reactor pool tank and its inside components are also discussed. (author)

  20. Mechanisms of temperature-dependent swimming: the importance of physics, physiology and body size in determining protist swimming speed.

    Beveridge, Oliver S; Petchey, Owen L; Humphries, Stuart

    2010-12-15

    Body temperatures and thus physiological rates of poikilothermic organisms are determined by environmental temperature. The power an organism has available for swimming is largely dependent on physiological rates and thus body temperature. However, retarding forces such as drag are contingent on the temperature-dependent physical properties of water and on an organism's size. Consequently, the swimming ability of poikilotherms is highly temperature dependent. The importance of the temperature-dependent physical properties of water (e.g. viscosity) in determining swimming speed is poorly understood. Here we propose a semi-mechanistic model to describe how biological rates, size and the physics of the environment contribute to the temperature dependency of microbial swimming speed. Data on the swimming speed and size of a predatory protist and its protist prey were collected and used to test our model. Data were collected by manipulating both the temperature and the viscosity (independently of temperature) of the organism's environment. Protists were either cultured in their test environment (for several generations) or rapidly exposed to their test environment to assess their ability to adapt or acclimate to treatments. Both biological rates and the physics of the environment were predicted to and observed to contribute to the swimming speed of protists. Body size was not temperature dependent, and protists expressed some ability to acclimate to changes in either temperature or viscosity. Overall, using our parameter estimates and novel model, we are able to suggest that 30 to 40% (depending on species) of the response in swimming speed associated with a reduction in temperature from 20 to 5°C is due to viscosity. Because encounter rates between protist predators and their prey are determined by swimming speed, temperature- and viscosity-dependent swimming speeds are likely to result in temperature- and viscosity-dependent trophic interactions. PMID:21113003