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Sample records for et-r r-1 reactor

  1. An improved slow neutron spectrometer at nuclear research reactor et-r r-1. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Abu El-Ela, M A [Reactor and Neutron Physics, Nuclear Research Center, AEA, Cairo (Egypt)

    1996-03-01

    An improved slow neutron selector has been aligned at channel number 6 of the nuclear research reactor ET-R R-1 Inshas. The flight path is 4 meter. The collimator-rotor-collimator system has the dimensions 0.3 x 2.5 x 70 cm with the rotor diameter 16 cm and 3 slits of 0.3 x 2.5 cm cross section. The rotor rotation rate varies between 600 r.p.m. the counting system has one of the best modern high electronic advanced technology time analyzer with minimum dwell time 2 sec, 8192 channels and a double detector inputs of TTL and NEG NIM standard pulses. The analyzer external triggering signals are of TTL standard type. A special design {sup 3} He detector for time of flight spectrometry has been used in the SNS. The reactor bare thermal neutron spectrum has been successfully measured, to show good agreement with the previous data. 6 figs.

  2. Radioactive inventory in structural materials of ET-R R-1 reactor and its implication on decommissioning.

    Energy Technology Data Exchange (ETDEWEB)

    Elkady, A; Amin, E [National center for nuclear safety and radiation control, atomic energy authority, Cairo, (Egypt)

    1995-10-01

    A plan for decommissioning of ET-R R-1 reactor should include estimation of radioactivity in structural materials. The inventory will help in assessing the radiological consequences decommissioning. Conservative calculations have been made to evaluate the activity of the long lived isotopes which can be produced by neutron activation. The materials which are present in significant quantities in the reactor structural materials are aluminium, cast iron, graphite, ordinary and iron shot concrete. The radioactivity of each component is dependent not only upon the major elements, but also on the concentration of the trace elements. The main radioactive inventory are expected to be from Co-60 and Fe-55 which are present in aluminium as trace elements in larger quantities in other construction materials. 2 figs., 4 tabs.

  3. Experience gained in refurbishing of the ET-R R-1 reactor in Egypt

    Energy Technology Data Exchange (ETDEWEB)

    Khattab, M; Dimitri, F; Chaath, K [Reactor department, nuclear research center atomic energy authority, Cairo, (Egypt)

    1995-10-01

    This paper describes the in-service program and rehabilitation plan of the control, measuring instrumentation and radiation monitoring equipment as well as the computerized safety logic and signaling systems. the in-service program includes reactor core and pressure vessels. Spent fuel tank and primary cooling circuit have been inspected. Current problems and future plan for improving the safety systems are discussed. 10 figs., 1 tab.

  4. Experience gained in refurbishing of the ET-R R-1 reactor in Egypt

    International Nuclear Information System (INIS)

    Khattab, M.; Dimitri, F.; Chaath, K.

    1995-01-01

    This paper describes the in-service program and rehabilitation plan of the control, measuring instrumentation and radiation monitoring equipment as well as the computerized safety logic and signaling systems. the in-service program includes reactor core and pressure vessels. Spent fuel tank and primary cooling circuit have been inspected. Current problems and future plan for improving the safety systems are discussed. 10 figs., 1 tab

  5. Thermal neutron flux distribution in the ET R R-1 reactor core as experimentally measured and theoretically calculated by the code triton

    Energy Technology Data Exchange (ETDEWEB)

    Imam, M [National center for nuclear safety and radiation control, atomic energy authority, Cairo, (Egypt)

    1995-10-01

    Thermal neutron flux distributions that were measured earlier at the ET-R R-1 reactor are compared with those calculated by the three dimensional diffusion code Triton. This comparison was made for the horizontal and vertical flux distributions. The horizontal thermal flux distributions considered in this comparison were along the core diagonals at two planes of different heights from core bottom, where one at a level passing through the control rod at core center and the other at a level below this control rod. In the meantime all the control rods were taken into consideration. The effect of the existence of a water cavity inside the core as well as the influence of the control rods on the thermal flux are illustrated in this work. The vertical thermal flux distributions considered in the comparison were at two positions in core namely; one along the core height the horizontal reactor power distribution along the core height and the horizontal reactor power distribution along the core diagonal as calculated by the code Triton are also given this work. 8 figs., 1 tab.

  6. The optimum operating conditions of the phased double-rotor facility at the et-R R-1 reactor. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Naguib, K; Habib, N; Kilany, M; Adib, M [Reactor and Neutron Physics Department, Nuclear Research Center, AEA., Cairo (Egypt); Wahba, M [Dept. of Engineering Physics and Mathematics, Faculty of Engineering, Ain Shams University, Cairo (Egypt)

    1996-03-01

    The pulsed neutron polyenergetic thermal beam at ET-R R-1 is produced by a phased double-rotor facility. One of the rotors has two diametrically opposite curved slots, while the second is designed to operate as a rotating collimator, the dimensions of the phased rotating collimator are selected to match the curved slot rotor. The calculated collimator transmissions at different operating conditions are found to be in good agreement with the experimental ones. The optimum operating conditions of double-rotor facility are deduced. The calculations were carried out using a computer programme RCOL. The RCOL was designed in Fortran-77 to operate on PCs. 6 figs.

  7. The optimum operating conditions of the phased double-rotor facility at the et-R R-1 reactor. Vol. 2

    International Nuclear Information System (INIS)

    Naguib, K.; Habib, N.; Kilany, M.; Adib, M.; Wahba, M.

    1996-01-01

    The pulsed neutron polyenergetic thermal beam at ET-R R-1 is produced by a phased double-rotor facility. One of the rotors has two diametrically opposite curved slots, while the second is designed to operate as a rotating collimator, the dimensions of the phased rotating collimator are selected to match the curved slot rotor. The calculated collimator transmissions at different operating conditions are found to be in good agreement with the experimental ones. The optimum operating conditions of double-rotor facility are deduced. The calculations were carried out using a computer programme RCOL. The RCOL was designed in Fortran-77 to operate on PCs. 6 figs

  8. Decommissioning and decontrolling the R1-reactor

    International Nuclear Information System (INIS)

    Bergman, C.; Holmberg, B.T.

    1985-01-01

    Sweden's first nuclear reactor - the research reactor R1 - situated in bedrock under the Royal Technical Institute of Stockholm, has in the period 1981-1983 been subject to a complete decommissioning. The National Institute for Radiation Protection has followed the work in detail, and has after the completion of the decommissioning performed measurements of radioactivity on site. The report gives an account of the work the Institute has done in preparation for- and during decommissioning and specifically report on the measurements for classification of the local as free for non-nuclear use. (aa)

  9. Irradiation routine in the IPR-R1 Triga reactor

    International Nuclear Information System (INIS)

    Maretti Junior, F.

    1980-01-01

    Information about irradiations in the IPR-R1 TRIGA reactor and procedures necessary for radioisotope solicitation are presented All procedures necessary for asking irradiation in the reactor, shielding types, norms of terrestrial and aerial expeditions, payment conditions, and catalogue of disposable isotopes with their respective saturation activities are described. (M.C.K.)

  10. IEA-R1 reactor - Spent fuel management

    International Nuclear Information System (INIS)

    Mattos, J.R.L. De

    1996-01-01

    Brazil currently has one Swimming Pool Research Reactor (IEA-R1) at the Instituto de Pesquisas Energeticas e Nucleares - Sao Paulo. The spent fuel produced is stored both at the Reactor Pool Storage Compartment and at the Dry Well System. The present situation and future plans for spent fuel storage are described. (author). 3 refs, 2 figs, 2 tabs

  11. Electrical system regulations of the IEA-R1 reactor

    International Nuclear Information System (INIS)

    Mello, Jose Roberto de; Madi Filho, Tufic

    2013-01-01

    The IEA-R1 reactor of the Nuclear and Energy Research Institute (IPEN-CNEN/SP), is a research reactor open pool type, designed and built by the U.S. firm Babcock and Wilcox, having, as coolant and moderator, deionized light water and beryllium and graphite, as reflectors. Until about 1988, the reactor safety systems received power from only one source of energy. As an example, it may be cited the control desk that was powered only by the vital electrical system 220V, which, in case the electricity fails, is powered by the generator group: no-break 220V. In the years 1989 and 1990, a reform of the electrical system upgrading to increase the reactor power and, also, to meet the technical standards of the ABNT (Associacao Brasileira de Normas Tecnicas) was carried out. This work has the objective of showing the relationship between the electric power system and the IEA-R1 reactor security. Also, it demonstrates that, should some electrical power interruption occur, during the reactor operation, this occurrence would not start an accident event. (author)

  12. IPR-R1 TRIGA research reactor decommissioning plan

    International Nuclear Information System (INIS)

    Andrade Grossi, Pablo; Oliveira de Tello, Cledola Cassia; Mesquita, Amir Zacarias

    2008-01-01

    The International Atomic Energy Agency (IAEA) is concerning to establish or adopt standards of safety for the protection of health, life and property in the development and application of nuclear energy for peaceful purposes. In this way the IAEA recommends that decommissioning planning should be part of all radioactive installation licensing process. There are over 200 research reactors that have either not operated for a considerable period of time and may never return to operation or, are close to permanent shutdown. Many countries do not have a decommissioning policy, and like Brazil not all installations have their decommissioning plan as part of the licensing documentation. Brazil is signatory of Joint Convention on the safety of spent fuel management and on the safety of radioactive waste management, but until now there is no decommissioning policy, and specifically for research reactor there is no decommissioning guidelines in the standards. The Nuclear Technology Development Centre (CDTN/CNEN) has a TRIGA Mark I Research Reactor IPR-R1 in operation for 47 years with 3.6% average fuel burn-up. The original power was 100 k W and it is being licensed for 250 k W, and it needs the decommissioning plan as part of the licensing requirements. In the paper it is presented the basis of decommissioning plan, an overview and the end state / final goal of decommissioning activities for the IPR-R1, and the Brazilian ongoing activities about this subject. (author)

  13. Current activities at the FiR 1 TRIGA reactor

    International Nuclear Information System (INIS)

    Salmenhaara, Seppo

    2002-01-01

    The FiR 1 -reactor, a 250 kW Triga reactor, has been in operation since 1962. The main purpose to run the reactor is now the Boron Neutron Capture Therapy (BNCT). The epithermal neutrons needed for the irradiation of brain tumor patients are produced from the fast fission neutrons by a moderator block consisting of Al+AlF 3 (FLUENTAL), which showed to be the optimum material for this purpose. Twenty-one patients have been treated since May 1999, when the license for patient treatment was granted to the responsible BNCT treatment organization. The treatment organization has a close connection to the Helsinki University Central Hospital. The BNCT work dominates the current utilization of the reactor: three days per week for BNCT purposes and only two days per week for other purposes such as the neutron activation analysis and isotope production. In the near future the back end solutions of the spent fuel management will have a very important role in our activities. The Finnish Parliament ratified in May 2001 the Decision in Principle on the final disposal facility for spent fuel in Olkiluoto, on the western coast of Finland. There is a special condition in our operating license. We have now about two years' time to achieve a binding agreement between VTT and the Nuclear Power Plant Companies about the possibility to use the final disposal facility of the Nuclear Power Plants for our spent fuel. If this will not happen, we have to make the agreement with the USDOE with the well-known time limits. At the moment it seems to be reasonable to prepare for both spent fuel management possibilities: the domestic final disposal and the return to the USA offered by USDOE. Because the cost estimates of the both possibilities are on the same order of magnitude, the future of the reactor itself will determine, which of the spent fuel policies will be obeyed. In a couple of years' time it will be seen, if the funding of the reactor and the incomes from the BNC treatments will cover

  14. New burnup calculation of TRIGA IPR-R1 reactor

    International Nuclear Information System (INIS)

    Meireles, Sincler P. de; Campolina, Daniel de A.M.; Santos, Andre A. Campagnole dos; Menezes, Maria A.B.C.; Mesquita, Amir Z.

    2015-01-01

    The IPR-R1 TRIGA Mark I research reactor, located at the Nuclear Technology Development Center - CDTN, Belo Horizonte, Brazil, operates since 1960.The reactor is operating for more than fifty years and has a long history of operation. Determining the current composition of the fuel is very important to calculate various parameters. The reactor burnup calculation has been performed before, however, new techniques, methods, software and increase of the processing capacity of the new computers motivates new investigations to be performed. This work presents the evolution of effective multiplication constant and the results of burnup. This new model has a more detailed geometry with the introduction of the new devices, like the control rods and the samarium discs. This increase of materials in the simulation in burnup calculation was very important for results. For these series of simulations a more recently cross section library, ENDF/B-VII, was used. To perform the calculations two Monte Carlo particle transport code were used: Serpent and MCNPX. The results obtained from two codes are presented and compared with previous studies in the literature. (author)

  15. Modification of the IAN-R1 reactor

    International Nuclear Information System (INIS)

    Jaime, J.; Ahumada, S.; Spin, R.A.

    1990-01-01

    The IAN-R1 reactor is the only nuclear reactor operating in Colombia; it is installed at the Institute of Nuclear Affairs (AIN) in Bogota, which is an official body coming under the Ministry of Mining and Energy. This reactor started operation in January 1965 with a rated power of 10 kW and was modified a year later to operate at 20 kW, which has been its rated power up to the present. Given its importance for the application of nuclear technology in Columbia for various purposes, principally in the areas of neutron activation analysis, determination of uranium content in minerals using the delayed neutron counting method, production of certain radioisotopes such as 198 Au and 82 Br for engineering applications, and production of radioactive material for teaching and research purposes, research has been in progress for some years into ways of increasing its power. The study on experimental requirements and on the demand for locally produced radioisotopes came to the conclusion that its power should be increased to 1000 kW, which would allow the facility to remain on the same site. The modification includes conversion of the core to low-enriched fuel, operation up to 1 MW, modification of the shielding, renovation of instrumentation and installation of a radioisotope processing plant. When the reactor is modified we will be able to produce other radioisotopes for applications in nuclear medicine, industry and engineering; at the same time, the safety of the facility will be optimized and the experimental facilities improved

  16. Neutron radiography in the IEA-R1 reactor

    International Nuclear Information System (INIS)

    Pugliesi, R.; Moraes, A.P.V. de; Yamazaki, I.M.; Freitas Acosta, C. de.

    1988-08-01

    Neutronradiography of several materials have been obtained at the IEA-R1 Nuclear Research Reactor (IPEN-CNEN/SP), by means of two conversion techniques: a) (n, α) at the beam-hole n 0 3 where a collimated thermal neutron beam, exposure area 4 cm x 8cm and flux at the sample 10 5 n/s cm 2 is obtained. The film used was the CN-85 cellulose nitrate coated with lithium tetraborate (conversor). The time irradiation of the film was 15 minutes and in following was eteched during 30 minutes in a NaOH(10%) aqueous solution at a constant temperature of 60 0 C.; b) (n,γ) by using an experimental arrangement installed in the botton of the pool of the reactor. The flux of the collimated neutron beam is 10 5 n/s/cm 2 at the sample and the conversion is made by means of a dysprozium sheet. The film used was Kodak T-5. The irradiation and the transfering time was 2 hours and 20 hours respectively. (author) [pt

  17. Measurement of β/Λ ratio in IEA-R1 reactor using noise technique

    International Nuclear Information System (INIS)

    Moreira, J.M.L.; Kassar, E.

    1986-01-01

    The ratio β/Λ for the IEA-R1 reactor is obtained experimentally through the noise analysis technique. This technique is based on the determination of the power spectral density of the reactor neutron population, with the reactor in a subcritical state driven by a 'white' neutron source. A ratio β/Λ of 43,5 s -1 is estimated from the break frequency of the measured transfer function of the IEA-R1 reactor. (Author) [pt

  18. Modernization of control instrumentation and security of reactor IAN - R1

    International Nuclear Information System (INIS)

    Gonzalez, J. M.

    1993-01-01

    The program to modernize IAN-R1 research reactor control and safety instrumentation has been carried out considering two main aspects: updating safety philosophy requirements and acquiring the newest reactor control instrumentation controlled by computer, following the present criteria internationally recognized, for safety and reliable reactor operations and the latest developments of nuclear electronic technology. The new IAN-R1 reactor instrumentation consist of two wide range neutron monitoring channels, commanded by microprocessor a data acquisition system and reactor control, (controlled by computers). The reactor control desk is providing through two displays; all safety and control signals to the reactor operators; furthermore some signals like reactor power, safety and period signals are also showed on digital bar graphics, which are hard wired directly from the neutron monitoring channels

  19. Irradiation experience of IPEN fuel at IEA-R1 research reactor

    International Nuclear Information System (INIS)

    Perrotta, Jose A.; Neto, Adolfo; Durazzo, Michelangelo; Souza, Jose A.B. de; Frajndlich, Roberto

    1998-01-01

    IPEN/CNEN-SP produces, for its IEA-R1 Research Reactor, MTR fuel assemblies based on U 3 O 8 -Al dispersion fuel type. Since 1985 a qualification program on these fuel assemblies has been performed. Average 235 U burnup of 30% and peak burnup of 50% was already achieved by these fuel assemblies. This paper presents some results acquire, by these fuel assemblies, under irradiation at IEA-R1 Research Reactor. (author)

  20. New instrumentation for the IPR-R1 reactor of CDTN

    International Nuclear Information System (INIS)

    Carvalho, P.V.R. de.

    1992-01-01

    The Nuclear Engineering Institute reactor instrumentation area has developed systems and equipment for reactor operation and safety. In such way, the new I and C for IEN Argonauta reactor and the nuclear instrumentation for IPEN critical facility were built. This paper describes our real work, the new I and C systems for IPR-R1, a Triga type reactor, located at CDTN (Belo Horizonte - MG). (author)

  1. Modifications done in the IPR-R1 reactor and their auxiliary systems

    International Nuclear Information System (INIS)

    Maretti Junior, F.; Amorim, V.A. de; Coura, J.G.

    1986-01-01

    The improvements done in the IPR-R1 reactor for adequateness of operation conditions and increase of irradiation sample capability. The cooling systems, reactor pool, system of control rods were substituted. The optimization of transfer pneumatic system was done. (M.C.K.) [pt

  2. Calculation of radiation heat generation on a graphite reflector side of IAN-R1 Reactor

    International Nuclear Information System (INIS)

    Duque O, J.; Velez A, L.H.

    1987-01-01

    Calculation methods for radiation heat generation in nuclear reactor, based on the point kernel approach are revisited and applied to the graphite reflector of IAN-R1 reactor. A Fortran computer program was written for the determination of total heat generation in the reflector, taking 1155 point in it

  3. Measurement of thermal neutron flux spatial distribution in the IEA-R1 reactor core

    International Nuclear Information System (INIS)

    D'Utra Bitelli, U.

    1993-01-01

    This work presents the spatial thermal neutron flux in IEA-R1 reactor obtained by activation foils methods. These measurements were made in 27 fuel elements of the reactor core (165 B configuration). The results are important to compare with theoretical values, power calibration and safety analysis. (author)

  4. Thermal hydraulic analysis of the IPR-R1 TRIGA reactor

    International Nuclear Information System (INIS)

    Veloso, Marcelo Antonio; Fortini, Maria Auxiliadora

    2002-01-01

    The subchannel approach, normally employed for the analysis of power reactor cores that work under forced convection, have been used for the thermal hydraulic evaluation of a TRIGA Mark I reactor, named IPR-R1, at 250 kW power level. This was accomplished by using the PANTERA-1P subchannel code, which has been conveniently adapted to the characteristics of natural convection of TRIGA reactors. The analysis of results indicates that the steady state operation of IPR-R1 at 250 kW do not imply risks to installations, workers and public. (author)

  5. New digital control system for the operation of the Colombian research reactor IAN-R1

    International Nuclear Information System (INIS)

    Celis del A, L.; Rivero, T.; Bucio, F.; Ramirez, R.; Segovia, A.; Palacios, J.

    2015-09-01

    En 2011, Mexico won the Colombian international tender for the renewal of instrumentation and control of the IAN-R1 Reactor, to Argentina and the United States. This paper presents the design criteria and the development made for the new digital control system installed in the Colombian nuclear reactor IAN-R1, which is based on a redundant and diverse architecture, which provides increased availability, reliability and safety in the reactor operation. This control system and associated instrumentation met all national export requirements, with the safety requirements established by the IAEA as well as the requirements demanded by the Colombian Regulatory Body in nuclear matter. On August 20, 2012, the Colombian IAN-R1 reactor reached its first criticality controlled with the new system developed at Instituto Nacional de Investigaciones Nucleares (ININ). On September 14, 2012, the new control system of the Colombian IAN-R1 reactor was officially handed over to the Colombian authorities, this being the first time that Mexico exported nuclear technology through the ININ. Currently the reactor is operating successfully with the new control system, and has an operating license for 5 years. (Author)

  6. FiR 1 reactor in service for boron neutron capture therapy (BNCT) and isotope production

    International Nuclear Information System (INIS)

    Auterinen, I.; Salmenhaara, S.E.J. . Author

    2004-01-01

    The FiR 1 reactor, a 250 kW Triga reactor, has been in operation since 1962. The main purpose for the existence of the reactor is now the Boron Neutron Capture Therapy (BNCT), but FiR 1 has also an important national role in providing local enterprises and research institutions in the fields of industrial measurements, pharmaceuticals, electronics etc. with isotope production and activation analysis services. In the 1990's a BNCT treatment facility was built at the FiR 1 reactor located at Technical Research Centre of Finland. A special new neutron moderator material Fluental TM (Al+AlF3+Li) developed at VTT ensures the superior quality of the neutron beam. Also the treatment environment is of world top quality after a major renovation of the whole reactor building in 1997. Recently the lithiated polyethylene neutron shielding of the beam aperture was modified to ease the positioning of the patient close to the beam aperture. Increasing the reactor power to 500 kW would allow positioning of the patient further away from the beam aperture. Possibilities to accomplish a safety analysis for this is currently under considerations. Over thirty patients have been treated at FiR 1 since May 1999, when the license for patient treatment was granted to the responsible BNCT treatment organization, Boneca Corporation. Currently three clinical trial protocols for tumours in the brain as well as in the head and neck region are recruiting patients. (author)

  7. Thermal hydraulic analysis of the IPR-R1 TRIGA reactor; Analise termo-hidraulica do reator TRIGA IPR-R1

    Energy Technology Data Exchange (ETDEWEB)

    Veloso, Marcelo Antonio [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil); Fortini, Maria Auxiliadora [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear

    2002-07-01

    The subchannel approach, normally employed for the analysis of power reactor cores that work under forced convection, have been used for the thermal hydraulic evaluation of a TRIGA Mark I reactor, named IPR-R1, at 250 kW power level. This was accomplished by using the PANTERA-1P subchannel code, which has been conveniently adapted to the characteristics of natural convection of TRIGA reactors. The analysis of results indicates that the steady state operation of IPR-R1 at 250 kW do not imply risks to installations, workers and public. (author)

  8. Core calculations for the upgrading of the IEA-R1 research reactor

    International Nuclear Information System (INIS)

    Santos, Adimir dos; Perrotta, Jose A.; Bastos, Jose Luis F.; Yamaguchi, Mitsuo; Umbehaun, Pedro E.

    1998-01-01

    The IEA-R1 Research Reactor is a multipurpose reactor. It has been used for basic and applied research in the nuclear area, training and radioisotopes production since 1957. In 1995, the Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP) took the decision to modernize and upgrade the power from 2 to 5 MW and increase the operational cycle. This work presents the design requirements and the calculations effectuated to reach this goal. (author)

  9. Measurements and calculations of reactivity for the IEA-R1 reactor

    International Nuclear Information System (INIS)

    Ferreira, P.S.B.; Maiorino, J.R.; Yamaguchi, M.

    1988-01-01

    This work shows a measurement of reactivity parameters, such as integral and diferential control rod worth, local void coefficient, and moderator temperature coefficient for the research reactor IEA-R1. The measured values were compared with those calculated through HAMMER-CITATION codes, having shown good agreement. (author) [pt

  10. Applications of neutron activation analysis technique in the IPR-R1 research reactor

    International Nuclear Information System (INIS)

    Sabino, C.V.S.; Mansur, N.

    1986-01-01

    A review is made of the neutron activation analysis technique used in the IPR-R1 reactor of the Centro de Desenvolvimento da Tecnologia Nuclear - NUCLEBRAS. Some characteristics of the method are described, types of samples and elements analyzed are also mentioned. (Author) [pt

  11. Nuclear material control at IEA-R1 nuclear research reactor

    International Nuclear Information System (INIS)

    1988-01-01

    The control measurements system and verification of physical inventory for fuel elements used in the operation of IEA-R1 nuclear research reactor are described. The computer code used for burn-up calculation are shown. (E.G.) [pt

  12. 25th birthday of the first criticality of IPR-R1 nuclear research reactor

    International Nuclear Information System (INIS)

    Tofani, P.C.; Stasiulevicius, R.; Roedel, G.

    1988-01-01

    The historical evolution of IPR-R1 research reactor of Instituto de Pesquisas Radioativas-Nuclebras, since the data of its first criticality, is presented. The modifications and the main activities carried out, are presented. (M.C.K.) [pt

  13. IEA-R1 research reactor: operational life extension and considerations regarding future decommissioning

    International Nuclear Information System (INIS)

    Frajndlich, Roberto

    2009-01-01

    The IEA-R1 reactor is a pool type research reactor moderated and cooled by light water and uses graphite and beryllium reflectors. The reactor is located at the Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), in the city of Sao Paulo, Brazil. It is the oldest research reactor in the southern hemisphere and one of the oldest of this kind in the world. The first criticality of the reactor was obtained on September 16, 1957. Given the fact that Brazil does not have yet a definitive radioactive waste repository and a national policy establishing rules for the spent fuel storage, the institutions which operate the research reactors for more than 50 years in the country have searched internal solutions for continued operation. This paper describes the spent fuel assemblies and radioactive waste management process for the IEA-R1 reactor and the refurbishment and modernization program adopted to extend its lifetime. Some considerations about the future decommissioning of the reactor are also discussed which, in my opinion, might help the operating organization to make decisions about financial, legal and technical aspects of the decommissioning procedures in a time frame of 10-15 years(author)

  14. Experiment on continuous operation of the Brazilian IEA-R1 research reactor

    International Nuclear Information System (INIS)

    Freitas Pintaud, M. de

    1994-01-01

    In order to increase the radioisotope production in the IEA-R1 research reactor at IPEN/CNEN-SP, it has been proposed a change in its operation regime from 8 hours per day and 5 days per week to continuous 48 hours per week. The necessary reactor parameters for this new operation regime were obtained through an experiment in which the reactor was for the first time operated in the new regime. This work presents the principal results from this experiment: xenon reactivity, new shutdown margins, and reactivity loss due to fuel burnup in the new operation regime. (author)

  15. Auxiliary control system of the safety parameters for IPR-R1 reactor

    International Nuclear Information System (INIS)

    Coura, J.G.

    1986-01-01

    This paper deals with the description for the control of three cooling water parameters (conductivity, temperature and the maximum and minimum water levels) as well as the percent power fraction of the nuclear research reactor IPR-R1. In order to keep the reactor in good operation conditions, one permanent and accurate control of the cooling water is needed. The double monitoring of a fourth parameter, part of the original design, the percent power fraction, is obtained through the control of the uncompensated ion chamber current and aims to avoid the operation of the reactor without running the cooling system. (Author) [pt

  16. Calculation of the main neutron parameters of the IEA-R1 research reactor

    International Nuclear Information System (INIS)

    Ojima, Mario Katsuhiko

    1977-01-01

    The main neutron parameters of the research reactor IEA-R1 were calculated using computer programs to generate cross sections and criticality calculations. A calculation procedure based on the programs available in the Processing Center Data of IEA was established and centered in the HAMMER and CITATION system. A study was done in order to verify the validity and accuracy of the calculation method comparing the results with experimental data. Some operating parameters of the reactor, namely the distribution of neutron flux, the critical mass, the variation of the reactivity with the burning of fuel, and the dead time of the reactor were determined

  17. Measurement of the thermal flux distribution in the IEA-R1 reactor

    International Nuclear Information System (INIS)

    Tangari, C.M.; Moreira, J.M.L.; Jerez, R.

    1986-01-01

    The knowledge of the neutron flux distribution in research reactors is important because it gives the power distribution over the core, and it provides better conditions to perform experiments and sample irradiations. The measured neutron flux distribution can also be of interest as a means of comparison for the calculational methods of reactor analysis currently in use at this institute. The thermal neutron flux distribution of the IEA-R1 reactor has been measured with the miniature chamber WL-23292. For carrying out the measurements, it was buit a guide system that permit the insertion of the mini-chamber i between the fuel of the fuel elements. It can be introduced in two diferent positions a fuel element and in each it spans 26 axial positions. With this guide system the thermal neutron flux distribution of the IEA-R1 nuclear reactor can be obtained in a fast and efficient manner. The element measured flux distribution shows clearly the effects of control rods and reflectors in the IEA-R1 reactor. The difficulties encountered during the measurements are mentioned with detail as well as the procedures adopteed to overcome them. (Author) [pt

  18. Spent fuel management - two alternatives at the FiR 1 reactor

    International Nuclear Information System (INIS)

    Salmenhaara, S.E.J.

    2001-01-01

    The FiR 1 -reactor, a 250 kW Triga reactor, has been in operation since 1962. The reactor with its subsystems has experienced a large renovation work in 1996-97. The main purpose of the upgrading was to install the new Boron Neutron Capture Therapy (BNCT) irradiation facility. The BNCT work dominates the current utilization of the reactor: four days per week for BNCT purposes and only one day per week for neutron activation analysis and isotope production. The Council of State (government) granted for the reactor a new operating license for twelve years starting from the beginning of the year 2000. There is however a special condition in the new license. We have to achieve a binding agreement between our Research Centre and the domestic Nuclear Power Plant Companies about the possibility to use the final disposal facility of the Nuclear Power Plants for our spent fuel, if we want to continue the reactor operation beyond the year 2006. In addition to the choosing of one of the spent fuel management alternatives the future of the reactor will also depend strongly on the development of the BNCT irradiations. If the number of patients per year increases fast enough and the irradiations of the patients will be economically justified, the operation of the reactor will continue independently of the closing of the USDOE alternative in 2006. Otherwise, if the number of patients will be low, the funding of the reactor will be probably stopped and the reactor will be shut down. (author)

  19. Use of self powered neutron detectors in the IEA-R1 reactor

    International Nuclear Information System (INIS)

    Galo Rocha, F. del.

    1989-01-01

    A survey of self-powered neutron detectors, SPND, which are used as part of the in-core instrumentation of nuclear reactors is presented. Measurements with Co and Er SPND's were made in the IEA-R1 reactor for determining the neutron flux distribution and the integral reactor power. Due to the size of the available detectors, the neutron flux distribution could not be obtained with accuracy. The results obtained in the reactor power measurements demonstrate that the SPND have the linearity and the quick response necessary for a reactor power channel. This work also presents a proposed design of a SPND using Pt as wire emissor. This proposed design is based in the experience gained in building two prototypes. The greatest difficulties encountered include materials and technology to perform the delicate weldings. (author)

  20. Borated stainless steel storage project to the spent fuel of the IEA-R1 reactor

    International Nuclear Information System (INIS)

    Rodrigues, Antonio Carlos Iglesias; Madi Filho, Tufic; Ricci Filho, Walter

    2013-01-01

    The IEA-R1 research reactor operates in a regimen of 64h weekly, at the power of 4.5 MW. In these conditions, the racks to the spent fuel elements have less than half of its initial capacity. Thus, maintaining these operating circumstances, the storage will have capacity for approximately six years. Whereas the estimated useful life of the IEA-R1 is around twenty years, it will be necessary to increase the storage capacity for the spent fuel. Dr. Henrik Grahn, expert of the International Atomic Energy Agency on wet storage, visiting the IEA-R1 Reactor (September/2012) made some recommendations: among them, the design and installation of racks made with borated stainless steel and internally coated with an aluminum film, so that corrosion of the fuel elements would not occur. This work objective is the project of high capacity storage for spent fuel elements, using borated stainless steel, to answer the Reactor IEA-R1 demand and the security requirements of the International Atomic Energy Agency. (author)

  1. Design of a new wet storage rack for spent fuels from IEA-R1 reactor

    International Nuclear Information System (INIS)

    Rodrigues, Antonio C.I.; Madi Filho, Tufic; Siqueira, Paulo T.D.; Ricci Filho, Walter

    2015-01-01

    The IEA-R1 research reactor operates in a regimen of 64h weekly, at the power of 4.5 MW. In these conditions, the racks of the spent fuel elements have less than half of its initial capacity. Thus, maintaining these operating conditions, the storage will have capacity for about six years. Since the estimated useful life of the IEA-R1 is about another 20 years, it will be necessary to increase the storage capacity of spent fuel. Dr. Henrik Grahn, expert of the International Atomic Energy Agency on wet storage, visiting the IEA-R1 Reactor (September/2012) made some recommendations: among them, the design and installation of racks made with borated stainless steel and internally coated with an aluminum film, so that corrosion of the fuel elements would not occur. After an extensive literature review of material options given for this type of application we got to Boral® manufactured by 3M due to numerous advantages. This paper presents studies on the analysis of criticality using the computer code MCNP 5, demonstrating the possibility of doubling the storage capacity of current racks to attend the demand of the IEA-R1 reactor while attending the safety requirements the International Atomic Energy Agency. (author)

  2. Design of a new wet storage rack for spent fuels from IEA-R1 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Antonio C.I.; Madi Filho, Tufic; Siqueira, Paulo T.D.; Ricci Filho, Walter, E-mail: acirodri@ipen.br, E-mail: tmfilho@ipen.br, E-mail: ptsiquei@ipen.br, E-mail: wricci@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    The IEA-R1 research reactor operates in a regimen of 64h weekly, at the power of 4.5 MW. In these conditions, the racks of the spent fuel elements have less than half of its initial capacity. Thus, maintaining these operating conditions, the storage will have capacity for about six years. Since the estimated useful life of the IEA-R1 is about another 20 years, it will be necessary to increase the storage capacity of spent fuel. Dr. Henrik Grahn, expert of the International Atomic Energy Agency on wet storage, visiting the IEA-R1 Reactor (September/2012) made some recommendations: among them, the design and installation of racks made with borated stainless steel and internally coated with an aluminum film, so that corrosion of the fuel elements would not occur. After an extensive literature review of material options given for this type of application we got to Boral® manufactured by 3M due to numerous advantages. This paper presents studies on the analysis of criticality using the computer code MCNP 5, demonstrating the possibility of doubling the storage capacity of current racks to attend the demand of the IEA-R1 reactor while attending the safety requirements the International Atomic Energy Agency. (author)

  3. Borated stainless steel storage project to the spent fuel of the IEA-R1 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Antonio Carlos Iglesias; Madi Filho, Tufic; Ricci Filho, Walter, E-mail: acirodri@ipen.br, E-mail: tmfilho@ipen.br, E-mail: wricci@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The IEA-R1 research reactor operates in a regimen of 64h weekly, at the power of 4.5 MW. In these conditions, the racks to the spent fuel elements have less than half of its initial capacity. Thus, maintaining these operating circumstances, the storage will have capacity for approximately six years. Whereas the estimated useful life of the IEA-R1 is around twenty years, it will be necessary to increase the storage capacity for the spent fuel. Dr. Henrik Grahn, expert of the International Atomic Energy Agency on wet storage, visiting the IEA-R1 Reactor (September/2012) made some recommendations: among them, the design and installation of racks made with borated stainless steel and internally coated with an aluminum film, so that corrosion of the fuel elements would not occur. This work objective is the project of high capacity storage for spent fuel elements, using borated stainless steel, to answer the Reactor IEA-R1 demand and the security requirements of the International Atomic Energy Agency. (author)

  4. Commissioning of the new heat exchanger for the research nuclear reactor IEA-R1

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Alfredo Jose Alvim de; Cassiano, Douglas Alves; Umbehaun, Pedro Ernesto; Carvalho, Marcos Rodrigues de; Frajndlich, Roberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mails: ajcastro@ipen.br; docass@gmail.com.br; umbehaun@ipen.br; carvalho@ipen.br; frajndli@ipen.br

    2008-07-01

    The Research Reactor IEA-R1 placed at IPEN/CNEN-SP is of the swimming pool type, light water moderated and with graphite reflectors, and was build and designed by Babcock and Wilcox Co. Start up operation was in September the 16{sup th}, 1957, being the first criticality for South Hemisphere. Although designed to operate at 5 MW, the IEA-R1 was operated until 2001 with 2 MW and was suitable for use in basic and applied research as well as the production of medical radioisotopes, industry and natural sciences applications. Due to a recent demand increase on radioisotopes in Brazil for medical diagnoses and therapies applications, IPEN /CNEN updated the IEA-R1 power to 5 MW and to work at continuous operation regime. Studies on the Ageing Management for the Research Reactor IEA-R1 were conducted according to IAEA procedures. As result of these studies critical components within the Ageing Management Program were identified. Also were made recommendations on the implementation of test scheduling and standardization procedures to organize data and documents. One of the main results was the need of monitoring the two heat exchangers, the two primary circuit pumps and the data acquisition system. During monitoring procedures, issues were observed on the IEA-R1 operation at 5 MW mainly due to the ageing of the Babcox and Wilcox TCA heat exchanger, and excessive vibrations at high flow rates on CBC's TCB heat exchanger. So, from 2005 on, it was decided to work with 3,5 MW and provide a new IESA heat exchanger with 5 MW capacity, to substitute the TCA heat exchanger. This work presents results on the commissioning of the new heat exchanger and compares against the values calculated in the IESA project. The results show that the IEA-R1 Reactor can be operated more safety and continuously at 5 MW with the new IESA heat exchanger. (author)

  5. Experimental study of the temperature distribution in the TRIGA IPR-R1 Brazilian research reactor

    International Nuclear Information System (INIS)

    Mesquita, Amir Zacarias

    2005-01-01

    The TRIGA-IPR-R1 Research Nuclear Reactor has completed 44 years in operation in November 2004. Its initial nominal thermal power was 30 kW. In 1979 its power was increased to 100 kW by adding new fuel elements to the reactor. Recently some more fuel elements were added to the core increasing the power to 250 kW. The TRIGA-IPR-R1 is a pool type reactor with a natural circulation core cooling system. Although the large number of experiments had been carried out with this reactor, mainly on neutron activation analysis, there is not many data on its thermal-hydraulics processes, whether experimental or theoretical. So a number of experiments were carried out with the measurement of the temperature inside the fuel element, in the reactor core and along the reactor pool. During these experiments the reactor was set in many different power levels. These experiments are part of the CDTN/CNEN research program, and have the main objective of commissioning the TRIGA-IPR-R1 reactor for routine operation at 250 kW. This work presents the experimental and theoretical analyses to determine the temperature distribution in the reactor. A methodology for the calibration and monitoring the reactor thermal power was also developed. This methodology allowed adding others power measuring channels to the reactor by using thermal processes. The fuel thermal conductivity and the heat transfer coefficient from the cladding to the coolant were also experimentally valued. lt was also presented a correlation for the gap conductance between the fuel and the cladding. The experimental results were compared with theoretical calculations and with data obtained from technical literature. A data acquisition and processing system and a software were developed to help the investigation. This system allows on line monitoring and registration of the main reactor operational parameters. The experiments have given better comprehension of the reactor thermal-fluid dynamics and helped to develop numerical

  6. Calculation of neutronic parameters of IEA-R1 reactor and purpose of a new configuration

    International Nuclear Information System (INIS)

    Kosaka, N.; Fanaro, L.C.C.B.; Yamaguchi, M.

    1989-01-01

    The program for reducing the fuel enrichment of the IEA-R1 reactor considers fuel plates containing U308-AL with 19,9% of U-235. The geometry of the new 18 fuel plate fuel elements has been kept the same. This work describes the calculation methods utilized at IPEN-CNEN/SP and some neutronic parameters of the present configuration of IEA-R1 as well as for a new configuration porposed with a new LEU fuel element are shown. (author) [pt

  7. Experimental study of the IPR-R1 TRIGA reactor power channels responses

    International Nuclear Information System (INIS)

    Mesquita, Henrique F.A.; Ferreira, Andrea V.

    2015-01-01

    The IPR-R1 nuclear reactor installed at Centro de Desenvolvimento da Tecnologia Nuclear CDTN/CNEN, Belo Horizonte, Brazil, is a Mark I TRIGA reactor (Training, Research, Isotopes, General Atomics) and became operational on November of 1960. The reactor has four irradiation devices: a rotary specimen rack with 40 irradiation channels, the central tube, and two pneumatic transfer tubes. The nuclear reactor is operated in a power range between zero and 100 kW. The instrumentation for IPR-R1 operation is mainly composed of four neutronic channels for power measurements. The aim of this work is to investigate the responses of neutronic channels of IPR-R1, Linear, Log N and Percent Power channels, and to check their linearity. Gold foils were activated at low powers (0.125-1.000 kW), and cobalt foils were activated at high powers (10-100kW). For each sample irradiated at rotary specimen rack, another one was irradiated at the same time at the pneumatic transfer tube-2. The obtained results allowed evaluating the linearity of the neutronic channels responses. (author)

  8. NBR ISO 9001 Certification for activities carried out in IEA-R1 reactor

    International Nuclear Information System (INIS)

    Paiva, Rosemeire P.; Salvetti, Tereza C.

    2005-01-01

    Since its inauguration in 1957, the IEA-R1 research reactor has been used mainly for research, development and teaching by scientific community. In the last years, with the increase of the commercial radiopharmaceutical production by Radiopharmacy Center of IPEN, the IEA-R1 reactor was recognized as a service supplier for that center and has received a treatment more commercial from IPEN Management. In 1999 the radiopharmaceutical production obtained the NBR ISO 9002 Certification, since that the IPEN Management considered convenient to invest in the certification of its internal suppliers. In this context, in 2001 the Research Reactor Center (CRPq) began the implantation of a Quality Management System (QMS) based on NBR 9001: 2000 standard, for activities related to the operation and maintenance of the IEA-R1 research reactor and irradiation services. This QMS was structured to incorporate tools already implemented in order to complain the requirements related to nuclear and radiological safe for a nuclear installation established by the regulatory organism. The QMS is supported by a documentation system composed of approximately 150 documents including quality manual, business and action plans, operational procedures and work instruction. Carlos Alberto Vanzolini Foundation (FCAV), an INMETRO certified organism, certified the 'Operation and Maintenance of the IEA-R1 Research Reactor and Irradiation Services' in December 2002. In 2003 and 2004, the QMS was audited by FCAV that determined the maintenance of the certification. This work presents the main steps of the QMS implementation, including the difficulties found and results obtained in the process. (author)

  9. Neutrons characterization of the nuclear reactor Ian-R1 of Colombia; Caracterizacion de los neutrones del reactor nuclear IAN-R1 de Colombia

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez P, L. X.; Martinez O, S. A. [Universidad Pedagogica y Tecnologica de Colombia, Grupo de Fisica Nuclear Aplicada y Simulacion, Carretera Central del Norte Km. 1, Via Paipa, 150003 Tunja, Boyaca (Colombia); Vega C, H. R., E-mail: s.agustin.martinez@uptc.edu.co [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2014-08-15

    By means of Monte Carlo methods, with the code MCNPX, the neutron characteristics of the research nuclear reactor Ian-R1 of Colombia, in power off but with the neutrons source in their start position, have been valued. The neutrons spectra, the total flow and their average power were calculated in the irradiation spaces inside the graphite reflector, as well as in the cells with air. Also the spectra, the total flow and the absorbed dose were calculated in several places distributed along the radial shaft inside the water moderator. The neutrons total flow was also considered to the long of the axial shaft. The characteristics of the neutrons spectra vary depending on their position regarding the source and the material that surrounds to the cell where the calculation was made. (Author)

  10. IEA-R1 reactor core simulation with RELAP5 code

    International Nuclear Information System (INIS)

    Rocha, Ricardo Takeshi Vieira da; Belchior Junior, Antonio; Andrade, Delvonei Alves de; Sabundjian, Gaiane; Umbehaum, Pedro Ernesto; Torres, Walmir Maximo

    2005-01-01

    This paper presents a preliminary RELAP5 model for the IEA-R1 core. The power distribution is supplied by the neutronic code, CITATION. The main objective is to model the IEA-R1 core and validate the model through the comparison of the results to the ones from COBRA and PARET, which were used in the Final Safety Analysis Report (FSAR) for this plant. Preliminary calculations regarding some simulations are presented. Boundary conditions are simulated through time dependent components. Results obtained are compared to those available for the IEA-R1. This study will be continued considering a model for the whole plant. Important transient and accidents will be analysed in order to verify the Emergency Core Cooling System - ECCS efficiency to hold its function as projected to preserve the integrity of the reactor core and guarantee its cooling. (author)

  11. Calculations and selection of a TRIGA core for the Nuclear Reactor IAN-R1

    International Nuclear Information System (INIS)

    Castiblanco, L.A.; Sarta, J.A.

    1997-01-01

    The Reactor Group used the code WIMS reduced to five groups of energy, together with the code CITATION, and evaluated four configurations for a core, according to the grid actually installed. The four configurations were taken from the two proposals presented to the Instituto de Ciencias Nucleares y Energias Alternativas by General Atomics Company. In this paper, the Authors selected the best configuration according to the performance of flux distribution and excess reactivity, for a TRIGA core to be installed in the Nuclear Reactor IAN-R1

  12. Development of a training simulator to operators of the IEA-R1 research reactor

    International Nuclear Information System (INIS)

    Carvalho, Ricardo Pinto de

    2006-01-01

    This work reports the development of a Simulator for the IEA-R1 Research Reactor. The Simulator was developed with Visual C++ in two stages: construction of the mathematics models and development and configuration of graphics interfaces in a Windows XP executable. A simplified modeling was used for main physics phenomena, using a point kinetics model for the nuclear process and the energy and mass conservation laws in the average channel of the reactor for the thermal hydraulic process. The dynamics differential equations were solved by using finite differences through the 4th order Runge- Kutta method. The reactivity control, reactor cooling, and reactor protection systems were also modeled. The process variables are stored in ASCII files. The Simulator allows navigating by screens of the systems and monitoring tendencies of the operational transients, being an interactive tool for teaching and training of IEA-R1 operators. It also can be used by students, professors, and researchers in teaching activities in reactor and thermal hydraulics theory. The Simulator allows simulations of operations of start up, power maneuver, and shut down. (author)

  13. Verification of the linearity of the IPR-R1 TRIGA reactor power channels

    International Nuclear Information System (INIS)

    Souza, Rose Mary Gomes do Prado; Campolina, Daniel de Almeida Magalhaes

    2013-01-01

    The aim of this paper is to verify the linearity of the three power channels of the IPR-R1 TRIGA reactor. Located at Nuclear Technology Development Center-CDTN in Belo Horizonte, the IPR-R1 reactor is a typical 100 kW Mark I light-water reactor cooled by natural convection. When the experiments were performed, the reactor core had 59 fuel elements, containing 8% by weight of uranium enriched to 20% in 235 U. The core has cylindrical configuration with an annular graphite reflector. The responses of the detectors of the Linear, Log N and Percent Power channels were compared with the responses of detectors which only depend on the overall neutron flux within the reactor. Gold and cobalt foils were activated at low and high powers, respectively, and the specific count results were compared with measurements performed, simultaneously, with a fission chamber, and with the power registered by the three channels. The results show that the Linear channel responds linearly up to 100 kW, and the Log N channel responses are linear at low powers. In the range of high power, the Log N and the Percent Power channels exhibit linearity only from 10 kW to 50 kW. (author)

  14. Neutron flux measurement and thermal power calibration of the IAN-R1 TRIGA reactor

    Energy Technology Data Exchange (ETDEWEB)

    Sarta Fuentes, Jose A.; Castiblanco Bohorquez, Luis A

    2008-10-29

    The IAN-R1 TRIGA reactor in Colombia was initially fueled with MTR-HEU enriched to 93% U-235, operated since 1965 at 10 kW, and was upgraded to 30 kW in 1980. General Atomics achieved in 1997 the conversion of HEU fuel to LEU fuel TRIGA type, and upgraded the reactor power to 100 kW. Since the IAN-R1 TRIGA reactor was in an extended shutdown during seven years, it was necessary to repeat some results of the commissioning test conducted in 1997. The thermal power calibration was carried out using the calorimetric method. The reactor was operated approximately at 20 kW during 3.5 hours, with manual power corrections since the automatic control system failed and with the forced refrigeration off. During the calorimetric experiment, the pool temperature was measured with a RTD which is installed near to the core. The dates were collected in intervals of 30 minutes. For establishing thermal power reactor, the water temperature versus the running were registered. For a calculated tank volume of 16 m{sup 3}, the tank constant calculated for the IAN-R1 TRIGA reactor is 0.0539 C/kW-hr. The reactor power determined was 19 kW. The core configuration is a rectangular grid plate that holds a combination of 4-rod and 3-rod clusters. The core contains 50 fuel rods with LEU fuel TRIGA (UZr H1.6) type enriched to 19.7%. The radial reflector consists of twenty graphite elements six of which are used for isotope production. The top an bottom reflectors are the cylindrical graphite end reflectors which are installed above and below of the active fuel section in each fuel rod. The spatial dependence of thermal neutron flux was measured axially in the 3-rod clusters 4C, 3D, 5E and in the 4F graphite element. The spatial distribution of the thermal neutron was determined using a self-powered detector and the absolute value of thermal neutron flux was determined by a gold activation detector. The (n, b- ) reaction is applied to determine the relative spatial distribution of thermal

  15. Aspects of the Iea-R1 research reactor seismic evaluation

    International Nuclear Information System (INIS)

    Mattar Neto, Miguel

    1996-01-01

    Codes and standards for the seismic evaluation of the research reactor IEA-R1 are presented. An approach to define the design basis earthquake based on the local seismic map and on simplified analysis methods is proposed. The site seismic evaluation indicates that the design earthquake intensity is IV MM. Therefore, according to the used codes and standards, no buildings, systems, and components seismic analysis are required. (author)

  16. Feasibility studies of producing 99 Mo by capture in the IEA-R1 research reactor

    International Nuclear Information System (INIS)

    Concilio, Roberta; Mendonca, Arlindo Gilson; Maiorino, Jose Rubens

    1998-01-01

    Everyday the production of 99 Mo for 99m Tc generators, becomes more necessary, whose properties are ideal for medical diagnosis. This works presents a description and an analysis of the production of 99 Mo by radioactive capture at 98 Mo using the research reactor IEA-R1 in 5 MW and operating 5 days a week, referring to the use of targets, separation methods, total and specific activity attained and its limitations. (author)

  17. Ageing Management Programme for the IEA-R1 Reactor in São Paulo, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Ramanathan, L. V. [Institute of Energy and Nuclear Research (IPEN), National Nuclear Energy Commission (CNEN), São Paulo (Brazil)

    2014-08-15

    IEA-R1 is a swimming pool type reactor. It is moderated and cooled by light water and uses graphite and beryllium as reflector elements. First criticality was achieved on 16 September 1957, and the reactor is currently operating at 4.0 MW on a 64 h per week cycle. In 1996, a reactor ageing study was established to determine general deterioration of systems and components such as cooling towers, secondary cooling system, piping, pumps, specimen irradiation devices, radiation monitoring system, fuel elements, rod drive mechanisms, nuclear and process instrumentation, and safety system. The basic structure of the reactor from the original design has been maintained, but several improvements and modifications have been made over the years to various components, systems and structures. During the period 1996–2005 the reactor power was increased from 2 MW to 5 MW and the operational cycle from 8 h per day for 5 days a week to 120 h continuous per week, mainly to increase production of {sup 99}Mo. Prior to increasing reactor power, several modifications were made to the reactor system and its components. Simultaneously, a vigorous ageing management, inspection and modernization programme was put in place.

  18. Spent fuel management plans for the FiR 1 Reactor

    International Nuclear Information System (INIS)

    Salmenhaara, S. E. J.

    2002-01-01

    The FiR 1-reactor, a 250 kW TRIGA reactor, has been in operation since 1962. The main purpose to run the reactor is now the Boron Neutron Capture Therapy (BNCT). The BNCT work dominates the current utilization of the reactor: three days per week for BNCT purposes and only two days per week for other purposes such as the neutron activation analysis and isotope production. The final disposal site is situated in Olkiluoto, on the western coast of Finland. Olkiluoto is also one of the two nuclear power plant sites in Finland. In the new operating license of our reactor there is a special condition. We have to achieve a binding agreement between our Research Centre and either the domestic Nuclear Power Companies about the possibility to use the Olkiluoto final disposal facility for our spent fuel or US DOE about the return of our spent fuel back to USA. If we want to continue the reactor operation beyond the year 2006. the domestic final disposal is the only possibility. At the moment it seems to be reasonable to prepare to both possibilities: the domestic final disposal and the return to the USA offered by US DOE. Because the cost estimates of the both possibilities are on the same order of magnitude, the future of the reactor itself will decide, which of the spent fuel policies will be obeyed. In a couple of years' time it will be seen, if the funding of the reactor and the incomes from the BNCT treatments will cover the costs. If the BNCT and other irradiations develop satisfactorily, the reactor can be kept in operation beyond the year 2006 and the domestic final disposal will be implemented. If, however, there is still lack of money, there is no reason to continue the operation of the reactor and the choice of US DOE alternative is natural. (author)

  19. Measurements and calculation of reactivity in the IEA-R1 nuclear reactor

    International Nuclear Information System (INIS)

    Ferreira, P.S.B.

    1988-01-01

    Techniques and experimentals procedures utilized in the measurement of some nuclear parameters related to reactivity are presented. Measurements of reactivity coefficients, such as void, temperature and power, and control rod worth were made in the IEA-R1 Research Reactor. The techniques used to perform the measurements were: i) stable period (control rod calibration), ii) inverse kinetics (digital reactivity meter), iii) aluminium slab insertion in the fuel element coolant channels (void reactivity), iv) nuclear reactor core temperature changes by means of the changes in the coolant systems of reactor core (isothermal reactivity coefficient) and v) by making perturbation in the core through the control rod motions (power reactivity coefficient and control rod calibration). By using the computer codes HAMMER, HAMMER-TECHNION and CITATION, the experiments realized in the IEA-R1 reactor were simulated. From this simulation, the theoretical reactivity parameters were estimated and compared with the respective experimental results. Furthermore, in the second fuel load of Angra-1 Nuclear Power Station, the IPEN-CNEN/SP digital reactivity - meter were used in the lower power test with the aim to assess the equipment performance. Among several tests, the reacticity-meter were used in parallel with a Westinghouse analogic reativimeter-meter) to measure the heat additiona point, critical boron concentration, control rod calibration, isothermal and moderator reactivity coefficient. These tests, and the results obtained by the digital reactivity-meter are described. The results were compared with those obtained by Westinghouse analogic reactivity meter, showing excellent agreement. (author) [pt

  20. Assessment of a RELAP5 model for the IPR-R1 TRIGA research reactor

    International Nuclear Information System (INIS)

    Reis, Patricia A.L.; Costa, Antonella L.; Pereira, Claubia; Veloso, Maria A.F.; Mesquita, Amir Z.; Soares, Humberto V.

    2010-01-01

    RELAP5 code was developed at the Idaho National Environmental and Engineering Laboratory and it is widely used for thermal hydraulic studies of commercial nuclear power plants and, currently, it has been also applied for thermal hydraulic analysis of nuclear research systems with good predictions. This work is a contribution to the assessment of RELAP5/3.3 code for research reactors analysis. It presents steady-state and transient calculation results performed using a RELAP5 model to simulate the IPR-R1 TRIGA research reactor conditions operating at 50 and 100 kW. The reactor is located at the Nuclear Technology Development Centre (CDTN), Brazil. The development and the assessment of a RELAP5 model for the IPR-R1 TRIGA are presented. Experimental data were considered in the process of code-to-data validation. The RELAP5 results were also compared with calculation performed using the STHIRP-1 (Research Reactors Thermal Hydraulic Simulation) code. The use of a cross flow model has been essential to improve results in the transient condition respect to preceding investigations.

  1. Experience and research with the IEA-R1 Brazilian reactor

    International Nuclear Information System (INIS)

    Fulfaro, R.; Sousa, J.A. de; Nastasi, M.J.C.; Vinhas, L.A.; Lima, F.W.

    1982-06-01

    The IEA-R1 reactor of the Instituto de Pesquisas Energeticas e Nucleares, IPEN, of Sao Paulo, Brazil, a lightwater moderated swimming-pool research reactor of MTR type, went critical for the first time on September 16, 1957. In a general way, in these twenty four years the reactor was utilized without interruption by users of IPEN and other institutions, for the accomplishment of work in the field of applied and basic research, for master and doctoral thesis and for technical development. Some works performed and the renewal programme established for the IEA-R1 research reactor in which several improvements and changes were made. Recent activities in terms of production of radioisotopes and some current research programm in the field of Radiochemistry are described, mainly studies and research on chemical reactions and processes using radioactive tracers and development of radioanalytical methods, such as neutron activation and isotopic dilution. The research programmes of the Nuclear Physics Division of IPEN, which includes: nuclear spectroscopy studies and electromagnetic hyperfine interactions; neutron diffraction; neutron inelastic scattering studies in condensed matter; development and application of the technique of fission track register in solid state detectors; neutron radioactive capture with prompt gamma detection and, finally, research in the field of nuclear metrology, are presented. (Author) [pt

  2. Experience and research with the IEA-R1 Brazilian reactor

    International Nuclear Information System (INIS)

    Fulfaro, R.; Sousa, J.A. de; Nastasi, M.J.C.; Vinhas, L.A.; Lima, F.W. de.

    1982-06-01

    The IEA-R1 reactor of the Instituto de Pesquisas Energeticas e Nucleares, IPEN, of Sao Paulo, Brazil, a lighwater moderated swimming-pool research reactor of MTR type, went critical for the first time on September 16, 1957. In a general way, in these twenty four years the reactor was utilized without interruption by users of IPEN and other institutions, for the accomplishment of work in the field of applied and basic research, for master and doctoral thesis and for technical development. Some works performed and the renewal programme established for the IEA-R1 research reactor in which several improvements and changes were made. Recent activities in terms of production of radioisotopes and some current research programm in the field of Radiochemistry are described, mainly studies and research on chemical reactions and processes using radioactive tracers and development of radioanalytical methods, such as neutron activation and isotopic dilution. It is also presented the research programmes of the Nuclear Physics Division of IPEN, which includes: nuclear spectroscopy studies and electromagnetic hyperfine interactions; neutron diffraction; neutron inelastic scattering studies in condensed matter; development and application of the technique of fission track register in solid state detectors; neutron radioactive capture with prompt gamma detection and, finally, research in the field of nuclear metrology. (Author) [pt

  3. Modernization of Safety and Control Instrumentation of the IEA-R1 Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    De Carvalho, P.V., E-mail: paulov@ien.gov.br [Institute of Nuclear Engineering (IEN), National Nuclear Energy Commission (CNEN), Rio de Janeiro (Brazil)

    2014-08-15

    The research reactor IEA-R1 located in the Institute of Energy and Nuclear Research (IPEN), São Paulo, Brazil, obtained its first criticality on 16 September 1957 and since then has served the scientific and medical community in the performance of experiments in applied nuclear physics, as well as the provision of radioisotopes for production of radiopharmaceuticals. The reactor produces radioisotopes {sup 82}Br and {sup 41}Ar for special processes in industrial inspection and {sup 192}Ir and {sup 198}Au as sources of radiation used in brachytherapy, {sup 153}Sm for pain relief in patients with bone metastasis, and calibrated sources of {sup 133}Ba, {sup 137}Cs, {sup 57}Co, {sup 60}Co, {sup 241}Am and {sup 152}Eu used in medical clinics and hospitals practicing nuclear medicine and research laboratories. Services are offered in regular non-destructive testing by neutron radiography, neutron irradiation of silicon for phosphorous doping and other various irradiations with neutrons. The reactor is responsible for producing approximately 70% of radiopharmaceutical {sup 131}I used in Brazil, which saves about US$ 800 000 annually for the country. After more than 50 years of use, most of its equipment and systems have been modernized, and recently the reactor power was increased to 5 MW in order to enhance radioisotope production capability. However, the control room and nuclear instrumentation system used for reactor safety have operated more than 30 years and require constant maintenance. Many equipment and electronic components are obsolete, and replacements are not available in the market. The modernization of the nuclear safety and control instrumentation systems of IEA-R1 is being carried out with consideration for the internationally recognized criteria for safety and reliable reactor operations and the latest developments in nuclear electronic technology. The project for the new reactor instrumentation system specifies three wide range neutron monitoring

  4. Digital Systems Implemented at the IPEN Nuclear Research Reactor (IEA-R1): Results and Necessities

    International Nuclear Information System (INIS)

    Nahuel-Cardenas, Jose-Patricio; Madi-Filho, Tufic; Ricci-Filho, Walter; Rodrigues-de-Carvalho, Marcos; Lima-Benevenuti, Erion-de; Gomes-Neto, Jose

    2013-06-01

    (Nuclear and Energy Research Institute) was founded in 1956 with the main purpose of doing research and development in the field of nuclear energy and its applications. It is located at the campus of University of Sao Paulo (USP), in the city of Sao Paulo, in an area of nearly 500, 000 m2. It has over 1.000 employees and 40% of them have qualification at master or doctor level The institute is recognized as a national leader institution in research and development (R and D) in the areas of radiopharmaceuticals, industrial applications of radiation, basic nuclear research, nuclear reactor operation and nuclear applications, materials science and technology, laser technology and applications. Along with the R and D, it has a strong educational activity, having a graduate program in Nuclear Technology, in association with the University of Sao Paulo, ranked as the best university in the country. The Federal Government Evaluation institution CAPES, granted to this course grade 6, considering it a program of Excellence. This program started at 1976 and has awarded 458 Ph.D. degrees and 937 master degrees since them. The actual graduate enrollment is around 400 students. One of major nuclear installation at IPEN is the IEA-R1 research reactor; it is the only Brazilian research reactor with substantial power level suitable for its utilization in researches concerning physics, chemistry, biology and engineering as well as for producing some useful radioisotopes for medical and other applications. IEA-R1 reactor is a swimming pool type reactor moderated and cooled by light water and uses graphite and beryllium as reflectors. The first criticality was achieved on September 16, 1957. The reactor is currently operating at 4.5 MW power level with an operational schedule of continuous 64 hours a week. In 1996 a Modernization Program was started to establish recommendations in order to mitigate equipment and structures ageing effects in the reactor components, detect and evaluate

  5. Measured and calculated effective delayed neutron fraction of the IPR-R1 Triga reactor

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Rose Mary G.P.; Dalle, Hugo M.; Campolina, Daniel A.M., E-mail: souzarm@cdtn.b, E-mail: dallehm@cdtn.b, E-mail: campolina@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    The effective delayed neutron fraction, {beta}{sub eff}, one of the most important parameter in reactor kinetics, was measured for the 100 kW IPR-R1 TRIGA Mark I research reactor, located at the Nuclear Technology Development Center - CDTN, Belo Horizonte, Brazil. The current reactor core has 63 fuel elements, containing about 8.5% and 8% by weight of uranium enriched to 20% in U{sup 235}. The core has cylindrical configuration with an annular graphite reflector. Since the first criticality of the reactor in November 1960, the core configuration and the number of fuel elements have been changed several times. At that time, the reactor power was 30 kW, there were 56 fuel elements in the core, and the {beta}{sub eff} value for the reactor recommended by General Atomic (manufacturer of TRIGA) was 790 pcm. The current {beta}{sub eff} parameter was determined from experimental methods based on inhour equation and on the control rod drops. The estimated values obtained were (774 {+-} 38) pcm and (744 {+-} 20) pcm, respectively. The {beta}{sub eff} was calculated by Monte Carlo transport code MCNP5 and it was obtained 747 pcm. The calculated and measured values are in good agreement, and the relative percentage error is -3.6% for the first case, and 0.4% for the second one. (author)

  6. The IPR-R1 TRIGA Mark I Reactor in 39 years: Operations and general improvements

    International Nuclear Information System (INIS)

    Maretti Junior, Fausto; Prado Fernandes, Marcio; Oliveira, Paulo Fernando; Alves de Amorim, Valter

    1999-01-01

    The nuclear IPR-R1 TRIGA Mark I Reactor operating in the Nuclear Technology Development Center, originally Institute for Radioactive Research in Minas Gerais, Brazil, was dedicated in November 11, 1960. Initially operating for the production of radioisotopes for different uses, it started later to be used in large scale for neutron activation analysis and training of operators for nuclear power plants. Many improvements have been made throughout these years to provide a better performance in its operation and safety conditions. A new cooling system to operate until 300 kW, a new control rod mechanism, an aluminum tank for the reactor pool, an optimization in the pneumatic system, a new reactor control console and a general remodeling of the reactor laboratory were some of the improvements added. To prevent and mitigate the ageing effects, the reactor operation personnel is starting a program to minimize future operation problems. This paper describes the improvements made, the results obtained during the past 39 years, and the precautions taken to ensure future safe operation of the reactor to give operators better conditions of safe work. (author)

  7. The future of the IPR-R1 TRIGA MARK I reactor after 48 years operation

    International Nuclear Information System (INIS)

    Maretti, Fausto Junior; Sette Camara, Luiz Otavio I.; Oliveira, Paulo Fernando

    2008-01-01

    The TRIGA Mark I IPR-R1 Reactor operates in the Nuclear Technology Development Center/ Brazilian Committion for Nuclear Energy (CDTN/CNEN), originally Institute of Radioactive Researches, in Belo Horizonte, Minas Gerais, since November 6, 1960. Initially it operated for isotope production for different uses, being later used in wide scale for another purposes as analyses for activation with neutrons and training of nuclear power plants operators. Dozens of degree theses were also developed with the use of the reactor. Along the years, several improvements were introduced in the reactor and its auxiliary systems, with the purpose to provide better use of the facilities and with the objective to increase the safety in the operation. The reactor is ready right now to operate at 250 kW, and for sure the nuclear applications programmed will be improved. The Operation Manual and the Safety Analysis report were already modified, as well as the Emergency Plan and the relative procedures to the same. After the tests at the end of 2008, the reactor will already be operating in the new power. This work presents a description of the several accomplishments of the last years and comments about the possibility of new uses for the reactor in the several areas of nuclear applications and some of the experiments and tests results during the upgrading program. (authors)

  8. Thermal hydraulic and neutron kinetic coupled simulation of the IPR-R1 Triga reactor

    Energy Technology Data Exchange (ETDEWEB)

    Reis, Patricia A.L.; Costa, Antonella L.; Pereira, Claubia; Silva, Clarysson A.M. da; Veloso, Maria Auxiliadora F.; Soares, Humbero V., E-mail: patricialire@yahoo.com.br, E-mail: antonella@nuclear.ufmg.br, E-mail: claubia@nuclear.ufmg.br, E-mail: clarysson@nuclear.ufmg.br, E-mail: dora@nuclear.ufmg.br, E-mail: betovitor@ig.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Instituto Nacional de Ciencias e Tecnologia de Reatores Nucleares Inovadores (INCT/CNPq Rede), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    The nuclear industry and the scientific community have turned the attention for the development of coupled 3D neutron kinetics (NK) and thermal-hydraulic (TH) system codes to investigate specific nuclear reactor transients. Improving in theoretical investigations of complex phenomena in nuclear reactor technology have been increased thanks to numerical methods and computational resources incorporated in nuclear codes. This paper presents a model for the IPR-R1 TRIGA research reactor using the RELAP5-3D 3.0 code. The development and the assessment of the thermal-hydraulic RELAP5 code model for the IPR-R1 have been validated for steady state and transient situations and the results were published in preceding works. Results of RELAP5-3D steady state and a transient case presented in this paper show good agreement with experimental data, validating then this model for point kinetic calculations. To supply adequate cross sections to the NK code, the WIMSD5 is being used. First results of steady state calculation using the 3D neutron modeling are being presented in this paper. (author)

  9. Modernization of the CDTN IPR-R1 TRIGA reactor instrumentation and control

    International Nuclear Information System (INIS)

    Mesquita, A.Z.; Costa, A.C.L.; Souza, R.M.G.P.

    2009-01-01

    The control system of the IPR-R1 was changed in 1995. Although since the year's 80 was generalized the use of microprocessor technology and video monitors for visual interface, in the IPR-R1 control room it was used analogical system by relay-based logic, and were maintained the mechanical strip chart recorders (ink-pen drive) to measure, monitor and store the operational parameters. It was maintained the measure and the control of, practically, the same variables of the original system, although the reactor power already have been upgraded to 100 kW and began the studies to increase it to 250 kW, which is the current core configuration. For 250 kW operations the fuel heat transfer becomes important and new parameters should be used as safety operational limits. A state-of-the-art instrumentation and control system using microprocessor technology is proposed to replace the present analogical systems. The new system can eliminates most manual data logging, provides automatic or manual reactor operation modes, provides complete real-time operator display, replays historical operating data on monitor or printer, eliminates spare parts replacement problems and meets all applicable international standards as NRC and IEE specifications. This paper describes the research project in process in CDTN that has as objective the modernization of the IPR-R1 TRIGA reactor instrumentation and control of the operational variables. The project also will improve the accomplishment of neutronic and thermal-hydraulic experiments, foreseen in the CDTN research program. (author)

  10. Current utilization and long term strategy of the Finnish TRIGA research reactor FiR 1

    International Nuclear Information System (INIS)

    Auterinen, Iiro; Salmenhaara, Seppo

    2008-01-01

    FiR 1 (TRIGA Mark II, 250 kW) has an important international role in the development of boron neutron capture therapy (BNCT) for cancer. The safety and efficacy of BNCT is studied for several different cancers: - primary glioblastoma, a highly malignant brain tumour (since 1999); - recurrent glioblastoma or anaplastic astrocytoma (since 2001); - recurrent inoperable head and neck carcinoma (since 2003). It is one of the few facilities in the world providing this kind of treatments. The successes in the BNCT development have now created a demand for these treatments, although they are given on an experimental basis. Well over 100 patients treated now since May 1999: - at least 1 patient irradiation / week, often 2 (Tuesday and Thursday) - patients are referred to BNCT-treatments from several hospitals, also outside research protocols; - the hospitals pay for the treatment. The FiR 1 reactor has proven to be a reliable neutron source for the BNCT treatments; no patient irradiations have been cancelled because of a failure of the reactor. The BNCT facility has become a center of extensive academic research especially in medical physics. Nuclear education and training continue to play also a role at FiR 1 in the form of university courses and training of nuclear industry personnel. FiR 1 is one of the two sources in Scandinavia for short lived radioisotopes used in tracer studies in industry. The main isotope produced is Br-82 in the form of either KBr or ethylene bromide. Other typical isotopes are Na-24, Ar-41, La-140. The isotopes are used mainly in tracer studies in industry (Indmeas Inc., Finland). Typical activity of one irradiated Br-sample is 20 - 80 GBq; total activity produced in one year is over 3 TBq; the reactor operating time needed for the isotope production is one or two days per week. Accelerator based neutron sources are developed for BNCT. The prospect is that when BNCT will achieve a status of a fully accepted and efficient treatment modality for

  11. Experimental distribution of coolant in the IPR-R1 Triga nuclear reactor core

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Amir Z., E-mail: amir@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Servico de Tecnologia de Reatores; Palma, Daniel A.P., E-mail: dapalma@cnen.gov.b [Comissao Nacional de Energia Nuclear (CNEN/RJ), Rio de Janeiro, RJ (Brazil); Costa, Antonella L.; Pereira, Claubia; Veloso, Maria A.F.; Reis, Patricia A.L., E-mail: claubia@nuclear.ufmg.b, E-mail: dora@nuclear.ufmg.b [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear

    2011-07-01

    The IPR-R1 is a typical TRIGA Mark I light-water and open pool type reactor. The core has an annular configuration of six rings and is cooled by natural circulation. The core coolant channels extend from the bottom grid plate to the top grid plate. The cooling water flows through the holes in the bottom grid plate, passes through the lower unheated region of the element, flows upwards through the active region, passes through the upper unheated region, and finally leaves the channel through the differential area between a triangular spacer block on the top of the fuel element and a round hole in the grid. Direct measurement of the flow rate in a coolant channel is difficult because of the bulky size and low accuracy of flow meters. The flow rate through the channel may be determined indirectly from the heat balance across the channel using measurements of the water inlet and outlet temperatures. This paper presents the experiments performed in the IPR-R1 reactor to monitoring some thermo-hydraulic parameters in the core coolant channels, such as: the radial and axial temperature profile, temperature, velocity, mass flow rate, mass flux and Reynolds's number. Some results were compared with theoretical predictions, as it was expected the variables follow the power distribution (or neutron flux) in the core. (author)

  12. Experimental distribution of coolant in the IPR-R1 Triga nuclear reactor core

    International Nuclear Information System (INIS)

    Mesquita, Amir Z.; Costa, Antonella L.; Pereira, Claubia; Veloso, Maria A.F.; Reis, Patricia A.L.

    2011-01-01

    The IPR-R1 is a typical TRIGA Mark I light-water and open pool type reactor. The core has an annular configuration of six rings and is cooled by natural circulation. The core coolant channels extend from the bottom grid plate to the top grid plate. The cooling water flows through the holes in the bottom grid plate, passes through the lower unheated region of the element, flows upwards through the active region, passes through the upper unheated region, and finally leaves the channel through the differential area between a triangular spacer block on the top of the fuel element and a round hole in the grid. Direct measurement of the flow rate in a coolant channel is difficult because of the bulky size and low accuracy of flow meters. The flow rate through the channel may be determined indirectly from the heat balance across the channel using measurements of the water inlet and outlet temperatures. This paper presents the experiments performed in the IPR-R1 reactor to monitoring some thermo-hydraulic parameters in the core coolant channels, such as: the radial and axial temperature profile, temperature, velocity, mass flow rate, mass flux and Reynolds's number. Some results were compared with theoretical predictions, as it was expected the variables follow the power distribution (or neutron flux) in the core. (author)

  13. Operational parameters study of IPR-R1 TRIGA research reactor using virtual instruments

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Antonio Juscelino; Mesquita, Amir Zacarias; Lameiras, Fernando Soares, E-mail: ajp@cdtn.br, E-mail: amir@cdtn.br, E-mail: fsl@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2013-07-01

    The instrumentation of nuclear reactors is designed with the principle of reliability, redundancy and diversification of control systems. Reliable monitoring of the parameters involved in the chain reaction is of great importance regarding efficiency and operational safety of the installation. The main goal of the simulation system in this proposed paper is to provide the study and improvement in understanding how these operational variables are interrelated and their behavior especially those related to neutronic and thermohydraulics. The work will be developed using the software LabVIEW ® (Laboratory Virtual Instruments Engineering Workbench). The program will enable the study of the variables involved in the operation of the installation throughout its operating range, for instance, a few mW up to 250 kW. The IPR-R1 TRIGA is a research nuclear reactor placed in open pool and cooled by light water with natural circulation. It is located at the Nuclear Technology Development Center (CDTN), in Belo Horizonte Brazil. The developing system employs the modern concept of virtual instruments (VIs), using microprocessors and visual interface on video monitors. LabVIEW ® breaks the paradigm of text-based programming language, for programming based on icons. The system will enable the use of this reactor in training and personnel training in the nuclear field. The work follows the recommendations of the International Atomic Energy Agency (IAEA), which has encouraged its members to develop strategic plans in order to use their research reactors. (author)

  14. Operational parameters study of IPR-R1 TRIGA research reactor using virtual instruments

    International Nuclear Information System (INIS)

    Pinto, Antonio Juscelino; Mesquita, Amir Zacarias; Lameiras, Fernando Soares

    2013-01-01

    The instrumentation of nuclear reactors is designed with the principle of reliability, redundancy and diversification of control systems. Reliable monitoring of the parameters involved in the chain reaction is of great importance regarding efficiency and operational safety of the installation. The main goal of the simulation system in this proposed paper is to provide the study and improvement in understanding how these operational variables are interrelated and their behavior especially those related to neutronic and thermohydraulics. The work will be developed using the software LabVIEW ® (Laboratory Virtual Instruments Engineering Workbench). The program will enable the study of the variables involved in the operation of the installation throughout its operating range, for instance, a few mW up to 250 kW. The IPR-R1 TRIGA is a research nuclear reactor placed in open pool and cooled by light water with natural circulation. It is located at the Nuclear Technology Development Center (CDTN), in Belo Horizonte Brazil. The developing system employs the modern concept of virtual instruments (VIs), using microprocessors and visual interface on video monitors. LabVIEW ® breaks the paradigm of text-based programming language, for programming based on icons. The system will enable the use of this reactor in training and personnel training in the nuclear field. The work follows the recommendations of the International Atomic Energy Agency (IAEA), which has encouraged its members to develop strategic plans in order to use their research reactors. (author)

  15. Nuclear research reactor IEA-R1 heat exchanger inlet nozzle flow - a preliminary study

    International Nuclear Information System (INIS)

    Angelo, Gabriel; Andrade, Delvonei Alves de; Fainer, Gerson; Angelo, Edvaldo

    2009-01-01

    As a computational fluid mechanics training task, a preliminary model was developed. ANSYS-CFX R code was used in order to study the flow at the inlet nozzle of the heat exchanger of the primary circuit of the nuclear research reactor IEA-R1. The geometry of the inlet nozzle is basically compounded by a cylinder and two radial rings which are welded on the shell. When doing so there is an offset between the holes through the shell and the inlet nozzle. Since it is not standardized by TEMA, the inlet nozzle was chosen for a preliminary study of the flow. Results for the proposed model are presented and discussed. (author)

  16. Neutrons characterization of the nuclear reactor Ian-R1 of Colombia

    International Nuclear Information System (INIS)

    Gonzalez P, L. X.; Martinez O, S. A.; Vega C, H. R.

    2014-08-01

    By means of Monte Carlo methods, with the code MCNPX, the neutron characteristics of the research nuclear reactor Ian-R1 of Colombia, in power off but with the neutrons source in their start position, have been valued. The neutrons spectra, the total flow and their average power were calculated in the irradiation spaces inside the graphite reflector, as well as in the cells with air. Also the spectra, the total flow and the absorbed dose were calculated in several places distributed along the radial shaft inside the water moderator. The neutrons total flow was also considered to the long of the axial shaft. The characteristics of the neutrons spectra vary depending on their position regarding the source and the material that surrounds to the cell where the calculation was made. (Author)

  17. Evaluation of the physical protection system of the IEA-R1 research reactor

    International Nuclear Information System (INIS)

    Vaz, Antonio C.A.; Conti, Thadeu das N.

    2013-01-01

    The '09/11' in New York and the accident at the Fukushima power plant are two events that served as worldwide reference to review some aspects of the Physical Protection System (PPS) in nuclear areas. The nuclear research reactor IEA-R1 has followed this new world order and improved the protection systems that are directly related to detection (CCTV, sensors, alarms, etc), delay (turnstile, gates, barriers, etc) and response (communication systems, response force, etc), for operation against malicious act, seeking always to avoid or minimize any possibility of threat, theft and sabotage. These actions were performed to prevent and to mitigate the consequence on the environment, economy and society from damages caused by natural hazard, as well. This study evaluates the PPS of the IEA-R1 regarding the weaknesses, strengths,and impacts of the changes resulting from the system implanted. The analyses were based on methodology developed by security experts from SANDIA National Laboratories in Texas - U.S.A, allowing the evaluation of the system through probabilistic and hypothetical analysis. (author)

  18. Evaluation of the physical protection system of the IEA-R1 research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Vaz, Antonio C.A.; Conti, Thadeu das N., E-mail: acavaz@ipen.br, E-mail: tnconti@yahoo.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The '09/11' in New York and the accident at the Fukushima power plant are two events that served as worldwide reference to review some aspects of the Physical Protection System (PPS) in nuclear areas. The nuclear research reactor IEA-R1 has followed this new world order and improved the protection systems that are directly related to detection (CCTV, sensors, alarms, etc), delay (turnstile, gates, barriers, etc) and response (communication systems, response force, etc), for operation against malicious act, seeking always to avoid or minimize any possibility of threat, theft and sabotage. These actions were performed to prevent and to mitigate the consequence on the environment, economy and society from damages caused by natural hazard, as well. This study evaluates the PPS of the IEA-R1 regarding the weaknesses, strengths,and impacts of the changes resulting from the system implanted. The analyses were based on methodology developed by security experts from SANDIA National Laboratories in Texas - U.S.A, allowing the evaluation of the system through probabilistic and hypothetical analysis. (author)

  19. How the nuclear safety team conducts emergency exercises at the IEA-R1 reactor

    International Nuclear Information System (INIS)

    Vaz, Antonio C.A.; Silva, Davilson G.; Toyoda, Eduardo Y.; Santia, Paulo S.; Conti, Thadeu N.; Semmler, Renato; Carvalho, Ricardo N.

    2015-01-01

    This work introduces the Diagram of Emergency Exercise Coordination designed by the Nuclear Safety Team for better Emergency Exercise coordination. The Nuclear Safety Team was created with the mission of avoiding, preventing and mitigating the causes and effects of accidents at the IEA-R1. The facility where we conduct our work is located in an area of a huge population, what increases the responsibility of our mission: conducting exercises and training are part of our daily activities. During the Emergency Exercise, accidents ranked 0-4 on INES (International Nuclear Events Scale) are simulated and involve: Police Department, Fire Department, workers, people from the community, and others. In the last exercise held in June 2014, the scenario contemplated a terrorist organization action that infiltrated in a group of students who were visiting the IEA-R1, tried to steal fresh fuel element to fabricate a dirty bomb. Emergency procedures and plans, timeline and metrics of the actions were applied to the Emergency Exercise evaluation. The next exercise will be held in November, with the simulation of the piping of the primary cooling circuit rupture, causing the emptying of the pool and the lack of cooling of the fuel elements in the reactor core: this will be the scenario. The skills acquired and the systems improvement have been very important tools for the reactor operation safety and the Nuclear Safety Team is making technical efforts so that these Emergency Exercises may be applied to other nuclear and radiological facilities. Equally important for the process of improving nuclear safety is the emphasis placed on implementing quality improvements to the human factor in the nuclear safety area, a crucial element that is often not considered by those outside the nuclear sector. Surely, the Diagram of Emergency Exercise Coordination application will improve and facilitate the organization, coordination and evaluation tasks. (author)

  20. How the nuclear safety team conducts emergency exercises at the IEA-R1 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Vaz, Antonio C.A.; Silva, Davilson G.; Toyoda, Eduardo Y.; Santia, Paulo S.; Conti, Thadeu N.; Semmler, Renato; Carvalho, Ricardo N., E-mail: acavaz@ipen.br, E-mail: dgsilva@ipen.br, E-mail: eytoyoda@ipen.br, E-mail: psantia@ipen.br, E-mail: tnconti@ipen.br, E-mail: rsemmler@ipen.b, E-mail: rncarval@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    This work introduces the Diagram of Emergency Exercise Coordination designed by the Nuclear Safety Team for better Emergency Exercise coordination. The Nuclear Safety Team was created with the mission of avoiding, preventing and mitigating the causes and effects of accidents at the IEA-R1. The facility where we conduct our work is located in an area of a huge population, what increases the responsibility of our mission: conducting exercises and training are part of our daily activities. During the Emergency Exercise, accidents ranked 0-4 on INES (International Nuclear Events Scale) are simulated and involve: Police Department, Fire Department, workers, people from the community, and others. In the last exercise held in June 2014, the scenario contemplated a terrorist organization action that infiltrated in a group of students who were visiting the IEA-R1, tried to steal fresh fuel element to fabricate a dirty bomb. Emergency procedures and plans, timeline and metrics of the actions were applied to the Emergency Exercise evaluation. The next exercise will be held in November, with the simulation of the piping of the primary cooling circuit rupture, causing the emptying of the pool and the lack of cooling of the fuel elements in the reactor core: this will be the scenario. The skills acquired and the systems improvement have been very important tools for the reactor operation safety and the Nuclear Safety Team is making technical efforts so that these Emergency Exercises may be applied to other nuclear and radiological facilities. Equally important for the process of improving nuclear safety is the emphasis placed on implementing quality improvements to the human factor in the nuclear safety area, a crucial element that is often not considered by those outside the nuclear sector. Surely, the Diagram of Emergency Exercise Coordination application will improve and facilitate the organization, coordination and evaluation tasks. (author)

  1. Characterization of cartridge filters from the IEA-R1 Nuclear Reactor

    International Nuclear Information System (INIS)

    2015-01-01

    The management of radioactive waste ensures safety to human health and the environment nowadays and for the future, without overwhelming the upcoming generations. The primary characterization of radioactive waste is one of the main steps in the management of radioactive waste. This step permits to choose the best treatment for the radioactive waste before forwarding it to its final disposal. The aim of the present work is the primary characterization of cartridge filters from the IEA-R1 nuclear reactor utilizing gamma-ray spectrometry, and the method of Monte Carlo for calibration. The IEA-R1 is located in the Nuclear and Energy Research Institute (IPEN - CNEN) in the city of Sao Paulo, Brazil. Cartridge filters are used for purification of the cooling water that is pumped through the core of the pool type nuclear research reactors. Once worn out, these filters are replaced and then become radioactive waste. Determination of the radioactive inventory is of paramount importance in the management of such radioactive waste, and one of the main methods for doing so is the gamma-ray spectrometry, which can identify and quantify high energy photon emitters. The technique chosen for the characterization of radioactive waste in the present work is the gamma-ray spectrometry with High purity Germanium (HPGe) detectors. From the energy identified in the experimental spectrum, three radioisotopes were identified in the cartridge filter: 108m Ag, 110m Ag, 60 Co. For the estimated activity of the filter, the calibration in efficiency was made utilizing the MCNP4C code of the Monte Carlo method. Such method was chosen because there is no standard source available in the same geometry of the cartridge filter, therefore a simulation had to be developed in order to reach a calibration equation, necessary to estimate the activity of the radioactive waste. The results presented an activity value in the order of MBq for all radioisotopes. (authors)

  2. Characterization of cartridge filters from the IEA-R1 Nuclear Reactor

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-07-01

    The management of radioactive waste ensures safety to human health and the environment nowadays and for the future, without overwhelming the upcoming generations. The primary characterization of radioactive waste is one of the main steps in the management of radioactive waste. This step permits to choose the best treatment for the radioactive waste before forwarding it to its final disposal. The aim of the present work is the primary characterization of cartridge filters from the IEA-R1 nuclear reactor utilizing gamma-ray spectrometry, and the method of Monte Carlo for calibration. The IEA-R1 is located in the Nuclear and Energy Research Institute (IPEN - CNEN) in the city of Sao Paulo, Brazil. Cartridge filters are used for purification of the cooling water that is pumped through the core of the pool type nuclear research reactors. Once worn out, these filters are replaced and then become radioactive waste. Determination of the radioactive inventory is of paramount importance in the management of such radioactive waste, and one of the main methods for doing so is the gamma-ray spectrometry, which can identify and quantify high energy photon emitters. The technique chosen for the characterization of radioactive waste in the present work is the gamma-ray spectrometry with High purity Germanium (HPGe) detectors. From the energy identified in the experimental spectrum, three radioisotopes were identified in the cartridge filter: {sup 108m}Ag, {sup 110m}Ag, {sup 60}Co. For the estimated activity of the filter, the calibration in efficiency was made utilizing the MCNP4C code of the Monte Carlo method. Such method was chosen because there is no standard source available in the same geometry of the cartridge filter, therefore a simulation had to be developed in order to reach a calibration equation, necessary to estimate the activity of the radioactive waste. The results presented an activity value in the order of MBq for all radioisotopes. (authors)

  3. Summary of IEA-R1 research a reactor licensing related to its power increase from 2 to 10 MW

    International Nuclear Information System (INIS)

    1989-04-01

    This work is a summary of IEA-R1 research reactor licensing related to its power increase from 2 to 10 MW. It reports also safety requirements, fuel elements, and reactor control modifications inherent to power increase. (A.C.A.S.)

  4. Modifications in the operational conditions of the IEA-R1 reactor under continuous 48 hours operation

    International Nuclear Information System (INIS)

    Moreira, Joao Manoel Losada; Frajndlich, Roberto

    1995-01-01

    This work shows the required changes in the IEA-R1 reactor for operation at 2 Mw, 48 hours continuously. The principal technical change regards the operating conditions of the reactor, namely, the required excess reactivity which now will amount to 4800 pcm in order to compensate the Xe poisoning at equilibrium at 2 Mw. (author). 6 refs, 1 fig, 1 tab

  5. Simulation of channel blockage for the IEA-R1 research reactor using RELAP/MOD 3

    International Nuclear Information System (INIS)

    Oliveira, Eduardo C.F. de; Castrillo, Lazara Silveira

    2015-01-01

    Research reactors have great importance in the area of nuclear technology, such as radioisotope production, research in nuclear physics, development of new technologies and staff training for reactor operation. The IEA-R1 is a Brazilian research reactor type pool, located at the IPEN (Instituto de Pesquisas Energeticas e Nucleares). In this work is simulated with computer code RELAP5 / MOD 3.3.2 gamma, the effect caused by partial and complete blockage of a channel in MTR fuel element of the IEA-R1 core, in order to analyzed the thermal hydraulic parameters on adjacent channels. (author)

  6. Simulation of channel blockage for the IEA-R1 research reactor using RELAP/MOD 3

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Eduardo C.F. de; Castrillo, Lazara Silveira, E-mail: ecfoliveira@hotmail.com, E-mail: lazara.castrillo@upe.br [Universidade de Pernambuco (UPE), Recife, PE (Brazil). Escola Politecnica de Pernambuco

    2015-07-01

    Research reactors have great importance in the area of nuclear technology, such as radioisotope production, research in nuclear physics, development of new technologies and staff training for reactor operation. The IEA-R1 is a Brazilian research reactor type pool, located at the IPEN (Instituto de Pesquisas Energeticas e Nucleares). In this work is simulated with computer code RELAP5 / MOD 3.3.2 gamma, the effect caused by partial and complete blockage of a channel in MTR fuel element of the IEA-R1 core, in order to analyzed the thermal hydraulic parameters on adjacent channels. (author)

  7. Water chemical control of the TRIGA IPR-R1 reactor primary cooling system

    International Nuclear Information System (INIS)

    Auler, Lucia M.L.A; Chaves, Renata D.A.; Palmieri, Helena E.L.; Menezes, Maria Angela de B.C.; Oliveira, Paulo F.; Kastner, Geraldo F.; Damazio, Ilza; Fagundes, Oliene dos R.; Cintra, Maria Olivia C.; Andrade, Geraldo V. de; Amaral, Angela M.; Franco, Milton B.; Fortes, Flavio; Gomes, Nilton Carlos; Vidal, Andrea; Maretti Junior, Fausto; Knupp, Eliana A.N.; Souza, Wagner de; Guedes, Joao B.; Furtado, Renato C.S.

    2013-01-01

    The TRIGA Mark I IPR-R1 reactor located at CDTN/CNEN has been in operation and contributed to research and with services to society since 1960. Is has been used in several activities such as nuclear power plant operation, graduate and post-graduate training courses, isotope production, and as an analytical irradiation tool of different types of samples. Among the several structural and operational safety requirements is the chemical quality control of the primary circuit cooling water. The aim of this work was to check the cooling water quality from the pool reactor. A water sampling plan was proposed (May, 2011 - June, 2012) and presents the results obtained in this period. The natural radioactivity level as gross alpha and gross beta activity and other chemical parameters (pH and electric conductivity) of the samples were analyzed. Some instrumental techniques were used: potentiometric methods (pH), conductometric methods (electrical conductivity, EC) and gross α and gross β proportional counting system). (author)

  8. Experience on wet storage spent fuel sipping at IEA-R1 Brazilian research reactor

    International Nuclear Information System (INIS)

    Perrotta, J.A.; Terremoto, L.A.A.; Zeituni, C.A.

    1998-01-01

    The IEA-R1 research reactor of the Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP) is a pool type reactor of B and W design, that has been operating since 1957 at a power of 2 MW. Irradiated (spent) fuels have been stored at the facility during the various years of operation. At present there are 40 spent fuel assemblies at dry storage, 79 spent fuel assemblies at wet storage and 30 fuel assemblies in the core. The oldest fuels are of United States origin, made with U-Al alloy, both of LEU and HEU MTR fuel type. Many of these fuel assemblies have corrosion pits along their lateral fuel plates. These pits originate by galvanic corrosion between the fuel plate and the stainless steel storage racks. As a consequence of the possibility of sending the irradiated old fuels back the U.S.A., sipping tests were performed with the spent fuel assemblies. The reason for this was to evaluate their 137 Cs leaking rate, if any. This work describes the procedure and methodology used to perform the sipping tests with the fuel assemblies at the storage pool, and presents the results obtained for the 137 Cs sipping water activity for each fuel assembly. A correlation is made between the corrosion pits and the activity values measured. A 137 Cs leaking rate is determined and compared to the criteria established for canning spent fuel assemblies before shipment

  9. Improvements at the biological shielding of BNCT research facility in the IEA-R1 reactor

    International Nuclear Information System (INIS)

    Souza, Gregorio Soares de

    2011-01-01

    The technique of neutron capture in boron is a promising technique in cancer treatment, it uses the high LET particles from the reaction 10 B (n, α) 7 Li to destroy cancer cells.The development of this technique began in the mid-'50s and even today it is the object of study and research in various centers around the world, Brazil has built a facility that aims to conduct research in BNCT, this facility is located next to irradiation channel number three at the research nuclear reactor IEA-R1 and has a biological shielding designed to meet the radiation protection standards. This biological shielding was developed to allow them to conduct experiments with the reactor at maximum power, so it is not necessary to turn on and off the reactor to irradiate samples. However, when the channel is opened for experiments the background radiation in the experiments salon increases and this background variation makes it impossible to perform measurements in a neutron diffraction research that utilizes the irradiation channel number six. This study aims to further improve the shielding in order to minimize the variation of background making it possible to perform the research facility in BNCT without interfering with the action of the research group of the irradiation channel number six. To reach this purpose, the code MCNP5, dosimeters and activation detectors were used to plan improvements in the biological shielding. It was calculated with the help of the code an improvement that can reduce the average heat flow in 71.2% ± 13 and verified experimentally a mean reduce of 70 ± 9% in dose due to thermal neutrons. (author)

  10. Insertion of reactivity (RIA) without scram in the reactor core IEA-R1 using code PARET

    International Nuclear Information System (INIS)

    Alves, Urias F.; Castrillo, Lazara S.; Lima, Fernando A.

    2013-01-01

    The modeling and analysis thermo hydraulics of a research reactor with MTR type fuel elements - Material Testing Reactor - was performed using the code PARET (Program for the Analysis of Reactor Transients) when in the system some external event is introduced that changed the reactivity in the reactor core. Transients of Reactivity Insertion of 0.5 , 1.5 and 2.0$/ 0.7s in the brazilian reactor IEA-R1 will be presented, and will be shown under what conditions it is possible to ensure the safe operation of its nucleus. (author)

  11. New digital control system for the operation of the Colombian research reactor IAN-R1; Nuevo sistema de control digital para la operacion del reactor de investigacion Colombiano IAN-R1

    Energy Technology Data Exchange (ETDEWEB)

    Celis del A, L.; Rivero, T.; Bucio, F.; Ramirez, R.; Segovia, A.; Palacios, J., E-mail: lina.celis@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2015-09-15

    En 2011, Mexico won the Colombian international tender for the renewal of instrumentation and control of the IAN-R1 Reactor, to Argentina and the United States. This paper presents the design criteria and the development made for the new digital control system installed in the Colombian nuclear reactor IAN-R1, which is based on a redundant and diverse architecture, which provides increased availability, reliability and safety in the reactor operation. This control system and associated instrumentation met all national export requirements, with the safety requirements established by the IAEA as well as the requirements demanded by the Colombian Regulatory Body in nuclear matter. On August 20, 2012, the Colombian IAN-R1 reactor reached its first criticality controlled with the new system developed at Instituto Nacional de Investigaciones Nucleares (ININ). On September 14, 2012, the new control system of the Colombian IAN-R1 reactor was officially handed over to the Colombian authorities, this being the first time that Mexico exported nuclear technology through the ININ. Currently the reactor is operating successfully with the new control system, and has an operating license for 5 years. (Author)

  12. Evaluation of power behavior during startup and shutdown procedures of the IPR-R1 Triga Reactor

    International Nuclear Information System (INIS)

    Zangirolami, Dante M.; Mesquita, Amir Z.; Ferreira, Andrea V.

    2009-01-01

    The IPR-R1 nuclear reactor of Centro de Desenvolvimento da Tecnologia Nuclear - CDTN/CNEN is a TRIGA Mark I pool type reactor cooled by natural circulation of light water. In the IPR-R1, the power is measured by four nuclear channels, neutron-sensitive chambers, which are mounted around the reactor core: the Startup Channel for power indication during reactor startup; the Logarithmic Wide Range Power Monitoring Channel; the Linear Multi-Range Power Monitoring Channel and the Percent Power Safety Channel. A data acquisition system automatically does the monitoring and storage of all the reactor operational parameters including the reactor power. The startup procedure is manual and the time to reach the desired reactor power level is different on each irradiation which may introduces differences in induced activity of samples irradiated in different irradiations. In this work, the power evolution during startup and shutdown periods of IPR-R1 operation was evaluated and the mean values of reactor energy production in these operational phases were obtained. The analyses were performed on basis of the Linear Multi-Range Channel data. The results show that the sum of startup and shutdown periods corresponds to 1% of released energy for irradiations during 1h at 100kW. This value may be useful to correct experimental data in neutron activation experiments. (author)

  13. Characterization of filter cartridges from the IEA-R1 reactor by radiochemical method

    International Nuclear Information System (INIS)

    Geraldo, Bianca; Vicente, Roberto; Ferreira, Robson J.; Goes, Marcos M.; Marumo, Julio T.

    2015-01-01

    The filter cartridges used in water purification system of research nuclear reactor IEA-R1 are considered radioactive wastes after their useful life. The characterization of these wastes is one of the stages of management, which aims to identify and quantify the radionuclides present, including those known as 'difficult to measure' (DTM) radionuclides. Establish a radiochemical analysis methodology for this type of waste is a difficult job, not only by the application of these techniques, but also by the amount of radionuclides that should be analyzed. In the waste produced in a nuclear reactor, the most important radionuclides are fission products, activation products and transuranic elements. Since these radionuclides emit gamma radiation not measurable in its decay process and consequently are difficult to measure, their concentrations can be estimated by indirect methods such as scale factors. This method is used to evaluate the DTM concentration, which is represented by alpha and beta nuclides using the correlation between them and the radionuclide key, a gamma emitter. The objective of this work is to describe a radiochemical analysis methodology for gamma emitter nuclides, present in the filter cartridges, evaluating the activity and concentrations by destructive assays. At the same time, two studies have been performed by non-destructive assays, the first one based on dose rates and the point kernel method to correlate the results and the second one based on calibration efficiency with Monte Carlo method. These studies belong to the radioactive waste characterization program that has been conducted at the Waste Management Laboratory of Nuclear and Energy Research Institute, IPEN-CNEN/SP. (author)

  14. Characterization of filter cartridges from the IEA-R1 reactor by radiochemical method

    Energy Technology Data Exchange (ETDEWEB)

    Geraldo, Bianca; Vicente, Roberto; Ferreira, Robson J.; Goes, Marcos M.; Marumo, Julio T., E-mail: bgeraldo@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    The filter cartridges used in water purification system of research nuclear reactor IEA-R1 are considered radioactive wastes after their useful life. The characterization of these wastes is one of the stages of management, which aims to identify and quantify the radionuclides present, including those known as 'difficult to measure' (DTM) radionuclides. Establish a radiochemical analysis methodology for this type of waste is a difficult job, not only by the application of these techniques, but also by the amount of radionuclides that should be analyzed. In the waste produced in a nuclear reactor, the most important radionuclides are fission products, activation products and transuranic elements. Since these radionuclides emit gamma radiation not measurable in its decay process and consequently are difficult to measure, their concentrations can be estimated by indirect methods such as scale factors. This method is used to evaluate the DTM concentration, which is represented by alpha and beta nuclides using the correlation between them and the radionuclide key, a gamma emitter. The objective of this work is to describe a radiochemical analysis methodology for gamma emitter nuclides, present in the filter cartridges, evaluating the activity and concentrations by destructive assays. At the same time, two studies have been performed by non-destructive assays, the first one based on dose rates and the point kernel method to correlate the results and the second one based on calibration efficiency with Monte Carlo method. These studies belong to the radioactive waste characterization program that has been conducted at the Waste Management Laboratory of Nuclear and Energy Research Institute, IPEN-CNEN/SP. (author)

  15. Feasibility study of application of Prompt Gamma Neutron Activation Analysis (PGNAA) method in TRIGA IPR-R1 reactor

    International Nuclear Information System (INIS)

    Guerra, Bruno Teixeira

    2016-01-01

    The TRIGA Mark I IPR-R1 research reactor is located at Nuclear Technology Development Centre (CDTN), Brazilian Commission for Nuclear Energy (CNEN), in Belo Horizonte, Brazil. The reactor operates at 100 kW but the core configuration allows the increasing of the power up to 250 kW. It has been applied research, training and radioisotopes production. The establishment of the Prompt Gamma Neutron Activation Analysis (PGNAA) method at the TRIGA IPR-R1 reactor will significantly increase the types of matrices analysed as well as the number of chemical elements. Additionally it will complement the neutron activation analysis. This work presents a proposed design of a PGNAA facility to be installed at the TRIGA IPR-R1. The proposed design is based on a tube as a neutron guide from the reactor core, inside the reactor pool, 6 m below the room’s level where shall be located the rack containing the set sample/detector/shielding. Thus, the aim of this study is to verify the feasibility to establish the PGNAA method in IPR-R1 through theoretical study applying the Monte Carlo code. The feasibility of establishing the PGAA method at the IPR-R1 installations was evaluated through of the calculations of neutron flux, radioactive capture reaction rates and detection limits for some isotopes. According to the obtained results, it can be concluded that is possible to establish the PGAA method at the IPR-R1 reactor, even with some restrictions in its theoretical design calculated by MCNP. (author)

  16. Optimization of the irradiation beam in the BNCT research facility at IEA-R1 reactor

    International Nuclear Information System (INIS)

    Castro, Vinicius Alexandre de

    2014-01-01

    Boron Neutron Capture Therapy (BNCT) is a radiotherapeutic technique for the treatment of some types of cancer whose useful energy comes from a nuclear reaction that occurs when thermal neutron impinges upon a Boron-10 atom. In Brazil there is a research facility built along the beam hole number 3 of the IEA-R1 research reactor at IPEN, which was designed to perform BNCT research experiments. For a good performance of the technique, the irradiation beam should be mostly composed of thermal neutrons with a minimum as possible gamma and above thermal neutron components. This work aims to monitor and evaluate the irradiation beam on the sample irradiation position through the use of activation detectors (activation foils) and also to propose, through simulation using the radiation transport code, MCNP, new sets of moderators and filters which shall deliver better irradiation fields at the irradiation sample position In this work, a simulation methodology, based on a MCNP card, known as wwg (weight window generation) was studied, and the neutron energy spectrum has been experimentally discriminated at 5 energy ranges by using a new set o activation foils. It also has been concluded that the BNCT research facility has the required thermal neutron flux to perform studies in the area and it has a great potential for improvement for tailoring the irradiation field. (author)

  17. Real-time neutron radiography at the Iea-R1 m nuclear research reactor

    International Nuclear Information System (INIS)

    Menezes, M.O. de; Pugliesi, R.; Pereira, M.A.S.; Andrade, M.L.G.

    2003-01-01

    A LIXI (Light Intensifier X-ray Image) device has been employed in a real-time neutron radiography system. The LIXI is coupled to a video camera and the real-time images can be observed in a TV monitor, and processed in a computer. In order to get the real-time system operational, the neutron radiography facility installed at the IEA-R1 m nuclear research reactor of the IPEN-CNEN/S P has been optimized. The most important improvements were the neutron/gamma ratio, the effective energy of the neutron beam, decrease of the scattered radiation at the irradiation position, and the additional shielding of the video camera. Several one-frame as well as computer processed images are presented. The overall Modulation Transfer Function for the real-time system was obtained from the resolution parameter p = 0:44 +- 0:04 mm; the system sensitivity, evaluated for a Perspex step wedge, was determined and the average value is 0:70 +- 0:09 mm. (author)

  18. IEA-R1 Nuclear Research Reactor: 58 Years of Operating Experience and Utilization for Research, Teaching and Radioisotopes Production

    Energy Technology Data Exchange (ETDEWEB)

    Cardenas, Jose Patricio Nahuel; Filho, Tufic Madi; Saxena, Rajendra; Filho, Walter Ricci [Nuclear and Energy Research Institute, IPEN-CNEN/SP, Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP, Av. Prof. Lineu Prestes 2242 Cid Universitaria CEP: 05508-000- Sao Paulo-SP (Brazil)

    2015-07-01

    IEA-R1 research reactor at the Instituto de Pesquisas Energeticas e Nucleares (Nuclear and Energy Research Institute) IPEN, Sao Paulo, Brazil is the largest power research reactor in Brazil, with a maximum power rating of 5 MWth. It is being used for basic and applied research in the nuclear and neutron related sciences, for the production of radioisotopes for medical and industrial applications, and for providing services of neutron activation analysis, real time neutron radiography, and neutron transmutation doping of silicon. IEA-R1 is a swimming pool reactor, with light water as the coolant and moderator, and graphite and beryllium as reflectors. The reactor was commissioned on September 16, 1957 and achieved its first criticality. It is currently operating at 4.5 MWth with a 60-hour cycle per week. In the early sixties, IPEN produced {sup 131}I, {sup 32}P, {sup 198}Au, {sup 24}Na, {sup 35}S, {sup 51}Cr and labeled compounds for medical use. During the past several years, a concerted effort has been made in order to upgrade the reactor power to 5 MWth through refurbishment and modernization programs. One of the reasons for this decision was to produce {sup 99}Mo at IPEN. The reactor cycle will be gradually increased to 120 hours per week continuous operation. It is anticipated that these programs will assure the safe and sustainable operation of the IEA-R1 reactor for several more years, to produce important primary radioisotopes {sup 99}Mo, {sup 125}I, {sup 131}I, {sup 153}Sm and {sup 192}Ir. Currently, all aspects of dealing with fuel element fabrication, fuel transportation, isotope processing, and spent fuel storage are handled by IPEN at the site. The reactor modernization program is slated for completion by 2015. This paper describes 58 years of operating experience and utilization of the IEA-R1 research reactor for research, teaching and radioisotopes production. (authors)

  19. Study of neutronic flux in IPR-R1 reactor with MCNPX; Estudo do fluxo neutronico no reator IPR-R1 com o MCNPX

    Energy Technology Data Exchange (ETDEWEB)

    Melo, J.A.S.; Castrillo, L.S., E-mail: julio.angelo@poli.br, E-mail: lazara@poli.br [Universidade de Pernambuco (UPE), Recife, PE (Brazil). Escola Politecnica; Oliveira, R.M.B.M., E-mail: romero.matias@educacao.pe.gov.br [Secretaria Executiva de Educacao do Estado de Pernambuco (SEE), Recife, PE (Brazil)

    2016-11-01

    MCNPX computer code, one of the latest versions of code MCNP transport were used to study the flux distribution and its neutronic fluence as a function of energy in two research reactor irradiation IPR-R1. The model developed was validated with research conducted by Dalle (2005). Initially, in the simulation is considered fresh fuel whose core configuration contained three neutron rods control, being two of them 100% ejected while the other inserted 3,1 x 10{sup -1} m deep, as adopted in the literature situation. The neutron source used was the critical type, through KSRC card. The results of the neutron flow and neutronic fluence were obtained in the central tube and the turntable on a range of energy spectrum that ranged from 1.0 x 10{sup -9} MeV to 10 MeV, showing good correlations with the model used in validation. Finally, a hypothetical situation wherein the three reactor control rods are ejected simultaneously was simulated. The simulation results showed an increase in the neutron flux of 7% in the central tube and 5% on the turntable.

  20. Thermal hydraulic analysis of the IPR-R1 TRIGA research reactor using a RELAP5 model

    International Nuclear Information System (INIS)

    Costa, Antonella L.; Reis, Patricia Amelia L.; Pereira, Claubia; Veloso, Maria Auxiliadora F.; Mesquita, Amir Z.; Soares, Humberto V.

    2010-01-01

    The RELAP5 code is widely used for thermal hydraulic studies of commercial nuclear power plants. Current investigations and code adaptations have demonstrated that the RELAP5 code can be also applied for thermal hydraulic analysis of nuclear research reactors with good predictions. Therefore, as a contribution to the assessment of RELAP5/MOD3.3 for research reactors analysis, this work presents steady-state and transient calculation results performed using a RELAP5 model to simulate the IPR-R1 TRIGA research reactor at 50 kilowatts (kW) of power operation. The reactor is located in the Nuclear Technology Development Center (CDTN), Brazil. It is a 250 kW, light water moderated and cooled, graphite-reflected, open pool type research reactor. The development and the assessment of a RELAP5 model for the IPR-R1 TRIGA are presented. Experimental data were considered in the process of the RELAP5 model validation. The RELAP5 results were also compared with calculated data from the STHIRP-1 (Research Reactors Thermal Hydraulic Simulation) code. The results obtained have shown that the RELAP5 model for the IPR-R1 TRIGA reproduces the actual steady-state reactor behavior in good agreement with the available data.

  1. Supervisory system to monitor the neutron flux of the IPR-R1 TRIGA research reactor at CDTN

    International Nuclear Information System (INIS)

    Pinto, Antonio Juscelino; Mesquita, Amir Zacarias; Tello, Cledola Cassia Oliveira

    2009-01-01

    The IPR-R1 TRIGA Mark I nuclear research reactor at the Nuclear Technology Development Center - CDTN (Belo Horizonte) is a pool type reactor. It was designed for research, training and radioisotope production. The International Atomic Energy Agency- IAEA - recommends the use of friendly interfaces for monitoring and controlling the operational parameters of nuclear reactors. This paper reports the activities for implementing a supervisory system, using LabVIEW software, with the purpose to provide the IPR-R1 TRIGA research reactor with a modern, safe and reliable system to monitor the time evolution of the power of its core. The use of the LabVIEW will introduce modern techniques, based on electronic processor and visual interface in video monitor, substituting the mechanical strip chart recorders (ink-pen drive and paper) that monitor the current neutrons flux, which is proportional to the thermal power supplied by reactor core. The main objective of the system will be to follow the evolution of the neutronic flux originated in the Linear and Logarithmic channels. A great advantage of the supervisory software nowadays, in relation to computer programs currently used in the facility, is the existence of new resources such as the data transmission and graphical interfaces by net, grid lines display in the graphs, and resources for real time reactor core video recordings. The considered system could also in the future be optimized, not only for data acquisition, but also for the total control of IPR-R1 TRIGA reactor(author)

  2. Neutron field characterization in the installation for BNCT study in the IEA-R1 reactor

    International Nuclear Information System (INIS)

    Carneiro Junior, Valdeci

    2008-01-01

    This work aims to characterize the mixed neutron and gamma field, in the sample irradiation position, in a research installation for Boron Neutron Capture Therapy (BNCT), in the IPEN IEA-R1 reactor. The BNCT technique has been studied as a safe and selective option in the treatment of resistant cancerigenous tumors or considered non-curable by the conventional techniques, for example, the Glioblastoma Multiform - a brain cancerigenous tumor. Neutron flux measurements were carried out: thermal, resonance and fast, as well as neutron and gamma rays doses, in the sample position, using activation foils detectors and thermoluminescent dosimeters. For the determination of the neutron spectrum and intensity, a set of different threshold activation foils and gold foils covered and uncovered with cadmium irradiated in the installation was used, analyzed by a high Pure Germanium semiconductor detector, coupled to an electronic system suitable for gamma spectrometry. The results were processed with the SAND-BP code. The doses due to gamma and neutron rays were determined using thermoluminescent dosimeters TLD 400 and TLD 700 sensitive to gamma and TLD 600, sensitive to neutrons. The TLDs were selected and used for obtaining the calibration curves - dosimeter answer versus dose - from each of the TLD three types, which were necessary to calculate the doses due to neutron and gamma, in the sample position. The radiation field, in the sample irradiation position, was characterized flux for thermal neutrons of 1.39.10 8 ± 0,12.10 8 n/cm 2 s the doses due to thermal neutrons are three times higher than those due to gamma radiation and confirm the reproducibility and consistency of the experimental findings obtained. Considering these results, the neutron field and gamma radiation showed to be appropriated for research in BNCT. (author)

  3. Circuits design of action logics of the protection system of nuclear reactor IAN-R1 of Colombia; Diseno de los circuitos de la logica de actuacion del sistema de proteccion del reactor nuclear IAN-R1 de Colombia

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez M, J. L.; Rivero G, T.; Sainz M, E., E-mail: joseluis.gonzalez@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2014-10-15

    Due to the obsolescence of the instrumentation and control system of the nuclear research reactor IAN-R1, the Institute of Geology and Mining of Colombia, IngeoMinas, launched an international convoking for renewal it which was won by the Instituto Nacional de Investigaciones Nucleares (ININ). Within systems to design, the reactor protection system is described as important for safety, because this carried out, among others two primary functions: 1) ensuring the reactor shutdown safely, and 2) controlling the interlocks to protect against operational errors if defined conditions have not been met. To fulfill these functions, the various subsystems related to the safety report the state in which they are using binary signals and are connected to the inputs of two redundant logic wiring circuits called action logics (Al) that are part of the reactor protection system. These Al also serve as logical interface to indicate at all times the status of subsystems, both the operator and other systems. In the event that any of the subsystems indicates a state of insecurity in the reactor, the Al generate signals off (or scram) of the reactor, maintaining the interlock until the operator sends a reset signal. In this paper the design, implementation, verification and testing of circuits that make up the Al 1 and 2 of IAN-R1 reactor is described, considering the fulfillment of the requirements that the different international standards imposed on this type of design. (Author)

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

    International Nuclear Information System (INIS)

    Toyoda, Eduardo Yoshio; Gordon, Ana Maria Pinho Leite; Sordi, Gian-Maria A.A.

    2001-01-01

    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. Reliability database of IEA-R1 Brazilian research reactor: Applications to the improvement of installation safety

    International Nuclear Information System (INIS)

    Oliveira, P.S.P.; Tondin, J.B.M.; Martins, M.O.; Yovanovich, M.; Ricci Filho, W.

    2010-01-01

    In this paper the main features of the reliability database being developed at Ipen-Cnen/SP for IEA-R1 reactor are briefly described. Besides that, the process for collection and updating of data regarding operation, failure and maintenance of IEA-R1 reactor components is presented. These activities have been conducted by the reactor personnel under the supervision of specialists in Probabilistic Safety Analysis (PSA). The compilation of data and subsequent calculation are based on the procedures defined during an IAEA Coordinated Research Project which Brazil took part in the period from 2001 to 2004. In addition to component reliability data, the database stores data on accident initiating events and human errors. Furthermore, this work discusses the experience acquired through the development of the reliability database covering aspects like improvements in the reactor records as well as the application of the results to the optimization of operation and maintenance procedures and to the PSA carried out for IEA-R1 reactor. (author)

  6. Circuits design of action logics of the protection system of nuclear reactor IAN-R1 of Colombia

    International Nuclear Information System (INIS)

    Gonzalez M, J. L.; Rivero G, T.; Sainz M, E.

    2014-10-01

    Due to the obsolescence of the instrumentation and control system of the nuclear research reactor IAN-R1, the Institute of Geology and Mining of Colombia, IngeoMinas, launched an international convoking for renewal it which was won by the Instituto Nacional de Investigaciones Nucleares (ININ). Within systems to design, the reactor protection system is described as important for safety, because this carried out, among others two primary functions: 1) ensuring the reactor shutdown safely, and 2) controlling the interlocks to protect against operational errors if defined conditions have not been met. To fulfill these functions, the various subsystems related to the safety report the state in which they are using binary signals and are connected to the inputs of two redundant logic wiring circuits called action logics (Al) that are part of the reactor protection system. These Al also serve as logical interface to indicate at all times the status of subsystems, both the operator and other systems. In the event that any of the subsystems indicates a state of insecurity in the reactor, the Al generate signals off (or scram) of the reactor, maintaining the interlock until the operator sends a reset signal. In this paper the design, implementation, verification and testing of circuits that make up the Al 1 and 2 of IAN-R1 reactor is described, considering the fulfillment of the requirements that the different international standards imposed on this type of design. (Author)

  7. Ageing implementation and refurbishment development at the IEA-R1 nuclear research reactor: a 15 years experience

    International Nuclear Information System (INIS)

    Cardenas, Jose Patricio N.; Ricci Filho, Walter; Carvalho, Marcos R. de; Berretta, Jose Roberto; Marra Neto, Adolfo

    2011-01-01

    IPEN (Instituto de Pesquisas Energeticas e Nucleares) is a nuclear research center established into the Secretary of Science and Technology from the government of the state of Sao Paulo, and administered both technically and financially by Comissao Nacional de Energia Nuclear (CNEN), a federal government organization under the Ministry of Science and Technology. The institute is located inside the campus of the University of Sao Paulo, Sao Paulo city, Brazil. One of major nuclear facilities at IPEN is the IEA-R1 nuclear research reactor. It is the unique Brazilian research reactor with substantial power level suitable for application with research in physics, chemistry, biology and engineering, as well as radioisotope production for medical and other applications. Designed and built by Babcok-Wilcox, in accordance with technical specifications established by the Brazilian Nuclear Energy Commission, and financed by the US Atoms for Peace Program, it is a swimming pool type reactor, moderated and cooled by light water and uses graphite and beryllium as reflector elements. The first criticality was achieved on September 16, 1957 and the reactor is currently operating at 4.0 MW on a 64h per week cycle. Since 1996, an IEA-R1 reactor ageing study was established at the Research Reactor Center (CRPq) related with general deterioration of components belonging to some operational systems, as cooling towers from secondary cooling system, piping and pumps, sample irradiation devices, radiation monitoring system, fuel elements, rod drive mechanisms, nuclear and process instrumentation and safety operational system. Although basic structures are almost the same as the original design, several improvements and modifications in components, systems and structures had been made along reactor life. This work aims to show the development of the ageing program in the IEA-R1 reactor and the upgrading (modernization) that was carried out, concerning several equipment and system in the

  8. Ageing implementation and refurbishment development at the IEA-R1 nuclear research reactor: a 15 years experience

    Energy Technology Data Exchange (ETDEWEB)

    Cardenas, Jose Patricio N.; Ricci Filho, Walter; Carvalho, Marcos R. de; Berretta, Jose Roberto; Marra Neto, Adolfo, E-mail: ahiru@ipen.b, E-mail: wricci@ipen.b, E-mail: carvalho@ipen.b, E-mail: jrretta@ipen.b, E-mail: amneto@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    IPEN (Instituto de Pesquisas Energeticas e Nucleares) is a nuclear research center established into the Secretary of Science and Technology from the government of the state of Sao Paulo, and administered both technically and financially by Comissao Nacional de Energia Nuclear (CNEN), a federal government organization under the Ministry of Science and Technology. The institute is located inside the campus of the University of Sao Paulo, Sao Paulo city, Brazil. One of major nuclear facilities at IPEN is the IEA-R1 nuclear research reactor. It is the unique Brazilian research reactor with substantial power level suitable for application with research in physics, chemistry, biology and engineering, as well as radioisotope production for medical and other applications. Designed and built by Babcok-Wilcox, in accordance with technical specifications established by the Brazilian Nuclear Energy Commission, and financed by the US Atoms for Peace Program, it is a swimming pool type reactor, moderated and cooled by light water and uses graphite and beryllium as reflector elements. The first criticality was achieved on September 16, 1957 and the reactor is currently operating at 4.0 MW on a 64h per week cycle. Since 1996, an IEA-R1 reactor ageing study was established at the Research Reactor Center (CRPq) related with general deterioration of components belonging to some operational systems, as cooling towers from secondary cooling system, piping and pumps, sample irradiation devices, radiation monitoring system, fuel elements, rod drive mechanisms, nuclear and process instrumentation and safety operational system. Although basic structures are almost the same as the original design, several improvements and modifications in components, systems and structures had been made along reactor life. This work aims to show the development of the ageing program in the IEA-R1 reactor and the upgrading (modernization) that was carried out, concerning several equipment and system in the

  9. Real time monitoring system of the operation variables of the TRIGA IPR-R1 nuclear research reactor

    International Nuclear Information System (INIS)

    Ricardo, Carla Pereira; Mesquita, Amir Zacarias

    2007-01-01

    During the last two years all the operation parameters of the TRIGA IPR-R1 were monitored and real time indicated bu the data acquisition system developed for the reactor. All the information were stored on a rigid disk, at the collection system computer, leaving the information on the reactor performance and behaviour available for consultation in a chronological order. The data acquisition program has been updated and new reactor operation parameters were included for increasing the investigation and experiments possibilities. The register of reactor operation variables are important for the immediate or subsequent safety analyses for reporting the reactor operations to the external organizations. This data acquisition satisfy the IAEA recommendations. (author)

  10. Fuel element reactivity worth in different rings of the IPR-R1 TRIGA reactor

    Energy Technology Data Exchange (ETDEWEB)

    Gomes do Prado Souza, Rose Mary

    2008-10-29

    The thermal power of the IPR-R1 TRIGA Reactor will be upgraded from 100 kW to 250 kW. Starting core: loaded with 59 aluminum cladded fuel elements; 1.34 $ excess reactivity; and 100 kW power. It is planned to go 2.5 times the power licensed, i.e., 250 kW. This forces to enlarge the reactivity level. Nuclear reactors must have sufficient excess reactivity to compensate the negative reactivity feedback effects caused by: the fuel temperature, fuel burnup, fission poisoning production, and to allow full power operation for predetermined period of time. To provide information for the calculation of the new core arrangement, the reactivity worth of some fuel elements in the core were measured as well as the determination of the core reactivity increase in the substitution of the original fuels, cladded with aluminium, for new ones, cladded with stainless steel. The reactivity worth of fuel element was measured from the difference in critical position of the control rods, calibrated by the positive period method, before and after the fuel element was withdrawn from the core. The magnitude of reactivity increase was determined when withdrawing the original Al-clad fuel (a little burned up) and the graphite elements, and inserting a fresh Al-clad fuel element, one by one. Experimental results indicated that to obtain enough reactivity excess to increase the rector power the addition of 4 new fuel elements in the core would be sufficient: - Substitution of 4 Al-clad fuel elements in ring C for fresh stainless steel clad fuel elements; - increase the reactivity {approx_equal} 4 x 6.5 = 26 cents; - The removed 4 Al-clad F. E. (a little burned up) put in the core periphery, ring F, replacing graphite elements; - add < 4 x 39 156 cents (39 cents was measured with a fresh F.E.). Neutron source was changed from position F7 to F8. Control and Safety rods were moved from ring D to C in order to increase their reactivity worth. Regulating rod was kept at the same position, F16. Four

  11. Thermal power calibrations of the IPR-R1 TRIGA reactor by the calorimetric and the heat balance methods

    International Nuclear Information System (INIS)

    Mesquita, Amir Zacarias; Rezende, Hugo Cesar; Souza, Rose Mary Gomes do Prado

    2009-01-01

    Since the first nuclear reactor was built, a number of methodological variations have been evolved for the calibration of the reactor thermal power. Power monitoring of reactors is done by means of neutronic instruments, but its calibration is always done by thermal procedures. The purpose of this paper is to present the results of the thermal power calibration carried out on March 5th, 2009 in the IPR-R1 TRIGA reactor. It was used two procedures: the calorimetric and heat balance methods. The calorimetric procedure was done with the reactor operating at a constant power, with primary cooling system switched off. The rate of temperature rise of the water was recorded. The reactor power is calculate as a function of the temperature-rise rate and the system heat capacity constant. The heat balance procedure consists in the steady-state energy balance of the primary cooling loop of the reactor. For this balance, the inlet and outlet temperatures and the water flow in the primary cooling loop were measured. The heat transferred through the primary loop was added to the heat leakage from the reactor pool. The calorimetric method calibration presented a large uncertainty. The main source of error was the determination of the heat content of the system, due to a large uncertainty in the volume of the water in the system and a lack of homogenization of the water temperature. The heat balance calibration in the primary loop is the standard procedure for calibrating the power of the IPR-R1 TRIGA nuclear reactor. (author))

  12. Preliminary analysis of control rod accidents in the CRCN-R1 multipurpose reactor core of Recife in Brazil

    International Nuclear Information System (INIS)

    Souza dos Santos, Rubens; Rubens Maiorino, Jose

    1999-01-01

    The paper shows some results of the neutronic accident analyses arisen by uncontrolled control rod withdrawal, based on the Conceptual Project of the CRCN-R1 MultiPurpose Reactor of Recife. In that reactor, a project of the CNEN/Brazil, under the leadership of the IPEN/Sao Paulo, is verified the thermal hydraulic limits in the reactor core during transients that simulate startup and power operation accidents. It has utilized a computer program that solved the kinetic equations based on multigroup diffusion theory, in our case we have used 4 energy groups, Two-Dimensional X-Y in the space, and 6 groups of delayed neutrons. A simple model of feedback is admitted in the capture and scattering macroscopic cross sections, in the fuel regions, temperature and coolant densities dependents. Based on those models, the results demonstrated that the reactor exhibits good degree of safety. (author)

  13. Reactivity-worth estimates of the OSMOSE samples in the MINERVE reactor R1-UO2 configuration.

    Energy Technology Data Exchange (ETDEWEB)

    Klann, R. T.; Perret, G.; Nuclear Engineering Division

    2007-10-03

    An initial series of calculations of the reactivity-worth of the OSMOSE samples in the MINERVE reactor with the R1-UO2 core configuration were completed. The reactor model was generated using the REBUS code developed at Argonne National Laboratory. The calculations are based on the specifications for fabrication, so they are considered preliminary until sampling and analysis have been completed on the fabricated samples. The estimates indicate a range of reactivity effect from -22 pcm to +25 pcm compared to the natural U sample.

  14. Experiment of IEA-R1 reactor core cooling by air convection after pool water loss accident

    International Nuclear Information System (INIS)

    Torres, Walmir Maximo; Baptista Filho, Benedito Dias

    2000-01-01

    This paper presents a study of a Emergency Core Cooling to be applied to the IEA-R1 reactor. This system must have the characteristics of passive action, with water spraying over the core, and feeding by gravity from elevated reservoirs. In the evaluation, this system must demonstrate that when the reservoirs are emptied, the core cooling must assure to be fulfilled by air natural convection. This work presents the results of temperature distribution in a test section with plates electrically heated simulation the heat generation conditions on the most heated reactor element

  15. Doping of monocrystalline silicon with phosphorus by means of neutron irradiation at the IEA-R1 research reactor

    International Nuclear Information System (INIS)

    Carbonari, A.W.; Puget, M.A.C.

    1990-11-01

    The first neutron irradiation experiments with monocrystal silicon in the IEA-R1 research reactor of IPEN are related. The silicon is irradiated with phosphorus producing a N type semiconductor with a very small resistivity variation throughout the crystal volume. The neutrons induce nuclear reactions in Si-30 isotope and these atoms are then transformed in to phosphorous atoms. This process is known as Neutron Transmutation Doping. In order to irradiate the silicon crystals in the reactor, a specific device has been constructed, and it permits the irradiation of up to 2.5'' diameter monocrystals. (author)

  16. Measurement of thermal, epithermal and fast neutron flux in the IEA-R1 reactor by the foil activation method

    International Nuclear Information System (INIS)

    Koskinas, M.F.

    1979-01-01

    Experimental and theoretical details of the foil activation method applied to neutrons flux measurements at the IEA-R1 reactor are presented. The thermal - and epithermal - neutron flux were determined form activation measurements of gold, cobalt and manganese foils; and for the fast neutron flux determination, aluminum, iron and nickel foils were used. The measurements of the activity induced in the metal foils were performed using a Ge-Li gamma spectrometry system. In each energy range of the reactor neutron spectrum, the agreement among the experimental flux values obtained using the three kind of materials, indicates the consistency of the theoretical approach and of the nuclear parameters selected. (Author) [pt

  17. Design of a digital system for operational parameters simulation of IPR-R1 TRIGA nuclear research reactor

    International Nuclear Information System (INIS)

    Lage, Aldo M.F.; Mesquita, Amir Z.; Felippe, Adriano de A.M.

    2017-01-01

    The instrumentation of nuclear reactors is designed based on the reliability, redundancy and diversification of control systems. The monitoring of the parameters is of crucial importance with regard to the operational efficiency and safety of the installation. Since the first criticality of a nuclear reactor, achieved by Fermi et al. in 1942, there has been concern about the reliable monitoring of the parameters involved in the chain reaction. This paper presents the current stage of the system of simulation, which is under development at the CDTN, which intends to simulate the operation of the TRIGA IPR-R1 nuclear reactor, involving the evolution of neutron flux and reactor power related events. The system will be developed using LabVIEW® software, using the modern concept of virtual instruments (VIs) that are visualized in a video monitor. For the implementation of this model, computational tools and systems analysis are necessary, which help and facilitate the implementation of the simulator. In this article we will show some of these techniques and the initial design of the model to be implemented. The design of a computational system is of great importance, since it guides in the implementation stages and generates the documentation for later maintenance and updating of the computational system. It is noteworthy that the innovations developed in research reactors are normally used in power reactors. The relatively low costs enable research reactors to be an excellent laboratory for developing techniques for future reactors. (author)

  18. Design of a digital system for operational parameters simulation of IPR-R1 TRIGA nuclear research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lage, Aldo M.F.; Mesquita, Amir Z.; Felippe, Adriano de A.M., E-mail: aldo@cdtn.br, E-mail: amir@cdtn.br, E-mail: adrianoamfelippe@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN /CNEN-MG), Belo Horizonte, MG (Brazil); Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2017-11-01

    The instrumentation of nuclear reactors is designed based on the reliability, redundancy and diversification of control systems. The monitoring of the parameters is of crucial importance with regard to the operational efficiency and safety of the installation. Since the first criticality of a nuclear reactor, achieved by Fermi et al. in 1942, there has been concern about the reliable monitoring of the parameters involved in the chain reaction. This paper presents the current stage of the system of simulation, which is under development at the CDTN, which intends to simulate the operation of the TRIGA IPR-R1 nuclear reactor, involving the evolution of neutron flux and reactor power related events. The system will be developed using LabVIEW® software, using the modern concept of virtual instruments (VIs) that are visualized in a video monitor. For the implementation of this model, computational tools and systems analysis are necessary, which help and facilitate the implementation of the simulator. In this article we will show some of these techniques and the initial design of the model to be implemented. The design of a computational system is of great importance, since it guides in the implementation stages and generates the documentation for later maintenance and updating of the computational system. It is noteworthy that the innovations developed in research reactors are normally used in power reactors. The relatively low costs enable research reactors to be an excellent laboratory for developing techniques for future reactors. (author)

  19. Application of safety checklist to the analysis of the IEA-R1 reactor water retreatment system

    International Nuclear Information System (INIS)

    Sauer, Maria Eugenia Lago Jacques; Sara Neto, Antonio Jorge; Lima, Toni Carlos Caboclo de; Ribeiro, Maria Alice Morato

    2005-01-01

    In 1999, the management of the IEA-R1 Research Reactor (pool type - 5 MWth), located at IPEN/CNEN-SP, started the evaluation of the Reactor Pool Water Retreatment System to identify operational aspects, which could compromise the operators safety. The purpose was to identify and propose enhancements to the system which would be installed to substitute for the existing one. This process was conducted through a qualitative study of the system in operation. This study was carried out by a team composed of specialists in reactor operation, systems maintenance and radiological protection, and one safety analyst. The study consisted, basically, in local inspections to verify the physical and operational conditions of each equipment / component as well as aspects related to maintenance activities of the system. The process control and the operator procedures associated with the retreatment of the reactor pool water were also reviewed. The methodology adopted to develop the study was based in process hazard analysis technique named Safety Checklist. This paper presents a summary of this study and the main results obtained. Some operational and safety problems identified, the prevention and/or correction means to avoid them, and the recommendations and suggestions that have been implemented to the new design of the IEA-R1 Reactor Water Retreatment System, whose installation was concluded in 2003, are also presented. (author)

  20. Measurement and calculation of spatial and energetic neutron flux in the IEA-R1 reactor core

    International Nuclear Information System (INIS)

    Bittelli, U.D.

    1988-01-01

    This work presents spatial and energetic flux distribution measured in the IEA-R1 reactor core. The thermal neutron flux was measured by gold activation foils (bare and covered with cadmium) in the fuel element number 108 (reaction: 197 Au(n,γ) 198 Au) at 451W overall reactor power. The fast neutron flux was measured by indium activation foils (reaction: 115 In(n,n') 115m In) in the fuel elements number 94 at 4510W overall reactor power. The neutron energy spectrum was adjusted by SAND II code with the data produced by the irradiation of seven activation detectors in the fuel element number 94 at 4510 W overall reactor power. The following reactions were used: 58 Fe(n,γ) 59 Fe, 232 Th(n,γ) 233 Th, 197 Au(n,γ) 198 Au, 59 Co(n,γ) 60 Co, 54 Fe(n,p) 54 Mn, 24 Mg(n,p) 24 Na, 47 Ti(n,p) 47 Sc, 48 Ti(n,p) 48 Sc and 115 In(n,n') 115m In. The experimental results compared to those obtained by CITATION (spatial distribution flux) and HAMMER (energetic distribution flux) code, showed good agreement. The results presented in this work are a good contribution for a better knowledge of spatial and energetic neutron flux distribution in the IEA-R1 reactor core, besides that the experimental procedure is easily applicable to another situations. (autor) [pt

  1. Fission track dating method: I. Study of neutron flux uniformity in some irradiation positions of IEA-R1 reactor

    International Nuclear Information System (INIS)

    Osorio, A.M.; Hadler, J.C.; Iunes, P.J.; Paulo, S.R. de

    1993-06-01

    In order to use the fission track dating method the flux gradient was verified within the sample holder, in some irradiation positions of the IEA-R1 reactor at IPEN/CNEN, Sao Paulo. The fission track dating method considers only the thermal neutron fission tracks, to subtract the other contributions sample irradiations with a cadmium cover was performed. The neutron flux cadmium influence was studied. (author)

  2. Studies review and exploration purpose of neutron radiography technique in the TRIGA IPR-R1 reactor at CDTN, Brazil

    International Nuclear Information System (INIS)

    Costa, Antonella Lombardi; Amorim, Valter Alves de; Stasiulevicius, Roberto; Rocha, Zildete

    2002-01-01

    Neutron Radiography - NR - consists of obtaining on a sensitive plate, the image produced by neutron flux after crossing an object. Through NR is possible to inspect plastics and explosives materials and organic composition. Is difficult to analyze these materials by the radiography technique. The neutron beam extractor was installed, in the TRIGA IPR-R1 reactor at the CDTN. This work presents preliminaries results of the NR researches in the past at CDTN, which are being retaken. (author)

  3. Measurement of thermal, epithermal and fast neutrons fluxes by the activation foil method at IEA-R1 reactor

    International Nuclear Information System (INIS)

    Dias, M.S.; Koskinas, M.F.; Berretta, J.R.; Fratin, L.; Botelho, S.

    1990-01-01

    The thermal, epithermal and fast neutron fluxes have been determined experimentally by the activation foil method at position GI, located near the IEA-R1 reactor core. The reactions used were 197 Au (n,gamma) 198 Au, for thermal and epithermal neutrons and 27 Na (n,alpha) 24 Na, for fast neutrons. The activities were measured by the 4π(PC)β-γ coincidence method. (author)

  4. Considerations about decommissioning of the IEA-R1 research reactor and the future of its installations after shutdown

    International Nuclear Information System (INIS)

    Frajndlich, Roberto

    2014-01-01

    The IEA-R1 Nuclear Research Reactor, in operation since 1957, in the Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), is one of the oldest research reactors in the world. However at some point in time in the future, as example of the other reactors, it will be shutdown definitively. Before that time actually arrives, the operational organization needs to plan the future of its installations and define the final destination of equipment and radioactive as well as non-radioactive material contained inside the installations. These and other questions should be addressed in the so called Preliminary decommissioning plan of the installation, which is the subject of this work. The work initially presents an over view about the theme and defines the general and specific objectives describing, in succession, the directions that the operating organization should consider for the formulation of a decommissioning plan. The present structure of the Brazilian nuclear sector emphasizing principally the norms utilized in the management of radioactive waste is also presented. A description of principle equipment of the IEA-R1 reactor which constitutes its inventory of radioactive and non-radioactive material is given. The work emphasizes the experience of the reactor technicians, acquired during several reforms and modifications of the reactor installations realized during its useful life time. This experience may be of great help for the decommissioning in the future. An experiment using the high resolution gamma spectrometric method and computer calculation using Monte Carlo theory were performed with the objective of obtaining an estimate of the radioactive waste produced from dismantling of the reactor pool walls. The cost of reactor decommissioning for different choices of strategies was determined using the CERREX code. Finally, a discussion about different strategies is presented. On the basis of these discussions it is concluded that the most advantageous

  5. Sipping test update device for fuel elements cladding inspections in IPR-r1 TRIGA reactor

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, R.R.; Mesquita, A.Z.; Andrade, E.P.D.; Gual, Maritza R., E-mail: rrr@cdtn.br, E-mail: amir@cdtn.br, E-mail: edson@cdtn.br, E-mail: maritzargual@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-07-01

    It is in progress at the Centro de Desenvolvimento da Tecnologia Nuclear - CDTN (Nuclear Technology Development Center), a research project that aims to investigate possible leaks in the fuel elements of the TRIGA reactor, located in this research center. This paper presents the final form of sipping test device for TRIGA reactor, and results of the first experiments setup. Mechanical support strength tests were made by knotting device on the crane, charged with water from the conventional water supply, and tests outside the reactor pool with the use of new non-irradiated fuel elements encapsulated in stainless steel, and available safe stored in this unit. It is expected that tests with graphite elements from reactor pool are done soon after and also the test experiment with the first fuel elements in service positioned in the B ring (central ring) of the reactor core in the coming months. (author)

  6. Sipping test update device for fuel elements cladding inspections in IPR-r1 TRIGA reactor

    International Nuclear Information System (INIS)

    Rodrigues, R.R.; Mesquita, A.Z.; Andrade, E.P.D.; Gual, Maritza R.

    2015-01-01

    It is in progress at the Centro de Desenvolvimento da Tecnologia Nuclear - CDTN (Nuclear Technology Development Center), a research project that aims to investigate possible leaks in the fuel elements of the TRIGA reactor, located in this research center. This paper presents the final form of sipping test device for TRIGA reactor, and results of the first experiments setup. Mechanical support strength tests were made by knotting device on the crane, charged with water from the conventional water supply, and tests outside the reactor pool with the use of new non-irradiated fuel elements encapsulated in stainless steel, and available safe stored in this unit. It is expected that tests with graphite elements from reactor pool are done soon after and also the test experiment with the first fuel elements in service positioned in the B ring (central ring) of the reactor core in the coming months. (author)

  7. Analysis of the IEA-R1 reactor start-up procedures - an application of the HazOp method

    International Nuclear Information System (INIS)

    Sauer, Maria Eugenia Lago Jacques

    2000-01-01

    An analysis of technological catastrophic events that took place in this century shows that human failure and vulnerability of risk management programs are the main causes for the occurrence of accidents. As an example, plants and complex systems where the interface man-machine is close, the frequency of failures tends to be higher. Thus, a comprehensive knowledge of how a specific process can be potentially hazardous is a sine qua non condition to the operators training, as well as to define and implement more efficient plans for loss prevention and risk management. A study of the IEA-R1 research reactor start-up procedures was carried out, based upon the methodology Hazard and Operability Study (HazOp). The analytical and qualitative multidisciplinary HazOp approach provided means to a comprehensive review of the reactor start-up procedures, contributing to improve the understanding of the potential hazards associated to deviations on performing this routine. The present work includes a historical summary and a detailed description of the HazOp technique, as well as case studies in the process industries and the use of expert systems in the application of the method. An analysis of 53 activities of the IEA-R1 reactor start-up procedures was made, resulting in 25 recommendations of changes covering aspects of the project, operation and safety of the reactor. Eleven recommendations have been implemented. (author)

  8. Upgrading the electrical system of the IEA-R1 reactor to avoid triggering event of accidents

    International Nuclear Information System (INIS)

    Mello, Jose Roberto de; Madi Filho, Tufic

    2015-01-01

    The IEA-R1 research reactor at the Institute of Energy and Nuclear Research (IPEN) is a research reactor open pool type, built and designed by the American firm 'Babcox and Wilcox', having as coolant and moderator demineralized light water and Beryllium and graphite, as reflectors. The power supply system is designed to meet the electricity demand required by the loads of the reactor (Security systems and systems not related to security) in different situations the plant can meet, such as during startup, normal operation at power, shutdown, maintenance, exchange of fuel elements and accident situations. Studies have been done on possible accident initiating events and deterministic techniques were applied to assess the consequences of such incidents. Thus, the methods used to identify and select the accident initiating events, the methods of analysis of accidents, including sequence of events, transient analysis and radiological consequences, have been described. Finally, acceptance criteria of radiological doses are described. Only a brief summary of the item concerning loss of electrical power will be presented. The loss of normal electrical power at the IEA-R1 reactor is very common. In the case of Electric External Power Loss, at the IEA-R1 reactor building, there may be different sequences of events, as described below. When the supply of external energy in the IEA-R1 facility fails, the Electrical Distribution Vital System, consisting of 4 (four) generators type 'UPS', starts operation, immediately and it will continue supplying power to the reactor control table, core cooling system and other security systems. To contribute to security, in the electric power failure, starts to operate the Emergency Cooling System (SRE). SRE has the function of removing residual heat from the core to prevent the melting of fuel elements in the event of loss of refrigerant to the core. Adding to the generators with batteries group system, new auxiliary

  9. Thermal neutron flux measurements in the rotary specimen rack of the IPR-R1 TRIGA reactor

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Rose Mary G. do Prado; Rodrigues, Rogério R.; Souza, Luiz Claudio A., E-mail: souzarm@cdtn.br, E-mail: rrr@cdtn.br, E-mail: lcas@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-07-01

    The thermal neutron flux in the rotary specimen rack of the IPR-R1 TRIGA reactor at the Nuclear Technology Development Center (CDTN), Belo Horizonte, Brazil, has been measured by the neutron activation method, using bare and cadmium covered gold foils. Those foils were irradiated in the rotary specimen rack with the reactor at 100 kW. The reactor core configuration has 63 fuel elements, composed of 59 original aluminum-clad elements and 4 stainless steel-clad fuel elements. The gamma activities of the foils were measured using Ge spectrometer. The perturbations of the thermal neutron flux caused by the introduction of an absorbing foil into the medium were considered in order to obtain accurate determination of the flux. The thermal neutron flux obtained was 7.4 x 10{sup 11} n.cm{sup -2}.s{sup -1}. (author)

  10. Application of nondestructive methods for qualification of high density fuels in the IEA-R1 reactor

    International Nuclear Information System (INIS)

    Silva, Jose E.R.; Silva, Antonio T.; Domingos, Douglas B.; Terremoto, Luis A.A.

    2011-01-01

    IPEN/CNEN-SP manufactures fuels to be used in its research reactor - the IEA-R1. To qualify those fuels, it is necessary to check if they have a good performance under irradiation. As Brazil still does not have nuclear research reactors with high neutron fluxes, or suitable hot cells for carrying out post-irradiation examination of nuclear fuels, IPEN/CNEN-SP has conducted a fuel qualification program based on the use of uranium compounds (U 3 O 8 and U 3 Si 2 dispersed in Al matrix) internationally tested and qualified to be used in research reactors, and has attained experience in the technological development stages for the manufacturing of fuel plates, irradiation and non-destructive post-irradiation testing. Fuel elements containing low volume fractions of fuel in the dispersion were manufactured and irradiated successfully directly in the core of the IEA-R1. However, there are plans at IPEN/CNEN-SP to increase the uranium density of the fuels. Ten fuel miniplates (five containing U 3 O 8 -Al and five containing U 3 Si 2 -Al), with densities of 3.2 gU/cm 3 and 4.8 gU/cm 3 respectively, are being irradiated inside an irradiation device placed in a peripheral position of the IEA-R1 core. Non-destructive methods will be used to evaluate irradiation performance of the fuel miniplates after successive cycles of irradiation, by means: monitoring the reactor parameters during operation; periodic underwater visual inspection of fuel miniplates, eventual sipping test for fuel miniplates suspected of leakage and underwater measuring of the miniplate thickness for assessment of the fuel miniplate swelling. (author)

  11. Application of nondestructive methods for qualification of high density fuels in the IEA-R1 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Jose E.R.; Silva, Antonio T.; Domingos, Douglas B.; Terremoto, Luis A.A., E-mail: jersilva@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    IPEN/CNEN-SP manufactures fuels to be used in its research reactor - the IEA-R1. To qualify those fuels, it is necessary to check if they have a good performance under irradiation. As Brazil still does not have nuclear research reactors with high neutron fluxes, or suitable hot cells for carrying out post-irradiation examination of nuclear fuels, IPEN/CNEN-SP has conducted a fuel qualification program based on the use of uranium compounds (U{sub 3}O{sub 8} and U{sub 3}Si{sub 2} dispersed in Al matrix) internationally tested and qualified to be used in research reactors, and has attained experience in the technological development stages for the manufacturing of fuel plates, irradiation and non-destructive post-irradiation testing. Fuel elements containing low volume fractions of fuel in the dispersion were manufactured and irradiated successfully directly in the core of the IEA-R1. However, there are plans at IPEN/CNEN-SP to increase the uranium density of the fuels. Ten fuel miniplates (five containing U{sub 3}O{sub 8}-Al and five containing U{sub 3}Si{sub 2}-Al), with densities of 3.2 gU/cm{sup 3} and 4.8 gU/cm{sup 3} respectively, are being irradiated inside an irradiation device placed in a peripheral position of the IEA-R1 core. Non-destructive methods will be used to evaluate irradiation performance of the fuel miniplates after successive cycles of irradiation, by means: monitoring the reactor parameters during operation; periodic underwater visual inspection of fuel miniplates, eventual sipping test for fuel miniplates suspected of leakage and underwater measuring of the miniplate thickness for assessment of the fuel miniplate swelling. (author)

  12. The past and the future in the forty years of the IPR-R1 TRIGA MARK I reactor operation

    International Nuclear Information System (INIS)

    Maretti Junior, Fausto

    2008-01-01

    Full text: The nuclear IPR-R1 TRIGA Mark I Reactor operating in the Nuclear Technology Development Center, originally Institute for Radioactive Research in Minas Gerais, Brazil, was dedicated in November 11, 1960. Initially operating for the production of radioisotopes for different uses, it started later to be used in large scale for neutron activation analysis and training of operators for nuclear power plants. Many improvements have been made throughout these years to provide a better performance in its operation and safety conditions. A new cooling system to operate until 300 kW, a new control rod mechanism, an aluminum tank for the reactor pool, an optimization in the pneumatic system, a new reactor control console and a general remodeling of the reactor laboratory were some of the improvements added. During these years a lot of irradiations, analysis , MSc and PhD thesis, training courses and isotopes production take place at the reactor. This paper describes the improvements made, the results obtained during the past 40 years, type of works realized, isotopes produced, the neutron activation analysis and the precautions taken to ensure future safe operation of the reactor to give operators better conditions of safe work. (authors)

  13. Dose measurements in controlled area and laboratory of TRIGA IPR-R1 reactor

    International Nuclear Information System (INIS)

    Maretti Junior, Fausto; Alvarenga, Frederico Ladeia

    2005-01-01

    The workers doses in exposure areas to the radiation are so important for a Radioprotection Quality Program, as well as to guarantee the workers safety. For that it is necessary to raise the doses in the radiation areas, to obtain the accumulated dose in certain procedures for detailed studies. Several risings were accomplished to obtain the radiation levels in the areas where the workers are exposed due the operation of a research nuclear reactor and in the radioisotopes manipulation laboratories of a nuclear institute. The radiation levels and doses can be observed through graphs in the dependences of the Controlled Area 1 (AC-1) and the Reactor Laboratory. Those limits are in according of the CNEN-NE-3.01 work limits rules. The conclusion of the work allowed to demonstrate that the Laboratory of the Reactor and AC-1, have booth an effective radiological program with efficient operational practices that contributes with low doses to the workers. (author)

  14. Dose measurements in controlled area of TRIGA IPR-R1 reactor

    International Nuclear Information System (INIS)

    Alvarenga, F.L.; Junior, F.M.

    2005-01-01

    The workers doses in exposure areas to the radiation are so important for a Radioprotection Quality Program, as well as to guarantee the workers safety. For that it is necessary to raise the doses in the radiation areas, to obtain the accumulated dose in certain procedures for detailed studies. Several risings were accomplished to obtain the radiation levels in the areas where the workers are exposed due the operation of a research nuclear reactor and in the radioisotopes manipulation laboratories of a nuclear institute. The radiation levels and doses can be observed through graphs in the dependences of the Controlled Area 1 (AC-1) and the Reactor Laboratory. Those limits are in according of the CNEN-NE-3.01 work limits rules. The conclusion of the work allowed to demonstrate that the Laboratory of the Reactor and AC-1, have booth an effective radiological program with efficient operational practices that contributes with low doses to the workers

  15. A CFD model for the IEA-R1 reactor neat exchanger inlet nozzle flow

    International Nuclear Information System (INIS)

    Andrade, Delvonei A.; Angelo, Gabriel; Gainer, Gerson; Angelo, Edvaldo; Umbehaun, Pedro E.; Torres, Walmir M.; Sabundjian, Gaiane; Macedo, Luiz A.; Belchior Junior, Antonio; Conti, Thadeu N.; Watanabe, Bruno C.; Sakai, Caio C.

    2011-01-01

    A previous preliminary model of the IEA-R1 heat exchanger inlet nozzle flow was developed and published in the International Nuclear Atlantic Conference-INAC-2009. A new model was created based on the preliminary one. It was improved concerning the actual heat exchanger tube bundle geometry. This became a very special issue. Difficulties with the size of the numerical mesh came out pointing to our computational system limits. New CFD calculations with this improved model were performed using ANSYS-CFX. In this paper, we present this model and discuss the results. (author)

  16. A CFD model for the IEA-R1 reactor neat exchanger inlet nozzle flow

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Delvonei A.; Angelo, Gabriel; Gainer, Gerson; Angelo, Edvaldo; Umbehaun, Pedro E.; Torres, Walmir M.; Sabundjian, Gaiane; Macedo, Luiz A.; Belchior Junior, Antonio; Conti, Thadeu N.; Watanabe, Bruno C.; Sakai, Caio C., E-mail: delvonei@ipen.b, E-mail: gfainer@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    A previous preliminary model of the IEA-R1 heat exchanger inlet nozzle flow was developed and published in the International Nuclear Atlantic Conference-INAC-2009. A new model was created based on the preliminary one. It was improved concerning the actual heat exchanger tube bundle geometry. This became a very special issue. Difficulties with the size of the numerical mesh came out pointing to our computational system limits. New CFD calculations with this improved model were performed using ANSYS-CFX. In this paper, we present this model and discuss the results. (author)

  17. Radiation levels in the poll surface of IEA-R1 reactor

    International Nuclear Information System (INIS)

    Pasqualetto, H.

    1978-01-01

    A theoretical model for the calculation of the radioactivity level in the pool surface of the research reactor IEA-RI (INSTITUTO DE ENERGIA ATOMICA, BRAZIL) is developed. The radioactivity is caused by radionuclides (Mainly 24 Na and 27 Mg) produced by nuclear reactions of neutrons with: a) oxygen of the water b); gaseous elements dissolved in water (Ar,N); c) structural materials of the fuel can. Considerations about expected radiation level after eventual increase of reactor power from 2 MW to 10 MW are also presented [pt

  18. Device for neutron flux monitoring in IEA-R1 reactor using rhodium self powered neutron detector; Dispositivo de mapeamento de fluxo de neutron atraves do SPN/Rodio no IEA-R1

    Energy Technology Data Exchange (ETDEWEB)

    Ricci Filho, Walter; Fernando, Alberto de Jesus; Jerez, Rogerio; Tondin, Julio B.M.; Pasqualetto, Hertz [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    2000-07-01

    The IEA-R1 reactor has undergone a modernization tio increase its operating power to 5 MW, in order to allow a more efficient production of radioisotopes. The objective of this work is to provide the reactor with flux monitoring device using a rhodium self powered neutron detector. Self powered detectors are rugged miniature devices with are increasingly being used for fixed in core reactor monitoring both for safety purposes and flux mapping. The work presents the results obtained with Rhodium-SPND in several irradiation position inside the reactor core. (author)

  19. Data acquisition and signal processing system for IPR R1 TRIGA-Mark I nuclear research reactor of CDTN

    International Nuclear Information System (INIS)

    Mesquita, A.Z.; Maretti, F. Jr.; Rezende, H.C.; Tambourgi, E.B.

    2004-01-01

    The TRIGA IPR-R1 Nuclear Research Reactor, located at the Nuclear Technology Development Center (CDTN/CNEN) in Belo Horizonte, Brazil, is being operated since 44 years ago. The main operational parameters were monitored by analog recorders and counters located in the reactor control console. The reactor operators registered the most important operational parameters and data in the reactor logbook. This process is quite useful, but it can involve some human errors. It is also impossible for the operators to take notes of all variables involving the process mainly during fast power transients in some operations. A PC-based data acquisition was developed for the reactor that allows online monitoring, through graphic interfaces, and shows operational parameters evolution to the operators. Some parameters that were not measured, like the power and the coolant flow rate at the primary loop, are monitored now in the computer video monitor. The developed system allows measuring out all parameters in a frequency up to 1 kHz. These data is also recorded in text files available for consults and analysis. (author)

  20. Spatial distribution of the neutron flux in the IEA-R1 reactor core obtained by means of foil activation

    International Nuclear Information System (INIS)

    Mestnik Filho, J.

    1979-01-01

    A three-dimensional distribution of the neutron flux in IEA-R1 reactor, obtained by activating gold foils, is presented. The foils of diameter 8mm and thickness 0,013mm were mounted on lucite plates and located between the fuel element plates. Foil activities were measured using a 3x3 inches Nal(Tl) scintilation detector calibrated against a 4πβγ coincidence detector. Foil positions were chosen to minimize the errors of measurement; the overall estimated error on the measured flux is 5%. (Author) [pt

  1. Hazard and operability study (Haz Op) of the 2 MW IEA-R1 reactor startup procedures

    International Nuclear Information System (INIS)

    Sauer, Maria E.L.J.; Correa, Francisco; Sara Neto, Antonio J.; Costa, Carlos A.R. da; Santos, Cilas C. dos; Cardenas, Jose P.N.; Berretta, Jose R.; Neves Conti, Thadeu das

    1997-01-01

    This work presents the Hazard and Operability Study (Haz Op) applied to startup procedures of the 2 MW IEA-R1 research reactor, at IPEN/CNEN-S P. The Haz Op was developed by reviewing the procedures of the installation startup, in order to identify hazards and/or operational problems caused by deviations in the execution of these routines. This paper summarizes this study. describing some potential problems of relevant importance to safety as well as preventives and/or correctives measures to avoid their occurrence. Besides, an benefits evaluation and the technique limitations is made. (author). 5 refs., 1 tab

  2. International benchmark study of advanced thermal hydraulic safety analysis codes against measurements on IEA-R1 research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Hainoun, A., E-mail: pscientific2@aec.org.sy [Atomic Energy Commission of Syria (AECS), Nuclear Engineering Department, P.O. Box 6091, Damascus (Syrian Arab Republic); Doval, A. [Nuclear Engineering Department, Av. Cmdt. Luis Piedrabuena 4950, C.P. 8400 S.C de Bariloche, Rio Negro (Argentina); Umbehaun, P. [Centro de Engenharia Nuclear – CEN, IPEN-CNEN/SP, Av. Lineu Prestes 2242-Cidade Universitaria, CEP-05508-000 São Paulo, SP (Brazil); Chatzidakis, S. [School of Nuclear Engineering, Purdue University, West Lafayette, IN 47907 (United States); Ghazi, N. [Atomic Energy Commission of Syria (AECS), Nuclear Engineering Department, P.O. Box 6091, Damascus (Syrian Arab Republic); Park, S. [Research Reactor Design and Engineering Division, Basic Science Project Operation Dept., Korea Atomic Energy Research Institute (Korea, Republic of); Mladin, M. [Institute for Nuclear Research, Campului Street No. 1, P.O. Box 78, 115400 Mioveni, Arges (Romania); Shokr, A. [Division of Nuclear Installation Safety, Research Reactor Safety Section, International Atomic Energy Agency, A-1400 Vienna (Austria)

    2014-12-15

    Highlights: • A set of advanced system thermal hydraulic codes are benchmarked against IFA of IEA-R1. • Comparative safety analysis of IEA-R1 reactor during LOFA by 7 working teams. • This work covers both experimental and calculation effort and presents new out findings on TH of RR that have not been reported before. • LOFA results discrepancies from 7% to 20% for coolant and peak clad temperatures are predicted conservatively. - Abstract: In the framework of the IAEA Coordination Research Project on “Innovative methods in research reactor analysis: Benchmark against experimental data on neutronics and thermal hydraulic computational methods and tools for operation and safety analysis of research reactors” the Brazilian research reactor IEA-R1 has been selected as reference facility to perform benchmark calculations for a set of thermal hydraulic codes being widely used by international teams in the field of research reactor (RR) deterministic safety analysis. The goal of the conducted benchmark is to demonstrate the application of innovative reactor analysis tools in the research reactor community, validation of the applied codes and application of the validated codes to perform comprehensive safety analysis of RR. The IEA-R1 is equipped with an Instrumented Fuel Assembly (IFA) which provided measurements for normal operation and loss of flow transient. The measurements comprised coolant and cladding temperatures, reactor power and flow rate. Temperatures are measured at three different radial and axial positions of IFA summing up to 12 measuring points in addition to the coolant inlet and outlet temperatures. The considered benchmark deals with the loss of reactor flow and the subsequent flow reversal from downward forced to upward natural circulation and presents therefore relevant phenomena for the RR safety analysis. The benchmark calculations were performed independently by the participating teams using different thermal hydraulic and safety

  3. Development of a computational program to planning and control of the IEA-R1 reactor maintenance

    International Nuclear Information System (INIS)

    Martins, Mauro Onofre; Madi Filho, Tufic

    2013-01-01

    Maintenance is an essential activity in nuclear reactors. The components of safety systems of an industrial plant should have a low probability of failure, especially if there is a high risk of accidents that may cause environmental damage. In nuclear facilities, the presence of security systems is a technical specification and a requirement for their license and operation. In order to manage the entire information flow from the maintenance of the IEA-R1, a computational program (software) was developed, which not only plans and control all the maintenance, but also updates the documents and records to safeguard the quality, ensuring the safe operation of the reactor. The software has access levels and provides detailed reports of all maintenance planned and implemented, together with an individual history of the equipment during its lifetime in the facility. This work presents all the stages of the software development, description, compatibility, application, advantages and results obtained experimentally. (author)

  4. The implementation and evaluation of physical protection system of the IEA-R1 reactor

    International Nuclear Information System (INIS)

    Vaz, Antonio Carlos Alves

    2016-01-01

    The September 11, 2001 terrorist attacks in New York, the accident at the Fukushima nuclear power plant on March 2011 and the recent attacks in Paris on November 2015 are examples of events that justify the efforts of the International Agency of Energy Atomic - IAEA to improve security at nuclear facility. The Brazilian government has been collaborating with this project and investing resources to improve the Physical Protection System - PPS of the nuclear research reactor system, technically is associated with the elements of detection, delay and response. The PPS is an integrated system of people, equipment and procedures used to protect nuclear facilities and radioactive sources against threat, theft or sabotage. The PPS works to avoid, to mitigate or to minimize the consequences caused by these actions. This study evaluates the PPS of the reactor, identifying the vulnerabilities and suggesting ways to improve the system effectiveness. The analyses were based on the methodology developed by Sandia National Laboratories´ security experts in Albuquerque - USA, allowing the system evaluation through hypothetical and probabilistic analyzes; identifying threats, determining the targets and analyzing the possible adversaries paths. From the methodology adopted was obtained the value around 40% for PE indicator, which shows the need to improve the system to minimizing the vulnerabilities. (author)

  5. Characterization of the water filters cartridges from the iea-r1 reactor using the Monte Carlo method

    International Nuclear Information System (INIS)

    Costa, Priscila; Potiens Junior, Ademar J.

    2015-01-01

    Filter cartridges are part of the primary water treatment system of the IEA-R1 Research Reactor and, when saturated, they are replaced and become radioactive waste. The IEA-R1 is located at the Nuclear and Energy Research Institute (IPEN), in Sao Paulo, Brazil. The primary characterization is the main step of the radioactive waste management in which the physical, chemical and radiological properties are determined. It is a very important step because the information obtained in this moment enables the choice of the appropriate management process and the definition of final disposal options. In this paper, it is presented a non-destructive method for primary characterization, using the Monte Carlo method associated with the gamma spectrometry. Gamma spectrometry allows the identification of radionuclides and their activity values. The detection efficiency is an important parameter, which is related to the photon energy, detector geometry and the matrix of the sample to be analyzed. Due to the difficult to obtain a standard source with the same geometry of the filter cartridge, another technique is necessary to calibrate the detector. The technique described in this paper uses the Monte Carlo method for primary characterization of the IEA-R1 filter cartridges. (author)

  6. The evolution of doses in the IEA-R1 reactor environment and tendencies based on the current results

    International Nuclear Information System (INIS)

    Toyoda, Eduardo Yoshio

    2016-01-01

    The IPEN / CNEN-SP have a Nuclear Research Reactor-NRR named IEA-R1, in operation from 1957. It is an open swimming pool reactor using light water as shielding, moderator and as cooling, the volume of this pool is 273m 3 .Until 1995 the reactor operated daily at a power of 2,0 MW. From June of that year, after a few safety modifications the reactor began operating in continuous way from Monday to Wednesday without shutdown totalizing 64 hours per week and the power was increased to 4,5MW also. Because of these changes, continuous operation and increased power, workers' doses would tend to increase. In the past several studies were conducted seeking ways to reduce the workers' doses. A study was made on the possibility to introduce a shielding at the top of the reactor core with a hot water layer. Studies have shown that a major limitation for operating a reactor at high power comes from the gamma radiation emitted by the sodium-24. Other elements such as magnesium-27, aluminum-28, Argon-51, contribute considerably to the water activity of the pool. The introduction of a hot water layer on the swimming pool would form a layer of surface, stable and free of radioactive elements with a 1.5m to 2m thickness creates a shielding to radiation from radioactive elements dissolved in water. Optimization studies proved that the installation of the hot layer was not necessary for the regime and the current power reactor operation, because other procedures adopted were more effective. From this decision the Radiological Protection Reactor Team, set up a dose assessment program to ensure them remained in low values based on principles established in national and international standards. The purpose of this paper is to analyze the individual doses of OEI (Occupationally Exposed Individual), which will be checked increasing doses resulting from recent changes in reactor operation regime and suggested viable safety and protection options, in the first instance to reducing

  7. OSMOSE program : statistical review of oscillation measurements in the MINERVE reactor R1-UO2 configuration.

    Energy Technology Data Exchange (ETDEWEB)

    Stoven, G.; Klann, R.; Zhong, Z.; Nuclear Engineering Division

    2007-08-28

    The OSMOSE program is a collaboration on reactor physics experiments between the United States Department of Energy and the France Commissariat Energie Atomique. At the working level, it is a collaborative effort between the Argonne National Laboratory and the CEA Cadarache Research Center. The objective of this program is to measure very accurate integral reaction rates in representative spectra for the actinides important to future nuclear system designs, and to provide the experimental data for improving the basic nuclear data files. The main outcome of the OSMOSE measurement program will be an experimental database of reactivity-worth measurements in different neutron spectra for the heavy nuclides. This database can then be used as a benchmark to verify and validate reactor analysis codes. The OSMOSE program (Oscillation in Minerve of isotopes in Eupraxic Spectra) aims at improving neutronic predictions of advanced nuclear fuels through oscillation measurements in the MINERVE facility on samples containing the following separated actinides: {sup 232}Th, {sup 233}U, {sup 234}U, {sup 235}U, {sup 236}U, {sup 238}U, {sup 237}Np, {sup 238}Pu, {sup 239}Pu, {sup 240}Pu, {sup 241}Pu, {sup 242}Pu, {sup 241}Am, {sup 243}Am, {sup 244}Cm, and {sup 245}Cm. The first part of this report provides an overview of the experimental protocol and the typical processing of a series of experimental results which is currently performed at CEA-Cadarache. In the second part of the report, improvements to this technique are presented, as well as the program that was created to process oscillation measurement results from the MINERVE facility in the future.

  8. Characterization of filters cartridges from the water polishing system of IEA-R1 reactor: radiometric methods

    International Nuclear Information System (INIS)

    Tessaro, Ana Paula G.; Vicente, Roberto

    2015-01-01

    The acceptance of radioactive waste in a repository depends primarily on knowledge of the radioisotopic inventory of the material, according to regulations established by regulatory agencies. The primary characterization is also a fundamental action to determine further steps in the management of the radioactive wastes. The aim of this work is to report the development of non-destructive methods for primary characterization of filters cartridges discarded as radioactive waste. The filters cartridges are used in the water polishing system of the IEA-R1 reactor retaining the particles in suspension in the reactor cooling water. The IEA-R1 is a pool type reactor with a thermal power of 5 MW, moderated and cooled with light water. It is located in the Energy and Nuclear Research Institute (IPEN-CNEN), in São Paulo, Brazil. The cartridge filters become radioactive waste when they are saturated and do not meet the required flow for the proper operation of the water polishing system. The activities of gamma emitters present in the filters are determined using gamma spectrometry, dose rate measurements and the Point Kernel Method to correlate results from both measurements. For the primary characterization, one alternative method is the radiochemical analysis of slices taken from each filter, what presents the disadvantage of higher exposures personnel and contamination risks. Another alternative method is the calibration of the measurement geometry of a gamma spectrometer, which requires the production of a standard filter. Both methods are necessary but can not be used in operational routine of radioactive waste management owing to cost and complexity. The method described can be used to determine routinely the radioactive inventory of these filters and other radioactive wastes, avoiding the necessity of destructive radiochemical analysis, or the necessity of calibrating the geometry of measurement. (author)

  9. Eddy current examination of the nuclear fuel elements of IPR-R1 research reactor

    International Nuclear Information System (INIS)

    Silva, Roger F.; Frade, Rangel T.; Oliveira, Paulo F.; Silva, Marlucio A.; Silva Junior, Silverio F.

    2015-01-01

    Tubes of AISI 304 stainless steel as well as tubes of Aluminum 1100-F are used as cladding of the fuel elements of TRIGA MARK 1 nuclear research reactor. Usually, these tubes are periodically inspected by means of visual test and sipping test. The visual test allows the detection of changes occurred at the external fuel elements surface, such as those promoted by corrosion processes. However, this test method cannot be used for detection of internal discontinuities at the tube walls. Sipping test allows the detection of fuel elements in which the cladding has failed, but it is not able to determine the place where the discontinuity is located. In turn, eddy current testing, an electromagnetic nondestructive test method, allows the detection of discontinuities and monitoring their growth. In this paper, a study about the use of eddy current testing for detection and characterization of discontinuities in the fuel elements cladding is proposed. The study involves the development of probes able to operate in underwater inspections, the design and manufacture of reference standards and the development of a test methodology to perform the evaluations. (author)

  10. Eddy current examination of the nuclear fuel elements of IPR-R1 research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Roger F.; Frade, Rangel T.; Oliveira, Paulo F.; Silva, Marlucio A.; Silva Junior, Silverio F., E-mail: rfs@cdtn.br, E-mail: rtf@cdtn.br, E-mail: pfo@cdtn.br, E-mail: mas@cdtn.br, E-mail: silvasf@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-07-01

    Tubes of AISI 304 stainless steel as well as tubes of Aluminum 1100-F are used as cladding of the fuel elements of TRIGA MARK 1 nuclear research reactor. Usually, these tubes are periodically inspected by means of visual test and sipping test. The visual test allows the detection of changes occurred at the external fuel elements surface, such as those promoted by corrosion processes. However, this test method cannot be used for detection of internal discontinuities at the tube walls. Sipping test allows the detection of fuel elements in which the cladding has failed, but it is not able to determine the place where the discontinuity is located. In turn, eddy current testing, an electromagnetic nondestructive test method, allows the detection of discontinuities and monitoring their growth. In this paper, a study about the use of eddy current testing for detection and characterization of discontinuities in the fuel elements cladding is proposed. The study involves the development of probes able to operate in underwater inspections, the design and manufacture of reference standards and the development of a test methodology to perform the evaluations. (author)

  11. Experimental study of the temperature distribution in the TRIGA IPR-R1 Brazilian research reactor; Investigacao experimental da distribuicao de temperaturas no reator nuclear de pesquisa TRIGA IPR-R1

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Amir Zacarias

    2005-07-01

    The TRIGA-IPR-R1 Research Nuclear Reactor has completed 44 years in operation in November 2004. Its initial nominal thermal power was 30 kW. In 1979 its power was increased to 100 kW by adding new fuel elements to the reactor. Recently some more fuel elements were added to the core increasing the power to 250 kW. The TRIGA-IPR-R1 is a pool type reactor with a natural circulation core cooling system. Although the large number of experiments had been carried out with this reactor, mainly on neutron activation analysis, there is not many data on its thermal-hydraulics processes, whether experimental or theoretical. So a number of experiments were carried out with the measurement of the temperature inside the fuel element, in the reactor core and along the reactor pool. During these experiments the reactor was set in many different power levels. These experiments are part of the CDTN/CNEN research program, and have the main objective of commissioning the TRIGA-IPR-R1 reactor for routine operation at 250 kW. This work presents the experimental and theoretical analyses to determine the temperature distribution in the reactor. A methodology for the calibration and monitoring the reactor thermal power was also developed. This methodology allowed adding others power measuring channels to the reactor by using thermal processes. The fuel thermal conductivity and the heat transfer coefficient from the cladding to the coolant were also experimentally valued. lt was also presented a correlation for the gap conductance between the fuel and the cladding. The experimental results were compared with theoretical calculations and with data obtained from technical literature. A data acquisition and processing system and a software were developed to help the investigation. This system allows on line monitoring and registration of the main reactor operational parameters. The experiments have given better comprehension of the reactor thermal-fluid dynamics and helped to develop numerical

  12. Nondestructive inspection of the tubes of TRIGA IPR-R1 reactor heat exchanger by eddy current testing

    International Nuclear Information System (INIS)

    Silva Junior, Silverio F.; Silva, Roger F.; Oliveira, Paulo F.; Barreto, Erika S.; Ribeiro, Isabela G.; Fraiz, Felipe C.

    2013-01-01

    The IPR-R1 TRIGA MARK 1 reactor is an open pool type reactor, cooled light water. It is used for research activities, personnel training and radioisotopes production, in operation since 1960 at the Nuclear Technology Development Center - CDTN/CNEN. It operates at a maximum thermal power of 100 kW and usually, the fuel cooling is done by natural circulation. If necessary, an external auxiliary cooling system, with a shell-and-tube type heat exchanger, can be used to improve the water heat removal. As part of the ageing management program of the reactor, a nondestructive evaluation of their heat exchanger stainless steel tubes will be performed, in order to verify its integrity. The examinations will be performed using the eddy current test method, which allows the detection and characterization of structural discontinuities in the wall of the tubes, if existing. For this purpose, probes and reference standards were designed and manufactured at CDTN facilities and test procedures were established and validated. In this paper, a description of the proposed infrastructure as well as the test methodology to be used in the examinations are presented and discussed. (author)

  13. FALCAO - a relational database to storaging the variables monitored in the research reactor IEA-R1

    International Nuclear Information System (INIS)

    Gomes Neto, Jose; Andrade, Delvonei Alves de

    2007-01-01

    The objective of this work is to introduce all initial steps for the creation of a relational database, named FALCAO, to support the storaging of the monitored variables in the IEA-R1 research reactor, located in the Instituto de Pesquisas Energeticas e Nucleares, IPEN-CNEN/SP. As introduction, it is considered the modeling importance of the logic diagram and its direct influence in the integrity of the provided information. It is presented the concepts and steps of normalization and denormalization including the entities and relations involved in the logical model. It is also presented the effects of the model rules in the acquisition, loading and availability of the final information, under the performance concept, since the acquisition process, loads and provides lots of information in small intervals of time. The data logical model, considering the desired performance and the sharing information is also presented. (author)

  14. Development of an emergency core cooling system for the converted IEA-R1m research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Torres, Walmir Maximo; Baptista Filho, Benedito Dias; Ting, Daniel Kao Sun [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Dept. de Tecnologia de Reatores]. E-mail: wmtorres@net.ipen.br; bdbfilho@net.ipen.br; dksting@net.ipen.br

    1998-07-01

    This present work describes the development program carried out in the design and construction of the Emergency Core Cooling System for the IEA-R1m Research Reactor, including the system design, the experiments performed to validate the design, manufacturing, installation and commissioning. The experiments were performed in two phases. In the first phase, the spray flow rate and distribution were measured, using a full scale mock-up of the entire core, to establish the spray header geometry and specifications. In the second phase, a test section was fitted with electrically heated plates to simulate the fuel plates. Temperature measurements were carried out to demonstrate the effectiveness of the system to keep the temperatures below the limiting value. The experimental results were shown to the licensing authorities during the certification process. The main difficulties during the system assembly are also described. (author)

  15. Neutronic calculations in core conversion of the IAN-R1 research reactor from MTR HEU to TRIGA LEU fuel

    International Nuclear Information System (INIS)

    Sarta Fuentes, Jose A.; Castiblanco, L.A.

    2003-01-01

    With cooperation of the International Atomic Energy Agency (IAEA), neutronic calculations were carried out for conversion of the Ian-R1 Reactor from MTR-HEU fuel to TRIGA-LEU fuel. In order to establish a staff for neutronic calculation at the Instituto de Cancan's Nucleares y Energia s Alternatives (INEA) a program was established. This program included training, acquisition of hardware, software and calculation for the core with MTR-HEU fuel , enriched nominally to 93% and calculation for several arrangements with the TRIGA-LEU fuel, enriched to 19.7%. The results were verified and compared with several groups of calculation at the Instituto Nacional de Investigaciones Nucleares (ININ) in Mexico, and General Atomics (GA) in United States. As a result of this program, several technical reports have been wrote. (author)

  16. Application of safety checklist to the analysis of the IEA-R1 reactor water retreatment system; Utilizacao do checklist de seguranca na analise do sistema de retratamento de agua do reator IEA-R1

    Energy Technology Data Exchange (ETDEWEB)

    Sauer, Maria Eugenia Lago Jacques; Sara Neto, Antonio Jorge; Lima, Toni Carlos Caboclo de; Ribeiro, Maria Alice Morato [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: melsauer@ipen.br

    2005-07-01

    In 1999, the management of the IEA-R1 Research Reactor (pool type - 5 MWth), located at IPEN/CNEN-SP, started the evaluation of the Reactor Pool Water Retreatment System to identify operational aspects, which could compromise the operators safety. The purpose was to identify and propose enhancements to the system which would be installed to substitute for the existing one. This process was conducted through a qualitative study of the system in operation. This study was carried out by a team composed of specialists in reactor operation, systems maintenance and radiological protection, and one safety analyst. The study consisted, basically, in local inspections to verify the physical and operational conditions of each equipment / component as well as aspects related to maintenance activities of the system. The process control and the operator procedures associated with the retreatment of the reactor pool water were also reviewed. The methodology adopted to develop the study was based in process hazard analysis technique named Safety Checklist. This paper presents a summary of this study and the main results obtained. Some operational and safety problems identified, the prevention and/or correction means to avoid them, and the recommendations and suggestions that have been implemented to the new design of the IEA-R1 Reactor Water Retreatment System, whose installation was concluded in 2003, are also presented. (author)

  17. Considerations about decommissioning of the IEA-R1 research reactor and the future of its installations after shutdown; Consideracoes sobre o descomissionamento do reator de pesquisa IEA-R1 e futuro de suas instalacoes apos o seu desligamento

    Energy Technology Data Exchange (ETDEWEB)

    Frajndlich, Roberto

    2014-07-01

    The IEA-R1 Nuclear Research Reactor, in operation since 1957, in the Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), is one of the oldest research reactors in the world. However at some point in time in the future, as example of the other reactors, it will be shutdown definitively. Before that time actually arrives, the operational organization needs to plan the future of its installations and define the final destination of equipment and radioactive as well as non-radioactive material contained inside the installations. These and other questions should be addressed in the so called Preliminary decommissioning plan of the installation, which is the subject of this work. The work initially presents an over view about the theme and defines the general and specific objectives describing, in succession, the directions that the operating organization should consider for the formulation of a decommissioning plan. The present structure of the Brazilian nuclear sector emphasizing principally the norms utilized in the management of radioactive waste is also presented. A description of principle equipment of the IEA-R1 reactor which constitutes its inventory of radioactive and non-radioactive material is given. The work emphasizes the experience of the reactor technicians, acquired during several reforms and modifications of the reactor installations realized during its useful life time. This experience may be of great help for the decommissioning in the future. An experiment using the high resolution gamma spectrometric method and computer calculation using Monte Carlo theory were performed with the objective of obtaining an estimate of the radioactive waste produced from dismantling of the reactor pool walls. The cost of reactor decommissioning for different choices of strategies was determined using the CERREX code. Finally, a discussion about different strategies is presented. On the basis of these discussions it is concluded that the most advantageous

  18. Development and implementation of a new pneumatic transfer system for materials irradiation at IEA-R1 reactor

    International Nuclear Information System (INIS)

    Fernando, Alberto de Jesus

    2011-01-01

    Pneumatic Transfer Systems (PTS) are classified as mechanical equipment largely operated all over the world for transport of a huge sort of objects, samples and materials located at nearly terminals or even at separated ones. System applicability is often recognized in many activities, such as medicine (hospital settings, clinical analysis labs), industry (steel, automobiles, mining, chemical, food, construction), trading (gas station, movies, supermarkets, banks, e-commerce) and federal agencies (post services, federal courts, public enterprises). In the nuclear settings, PTS shows also a vast array of applications, being a part of radioisotope production, as well as short-lived radiopharmaceuticals, including 67 Ga, 201 Tl, 18 F and 123 I-ultra pure. Besides, PTS are also used at radioactive waste management plants and research institutes that apply neutron activation analysis (NAA). This work was directed toward the design and operation of a new PTS for the IEA-R1 nuclear research reactor settled at Instituto de Pesquisas Energeticas e Nucleares (IPEN) for NAA application. With this aim, it was calculated the charge of reactor core grid plate and sample transport testing. Neutron flux at irradiating position was determined as 3,70 ± 0,26 10 12 n cm -2 s -1 . (author)

  19. Neutron activation analysis at CDTN/CNEN using the IPR-R1 Triga Mark I reactor

    International Nuclear Information System (INIS)

    Menezes, Maria Angela de B.C.; Maretti Junior, Fausto; Kastner, Geraldo Frederico; Amaral, Angela Maria; Souza, Wagner de

    2009-01-01

    This paper describes in summary the activities developed by the Laboratory for Neutron Activation Analysis since the starting up of the IPR-R1 TRIGA Mark I research reactor in 1960. This Laboratory is located at Centro de Desenvolvimento da Tecnologia Nuclear (Nuclear Technology Development Centre) / Comissao Nacional de Energia Nuclear (Brazilian Commission for Nuclear Energy), CDTN/CNEN. The activities of the Laboratory comprise the delayed fission neutron activation analysis, instrumental (comparative and parametric methods) and radiochemical / chemical methods. These methods are responsible for significant percentage of CDTN's analytical demand, meeting the clients' analytical needs and researches developed by the Laboratory, by CDTN and by other institutions. Over the years the work has been linked to the goals of the country and the institutions. Nowadays the neutron activation analysis is responsible for 70% of the analytical demand and the k 0 - Instrumental method for 80% of this demand answering clients' request and researches. In Brazil, CDTN is the only Institute that fully masters the Instrumental Neutron Activation Analysis k 0 -method using its own nuclear reactor. (author)

  20. Neutron flux of 100kW in the irradiation terminals of the IPR-R1 Triga Reactor

    International Nuclear Information System (INIS)

    Zangirolami, Dante Marco

    2009-01-01

    In this work, it was carried out a study of the neutron flux in the IPR-R1 TRIGA reactor irradiation facilities: rotary specimen rack (RSR), pneumatic transfer tube two (PTT2) and the central thimble (CT). The objective was to obtain the neutron flux profile on the RSR, which has forty irradiation positions, and also values for the thermal and epithermal neutron fluxes of some RSR positions and also of the PTT2 and of the CT facility. It was applied the neutron activation analysis of a reference material, Al-Au (0.1%) alloy. Irradiations were performed on 16 different dates. It was concluded that for the RSR, the average value of thermal and epithermal neutron fluxes depends on the vertical position of the reactor control rods. Neutron flux variations along the RSR form a characteristic profile, whose values depend on the location of the irradiation position in the reactor core and on the control rods vertical position. In the RSR, the obtained values of thermal and epithermal neutron flux were (8.1 +- 0.3) x 10 11 n.cm -2 .s -1 , and (3.4 +- 0.2)x10 10 n.cm -2 .s -1 , respectively. For the PTT2 and the CT, the values for the epithermal neutron flux were respectively (3.3 +- 0.2) x 10 9 n.cm -2 .s -1 and (2.6 +- 0.1) x 10 11 n.cm -2 .s -1 . For these facilities, the thermal neutron flux was estimated, and the obtained values were (2.4 +- 0.2) x 10 11 n.cm -2 .s -1 and (2.8 +- 0.1)x10 12 n.cm -2 .s -1 for the PTT2 and the CT, respectively. (author)

  1. Low enriched uranium UAl{sub X}-Al targets for the production of Molybdenum-99 in the IEA-R1 and RMB reactors

    Energy Technology Data Exchange (ETDEWEB)

    Domingos, Douglas B.; Silva, Antonio T. e; Joao, Thiago G.; Silva, Jose Eduardo R. da, E-mail: teixeira@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Nishiyama, Pedro J.B. de O., E-mail: pedro.julio@ctmsp.mar.mil.b [Centro Tecnologico da Marinha em Sao Paulo (CTMSP), SP (Brazil)

    2011-07-01

    The IEA-R1 reactor of IPEN/CNEN-SP in Brazil is a pool type research reactor cooled and moderated by demineralized water and having Beryllium and Graphite as reflectors. In 1997 the reactor received the operating licensing for 5 MW. A new research reactor is being planned in Brazil to replace the IEA-R1 reactor. This new reactor, the Brazilian Multipurpose Reactor (RMB), planned for 30 MW, is now in the conception design phase. Low enriched uranium (LEU) (<20% {sup 235}U) UAl{sub x} dispersed in Al targets are being considered for production of Molybdenum-99 ({sup 99}Mo) by fission. Neutronic and thermal-hydraulics calculations were performed, respectively, to compare the production of {sup 99}Mo for these targets in IEA-R1 reactor and RMB and to determine the temperatures achieved in the UAl{sub x}-Al targets during irradiation. For the neutronic calculations were utilized the computer codes HAMMER-TECHNION, CITATION and SCALE and for the thermal-hydraulics calculations was utilized the computer code MTRCR-IEAR1. (author)

  2. The awareness of the functional and near population with the relation to the research nuclear reactor IEA-R1

    Energy Technology Data Exchange (ETDEWEB)

    Vanni, Silvia R.; Martins, Maria da Penha S. [Centro Tecnologico da Marinha (CTMSP), SP (Brazil); Sabundjian, Gaiane, E-mail: gdjian@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    After the natural accident that hit Japan in the beginning of March of 2011, and that ended into an accident of great proportions in the nuclear installations of Fukushima, it has now the debate over the lack of information that the population in general has over the nuclear energy. The dissemination of information, about the operation and security of the nuclear reactors, has the purpose of softening the effect that the pessimistic atmosphere has over its using. This study was reinforced by the memories of serious consequences due to other nuclear accidents that have already happened (Chernobyl, Three-Mile and Hiroshima/Nagasaki event), bringing insecurity, fear and even revenge from part of the public. Over all, people are not sufficiently informed about the positives and negatives aspects of the nuclear energy. It is necessary the adoption of a clear and aware policy with the population, about the pacific use of nuclear energy. Today, the international and national organizations of control of nuclear energy, the International Atomic Energy Agency (IAEA) and the Comissao Nacional de Energia Nuclear (CNEN), have respectively, published information about this subject using a more professional way and of hard access for the public in general. This work has the goal of checking the level of information that the population of workers and individuals of the close public to the research nuclear reactor IEA-R1, located in the Institute of Nuclear Research (IPEN), University City, Sao Paulo, Brazil, has over it. The way used for this study, involved questionnaires with straight questions and of simple language over the subject, to people of all different social, economic and cultural classes, from 12 to 80 years old. From the results found after this work, it was verified the necessity to elaborate a project of awareness of information and clarification about the nuclear energy, using ways of communication that exist and that are easy for the public to understand. (author)

  3. The awareness of the functional and near population with the relation to the research nuclear reactor IEA-R1

    International Nuclear Information System (INIS)

    Vanni, Silvia R.; Martins, Maria da Penha S.; Sabundjian, Gaiane

    2011-01-01

    After the natural accident that hit Japan in the beginning of March of 2011, and that ended into an accident of great proportions in the nuclear installations of Fukushima, it has now the debate over the lack of information that the population in general has over the nuclear energy. The dissemination of information, about the operation and security of the nuclear reactors, has the purpose of softening the effect that the pessimistic atmosphere has over its using. This study was reinforced by the memories of serious consequences due to other nuclear accidents that have already happened (Chernobyl, Three-Mile and Hiroshima/Nagasaki event), bringing insecurity, fear and even revenge from part of the public. Over all, people are not sufficiently informed about the positives and negatives aspects of the nuclear energy. It is necessary the adoption of a clear and aware policy with the population, about the pacific use of nuclear energy. Today, the international and national organizations of control of nuclear energy, the International Atomic Energy Agency (IAEA) and the Comissao Nacional de Energia Nuclear (CNEN), have respectively, published information about this subject using a more professional way and of hard access for the public in general. This work has the goal of checking the level of information that the population of workers and individuals of the close public to the research nuclear reactor IEA-R1, located in the Institute of Nuclear Research (IPEN), University City, Sao Paulo, Brazil, has over it. The way used for this study, involved questionnaires with straight questions and of simple language over the subject, to people of all different social, economic and cultural classes, from 12 to 80 years old. From the results found after this work, it was verified the necessity to elaborate a project of awareness of information and clarification about the nuclear energy, using ways of communication that exist and that are easy for the public to understand. (author)

  4. Project, installation and operational tests of a pneumatic system for the IEA-R1 reactor materials

    International Nuclear Information System (INIS)

    Fernando, Alberto de Jesus; Madi Filho, Tufic

    2009-01-01

    Pneumatic Transfer Systems (PTS) are equipment broadly and world widely used for the transport, movement and transfer of diverse types of materials, objects and cargo between two or more environments, near or distant from each other [1]. Due to their flexibility and quickness, the system application is present in several areas, such as medicine (hospitals and clinic analyses laboratories); industry (automobile, metallurgy, iron-making. chemical, food production) commerce (gasoline stations, cinemas, supermarkets, banks, tolls, on-line commerce, casinos); public service (public institutions, courts). In the nuclear field, the PTS has, also, a vast application, highlighting its use in the radioisotope and radiopharmaceuticals of short half life production, such as 67 Ga, 201 Tl, 18F and 123 I-ultra pure. The development of this work is directed to the application of the Pneumatic Transfer System in transport and transfer of materials that will be irradiated in the IEA-R1 reactor, located in the Institute of Energetic and Nuclear Research, IPEN/CNEN-SP, for application of the Neutron Activation Analysis (NAA). (author)

  5. Study of human factors and its basic aspects, focusing the operators of IEA-R1 research reactor

    International Nuclear Information System (INIS)

    Martins, Maria da Penha Sanches; Andrade, Delvonei Alves de

    2008-01-01

    Human factors and situational variables, which ca, when modified, interfere in the actions of operators of nuclear installations is studied. This work is focused in the operators of the IEA-R1 research reactor, which is located in the Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Brazil. The accidents in Nuclear Plants have shown that the most serious have occurred due to human failure. This work also considers the item 5.5.3 of CNEN-NN-3.01 standard - 'Actions must be taken to reduce, as much as possible, the human failures that can lead to accidents or even other events which can originate inadvertent or unintentional expositions in any individual'. The model named 'Behavioral Analysis' is adopted. Relevant factors and aspects of the operators' routine are also considered. It is worth to remind that the performance depends on a series of variables, not only on the individual, but also situational, including in these categories; physical variables, work environment, organizational and the social ones. The subjective factors are also considered, such as: attitude, ability, motivation etc., aiming at a global perspective of the situation, which counts on a set of principles for the behaviour analysis and comprehension. After defining the applicability scenario, mechanisms and corrective actions to contribute with the reduction of failures will be proposed. (author)

  6. Study of human factors and its basic aspects, focusing the operators of IEA-R1 research reactor

    International Nuclear Information System (INIS)

    Martins, Maria da Penha Sanches; Andrade, Delvonei Alves de

    2007-01-01

    The objective of this work is the study of human factors and situational variables, which, when modified, can interfere in the work actions of the operators of nuclear installations. This work is focused on the operators of the IEA-R1 research reactor, which is located in the Instituto de Pesquisas Energeticas e Nucleares - IPEN - CNEN/SP. The accidents in Nuclear Plants have shown that the most serious have occurred due to human failure. This work also considers the item 5.5.3 of CNEN-NN-3.01 standard - 'Actions must be taken to reduce, as much as possible, the human failures that may lead to accidents or even other events which may originate inadvertent or unintentional expositions in any individual'. The model named - Behavioral Analysis - is adopted. Relevant factors and aspects of the operators' routine are also considered. It is worth to remind that the performance depends on a series of variables, not only on the individual, but also the situational ones, which include physical, work, environment, organizational and social variables. Subjective factors are also considered, such as: attitude, ability, motivation etc., aiming at a global perspective of the situation, which counts on a set of principles for the behavior analysis and comprehension. After defining the applicability scenario, mechanisms and corrective actions to contribute with the reduction of failures will be proposed. (author)

  7. The evolution of doses in the IEA-R1 reactor environment and tendencies based on the current results; Evolucao das doses no ambiente do Reator IEA-R1 e tendencias com base nos resultados atuais

    Energy Technology Data Exchange (ETDEWEB)

    Toyoda, Eduardo Yoshio

    2016-11-01

    The IPEN / CNEN-SP have a Nuclear Research Reactor-NRR named IEA-R1, in operation from 1957. It is an open swimming pool reactor using light water as shielding, moderator and as cooling, the volume of this pool is 273m{sup 3}.Until 1995 the reactor operated daily at a power of 2,0 MW. From June of that year, after a few safety modifications the reactor began operating in continuous way from Monday to Wednesday without shutdown totalizing 64 hours per week and the power was increased to 4,5MW also. Because of these changes, continuous operation and increased power, workers' doses would tend to increase. In the past several studies were conducted seeking ways to reduce the workers' doses. A study was made on the possibility to introduce a shielding at the top of the reactor core with a hot water layer. Studies have shown that a major limitation for operating a reactor at high power comes from the gamma radiation emitted by the sodium-24. Other elements such as magnesium-27, aluminum-28, Argon-51, contribute considerably to the water activity of the pool. The introduction of a hot water layer on the swimming pool would form a layer of surface, stable and free of radioactive elements with a 1.5m to 2m thickness creates a shielding to radiation from radioactive elements dissolved in water. Optimization studies proved that the installation of the hot layer was not necessary for the regime and the current power reactor operation, because other procedures adopted were more effective. From this decision the Radiological Protection Reactor Team, set up a dose assessment program to ensure them remained in low values based on principles established in national and international standards. The purpose of this paper is to analyze the individual doses of OEI (Occupationally Exposed Individual), which will be checked increasing doses resulting from recent changes in reactor operation regime and suggested viable safety and protection options, in the first instance to

  8. Application of TEMPPC code to the IEA-R1 nuclear reactor core hydrothermal calculations operating at 2 MW for determining the minimal coolant flow

    International Nuclear Information System (INIS)

    Frajndlich, R.; Sousa, J.A. de.

    1985-01-01

    A thermohydraulic study of the IEA-R1 nuclear reactor core on steady-state operating condition and forced convection, is presented. The objective of this calculation is to obtain the minimal flow rate of coolant necessary at the reactor core, limited by the temperature associated to the beginning of nucleate boiling over the fuel plates at a normal operating power (2MW) for a certain inlet coolant temperature. The coolant system safety level is also calculated in this paper, which is divided in three steps: thermohydraulic calculation, without using the uncertainty factors and, after that, considering these factor by two methods: the statistical and the conventional ones. Whichever the method accepted, the results obtained by the program TEMPPC show a great safety margin with respect to the termohydraulic parameters from the IEA-R1 nuclear reactor. (Author) [pt

  9. Obtaining of total and thermal neutron flux in the carousel facility of the TRIGA MARK IPR-R1 reactor using the Monte Carlo transport method

    International Nuclear Information System (INIS)

    Guerra, Bruno Teixeira

    2011-01-01

    The IPR-R1 is a reactor type TRIGA, Mark-I model, manufactured by the General Atomic Company and installed at Nuclear Technology Development Centre (CDTN) of Brazilian Nuclear Energy Commission (CNEN), in Belo Horizonte, Brazil. It is a light water moderated and cooled, graphite-reflected, open-pool type research reactor. IPR-R1 works at 100 kW but it will be briefly licensed to operate at 250 kW. It presents low power, low pressure, for application in research, training and radioisotopes production. The fuel is an alloy of zirconium hydride and uranium enriched at 20% in 235 U. The goal this work is modelling of the IPR-R1 Research Reactor TRIGA using the codes MCNPX2.6.0 (Monte Carlo N-Particle Transport extend) and MCNP5 to the calculating the neutron flux in the carousel facility. In each simulation the sample was placed in a different position, totaling forty positions around of the reactor core. The comparison between the results obtained with experimental values from other work showing a relatively good agreement. Moreover, this methodology is a theoretical tool in validating of the experimental values and necessary for determining neutron flux which can not be accessible experimentally. (author)

  10. Thermal and fast neutron distribution determination in the IPR-R1 reactor core; Levantamento das distribuicoes dos fluxos de neutrons termicos e rapidos no nucleo do reator IPR-R1

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, R R.R.

    1985-06-01

    The work is aimed at obtaining a physical method for neutron flux distribution determination within the reactor core, in order to analyze the project of power increase in the TRIGA IPR-R1 reactor at the Nuclebras Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), located in Belo Horizonte, Minas Gerais, Brazil. The experimental process utilizes the neutron activation technique in impurities of stainless steel welding rods 700 mm long, set in acrylic supports. These rods provide simultaneous information on the thermal and fast neutron fluxes through capture and threshold reactions. The process of detection and counting of activation products utilizes a high resolution Ge (Li) detector and a mechanical scanning device, designed and manufactured at CDTN for burn-up measurements of irradiated fuel elements. Besides its simplicity, the method presents the advantage of substituting high purity imported materials by one easily obtained that also furnishes simultaneous information on the thermal and fast neutron fluxes. Furthermore, values for the absolute thermal neutron flux a long the whole core height are obtained. The procedure consists of the assessment of the thermal neutron flux in a fixed point by means of a conventional detector, and then establishing the correspondence of this measurement with the response of the stainless steel rods. (author). 30 refs, 39 figs, 9 tabs.

  11. Development and implementation of a new pneumatic transfer system for materials irradiation at IEA-R1 reactor; Desenvolvimento e implementacao de um novo sistema pneumatico de transferencia para irradiacao de materiais no reator IEA-R1

    Energy Technology Data Exchange (ETDEWEB)

    Fernando, Alberto de Jesus

    2011-07-01

    Pneumatic Transfer Systems (PTS) are classified as mechanical equipment largely operated all over the world for transport of a huge sort of objects, samples and materials located at nearly terminals or even at separated ones. System applicability is often recognized in many activities, such as medicine (hospital settings, clinical analysis labs), industry (steel, automobiles, mining, chemical, food, construction), trading (gas station, movies, supermarkets, banks, e-commerce) and federal agencies (post services, federal courts, public enterprises). In the nuclear settings, PTS shows also a vast array of applications, being a part of radioisotope production, as well as short-lived radiopharmaceuticals, including 67 Ga, 201 Tl, 18 F and 123 I-ultra pure. Besides, PTS are also used at radioactive waste management plants and research institutes that apply neutron activation analysis (NAA). This work was directed toward the design and operation of a new PTS for the IEA-R1 nuclear research reactor settled at Instituto de Pesquisas Energeticas e Nucleares (IPEN) for NAA application. With this aim, it was calculated the charge of reactor core grid plate and sample transport testing. Neutron flux at irradiating position was determined as 3,70 {+-} 0,26 10{sup 12} n cm{sup -2} s{sup -1}. (author)

  12. Theoretical studies aiming at the IEA-R1 reactor core conversion from high U-235 enrichment to low U-235 enrichment

    International Nuclear Information System (INIS)

    Frajndlich, R.

    1982-01-01

    The research reactors, of which the fuel elements are of MTR type, functions presently, almost in their majority with high U-235 enrichment. The fear that those fuel elements might generate a considerabLe proliferation of nuclear weapons rendered almost mandatory the conversion of highly enriched fuel elements to a low U-235 enrichment. As the IEA-R1 reactor of IPEN is operating with highly enriched fuel elements a study aiming at this conversion was done. The problems related to the conversion and the results obtained, demonstrated the technical viabilty for its realization. (E.G.) [pt

  13. Development of an artificial neural network for nuclear power monitoring and fault detection in the IEA-R1 research reactor at IPEN

    International Nuclear Information System (INIS)

    Bueno, Elaine Inacio; Ting, Daniel Kao Sun; Goncalves, Iraci M.P.

    2005-01-01

    The purpose of this paper is to develop a system to monitor the nuclear power of a reactor using Artificial Neural Networks. The database used in this work was developed using a theoretical model of IEA-R1 Research Reactor. The IEA-R1 is a pool type reactor of 5 MW, cooled and moderated by light water, and uses graphite and beryllium as reflector. To monitor the nuclear power the following variables were chosen: T3 . temperature above the reactor core, T4 . outlet core temperature, FE01 . primary loop flow rate and the nuclear power. The inputs are T3, T4 and FE01 and the output is the nuclear power. It was used several networks using the backpropagation algorithm. The conclusion is that the multiplayer perceptrons networks (MLPs), training by the backpropagation algorithm, can be used to solve this problem. The results obtained with the MLPs networks are satisfactory and the mean square error was in the order of 10 -4 during the network training and in the order of 10 -2 during the network testing. We intend to monitor the other variables of this model using the same methodology, and after this we will use the real database from the system to compare the results obtained with the model. The monitoring of the reactor variables is part of the development of a fault detection and isolation system which is underway and which is, by its turn, part of a comprehensive ageing management program. (author)

  14. Real-Time Monitoring of Neutron Capture Cross Section in the IPR-R1 TRIGA Research Reactor as a Fuel Temperature Function

    Energy Technology Data Exchange (ETDEWEB)

    Palma, D.A.P. [Comissao Nacional de Energia Nuclear, CNEN, General Severiano Street, 90, 22290-901, Rio de Janeiro (Brazil); Mesquita, A.Z.; Souza, R.M.G.P. [Comissao Nacional de Energia Nuclear, CNEN/CDTN, Av. Presidente Antonio Carlos, 6627, 31270-901, Belo Horizonte (Brazil); Martinez, A.S. [Programa de Engenharia Nuclear, COPPE/UFRJ, Av. Horacio Macedo, 2030, Bloco G, 21941- 914, Rio de Janeiro (Brazil)

    2011-07-01

    Nuclear reactor operators have to monitor the behaviour of different nuclear and design parameters that vary in time to ensure the operating safety of the reactor. In recent years several operating parameters for the IPR-R1 TRIGA research reactor were monitored and indicated in real-time by the data acquisition system developed for the reactor, with all the data being stored in a hard disk in the data acquisition computer, to build in this way a database. The goal of this work is to insert in the set of parameters already collected the neutron capture cross sections for the fuel, from the power and temperature numbers obtained in real-time. The experimental data was obtained by using a fuel element instrumented with temperature sensors, located in the core of the IPR-R1 TRIGA research reactor at the CDTN - Centre for Development of Nuclear. This information is useful for the continuous monitoring of the reaction rate in neutron capture. For that, a new analytical formulation is used for the Doppler broadening function proposed by Palma and Martinez which is free from special functions in its functional form and with easy computing implementation. The results obtained were satisfactory from the standpoint of accuracy in comparison with the numerical reference method and indicate that it is possible to carry out real-time monitoring of the neutron capture cross section in the fuel. (author)

  15. Reactivity-worth estimates of the OSMOSE samples in the MINERVE reactor R1-MOX, R2-UO2 and MORGANE/R configurations.

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Z.; Klann, R. T.; Nuclear Engineering Division

    2007-08-03

    An initial series of calculations of the reactivity-worth of the OSMOSE samples in the MINERVE reactor with the R2-UO2 and MORGANE/R core configuration were completed. The calculation model was generated using the lattice physics code DRAGON. In addition, an initial comparison of calculated values to experimental measurements was performed based on preliminary results for the R1-MOX configuration.

  16. Study and project of the new rack with boron for storage of fuel elements burned in the IEA-R1 research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Antonio Carlos Iglesias; Madi Filho, Tufic; Silva, Davilson Gomes da, E-mail: acirodri@ipen.br, E-mail: tmfilho@usp.br, E-mail: dgsilva@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

    2017-07-01

    The IEA-R1 research reactor works 40h weekly with 4.5 Mw power. The storage rack for spent fuel elements has less than half of its initial capacity. Under these conditions (current conditions of reactor operation 32h weekly will have 3 spend fuel by year, then, approximately 3 utilization rate Positions/year). Thus, we will have only about six years of capacity for storage. Whereas the desired service life of the IEA-R1 is at least another 20 years, it will be necessary to increase the storage capacity of spent fuel. Hence, it is necessary to double the wet storage capacity (storage in the IEA-R1 reactor's pool). After reviewing the literature about materials available for use in the construction of the new storage rack with absorber of neutrons, the BoralcanTM (manufactured by 3TMhis) was chosen due to its properties. This work presents studies: (a) for the construction of new storages racks with double of the current capacity using the same place of current storages racks and (b) criticality analysis using the MCNP-5 code. Two American Nuclear Data Library were used: ENDF / B-VI and ENDF / B-VII, and the results obtained for each data bases were compared. These analyzes confirm the possibility of doubling the storage capacity of fuel elements burned in the same place occupied by the current storage rack attending to the IEA-R1 reactor needs and attending the safety requirements according to the National Nuclear Energy Commission - CNEN and the International Atomic Energy Agency (IAEA). To calculate the k{sub eff} were considered new fuel elements (maximum possible reactivity) used in full charge of the storage rack. With the results obtained in the simulation we can conclude that doubling the amount of racks for spent fuel elements are complied with safety limits established in the IAEA standards and CNEN of criticality (keff < 0.95). (author)

  17. Study and project of the new rack with boron for storage of fuel elements burned in the IEA-R1 research reactor

    International Nuclear Information System (INIS)

    Rodrigues, Antonio Carlos Iglesias; Madi Filho, Tufic; Silva, Davilson Gomes da

    2017-01-01

    The IEA-R1 research reactor works 40h weekly with 4.5 Mw power. The storage rack for spent fuel elements has less than half of its initial capacity. Under these conditions (current conditions of reactor operation 32h weekly will have 3 spend fuel by year, then, approximately 3 utilization rate Positions/year). Thus, we will have only about six years of capacity for storage. Whereas the desired service life of the IEA-R1 is at least another 20 years, it will be necessary to increase the storage capacity of spent fuel. Hence, it is necessary to double the wet storage capacity (storage in the IEA-R1 reactor's pool). After reviewing the literature about materials available for use in the construction of the new storage rack with absorber of neutrons, the BoralcanTM (manufactured by 3TMhis) was chosen due to its properties. This work presents studies: (a) for the construction of new storages racks with double of the current capacity using the same place of current storages racks and (b) criticality analysis using the MCNP-5 code. Two American Nuclear Data Library were used: ENDF / B-VI and ENDF / B-VII, and the results obtained for each data bases were compared. These analyzes confirm the possibility of doubling the storage capacity of fuel elements burned in the same place occupied by the current storage rack attending to the IEA-R1 reactor needs and attending the safety requirements according to the National Nuclear Energy Commission - CNEN and the International Atomic Energy Agency (IAEA). To calculate the k eff were considered new fuel elements (maximum possible reactivity) used in full charge of the storage rack. With the results obtained in the simulation we can conclude that doubling the amount of racks for spent fuel elements are complied with safety limits established in the IAEA standards and CNEN of criticality (keff < 0.95). (author)

  18. Impact of uranium concentration reduction in side plates of the fuel elements of IEA-R1 reactor on neutronic and thermal hydraulic analyses

    International Nuclear Information System (INIS)

    Rios, Ilka Antonia

    2013-01-01

    This master thesis presents a study to verify the impact of the uranium concentration reduction in the side plates of the reactor IEA-R1 fuel elements on the neutronic and thermal-hydraulic analyses. To develop such study, a previous IPEN-CNEN/SP research was reproduced by simulating the fuel elements burn-up, with side plate uranium density reduced to 50, 60 and 70% of the standard fuel element plates. This research begins with the neutronic analysis using the computer code HAMMER and the first step consists in the calculation of the cross section of all materials presented at the reactor core, with their initial concentration; the second step consists in the calculation of the fast and thermal neutron group fluxes and power densities for fuel elements using the computer code CITATION. HAMMER output data is used as input data. Once the neutronic analysis is finished and the most critical fuel elements with highest power density have been defined, the thermal-hydraulics analysis begins. This analysis uses MCTR-IEA-R1 thermal-hydraulics model, which equations are solved by commercial code EES. Thermalhydraulics analysis input is the power density data calculated by CITATION: it is considered the highest power density on each fuel element, where there is a higher energy release and, consequently, higher temperatures. This data is used on energy balance equations to calculate temperatures on critical fuel element regions. Reactor operation comparison for three different uranium densities on fuel side plates is presented. Uranium density reduction contributes to the cladding surface temperature to remain below the established limit, as reactor operation safety requirement and it does not affect significantly fuel element final burn-up nor reactor reactivity. The reduction of uranium in the side plates of the fuel elements of the IEA-R1 showed to be a viable option to avoid corrosion problems due to high temperatures. (author)

  19. Survey of the thermal and fast neutron flux distribution in the core of IPR-R1 reactor

    International Nuclear Information System (INIS)

    Guimaraes, R.R.R.

    1985-01-01

    A methodology to obtain the neutron flux distribution inside the core of a reactor is presented, aiming to analyze specifications for increasing reactor power. The activation measurement technique with irradiation of steel eletrodes of 700 mm of lenght, put in acrylic rods was used. In the detection process and in the counting of activation product, a Ge (Li) detector with high resolution and a scanning mechanical system, constructed and projected in CDTN (Nuclear Technology Development Center) were used. (E.G.) [pt

  20. Development of the user Interface of digital simulation system of the operational parameters of the TRIGA IPR-R1 Nuclear Research Reactor

    International Nuclear Information System (INIS)

    Felippe, Adriano de A.M.; Lage, Aldo M.F.; Mesquita, Amir Z.

    2017-01-01

    The development of simulation systems has been increasingly improved to ensure security and reliability to the systems being associated. Computational tools, simulation systems and programming languages increasingly allow the diversification of control systems. With increasing concern about monitoring the key parameters involved in chain reactions inside a nuclear reactor, new technologies are being developed to ensure operations safety. This paper deals with a practical application of a work that is being developed in the Center for the Development of Nuclear Technology - CDTN, which intends to simulate the operation of the TRIGA-IPR-R1 nuclear research reactor using the LabVIEW® software, evaluating the evolution of the neutron flux and other related events. In this paper, the visual interface of the reactor control table, developed through virtual instruments that allow, in a vast repertoire of tools, replicating the panels of the control table in modern screens that can be operated by a user of an analogous form, but still more practical and complete. Since the innovations developed for research reactors can be replicated in power reactors, and because of their lower operating and maintenance costs, projects in this area allow the development of several technologies

  1. The role of the IPR-R1 TRIGA Mark I research reactor in nuclear education and training in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Andrea V.; Mesquita, Amir Z.; Maretti Junior, Fausto; Souza, Rose Mary G.P.; Dalle, Hugo M.; Paiano, Silvestre, E-mail: avf@cdtn.br, E-mail: amir@cdtn.br, E-mail: fmj@cdtn.br, E-mail: souzarm@cdtn.br, E-mail: dallehm@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    The revival of the Brazilian nuclear program has anticipated a large demand for training in nuclear technology. The Nuclear Technology Development Center (CDTN), a research institute of the Brazilian Nuclear Energy Commission (CNEN), offers the Operator Training Course on Research Reactors (CTORP). This course has existed since 1974 and about 258 workers were certificated by CTORP. This article describes the activities of CTORP and presents a proposal for its activities expansion in order to provide the current demand in the nuclear technology. Experimental research projects programs would be created in the postgraduate course at CDTN. In addition to the normal reactor physics topics addressed by CTORP, new subjects such as thermal hydraulic and instrumentation should be added and discussed too. (author)

  2. The role of the IPR-R1 TRIGA Mark I research reactor in nuclear education and training in Brazil

    International Nuclear Information System (INIS)

    Ferreira, Andrea V.; Mesquita, Amir Z.; Maretti Junior, Fausto; Souza, Rose Mary G.P.; Dalle, Hugo M.; Paiano, Silvestre

    2011-01-01

    The revival of the Brazilian nuclear program has anticipated a large demand for training in nuclear technology. The Nuclear Technology Development Center (CDTN), a research institute of the Brazilian Nuclear Energy Commission (CNEN), offers the Operator Training Course on Research Reactors (CTORP). This course has existed since 1974 and about 258 workers were certificated by CTORP. This article describes the activities of CTORP and presents a proposal for its activities expansion in order to provide the current demand in the nuclear technology. Experimental research projects programs would be created in the postgraduate course at CDTN. In addition to the normal reactor physics topics addressed by CTORP, new subjects such as thermal hydraulic and instrumentation should be added and discussed too. (author)

  3. Survey of the thermal and fast neutron flux distribution in the core of IPR-R1 reactor

    International Nuclear Information System (INIS)

    Guimaraes, R.R.R.; Santoro, C.A.B.

    1984-01-01

    A methodology to obtain the neutron flux distribution inside the core is presented, aiming to analize the project of reactor increasing power. The technique of measures by activation with irradiation of steel eletrodes of 700 mm of lenght, put in acrylic rods was used. In the detection process and in the counting of activation product, a Ge(Li) detector with high resolution and a scanning mechanical system, constructed and projected in CDTN (Nuclear Technology Development Center) were used. (E.G.) [pt

  4. Cycle thorium et réacteurs à sel fondu. Exploration du champ des paramètres et des contraintes définissant le "Thorium Molten Salt Reactor"

    OpenAIRE

    Mathieu , Ludovic

    2005-01-01

    Producing nuclear energy in order to reduce the anthropic CO2 emission requires major technological advances. Nuclear plants of IVth generation have to respond to several constraints, as safety improvements, fuel breeding and radioactive waste minimization. For this purpose, it seems promising to use Thorium Cycle in Molten Salt Reactors. Studies on this domain have already been carried out. However, the final concept suffered from serious issues and was discontinued. A new reflection on this...

  5. Neutron field characterization in the installation for BNCT study in the IEA-R1 reactor; Caracterizacao do campo de neutrons na instalacao para estudo em BNCT no reator IEA-R1

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro Junior, Valdeci

    2008-07-01

    This work aims to characterize the mixed neutron and gamma field, in the sample irradiation position, in a research installation for Boron Neutron Capture Therapy (BNCT), in the IPEN IEA-R1 reactor. The BNCT technique has been studied as a safe and selective option in the treatment of resistant cancerigenous tumors or considered non-curable by the conventional techniques, for example, the Glioblastoma Multiform - a brain cancerigenous tumor. Neutron flux measurements were carried out: thermal, resonance and fast, as well as neutron and gamma rays doses, in the sample position, using activation foils detectors and thermoluminescent dosimeters. For the determination of the neutron spectrum and intensity, a set of different threshold activation foils and gold foils covered and uncovered with cadmium irradiated in the installation was used, analyzed by a high Pure Germanium semiconductor detector, coupled to an electronic system suitable for gamma spectrometry. The results were processed with the SAND-BP code. The doses due to gamma and neutron rays were determined using thermoluminescent dosimeters TLD 400 and TLD 700 sensitive to gamma and TLD 600, sensitive to neutrons. The TLDs were selected and used for obtaining the calibration curves - dosimeter answer versus dose - from each of the TLD three types, which were necessary to calculate the doses due to neutron and gamma, in the sample position. The radiation field, in the sample irradiation position, was characterized flux for thermal neutrons of 1.39.10{sup 8} {+-} 0,12.10{sup 8} n/cm{sup 2}s the doses due to thermal neutrons are three times higher than those due to gamma radiation and confirm the reproducibility and consistency of the experimental findings obtained. Considering these results, the neutron field and gamma radiation showed to be appropriated for research in BNCT. (author)

  6. Specific induced activity profile at the rotary specimen rack of IPR-R1 TRIGA reactor after the introduction of a new pneumatic transfer tube

    International Nuclear Information System (INIS)

    Souza, Luiz Claudio Andrade; Zangirolami, Dante Marco; Maretti Junior, Fausto; Ferreira, Andrea Vidal

    2011-01-01

    The IPR-R1 TRIGA nuclear reactor is located in Belo Horizonte, Brazil, at the Nuclear Technology Development Center (Centro de Desenvolvimento da Tecnologia Nuclear, CDTN) of the National Committee on Nuclear Energy (Comissao Nacional de Energia Nuclear, CNEN). One of its irradiation devices is the rotary specimen rack (RSR), outside the reactor core, with forty irradiation positions arranged in a cylindrical geometry. In a previous work, the neutron fluence rate distribution at the RSR and its variation under different irradiation conditions were evaluated by means of specific induced activity measurements in samples of Al-0.1%Au reference material. Since then the core's configuration has been altered with the (re)introduction of another irradiation device, the pneumatic transfer tube 1 (PT-1). This paper aims at identifying and quantifying any changes in neutron fluence that such modification may have caused. (author)

  7. Automation of the computational programs and codes used in the methodology of neutronic and thermohydraulic calculation for the IEA-R1 nuclear reactor

    International Nuclear Information System (INIS)

    Stefani, Giovanni Laranjo de

    2009-01-01

    This work proceeds the elaboration of a computational program for execution of various neutron and thermalhydraulic calculation methodology programs of the IEA-R1-Sao Paulo, Brazil, making the process more practical and safe, besides transforming de output data of each program an automatic process. This reactor is largely used for production of radioisotopes for medical use, material irradiation, personnel training and also for basic research. For that purposes it is necessary to change his core configuration in order to adapt the reactor for different uses. The work will transform various existent programs into subroutines of a principal program, i.e.,a program which call each of the programs automatically when necessary, and create another programs for manipulation the output data and therefore making practical the process

  8. Thermal, thermo-hydraulic and thermo-mechanic analysis for fuel elements of IEA-R1 reactor at 5MW

    International Nuclear Information System (INIS)

    Teixeira e Silva, A.; Silva Macedo, L.V. da

    1989-01-01

    In connection with the on going conversion of IEA-R1 Research Reactor, operated by IPEN-CNEN/SP, from the use of highly enriched uranium (HEU) fuel to the use of low enriched uranium (LEU) fuel, steady-state thermal and thermo-hydraulic analysis of both existing HEU and proposed LEU cores under 2 MW operating conditions have been carried out. Keeping in mind the possibility of power upgrading, steady-state thermal, thermo-hydraulic and thermomechanical analysis of proposed LEU core under 5 MW operating conditions have also been carried out. The thermal and thermo-hydraulic analysis at 2 MW show that the conversion of the existing HEU core to be proposed LEU core will not change the reactor safety margins. Although the upgrading of the reactor power to 5 MW will result in safety margins lower than in case of 2MW, these will be still sufficient for optimum operation and safe behaviour. The thermomechanical analysis at 5 MW show that the thermal stresses induced in the fuel element will satisfy the design limits for mechanical strenght and elastic stability. (author) [pt

  9. Implementation of the optimization for the methodology of the neutronic calculation and thermo-hydraulic in IEA-R1 reactor

    International Nuclear Information System (INIS)

    Stefani, Giovanni Laranjo de; Conti, Thadeu das Neves; Fedorenko, Giuliana G.; Castro, Vinicius A.; Maio, Mireia F.; Santos, Thiago Augusto dos

    2011-01-01

    This work objective was to create a manager program that would automate the programs and computer codes in use for neutronic calculation and thermo-hydraulic in IEA-R1 reactor thus making the process for calculation of safety parameters and for configuration change up to 98% faster than that used in the reactor today. This process was tested in combination with the reactor operators and is being implemented by the quality department. The main codes and programs involved in the calculations of configuration change are Leopard, Hammier-Technion, Twodb, Citation and Cobra. Calculations of delayed neutron and criticality coefficients given in the process of safety parameters calculation are given by the Hammer-Technion and Citation in a process that involves about eleven repetitions so that it meets all the necessary conditions (such different temperatures of the moderator and fuel). The results are entirely consistent with the expected and absolutely the same as those given by manual process. Thus the work shows its reliability as well the advantage of saving time, once a process that could take up to four hours was turned in one that takes around five minutes when done in a home computer. Much of this advantage is due to the fact that were created subprograms to treat the output of each program used and transform them into the input of the other programs, removing from it the intermediate essential data for this to occur, thus avoiding also a possible human error by handling the various data supplied. (author)

  10. Thermal power calibration of the TRIGA Mark I IPR-R1 reactor during the upgrading tests to 250 kW

    International Nuclear Information System (INIS)

    Mesquita, Amir Zacarias; Maretti, Fausto Junior; Rezende, Hugo Cesar

    2002-01-01

    This paper presents the results and the methodology used to calibrate the thermal power of the TRIGA MARK I IPR-R1 Reactor in CDTN, Belo Horizonte, Brazil. This calibration was realized during the operation tests carried out to allow the reactor power upgrade from the current 100 kW to 250 kW. The methodology consisted in the measurement of the inlet and outlet temperature and the water flow in the primary cooling loop. The thermal balance together with the thermal losses gave the thermal power. There were made three sequences of tests. The first rising of the thermal power was made with the usual configuration of the core (59 fuel elements). After the changing of the ion chambers position and the control rod and the increase of the number of fuels (63 fuel elements), a new evaluation of the thermal power was accomplished, having been obtained a thermal power of 234 kW, for an indication of 250 kW in the lineal channel. After the return of the core to the initial configuration (59 fuel elements), it took place a new test, getting back the reactor to the power level of 100 kW. (author)

  11. Optimization of neutronic characteristics of U3Si2 low enrichment fuel elements for a new design of IEA-R1 reactor core

    International Nuclear Information System (INIS)

    Mai, L.A.; Maiorino, J.R.; Gouvea, E.A.

    1989-01-01

    This work shows a study of neutronic optimization of U 3 Si 2 -Al low enrichment fuel element. This study has a goal to propose a optimized Core to be used in the research reactor IEA-R1. The external dimensions of the fuel element were maintained as constraints and the loss of reactivity along fuel life-time was defined as 'objective function', and it has been minimized by varying the fuel element dimensions. Cell calculations were made with HAMMER-TECH /3/ Code, for burnups up to 50% of U-235 initial mass. The Computer values of the objective function for several combinations of fuel element dimensions were fitted by a surface using the SAS system /9/, and it has been minimized by a Harwell subroutine /10/. (author) [pt

  12. Feasibility study of application of Prompt Gamma Neutron Activation Analysis (PGNAA) method in TRIGA IPR-R1 reactor; Estudo da viabilidade de aplicação do método Prompt Gamma Neutron Activation Analysis (PGNAA) no reator TRIGA IPR-R1

    Energy Technology Data Exchange (ETDEWEB)

    Guerra, Bruno Teixeira

    2016-07-01

    The TRIGA Mark I IPR-R1 research reactor is located at Nuclear Technology Development Centre (CDTN), Brazilian Commission for Nuclear Energy (CNEN), in Belo Horizonte, Brazil. The reactor operates at 100 kW but the core configuration allows the increasing of the power up to 250 kW. It has been applied research, training and radioisotopes production. The establishment of the Prompt Gamma Neutron Activation Analysis (PGNAA) method at the TRIGA IPR-R1 reactor will significantly increase the types of matrices analysed as well as the number of chemical elements. Additionally it will complement the neutron activation analysis. This work presents a proposed design of a PGNAA facility to be installed at the TRIGA IPR-R1. The proposed design is based on a tube as a neutron guide from the reactor core, inside the reactor pool, 6 m below the room’s level where shall be located the rack containing the set sample/detector/shielding. Thus, the aim of this study is to verify the feasibility to establish the PGNAA method in IPR-R1 through theoretical study applying the Monte Carlo code. The feasibility of establishing the PGAA method at the IPR-R1 installations was evaluated through of the calculations of neutron flux, radioactive capture reaction rates and detection limits for some isotopes. According to the obtained results, it can be concluded that is possible to establish the PGAA method at the IPR-R1 reactor, even with some restrictions in its theoretical design calculated by MCNP. (author)

  13. Eddy current examination of the nuclear fuel elements with aluminum 1100-F cladding of IPR-R1 research reactor: An initial study

    International Nuclear Information System (INIS)

    Silva, Roger F. da; Silva Júnior, Silvério F. da; Frade, Rangel T.; Rodrigues, Juliano S.

    2017-01-01

    Tubes of aluminum 1100-F as well as tubes of AISI 304 stainless steel are used as cladding of the fuel elements of TRIGA IPR-R1 nuclear research reactor. Usually, these tubes are inspected by means of visual test and sipping test. The visual test allows the detection of changes occurred at the external fuel elements surface, such as those promoted by corrosion processes. However, this test method cannot be used for detection of internal discontinuities at the tube walls. Sipping test allows the detection of fuel elements whose cladding has failed, but it is not able to determine the place where the discontinuity is located. On the other hand, eddy current testing, an electromagnetic nondestructive test method, allows the detection of discontinuities and monitoring their growth. In previous works, the application of eddy current testing to evaluate the AISI 304 cladding fuel elements of TRIGA IPR-R1 was studied. In this paper, it is proposed an initial study about the use of eddy current testing for detection and characterization of discontinuities in the aluminum 1100-F fuel elements cladding. The study includes the development of probes and the design and manufacture of reference standards. (author)

  14. Eddy current examination of the nuclear fuel elements with aluminum 1100-F cladding of IPR-R1 research reactor: An initial study

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Roger F. da; Silva Júnior, Silvério F. da; Frade, Rangel T. [Centro de Desenvolvimento da Tecnologia Nucelar (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Rodrigues, Juliano S., E-mail: rfs@cdtn.br, E-mail: silvasf@cdtn.br, E-mail: rtf@cdtn.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2017-07-01

    Tubes of aluminum 1100-F as well as tubes of AISI 304 stainless steel are used as cladding of the fuel elements of TRIGA IPR-R1 nuclear research reactor. Usually, these tubes are inspected by means of visual test and sipping test. The visual test allows the detection of changes occurred at the external fuel elements surface, such as those promoted by corrosion processes. However, this test method cannot be used for detection of internal discontinuities at the tube walls. Sipping test allows the detection of fuel elements whose cladding has failed, but it is not able to determine the place where the discontinuity is located. On the other hand, eddy current testing, an electromagnetic nondestructive test method, allows the detection of discontinuities and monitoring their growth. In previous works, the application of eddy current testing to evaluate the AISI 304 cladding fuel elements of TRIGA IPR-R1 was studied. In this paper, it is proposed an initial study about the use of eddy current testing for detection and characterization of discontinuities in the aluminum 1100-F fuel elements cladding. The study includes the development of probes and the design and manufacture of reference standards. (author)

  15. Development of an artificial neural network for monitoring and diagnosis of sensor fault and detection in the IEA-R1 research reactor at IPEN

    International Nuclear Information System (INIS)

    Bueno, Elaine Inacio

    2007-01-01

    The increasing demand on quality in production processes has encouraged the development of several studies on Monitoring and Diagnosis Systems in industrial plant, where the interruption of the production due to some unexpected change can bring risk to the operator's security besides provoking economic losses, increasing the costs to repair some damaged equipment. Because of these two points, the economic losses and the operator's security, it becomes necessary to implement Monitoring and Diagnosis Systems. In this work a Monitoring and Diagnosis Systems was developed based on the Artificial Neural Networks methodology. This methodology was applied to the IEA-R1 research reactor at IPEN. The development of this system was divided in three stages: the first was dedicated to monitoring, the second to the detection and the third to diagnosis of failures. In the first stage, several Artificial Neural Networks were trained to monitor the temperature variables, nuclear power and dose rate. Two databases were used: one with data generated by a theoretical model and another one with data to a typical week of operation of the IEA-R1 reactor. In the second stage, the neural networks used to monitor the variables were tested with a fault database. The faults were inserted artificially in the sensors signals. As the value of the maximum calibration error for special thermocouples couples is ± 0,5 deg C, it had been inserted faults of ±1 deg C in the sensor for the reading of the variables T3 and T4. In the third stage was developed a Fuzzy System to carry out the faults diagnosis, where were considered three conditions: a normal condition, a fault of -1 deg C , and a fault of +1 deg C . This system will indicate which thermocouple is faulty. (author)

  16. Development of an artificial neural network for monitoring and diagnosis of sensor fault and detection in the IEA-R1 research reactor at IPEN

    Energy Technology Data Exchange (ETDEWEB)

    Bueno, Elaine Inacio [Centro Federal de Educacao Tecnologica de Sao Paulo (CEFET/SP), Guarulhos, SP (Brazil). Unidade Guarulhos]. E-mail: ebueno@cefetsp.br; Ting, Daniel Kao Sun; Goncalves, Iraci M.P. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mails: dksting@ipen.br; martinez@ipen.br

    2007-07-01

    The increasing demand on quality in production processes has encouraged the development of several studies on Monitoring and Diagnosis Systems in industrial plant, where the interruption of the production due to some unexpected change can bring risk to the operator's security besides provoking economic losses, increasing the costs to repair some damaged equipment. Because of these two points, the economic losses and the operator's security, it becomes necessary to implement Monitoring and Diagnosis Systems. In this work a Monitoring and Diagnosis Systems was developed based on the Artificial Neural Networks methodology. This methodology was applied to the IEA-R1 research reactor at IPEN. The development of this system was divided in three stages: the first was dedicated to monitoring, the second to the detection and the third to diagnosis of failures. In the first stage, several Artificial Neural Networks were trained to monitor the temperature variables, nuclear power and dose rate. Two databases were used: one with data generated by a theoretical model and another one with data to a typical week of operation of the IEA-R1 reactor. In the second stage, the neural networks used to monitor the variables were tested with a fault database. The faults were inserted artificially in the sensors signals. As the value of the maximum calibration error for special thermocouples couples is {+-} 0,5 deg C, it had been inserted faults of {+-}1 deg C in the sensor for the reading of the variables T3 and T4. In the third stage was developed a Fuzzy System to carry out the faults diagnosis, where were considered three conditions: a normal condition, a fault of -1 deg C , and a fault of +1 deg C . This system will indicate which thermocouple is faulty. (author)

  17. Development of an artificial neural network for monitoring and diagnosis of sensor fault and detection in the IEA-R1 research reactor at IPEN

    International Nuclear Information System (INIS)

    Bueno, Elaine Inacio

    2006-01-01

    The increasing demand on quality in production processes has encouraged the development of several studies on Monitoring and Diagnosis Systems in industrial plant, where the interruption of the production due to some unexpected change can bring risk to the operator's security besides provoking economic losses, increasing the costs to repair some damaged equipment. Because of these two points, the economic losses and the operator's security, it becomes necessary to implement Monitoring and Diagnosis Systems. In this work, a Monitoring and Diagnosis Systems was developed based on the Artificial Neural Networks methodology. This methodology was applied to the IEA-R1 research reactor at IPEN. The development of this system was divided in three stages: the first was dedicated to monitoring, the second to the detection and the third to diagnosis of failures. In the first stage, several Artificial Neural Networks were trained to monitor the temperature variables, nuclear power and dose rate. Two databases were used: one with data generated by a theoretical model and another one with data to a typical week of operation of the IEA-R1 reactor. In the second stage, the neural networks used to monitor the variables was tested with a fault database. The faults were inserted artificially in the sensors signals. As the value of the maximum calibration error for special thermocouples is ±0,5 deg C, it had been inserted faults of ± 10 C in the sensors for the reading of the variables T3 and T4. In the third stage a Fuzzy System was developed to carry out the faults diagnosis, where were considered three conditions: a normal condition, a fault of 1 0 C , and a fault of + 10 C . This system will indicate which thermocouple is faulty. (author)

  18. Commissioning of the STAR test section for experimental simulation of loss of coolant accident using the EC-208 instrumented fuel assembly of the IEA-R1 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Maprelian, Eduardo; Torres, Walmir M.; Prado, Adelk C.; Umbehaun, Pedro E.; Franca, Renato L.; Santos, Samuel C.; Macedo, Luiz A.; Sabundjian, Gaiane, E-mail: emaprel@ipen.br, E-mail: wmtorres@ipen.br, E-mail: acprado@ipen.br, E-mail: umbehaun@ipen.br, E-mail: rlfranca@ipen.br, E-mail: samuelcs@ipen.br, E-mail: lamacedo@ipen.br, E-mail: gdjian@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SO (Brazil)

    2015-07-01

    The three basic safety functions of Research Reactors (RR) are the safe shutdown of the reactor, the proper cooling of the decay heat of the fuel elements and the confinement of radioactive materials. Compared to Nuclear Power Reactors, RR power release is small, yet its three safety functions must be met to ensure the integrity of the reactor. During a loss of coolant accident (LOCA) in pool type RR, partial or complete loss of pool water may occur, with consequent partial or complete uncovering of the fuel assemblies. In such an accident, the decay heat removal safety function must not be compromised. The Test Section for Experimental Simulation of Loss of Coolant Accident (STAR) is in commissioning phase. This test section will provide experimental data on partial and total uncovering of the EC-208 instrumented fuel assembly (IFA) irradiated in the IEA-R1. Experimental results will be useful in validation of computer codes for RR safety analysis, particularly on heat removal efficiency aspects (safety function) in accident conditions. STAR comprises a base on which is installed the IFA, the cylindrical stainless steel hull, the compressed air system for the test section emptying and refilling, and the instrumentation for temperature and level measurements. The commissioning tests or pre-operational check, consist of several preliminary tests to verify experimental procedures, the difficulties during assembling of STAR in the pool, the difficulties in control the emptying and refilling velocities, as well as, the repeatability capacity, tests of equipment, valves and systems and tests of instrumentation and data acquisition system. Safety, accuracy and easiness of operation will be checked. (author)

  19. Design and construction of an irradiation apparatus with controlled atmosphere and temperature for radiation damage evaluation of nuclear materials in the IEA-R1 research reactor

    International Nuclear Information System (INIS)

    Lucki, Georgi; Silva, Jose Eduardo Rosa da; Castanheira, Myrthes; Terremoto, Luis Antonio Albiac; Teodoro, Celso Antonio; Silva, Antonio Teixeira e; Damy, Margaret de Almeida

    2005-01-01

    A material irradiation apparatus CIMAT (Capsula de Irradiacao de Materiais) with controlled temperature and atmosphere is described. The device was specifically designed to perform experiments inside the core of the IEA-R1 swimming pool reactor and allows fast neutron (E=1 MeV) irradiations of multiple miniature metallic samples at temperature between 100 deg C and 500 deg C, in Argon or Helium atmosphere to inhibit corrosion. The aim of CIMAT is to make a comparative assessment of Radiation Embrittlement (RE) on the AS 508 cl.3 steel, of different origins (ELETROMETAL-Brazil and VITCOVICE-Chekia) used in Pressure Vessels (PV) of PWR, for fluence of 10 exp 19 nvt at 300 C, by means of mechanical post irradiation evaluation. Previous characterization of non-irradiated samples of these materials is presented. In situ electrical and magnetic measurements, at high temperatures, are foreseen to be made with this apparatus. Extensive temperature stability and leak-tightness tests performed in the reactor swimming pool have proven the CIMAT to be intrinsically safe and operational. (author)

  20. Non destructive burn up determination of IEA-R1 reactor fuel elements by gamma-ray spectrometry using a Ge(Li) detector

    International Nuclear Information System (INIS)

    Madi Filho, T.

    1982-01-01

    A non destructive determination of burn up of low (IEA-14) and high (IEA-80) activity fuel elements used in the IEA-R1 pool reactor was made from the measured distribution of the Cs-137 gamma-ray activity in these elements. For both series of measurements a 73,7 c.c. Ge(Li) detector was used in 'well collimated' geometry. Where as IEA-14, removed from the reactor some 20 years, showed a gamma-ray spectrum essentially due to Cs-137, IEA-80, with a cooling time of 5 years, showed a more complex spectrum due to the greater number of fission products remaining. The S.I out-of-pool assembly was calibrated using Cs-137 and Co-60 point and Ag-110m plane sources. These measurements provided the necessary constants used to calculate fuel burn-up from measured relative activity distributions of fuel elements. Detailed fuel plate transmission measurements made with the Cs-137 source showed the plates to be highly homogeneous. High activity fuel elements were measured in the S.II in-pool assembly in which the detector was locate on the moveable pool bridge and the test element was positioned immediately below the detector 2.17m below the pool surface. Measurements made in the S.II assembly were normalised with respect to the measured activity of the IEA-14 element. The measured burn up of the IEA-14 and IEA-80 elements obtained in this work is 3.22.10 - 3 gms and 24.44gms. These values may be compared with respective values of 2.63.10 - 3 gms and 61.11gms given by 'total reactor energy/flux distribution' calculations. Calculated errors for the U-235 burn up are 7.4% (IEA-14) and 10.1% (IEA-80). A detailed evaluation of the errors associated with both sets of measurements is given. (Author) [pt

  1. Calibration of SPND/Rhodium device for mapping the neutron fluence in the IEA-R1 reactor by means of the activation foil method; Calibracao de um dispositivo de mapeamento de fluxo de neutrons - SNPD/Rodio no reator IEA-R1, por meio do metodo de ativacao de folhas

    Energy Technology Data Exchange (ETDEWEB)

    Ricci Filho, Walter; Dias, Mauro S.; Tondin, Julio B.M.; Koskinas, Marina F. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    2002-07-01

    The IEA-R1 reactor has undergone a modernization to increase its operating power to 5 MW, in order to allow a more efficient production of radioisotopes. The objective of this work is to provide the reactor with flux monitoring device using a rhodium Self-Powered Neutron Detector (SPND). The work presents the results obtained with Rhodium-SPND in several irradiation positions inside the reactor core. A calibration procedure has been performed by means of {sup 197} Au activation foils, with and without cadmium cover, in order do measure the thermal and epithermal neutron fluxes. (author)

  2. Neutronic and thermal-hydraulic analysis of a device for irradiation of LEU UAlx-Al targets for 99Mo production in the IEA-R1 reactor

    International Nuclear Information System (INIS)

    Nishiyama, Pedro Julio Batista de Oliveira

    2012-01-01

    Technetium-99m ( 99m Tc), the product of radioactive decay of molybdenum-99 ( Mo), is one of the most widely used radioisotope in nuclear medicine, covering approximately 80% of all radiodiagnosis procedures in the world. Nowadays, Brazil requires an amount of about 450 Ci of 99 Mo per week. Due to the crisis and the shortage of 99 Mo supply chain that has been observed on the world since 2008, IPEN/CNEN-SP decided to develop a project to produce 99 Mo through fission of uranium-235. The objective of this dissertation was the development of neutronic and thermal-hydraulic calculations to evaluate the operational safety of a device for 99 Mo production to be irradiated in the IEA-Rl reactor core at 5 MW. In this device will be placed ten targets of UAl x -Al dispersion fuel with low enriched uranium (LEU) and density of 2.889 gU/cm 3 . For the neutronic calculations were utilized the computer codes HAMMER-TECHNION and CITATION and the maximum temperatures reached in the targets were calculated with the code MTRCR-IEA-R1. The analysis demonstrated that the device irradiation will occur without adverse consequences to the operation of the reactor. The total amount of 99 Mo was calculated with the program SCALE and considering that the time needed for the chemical processing and recovering of the 99 Mo will be five days after the irradiation, we have that the 99 Mo activity available for distribution will be 176 Ci for 3 days of irradiation, 236 Ci for 5 days of irradiation and 272 Ci for 7 days of targets irradiation. (author)'

  3. Impurities determination on nuclear fuel element components for the IEA-R1 research reactor by analytical methods based on ED-XRF and ICP-OES

    International Nuclear Information System (INIS)

    Reis, Edson Luis Tocaia dos; Scapin, Marcos; Cotrim, Marycel Elena Barboza; Salvador, Vera Lucia; Pires, Maria Aparecida Faustino

    2009-01-01

    The production of nuclear fuel used in the research reactor at Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP) requires a series of chemical and metallurgical processes. The quality of the end product depends on the control over all the stages of the manufacturing process and over the quality of raw materials employed. In fact, spectrometric methods are increasingly used as quantitative analytical techniques applicable to uranium compounds because of simultaneous determination of several elements with minimum amounts of sample. However, the main obstacle of uranium compounds analysis by spectrometric techniques such as optical emission spectrometry with inductively coupled plasma (ICP-OES) is the complex emission spectrum of uranium. The ICP-OES is not appropriately capable of determining the major elements of interest without initial chemical separation of uranium. In this sense, the use of X-ray fluorescence spectrometry (XRF) has been considered for quantitative determination of main elements with the advantage of not being destructive and not requiring a prior preparation of samples for analysis. Due to the simplicity of this technique, its applicability includes research and quality control in universities, research institutions, petrochemical industries, metallurgy, mining, etc. In this work, some components considered impurities in nuclear fuel element samples used in the IEA-R1 research reactor of IPEN/CNEN-SP were chemically characterized by ICP-OES analysis after chromatography extraction separation by using TBP/XAD-14 system and compared to results obtained by energy dispersive X-ray fluorescence spectrometry (EDXRF) and wavelength dispersive X-ray fluorescence (WDXRF). (author)

  4. Self-organizing maps of Kohonen (SOM) applied to multidimensional monitoring data of the IEA-R1 nuclear research reactor

    International Nuclear Information System (INIS)

    Affonso, Gustavo S.; Pereira, Iraci M.; Mesquita, Roberto N. de; Bueno, Elaine I.

    2011-01-01

    Multivariate statistics comprise a set of statistical methods used in situations where many variables are database space subsets. Initially applied to human, social and biological sciences, these methods are being applied to many other areas such as education, geology, chemistry, physics, engineering, and many others. This spectra expansion was possible due to recent technological development of computation hardware and software that allows high and complex databases to be treated iteratively enabling further analysis. Following this trend, the neural networks called Self-Organizing Maps are turning into a powerful tool on visualization of implicit and unknown correlations in big sized database sets. Originally created by Kohonen in 1981, it was applied to speech recognition tasks. The SOM is being used as a comparative parameter to evaluate the performance of new multidimensional analysis methodologies. Most of methods require good variable input selection criteria and SOM has contributed to clustering, classification and prediction of multidimensional engineering process variables. This work proposes a method of applying SOM to a set of 58 IEA-R1 operational variables at IPEN research reactor which are monitored by a Data Acquisition System (DAS). This data set includes variables as temperature, flow mass rate, coolant level, nuclear radiation, nuclear power and control bars position. DAS enables the creation and storage of historical data which are used to contribute to Failure Detection and Monitoring System development. Results show good agreement with previous studies using other methods as GMDH and other predictive methods. (author)

  5. Evaluation of neutron flux in Al-Au alloy of different dimensions in the TRIGA IPR-R1 reactor using Monte Carlos Method

    International Nuclear Information System (INIS)

    Salome, Jean Anderson Dias

    2012-01-01

    Neutron Activation Analysis technique is applied in several procedures determining chemical elements - range of trace to percentage - in many materials; in radiochemical processes; archaeological and geological studies, in nuclear medicine and biochemical analysis and in forensic cases. It consists in submit a sample to a neutron flux and measure the induced activity by gamma spectrometry. Although it is a very useful method, the technique presents a limitation related to sample dimensions. The technique is applied in samples with micrograms to milligrams, or a few microliters to milliliters, when the density is negligible. In this work, using the Monte Carlo MCNP5 code, the effects of irradiated samples of different dimensions were simulated in the reactor TRIGA IPR-R1 of CDTN/CNEN, evaluating the total and thermal neutron fluxes. The values were compared to experimental values of thermal neutron flux determined for 11 most representative irradiation channels in the rotary rack. Statistical tests were used to evaluate the MCNP models. The results pointed out that a sample with 0.43 cm high, 0.48 cm radius and 1100 g.L -1 density, can be analyzed as it were a punctual sample, like soil sample, without disturbance of thermal neutron in the sample. For the total neutron flux, it can be concluded the same. Besides, 97% of the results are inside 95% confidence interval related to experimental values, as well as, 97% of the results are satisfactory for z-score. It points out the good performance of the modeling. (author)

  6. Self-organizing maps of Kohonen (SOM) applied to multidimensional monitoring data of the IEA-R1 nuclear research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Affonso, Gustavo S.; Pereira, Iraci M.; Mesquita, Roberto N. de, E-mail: rnavarro@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Bueno, Elaine I., E-mail: ebueno@ifsp.gov.b [Instituto Federal de Educacao, Ciencia e Tecnologia de Sao Paulo (IFSP), SP (Brazil)

    2011-07-01

    Multivariate statistics comprise a set of statistical methods used in situations where many variables are database space subsets. Initially applied to human, social and biological sciences, these methods are being applied to many other areas such as education, geology, chemistry, physics, engineering, and many others. This spectra expansion was possible due to recent technological development of computation hardware and software that allows high and complex databases to be treated iteratively enabling further analysis. Following this trend, the neural networks called Self-Organizing Maps are turning into a powerful tool on visualization of implicit and unknown correlations in big sized database sets. Originally created by Kohonen in 1981, it was applied to speech recognition tasks. The SOM is being used as a comparative parameter to evaluate the performance of new multidimensional analysis methodologies. Most of methods require good variable input selection criteria and SOM has contributed to clustering, classification and prediction of multidimensional engineering process variables. This work proposes a method of applying SOM to a set of 58 IEA-R1 operational variables at IPEN research reactor which are monitored by a Data Acquisition System (DAS). This data set includes variables as temperature, flow mass rate, coolant level, nuclear radiation, nuclear power and control bars position. DAS enables the creation and storage of historical data which are used to contribute to Failure Detection and Monitoring System development. Results show good agreement with previous studies using other methods as GMDH and other predictive methods. (author)

  7. Study of human factors, and its basic aspects focusing the IEA-R1 research reactor operators, aiming at the prevention of accidents caused by human failures

    International Nuclear Information System (INIS)

    Martins, Maria da Penha Sanches

    2008-01-01

    This work presents a study of human factors and possible human failure reasons that can cause incidents, accidents and workers exposition, associated to risks intrinsic to the profession. The objective is to contribute with the operators of IEA-R1 reactor located at IPEN CNEN/S P. Accidents in the technological field, including the nuclear, have shown that the causes are much more connected to human failure than to system and equipment failures, what has led the regulatory bodies to consider studies on human failure. The research proposed in this work is quantitative/qualitative and also descriptive. Two questionnaires were used to collect data. The first of them was elaborated from the safety culture attributes which are described by the International Atomic Energy Agency - IAEA. The second considered individual and situational factors composing categories that could affect people in the work area. A carefully selected transcription of the theoretical basis according to the study of human factors was used. The methodology demonstrated a good reliability degree. Results lead to mediate factors which need direct actions concerning the needs of the group and of the individual. This research shows that it is necessary to have a really effective unit of planning and organization, not only to the physical and psychological health issues but also to the safety in the work. (author)

  8. The neutron and gamma-ray dose characterization using the Monte Carlo method to study the feasibility of the Prompt Gamma Activation Analysis technique at IPR-R1 TRIGA reactor in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Guerra, Bruno T.; Soares, Alexandre L.; Grynberg, Suely E.; Menezes, Maria Angela B.C., E-mail: brunoteixeiraguerra@yahoo.com.br, E-mail: menezes@cdtn.br, E-mail: asleal@cdtn.br, E-mail: seg@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2013-07-01

    The IPR-R1 is a reactor type TRIGA, Mark-I model, manufactured by the General Atomic Company and installed at Nuclear Technology Development Centre (CDTN) of Brazilian Nuclear Energy Commission (CNEN), in Belo Horizonte, Brazil. It is a light water moderated and cooled, graphite-reflected, open-pool type research reactor. IPR-R1 works at 100 kW but it will be briefly licensed to operate at 250 kW. It presents low power, low pressure, for application in research, training and radioisotopes production. The fuel is an alloy of zirconium hydride and uranium enriched at 20% in {sup 235}U. The Implementation of the PGNAA (Prompt Gamma Neutron Activation Analysis) Technical at the TRIGA IPR-R1 research reactor of the CDTN will significantly increase in the types of matrices analyzable. A project is underway in order to implement this technique in CDTN. In order of verified the feasibility of the PGNAA at the TRIGA reactor, the MCNP (Monte Carlo N-Particle) method is used to theoretical calculations. This paper presents the results of a preliminary study of the neutron and gamma-ray dose in the room where the reactor is located, in case of implementation of this technique in the IPR-R1. (author)

  9. The neutron and gamma-ray dose characterization using the Monte Carlo method to study the feasibility of the Prompt Gamma Activation Analysis technique at IPR-R1 TRIGA reactor in Brazil

    International Nuclear Information System (INIS)

    Guerra, Bruno T.; Soares, Alexandre L.; Grynberg, Suely E.; Menezes, Maria Angela B.C.

    2013-01-01

    The IPR-R1 is a reactor type TRIGA, Mark-I model, manufactured by the General Atomic Company and installed at Nuclear Technology Development Centre (CDTN) of Brazilian Nuclear Energy Commission (CNEN), in Belo Horizonte, Brazil. It is a light water moderated and cooled, graphite-reflected, open-pool type research reactor. IPR-R1 works at 100 kW but it will be briefly licensed to operate at 250 kW. It presents low power, low pressure, for application in research, training and radioisotopes production. The fuel is an alloy of zirconium hydride and uranium enriched at 20% in 235 U. The Implementation of the PGNAA (Prompt Gamma Neutron Activation Analysis) Technical at the TRIGA IPR-R1 research reactor of the CDTN will significantly increase in the types of matrices analyzable. A project is underway in order to implement this technique in CDTN. In order of verified the feasibility of the PGNAA at the TRIGA reactor, the MCNP (Monte Carlo N-Particle) method is used to theoretical calculations. This paper presents the results of a preliminary study of the neutron and gamma-ray dose in the room where the reactor is located, in case of implementation of this technique in the IPR-R1. (author)

  10. The implementation and evaluation of physical protection system of the IEA-R1 reactor; Implementacao e avaliacao do sistema de protecao fisica do reator IEA-R1

    Energy Technology Data Exchange (ETDEWEB)

    Vaz, Antonio Carlos Alves

    2016-11-01

    The September 11, 2001 terrorist attacks in New York, the accident at the Fukushima nuclear power plant on March 2011 and the recent attacks in Paris on November 2015 are examples of events that justify the efforts of the International Agency of Energy Atomic - IAEA to improve security at nuclear facility. The Brazilian government has been collaborating with this project and investing resources to improve the Physical Protection System - PPS of the nuclear research reactor system, technically is associated with the elements of detection, delay and response. The PPS is an integrated system of people, equipment and procedures used to protect nuclear facilities and radioactive sources against threat, theft or sabotage. The PPS works to avoid, to mitigate or to minimize the consequences caused by these actions. This study evaluates the PPS of the reactor, identifying the vulnerabilities and suggesting ways to improve the system effectiveness. The analyses were based on the methodology developed by Sandia National Laboratories´ security experts in Albuquerque - USA, allowing the system evaluation through hypothetical and probabilistic analyzes; identifying threats, determining the targets and analyzing the possible adversaries paths. From the methodology adopted was obtained the value around 40% for PE indicator, which shows the need to improve the system to minimizing the vulnerabilities. (author)

  11. Survey of nuclear parameters from the TRIGA Mark I IPR R1 Brazilian reactor with concentric configuration aiming the application of K0 neutron activation technique

    International Nuclear Information System (INIS)

    Franco, Milton Batista

    2006-01-01

    This research intended to determine the nuclear parameters a, f, spectral index and neutron temperature in several irradiations positions of the TRIGA Mark 1 IPR-R1 reactor, for use on the parametric method K 0 in the CDTN. K 0 is a monostandard method of neutron activation analysis. It is, on the whole, experimentally simple, flexible and an important tool for accurate and convenient standardization in instrumental multi-element analysis. At the time the parameters were determined at the rotatory rack, lower layer and in the central thimble: alpha was calculated applying the three bare monitor method using 197 Au, 94 Zr and 96 Zr; f determination was done according to the bare bi-isotopic method; neutron temperature was calculated through the direct method using 176 Lu, 94 Zr, 96 Zr and 197 Au and the Westcott's g(Tn) function for the 176 Lu was calculated and the result was interpolated in the Grintakis and Kim (1975) Table, determining the neutron temperature. The procedure to check the parameters consisted in using standard solutions of Au (metal foil, NBS), Lu (LuO 2 , Johnson Mattey Company - JMC) and Zr (ZrO 2 and metal foil, Johnson Mattey Company 99,99% and Zry - 4: 98,14% of Zr, National Bureau of Standard- NBS). Several certified reference materials and two samples of intercomparisons (samples of sediment of the IAEA/ARCAL XXVI project) have been analysed by means of k 0 - INAA in order to verify the efficiency of the method and the quality of the parameters. The certified reference materials were: GXR-2, GXR-5 and GXR-6 of the United States Geological Survey (USGS) and Soil-5, Soil-7 and SL-1 of the International Atomic Energy Agency (IAEA). (author)

  12. Application of the k{sub 0}-INAA method for analysis of biological samples at the pneumatic station of the IEA-R1 nuclear research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Puerta, Daniel C.; Figueiredo, Ana Maria G.; Semmler, Renato, E-mail: dcpuerta@hotmail.com, E-mail: anamaria@ipen.br, E-mail: rsemmler@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Jacimovic, Radojko, E-mail: radojko.jacimovic@ijs.si [Jozef Stefan Institute (JSI), Ljubljana, LJU (Slovenia). Department of Environmental Sciences

    2013-07-01

    As part of the process of implementation of the k{sub 0}-INAA standardization method at the Neutron Activation Laboratory (LAN-IPEN), Sao Paulo, Brazil, this study presents the results obtained for the analysis of short and medium-lived nuclides in biological samples by k{sub 0}-INAA using the program k{sub 0}-IAEA, provided by the International Atomic Energy Agency (IAEA). The elements Al, Ba, Br, Na, K, Mn, Mg, Sr and V were determined with respect to gold ({sup 197}Au) using the pneumatic station facility of the IEA-R1 4.5 MW swimming pool nuclear research reactor, Sao Paulo. Characterization of the pneumatic station was carried out by using the 'bare triple-monitor' method with {sup 197}Au-{sup 96}Zr-{sup 94}Zr. The Certified Reference Material IRMM-530R Al-0.1%Au alloy and high purity zirconium comparators were used. The efficiency curves of the gamma-ray spectrometer used were determined by measuring calibrated radioactive sources at the usually utilized counting geometries. The method was validated by analyzing the reference materials NIST SRM 1547 Peach Leaves, INCT-MPH-2 Mixed Polish Herbs and NIST SRM 1573a Tomato Leaves. The concentration results obtained agreed with certified, reference and recommended values, showing relative errors (bias, %) less than 30% for most elements. The Coefficients of Variation were below 20%, showing a good reproducibility of the results. The E{sub n}-number showed that all results, except Na in NIST SRM 1547 and NIST SRM 1573a and Al in INCT-MPH-2, were within 95% confidence interval. (author)

  13. k{sub 0}-INAA method at the pneumatic station of the IEA-R1 nuclear research reactor. Application to geological samples

    Energy Technology Data Exchange (ETDEWEB)

    Mariano, Davi B.; Figueiredo, Ana Maria G.; Semmler, Renato, E-mail: davimariano@usp.br, E-mail: anamaria@ipen.br, E-mail: rsemmler@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    There is a significant number of analytically important elements, when geological samples are concerned, whose activation products are short-lived (seconds to minutes) or medium-lived radioisotopes (minutes to hours). As part of the process of implementation of the k{sub 0}-INAA standardization method at the Neutron Activation Laboratory (LAN-IPEN), Sao Paulo, Brazil, this study presents the results obtained for the analysis of short and medium-lived nuclides in geological samples by k{sub 0}-INAA using the program k{sub 0}-IAEA, provided by The International Atomic Energy Agency (IAEA). The elements Al, Dy, Eu, Na, K, Mn, Mg, Sr, V and Ti were determined with respect to gold ({sup 197}Au) using the pneumatic station facility of the IEA-R1 5 MW swimming pool nuclear research reactor, Sao Paulo. Characterization of the pneumatic station was carried out by using the -bare triple-monitor- method with {sup 197}Au-{sup 96}Zr-{sup 94}Zr. The Certified Reference Material IRMM-530R Al-0,1% Au alloy, high purity zirconium, Ni and Lu comparators were irradiated. The efficiency curves of the gamma-ray spectrometer used were determined by measuring calibrated radioactive sources at the usually utilized counting geometries. The method was validated by analyzing the reference materials basalt BE-N (IWG-GIT), basalt JB- 1 (GSJ), andesite AGV-1 (USGS), granite GS-N (IWG-GIT), SOIL-7 (IAEA) and sediment Buffalo River Sediment (NIST-BRS-8704), which represent different geological matrices. The concentration results obtained agreed with certified, reference and recommended values, showing relative errors less than 10% for most elements. (author)

  14. Determination of scaling factors to estimate the radionuclide inventory in waste with low and intermediate-level activity from the IEA-R1 reactor

    International Nuclear Information System (INIS)

    Taddei, Maria Helena Tirollo

    2013-01-01

    Regulations regarding transfer and final disposal of radioactive waste require that the inventory of radionuclides for each container enclosing such waste must be estimated and declared. The regulatory limits are established as a function of the annual radiation doses that members of the public could be exposed to from the radioactive waste repository, which mainly depend on the activity concentration of radionuclides, given in Bq/g, found in each waste container. Most of the radionuclides that emit gamma-rays can have their activity concentrations determined straightforwardly by measurements carried out externally to the containers. However, radionuclides that emit exclusively alpha or beta particles, as well as gamma-rays or X-rays with low energy and low absolute emission intensity, or whose activity is very low among the radioactive waste, are generically designated as Difficult to Measure Nuclides (DTMs). The activity concentrations of these DTMs are determined by means of complex radiochemical procedures that involve isolating the chemical species being studied from the interference in the waste matrix. Moreover, samples must be collected from each container in order to perform the analyses inherent to the radiochemical procedures, which exposes operators to high levels of radiation and is very costly because of the large number of radioactive waste containers that need to be characterized at a nuclear facility. An alternative methodology to approach this problem consists in obtaining empirical correlations between some radionuclides that can be measured directly – such as 60 Co and 137 Cs, therefore designated as Key Nuclides (KNs) – and the DTMs. This methodology, denominated Scaling Factor, was applied in the scope of the present work in order to obtain Scaling Factors or Correlation Functions for the most important radioactive wastes with low and intermediate-activity level from the IEA-R1 nuclear research reactor. (author)

  15. Impact of uranium concentration reduction in side plates of the fuel elements of IEA-R1 reactor on neutronic and thermal hydraulic analyses; Impacto da reducao na concentracao de uranio nas placas laterais dos elementos combustiveis do reator IEA-R1 nas analises neutronica e termo-hidraulica

    Energy Technology Data Exchange (ETDEWEB)

    Rios, Ilka Antonia

    2013-09-01

    This master thesis presents a study to verify the impact of the uranium concentration reduction in the side plates of the reactor IEA-R1 fuel elements on the neutronic and thermal-hydraulic analyses. To develop such study, a previous IPEN-CNEN/SP research was reproduced by simulating the fuel elements burn-up, with side plate uranium density reduced to 50, 60 and 70% of the standard fuel element plates. This research begins with the neutronic analysis using the computer code HAMMER and the first step consists in the calculation of the cross section of all materials presented at the reactor core, with their initial concentration; the second step consists in the calculation of the fast and thermal neutron group fluxes and power densities for fuel elements using the computer code CITATION. HAMMER output data is used as input data. Once the neutronic analysis is finished and the most critical fuel elements with highest power density have been defined, the thermal-hydraulics analysis begins. This analysis uses MCTR-IEA-R1 thermal-hydraulics model, which equations are solved by commercial code EES. Thermalhydraulics analysis input is the power density data calculated by CITATION: it is considered the highest power density on each fuel element, where there is a higher energy release and, consequently, higher temperatures. This data is used on energy balance equations to calculate temperatures on critical fuel element regions. Reactor operation comparison for three different uranium densities on fuel side plates is presented. Uranium density reduction contributes to the cladding surface temperature to remain below the established limit, as reactor operation safety requirement and it does not affect significantly fuel element final burn-up nor reactor reactivity. The reduction of uranium in the side plates of the fuel elements of the IEA-R1 showed to be a viable option to avoid corrosion problems due to high temperatures. (author)

  16. Estimative of core damage frequency in IPEN's IEA-R1 research reactor (PSA level 1) due to the initiating event of loss of coolant caused by large rupture in the pipe of the primary circuit

    International Nuclear Information System (INIS)

    Hirata, Daniel Massami

    2009-01-01

    This work applies the methodology of probabilistic safety assessment level 1 to the research reactor IEA-R1 IPEN-CNEN/SP. Two categories of identified initiating events of accidents in the reactor are studied: loss of flow and loss of primary coolant. Among the initiating events, blockage of flow channel and loss of cooling fluid by major pipe rupture in the primary circuit are chosen for a detailed analysis. The event tree technique is used to analyze the evolution of the accident, including the actuation or the fail of actuation of the safety systems and the reactor damages. Using the fault tree the reliability of the following reactor safety systems is evaluated: reactor shutdown system, isolation of the reactor pool, emergency core cooling system (ECCS) and the electric system. Estimative for the frequency of damage to the reactor core and the probability of failure of the analyzed systems are calculated. The estimated values for the frequencies of core damage are within the expected margins and are of the same order of magnitude as those found for similar reactors. The reliability of the reactor shutdown system, isolation of the reactor pool and ECCS are satisfactory for the conditions these systems are required. However, for the electric system it is suggested an upgrade to increase its reliability. (author)

  17. Neutronic, thermal-hydraulics and accident analysis calculations for an irradiation device to be used in the qualification process of dispersion fuels in the IEA-R1 research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Domingos, Douglas Borges; Silva, Antonio Teixeira e; Umbehaun, Pedro Ernesto; Silva, Jose Eduardo Rosa da; Conti, Thadeu das Neves; Yamaguchi, Mitsuo [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil)], e-mail: douglasborgesdomingos@yahoo.com.br

    2009-07-01

    Neutronic, thermal-hydraulics and accident analysis calculations were developed to estimate the safety of an irradiation device placed in the IEA-R1 reactor core. The irradiation device will be used to receive miniplates of U{sub 3}O{sub 8}-Al e U{sub 3}Si{sub 2}-Al dispersion fuels, LEU type (19.9% of {sup 235}U), with uranium densities of, respectively, 3.0 gU/cm{sup 3} and 4.8gU/cm{sup 3}. The fuel miniplates will be irradiated to nominal {sup 235}U burnup levels of 50% and 80%, in order to qualify the above high-density dispersion fuels to be used in the Brazilian Multipurpose Reactor, now in the conception phase. For the neutronic calculation, the computer code CITATION was utilized. The computer code FLOW was used to calculate the coolant flow rate in the irradiation device, allowing the determination of the fuel miniplate temperatures with the computer model MTRCR-IEA-R1. A postulated Loss of Coolant Accident (LOCA) was analyzed with the computer codes LOSS and TEMPLOCA, allowing the calculation of the fuel miniplate temperatures after the reactor pool draining. The calculations showed that the irradiation of the fuel miniplates will happen without any adverse consequence in the IEA-R1 reactor. (author)

  18. Development of the user Interface of digital simulation system of the operational parameters of the TRIGA IPR-R1 Nuclear Research Reactor; Desenvolvimento da interface para usuário do sistema digital de simulação dos parâmetros operacionais do reator nuclear de pesquisa Triga IPR-R1

    Energy Technology Data Exchange (ETDEWEB)

    Felippe, Adriano de A.M., E-mail: adrianoamfelippe@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Lage, Aldo M.F.; Mesquita, Amir Z., E-mail: aldo@cdtn.br, E-mail: amir@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-07-01

    The development of simulation systems has been increasingly improved to ensure security and reliability to the systems being associated. Computational tools, simulation systems and programming languages increasingly allow the diversification of control systems. With increasing concern about monitoring the key parameters involved in chain reactions inside a nuclear reactor, new technologies are being developed to ensure operations safety. This paper deals with a practical application of a work that is being developed in the Center for the Development of Nuclear Technology - CDTN, which intends to simulate the operation of the TRIGA-IPR-R1 nuclear research reactor using the LabVIEW® software, evaluating the evolution of the neutron flux and other related events. In this paper, the visual interface of the reactor control table, developed through virtual instruments that allow, in a vast repertoire of tools, replicating the panels of the control table in modern screens that can be operated by a user of an analogous form, but still more practical and complete. Since the innovations developed for research reactors can be replicated in power reactors, and because of their lower operating and maintenance costs, projects in this area allow the development of several technologies.

  19. Proposal of a synchro panel meter instrument to replace the obsolete Synchro/Resolver reading device used as position indicator of safety rods assembly of the Brazilian IEA-R1 Nuclear Research Reactor

    International Nuclear Information System (INIS)

    Toledo, Fabio de; Brancaccio, Franco; Cardenas, Jose Patricio N.

    2015-01-01

    IPEN (Instituto de Pesquisas Energeticas e Nucleares) was founded in 1956 (as Atomic Energy Institute - IEA) as a facility complex, for the research, development and application, in the nuclear technology field. The institute is recognized as a national leader in nuclear research and development (R and D), including the areas of reactor operation, radiopharmaceuticals, industrial and laboratory applications, materials science and laser technologies and applications. IPEN's main facility is the IEA-R1, nuclear research reactor (NRR), today, the only one in Brazil with a power level suitable for applications in physics, chemistry, biology and engineering. Some radioisotopes are also produced in IEA-R1, for medical and other applications. A common problem faced in the IEA-R1 maintenance is instrumentation obsolescence; spare parts are no more available, because of discontinued production, and an updating program is mandatory, aiming at modernization of old-aged I and C systems. In the presented context, an electronic system is here proposed, as a replacement for the reactor safety (shim) rods assembly position indicator, based on an open-source physical computing platform called Arduino, which includes a simple microcontroller board and a software-code development environment. A mathematical algorithm for the synchro-motor signal processing was developed, and the obtained resolution was better than 1.5%. (author)

  20. Proposal of a synchro panel meter instrument to replace the obsolete Synchro/Resolver reading device used as position indicator of safety rods assembly of the Brazilian IEA-R1 Nuclear Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Toledo, Fabio de; Brancaccio, Franco; Cardenas, Jose Patricio N., E-mail: fatoledo@ipen.br, E-mail: fbrancac@ipen.br, E-mail: ahiru@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    IPEN (Instituto de Pesquisas Energeticas e Nucleares) was founded in 1956 (as Atomic Energy Institute - IEA) as a facility complex, for the research, development and application, in the nuclear technology field. The institute is recognized as a national leader in nuclear research and development (R and D), including the areas of reactor operation, radiopharmaceuticals, industrial and laboratory applications, materials science and laser technologies and applications. IPEN's main facility is the IEA-R1, nuclear research reactor (NRR), today, the only one in Brazil with a power level suitable for applications in physics, chemistry, biology and engineering. Some radioisotopes are also produced in IEA-R1, for medical and other applications. A common problem faced in the IEA-R1 maintenance is instrumentation obsolescence; spare parts are no more available, because of discontinued production, and an updating program is mandatory, aiming at modernization of old-aged I and C systems. In the presented context, an electronic system is here proposed, as a replacement for the reactor safety (shim) rods assembly position indicator, based on an open-source physical computing platform called Arduino, which includes a simple microcontroller board and a software-code development environment. A mathematical algorithm for the synchro-motor signal processing was developed, and the obtained resolution was better than 1.5%. (author)

  1. Application of non-destructive methods for qualification of the U3O8-Al and U3Si2-Al dispersion fuels in the IEA-R1 Reactor

    International Nuclear Information System (INIS)

    Silva, Jose Eduardo Rosa da

    2011-01-01

    IPEN/CNEN-SP manufactures fuels to be used in its nuclear research reactor - the IEA-R1. To qualify those fuels, it is necessary to check if they have a good performance under irradiation. As Brazil doesn't have nuclear research reactors with high neutron fluxes, or suitable hot cells for carrying out post-irradiation examination of nuclear fuels, IPEN/CNEN-SP has conducted a fuel qualification program based on the use of uranium compounds, internationally tested and qualified to be used in research reactors, and has gotten experience in the technological development stages for the manufacturing of fuel plates, irradiation and non-destructive post-irradiation testing. Fuel elements containing low volume fractions of fuel in the dispersion were manufactured and irradiated successfully directly in the core of the IEA-R1. However, there are plans to increase the uranium density of these fuels. The objective of this thesis work was to study and to propose a set of non-destructive methods to qualify the dispersions fuels U 3 O 8 -Al e U 3 Si 2 -Al with high uranium density produced at IPEN/CNEN-SP. For that, the irradiation resources in the IEA-R1, and the application of non-destructive methods in the reactor pool available in the Institution were considered. The proposal is to specify, manufacture and irradiate fuel mini plates in IEA-R1 at the maximum densities, qualified internationally, and to monitor their general conditions during the period of irradiation, using non-destructive methods in the reactor pool. In addition to the non-destructive visual inspection and sipping methods, already used at the Institution, the infrastructure for dimensional sub-aquatic testing to evaluate the swelling of irradiated fuel mini plates was completed. The analyses of the results will provide means to assess and decide whether or not to continue with the irradiation of mini plates, until the desired burnup for the irradiation tests at IEA-R1 are reached. (author)

  2. Remote level radiation monitoring system for the brazilian IEA-R1 nuclear research reactor for routine radiation protection procedures and as a support tool in case of radiological emergency

    International Nuclear Information System (INIS)

    Cardenas, Jose P.N.; Romero Filho, Christovam R.; Madi Filho, Tufic

    2008-01-01

    Nuclear facilities must monitoring radiation levels to establish procedures for radiological protection staff involving workers and the public. The Instituto de Pesquisas Energeticas e Nucleares - IPEN has 5 important plants and in case of accident in one of them, the Institute keeps operational an Emergency Response Plan (ERP). This document (ERP) is designed to coordinate all procedures to assure safe and secure conditions for workers, environment and the public. One of this plants is the IEA-R1 reactor, it is the oldest nuclear research reactor (pool type) in Latin America, reached it first criticality in September of 1957. The reactor is used 60 hours/week with continuous operation and with nominal power of 3.5 MW, with technical conditions to operate at 5 MW thermal power. This reactor has a Radiological Emergency Plan that establishes the implementation of rules for workers and people living at the exclusion area in the case of an emergency situation. This paper aims to describe the implementation of a computational system developed for remote radiation monitoring, in a continuous schedule of IEA-R1 nuclear research reactor containment building. Results of this action can be used as a support mean in a radiological emergency. All necessary modules for radiation detection, signals conditioners and processing, data acquisition board, software development and computer specifications are described. The data acquisition system operating in the reactor shows readings concerned to radiation environment such as activity, doses and concentration in real time and displays a periodical data bank (Data Base) of this features allowing through the surveillance of the operation records anytime, leading to studies and analysis of radiation levels. Results of this data acquisition are shown by means of computer graphics screens developed for windows environment using Visual Basic software. (author)

  3. Theoretical analysis of the temperature changes and resultant loss of fuel integrity in the IEA-R1 research reactor fuel elements following a loss of coalant accident

    International Nuclear Information System (INIS)

    Garone, J.G.M.

    1983-01-01

    The IEA-R1 core following a loss of coolant accident (LOCA) is analysed. THe AIRLOCA code was used to calculate fuel temperatures, heat generation due to fission product decay and convective and radiative heat transfer from the fuel elements to the surrounding air both during and following the loss of coolant. The influence of certain critical parameters, such as log time, specific power was studied in detail. Representative results are presented and suggestions made to ensure that fuel integrity is maintained following a LOCA. (Author) [pt

  4. Uranium hexafluoride reconversion used for dispersion fuel elements fabrication for IEAR-1/SP reactor; Reconversao de hexafluoreto de uranio para a fabricacao de combustiveis na forma de dispersoes para o reator IEA-R1/SP

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, E.F. Urano de; Lainetti, P.E.; Gomes, R.P. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    1996-07-01

    In this paper are described the main chemical process employed in the Chemical Processes Division of the Fuel Technology Department - IPEN for conversion of enriched UF{sub 6} in ammonium diuranate - DUA and uranium tetrafluoride - UF{sub 4}. These activities have assured the continuity of fuel elements production at IPEN since 1984. The uranium recovery from scraps of the fuel elements production and the purification processes are also described. Those compounds are important intermediate products in the fabrication routine and in development dispersed fuel elements with higher uranium loading for IEA{sub R}1 research reactor power increase program. (author)

  5. Development of an artificial neural network for monitoring and diagnosis of sensor fault and detection in the IEA-R1 research reactor at IPEN; Utilizacao de redes neurais artificiais na monitoracao e deteccao de falhas em sensores do reator IEA-R1

    Energy Technology Data Exchange (ETDEWEB)

    Bueno, Elaine Inacio

    2006-07-01

    The increasing demand on quality in production processes has encouraged the development of several studies on Monitoring and Diagnosis Systems in industrial plant, where the interruption of the production due to some unexpected change can bring risk to the operator's security besides provoking economic losses, increasing the costs to repair some damaged equipment. Because of these two points, the economic losses and the operator's security, it becomes necessary to implement Monitoring and Diagnosis Systems. In this work, a Monitoring and Diagnosis Systems was developed based on the Artificial Neural Networks methodology. This methodology was applied to the IEA-R1 research reactor at IPEN. The development of this system was divided in three stages: the first was dedicated to monitoring, the second to the detection and the third to diagnosis of failures. In the first stage, several Artificial Neural Networks were trained to monitor the temperature variables, nuclear power and dose rate. Two databases were used: one with data generated by a theoretical model and another one with data to a typical week of operation of the IEA-R1 reactor. In the second stage, the neural networks used to monitor the variables was tested with a fault database. The faults were inserted artificially in the sensors signals. As the value of the maximum calibration error for special thermocouples is {+-}0,5 deg C, it had been inserted faults of {+-} 10 C in the sensors for the reading of the variables T3 and T4. In the third stage a Fuzzy System was developed to carry out the faults diagnosis, where were considered three conditions: a normal condition, a fault of {sub 1}0 C , and a fault of + 10 C . This system will indicate which thermocouple is faulty. (author)

  6. First results of U3Si2 production and its relevance in the power scale-up of IPEN research reactor IEA-R1m

    International Nuclear Information System (INIS)

    Saliba-Silva, A.M.; Souza, J.A.B.; Frajndlich, E.U.C.; Durazzo, M.; Perrotta, J.A.

    1997-01-01

    The own supply of LEU U 3 Si 2 is crucial for IPEN, since the whole scale-up of IPEN MTR IEA-Rlm reactor will rely on it. The Brazilian request for radioisotopes production is fully linked with the already made power scale-up from 2 to 5 MW for this reactor. IPEN now depends on fuel element material upgrading from U 3 O 8 towards LEU U 3 Si 2 . The fuel plate productive technology from the powdered material is already well established, only needing simple making of minor adjustments, but to reach the stage of producing U 3 Si 2 we need a fully settled chemical pilot plant in order to reach a LEU UF 4 productive routine. Complementing this process, it was also needed to scale down the previous practice of uranium magnesiothermic reduction to around a sub-critical safe uranium mass of approximately 3000g. To complete the metallurgical processing, it is being developed the production of U 3 Si 2 in a vacuum induction furnace. Some experiments to get this intermetallic, using natural uranium, have already been carried out in order to build up a general idea of the future process of LEU U 3 Si 2 . These experiments are described in this paper and also some of the initial characterization results, such as the qualification pattern of the ingot. It is also discussed some new features of inhomogeneity of solidified phases that may be deleterious to future production routine. (author)

  7. Estimative of core damage frequency in IPEN'S IEA-R1 research reactor due to the initiating event of loss of coolant caused by large rupture in the pipe of the primary circuit

    International Nuclear Information System (INIS)

    Hirata, Daniel Massami; Sabundjian, Gaiane; Cabral, Eduardo Lobo Lustosa

    2009-01-01

    The National Commission of Nuclear Energy (CNEN), which is the Brazilian nuclear regulatory commission, imposes safety and licensing standards in order to ensure that the nuclear power plants operate in a safe way. For licensing a nuclear reactor one of the demands of CNEN is the simulation of some accidents and thermalhydraulic transients considered as design base to verify the integrity of the plant when submitted to adverse conditions. The accidents that must be simulated are those that present large probability to occur or those that can cause more serious consequences. According to the FSAR (Final Safety Analysis Report) the initiating event that can cause the largest damage in the core, of the IEA-R1 research reactor at IPEN-CNEN/SP, is the LOCA (Loss of Coolant Accident). The objective of this paper is estimate the frequency of the IEA-R1 core damage, caused by this initiating event. In this paper we analyze the accident evolution and performance of the systems which should mitigate this event: the Emergency Coolant Core System (ECCS) and the isolated pool system. They will be analyzed by means of the event tree. In this work the reliability of these systems are also quantified using the fault tree. (author)

  8. Utilization of radioanalytical methods for the determination of isotopes of U, Pu and Am in activated charcoal from IEA-R1 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Geraldo, Bianca; Marumo, Julio T., E-mail: bgeraldo@ipen.br, E-mail: jtmarumo@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Taddei, Maria Helena T., E-mail: mhtaddei@cnen.gov.br [Laboratorio de Pocos de Caldas (LAPOC/CNEN-MG), Pocos de Caldas, MG (Brazil)

    2013-07-01

    Activated charcoal is a radioactive waste arising from the water purification system of the nuclear research reactor. The management of this waste includes its characterization in order to identify and quantify the existing radionuclides, including those known as 'difficult-to-measure radionuclides' (RDM). The analysis of these RDM usually involves complex radiochemical costly and time consuming procedures for the purification and separation of them. The objective of this work was to define a methodology of sequential analysis of isotopes of U, Pu and Am, present in activated charcoal, evaluating chemical recovery, analysis time, quantity of radioactive waste generated and cost. Ion exchange and the chromatographic extraction methodologies were compared. Both methods showed high chemical recoveries, ranged from 74 and 100% for U, 76 and 100% for Pu and 87 and 100% for Am, demonstrating that these methods provide accurate and reliable results. However, chromatographic extraction method is more suitable for the determination of the radionuclides because it generates the smaller volume of waste and is more cost-effectively. (author)

  9. Utilization of radioanalytical methods for the determination of isotopes of U, Pu and Am in activated charcoal from IEA-R1 reactor

    International Nuclear Information System (INIS)

    Geraldo, Bianca; Marumo, Julio T.; Taddei, Maria Helena T.

    2013-01-01

    Activated charcoal is a radioactive waste arising from the water purification system of the nuclear research reactor. The management of this waste includes its characterization in order to identify and quantify the existing radionuclides, including those known as 'difficult-to-measure radionuclides' (RDM). The analysis of these RDM usually involves complex radiochemical costly and time consuming procedures for the purification and separation of them. The objective of this work was to define a methodology of sequential analysis of isotopes of U, Pu and Am, present in activated charcoal, evaluating chemical recovery, analysis time, quantity of radioactive waste generated and cost. Ion exchange and the chromatographic extraction methodologies were compared. Both methods showed high chemical recoveries, ranged from 74 and 100% for U, 76 and 100% for Pu and 87 and 100% for Am, demonstrating that these methods provide accurate and reliable results. However, chromatographic extraction method is more suitable for the determination of the radionuclides because it generates the smaller volume of waste and is more cost-effectively. (author)

  10. Determination of scaling factors to estimate the radionuclide inventory in waste with low and intermediate-level activity from the IEA-R1 reactor; Determinacao de fatores de escala para estimativa do inventario de radionuclideos em rejeitos de media e baixa atividades do reator IEA-R1

    Energy Technology Data Exchange (ETDEWEB)

    Taddei, Maria Helena Tirollo

    2013-07-01

    Regulations regarding transfer and final disposal of radioactive waste require that the inventory of radionuclides for each container enclosing such waste must be estimated and declared. The regulatory limits are established as a function of the annual radiation doses that members of the public could be exposed to from the radioactive waste repository, which mainly depend on the activity concentration of radionuclides, given in Bq/g, found in each waste container. Most of the radionuclides that emit gamma-rays can have their activity concentrations determined straightforwardly by measurements carried out externally to the containers. However, radionuclides that emit exclusively alpha or beta particles, as well as gamma-rays or X-rays with low energy and low absolute emission intensity, or whose activity is very low among the radioactive waste, are generically designated as Difficult to Measure Nuclides (DTMs). The activity concentrations of these DTMs are determined by means of complex radiochemical procedures that involve isolating the chemical species being studied from the interference in the waste matrix. Moreover, samples must be collected from each container in order to perform the analyses inherent to the radiochemical procedures, which exposes operators to high levels of radiation and is very costly because of the large number of radioactive waste containers that need to be characterized at a nuclear facility. An alternative methodology to approach this problem consists in obtaining empirical correlations between some radionuclides that can be measured directly – such as {sup 60}Co and {sup 137}Cs, therefore designated as Key Nuclides (KNs) – and the DTMs. This methodology, denominated Scaling Factor, was applied in the scope of the present work in order to obtain Scaling Factors or Correlation Functions for the most important radioactive wastes with low and intermediate-activity level from the IEA-R1 nuclear research reactor. (author)

  11. Survey of nuclear parameters from the TRIGA Mark I IPR R1 Brazilian reactor with concentric configuration aiming the application of K{sub 0} neutron activation technique; Levantamento de parametros nucleares do reator TRIGA Mark I IPR R1 com configuracao concentrica visando a aplicacao da tecnica de ativacao neutronica K{sub 0}

    Energy Technology Data Exchange (ETDEWEB)

    Franco, Milton Batista

    2006-07-01

    This research intended to determine the nuclear parameters a, f, spectral index and neutron temperature in several irradiations positions of the TRIGA Mark 1 IPR-R1 reactor, for use on the parametric method K{sub 0} in the CDTN. K{sub 0} is a monostandard method of neutron activation analysis. It is, on the whole, experimentally simple, flexible and an important tool for accurate and convenient standardization in instrumental multi-element analysis. At the time the parameters were determined at the rotatory rack, lower layer and in the central thimble: alpha was calculated applying the three bare monitor method using {sup 197}Au, {sup 94}Zr and {sup 96}Zr; f determination was done according to the bare bi-isotopic method; neutron temperature was calculated through the direct method using {sup 176}Lu, {sup 94}Zr, {sup 96}Zr and {sup 197}Au and the Westcott's g(Tn) function for the {sup 176}Lu was calculated and the result was interpolated in the Grintakis and Kim (1975) Table, determining the neutron temperature. The procedure to check the parameters consisted in using standard solutions of Au (metal foil, NBS), Lu (LuO{sub 2}, Johnson Mattey Company - JMC) and Zr (ZrO{sub 2} and metal foil, Johnson Mattey Company 99,99% and Zry - 4: 98,14% of Zr, National Bureau of Standard- NBS). Several certified reference materials and two samples of intercomparisons (samples of sediment of the IAEA/ARCAL XXVI project) have been analysed by means of k{sub 0}- INAA in order to verify the efficiency of the method and the quality of the parameters. The certified reference materials were: GXR-2, GXR-5 and GXR-6 of the United States Geological Survey (USGS) and Soil-5, Soil-7 and SL-1 of the International Atomic Energy Agency (IAEA). (author)

  12. Neutronic and thermal-hydraulic analysis of devices for irradiation of LEU targets type of UALx-Al and U-Ni to production of 99Mo in reactor IEA-R1 and RMB

    International Nuclear Information System (INIS)

    Domingos, Douglas Borges

    2014-01-01

    In this work neutronic and thermal-hydraulic analyses were made to compare three types of targets (UAl 2 -Al, U-Ni cylindrical and U-Ni plate) used for the production of 99 Mo by fission of 235 U. Some experiments were conducted to validate the neutronic and thermal-hydraulics methodologies used in this work. For the neutronic calculations the computational programs NJOY99.0, AMPX-II and HAMMERTECHNION were used to generate the cross sections. SCALE 6.0 and CITATION computational programs were used for three-dimensional calculations of the reactor cores, fuel burning and the production of 99 Mo. The computational programs MTRCR-IEAR1 and ANSYS CFX were used to calculate the thermal and hydraulic parameters of the irradiation devices and for comparing them to limits and design criteria. First were performed neutronic and thermal-hydraulic analyzes for the reactor IEA-R1 with the targets of UAl 2 -Al (10 mini plates). Analyses have shown that the total activity obtained for 99 Mo on the mini plates does not meet the demand of Brazilian hospitals (450 Ci/week) and that no limit of thermo-hydraulic design is overtaken. Next, the same calculations were performed for the three target types in Multipurpose Brazilian Reactor (MBR). The neutronic analyzes demonstrated that the three targets meet the demand of Brazilian hospitals. The thermal hydraulic analysis shows that a minimum speed of 7 m/s for the target UAl 2 -Al, 8 m/s for the cylindrical target U-Ni and 9 m/s for the target U-Ni plate will be necessary in the irradiation device to not exceed the design limits. Were performed experiments using a test bench for validate the methodologies for the thermal-hydraulic calculation. The experiments performed to validate the neutronic calculations were made in the reactor IPEN/MB-01. All experiments were simulated with the methodologies described above and the results compared. The simulations results showed good agreement with experimental results. (author)

  13. Neutronic and thermal-hydraulic analysis of devices for irradiation of LEU targets type of UAL{sub x}-Al and U-Ni to production of {sup 99}Mo in reactor IEA-R1 and RMB; Analises neutronicas e termo-hidraulica de dispositivos para irradiacao de alvos tipo LEU de UAL{sub x}-Al e U-Ni para producao de {sup 99}Mo nos reatores IEA-R1 e RMB

    Energy Technology Data Exchange (ETDEWEB)

    Domingos, Douglas Borges

    2014-07-01

    In this work neutronic and thermal-hydraulic analyses were made to compare three types of targets (UAl{sub 2}-Al, U-Ni cylindrical and U-Ni plate) used for the production of {sup 99}Mo by fission of {sup 235}U. Some experiments were conducted to validate the neutronic and thermal-hydraulics methodologies used in this work. For the neutronic calculations the computational programs NJOY99.0, AMPX-II and HAMMERTECHNION were used to generate the cross sections. SCALE 6.0 and CITATION computational programs were used for three-dimensional calculations of the reactor cores, fuel burning and the production of {sup 99}Mo. The computational programs MTRCR-IEAR1 and ANSYS CFX were used to calculate the thermal and hydraulic parameters of the irradiation devices and for comparing them to limits and design criteria. First were performed neutronic and thermal-hydraulic analyzes for the reactor IEA-R1 with the targets of UAl{sub 2}-Al (10 mini plates). Analyses have shown that the total activity obtained for {sup 99}Mo on the mini plates does not meet the demand of Brazilian hospitals (450 Ci/week) and that no limit of thermo-hydraulic design is overtaken. Next, the same calculations were performed for the three target types in Multipurpose Brazilian Reactor (MBR). The neutronic analyzes demonstrated that the three targets meet the demand of Brazilian hospitals. The thermal hydraulic analysis shows that a minimum speed of 7 m/s for the target UAl{sub 2}-Al, 8 m/s for the cylindrical target U-Ni and 9 m/s for the target U-Ni plate will be necessary in the irradiation device to not exceed the design limits. Were performed experiments using a test bench for validate the methodologies for the thermal-hydraulic calculation. The experiments performed to validate the neutronic calculations were made in the reactor IPEN/MB-01. All experiments were simulated with the methodologies described above and the results compared. The simulations results showed good agreement with experimental

  14. Neutronic and thermal-hydraulic analysis of a device for irradiation of LEU UAl{sub x}-Al targets for {sup 99}Mo production in the IEA-R1 reactor; Analises neutronica e termo-hidraulica de um dispositivo para irradiacao de alvos tipo LEU de UAl{sub x}-Al para producao de {sup 99}MO no reator IEA-R1

    Energy Technology Data Exchange (ETDEWEB)

    Nishiyama, Pedro Julio Batista de Oliveira

    2012-07-01

    Technetium-99m ({sup 99m}Tc), the product of radioactive decay of molybdenum-99 ( Mo), is one of the most widely used radioisotope in nuclear medicine, covering approximately 80% of all radiodiagnosis procedures in the world. Nowadays, Brazil requires an amount of about 450 Ci of {sup 99}Mo per week. Due to the crisis and the shortage of {sup 99}Mo supply chain that has been observed on the world since 2008, IPEN/CNEN-SP decided to develop a project to produce {sup 99}Mo through fission of uranium-235. The objective of this dissertation was the development of neutronic and thermal-hydraulic calculations to evaluate the operational safety of a device for {sup 99}Mo production to be irradiated in the IEA-Rl reactor core at 5 MW. In this device will be placed ten targets of UAl{sub x}-Al dispersion fuel with low enriched uranium (LEU) and density of 2.889 gU/cm{sup 3}. For the neutronic calculations were utilized the computer codes HAMMER-TECHNION and CITATION and the maximum temperatures reached in the targets were calculated with the code MTRCR-IEA-R1. The analysis demonstrated that the device irradiation will occur without adverse consequences to the operation of the reactor. The total amount of {sup 99}Mo was calculated with the program SCALE and considering that the time needed for the chemical processing and recovering of the {sup 99}Mo will be five days after the irradiation, we have that the {sup 99}Mo activity available for distribution will be 176 Ci for 3 days of irradiation, 236 Ci for 5 days of irradiation and 272 Ci for 7 days of targets irradiation. (author)'.

  15. Methodology to monitor and diagnostic vibrations of the motor-pumps used in the primary cooling system of IEAR-1 nuclear research reactor; Metodologia para monitoracao e diagnostico de vibracao das bombas moto-operadas do circuito primario de refrigeracao do Reator IEA-R1

    Energy Technology Data Exchange (ETDEWEB)

    Benevenuti, Erion de Lima

    2004-07-01

    The objectives of this study are to establish a strategy to monitor and diagnose vibrations of the motor pumps used in the primary reactor cooling system of the IEA-R1 nuclear research reactor, to verify the possibility of using the existing installed monitoring vibration system and to implement such strategy in a continuous way. Four types of mechanical problems were considered: unbalancing, misalignment, gaps and faults in bearings. An adequate set of analysis tools, well established by the industry, was selected. These are: global measurements of vibration, velocity spectrum and acceleration envelope spectrum. Three sources of data and information were used; the data measured from the primary pumps, experimental results obtained with a Spectra Quest machine used to simulate mechanical defects and data from the literature. The results show that, for the specific case of the motor-pumps of IEA-R1 nuclear research reactor, although the technique using the envelope of acceleration, which is not available in the current system used to monitor the vibration of the motor pumps, is the one with best performance, the other techniques available in the system are sufficient to monitor the four types of mechanical problems mentioned. The proposed strategy is shown and detailed in this work. (author)

  16. Le projet de recherche: définition, conduite et réalisation

    OpenAIRE

    Stockinger , Peter

    2013-01-01

    Master; Ce support de séminaire développe brièvement les quatre points suivants: 1) Définition d’un projet de recherche – présentation générale et recommandations. 2) La conduite d’un projet de recherche – présentation générale et recommandations. 3) La réalisation d’un projet de recherche sous forme d’un mémoire - présentation générale et recommandations. 4) Des ressources pour conduire un projet de recherche : ressources enligne et références bibliographiques.

  17. Neutron flux determination at the IPR-R1 Triga Mark I neutron beam extractor

    International Nuclear Information System (INIS)

    Zangirolami, Dante Marco; Maretti Junior, Fausto; Ferreira, Andrea Vidal

    2009-01-01

    The IPR-R1 Triga Mark I Reactor located at the CDTN/CNEN, Belo Horizonte, Brazil, has been operating since November of 1960. In this work, measurements of thermal and epithermal neutron flux along the IPR-R1 neutron beam extractor were performed by neutron activation of reference materials using the two foils method. The obtained results were compared with results from two previous works: an experimental measurement done in a previous reactor core configuration and a numerical work made by Monte Carlo simulation using the actual reactor core configuration. The main purpose of this work is to update the measured data to the actual reactor core configuration. (author)

  18. Neutron radiography on the research reactor IEA-R1

    International Nuclear Information System (INIS)

    Fuga, R.

    1984-01-01

    The neutron radiography device is composed of a conical neutron collimator, having a 1/250 collimation ratio, an object chamber and an irradiation cassete. Each component on the system is described and some representative results are presented. Selected examples of the potentialities of this technique are given. (Author) [pt

  19. Analysis of kyoto university reactor physics critical experiments using NCNSRC calculation methodology

    International Nuclear Information System (INIS)

    Amin, E.; Hathout, A.M.; Shouman, S.

    1997-01-01

    The kyoto university reactor physics experiments on the university critical assembly is used to benchmark validate the NCNSRC calculations methodology. This methodology has two lines, diffusion and Monte Carlo. The diffusion line includes the codes WIMSD4 for cell calculations and the two dimensional diffusion code DIXY2 for core calculations. The transport line uses the MULTIKENO-Code vax Version. Analysis is performed for the criticality, and the temperature coefficients of reactivity (TCR) for the light water moderated and reflected cores, of the different cores utilized in the experiments. The results of both Eigen value and TCR approximately reproduced the experimental and theoretical Kyoto results. However, some conclusions are drawn about the adequacy of the standard wimsd4 library. This paper is an extension of the NCNSRC efforts to assess and validate computer tools and methods for both Et-R R-1 and Et-MMpr-2 research reactors. 7 figs., 1 tab

  20. IEA-R1 renewed primary coolant piping system stress analysis

    International Nuclear Information System (INIS)

    Fainer, Gerson; Faloppa, Altair A.; Oliveira, Carlos A. de; Mattar Neto, Miguel

    2015-01-01

    A partial replacement of the IEA-R1 piping system was conducted in 2014. The aim of this work is to perform the stress analysis of the renewed primary piping system of the IEA-R1, taking into account the as built conditions and the pipe modifications. The nuclear research reactor IEA-R1 is a pool type reactor designed by Babcox-Willcox, which is operated by IPEN since 1957. The primary coolant system is responsible for removing the residual heat of the Reactor core. As a part of the life management, a regular inspection detected some degradation in the primary piping system. In consequence, part of the piping system was replaced. The partial renewing of the primary piping system did not imply in major piping layout modifications. However, the stress condition of the piping systems had to be reanalyzed. The structural stress analysis of the primary piping systems is now presented and the final results are discussed. (author)

  1. Reactor

    International Nuclear Information System (INIS)

    Toyama, Masahiro; Kasai, Shigeo.

    1978-01-01

    Purpose: To provide a lmfbr type reactor wherein effusion of coolants through a loop contact portion is reduced even when fuel assemblies float up, and misloading of reactor core constituting elements is prevented thereby improving the reactor safety. Constitution: The reactor core constituents are secured in the reactor by utilizing the differential pressure between the high-pressure cooling chamber and low-pressure cooling chamber. A resistance port is formed at the upper part of a connecting pipe, and which is connect the low-pressure cooling chamber and the lower surface of the reactor core constituent. This resistance part is formed such that the internal sectional area of the connecting pipe is made larger stepwise toward the upper part, and the cylinder is formed larger so that it profiles the inner surface of the connecting pipe. (Aizawa, K.)

  2. Reactor

    International Nuclear Information System (INIS)

    Ikeda, Masaomi; Kashimura, Kazuo; Inoue, Kazuyuki; Nishioka, Kazuya.

    1979-01-01

    Purpose: To facilitate the construction of a reactor containment building, whereby the inspections of the outer wall of a reactor container after the completion of the construction of the reactor building can be easily carried out. Constitution: In a reactor accommodated in a container encircled by a building wall, a space is provided between the container and the building wall encircling the container, and a metal wall is provided in the space so that it is fitted in the building wall in an attachable or detatchable manner. (Aizawa, K.)

  3. Performance and management of IPR-R1 fuel elements

    International Nuclear Information System (INIS)

    Stasiulevicius, R.; Maretti Junior, F.

    1983-01-01

    The performance of fuel elements during the 23 years of the reactor operation, is presented aiming to introduce improvements in the fuel load distribution and consequent increase of the reactivity. A computer code CORE was developed aiming to calculate the individual burnup of the fuel elements and the value of the reactivity for several core configurations, establishing a routine to control the nuclear material in the IPR-R1. The values calculated were compared with the experimental results. Some alternatives to augment the reactivity of the present core are presented foreseeing the fuel load availability for operation with 100Km and, for angmenting the power reaction in a next stage. (E.G.) [pt

  4. Study of IPR-R1 dynamics by reactivity random excitations

    International Nuclear Information System (INIS)

    Roedel, G.

    1983-01-01

    To demonstrate the viability of the utilization of analitical techniques of neutronic noise, a dynamic model for IPR-R1 reactor from CDTN was developed. This model allows reactivity feedback due to variations of temperature in fuel and coolant [pt

  5. Reactors

    DEFF Research Database (Denmark)

    Shah, Vivek; Vaz Salles, Marcos António

    2018-01-01

    The requirements for OLTP database systems are becoming ever more demanding. Domains such as finance and computer games increasingly mandate that developers be able to encode complex application logic and control transaction latencies in in-memory databases. At the same time, infrastructure...... engineers in these domains need to experiment with and deploy OLTP database architectures that ensure application scalability and maximize resource utilization in modern machines. In this paper, we propose a relational actor programming model for in-memory databases as a novel, holistic approach towards......-level function calls. In contrast to classic transactional models, however, reactors allow developers to take advantage of intra-transaction parallelism and state encapsulation in their applications to reduce latency and improve locality. Moreover, reactors enable a new degree of flexibility in database...

  6. Triga IPR-R1 neutron beam: increasing the thematic of applications in CDTN

    International Nuclear Information System (INIS)

    Sebastiao, Rita de C.O.; Rodrigues, Rogerio R.; Leal, Alexandre S.

    2007-01-01

    The neutron flux in a research reactor can be used in several applications such as the neutron activation analysis, the radioisotopes production, study of DNA and protein structures, doping of silicon and neutron radiography. The enhancement of the nuclear research reactor utilization with the introduction of new applications would be possible with the availability of a neutron beam and with the neutron energy spectra completely characterized. This work evaluates the use of TRIGA reactor of CDTN/CNEN as a source of neutron beam. The readiness of a neutron beam with appropriate intensity and energy spectrum would make possible the increasing of the thematic of applications and researches in this reactor. The main contribution to this theme is to evaluate the thermal and epithermal neutron flux in the vertical extractor of the TRIGA IPR-R1. The simulation was performed in this work using the MCNP code. (author)

  7. CFD simulation of IPR-R1 Triga subchannels fluid flow

    International Nuclear Information System (INIS)

    Silva, Vitor V.; Santos, A.; Mesquita, Amir Z.; Silva, P.S. da; Pereira, C.

    2013-01-01

    Computational fluid dynamics (CFD) codes have been extensively used in engineering problems, with increasing use in nuclear engineering. One of these computer codes is OpenFOAM. It is freely distributed with source code and offers a great flexibility in simulating particular conditions like those found in many problems in nuclear reactor analysis. The aim of this work is to simulate fluid flow and heat flux in three different configurations of subchannels of IPR-R1 TRIGA reactor using OpenFOAM. The data will be then validated against real experimental data obtained during the operation of the reactor at 100kW. This validation process is fundamental to allow the use of the software and associated model to simulate reactor's operation at different conditions, namely different power e fluid flow velocities. (author)

  8. CFD simulation of IPR-R1 Triga subchannels fluid flow

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Vitor V.; Santos, A.; Mesquita, Amir Z.; Silva, P.S. da, E-mail: vitors@cdtn.br, E-mail: aacs@cdtn.br, E-mail: amir@cdtn.br, E-mail: psblsg@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN - MG), Belo Horizonte, MG (Brazil); Pereira, C., E-mail: claubia@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear

    2013-07-01

    Computational fluid dynamics (CFD) codes have been extensively used in engineering problems, with increasing use in nuclear engineering. One of these computer codes is OpenFOAM. It is freely distributed with source code and offers a great flexibility in simulating particular conditions like those found in many problems in nuclear reactor analysis. The aim of this work is to simulate fluid flow and heat flux in three different configurations of subchannels of IPR-R1 TRIGA reactor using OpenFOAM. The data will be then validated against real experimental data obtained during the operation of the reactor at 100kW. This validation process is fundamental to allow the use of the software and associated model to simulate reactor's operation at different conditions, namely different power e fluid flow velocities. (author)

  9. Reactor

    International Nuclear Information System (INIS)

    Fujibayashi, Toru.

    1976-01-01

    Object: To provide a boiling water reactor which can enhance a quake resisting strength and flatten power distribution. Structure: At least more than four fuel bundles, in which a plurality of fuel rods are arranged in lattice fashion which upper and lower portions are supported by tie-plates, are bundled and then covered by a square channel box. The control rod is movably arranged within a space formed by adjoining channel boxes. A spacer of trapezoidal section is disposed in the central portion on the side of the channel box over substantially full length in height direction, and a neutron instrumented tube is disposed in the central portion inside the channel box. Thus, where a horizontal load is exerted due to earthquake or the like, the spacers come into contact with each other to support the channel box and prevent it from abnormal vibrations. (Furukawa, Y.)

  10. Study of the IPR-R1 dynamics by means of reactivity pseudo-aleatory excitations

    International Nuclear Information System (INIS)

    Roedel, G.

    1983-01-01

    Aiming to demonstrate the feasibility of using the reactor noise neutronic analysis tecniques a dynamic model was developed for the IPR-R1 reactor at CDTN. This model allows reactivity feedback, due to the variations of fuel and coolant temperature. The system was excited by the variations of reactivity modulated by a pseudo aleatory binary sequence and its answer was measured by means of the fluctuactions dround the stationary power. The model developed and the technique used was tested, and the values of the system parameters obtained from the adjustment of the theoretical and experimental transfer function were compared to another, obtained from independent process. (E.G.) [pt

  11. Initial mass function in R-associations CMaR1, Mon R1 and Mon R2 from radiodata

    International Nuclear Information System (INIS)

    Pyatunina, T.B.

    1985-01-01

    Results of search for compact radiosources in R-associations CMa R1 and Mon R1 carried out with the radiotelescope RATAN-600 at the 7.6-cm wavelength are given. The number of sources found in the association Mon R1 is approximately equal to the expected number of background extragalactic radiosources. In the association CMa R1 seven radiosources of small angular diameter with the flux greater than 30 mJy are found, two of which probably are background sources. A comparison of optical and radiodata on the association CMa R1 and previously published data on the association Mon R2 make it possible to estimate the initial mass function for associations under study: xi(M) infinity Msup(-2.7+-0.7) for stars with M approximately 10Msub(Sun)

  12. Structural evaluation of IEA-R1 primary system pump nozzles

    Energy Technology Data Exchange (ETDEWEB)

    Fainer, Gerson; Faloppa, Altair A.; Oliveira, Carlos A. de; Mattar Neto, Miguel, E-mail: gfainer@ipen.br, E-mail: afaloppa@ipen.br, E-mail: calberto@ipen.br, E-mail: mmattar@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2017-11-01

    The IEA-R1 pumps of the primary coolant system may be required to withstand design and operational conditions. IEA-R1 nuclear research reactor is an open pool type reactor operated by IPEN since 1957. The reactor can be operated up to 5MW heating power since it was upgraded in a modernization program conducted by IPEN. The primary coolant system is composed by the piping system, decay tank, two heat pumps and two heat exchangers. In the latest arrangement upgrade of the primary system, conducted in 2014 as part of an aging management program, a partial replacement of the coolant piping and total replacement of piping and pump supports were done. As consequence, reviewed loads in the pump nozzles were obtained demanding a new evaluation of them. The aim of this report is to present the structural evaluation of the pump nozzles, considering the new loads coming from the new piping layout, according to: API 610 code verification, Supplier loads and structural analysis applying finite element method, by using the ANSYS computer program, regarding ASME VIII Div 1 & 2 recommendations. (author)

  13. IEA-R1 primary and secondary coolant piping systems coupled stress analysis

    International Nuclear Information System (INIS)

    Fainer, Gerson; Faloppa, Altair A.; Oliveira, Carlos A.; Mattar Neto, Miguel

    2013-01-01

    The aim of this work is to perform the stress analysis of a coupled primary and secondary piping system of the IEA-R1 based on tridimensional model, taking into account the as built conditions. The nuclear research reactor IEA-R1 is a pool type reactor projected by Babcox-Willcox, which is operated by IPEN since 1957. The operation to 5 MW power limit was only possible after the conduction of life management and modernization programs in the last two decades. In these programs the components of the coolant systems, which are responsible for the water circulation into the reactor core to remove the heat generated inside it, were almost totally refurbished. The changes in the primary and secondary systems, mainly the replacement of pump and heat-exchanger, implied in piping layout modifications, and, therefore, the stress condition of the piping systems had to be reanalyzed. In this paper the structural stress assessment of the coupled primary and secondary piping systems is presented and the final results are discussed. (author)

  14. Structural evaluation of IEA-R1 primary system pump nozzles

    International Nuclear Information System (INIS)

    Fainer, Gerson; Faloppa, Altair A.; Oliveira, Carlos A. de; Mattar Neto, Miguel

    2017-01-01

    The IEA-R1 pumps of the primary coolant system may be required to withstand design and operational conditions. IEA-R1 nuclear research reactor is an open pool type reactor operated by IPEN since 1957. The reactor can be operated up to 5MW heating power since it was upgraded in a modernization program conducted by IPEN. The primary coolant system is composed by the piping system, decay tank, two heat pumps and two heat exchangers. In the latest arrangement upgrade of the primary system, conducted in 2014 as part of an aging management program, a partial replacement of the coolant piping and total replacement of piping and pump supports were done. As consequence, reviewed loads in the pump nozzles were obtained demanding a new evaluation of them. The aim of this report is to present the structural evaluation of the pump nozzles, considering the new loads coming from the new piping layout, according to: API 610 code verification, Supplier loads and structural analysis applying finite element method, by using the ANSYS computer program, regarding ASME VIII Div 1 & 2 recommendations. (author)

  15. Final report on the IAEA research contracts No. 1194/RB, 1194/R1/RB and 1194/R2/RB

    International Nuclear Information System (INIS)

    Zobor, E.; Janosy, J.S.; Szentgali, A.

    1980-09-01

    The final report summarizes the research activities made in the framework of the IAEA Research Contracts No. 1194/RB, 1194/R1/RB and 1194/R2/RB. A multilevel hierarchical control system is treated which uses weakly-coupled low dimensional subsystems under the supervision of a dynamic coordinator program. This self-organizing adaptive control system was checked by a 5 MW research reactor. As an example the paper describes the experimental computer control system of the 5 MW WWR-SM research reactor, where the reactor power and outlet temperature have been controlled on the basis of the treated control concept since 1978. (author)

  16. Oracle BAM 11gR1 Handbook

    CERN Document Server

    Wang, Pete

    2012-01-01

    "Oracle BAM 11gR1 Handbook" is a practical best practices tutorial focused entirely on Oracle Business Activity Monitoring. An intermediate-to-advanced guide, step-by-step instructions and an accompanying demo project will help SOA report developers through application development and producing dashboards and reports. If you are a developer/report developer or SOA Architect who wants to learn valuable Oracle BAM best practices for monitoring your operations in real time, then "Oracle BAM 11gR1 Handbook" is for you. Administrators will also find the book useful. You should already be comfortabl

  17. Nuclear reactors

    International Nuclear Information System (INIS)

    Yoshioka, Michiko.

    1985-01-01

    Purpose: To obtain an optimum structural arrangement of IRM having a satisfactory responsibility to the inoperable state of a nuclear reactor and capable of detecting the reactor power in an averaged manner. Constitution: As the structural arrangement of IRM, from 6 to 16 even number of IRM are bisected into equial number so as to belong two trip systems respectively, in which all of the detectors are arranged at an equal pitch along a circumference of a circle with a radius rl having the center at the position of the central control rod in one trip system, while one detector is disposed near the central control rod and other detectors are arranged substantially at an equal pitch along the circumference of a circle with a radius r2 having the center at the position for the central control rod in another trip system. Furthermore, the radius r1 and r2 are set such that r1 = 0.3 R, r2 = 0.5 R in the case where there are 6 IRM and r1 = 0.4 R and R2 = 0.8 R where there are eight IRM where R represents the radius of the reactor core. (Kawakami, Y.)

  18. In-service inspection of ET-RR-1 reactor vessels and spent fuel storage tank

    International Nuclear Information System (INIS)

    Khattab, M.; Shafy, M.; Konoplev, K.; Samodurve, YU.; Orlov, S.; Didenko, V.; Jackorev, O.

    1993-01-01

    Technical survey included in-service inspection are needed in order to investigate the structural integrity and to insure safe operation of the ET-R R-1 reactor after thirty years aging. An intensive work for the inspection of the inspection of the central tank, shield tank, horizontal channels, primary coolant circuit and spent fuel storage tank have been carried out. The inspection procedures were visual method using video camera and magnification optical as well as thickness measurements using ultrasonic gauge meter and replica for determining defect depth. Water chemical analysis of the primary cooling circuit and spent fuel storage were helpful in results explanation. The results showed that the reactor vessels have good surface conditions. The observed pitting did not affect the structural integrity. The majority of the defects were pits having maximum surface area of about 50 mm. Their depth does not exceed 2 mm. The pits depth rate penetration is of the order of 0.5% per year. Thickness measurements showed insignificant variation. Water status and its chemical properties are very important in controlling corrosion rate. 18 figs., 14 tabs

  19. Transient cases analyses of the TRIGA IPR-R1 using thermal hydraulic and neutron kinetic coupled codes

    Energy Technology Data Exchange (ETDEWEB)

    Reis, Patricia A.L.; Costa, Antonella L.; Pereira, Claubia; Veloso, Maria A.F.; Scari, Maria E., E-mail: patricialire@yahoo.com.br, E-mail: antonella@nuclear.ufmg.br, E-mail: claubia@nuclear.ufmg.br, E-mail: dora@nuclear.ufmg.br, E-mail: melizabethscari@yahoo.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Instituto Nacional de Ciencias e Tecnologia de Reatores Nucleares Inovadores (INCT/CNPq), Belo Horizonte (Brazil); Miro, Rafael; Verdu, Gumersindo, E-mail: rmiro@iqn.upv.es, E-mail: gverdu@iqn.upv.es [Universidad Politecnica de Valencia (Spain). Departamento de Ingenieria Quimica y Nuclear

    2015-07-01

    Simulations and analyses of nuclear reactors have been improved by utilization of coupled thermal-hydraulic (TH) and neutron kinetics (NK) system codes especially to simulate transients that involve strong feedback effects between NK and TH. The TH-NK coupling technique was initially developed and used to simulate the behavior of power reactors; however, several coupling methodologies are now being applied for research reactors. This work presents the coupling methodology application between RELAP5 and PARCS codes using as a model the TRIGA IPR-R1 research reactor. Analyses of steady state and transient conditions and comparisons with results from simulations using only the RELAP5 code are being presented in this paper. (author)

  20. Utilization of the IPR-R1 as a tool in the evaluation of the brazilian uranium reserves

    International Nuclear Information System (INIS)

    Stasiulevicius, R.

    1986-01-01

    The Brazilian uranium ore resources reach an amount of 301,490 metric tons of U 3 O 8 , twenty-seven times more than the known value when NUCLEBRAS was founded, at the end of 1974. In evaluating this reserve, the IPR-R1 research nuclear reactor has given a significant contribution. This reactor has been in operation since 1960 for research, technology, radionuclide production and training purposes. The available irradiation facilities allow the use of neutron-activation to determine uranium contents. Up to now, a total of 330,000 mineral sample analyses were carried out. (Author) [pt

  1. Utilization of the IPR-R1 as a tool in the evaluation of the Brazilian uranium reserves

    International Nuclear Information System (INIS)

    Stasiulevicius, R.

    1986-01-01

    The Brazilian uranium ore resources reach an amount of 301,490 metric tons of U 3 O 8 , twenty-seven times more than the known value when NUCLEBRAS was founded, at the end of 1974. In evaluating this reserve, the IPR-R1 research nuclear reactor has given a significant contribution. This reactor has been in operation since 1960 for research, technology, radionuclide production and training purposes. The evailable irradiation facilities allow the use of neutron-activation to determine uranium contents. Up to now, a total of 330,000 mineral sample analyses were carried out. (Author) [pt

  2. Neutronic parameters characterization of the TRIGA IPR-R1 using scale 6.0 (KENO VI)

    International Nuclear Information System (INIS)

    Faria, Victor; Miro, Rafael; Verdu, Gumersindo; Barrachina, Teresa; Silva, Clarysson A. Mello da; Pereira, Claubia

    2011-01-01

    KENO-VI is a Monte Carlo based transport code used to obtain the criticality of a nuclear system. A model built using this code in the SCALE6.0 software system was developed for the characterization of neutronic parameters of the IPR-R1 TRIGA research reactor. A comparison with experimental values and those calculated with a MCNP code model could be then attained with the purpose to validate this methodology. (author)

  3. Neutronic parameters characterization of the TRIGA IPR-R1 using scale 6.0 (KENO VI)

    Energy Technology Data Exchange (ETDEWEB)

    Faria, Victor; Miro, Rafael; Verdu, Gumersindo; Barrachina, Teresa [Institute for Industrial, Radiophysical and Environmental Safety (ISIRYM), Universitat Politecnica de València (Spain); Silva, Clarysson A. Mello da; Pereira, Claubia [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Dalle, Hugo Moura [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    KENO-VI is a Monte Carlo based transport code used to obtain the criticality of a nuclear system. A model built using this code in the SCALE6.0 software system was developed for the characterization of neutronic parameters of the IPR-R1 TRIGA research reactor. A comparison with experimental values and those calculated with a MCNP code model could be then attained with the purpose to validate this methodology. (author)

  4. Absorption and Flux Density Measurements in an Iron Plug in R1

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Ragnar; Braun, Josef

    1958-11-15

    Thermal, epithermal and fast neutron fluxes have been measured in a 60 cm long, 'sliced' iron plug, which has been placed in the lower iron lid of the Swedish reactor R1. Au foils, Cu foils, Mn foils, P packets, Cu wires and small Fe cylinders have been used. The gamma flux has been determined with film dosimeters. The measurements have shown that only in the first centimeters of the iron is the activation determined by the thermal flux, which decreases with a relaxation length {lambda}= (1.51 {+-} 0.02) cm. The epithermal flux is entirely predominant already after 10 cm ( {lambda} = 16 cm). The epithermal neutron flux decreases even more slowly than the fast flux ({lambda} = 6.2 cm)

  5. Absorption and Flux Density Measurements in an Iron Plug in R1

    International Nuclear Information System (INIS)

    Nilsson, Ragnar; Braun, Josef

    1958-11-01

    Thermal, epithermal and fast neutron fluxes have been measured in a 60 cm long, 'sliced' iron plug, which has been placed in the lower iron lid of the Swedish reactor R1. Au foils, Cu foils, Mn foils, P packets, Cu wires and small Fe cylinders have been used. The gamma flux has been determined with film dosimeters. The measurements have shown that only in the first centimeters of the iron is the activation determined by the thermal flux, which decreases with a relaxation length λ= (1.51 ± 0.02) cm. The epithermal flux is entirely predominant already after 10 cm ( λ = 16 cm). The epithermal neutron flux decreases even more slowly than the fast flux (λ = 6.2 cm)

  6. Flow distribution experimental study on the emergency core cooling system of the IEA-R1m - IPEN-CNEN/SP - Brazil

    International Nuclear Information System (INIS)

    Torres, Walmir Maximo; Baptista Filho, Benedito Dias; Ting, Daniel Kao Sun

    1999-01-01

    This paper presents a brief description of Emergency Core Cooling System designed by the IEA-R1m Reactor and the experimental results of flow distribution over the core. Several parameters were evaluated, such as: relative position of spray header to the reactor core; type and quantity of spray nozzles; spray nozzles position on spray header; and total spray flow. The main conclusions are presented. (author)

  7. Molecular characterization of the Jatropha curcas JcR1MYB1 gene encoding a putative R1-MYB transcription factor

    Directory of Open Access Journals (Sweden)

    Hui-Liang Li

    2014-09-01

    Full Text Available The cDNA encoding the R1-MYB transcription factor, designated as JcR1MYB1, was isolated from Jatropha curcas using rapid amplification of cDNA ends. JcR1MYB1 contains a 951 bp open reading frame that encodes 316 amino acids. The deduced JcR1MYB1 protein was predicted to possess the conserved, 56-amino acid-long DNA-binding domain, which consists of a single helix-turn-helix module and usually occurs in R1-MYBs. JcR1MYB1 is a member of the R1-MYB transcription factor subfamily. A subcellular localization study confirmed the nuclear localization of JcR1MYB1. Expression analysis showed that JcR1MYB1 transcripts accumulated in various examined tissues, with high expression levels in the root and low levels in the stem. JcR1MYB1 transcription was up-regulated by polyethylene glycol, NaCl, and cold treatments, as well as by abscisic acid, jasmonic acid, and ethylene treatment. Analysis of transgenic tobacco plants over-expressing JcR1MYB1 indicates an inportant function for this gene in salt stress.

  8. Mechanical response of shock conditioned HPNS-5 (R-1) grout

    International Nuclear Information System (INIS)

    Plannerer, H.N.

    1997-01-01

    HPNS-5 (R-1) grout is a portland cement formulated mix designed for use as a rigid containment plug in vertical boreholes at the Nevada Test Site. Coincident with field testing of this grout in 1991 and 1992 , two arums of the grout mix were collected and positioned in the by pass drift of the DISTANT ZENITH event to expose the grout to passage of a nuclear driven stress wave. The drums were later retrieved to determine the mechanical behavior of the shock conditioned grout. Sealed hollow tubes positioned within the grout-filled drums to detect ductile flow on passage of the stress wave were found partially to completely filled with HPNS-5 grout following the experiment. Static mechanical tests support the evidence for ductile flow and place the transition from brittle fracture failure to ductile behavior in the shock conditioned grout at a confining stress between ambient and 5 MPa (725 psi). Uniaxial and triaxial tests delineated a stress-strain field for interstice collapse that interposes between the mechanics of linear elastic deformation and dilatancy. Hydrostatic stress loading between 25 MPa (3.6 ksi) and 60 MPa (8.7 ksi) results in a significant change of permanent set from 1% to greater than 15% volume strain

  9. RED DRAGON FRUIT (Hylocereus costaricensis Britt. Et R. PEEL EXTRACT AS A NATURAL DYE ALTERNATIVE IN MICROSCOPIC OBSERVATION OF PLANT TISSUES: THE PRACTICAL GUIDE IN SENIOR HIGH SCHOOL

    Directory of Open Access Journals (Sweden)

    Heni Wagiyanti

    2017-11-01

    Full Text Available Prepared slide of plant tissue needs to be staining to facilitate observations under microscope. Laboratorium activities in schools usually use synthetic dyes which expensive and can be damaged the student. Therefore the exploration of alternative dyes need to be established, such as utilizing of red dragon fruit (Hylocereus castaricensis Britt. Et R.. This study aims to (1 find out the best concentration of dragon fruit peel extract for staining plant tissue prepared slide and (2 to develop the practical guide related to plant tissue observation. The qualitative research used different concentration of red dragon fruit peel extract, namely: 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100% with 3 repetitions. Data were obtained from observation photos of prepared slide. The result showed that the most contrast prepared slide was used red dragon fruit extract in 60% concentration. The result use to arrange practical guide in observation of plant tissues which is validated by material expert. The validation result showed “very good” criteria (86.01%.

  10. Method development and validation for simultaneous determination of IEA-R1 reactor’s pool water uranium and silicon content by ICP OES

    Science.gov (United States)

    Ulrich, J. C.; Guilhen, S. N.; Cotrim, M. E. B.; Pires, M. A. F.

    2018-03-01

    IPEN’s research reactor, IEA-R1, an open pool type research reactor moderated and cooled by light water. High quality water is a key factor in preventing the corrosion of the spent fuel stored in the pool. Leaching of radionuclides from the corroded fuel cladding may be prevented by an efficient water treatment and purification system. However, as a safety management policy, IPEN has adopted a water chemistry control which periodically monitors the levels of uranium (U) and silicon (Si) in the pool’s reactor, since IEA-R1 employs U3Si2-Al dispersion fuel. An analytical method was developed and validated for the determination of uranium and silicon by ICP OES. This work describes the validation process, in a context of quality assurance, including the parameters selectivity, linearity, quantification limit, precision and recovery.

  11. Microarray analysis in the archaeon Halobacterium salinarum strain R1.

    Directory of Open Access Journals (Sweden)

    Jens Twellmeyer

    Full Text Available BACKGROUND: Phototrophy of the extremely halophilic archaeon Halobacterium salinarum was explored for decades. The research was mainly focused on the expression of bacteriorhodopsin and its functional properties. In contrast, less is known about genome wide transcriptional changes and their impact on the physiological adaptation to phototrophy. The tool of choice to record transcriptional profiles is the DNA microarray technique. However, the technique is still rarely used for transcriptome analysis in archaea. METHODOLOGY/PRINCIPAL FINDINGS: We developed a whole-genome DNA microarray based on our sequence data of the Hbt. salinarum strain R1 genome. The potential of our tool is exemplified by the comparison of cells growing under aerobic and phototrophic conditions, respectively. We processed the raw fluorescence data by several stringent filtering steps and a subsequent MAANOVA analysis. The study revealed a lot of transcriptional differences between the two cell states. We found that the transcriptional changes were relatively weak, though significant. Finally, the DNA microarray data were independently verified by a real-time PCR analysis. CONCLUSION/SIGNIFICANCE: This is the first DNA microarray analysis of Hbt. salinarum cells that were actually grown under phototrophic conditions. By comparing the transcriptomics data with current knowledge we could show that our DNA microarray tool is well applicable for transcriptome analysis in the extremely halophilic archaeon Hbt. salinarum. The reliability of our tool is based on both the high-quality array of DNA probes and the stringent data handling including MAANOVA analysis. Among the regulated genes more than 50% had unknown functions. This underlines the fact that haloarchaeal phototrophy is still far away from being completely understood. Hence, the data recorded in this study will be subject to future systems biology analysis.

  12. Optimisation de tournées de véhicules dans le cadre de la logistique inverse : modélisation et résolution par des méthodes hybrides

    OpenAIRE

    Grellier , Emilie

    2008-01-01

    Vehicle routing problems in inverse logistics : modelling and solving with hybrid methods; Optimisation des tournées de véhicules dans le cadre de la logistique inverse : modélisation et résolution par des méthodes hybrides

  13. Data of evolutionary structure change: 1R1YC-2ZLWD [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1R1YC-2ZLWD 1R1Y 2ZLW C D -VLSPADKTNVKAAWGKVGAHAGEYGAEALERMFLSFPT...R VQLSGEEKAAVLALWDKVN--EEEVGGEALGRLLVVYPWTQRFFDSFGDLSNPGAVMGNPKVKAHGKKVLHSFGEGVHHLDNLKGTFAALSEL...ex> 2ZLW D 2ZLWD WDK

  14. Radio evidence for the initial stellar mass function in the R associations CMa R1, Mon R1, Mon R2

    International Nuclear Information System (INIS)

    Pyatunina, T.B.

    1985-01-01

    The R associations CMa R1 and Mon R1 have been searched for compact 7.6-cm sources with the RATAN-600 radio telescope. The Mon R1 region shows only about the expected number of background radio galaxies; in CMa R1 seven sources of small angular size with S> or =30 mJy have been found, two of them probably background objects. Comparison with optical data for CMa R1, together with previous RATAN-600 data for Mon R2, yields an initial mass function xi(M)proportionalM/sup -2.7plus-or-minus0.7/ for the rather massive (Mroughly-equal10 M/sub sun/) stars in these associations

  15. 26 CFR 1.414(r)-1 - Requirements applicable to qualified separate lines of business.

    Science.gov (United States)

    2010-04-01

    ... lines of business. 1.414(r)-1 Section 1.414(r)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT... Plans, Etc. § 1.414(r)-1 Requirements applicable to qualified separate lines of business. (a) In general. Section 414(r) prescribes the conditions under which an employer is treated as operating qualified...

  16. Evolution of doses in the IEA-R1/NRR environment and tendencies based on the current results

    International Nuclear Information System (INIS)

    Toyoda, Eduardo Yoshio; Sordi, Gian-Maria; Vaz, Antonio C.A.

    2015-01-01

    The IPEN / CNEN-SP has a Nuclear Research Reactor-NRR named IEA-R1, in operation since 1957. Until 1995 the reactor operated daily at a power of 2,0 MW. From June of that year, after a few safety modifications the reactor began operating in continuous way from Monday to Wednesday without shutdown totaling 64 hours per week, also the power was increased until 4,5MW in 2012. Because of these changes, continuous operation and increased power, workers' doses increased. In the past, several studies were conducted seeking ways to reduce the workers' doses. The purpose of this paper is to analyze the individual doses of OEI (occupationally exposed individual), considering the changes in reactor operation mode and to suggest the viable protection and safety options, in the first instance to reduce the doses in question aimed at the goal of reaching acceptable region, that is, lower or at most equal to 5 mSv / year for the International Commission on Radiological Protection(ICRP). (author)

  17. Nuclear research reactors in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Cota, Anna Paula Leite; Mesquita, Amir Zacarias, E-mail: aplc@cdtn.b, E-mail: amir@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    The rising concerns about global warming and energy security have spurred a revival of interest in nuclear energy, giving birth to a 'nuclear power renaissance' in several countries in the world. Particularly in Brazil, in the recent years, the nuclear power renaissance can be seen in the actions that comprise its nuclear program, summarily the increase of the investments in nuclear research institutes and the government target to design and build the Brazilian Multipurpose research Reactor (BMR). In the last 50 years, Brazilian research reactors have been used for training, for producing radioisotopes to meet demands in industry and nuclear medicine, for miscellaneous irradiation services and for academic research. Moreover, the research reactors are used as laboratories to develop technologies in power reactors, which are evaluated today at around 450 worldwide. In this application, those reactors become more viable in relation to power reactors by the lowest cost, by the operation at low temperatures and, furthermore, by lower demand for nuclear fuel. In Brazil, four research reactors were installed: the IEA-R1 and the MB-01 reactors, both at the Instituto de Pesquisas Energeticas Nucleares (IPEN, Sao Paulo); the Argonauta, at the Instituto de Engenharia Nuclear (IEN, Rio de Janeiro) and the IPR-R1 TRIGA reactor, at the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN, Belo Horizonte). The present paper intends to enumerate the characteristics of these reactors, their utilization and current academic research. Therefore, through this paper, we intend to collaborate on the BMR project. (author)

  18. Nuclear research reactors in Brazil

    International Nuclear Information System (INIS)

    Cota, Anna Paula Leite; Mesquita, Amir Zacarias

    2011-01-01

    The rising concerns about global warming and energy security have spurred a revival of interest in nuclear energy, giving birth to a 'nuclear power renaissance' in several countries in the world. Particularly in Brazil, in the recent years, the nuclear power renaissance can be seen in the actions that comprise its nuclear program, summarily the increase of the investments in nuclear research institutes and the government target to design and build the Brazilian Multipurpose research Reactor (BMR). In the last 50 years, Brazilian research reactors have been used for training, for producing radioisotopes to meet demands in industry and nuclear medicine, for miscellaneous irradiation services and for academic research. Moreover, the research reactors are used as laboratories to develop technologies in power reactors, which are evaluated today at around 450 worldwide. In this application, those reactors become more viable in relation to power reactors by the lowest cost, by the operation at low temperatures and, furthermore, by lower demand for nuclear fuel. In Brazil, four research reactors were installed: the IEA-R1 and the MB-01 reactors, both at the Instituto de Pesquisas Energeticas Nucleares (IPEN, Sao Paulo); the Argonauta, at the Instituto de Engenharia Nuclear (IEN, Rio de Janeiro) and the IPR-R1 TRIGA reactor, at the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN, Belo Horizonte). The present paper intends to enumerate the characteristics of these reactors, their utilization and current academic research. Therefore, through this paper, we intend to collaborate on the BMR project. (author)

  19. La temporalité de l’utopie : entre création et réaction The temporality of Utopia: between creation and reaction

    Directory of Open Access Journals (Sweden)

    Marie-Ange Cossette-Trudel

    2010-12-01

    Full Text Available La conception prédominante de l’utopie comme système clos est à l’origine même de son enfermement, tant notionnel que conceptuel. Hors du temps, sise dans un espace extérieur au réel, l’utopie ainsi axiomatisée peut difficilement être saisie comme une composante effective du présent. Outre l’acceptation généralisée de cet ou-topos (non-lieu, le manque de consensus sur sa définition fait partie de son épigraphie chronographique. Accusée tour à tour de créer une vision sociétale totalitaire, messianique ou encore technocratique, la nature de l’utopie est encore à ce jour insaisissable, et la matrice de son plan théorique reste imprécise. Pour lui trouver une définition qui enchâsse ses différentes fractions, nous devrons observer de plus près ses deux dimensions constitutives, entre création et réaction, là où l’utopie est bien plus qu’un projet de subversion ; là où les possibles cessent de coïncider avec le réel pour laisser place à l’actualisation du virtuel, de l’élan vital. À la lumière de cette nouvelle définition de l’utopie, la relecture de l’œuvre de Charles Fourier est particulièrement pertinente : l’élan à la base de son projet d’expérimentation concrète transcende le temps historique et redonne à l’utopie ses deux dimensions insécables. De l’attraction passionnée au Phalanstère, il est un des rares penseurs à avoir joué tant sur le plan immanent que transcendant de l’utopie.The predominant conception of utopia as a closed system has become its own conceptual and notional prison. Out of the reach of Time, based in a space outside reality, utopia can hardly be seen as part of the present. Aside from the generally accepted idea that utopia is a u-topos (non-place, the lack of consensus on how to define it represents its historical continuum. Accused of producing a totalitarian, Messianic or technocratic vision of society, the nature of utopia is still

  20. Benchmarking circumferential resection margin (R1) resection rate for rectal cancer in the neoadjuvant era.

    Science.gov (United States)

    Chambers, W; Collins, G; Warren, B; Cunningham, C; Mortensen, N; Lindsey, I

    2010-09-01

    Circumferential resection margin (CRM) involvement (R1) is used to audit rectal cancer surgical quality. However, when downsizing chemoradiation (dCRT) is used, CRM audits both dCRT and surgery, its use reflecting a high casemix of locally advanced tumours. We aimed to evaluate predictors of R1 and benchmark R1 rates in the dCRT era, and to assess the influence of failure of steps in the multidisciplinary team (MDT) process to CRM involvement. A retrospective analysis of prospectively collected rectal cancer data was undertaken. Patients were classified according to CRM status. Uni- and multivariate analysis was undertaken of risk factors for R1 resection. The contribution of the steps of the MDT process to CRM involvement was assessed. Two hundred and ten rectal cancers were evaluated (68% T3 or T4 on preoperative staging). R1 (microscopic) and R2 (macroscopic) resections occurred in 20 (10%) and 6 patients (3%), respectively. Of several factors associated with R1 resections on univariate analysis, only total mesorectal excision (TME) specimen defects and threatened/involved CRM on preoperative imaging remained as independent predictors of R1 resections on multivariate analysis. Causes of R1 failure by MDT step classification found that less than half were associated with and only 15% solely attributable to a suboptimal TME specimen. Total mesorectal excision specimen defects and staging-predicted threatened or involved CRM are independent strong predictors of R1 resections. In most R1 resections, the TME specimen was intact. It is important to remember the contribution of both the local staging casemix and dCRT failure when using R1 rates to assess purely surgical competence.

  1. Development of methodology for characterization of cartridge filters from the IEA-R1 using the Monte Carlo method; Desenvolvimento de uma metodologia para caracterizacao do filtro cuno do reator IEA-R1 utilizando o Metodo Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Priscila

    2014-07-01

    The Cuno filter is part of the water processing circuit of the IEA-R1 reactor and, when saturated, it is replaced and becomes a radioactive waste, which must be managed. In this work, the primary characterization of the Cuno filter of the IEA-R1 nuclear reactor at IPEN was carried out using gamma spectrometry associated with the Monte Carlo method. The gamma spectrometry was performed using a hyperpure germanium detector (HPGe). The germanium crystal represents the detection active volume of the HPGe detector, which has a region called dead layer or inactive layer. It has been reported in the literature a difference between the theoretical and experimental values when obtaining the efficiency curve of these detectors. In this study we used the MCNP-4C code to obtain the detector calibration efficiency for the geometry of the Cuno filter, and the influence of the dead layer and the effect of sum in cascade at the HPGe detector were studied. The correction of the dead layer values were made by varying the thickness and the radius of the germanium crystal. The detector has 75.83 cm{sup 3} of active volume of detection, according to information provided by the manufacturer. Nevertheless, the results showed that the actual value of active volume is less than the one specified, where the dead layer represents 16% of the total volume of the crystal. A Cuno filter analysis by gamma spectrometry has enabled identifying energy peaks. Using these peaks, three radionuclides were identified in the filter: {sup 108m}Ag, {sup 110m}Ag and {sup 60}Co. From the calibration efficiency obtained by the Monte Carlo method, the value of activity estimated for these radionuclides is in the order of MBq. (author)

  2. Criticality analysis of the storage tubes for irradiated fuel elements from the IEA-R1 with the MCNP code

    International Nuclear Information System (INIS)

    Maragni, M.G.; Moreira, J.M.L.

    1992-01-01

    A criticality safety analysis has been carried out for the storage tubes for irradiated fuel elements from the IEA-R1 research reactor. The analysis utilized the MCNP computer code which allows exact simulations of complex geometries. Aiming reducing the amount of input data, the fuel element cross-sections have been spatially smeared out. The earth material interstice between fuel elements has been approximated conservatively as concrete because its composition was unknown. The storage tubes have been found subcritical for the most adverse conditions (water flooding and un-irradiated fuel elements). A similar analysis with the KENO-IV computer code overestimated the KEF result but still confirmed the criticality safety of the storage tubes. (author)

  3. Haplo-insufficiency of both BubR1 and SGO1 accelerates cellular senescence

    Directory of Open Access Journals (Sweden)

    Sung-Hyun Park

    2016-02-01

    Full Text Available Abstract Background Spindle assembly checkpoint components BubR1 and Sgo1 play a key role in the maintenance of chromosomal instability during cell division. These proteins function to block the anaphase entry until all condensed chromosomes have been attached by the microtubules emanating from both spindle poles. Haplo-insufficiency of either BubR1 or SGO1 results in enhanced chromosomal instability and tumor development in the intestine. Recent studies show that spindle checkpoint proteins also have a role in slowing down the ageing process. Therefore, we want to study whether haplo-insufficiency of both BubR1 and SGO1 accelerates cellular senescence in mice. Methods We took advantage of the availability of BubR1 and SGO1 knockout mice and generated primary murine embryonic fibroblasts (MEFs with mutations in either BubR1, SGO1, or both and analyzed cellular senescence of the MEFs of various genetic backgrounds. Results We observed that BubR1 +/− SGO +/− MEFs had an accelerated cellular senescence characterized by morphological changes and expressed senescence-associated β-galactosidase. In addition, compared with wild-type MEFs or MEFs with a single gene deficiency, BubR1 +/− SGO1 +/− MEFs expressed enhanced levels of p21 but not p16. Conclusions Taken together, our observations suggest that combined deficiency of BubR1 and Sgo1 accelerates cellular senescence.

  4. Szilard-Chalmers effect in solid H I O{sub 4}. 2 H{sub 2} O by neutron irradiation (source-reactor)

    Energy Technology Data Exchange (ETDEWEB)

    Takriti, S [radiochemistry laboratory, syrian atomic energy commission P.O. Box 6091 Damascus, (Syrian Arab Republic)

    1995-10-01

    The Szilard-Chalmers effect in solid periodic acid was investigated. In order to study the initial distribution of {sup 128I} o{sub 4} as a function of neutron flux, samples were irradiated utilizing both neutron source ({sup 241} Am-Be), the manual vertical irradiation channel and the thermal column of ET-R R-1 research reactor in Egypt. The initial retention reached a maximum of 40% after 120 minutes at 5.5 x 10 {sup 8} n s{sup -1} cm {sup -2}. The data was analysed using first order reaction. As a result, the activation Ko= 2.82 x 10 {sup 11} (S{sup -1}), respectively. Kinetics comparison of the dehydration and irradiation reactions for this solid showed disorder in the crystallographic form. Such disorder may be the result of dehydration or irradiation reactions, where the loss of water molecule will lead to formation of vacancies which, in turn, are responsible for the distribution process. 6 figs., 1 tab.

  5. Development of methodology for characterization of cartridge filters from the IEA-R1 using the Monte Carlo method

    International Nuclear Information System (INIS)

    Costa, Priscila

    2014-01-01

    The Cuno filter is part of the water processing circuit of the IEA-R1 reactor and, when saturated, it is replaced and becomes a radioactive waste, which must be managed. In this work, the primary characterization of the Cuno filter of the IEA-R1 nuclear reactor at IPEN was carried out using gamma spectrometry associated with the Monte Carlo method. The gamma spectrometry was performed using a hyperpure germanium detector (HPGe). The germanium crystal represents the detection active volume of the HPGe detector, which has a region called dead layer or inactive layer. It has been reported in the literature a difference between the theoretical and experimental values when obtaining the efficiency curve of these detectors. In this study we used the MCNP-4C code to obtain the detector calibration efficiency for the geometry of the Cuno filter, and the influence of the dead layer and the effect of sum in cascade at the HPGe detector were studied. The correction of the dead layer values were made by varying the thickness and the radius of the germanium crystal. The detector has 75.83 cm 3 of active volume of detection, according to information provided by the manufacturer. Nevertheless, the results showed that the actual value of active volume is less than the one specified, where the dead layer represents 16% of the total volume of the crystal. A Cuno filter analysis by gamma spectrometry has enabled identifying energy peaks. Using these peaks, three radionuclides were identified in the filter: 108m Ag, 110m Ag and 60 Co. From the calibration efficiency obtained by the Monte Carlo method, the value of activity estimated for these radionuclides is in the order of MBq. (author)

  6. Intelligence and Information-Sharing Elements of S.4 and H.R. 1

    National Research Council Canada - National Science Library

    Masse, Todd

    2007-01-01

    Title I of S.4 and Title VII of H.R. 1 include corresponding measures related to enhancing information and intelligence sharing, both horizontally within the Federal Government and vertically between the Federal Government and state...

  7. Mammalian ChlR1 has a role in heterochromatin organization

    International Nuclear Information System (INIS)

    Inoue, Akira; Hyle, Judith; Lechner, Mark S.; Lahti, Jill M.

    2011-01-01

    The ChlR1 DNA helicase, encoded by DDX11 gene, which is responsible for Warsaw breakage syndrome (WABS), has a role in sister-chromatid cohesion. In this study, we show that human ChlR1 deficient cells exhibit abnormal heterochromatin organization. While constitutive heterochromatin is discretely localized at perinuclear and perinucleolar regions in control HeLa cells, ChlR1-depleted cells showed dispersed localization of constitutive heterochromatin accompanied by disrupted centromere clustering. Cells isolated from Ddx11 -/- embryos also exhibited diffuse localization of centromeres and heterochromatin foci. Similar abnormalities were found in HeLa cells depleted of combinations of HP1α and HP1β. Immunofluorescence and chromatin immunoprecipitation showed a decreased level of HP1α at pericentric regions in ChlR1-depleted cells. Trimethyl-histone H3 at lysine 9 (H3K9-me3) was also modestly decreased at pericentric sequences. The abnormality in pericentric heterochromatin was further supported by decreased DNA methylation within major satellite repeats of Ddx11 -/- embryos. Furthermore, micrococcal nuclease (MNase) assay revealed a decreased chromatin density at the telomeres. These data suggest that in addition to a role in sister-chromatid cohesion, ChlR1 is also involved in the proper formation of heterochromatin, which in turn contributes to global nuclear organization and pleiotropic effects. -- Highlights: → New role for ChlR1 (DDX11), a cohesinopathy gene, in heterochromatin organization. → Loss of ChlR1 altered heterochromatin localization and centromere clustering. → Reduced ChlR1 levels also reduced HP1α and H3K9-me3 binding to pericentric DNA. → Decreased DNA methylation was found in pericentric repeats of Ddx11 -/- embryos. → These findings will aid in understanding the pathogenesis of Warsaw breakage syndrome.

  8. Manumycin A Is a Potent Inhibitor of Mammalian Thioredoxin Reductase-1 (TrxR-1).

    Science.gov (United States)

    Tuladhar, Anupama; Rein, Kathleen S

    2018-04-12

    The anticancer effect of manumycin A (Man A) has been attributed to the inhibition of farnesyl transferase (FTase), an enzyme that is responsible for post-translational modification of Ras proteins. However, we have discovered that Man A inhibits mammalian cytosolic thioredoxin reductase 1 (TrxR-1) in a time-dependent manner, with an IC 50 of 272 nM with preincubation and 1586 nM without preincubation. The inhibition of TrxR-1 by Man A is irreversible and is the result of a covalent interaction between Man A and TrxR-1. Evidence presented herein demonstrates that Man A forms a Michael adduct with the selenocysteine residue, which is located in the C-terminal redox center of TrxR-1. Inhibitors of TrxR-1, which act through this mechanism, convert TrxR-1 into a SecTRAP, which utilizes NADPH to reduce oxygen to superoxide radical anion (O 2 -• ).

  9. NEW DERIVATIVES OF 2-R1-N-(5-R-1,3,4-THIADIAZOL-2-YL-BENZOLSULFONAMIDES: SYNTHESIS, PHYSICOCHEMICAL PROPERTIES AND BIOLOGICAL ACTIVITY PREDICTION

    Directory of Open Access Journals (Sweden)

    Sych I.V.

    2015-12-01

    Full Text Available Introduction: The analysis of modern literature, including overseas one, showed that a lot of the scientific researches is devoted to finding and creating biologically active compounds on base 1,3,4-thiadiazole. Derivatives of 1,3,4-thiadiazole are the large group of heterocyclic compounds with high rates of antimicrobial, antituberculosis, antidiabetic, antineoplastic and anticonvulsant activity. Material and methods: The purpose of this study was the expansion of sulfone derivatives substituted nitrogen-containing heterocyclic systems through the synthesis of 2-R1-N (5-R-1,3,4-thiadiazol-2-ilbenzolsulfonamides and prediction their pharmacological activity for future planning pharmacological screening. Synthesis of semi-products 2-amino-5-R-1,3,4-thiadiazoles was carried out by cyclization thiosemicarbazide and substituted derivatives of carboxylic acids in the presence of concentrated sulfuric acid. The synthesis of target compounds 2-R1-N(5-R-1,3,4-thiadiazol-2-ylbenzolsulfon-amides was carried out by N-acylation of 2-amino-5R-1,3,4-thiadiazole substituted benzolsul-fochlorides in the presence of anhydrous pyridine. The reaction proceeds by the classic SN2-mechanism. The resulting compounds are white crystalline substances, soluble in alcohol, chloroform and acetone, difficult to dissolve in water. Yields of obtained compounds was satisfactory (76-84%. The purity of the obtained compounds was determined by TLC. The structure of the obtained compounds was proved by elemental analysis, IR methods and 1H NMR spectroscopy. NMR 1H spectra were recorded at Bruker WM spectrometer (200 MHz; solvent DMSO-d6; chemical shifts were in ppm, internal standard (TMS (tetramethylsilane was used. The prognosis of biological activity for obtained compounds were carried out using the program PASS (Prediction of Activity Spectra for Substances in order to plan the further pharmacological screening. The program PASS predicts more than 500 kinds of biological

  10. Alterations in CD200-CD200R1 System during EAE Already Manifest at Presymptomatic Stages

    Directory of Open Access Journals (Sweden)

    Tony Valente

    2017-05-01

    Full Text Available In the brain of patients with multiple sclerosis, activated microglia/macrophages appear in active lesions and in normal appearing white matter. However, whether they play a beneficial or a detrimental role in the development of the pathology remains a controversial issue. The production of pro-inflammatory molecules by chronically activated microglial cells is suggested to contribute to the progression of neurodegenerative processes in neurological disease. In the healthy brain, neurons control glial activation through several inhibitory mechanisms, such as the CD200-CD200R1 interaction. Therefore, we studied whether alterations in the CD200-CD200R1 system might underlie the neuroinflammation in an experimental autoimmune encephalomyelitis (EAE model of multiple sclerosis. We determined the time course of CD200 and CD200R1 expression in the brain and spinal cord of an EAE mouse model from presymptomatic to late symptomatic stages. We also assessed the correlation with associated glial activation, inflammatory response and EAE severity. Alterations in CD200 and CD200R1 expression were mainly observed in spinal cord regions in the EAE model, mostly a decrease in CD200 and an increase in CD200R1 expression. A decrease in the expression of the mRNA encoding a full CD200 protein was detected before the onset of clinical signs, and remained thereafter. A decrease in CD200 protein expression was observed from the onset of clinical signs. By contrast, CD200R1 expression increased at EAE onset, when a glial reaction associated with the production of pro- and anti-inflammatory markers occurred, and continued to be elevated during the pathology. Moreover, the magnitude of the alterations correlated with severity of the EAE mainly in spinal cord. These results suggest that neuronal-microglial communication through CD200-CD200R1 interaction is compromised in EAE. The early decreases in CD200 expression in EAE suggest that this downregulation might also

  11. Inhibition of CD200R1 expression by C/EBP beta in reactive microglial cells

    Directory of Open Access Journals (Sweden)

    Dentesano Guido

    2012-07-01

    Full Text Available Abstract Background In physiological conditions, it is postulated that neurons control microglial reactivity through a series of inhibitory mechanisms, involving either cell contact-dependent, soluble-factor-dependent or neurotransmitter-associated pathways. In the current study, we focus on CD200R1, a microglial receptor involved in one of these cell contact-dependent mechanisms. CD200R1 activation by its ligand, CD200 (mainly expressed by neurons in the central nervous system,is postulated to inhibit the pro-inflammatory phenotype of microglial cells, while alterations in CD200-CD200R1 signalling potentiate this phenotype. Little is known about the regulation of CD200R1 expression in microglia or possible alterations in the presence of pro-inflammatory stimuli. Methods Murine primary microglial cultures, mixed glial cultures from wild-type and CCAAT/enhancer binding protein β (C/EBPβ-deficient mice, and the BV2 murine cell line overexpressing C/EBPβ were used to study the involvement of C/EBPβ transcription factor in the regulation of CD200R1 expression in response to a proinflammatory stimulus (lipopolysaccharide (LPS. Binding of C/EBPβ to the CD200R1 promoter was determined by quantitative chromatin immunoprecipitation (qChIP. The involvement of histone deacetylase 1 in the control of CD200R1 expression by C/EBPβ was also determined by co-immunoprecipitation and qChIP. Results LPS treatment induced a decrease in CD200R1 mRNA and protein expression in microglial cells, an effect that was not observed in the absence of C/EBPβ. C/EBPβ overexpression in BV2 cells resulted in a decrease in basal CD200R1 mRNA and protein expression. In addition, C/EBPβ binding to the CD200R1 promoter was observed in LPS-treated but not in control glial cells, and also in control BV2 cells overexpressing C/EBPβ. Finally, we observed that histone deacetylase 1 co-immunoprecipitated with C/EBPβ and showed binding to a C/EBPβ consensus sequence of the CD

  12. C3a Enhances the Formation of Intestinal Organoids through C3aR1

    Directory of Open Access Journals (Sweden)

    Naoya Matsumoto

    2017-09-01

    Full Text Available C3a is important in the regulation of the immune response as well as in the development of organ inflammation and injury. Furthermore, C3a contributes to liver regeneration but its role in intestinal stem cell function has not been studied. We hypothesized that C3a is important for intestinal repair and regeneration. Intestinal organoid formation, a measure of stem cell capacity, was significantly limited in C3-deficient and C3a receptor (C3aR 1-deficient mice while C3a promoted the growth of organoids from normal mice by supporting Wnt-signaling but not from C3aR1-deficient mice. Similarly, the presence of C3a in media enhanced the expression of the intestinal stem cell marker leucine-rich repeat G-protein-coupled receptor 5 (Lgr5 and of the cell proliferation marker Ki67 in organoids formed from C3-deficient but not from C3aR1-deficient mice. Using Lgr5.egfp mice we showed significant expression of C3 in Lgr5+ intestinal stem cells whereas C3aR1 was expressed on the surface of various intestinal cells. C3 and C3aR1 expression was induced in intestinal crypts in response to ischemia/reperfusion injury. Finally, C3aR1-deficient mice displayed ischemia/reperfusion injury comparable to control mice. These data suggest that C3a through interaction with C3aR1 enhances stem cell expansion and organoid formation and as such may have a role in intestinal regeneration.

  13. Structure of IL-22 Bound to Its High-Affinity IL-22R1 Chain

    Energy Technology Data Exchange (ETDEWEB)

    Jones, B.C.; Logsdon, N.J.; Walter, M.R. (UAB)

    2008-09-29

    IL-22 is an IL-10 family cytokine that initiates innate immune responses against bacterial pathogens and contributes to immune disease. IL-22 biological activity is initiated by binding to a cell-surface complex composed of IL-22R1 and IL-10R2 receptor chains and further regulated by interactions with a soluble binding protein, IL-22BP, which shares sequence similarity with an extracellular region of IL-22R1 (sIL-22R1). IL-22R1 also pairs with the IL-20R2 chain to induce IL-20 and IL-24 signaling. To define the molecular basis of these diverse interactions, we have determined the structure of the IL-22/sIL-22R1 complex. The structure, combined with homology modeling and surface plasmon resonance studies, defines the molecular basis for the distinct affinities and specificities of IL-22 and IL-10 receptor chains that regulate cellular targeting and signal transduction to elicit effective immune responses.

  14. Protein-Nanocrystal Conjugates Support a Single Filament Polymerization Model in R1 Plasmid Segregation

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Charina L.; Claridge, Shelley A.; Garner, Ethan C.; Alivisatos, A. Paul; Mullins, R. Dyche

    2008-07-15

    To ensure inheritance by daughter cells, many low-copy number bacterial plasmids, including the R1 drug-resistance plasmid, encode their own DNA segregation systems. The par operon of plasmid R1 directs construction of a simple spindle structure that converts free energy of polymerization of an actin-like protein, ParM, into work required to move sister plasmids to opposite poles of rod-shaped cells. The structures of individual components have been solved, but little is known about the ultrastructure of the R1 spindle. To determine the number of ParM filaments in a minimal R1 spindle, we used DNA-gold nanocrystal conjugates as mimics of the R1 plasmid. Wefound that each end of a single polar ParM filament binds to a single ParR/parC-gold complex, consistent with the idea that ParM filaments bind in the hollow core of the ParR/parC ring complex. Our results further suggest that multifilament spindles observed in vivo are associated with clusters of plasmidssegregating as a unit.

  15. Hematopoietic stem cell gene therapy for IFNγR1 deficiency protects mice from mycobacterial infections.

    Science.gov (United States)

    Hetzel, Miriam; Mucci, Adele; Blank, Patrick; Nguyen, Ariane Hai Ha; Schiller, Jan; Halle, Olga; Kühnel, Mark-Philipp; Billig, Sandra; Meineke, Robert; Brand, Daniel; Herder, Vanessa; Baumgärtner, Wolfgang; Bange, Franz-Christoph; Goethe, Ralph; Jonigk, Danny; Förster, Reinhold; Gentner, Bernhard; Casanova, Jean-Laurent; Bustamante, Jacinta; Schambach, Axel; Kalinke, Ulrich; Lachmann, Nico

    2018-02-01

    Mendelian susceptibility to mycobacterial disease is a rare primary immunodeficiency characterized by severe infections caused by weakly virulent mycobacteria. Biallelic null mutations in genes encoding interferon gamma receptor 1 or 2 ( IFNGR1 or IFNGR2 ) result in a life-threatening disease phenotype in early childhood. Recombinant interferon γ (IFN-γ) therapy is inefficient, and hematopoietic stem cell transplantation has a poor prognosis. Thus, we developed a hematopoietic stem cell (HSC) gene therapy approach using lentiviral vectors that express Ifnγr1 either constitutively or myeloid specifically. Transduction of mouse Ifnγr1 -/- HSCs led to stable IFNγR1 expression on macrophages, which rescued their cellular responses to IFN-γ. As a consequence, genetically corrected HSC-derived macrophages were able to suppress T-cell activation and showed restored antimycobacterial activity against Mycobacterium avium and Mycobacterium bovis Bacille Calmette-Guérin (BCG) in vitro. Transplantation of genetically corrected HSCs into Ifnγr1 -/- mice before BCG infection prevented manifestations of severe BCG disease and maintained lung and spleen organ integrity, which was accompanied by a reduced mycobacterial burden in lung and spleen and a prolonged overall survival in animals that received a transplant. In summary, we demonstrate an HSC-based gene therapy approach for IFNγR1 deficiency, which protects mice from severe mycobacterial infections, thereby laying the foundation for a new therapeutic intervention in corresponding human patients. © 2018 by The American Society of Hematology.

  16. Nuclear reactors

    International Nuclear Information System (INIS)

    Barre, Bertrand

    2015-10-01

    After some remarks on the nuclear fuel, on the chain reaction control, on fuel loading and unloading, this article proposes descriptions of the design, principles and operations of different types of nuclear reactors as well as comments on their presence and use in different countries: pressurized water reactors (design of the primary and secondary circuits, volume and chemistry control, backup injection circuits), boiling water reactors, heavy water reactors, graphite and boiling water reactors, graphite-gas reactors, fast breeder reactors, and fourth generation reactors (definition, fast breeding). For these last ones, six concepts are presented: sodium-cooled fast reactor, lead-cooled fast reactor, gas-cooled fast reactor, high temperature gas-cooled reactor, supercritical water-cooled reactor, and molten salt reactor

  17. A Significant Role of the Truncated Ghrelin Receptor GHS-R1b in Ghrelin-induced Signaling in Neurons.

    Science.gov (United States)

    Navarro, Gemma; Aguinaga, David; Angelats, Edgar; Medrano, Mireia; Moreno, Estefanía; Mallol, Josefa; Cortés, Antonio; Canela, Enric I; Casadó, Vicent; McCormick, Peter J; Lluís, Carme; Ferré, Sergi

    2016-06-17

    The truncated non-signaling ghrelin receptor growth hormone secretagogue R1b (GHS-R1b) has been suggested to simply exert a dominant negative role in the trafficking and signaling of the full and functional ghrelin receptor GHS-R1a. Here we reveal a more complex modulatory role of GHS-R1b. Differential co-expression of GHS-R1a and GHS-R1b, both in HEK-293T cells and in striatal and hippocampal neurons in culture, demonstrates that GHS-R1b acts as a dual modulator of GHS-R1a function: low relative GHS-R1b expression potentiates and high relative GHS-R1b expression inhibits GHS-R1a function by facilitating GHS-R1a trafficking to the plasma membrane and by exerting a negative allosteric effect on GHS-R1a signaling, respectively. We found a preferential Gi/o coupling of the GHS-R1a-GHS-R1b complex in HEK-293T cells and, unexpectedly, a preferential Gs/olf coupling in both striatal and hippocampal neurons in culture. A dopamine D1 receptor (D1R) antagonist blocked ghrelin-induced cAMP accumulation in striatal but not hippocampal neurons, indicating the involvement of D1R in the striatal GHS-R1a-Gs/olf coupling. Experiments in HEK-293T cells demonstrated that D1R co-expression promotes a switch in GHS-R1a-G protein coupling from Gi/o to Gs/olf, but only upon co-expression of GHS-R1b. Furthermore, resonance energy transfer experiments showed that D1R interacts with GHS-R1a, but only in the presence of GHS-R1b. Therefore, GHS-R1b not only determines the efficacy of ghrelin-induced GHS-R1a-mediated signaling but also determines the ability of GHS-R1a to form oligomeric complexes with other receptors, promoting profound qualitative changes in ghrelin-induced signaling. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. A Significant Role of the Truncated Ghrelin Receptor GHS-R1b in Ghrelin-induced Signaling in Neurons*

    Science.gov (United States)

    Navarro, Gemma; Aguinaga, David; Angelats, Edgar; Medrano, Mireia; Moreno, Estefanía; Mallol, Josefa; Cortés, Antonio; Canela, Enric I.; Casadó, Vicent; McCormick, Peter J.; Lluís, Carme; Ferré, Sergi

    2016-01-01

    The truncated non-signaling ghrelin receptor growth hormone secretagogue R1b (GHS-R1b) has been suggested to simply exert a dominant negative role in the trafficking and signaling of the full and functional ghrelin receptor GHS-R1a. Here we reveal a more complex modulatory role of GHS-R1b. Differential co-expression of GHS-R1a and GHS-R1b, both in HEK-293T cells and in striatal and hippocampal neurons in culture, demonstrates that GHS-R1b acts as a dual modulator of GHS-R1a function: low relative GHS-R1b expression potentiates and high relative GHS-R1b expression inhibits GHS-R1a function by facilitating GHS-R1a trafficking to the plasma membrane and by exerting a negative allosteric effect on GHS-R1a signaling, respectively. We found a preferential Gi/o coupling of the GHS-R1a-GHS-R1b complex in HEK-293T cells and, unexpectedly, a preferential Gs/olf coupling in both striatal and hippocampal neurons in culture. A dopamine D1 receptor (D1R) antagonist blocked ghrelin-induced cAMP accumulation in striatal but not hippocampal neurons, indicating the involvement of D1R in the striatal GHS-R1a-Gs/olf coupling. Experiments in HEK-293T cells demonstrated that D1R co-expression promotes a switch in GHS-R1a-G protein coupling from Gi/o to Gs/olf, but only upon co-expression of GHS-R1b. Furthermore, resonance energy transfer experiments showed that D1R interacts with GHS-R1a, but only in the presence of GHS-R1b. Therefore, GHS-R1b not only determines the efficacy of ghrelin-induced GHS-R1a-mediated signaling but also determines the ability of GHS-R1a to form oligomeric complexes with other receptors, promoting profound qualitative changes in ghrelin-induced signaling. PMID:27129257

  19. The effect of anaesthesia on the radiosensitivity of rat intestine, foot skin and R-1 tumours

    International Nuclear Information System (INIS)

    Kal, H.B.; Gaiser, J.F.

    1980-01-01

    A comparison has been made of the effects of Nembutal (sodium pentobarbital) and Ethrane (2-chloro-1,1,2-trifluoroethyldifluoromethyl ether) anaesthesia on the radiation responses of rat intestine, foot skin and R-1 rhabdomyosarcoma. Single-dose experiments under Nembutal or short-lasting Ethrane anaesthesia resulted in equivalent radiosensitivities for the R-1 sarcoma and foot skin, whereas Ethrane induced radiosensitization in the intestine. In the Ethrane anaesthesia lasting 3 hours, and in the split-dose experiments, Ethrane inhibited repair of radiation-induced damage in the R-1 sarcoma and in the foot skin. It is therefore recommended that the use of Ethrane as an anaesthetic should be avoided in experiments designed to investigate repair of damage in fractionated studies or during protracted irradiation treatments. (UK)

  20. Deinococcus radiodurans strain R1 contains N6-methyladenine in its genome

    International Nuclear Information System (INIS)

    Prasad, Bhaskar Jyoti; Sabnis, Ketaki; Deobagkar, Deepti D.; Deobagkar, Dileep N.

    2005-01-01

    Methylation of DNA is known to be involved in DNA repair mechanisms in bacteria. Deinococcus radiodurans strain R1 on exposure to high radiation undergoes significant DNA damage, which is repaired without mutations. However, the presence of modified nucleotides has not been reported in its genome. We report here the detection of N6-methyladenine in the genome of D. radiodurans strain R1 using immunochemical techniques. This N6-methyladenine is not a part of GATC restriction-modification system. D. radiodurans cell extract also exhibited a DNA adenine methyltransferase activity which was reduced in the early post-irradiation recovery phase

  1. Monitoring conformational dynamics with solid-state R1ρ experiments

    International Nuclear Information System (INIS)

    Quinn, Caitlin M.; McDermott, Ann E.

    2009-01-01

    A new application of solid-state rotating frame (R 1ρ ) relaxation experiments to observe conformational dynamics is presented. Studies on a model compound, dimethyl sulfone (DMS), show that R 1ρ relaxation due to reorientation of a chemical shift anisotropy (CSA) tensor undergoing chemical exchange can be used to monitor slow-to-intermediate timescale conformational exchange processes. Control experiments used d 6 -DMS and alanine to confirm that the technique is monitoring reorientation of the CSA tensor rather than dipolar interactions or methyl group rotation. The application of this method to proteins could represent a new site-specific probe of conformational dynamics

  2. Les "Questions et réponses sur les évangiles" d'Eusèbe de Césarée: étude et édition du résumé grec

    OpenAIRE

    Zamagni, Claudio; Junod, Eric; Le Boulluec, Alain

    2005-01-01

    Cette thèse propose la première édition critique de l’une des traditions les plus importantes des Questions et réponses sur les évangiles d’Eusèbe de Césarée, dont l’original est perdu. Il s’agit de l’édition du manuscrit contenant l’anthologie grecque du manuscrit Vaticanus Pal. Gr. 220. Cette anthologie est composée presque intégralement d’une suite d’extraits du texte original, non résumés, dont l’auteur n’est pas Eusèbe et dont la date ne peut pas être reportée avant le V-VIème siècle. Ce...

  3. 26 CFR 31.3402(r)-1 - Withholding on distributions of Indian gaming profits to tribal members.

    Science.gov (United States)

    2010-04-01

    ... profits to tribal members. 31.3402(r)-1 Section 31.3402(r)-1 Internal Revenue INTERNAL REVENUE SERVICE... TAXES AND COLLECTION OF INCOME TAX AT SOURCE Collection of Income Tax at Source § 31.3402(r)-1 Withholding on distributions of Indian gaming profits to tribal members. (a) (1) General rule. Section 3402(r...

  4. Determination of taste receptor type 1 member 1 (TAS1R1) gene ...

    African Journals Online (AJOL)

    In this article, the objective was to investigate variations in goat TAS1R1 gene and their associations with growth traits in 317 goats by PCR-SSCP and DNA sequencing methods. The results showed two novel single nucleotide polymorphisms (SNPs): HM449123:g. [T3974C, C4037T]. In detail, two different alleles, A and B, ...

  5. Caracemide, a site-specific irreversible inhibitor of protein R1 of Escherichia coli ribonucleotide reductase

    DEFF Research Database (Denmark)

    Larsen, I. K.; Cornett, Claus; Karlsson, M.

    1992-01-01

    The anticancer drug caracemide, N-acetyl-N,O-di(methylcarbamoyl)hydroxylamine, and one of its degradation products, N-acetyl-O-methylcarbamoyl-hydroxylamine, were found to inhibit the enzyme ribonucleotide reductase of Escherichia coli by specific interaction with its larger component protein R1....

  6. Exact method for the simulation of Coulombic systems by spherically truncated, pairwise r-1 summation

    International Nuclear Information System (INIS)

    Wolf, D.; Keblinski, P.; Phillpot, S.R.; Eggebrecht, J.

    1999-01-01

    Based on a recent result showing that the net Coulomb potential in condensed ionic systems is rather short ranged, an exact and physically transparent method permitting the evaluation of the Coulomb potential by direct summation over the r -1 Coulomb pair potential is presented. The key observation is that the problems encountered in determining the Coulomb energy by pairwise, spherically truncated r -1 summation are a direct consequence of the fact that the system summed over is practically never neutral. A simple method is developed that achieves charge neutralization wherever the r -1 pair potential is truncated. This enables the extraction of the Coulomb energy, forces, and stresses from a spherically truncated, usually charged environment in a manner that is independent of the grouping of the pair terms. The close connection of our approach with the Ewald method is demonstrated and exploited, providing an efficient method for the simulation of even highly disordered ionic systems by direct, pairwise r -1 summation with spherical truncation at rather short range, i.e., a method which fully exploits the short-ranged nature of the interactions in ionic systems. The method is validated by simulations of crystals, liquids, and interfacial systems, such as free surfaces and grain boundaries. copyright 1999 American Institute of Physics

  7. Identifying the Proteins that Mediate the Ionizing Radiation Resistance of Deinococcus Radiodurans R1

    Energy Technology Data Exchange (ETDEWEB)

    Battista, John R

    2010-02-22

    The primary objectives of this proposal was to define the subset of proteins required for the ionizing radiation (IR) resistance of Deinococcus radiodurans R1, characterize the activities of those proteins, and apply what was learned to problems of interest to the Department of Energy.

  8. R1 Resection by Necessity for Colorectal Liver Metastases Is It Still a Contraindication to Surgery?

    NARCIS (Netherlands)

    de Haas, Robbert J.; Wicherts, Dennis A.; Flores, Eduardo; Azoulay, Daniel; Castaing, Denis; Adam, Rene

    2008-01-01

    Objective: To compare long-term outcome of R0 (negative margins) and R1 (positive margins) liver resections for colorectal liver metastases (CLM) treated by an aggressive approach combining chemotherapy and repeat surgery. Summary Background Data: Complete macroscopic resection with negative margins

  9. Structural and functional analysis of the kid toxin protein from E. coli Plasmid R1

    NARCIS (Netherlands)

    Hargreaves, D.; Santos-Sierra, S.; Giraldo, R.; Sabariegos-Jareño, R.; de la Cueva-Méndez, G.; Boelens, R.|info:eu-repo/dai/nl/070151407; Díaz-Orejas, R.; Rafferty, J.B.

    2002-01-01

    We have determined the structure of Kid toxin protein from E. coli plasmid R1 involved in stable plasmid inheritance by postsegregational killing of plasmid-less daughter cells. Kid forms a two-component system with its antagonist, Kis antitoxin. Our 1.4 Å crystal structure of Kid reveals a 2-fold

  10. Determination of taste receptor type 1 member 1 (TAS1R1) gene ...

    African Journals Online (AJOL)

    Jane

    2011-10-10

    Oct 10, 2011 ... 1Institute of Cellular and Molecular Biology, College of Life Science, Xuzhou Normal University, ... TAS1R1 and TAS1R3 form an L-amino acid sensor, ... 0.5 × TBE buffer (89 mM tris–borate, 2 mM EDTA, pH 8.3) for 2 h at.

  11. Retailing. Instructor's Guide Sheets and Instructor's Package, Modules R 1-45. Competency-Based Education.

    Science.gov (United States)

    Kentucky State Dept. of Education, Frankfort.

    This package contains instructor's guide sheets and student task assignment sheets for Modules R 1-45 of the competency-based curriculum in retailing developed for use in secondary and postsecondary schools in Kentucky. Some of the topics covered in the modules include the following: retailing--past, present, and future; retailing occupations;…

  12. Coordinated movement of cytoplasmic and transmembrane domains of RyR1 upon gating.

    Directory of Open Access Journals (Sweden)

    Montserrat Samsó

    2009-04-01

    Full Text Available Ryanodine receptor type 1 (RyR1 produces spatially and temporally defined Ca2+ signals in several cell types. How signals received in the cytoplasmic domain are transmitted to the ion gate and how the channel gates are unknown. We used EGTA or neuroactive PCB 95 to stabilize the full closed or open states of RyR1. Single-channel measurements in the presence of FKBP12 indicate that PCB 95 inverts the thermodynamic stability of RyR1 and locks it in a long-lived open state whose unitary current is indistinguishable from the native open state. We analyzed two datasets of 15,625 and 18,527 frozen-hydrated RyR1-FKBP12 particles in the closed and open conformations, respectively, by cryo-electron microscopy. Their corresponding three-dimensional structures at 10.2 A resolution refine the structure surrounding the ion pathway previously identified in the closed conformation: two right-handed bundles emerging from the putative ion gate (the cytoplasmic "inner branches" and the transmembrane "inner helices". Furthermore, six of the identifiable transmembrane segments of RyR1 have similar organization to those of the mammalian Kv1.2 potassium channel. Upon gating, the distal cytoplasmic domains move towards the transmembrane domain while the central cytoplasmic domains move away from it, and also away from the 4-fold axis. Along the ion pathway, precise relocation of the inner helices and inner branches results in an approximately 4 A diameter increase of the ion gate. Whereas the inner helices of the K+ channels and of the RyR1 channel cross-correlate best with their corresponding open/closed states, the cytoplasmic inner branches, which are not observed in the K+ channels, appear to have at least as important a role as the inner helices for RyR1 gating. We propose a theoretical model whereby the inner helices, the inner branches, and the h1 densities together create an efficient novel gating mechanism for channel opening by relaxing two right

  13. H Reactor

    Data.gov (United States)

    Federal Laboratory Consortium — The H Reactor was the first reactor to be built at Hanford after World War II.It became operational in October of 1949, and represented the fourth nuclear reactor on...

  14. CYP2R1 mutations causing vitamin D-deficiency rickets.

    Science.gov (United States)

    Thacher, Tom D; Levine, Michael A

    2017-10-01

    CYP2R1 is the principal hepatic 25-hydroxylase responsible for the hydroxylation of parent vitamin D to 25-hydroxyvitamin D [25(OH)D]. Serum concentrations of 25(OH)D reflect vitamin D status, because 25(OH)D is the major circulating metabolite of vitamin D. The 1α-hydroxylation of 25(OH)D in the kidney by CYP27B1 generates the fully active vitamin D metabolite, 1,25-dihydroxyvitamin D (1,25(OH) 2 D). The human CYP2R1 gene, located at 11p15.2, has five exons, coding for an enzyme with 501 amino acids. In Cyp2r1-/- knockout mice, serum 25(OH)D levels were reduced by more than 50% compared wild-type mice. Genetic polymorphisms of CYP2R1 account for some of the individual variability of circulating 25(OH)D values in the population. We review the evidence that inactivating mutations in CYP2R1 can lead to a novel form of vitamin D-deficiency rickets resulting from impaired 25-hydroxylation of vitamin D. We sequenced the promoter, exons and intron-exon flanking regions of the CYP2R1 gene in members of 12 Nigerian families with rickets in more than one family member. We found missense mutations (L99P and K242N) in affected members of 2 of 12 families. The L99P mutation had previously been reported as a homozygous defect in an unrelated child of Nigerian origin with rickets. In silico analyses predicted impaired CYP2R1 folding or reduced interaction with substrate vitamin D by L99P and K242N mutations, respectively. In vitro studies of the mutant CYP2R1 proteins in HEK293 cells confirmed normal expression levels but completely absent or markedly reduced 25-hydroxylase activity by the L99P and K242N mutations, respectively. Heterozygous subjects had more moderate biochemical and clinical features of vitamin D deficiency than homozygous subjects. After an oral bolus dose of 50,000 IU of vitamin D 2 or vitamin D 3 , heterozygous subjects had lower increases in serum 25(OH)D than control subjects, and homozygous subjects had minimal increases, supporting a semidominant

  15. Transport of UF6 in compliance with TS-R-1

    International Nuclear Information System (INIS)

    Dekker, B.G.

    2004-01-01

    The IAEA Regulations TS-R-1 (ST-1, Revised) 1996 Edition include requirements for packages containing uranium hexafluoride (UF6); these are the first and only substance-specific requirements in the IAEA regulations. These requirements have already particularly affected, and will further affect, the transport of non-fissile and fissile excepted UF 6 and the packages used for these transports. Non-fissile and fissile excepted UF6 (ASTM C 787) has been transported worldwide for decades in a safe and reliable manner, using internationally standardised packages. Under the auspices of the World Nuclear Transport Institute (WNTI), an industry working group has been evaluating the existing packages against the requirements in TS-R-1. As new requirements came into effect, there were new challenges for the use of these standard packages, including the free drop test and the thermal requirements. In close cooperation with the WNTI HEXT Industry Working Group, a consortium of UF6 producers/users has worked together on the design and development, testing and certification of technical solutions for modification and optimisation of the existing packages to comply with TS-R-1. This paper reviews the existing standard packages against the requirements in TS-R-1. An update is also given describing the enhancements to the standard packages that have been designed and developed recently. The paper also describes how these solutions have been tested and certified, as well as the status of implementation. Finally, a review is made of the options that are available internationally to transport UF6 in compliance with TS-R-1. (author)

  16. Ghrelin receptor (GHS-R1A) agonists show potential as interventive agents during aging.

    Science.gov (United States)

    Smith, Roy G; Sun, Yuxiang; Jiang, Hong; Albarran-Zeckler, Rosie; Timchenko, Nikolai

    2007-11-01

    Administration of an orally active agonist (MK-0677) of the growth hormone secretagogue receptor (GHS-R1a) to elderly subjects restored the amplitude of endogenous episodic growth hormone (GH) release to that of young adults. Functional benefits include increased lean mass and bone density and modest improvements in strength. In old mice, a similar agonist partially restored function to the thymus and reduced tumor cell growth and metastasis. Treatment of old mice with the endogenous GHS-R1a agonist ghrelin restored a young liver phenotype. The mechanism involves inhibition of cyclin D3:cdk4/cdk6 activity and increased protein phosphatase-2A (PP2A) activity in liver nuclei, which stabilizes the dephosphorylated form of the transcription factor C/EBPalpha preventing the age-dependent formation of the C/EBPalpha-Rb-E2F4-Brm nuclear complex. By inhibiting formation of this complex, repression of E2F target genes is de-repressed and C/EBPalpha regulated expression of Pepck, a regulator of gluconeogenesis, is normalized, thereby restoring a young liver phenotype. In the brain, aging is associated with decline in dopamine function. We investigated the potential neuromodulatory role of GHS-R1a on dopamine action. Neurons were identified in the hippocampus, cortex, substantia nigra, and ventral tegmental areas that coexpressed GHS-R1a and dopamine receptor subtype-1 (D1R). Cell culture studies showed that, in the presence of ghrelin and dopamine, GHS-R and D1R form heterodimers, which modified G-protein signal transduction resulting in amplification of dopamine signaling. We speculate that aging is associated with deficient endogenous ghrelin signaling that can be rescued by intervention with GHS-R1a agonists to improve quality of life and maintain independence.

  17. SKI - ASAR - R1. As operated Safety Analysis Report. Recurring safety review 1995 Ringhals 1

    International Nuclear Information System (INIS)

    2000-01-01

    According to Swedish law, the reactor owner is responsible for performing a safety review and writing a so called ASAR-report. The Nuclear Power Inspectorate (SKI) examines this report, and reports the findings to the government (the so called SKI-ASAR-report). Each Swedish reactor should pass through three full ASAR reviews during its lifetime, similar to the licensing inspection before start-up of the reactor. The second series ASAR was delivered by the Ringhals utility to SKI in September 1995, and forms the basis for the SKI analysis in the present report

  18. Nonlinear integral equations for thermodynamics of the sl(r + 1) Uimin-Sutherland model

    International Nuclear Information System (INIS)

    Tsuboi, Zengo

    2003-01-01

    We derive traditional thermodynamic Bethe ansatz (TBA) equations for the sl(r+1) Uimin-Sutherland model from the T-system of the quantum transfer matrix. These TBA equations are identical to the those from the string hypothesis. Next we derive a new family of nonlinear integral equations (NLIEs). In particular, a subset of these NLIEs forms a system of NLIEs which contains only a finite number of unknown functions. For r=1, this subset of NLIEs reduces to Takahashi's NLIE for the XXX spin chain. A relation between the traditional TBA equations and our new NLIEs is clarified. Based on our new NLIEs, we also calculate the high-temperature expansion of the free energy

  19. Stability Analysis of Landslide on the R1 Expressway by Limit Equilibrium and Finite Element Methods

    Science.gov (United States)

    Janták, Viktor

    2017-12-01

    The most difficult problem by designing the superior infrastructure is tracing the expressways and higways in an environment of Quaternary and Neogene complexes of finegrained cohesive and non-cohesive soils. At the last time the typical examples are stability problems on the R1 Nitra - Tekovské Nemce Expressway. The article is focused on the description of reasons of stability loss in the deep earth cut in the 79,000 km of expressway R1, the course of the landslide, slide correction and especially slope-stability assessment before and after the occurrence of slope failures by limit equilibrium and finite elements methods by comparing the behaviour of the slope in the various model situations.

  20. JESS-D-16-00343 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00343 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  1. JESS-D-16-00608 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00608 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  2. JESS-D-16-00592 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00592 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  3. JESS-D-16-00539 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00539 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  4. JESS-D-16-00583 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00583 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  5. JESS-D-16-00331R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00331R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  6. JESS-D-16-00216R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00216R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  7. JESS-D-16-00462 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00462 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  8. JESS-D-16-00615 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00615 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  9. JESS-D-16-00069 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

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  10. JESS-D-16-00237 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

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  11. JESS-D-16-00379 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

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  12. JESS-D-16-00205R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00205R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  13. JESS-D-16-00023 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00023 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  14. JESS-D-16-00602 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00602 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  15. JESS-D-16-00528 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00528 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  16. JESS-D-16-00272 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

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  17. JESS-D-16-00313 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00313 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  18. JESS-D-16-00432 R1.pdf;Structural | forthcoming | jess | Volumes ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00432 R1.pdf;Structural. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th ...

  19. JESS-D-16-00446 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

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  20. JESS-D-16-00496 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

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  1. JESS-D-16-00399R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00399R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  2. JESS-D-17-00004 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-17-00004 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  3. JESS-D-16-00451R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00451R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  4. Effects of heavy ions on inactivation and DNA double strand breaks in Deinococcus radiodurans R1.

    Science.gov (United States)

    Zimmermann, H; Schafer, M; Schmitz, C; Bucker, H

    1994-10-01

    Inactivation and double strand break (dsb) induction after heavy ion irradiation were studied in stationary phase cells of the highly radiation resistant bacterium Deinococcus radiodurans R1. There is evidence that the radiation sensitivity of this bacterium is nearly independent on energy in the range of up to 15 MeV/u for lighter ions (Ar). The responses to dsb induction for charged particles show direct relationship between increasing radiation dose and residual intact DNA.

  5. JESS-D-16-00170 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00170 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  6. JESS-D-16-00500 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00500 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  7. JESS-D-16-00199 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00199 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  8. JESS-D-16-00508 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00508 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  9. JESS-D-16-00457 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00457 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  10. JESS-D-16-00571 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00571 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  11. JESS-D-16-00396 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00396 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  12. JESS-D-16-00266R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00266R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  13. JESS-D-16-00432 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00432 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  14. JESS-D-16-00405 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00405 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  15. JESS-D-16-00485 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00485 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  16. JESS-D-16-00428 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00428 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  17. JESS-D-16-00082 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00082 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  18. JESS-D-16-00657 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00657 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  19. Design, fabrication, and testing of the PIACE-R1 machine

    International Nuclear Information System (INIS)

    Goto, S.; Uyama, T.; Yokota, T.; Takano, H.; Ohsaki, O.; Masuda, K.; Koyanagi, E.; Sanada, Y.

    1979-01-01

    The design, fabrication and testing of the coil and collector system for the PIACE-R1 (Plasma Injection and Compression Experiments-Race Track 1) are described in this paper. In particular, the eddy current analysis, collector insulation, and stress analysis for determining the coil configuration and arrangement are presented in detail. The purpose of the machine is to obtain thermonuclear plasmas. 5 refs

  20. JESS-D-16-00154R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00154R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  1. JESS-D-16-00162 R1.pdf | forthcoming | jess | Volumes | public ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; jess; forthcoming; JESS-D-16-00162 R1.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

  2. DIP1 modulates stem cell homeostasis in Drosophila through regulation of sisR-1.

    Science.gov (United States)

    Wong, Jing Ting; Akhbar, Farzanah; Ng, Amanda Yunn Ee; Tay, Mandy Li-Ian; Loi, Gladys Jing En; Pek, Jun Wei

    2017-10-02

    Stable intronic sequence RNAs (sisRNAs) are by-products of splicing and regulate gene expression. How sisRNAs are regulated is unclear. Here we report that a double-stranded RNA binding protein, Disco-interacting protein 1 (DIP1) regulates sisRNAs in Drosophila. DIP1 negatively regulates the abundance of sisR-1 and INE-1 sisRNAs. Fine-tuning of sisR-1 by DIP1 is important to maintain female germline stem cell homeostasis by modulating germline stem cell differentiation and niche adhesion. Drosophila DIP1 localizes to a nuclear body (satellite body) and associates with the fourth chromosome, which contains a very high density of INE-1 transposable element sequences that are processed into sisRNAs. DIP1 presumably acts outside the satellite bodies to regulate sisR-1, which is not on the fourth chromosome. Thus, our study identifies DIP1 as a sisRNA regulatory protein that controls germline stem cell self-renewal in Drosophila.Stable intronic sequence RNAs (sisRNAs) are by-products of splicing from introns with roles in embryonic development in Drosophila. Here, the authors show that the RNA binding protein DIP1 regulates sisRNAs in Drosophila, which is necessary for germline stem cell homeostasis.

  3. AHR prevents human IL-1R1hi ILC3 differentiation to natural killer cells

    Science.gov (United States)

    Hughes, Tiffany; Briercheck, Edward L.; Freud, Aharon G.; Trotta, Rossana; McClory, Susan; Scoville, Steven D.; Keller, Karen; Deng, Youcai; Cole, Jordan; Harrison, Nicholas; Mao, Charlene; Zhang, Jianying; Benson, Don M.; Yu, Jianhua; Caligiuri, Michael A.

    2014-01-01

    SUMMARY Accumulating evidence indicates that human natural killer (NK) cells develop in secondary lymphoid tissue (SLT) through a so-called “stage 3” developmental intermediate minimally characterized by a CD34-CD117+CD94- immunophenotype that lacks mature NK cell function. This stage 3 population is heterogeneous, potentially composed of functionally distinct innate lymphoid cell (ILC) types that includes interleukin-1 receptor (IL-1R1) positive, IL-22-producing ILC3s. Whether human ILC3s are developmentally related to NK cells is a subject of ongoing investigation. Here we show that antagonism of the aryl hydrocarbon receptor (AHR) or silencing of AHR gene expression promotes differentiation of tonsillar IL-22-producing IL-1R1hi human ILC3s to CD56brightCD94+ IFN-gamma-producing cytolytic mature NK cells expressing eomesodermin (EOMES) and T-Box Protein 21 (TBX21 or TBET). Hence, AHR is a transcription factor that prevents human IL-1R1hi ILC3s from differentiating into NK cells. PMID:24953655

  4. Thermotolerance and thermosensitization in CHO and R1H cells: a comparative study

    International Nuclear Information System (INIS)

    Dikomey, E.; Eickhoff, J.; Jung, H.

    1984-01-01

    In CHO and R1H cells thermotolerance was induced by a pre-incubation at 40 0 C, by an acute heat shock at 43 0 C followed by a time interval at 37 0 C, and during continuous heating at 42 0 C. Thermotolerance, which was tested at 43 0 , primarily causes an increase in D 0 of the heat-response curve. The degree of maximum thermotolerance was found to be generally more pronounced in CHO than in R1H cells, but the time interval at 37 0 C, as well as at 40 0 C, to reach this maximum level was the same in both cell lines. CHO and R1H cells could be sensitized to 40 0 C by a pre-treatment at 43 0 C. When compared for the same survival rate after pre-treatment at 43 0 C alone the degree of thermosensitization was about the same in both cell lines. In either cell line thermosensitization was found to be suppressed when cells were made thermotolerant by a previous incubation at 40 0 C for 16 hours. (author)

  5. The Indian origin of paternal haplogroup R1a1* substantiates the autochthonous origin of Brahmins and the caste system.

    Science.gov (United States)

    Sharma, Swarkar; Rai, Ekta; Sharma, Prithviraj; Jena, Mamata; Singh, Shweta; Darvishi, Katayoon; Bhat, Audesh K; Bhanwer, A J S; Tiwari, Pramod Kumar; Bamezai, Rameshwar N K

    2009-01-01

    Many major rival models of the origin of the Hindu caste system co-exist despite extensive studies, each with associated genetic evidences. One of the major factors that has still kept the origin of the Indian caste system obscure is the unresolved question of the origin of Y-haplogroup R1a1*, at times associated with a male-mediated major genetic influx from Central Asia or Eurasia, which has contributed to the higher castes in India. Y-haplogroup R1a1* has a widespread distribution and high frequency across Eurasia, Central Asia and the Indian subcontinent, with scanty reports of its ancestral (R*, R1* and R1a*) and derived lineages (R1a1a, R1a1b and R1a1c). To resolve these issues, we screened 621 Y-chromosomes (of Brahmins occupying the upper-most caste position and schedule castes/tribals occupying the lower-most positions) with 55 Y-chromosomal binary markers and seven Y-microsatellite markers and compiled an extensive dataset of 2809 Y-chromosomes (681 Brahmins, and 2128 tribals and schedule castes) for conclusions. A peculiar observation of the highest frequency (up to 72.22%) of Y-haplogroup R1a1* in Brahmins hinted at its presence as a founder lineage for this caste group. Further, observation of R1a1* in different tribal population groups, existence of Y-haplogroup R1a* in ancestors and extended phylogenetic analyses of the pooled dataset of 530 Indians, 224 Pakistanis and 276 Central Asians and Eurasians bearing the R1a1* haplogroup supported the autochthonous origin of R1a1 lineage in India and a tribal link to Indian Brahmins. However, it is important to discover novel Y-chromosomal binary marker(s) for a higher resolution of R1a1* and confirm the present conclusions.

  6. Nuclear reactors and fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-07-01

    The Nuclear Fuel Center (CCN) of IPEN produces nuclear fuel for the continuous operation of the IEA-R1 research reactor of IPEN. The serial production started in 1988, when the first nuclear fuel element was delivered for IEA-R1. In 2011, CCN proudly presents the 100{sup th} nuclear fuel element produced. Besides routine production, development of new technologies is also a permanent concern at CCN. In 2005, U{sub 3}O{sub 8} were replaced by U{sub 3}Si{sub 2}-based fuels, and the research of U Mo is currently under investigation. Additionally, the Brazilian Multipurpose Research Reactor (RMB), whose project will rely on the CCN for supplying fuel and uranium targets. Evolving from an annual production from 10 to 70 nuclear fuel elements, plus a thousand uranium targets, is a huge and challenging task. To accomplish it, a new and modern Nuclear Fuel Factory is being concluded, and it will provide not only structure for scaling up, but also a safer and greener production. The Nuclear Engineering Center has shown, along several years, expertise in the field of nuclear, energy systems and correlated areas. Due to the experience obtained during decades in research and technological development at Brazilian Nuclear Program, personnel has been trained and started to actively participate in design of the main system that will compose the Brazilian Multipurpose Reactor (RMB) which will make Brazil self-sufficient in production of radiopharmaceuticals. The institution has participated in the monitoring and technical support concerning the safety, licensing and modernization of the research reactors IPEN/MB-01 and IEA-R1. Along the last two decades, numerous specialized services of engineering for the Brazilian nuclear power plants Angra 1 and Angra 2 have been carried out. The contribution in service, research, training, and teaching in addition to the development of many related technologies applied to nuclear engineering and correlated areas enable the institution to

  7. Nuclear reactors and fuel cycle

    International Nuclear Information System (INIS)

    2014-01-01

    The Nuclear Fuel Center (CCN) of IPEN produces nuclear fuel for the continuous operation of the IEA-R1 research reactor of IPEN. The serial production started in 1988, when the first nuclear fuel element was delivered for IEA-R1. In 2011, CCN proudly presents the 100 th nuclear fuel element produced. Besides routine production, development of new technologies is also a permanent concern at CCN. In 2005, U 3 O 8 were replaced by U 3 Si 2 -based fuels, and the research of U Mo is currently under investigation. Additionally, the Brazilian Multipurpose Research Reactor (RMB), whose project will rely on the CCN for supplying fuel and uranium targets. Evolving from an annual production from 10 to 70 nuclear fuel elements, plus a thousand uranium targets, is a huge and challenging task. To accomplish it, a new and modern Nuclear Fuel Factory is being concluded, and it will provide not only structure for scaling up, but also a safer and greener production. The Nuclear Engineering Center has shown, along several years, expertise in the field of nuclear, energy systems and correlated areas. Due to the experience obtained during decades in research and technological development at Brazilian Nuclear Program, personnel has been trained and started to actively participate in design of the main system that will compose the Brazilian Multipurpose Reactor (RMB) which will make Brazil self-sufficient in production of radiopharmaceuticals. The institution has participated in the monitoring and technical support concerning the safety, licensing and modernization of the research reactors IPEN/MB-01 and IEA-R1. Along the last two decades, numerous specialized services of engineering for the Brazilian nuclear power plants Angra 1 and Angra 2 have been carried out. The contribution in service, research, training, and teaching in addition to the development of many related technologies applied to nuclear engineering and correlated areas enable the institution to fulfill its mission that is

  8. CD200R1 supports HSV-1 viral replication and licenses pro-inflammatory signaling functions of TLR2.

    Directory of Open Access Journals (Sweden)

    Roy J Soberman

    Full Text Available The CD200R1:CD200 axis is traditionally considered to limit tissue inflammation by down-regulating pro-inflammatory signaling in myeloid cells bearing the receptor. We generated CD200R1(-/- mice and employed them to explore both the role of CD200R1 in regulating macrophage signaling via TLR2 as well as the host response to an in vivo, TLR2-dependent model, herpes simplex virus 1 (HSV-1 infection. CD200R1(-/- peritoneal macrophages demonstrated a 70-75% decrease in the generation of IL-6 and CCL5 (Rantes in response to the TLR2 agonist Pam(2CSK(4 and to HSV-1. CD200R1(-/- macrophages could neither up-regulate the expression of TLR2, nor assemble a functional inflammasome in response to HSV-1. CD200R1(-/- mice were protected from HSV-1 infection and exhibited dysfunctional TLR2 signaling. Finally, both CD200R1(-/- mice and CD200R1(-/- fibroblasts and macrophages showed a markedly reduced ability to support HSV-1 replication. In summary, our data demonstrate an unanticipated and novel requirement for CD200R1 in "licensing" pro-inflammatory functions of TLR2 and in limiting viral replication that are supported by ex vivo and in vivo evidence.

  9. Reactor Physics

    International Nuclear Information System (INIS)

    Ait Abderrahim, A.

    2002-01-01

    SCK-CEN's Reactor Physics and MYRRHA Department offers expertise in various areas of reactor physics, in particular in neutron and gamma calculations, reactor dosimetry, reactor operation and control, reactor code benchmarking and reactor safety calculations. This expertise is applied in the Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 materials testing reactor dosimetry, and the preparation and interpretation of irradiation experiments by means of neutron and gamma calculations. The activities of the Fuzzy Logic and Intelligent Technologies in Nuclear Science programme cover several domains outside the department. Progress and achievements in these topical areas in 2001 are summarised

  10. Reactor Physics

    Energy Technology Data Exchange (ETDEWEB)

    Ait Abderrahim, A

    2001-04-01

    The Reactor Physics and MYRRHA Department of SCK-CEN offers expertise in various areas of reactor physics, in particular in neutronics calculations, reactor dosimetry, reactor operation, reactor safety and control and non-destructive analysis of reactor fuel. This expertise is applied in the Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 reactor dosimetry, and the preparation and interpretation of irradiation experiments by means of neutron and gamma calculations. The activities of the Fuzzy Logic and Intelligent Technologies in Nuclear Science programme cover several domains outside the department. Progress and achievements in these topical areas in 2000 are summarised.

  11. Reactor Physics

    Energy Technology Data Exchange (ETDEWEB)

    Ait Abderrahim, A

    2002-04-01

    SCK-CEN's Reactor Physics and MYRRHA Department offers expertise in various areas of reactor physics, in particular in neutron and gamma calculations, reactor dosimetry, reactor operation and control, reactor code benchmarking and reactor safety calculations. This expertise is applied in the Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 materials testing reactor dosimetry, and the preparation and interpretation of irradiation experiments by means of neutron and gamma calculations. The activities of the Fuzzy Logic and Intelligent Technologies in Nuclear Science programme cover several domains outside the department. Progress and achievements in these topical areas in 2001 are summarised.

  12. Reactor Physics

    International Nuclear Information System (INIS)

    Ait Abderrahim, A.

    2001-01-01

    The Reactor Physics and MYRRHA Department of SCK-CEN offers expertise in various areas of reactor physics, in particular in neutronics calculations, reactor dosimetry, reactor operation, reactor safety and control and non-destructive analysis of reactor fuel. This expertise is applied in the Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 reactor dosimetry, and the preparation and interpretation of irradiation experiments by means of neutron and gamma calculations. The activities of the Fuzzy Logic and Intelligent Technologies in Nuclear Science programme cover several domains outside the department. Progress and achievements in these topical areas in 2000 are summarised

  13. Reactor operation

    CERN Document Server

    Shaw, J

    2013-01-01

    Reactor Operation covers the theoretical aspects and design information of nuclear reactors. This book is composed of nine chapters that also consider their control, calibration, and experimentation.The opening chapters present the general problems of reactor operation and the principles of reactor control and operation. The succeeding chapters deal with the instrumentation, start-up, pre-commissioning, and physical experiments of nuclear reactors. The remaining chapters are devoted to the control rod calibrations and temperature coefficient measurements in the reactor. These chapters also exp

  14. Reactor safeguards

    CERN Document Server

    Russell, Charles R

    1962-01-01

    Reactor Safeguards provides information for all who are interested in the subject of reactor safeguards. Much of the material is descriptive although some sections are written for the engineer or physicist directly concerned with hazards analysis or site selection problems. The book opens with an introductory chapter on radiation hazards, the construction of nuclear reactors, safety issues, and the operation of nuclear reactors. This is followed by separate chapters that discuss radioactive materials, reactor kinetics, control and safety systems, containment, safety features for water reactor

  15. Nonlinear stochastic heat equations with cubic nonlinearities and additive Q-regular noise in R^1

    Directory of Open Access Journals (Sweden)

    Henri Schurz

    2010-09-01

    Full Text Available Semilinear stochastic heat equations perturbed by cubic-type nonlinearities and additive space-time noise with homogeneous boundary conditions are discussed in R^1. The space-time noise is supposed to be Gaussian in time and possesses a Fourier expansion in space along the eigenfunctions of underlying Lapace operators. We follow the concept of approximate strong (classical Fourier solutions. The existence of unique continuous L^2-bounded solutions is proved. Furthermore, we present a procedure for its numerical approximation based on nonstandard methods (linear-implicit and justify their stability and consistency. The behavior of related total energy functional turns out to be crucial in the presented analysis.

  16. A practical method to calculate the R1 index of waste-to-energy facilities.

    Science.gov (United States)

    Viganò, Federico

    2018-03-01

    According to Directive 98/2008/EC, the operation carried out by an incinerator of Municipal Solid Waste (MSW) is classified either as energy recovery (R1) or as disposal (D10) depending on the result achieved by the application of the R1 formula. In 2011 the DG Environment of the European Commission (EC) issued some non-binding guidelines on the interpretation of such a formula that clarified many aspects related to its application. A point not fully clarified by the EC guidelines is the determination of the energy contained in the treated waste (E W ). For this term of the formula, reference is made to the indirect method for the calculation of boiler thermal efficiency, as defined by the norm EN 12952-15. However, the application of such a norm to an entire year of operation of a Waste-to-Energy (WtE) boiler is not immediate. Therefore, a practical method for the calculation of the E W term has been developed in the framework of a collaboration between the MatER Study Centre and the Lombardy Region (Italy). The method is based on: (i) the identification of the most reliable data available from the Distributed Control System (DCS) of the plant; (ii) the definition of a control volume around the boiler(s) also based on the availability of data; (iii) the closure of the mass balance for such a control volume; (iv) the energy balance of the same control volume that gives, thus, the E W term of the R1 formula. The method has been applied in 2015-2016 to nine plants, generating a number of interesting data reported and discussed in this work, such as R1 index values, Lower Heating Values (LHV) of the treated wastes, main sources of energy losses in WtE boilers, etc. For one case study, discussed in detail in this work, the law of propagation of uncertainties has been applied according to the ISO/IEC Guide 98-3, leading to the assessment of the accuracy of the method, which resulted in ±2.4% with a confidence level of circa 95%. Copyright © 2017 Elsevier Ltd. All

  17. Naringenin degradation by the endophytic diazotroph Herbaspirillum seropedicae SmR1.

    Science.gov (United States)

    Marin, A M; Souza, E M; Pedrosa, F O; Souza, L M; Sassaki, G L; Baura, V A; Yates, M G; Wassem, R; Monteiro, R A

    2013-01-01

    Several bacteria are able to degrade flavonoids either to use them as carbon sources or as a detoxification mechanism. Degradation pathways have been proposed for several bacteria, but the genes responsible are not known. We identified in the genome of the endophyte Herbaspirillum seropedicae SmR1 an operon potentially associated with the degradation of aromatic compounds. We show that this operon is involved in naringenin degradation and that its expression is induced by naringenin and chrysin, two closely related flavonoids. Mutation of fdeA, the first gene of the operon, and fdeR, its transcriptional activator, abolished the ability of H. seropedicae to degrade naringenin.

  18. The Q Motif Is Involved in DNA Binding but Not ATP Binding in ChlR1 Helicase.

    Directory of Open Access Journals (Sweden)

    Hao Ding

    Full Text Available Helicases are molecular motors that couple the energy of ATP hydrolysis to the unwinding of structured DNA or RNA and chromatin remodeling. The conversion of energy derived from ATP hydrolysis into unwinding and remodeling is coordinated by seven sequence motifs (I, Ia, II, III, IV, V, and VI. The Q motif, consisting of nine amino acids (GFXXPXPIQ with an invariant glutamine (Q residue, has been identified in some, but not all helicases. Compared to the seven well-recognized conserved helicase motifs, the role of the Q motif is less acknowledged. Mutations in the human ChlR1 (DDX11 gene are associated with a unique genetic disorder known as Warsaw Breakage Syndrome, which is characterized by cellular defects in genome maintenance. To examine the roles of the Q motif in ChlR1 helicase, we performed site directed mutagenesis of glutamine to alanine at residue 23 in the Q motif of ChlR1. ChlR1 recombinant protein was overexpressed and purified from HEK293T cells. ChlR1-Q23A mutant abolished the helicase activity of ChlR1 and displayed reduced DNA binding ability. The mutant showed impaired ATPase activity but normal ATP binding. A thermal shift assay revealed that ChlR1-Q23A has a melting point value similar to ChlR1-WT. Partial proteolysis mapping demonstrated that ChlR1-WT and Q23A have a similar globular structure, although some subtle conformational differences in these two proteins are evident. Finally, we found ChlR1 exists and functions as a monomer in solution, which is different from FANCJ, in which the Q motif is involved in protein dimerization. Taken together, our results suggest that the Q motif is involved in DNA binding but not ATP binding in ChlR1 helicase.

  19. Preparation fo nuclear research reactors operators

    International Nuclear Information System (INIS)

    Roedel, G.

    1986-01-01

    The experience obtained with the training of operators of nuclear research reactors is presented. The main tool used in the experiments is the IPR-R1 reactor, a TRIGA MARK I type, owned by Nuclear Technology Development Centre (CDTN) of NUCLEBRAS. The structures of the Research Reactors Operators Training Course and of the Radiological Protection Course, as well as the Operators Qualifying and Requalifying Program, all of them prepared at CDTN are also presented. Mention is made of the application of similar experiments to other groups, such as students coming from Nuclear Sciences and Techniques Course of the Federal University of Minas Gerais. (Author) [pt

  20. Preparation of nuclear research reactors operators

    International Nuclear Information System (INIS)

    Roedel, G.

    1986-01-01

    The experience obtained with the training of operators of nuclear research reactors is presented. The main tool used in the experiments is the IPR-R1 reactor, a TRIGA MARK I type, owned by Nuclear Technology Development Centre (CDTN) of NUCLEBRAS. The structures of the Research Reactors Operators Training Course and of the Radiological Protection Course, as well as the Operators Qualifying and Requalifying Program, all of them prepared at CDTN, are also presented. Mention is made of the application of similar experiments to other groups, such as students coming from Nuclear Sciences and Techniques Course of the Federal University of Minas Gerais. (Author) [pt

  1. Nuclear reactors

    International Nuclear Information System (INIS)

    Middleton, J.E.

    1977-01-01

    Reference is made to water cooled reactors and in particular to the cooling system of steam generating heavy water reactors (SGHWR). A two-coolant circuit is described for the latter. Full constructural details are given. (U.K.)

  2. Reactor decommissioning

    International Nuclear Information System (INIS)

    Lawton, H.

    1984-01-01

    A pioneering project on the decommissioning of the Windscale Advanced Gas-cooled Reactor, by the UKAEA, is described. Reactor data; policy; waste management; remote handling equipment; development; and recording and timescales, are all briefly discussed. (U.K.)

  3. The Pseudomonas aeruginosa chemotaxis methyltransferase CheR1 impacts on bacterial surface sampling.

    Directory of Open Access Journals (Sweden)

    Juliane Schmidt

    Full Text Available The characterization of factors contributing to the formation and development of surface-associated bacterial communities known as biofilms has become an area of intense interest since biofilms have a major impact on human health, the environment and industry. Various studies have demonstrated that motility, including swimming, swarming and twitching, seems to play an important role in the surface colonization and establishment of structured biofilms. Thereby, the impact of chemotaxis on biofilm formation has been less intensively studied. Pseudomonas aeruginosa has a very complex chemosensory system with two Che systems implicated in flagella-mediated motility. In this study, we demonstrate that the chemotaxis protein CheR1 is a methyltransferase that binds S-adenosylmethionine and transfers a methyl group from this methyl donor to the chemoreceptor PctA, an activity which can be stimulated by the attractant serine but not by glutamine. We furthermore demonstrate that CheR1 does not only play a role in flagella-mediated chemotaxis but that its activity is essential for the formation and maintenance of bacterial biofilm structures. We propose a model in which motility and chemotaxis impact on initial attachment processes, dispersion and reattachment and increase the efficiency and frequency of surface sampling in P. aeruginosa.

  4. Observational evidence for supernova-induced star formation: Canis Major R1

    International Nuclear Information System (INIS)

    Herbst, W.; Assousa, G.E.

    1977-01-01

    The R association CMa R1, which contains two classical Herbig emission stars (Z CMa and HD 53367) and several other extremely young stellar objects, is found to lie at the edge of a large-scale ring of emission nebulosity. The form of the ring, which is also seen at radio wavelengths, and the absence of luminous stellar objects at its center suggest that it may be a relatively old supernova remnant (SNR). This suggestion is greatly strengthened by the discovery of an expanding H I shell coincident with the optical feature and the discovery of a runaway star, HD 54662, in CMa OB1. An age of order 5 x 10 5 years is derived for the SNR by comparing its properties with theoretical expectation based on models of SNRs evolving in a uniform medium. The close agreement between the likely ages of the stars and the age of the SNR, as well as the location of the recently formed objects with respect to the supernova shell, strongly support the hypothesis that a supernova event triggered star formation in CMa R1. Several other cases where evidence exists for supernova-induced star formation are briefly discussed, the most interesting being the Orion region where the hypothesis may provide a simple explanation for such diverse features as the runaway stars, Barnard's loop, and the gas kinematics and recent star formation in the Trapezium region

  5. [Activation of nucleolar organizers during in vitro cultivation of mouse R1 embryonic stem cells].

    Science.gov (United States)

    Kunafina, E R; Chaplina, M V; Filiasova, E I; Gibanova, N V; Khodarovich, Iu M; Larionov, O A; Zatsepina, O V

    2005-01-01

    We studies the activities of ribosomal genes (nucleolus forming regions of chromosomes) at successive stages of cultivation of the mouse R1 embryonic stem cells. The total number and number of active nucleolar organizers were estimated by means of in situ hybridization with mouse rDNA probes and argentophilic staining of nucleolus forming chromosomes regions from the 16th until the 32nd passages. The data we obtained suggest that the total number of nucleolar organizers per metaphase plate was constant (as a rule, eight), while the mean number of active nucleolar organizers progressively increased from the early (16th) to the late (32nd) passages: 5.2 +/- 0.4 versus 7.4 +/- 0.9 argentophilic organizers per cell. Cell heterogeneity by the number of active nucleolar organizers also increased during the late passages. Taken together, these data suggest activation of DNA transcription and synthesis of ribosomes during cultivation of mouse R1 embryonic stem cells. Based on the experimental and published data, it has been proposed that activation of ribosomal genes correlates in time with a decreased capacity of embryonic stem cells for pluripotent differentiation.

  6. Drosophila Polo regulates the spindle assembly checkpoint through Mps1-dependent BubR1 phosphorylation.

    Science.gov (United States)

    Conde, Carlos; Osswald, Mariana; Barbosa, João; Moutinho-Santos, Tatiana; Pinheiro, Diana; Guimarães, Sofia; Matos, Irina; Maiato, Helder; Sunkel, Claudio E

    2013-06-12

    Maintenance of genomic stability during eukaryotic cell division relies on the spindle assembly checkpoint (SAC) that prevents mitotic exit until all chromosomes are properly attached to the spindle. Polo is a mitotic kinase proposed to be involved in SAC function, but its role has remained elusive. We demonstrate that Polo and Aurora B functional interdependency comprises a positive feedback loop that promotes Mps1 kinetochore localization and activity. Expression of constitutively active Polo restores normal Mps1 kinetochore levels even after Aurora B inhibition, highlighting a role for Polo in Mps1 recruitment to unattached kinetochores downstream of Aurora B. We also show that Mps1 kinetochore localization is required for BubR1 hyperphosphorylation and formation of the 3F3/2 phosphoepitope. This is essential to allow recruitment of Cdc20 to unattached kinetochores and the assembly of anaphase-promoting complex/cyclosome-inhibitory complexes to levels that ensure long-term SAC activity. We propose a model in which Polo controls Mps1-dependent BubR1 phosphorylation to promote Cdc20 kinetochore recruitment and sustained SAC function.

  7. The PLA2R1-JAK2 pathway upregulates ERRα and its mitochondrial program to exert tumor-suppressive action.

    Science.gov (United States)

    Griveau, A; Devailly, G; Eberst, L; Navaratnam, N; Le Calvé, B; Ferrand, M; Faull, P; Augert, A; Dante, R; Vanacker, J M; Vindrieux, D; Bernard, D

    2016-09-22

    Little is known about the biological role of the phospholipase A2 receptor (PLA2R1) transmembrane protein. In recent years, PLA2R1 has been shown to have an important role in regulating tumor-suppressive responses via JAK2 activation, but the underlying mechanisms are largely undeciphered. In this study, we observed that PLA2R1 increases the mitochondrial content, judged by increased levels of numerous mitochondrial proteins, of the mitochondrial structural component cardiolipin, of the mitochondrial DNA content, and of the mitochondrial DNA replication and transcription factor TFAM. This effect of PLA2R1 relies on a transcriptional program controlled by the estrogen-related receptor alpha1 (ERRα) mitochondrial master regulator. Expression of ERRα and of its nucleus-encoded mitochondrial targets is upregulated upon PLA2R1 ectopic expression, and this effect is mediated by JAK2. Conversely, downregulation of PLA2R1 decreases the level of ERRα and of its nucleus-encoded mitochondrial targets. Finally, blocking the ERRα-controlled mitochondrial program largely inhibits the PLA2R1-induced tumor-suppressive response. Together, our data document ERRα and its mitochondrial program as downstream effectors of the PLA2R1-JAK2 pathway leading to oncosuppression.

  8. RA Reactor

    International Nuclear Information System (INIS)

    1978-02-01

    In addition to basic characteristics of the RA reactor, organizational scheme and financial incentives, this document covers describes the state of the reactor components after 18 years of operation, problems concerned with obtaining the licence for operation with 80% fuel, problems of spent fuel storage in the storage pool of the reactor building and the need for renewal of reactor equipment, first of all instrumentation [sr

  9. Multiregion reactors

    International Nuclear Information System (INIS)

    Moura Neto, C. de; Nair, R.P.K.

    1979-08-01

    The study of reflected reactors can be done employing the multigroup diffusion method. The neutron conservation equations, inside the intervals, can be written by fluxes and group constants. A reflected reactor (one and two groups) for a slab geometry is studied, aplying the continuity of flux and current in the interface. At the end, the appropriated solutions for a infinite cylindrical reactor and for a spherical reactor are presented. (Author) [pt

  10. Nuclear reactor

    International Nuclear Information System (INIS)

    Hattori, Sadao; Sato, Morihiko.

    1994-01-01

    Liquid metals such as liquid metal sodium are filled in a reactor container as primary coolants. A plurality of reactor core containers are disposed in a row in the circumferential direction along with the inner circumferential wall of the reactor container. One or a plurality of intermediate coolers are disposed at the inside of an annular row of the reactor core containers. A reactor core constituted with fuel rods and control rods (module reactor core) is contained at the inside of each of the reactor core containers. Each of the intermediate coolers comprises a cylindrical intermediate cooling vessels. The intermediate cooling vessel comprises an intermediate heat exchanger for heat exchange of primary coolants and secondary coolants and recycling pumps for compulsorily recycling primary coolants at the inside thereof. Since a plurality of reactor core containers are thus assembled, a great reactor power can be attained. Further, the module reactor core contained in one reactor core vessel may be small sized, to facilitate the control for the reactor core operation. (I.N.)

  11. Dansyl chloride labeling of Pseudomonas aeruginosa treated with pyocin R1: change in permeability of the cell envelope.

    Science.gov (United States)

    Uratani, Y

    1982-01-01

    Pyocin R1, a bacteriocin of Pseudomonas aeruginosa, caused an increase in binding of fluorescent label, 1-dimethylaminonaphthalene-5-sulfonyl chloride (dansyl chloride), to sensitive cells. In pyocin R1-treated cells, cytoplasmic soluble proteins and crude ribosomes as well as cell envelopes were labeled by dansyl chloride. The amount of bound dye was proportional to the multiplicity of pyocin R1 and reached a maximal level at high multiplicity. In addition, pyocin R1 rapidly caused an increase in fluorescence intensity of the hydrophobic probes N-phenyl-1-naphthylamine, pyrene, and perylene, which were mixed with cells. These results show that pyocin R1 damages locally a cell envelope barrier to hydrophobic solutes and allows dyes to penetrate into the intracellular space across the barrier. PMID:6799489

  12. Cointégration et causalité entre développement touristique, croissance économique et réduction de la pauvreté : cas de Haïti

    Directory of Open Access Journals (Sweden)

    Louis Dupont

    2011-08-01

    Full Text Available Cette étude emploie la théorie de la cointégration d’Engels et Granger pour analyser les relations entre développement touristique, croissance économique et réduction de la pauvreté en Haïti. Elle permet de tirer des enseignements et déduire des implications sur les liens de causalité entre ces trois variables. Les résultats montrent que ces dernières sont cointégrées et qu’au seuil de 5%, les relations, d’une part entre croissance économique et développement touristique sont unidirectionnelles, c'est-à-dire que la croissance économique engendre du développement touristique en Haïti et non l’inverse.  D’autre part, il existe également une relation unidirectionnelle entre réduction de la pauvreté et développement touristique. Autrement dit, la réduction de la pauvreté qui, souvent mais pas toujours dépend  de la croissance économique se traduirait ici par du développement touristique et non l’inverse.This study, using cointegration and causality tests, investigates the relationship among tourism development, economic expansion, and poverty reduction in Haïti. Empirical studies have shown that the three variables are cointegrated with a long-run stable relationship among the three. At 5% level, the causality tests suggest one-way Granger causal relation between economic growth and tourism development, and between poverty reduction and tourism development. On the other hand, the paper presents arguments in support of the proposition that poverty reduction as a source of tourism development, offers a convincing case for the use of policy instruments focused to drive a tourism-based economy.

  13. Nuclear power reactors

    International Nuclear Information System (INIS)

    1982-11-01

    After an introduction and general explanation of nuclear power the following reactor types are described: magnox thermal reactor; advanced gas-cooled reactor (AGR); pressurised water reactor (PWR); fast reactors (sodium cooled); boiling water reactor (BWR); CANDU thermal reactor; steam generating heavy water reactor (SGHWR); high temperature reactor (HTR); Leningrad (RMBK) type water-cooled graphite moderated reactor. (U.K.)

  14. Research reactors

    International Nuclear Information System (INIS)

    Merchie, Francois

    2015-10-01

    This article proposes an overview of research reactors, i.e. nuclear reactors of less than 100 MW. Generally, these reactors are used as neutron generators for basic research in matter sciences and for technological research as a support to power reactors. The author proposes an overview of the general design of research reactors in terms of core size, of number of fissions, of neutron flow, of neutron space distribution. He outlines that this design is a compromise between a compact enough core, a sufficient experiment volume, and high enough power densities without affecting neutron performance or its experimental use. The author evokes the safety framework (same regulations as for power reactors, more constraining measures after Fukushima, international bodies). He presents the main characteristics and operation of the two families which represent almost all research reactors; firstly, heavy water reactors (photos, drawings and figures illustrate different examples); and secondly light water moderated and cooled reactors with a distinction between open core pool reactors like Melusine and Triton, pool reactors with containment, experimental fast breeder reactors (Rapsodie, the Russian BOR 60, the Chinese CEFR). The author describes the main uses of research reactors: basic research, applied and technological research, safety tests, production of radio-isotopes for medicine and industry, analysis of elements present under the form of traces at very low concentrations, non destructive testing, doping of silicon mono-crystalline ingots. The author then discusses the relationship between research reactors and non proliferation, and finally evokes perspectives (decrease of the number of research reactors in the world, the Jules Horowitz project)

  15. Reactor physics and reactor computations

    International Nuclear Information System (INIS)

    Ronen, Y.; Elias, E.

    1994-01-01

    Mathematical methods and computer calculations for nuclear and thermonuclear reactor kinetics, reactor physics, neutron transport theory, core lattice parameters, waste treatment by transmutation, breeding, nuclear and thermonuclear fuels are the main interests of the conference

  16. Upper Campanian-Maastrichtian chronostratigraphy of the Skælskør-1 core, Denmark

    DEFF Research Database (Denmark)

    Thibault, Nicolas Rudolph; Anderskouv, Kresten; Bjerager, Morten

    2015-01-01

    The lithostratigraphy, calcareous nannofossil biostratigraphy, carbon- and oxygen-isotope stratigraphy and gamma-ray profile are presented for the Skælskør-1 core, eastern Denmark. The correlation of carbon isotopes to Gubbio (Italy) and ODP Site 762C (Indian Ocean) provides...... the chronostratigrahical framework of the core through a tie to magnetostratigraphy. Two new carbon-isotope excursions are defined for the uppermost Maastrichtian of the core and prove useful for long-distance correlation. Twenty stratigraphic tie-points are used for correlation of the upper Campanian......-Maastrichtian interval by combining carbon-isotope and gamma-ray variations. Significant dissimilarities in the gamma-ray profiles of the Danish Basin cores preclude the sole use of this tool for basin-scale correlations. Bulk oxygen-isotopes and semi-quantitative abundance changes in the warm-water calcareous...

  17. Temperature dependence of the chromium(III) R1 linewidth in emerald

    Science.gov (United States)

    Carceller-Pastor, Ivana; Hutchison, Wayne D.; Riesen, Hans

    2013-03-01

    The temperature dependent contribution to the R1 (2E ← 4A2) linewidth in emerald, Be3Al2Si6O18:Cr3, has been measured by employing spectral hole-burning, fluorescence line narrowing and conventional luminescence experiments. The contribution varies from 0.6 MHz at 6.5 K to ˜420 GHz at 240 K and the line red-shifts by ˜570 GHz. Above 60 K, the dependence is well described by a non-perturbative formalism for two-phonon Raman scattering. Below this temperature the direct one-phonon process between the levels of the split 2E excited state dominates. However, it appears that a localized low-energy phonon leads to a deviation from the standard pattern at lowest temperatures.

  18. Structure determination of the neutral exopolysaccharide produced by Lactobacillus delbrueckii subsp. bulgaricus OLL1073R-1.

    Science.gov (United States)

    Van Calsteren, Marie-Rose; Gagnon, Fleur; Nishimura, Junko; Makino, Seiya

    2015-09-02

    The neutral exopolysaccharide (NPS) of Lactobacillus delbrueckii subsp. bulgaricus strain OLL1073R-1 was purified and characterized. The molecular mass was 5.0×10(6) g/mol. Sugar and absolute configuration analyses gave the following composition: d-Glc, 1; d-Gal, 1.5. The NPS was also submitted to periodate oxidation followed by borohydride reduction and Smith degradation. Sugar and methylation analyses, (1)H and (13)C nuclear magnetic resonance, and mass spectrometry of the NPS or of its specifically modified products allowed determining the repeating unit sequence: {2)Glc(α1-3)Glc(β1-3)[Gal(β1-4)]Gal(β1-4)Gal(α1-}n. The structure is compared to that of exopolysaccharides produced by other Lactobacillus bulgaricus strains. Copyright © 2015. Published by Elsevier Ltd.

  19. Utilization of the IPR-RI research nuclear reactor in evaluation of Brazilian uranium reserves

    International Nuclear Information System (INIS)

    Carvalho Tofani, P. de; Stasiulevicius, R.

    1984-01-01

    Analytical techniques which were developed utilizing the IPR-R1 research reactor, are presented. These techniques determined the uranium contents and other chemical elements for several samples gathered in all national territory. (M.C.K) [pt

  20. High-resolution spectra of comet C/2013 R1 (Lovejoy)

    Science.gov (United States)

    Rousselot, P.; Decock, A.; Korsun, P. P.; Jehin, E.; Kulyk, I.; Manfroid, J.; Hutsemékers, D.

    2015-08-01

    Context. High-resolution spectra of comets permit deriving the physical properties of the coma. In the optical range, relative production rates can be computed, and information about isotopic ratios and the origin of oxygen atoms can be obtained. Aims: The main objective of the work presented here was to obtain information about the chemical composition of comet C/2013 R1 (Lovejoy), a bright and long-period comet that passed perihelion (0.81 au) on 22 December 2013. Methods: We used the HARPS-North echelle spectrograph at the 3.5 m telescope TNG to obtain high-resolution spectra of comet C/2013 R1 (Lovejoy) in the optical range immediately after its perihelion passage during four consecutive nights in the period December 23 to 26, 2013. Results: Our results demonstrate the ability of HARPS-North to efficiently obtain cometary spectra. Very faint emission lines, such as those of 15NH2, have been detected, leading to a rough estimate of the 14N/15N ratio in NH2. The 12C/13C ratio was measured in the C2 lines and is equal to 80 ± 30. The oxygen lines were studied as well (green to red line intensity ratios and widths), confirming that H2O is the main parent molecule that photodissociates to produce oxygen atoms. This suggests that this comet has a high CO2 abundance. Relative production rates for C2 and NH2 were computed, but we found no significant deviation from a typical NH2/C2 ratio. Based on observations made with the Italian Telescopio Nazionale Galileo (TNG) operated on the island of La Palma by the Fundación Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias.

  1. Solving the scalability issue in quantum-based refinement: Q|R#1.

    Science.gov (United States)

    Zheng, Min; Moriarty, Nigel W; Xu, Yanting; Reimers, Jeffrey R; Afonine, Pavel V; Waller, Mark P

    2017-12-01

    Accurately refining biomacromolecules using a quantum-chemical method is challenging because the cost of a quantum-chemical calculation scales approximately as n m , where n is the number of atoms and m (≥3) is based on the quantum method of choice. This fundamental problem means that quantum-chemical calculations become intractable when the size of the system requires more computational resources than are available. In the development of the software package called Q|R, this issue is referred to as Q|R#1. A divide-and-conquer approach has been developed that fragments the atomic model into small manageable pieces in order to solve Q|R#1. Firstly, the atomic model of a crystal structure is analyzed to detect noncovalent interactions between residues, and the results of the analysis are represented as an interaction graph. Secondly, a graph-clustering algorithm is used to partition the interaction graph into a set of clusters in such a way as to minimize disruption to the noncovalent interaction network. Thirdly, the environment surrounding each individual cluster is analyzed and any residue that is interacting with a particular cluster is assigned to the buffer region of that particular cluster. A fragment is defined as a cluster plus its buffer region. The gradients for all atoms from each of the fragments are computed, and only the gradients from each cluster are combined to create the total gradients. A quantum-based refinement is carried out using the total gradients as chemical restraints. In order to validate this interaction graph-based fragmentation approach in Q|R, the entire atomic model of an amyloid cross-β spine crystal structure (PDB entry 2oNA) was refined.

  2. Research reactors

    International Nuclear Information System (INIS)

    Kowarski, L.

    1955-01-01

    It brings together the techniques data which are involved in the discussion about the utility for a research institute to acquire an atomic reactor for research purposes. This type of decision are often taken by non-specialist people who can need a brief presentation of a research reactor and its possibilities in term of research before asking advises to experts. In a first part, it draws up a list of the different research programs which can be studied by getting a research reactor. First of all is the reactor behaviour and kinetics studies (reproducibility factor, exploration of neutron density, effect of reactor structure, effect of material irradiation...). Physical studies includes study of the behaviour of the control system, studies of neutron resonance phenomena and study of the fission process for example. Chemical studies involves the study of manipulation and control of hot material, characterisation of nuclear species produced in the reactor and chemical effects of irradiation on chemical properties and reactions. Biology and medicine research involves studies of irradiation on man and animals, genetics research, food or medical tools sterilization and neutron beams effect on tumour for example. A large number of other subjects can be studied in a reactor research as reactor construction material research, fabrication of radioactive sources for radiographic techniques or applied research as in agriculture or electronic. The second part discussed the technological considerations when choosing the reactor type. The technological factors, which are considered for its choice, are the power of the reactor, the nature of the fuel which is used, the type of moderator (water, heavy water, graphite or BeO) and the reflector, the type of coolants, the protection shield and the control systems. In the third part, it described the characteristics (place of installation, type of combustible and comments) and performance (power, neutron flux ) of already existing

  3. A structural model of the pore-forming region of the skeletal muscle ryanodine receptor (RyR1.

    Directory of Open Access Journals (Sweden)

    Srinivas Ramachandran

    2009-04-01

    Full Text Available Ryanodine receptors (RyRs are ion channels that regulate muscle contraction by releasing calcium ions from intracellular stores into the cytoplasm. Mutations in skeletal muscle RyR (RyR1 give rise to congenital diseases such as central core disease. The absence of high-resolution structures of RyR1 has limited our understanding of channel function and disease mechanisms at the molecular level. Here, we report a structural model of the pore-forming region of RyR1. Molecular dynamics simulations show high ion binding to putative pore residues D4899, E4900, D4938, and D4945, which are experimentally known to be critical for channel conductance and selectivity. We also observe preferential localization of Ca(2+ over K(+ in the selectivity filter of RyR1. Simulations of RyR1-D4899Q mutant show a loss of preference to Ca(2+ in the selectivity filter as seen experimentally. Electrophysiological experiments on a central core disease mutant, RyR1-G4898R, show constitutively open channels that conduct K(+ but not Ca(2+. Our simulations with G4898R likewise show a decrease in the preference of Ca(2+ over K(+ in the selectivity filter. Together, the computational and experimental results shed light on ion conductance and selectivity of RyR1 at an atomistic level.

  4. Unexpected dependence of RyR1 splice variant expression in human lower limb muscles on fiber-type composition.

    Science.gov (United States)

    Willemse, Hermia; Theodoratos, Angelo; Smith, Paul N; Dulhunty, Angela F

    2016-02-01

    The skeletal muscle ryanodine receptor Ca(2+) release channel (RyR1), essential for excitation-contraction (EC) coupling, demonstrates a known developmentally regulated alternative splicing in the ASI region. We now find unexpectedly that the expression of the splice variants is closely related to fiber type in adult human lower limb muscles. We examined the distribution of myosin heavy chain isoforms and ASI splice variants in gluteus minimus, gluteus medius and vastus medialis from patients aged 45 to 85 years. There was a strong positive correlation between ASI(+)RyR1 and the percentage of type 2 fibers in the muscles (r = 0.725), and a correspondingly strong negative correlation between the percentages of ASI(+)RyR1 and percentage of type 1 fibers. When the type 2 fiber data were separated into type 2X and type 2A, the correlation with ASI(+)RyR1 was stronger in type 2X fibers (r = 0.781) than in type 2A fibers (r = 0.461). There was no significant correlation between age and either fiber-type composition or ASI(+)RyR1/ASI(-)RyR1 ratio. The results suggest that the reduced expression of ASI(-)RyR1 during development may reflect a reduction in type 1 fibers during development. Preferential expression of ASI(-) RyR1, having a higher gain of in Ca(2+) release during EC coupling than ASI(+)RyR1, may compensate for the reduced terminal cisternae volume, fewer junctional contacts and reduced charge movement in type 1 fibers.

  5. The first Swedish nuclear reactor - from technical prototype to scientific instrument

    International Nuclear Information System (INIS)

    Fjaestad, M.

    2001-01-01

    The first Swedish reactor R1, constructed at the Royal Inst. of Technology in Stockholm, went critical in July 1954. This report presents historical aspects of the reactor, in particular about the reactor as a research instrument and a centre for physical science. The tensions between its role as a prototype and a step in the development of power reactors and that as a scientific instrument are especially focused

  6. Structural analysis of the as-built IEA-R1 primary coolant piping system using a complete three dimensional model

    International Nuclear Information System (INIS)

    Fainer, Gerson; Faloppa, Altair A.; Oliveira, Carlos A. de; Martins, Lucas B.; Marcolin, Gabriel; Mattar Neto, Miguel

    2011-01-01

    IEA-R1 is an open pool type research reactor, moderated by light water and upgraded from 2 MW to 5 MW of operating power level. Heat generated in the reactor core is removed by a coolant system divided in two circuits, primary and secondary, composed by pumps, piping, heat exchangers, cooling tower, and some other auxiliary components. The 5 MW operating power level is now possible due to a modernization program started in 1996. As a part of the modernization program, ageing assessment studies recommend the replacement of one of the two heat exchangers in the circuit. To manage this replacement, modifications in the layout of the primary and secondary piping and supporting systems were performed, based on preliminary stress analysis study. Then, the aim of this work is to present the final stress analysis of the primary circuit. To reach this and taking the modifications of the primary into account, a 3D model of the whole circuit, in the as-built condition, was made. Stress results and discussions are shown. (author)

  7. Reactor container

    International Nuclear Information System (INIS)

    Naruse, Yoshihiro.

    1990-01-01

    The thickness of steel shell plates in a reactor container embedded in sand cussions is monitored to recognize the corrosion of the steel shell plates. That is, the reactor pressure vessel is contained in a reactor container shell and the sand cussions are disposed on the lower outside of the reactor container shell to elastically support the shell. A pit is disposed at a position opposing to the sand cussions for measuring the thickness of the reactor container shell plates. The pit is usually closed by a closing member. In the reactor container thus constituted, the closing member can be removed upon periodical inspection to measure the thickness of the shell plates. Accordingly, the corrosion of the steel shell plates can be recognized by the change of the plate thickness. (I.S.)

  8. Hybrid reactors

    International Nuclear Information System (INIS)

    Moir, R.W.

    1980-01-01

    The rationale for hybrid fusion-fission reactors is the production of fissile fuel for fission reactors. A new class of reactor, the fission-suppressed hybrid promises unusually good safety features as well as the ability to support 25 light-water reactors of the same nuclear power rating, or even more high-conversion-ratio reactors such as the heavy-water type. One 4000-MW nuclear hybrid can produce 7200 kg of 233 U per year. To obtain good economics, injector efficiency times plasma gain (eta/sub i/Q) should be greater than 2, the wall load should be greater than 1 MW.m -2 , and the hybrid should cost less than 6 times the cost of a light-water reactor. Introduction rates for the fission-suppressed hybrid are usually rapid

  9. Nuclear reactor

    International Nuclear Information System (INIS)

    Garabedian, G.

    1988-01-01

    A liquid reactor is described comprising: (a) a reactor vessel having a core; (b) one or more satellite tanks; (c) pump means in the satellite tank; (d) heat exchanger means in the satellite tank; (e) an upper liquid metal conduit extending between the reactor vessel and the satellite tank; (f) a lower liquid metal duct extending between the reactor vessel and satellite tanks the upper liquid metal conduit and the lower liquid metal duct being arranged to permit free circulation of liquid metal between the reactor vessel core and the satellite tank by convective flow of liquid metal; (g) a separate sealed common containment vessel around the reactor vessel, conduits and satellite tanks; (h) the satellite tank having space for a volume of liquid metal that is sufficient to dampen temperature transients resulting from abnormal operating conditions

  10. A Saccharomyces cerevisiae Assay System to Investigate Ligand/AdipoR1 Interactions That Lead to Cellular Signaling

    KAUST Repository

    Aouida, Mustapha; Kim, Kangchang; Shaikh, Abdul Rajjak; Pardo, Jose M.; Eppinger, Jö rg; Yun, Dae-Jin; Bressan, Ray A.; Narasimhan, Meena L.

    2013-01-01

    Adiponectin is a mammalian hormone that exerts anti-diabetic, anti-cancer and cardioprotective effects through interaction with its major ubiquitously expressed plasma membrane localized receptors, AdipoR1 and AdipoR2. Here, we report a

  11. Nuclear reactor

    International Nuclear Information System (INIS)

    Batheja, P.; Huber, R.; Rau, P.

    1985-01-01

    Particularly for nuclear reactors of small output, the reactor pressure vessel contains at least two heat exchangers, which have coolant flowing through them in a circuit through the reactor core. The circuit of at least one heat exchanger is controlled by a slide valve, so that even for low drive forces, particularly in natural circulation, the required even loading of the heat exchanger is possible. (orig./HP) [de

  12. Defining the molecular basis of BubR1 kinetochore interactions and APC/C-CDC20 inhibition.

    Science.gov (United States)

    D'Arcy, Sheena; Davies, Owen R; Blundell, Tom L; Bolanos-Garcia, Victor M

    2010-05-07

    BubR1 is essential for the mitotic checkpoint that prevents aneuploidy in cellular progeny by triggering anaphase delay in response to kinetochores incorrectly/not attached to the mitotic spindle. Here, we define the molecular architecture of the functionally significant N-terminal region of human BubR1 and present the 1.8 A crystal structure of its tetratricopeptide repeat (TPR) domain. The structure reveals divergence from the classical TPR fold and is highly similar to the TPR domain of budding yeast Bub1. Shared distinctive features include a disordered loop insertion, a 3(10)-helix, a tight turn involving glycine positive Phi angles, and noncanonical packing of and between the TPR motifs. We also define the molecular determinants of the interaction between BubR1 and kinetochore protein Blinkin. We identify a shallow groove on the concave surface of the BubR1 TPR domain that forms multiple discrete and potentially cooperative interactions with Blinkin. Finally, we present evidence for a direct interaction between BubR1 and Bub1 mediated by regions C-terminal to their TPR domains. This interaction provides a mechanism for Bub1-dependent kinetochore recruitment of BubR1. We thus present novel molecular insights into the structure of BubR1 and its interactions at the kinetochore-microtubule interface. Our studies pave the way for future structure-directed engineering aimed at dissecting the roles of kinetochore-bound and other pools of BubR1 in vivo.

  13. R1 correction in amide proton transfer imaging: indication of the influence of transcytolemmal water exchange on CEST measurements.

    Science.gov (United States)

    Li, Hua; Li, Ke; Zhang, Xiao-Yong; Jiang, Xiaoyu; Zu, Zhongliang; Zaiss, Moritz; Gochberg, Daniel F; Gore, John C; Xu, Junzhong

    2015-12-01

    Amide proton transfer (APT) imaging may potentially detect mobile proteins/peptides non-invasively in vivo, but its specificity may be reduced by contamination from other confounding effects such as asymmetry of non-specific magnetization transfer (MT) effects and spin-lattice relaxation with rate R1 (=1/T1). Previously reported spillover, MT and R1 correction methods were based on a two-pool model, in which the existence of multiple water compartments with heterogeneous relaxation properties in real tissues was ignored. Such simple models may not adequately represent real tissues, and thus such corrections may be unreliable. The current study investigated the effectiveness and accuracy of correcting for R1 in APT imaging via simulations and in vivo experiments using tumor-bearing rats subjected to serial injections of Gd-DTPA that produced different tissue R1 values in regions of blood-brain-barrier breakdown. The results suggest that conventional measurements of APT contrast (such as APT* and MTRasym ) may be significantly contaminated by R1 variations, while the R1 -corrected metric AREX* was found to be relatively unaffected by R1 changes over a broad range (0.4-1 Hz). Our results confirm the importance of correcting for spin-lattice relaxation effects in quantitative APT imaging, and demonstrate the reliability of using the observed tissue R1 for corrections to obtain more specific and accurate measurements of APT contrast in vivo. The results also indicate that, due to relatively fast transcytolemmal water exchange, the influence of intra- and extracellular water compartments on CEST measurements with seconds long saturation time may be ignored in tumors. Copyright © 2015 John Wiley & Sons, Ltd.

  14. Heterogeneous reactors

    International Nuclear Information System (INIS)

    Moura Neto, C. de; Nair, R.P.K.

    1979-08-01

    The microscopic study of a cell is meant for the determination of the infinite multiplication factor of the cell, which is given by the four factor formula: K(infinite) = n(epsilon)pf. The analysis of an homogeneous reactor is similar to that of an heterogeneous reactor, but each factor of the four factor formula can not be calculated by the formulas developed in the case of an homogeneous reactor. A great number of methods was developed for the calculation of heterogeneous reactors and some of them are discussed. (Author) [pt

  15. Impaired associative fear learning in mice with complete loss or haploinsufficiency of AMPA GluR1 receptors

    Directory of Open Access Journals (Sweden)

    Michael Feyder

    2007-12-01

    Full Text Available There is compelling evidence that L-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA glutamate receptors containing the GluR1 subunit contribute to the molecular mechanisms associated with learning. AMPA GluR1 glutamate receptor knockout mice (KO exhibit abnormal hippocampal and amygdala plasticity, and deficits on various assays for cognition including Pavlovian fear conditioning. Here we examined associative fear learning in mice with complete absence (KO or partial loss (heterozygous mutant, HET of GluR1 on multiple fear conditioning paradigms. After multi-trial delay or trace conditioning, KO displayed impaired tone and context fear recall relative to WT, whereas HET were normal. After one-trial delay conditioning, both KO and HET showed impaired tone and context recall. HET and KO showed normal nociceptive sensitivity in the hot plate and tail flick tests. These data demonstrate that the complete absence of GluR1 subunit-containing receptors prevents the formation of associative fear memories, while GluR1 haploinsufficiency is sufficient to impair one-trial fear learning. These findings support growing evidence of a major role for GluR1-containing AMPA receptors in amygdalamediated forms of learning and memory.

  16. UV-dependent production of 25-hydroxyvitamin D2 in the recombinant yeast cells expressing human CYP2R1

    International Nuclear Information System (INIS)

    Yasuda, Kaori; Endo, Mariko; Ikushiro, Shinichi; Kamakura, Masaki; Ohta, Miho; Sakaki, Toshiyuki

    2013-01-01

    Highlights: •We produce 25-hydroxyvitamin D in the recombinant yeast expressing human CYP2R1. •Vitamin D2 is produced in yeast from endogenous ergosterol with UV irradiation. •We produce 25-hydroxyvitamin D2 in the recombinant yeast without added substrate. -- Abstract: CYP2R1 is known to be a physiologically important vitamin D 25-hydroxylase. We have successfully expressed human CYP2R1 in Saccharomyces cerevisiae to reveal its enzymatic properties. In this study, we examined production of 25-hydroxylated vitamin D using whole recombinant yeast cells that expressed CYP2R1. When vitamin D 3 or vitamin D 2 was added to the cell suspension of CYP2R1-expressing yeast cells in a buffer containing glucose and β-cyclodextrin, the vitamins were converted into their 25-hydroxylated products. Next, we irradiated the cell suspension with UVB and incubated at 37 °C. Surprisingly, the 25-hydroxy vitamin D 2 was produced without additional vitamin D 2 . Endogenous ergosterol was likely converted into vitamin D 2 by UV irradiation and thermal isomerization, and then the resulting vitamin D 2 was converted to 25-hydroxyvitamin D 2 by CYP2R1. This novel method for producing 25-hydroxyvitamin D 2 without a substrate could be useful for practical purposes

  17. Genome of Herbaspirillum seropedicae strain SmR1, a specialized diazotrophic endophyte of tropical grasses.

    Science.gov (United States)

    Pedrosa, Fábio O; Monteiro, Rose Adele; Wassem, Roseli; Cruz, Leonardo M; Ayub, Ricardo A; Colauto, Nelson B; Fernandez, Maria Aparecida; Fungaro, Maria Helena P; Grisard, Edmundo C; Hungria, Mariangela; Madeira, Humberto M F; Nodari, Rubens O; Osaku, Clarice A; Petzl-Erler, Maria Luiza; Terenzi, Hernán; Vieira, Luiz G E; Steffens, Maria Berenice R; Weiss, Vinicius A; Pereira, Luiz F P; Almeida, Marina I M; Alves, Lysangela R; Marin, Anelis; Araujo, Luiza Maria; Balsanelli, Eduardo; Baura, Valter A; Chubatsu, Leda S; Faoro, Helisson; Favetti, Augusto; Friedermann, Geraldo; Glienke, Chirlei; Karp, Susan; Kava-Cordeiro, Vanessa; Raittz, Roberto T; Ramos, Humberto J O; Ribeiro, Enilze Maria S F; Rigo, Liu Un; Rocha, Saul N; Schwab, Stefan; Silva, Anilda G; Souza, Eliel M; Tadra-Sfeir, Michelle Z; Torres, Rodrigo A; Dabul, Audrei N G; Soares, Maria Albertina M; Gasques, Luciano S; Gimenes, Ciela C T; Valle, Juliana S; Ciferri, Ricardo R; Correa, Luiz C; Murace, Norma K; Pamphile, João A; Patussi, Eliana Valéria; Prioli, Alberto J; Prioli, Sonia Maria A; Rocha, Carmem Lúcia M S C; Arantes, Olívia Márcia N; Furlaneto, Márcia Cristina; Godoy, Leandro P; Oliveira, Carlos E C; Satori, Daniele; Vilas-Boas, Laurival A; Watanabe, Maria Angélica E; Dambros, Bibiana Paula; Guerra, Miguel P; Mathioni, Sandra Marisa; Santos, Karine Louise; Steindel, Mario; Vernal, Javier; Barcellos, Fernando G; Campo, Rubens J; Chueire, Ligia Maria O; Nicolás, Marisa Fabiana; Pereira-Ferrari, Lilian; Silva, José L da Conceição; Gioppo, Nereida M R; Margarido, Vladimir P; Menck-Soares, Maria Amélia; Pinto, Fabiana Gisele S; Simão, Rita de Cássia G; Takahashi, Elizabete K; Yates, Marshall G; Souza, Emanuel M

    2011-05-01

    The molecular mechanisms of plant recognition, colonization, and nutrient exchange between diazotrophic endophytes and plants are scarcely known. Herbaspirillum seropedicae is an endophytic bacterium capable of colonizing intercellular spaces of grasses such as rice and sugar cane. The genome of H. seropedicae strain SmR1 was sequenced and annotated by The Paraná State Genome Programme--GENOPAR. The genome is composed of a circular chromosome of 5,513,887 bp and contains a total of 4,804 genes. The genome sequence revealed that H. seropedicae is a highly versatile microorganism with capacity to metabolize a wide range of carbon and nitrogen sources and with possession of four distinct terminal oxidases. The genome contains a multitude of protein secretion systems, including type I, type II, type III, type V, and type VI secretion systems, and type IV pili, suggesting a high potential to interact with host plants. H. seropedicae is able to synthesize indole acetic acid as reflected by the four IAA biosynthetic pathways present. A gene coding for ACC deaminase, which may be involved in modulating the associated plant ethylene-signaling pathway, is also present. Genes for hemagglutinins/hemolysins/adhesins were found and may play a role in plant cell surface adhesion. These features may endow H. seropedicae with the ability to establish an endophytic life-style in a large number of plant species.

  18. Genome of Herbaspirillum seropedicae strain SmR1, a specialized diazotrophic endophyte of tropical grasses.

    Directory of Open Access Journals (Sweden)

    Fábio O Pedrosa

    2011-05-01

    Full Text Available The molecular mechanisms of plant recognition, colonization, and nutrient exchange between diazotrophic endophytes and plants are scarcely known. Herbaspirillum seropedicae is an endophytic bacterium capable of colonizing intercellular spaces of grasses such as rice and sugar cane. The genome of H. seropedicae strain SmR1 was sequenced and annotated by The Paraná State Genome Programme--GENOPAR. The genome is composed of a circular chromosome of 5,513,887 bp and contains a total of 4,804 genes. The genome sequence revealed that H. seropedicae is a highly versatile microorganism with capacity to metabolize a wide range of carbon and nitrogen sources and with possession of four distinct terminal oxidases. The genome contains a multitude of protein secretion systems, including type I, type II, type III, type V, and type VI secretion systems, and type IV pili, suggesting a high potential to interact with host plants. H. seropedicae is able to synthesize indole acetic acid as reflected by the four IAA biosynthetic pathways present. A gene coding for ACC deaminase, which may be involved in modulating the associated plant ethylene-signaling pathway, is also present. Genes for hemagglutinins/hemolysins/adhesins were found and may play a role in plant cell surface adhesion. These features may endow H. seropedicae with the ability to establish an endophytic life-style in a large number of plant species.

  19. IFPE/TRIBULATION R1, Fuel Rod Behaviour at High Burnup

    International Nuclear Information System (INIS)

    Turnbull, J.A.

    2002-01-01

    Description: The TRIBULATION (Tests Relative to High Burnup Limitations Arising Normally in LWRs) International Programme started in July 1980 and was organized jointly by BelgoNucleaire and the Nuclear Energy Centre at Mol (CEN/SCK) with the co-sponsorship of 14 participating organizations. The objectives of the programme were twofold. It was primarily a demonstration programme aimed at assessing the fuel rod behaviour at high burn-up, when an earlier transient had occurred in the power plant. The second objective was to investigate the behaviour of different fuel rod designs and manufacturers when subjected to a steady state irradiation history to high burn-up. The first objective was met by irradiating fuel rods under steady state conditions in the BR3 reactor and under transient conditions in BR2. The effect of the transient was determined by comparing data from 4 identical rods tested as follows: i) BR3 irradiation followed by PIE; ii) BR3 irradiation followed by BR2 transient then PIE; iii) BR3 irradiation followed by BR2 transient and re-irradiated in BR3 before PIE; iv) BR3 irradiation and continued BR3 irradiation to maximum burn-up before PIE. The Database contains data from 19 cases using rods fabricated by BelgoNucleaire (BN) (11) and Brown Boveri Reactor GmbH (BBR) (8)

  20. LTB-R1: an alternative to swine mycoplasmal pneumoniae control LTB-R1: uma alternativa para o controle da pneumonia micoplásmica suína

    Directory of Open Access Journals (Sweden)

    Fabrício Rochedo Conceição

    2003-11-01

    Full Text Available Mycoplasmal pneumoniae is the main respiratory disease in swine. The most efficient way to control it is through the use of vaccines (bacterins, whose production cost is high. The objective of this work was to develop a new alternative for controlling Swine Mycoplasmal Pneumoniae, based on a recombinant subunit vaccine containing the R1 region of P97 adhesin of Mycoplasma hyopneumoniae fused to the B subunit of the heat-labile enterotoxin of Escherichia coli (rLTB-R1. In this work we report the amplification of the genes, genetic fusion between LTB and R1 coding sequences, cloning, construction of the expression vector, as well as expression and purification of rLTB-R1 in E. coli.A Pneumonia Micoplásmica é a doença respiratória mais importante dos suínos. A forma mais eficaz de controlá-la é mediante a utilização de vacinas (bacterinas, cujo custo de produção é elevado. Uma nova alternativa para o controle desta doença, baseada em uma vacina de subunidade recombinante contendo a região R1 da adesina P97 de Mycoplasma hyopneumoniae fusionada a subunidade B da enterotoxina termolábel de Escherichia coli (rLTB-R1, foi o alvo deste trabalho. Nele abordou-se a amplificação dos genes, a fusão genética entre as seqüências codificadoras para LTB e R1, a clonagem, a construção do vetor de expressão, assim como a expressão em E. coli e purificação da rLTBR1.

  1. miR-1 is increased in pulmonary hypertension and downregulates Kv1.5 channels in rat pulmonary arteries.

    Science.gov (United States)

    Mondejar-Parreño, Gema; Callejo, María; Barreira, Bianca; Morales-Cano, Daniel; Esquivel-Ruiz, Sergio; Moreno, Laura; Cogolludo, Angel; Perez-Vizcaino, Francisco

    2018-05-02

    ■The expression of miR-1 is increased in lungs from the Hyp/Su5416 PAH rat model. ■PASMC from this animal model are more depolarised and show decreased expression and activity of Kv1.5. ■miR-1 directly targets Kv1.5 channels, reduces Kv1.5 activity and induces membrane depolarization. ■Antagomir-1 prevents Kv1.5 channel downregulation and the depolarization induced by hypoxia/Su5416 exposition. Impairment of voltage-dependent potassium channel (Kv) plays a central role in the development of cardiovascular diseases, including pulmonary arterial hypertension (PAH). MicroRNAs (miRNAs) are non-coding RNAs that regulate gene expression by binding to the 3'-UTR region of specific mRNAs. The aim of this study was to analyze the effects of miR-1 on Kv channel function in pulmonary arteries (PA). Kv channel activity was studied in PA from healthy animals transfected with miR-1 or scrambled-miR. Kv currents were studied using the whole-cell configuration of patch-clamp technique. The characterization of the Kv1.5 currents was performed with the selective inhibitor DPO-1. miR-1 expression was increased and Kv1.5 channels were decreased in lungs from a rat model of PAH induced by hypoxia and Su5416. miR-1 transfection increased cell capacitance, reduced Kv1.5 currents and induced membrane depolarization in isolated pulmonary artery smooth muscle cells (PASMCs). Luciferase reporter assay indicated that KCNA5, which encodes Kv1.5 channels, is a direct target gene of miR-1. Incubation of PA with Su5416 and hypoxia (3% O 2 ) increased miR-1 and induced a decline in Kv1.5 currents, which was prevented by antagomiR-1. In conclusion, these data indicate that miR-1 induces PASMC hypertrophy and reduces the activity and expression of Kv channels, suggesting a pathophysiological role in PAH. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  2. Slurry reactors

    Energy Technology Data Exchange (ETDEWEB)

    Kuerten, H; Zehner, P [BASF A.G., Ludwigshafen am Rhein (Germany, F.R.)

    1979-08-01

    Slurry reactors are designed on the basis of empirical data and model investigations. It is as yet not possible to calculate the flow behavior of such reactors. The swarm of gas bubbles and cluster formations of solid particles and their interaction in industrial reactors are not known. These effects control to a large extent the gas hold-up, the gas-liquid interface and, similarly as in bubble columns, the back-mixing of liquids and solids. These hydrodynamic problems are illustrated in slurry reactors which constructionally may be bubble columns, stirred tanks or jet loop reactors. The expected effects are predicted by means of tests with model systems modified to represent the conditions in industrial hydrogenation reactors. In his book 'Mass Transfer in Heterogeneous Catalysis' (1970) Satterfield complained of the lack of knowledge about the design of slurry reactors and hence of the impossible task of the engineer who has to design a plant according to accepted rules. There have been no fundamental changes since then. This paper presents the problems facing the engineer in designing slurry reactors, and shows new development trends.

  3. Reactor safety

    International Nuclear Information System (INIS)

    Butz, H.P.; Heuser, F.W.; May, H.

    1985-01-01

    The paper comprises an introduction into nuclear physics bases, the safety concept generally speaking, safety devices of pwr type reactors, accident analysis, external influences, probabilistic safety assessment and risk studies. It further describes operational experience, licensing procedures under the Atomic Energy Law, research in reactor safety and the nuclear fuel cycle. (DG) [de

  4. Nuclear reactor

    International Nuclear Information System (INIS)

    Mysels, K.J.; Shenoy, A.S.

    1976-01-01

    A nuclear reactor is described in which the core consists of a number of fuel regions through each of which regulated coolant flows. The coolant from neighbouring fuel regions is combined in a manner which results in an averaging of the coolant temperature at the outlet of the core. By this method the presence of hot streaks in the reactor is reduced. (UK)

  5. Reactor container

    International Nuclear Information System (INIS)

    Kato, Masami; Nishio, Masahide.

    1987-01-01

    Purpose: To prevent the rupture of the dry well even when the melted reactor core drops into a reactor pedestal cavity. Constitution: In a reactor container in which a dry well disposed above the reactor pedestal cavity for containing the reactor pressure vessel and a torus type suppression chamber for containing pressure suppression water are connected with each other, the pedestal cavity and the suppression chamber are disposed such that the flow level of the pedestal cavity is lower than the level of the pressure suppression water. Further, a pressure suppression water introduction pipeway for introducing the pressure suppression water into the reactor pedestal cavity is disposed by way of an ON-OFF valve. In case if the melted reactor core should fall into the pedestal cavity, the ON-OFF valve for the pressure suppression water introduction pipeway is opened to introduce the pressure suppression water in the suppression chamber into the pedestal cavity to cool the melted reactor core. (Ikeda, J.)

  6. RA Reactor

    International Nuclear Information System (INIS)

    1989-01-01

    This chapter includes the following: General description of the RA reactor, organization of work, responsibilities of leadership and operators team, regulations concerning operation and behaviour in the reactor building, regulations for performing experiments, regulations and instructions for inserting samples into experimental channels [sr

  7. Reactor physics

    International Nuclear Information System (INIS)

    Ait Abderrahim, H.

    1998-01-01

    Progress in research on reactor physics in 1997 at the Belgian Nuclear Research Centre SCK/CEN is described. Activities in the following four domains are discussed: core physics, ex-core neutron transport, experiments in Materials Testing Reactors, international benchmarks

  8. Reactor core

    International Nuclear Information System (INIS)

    Azekura, Kazuo; Kurihara, Kunitoshi.

    1992-01-01

    In a BWR type reactor, a great number of pipes (spectral shift pipes) are disposed in the reactor core. Moderators having a small moderating cross section (heavy water) are circulated in the spectral shift pipes to suppress the excess reactivity while increasing the conversion ratio at an initial stage of the operation cycle. After the intermediate stage of the operation cycle in which the reactor core reactivity is lowered, reactivity is increased by circulating moderators having a great moderating cross section (light water) to extend the taken up burnup degree. Further, neutron absorbers such as boron are mixed to the moderator in the spectral shift pipe to control the concentration thereof. With such a constitution, control rods and driving mechanisms are no more necessary, to simplify the structure of the reactor core. This can increase the fuel conversion ratio and control great excess reactivity. Accordingly, a nuclear reactor core of high conversion and high burnup degree can be attained. (I.N.)

  9. Reactor container

    International Nuclear Information System (INIS)

    Fukazawa, Masanori.

    1991-01-01

    A system for controlling combustible gases, it has been constituted at present such that the combustible gases are controlled by exhausting them to the wet well of a reactor container. In this system, however, there has been a problem, in a reactor container having plenums in addition to the wet well and the dry well, that the combustible gases in such plenums can not be controlled. In view of the above, in the present invention, suction ports or exhaust ports of the combustible gas control system are disposed to the wet well, the dry well and the plenums to control the combustible gases in the reactor container. Since this can control the combustible gases in the entire reactor container, the integrity of the reactor container can be ensured. (T.M.)

  10. Reactor container

    International Nuclear Information System (INIS)

    Kojima, Yoshihiro; Hosomi, Kenji; Otonari, Jun-ichiro.

    1997-01-01

    In the present invention, a catalyst for oxidizing hydrogen to be disposed in a reactor container upon rupture of pipelines of a reactor primary coolant system is prevented from deposition of water droplets formed from a reactor container spray to suppress elevation of hydrogen concentration in the reactor container. Namely, a catalytic combustion gas concentration control system comprises a catalyst for oxidizing hydrogen and a support thereof. In addition, there is also disposed a water droplet deposition-preventing means for preventing deposition of water droplets in a reactor pressure vessel on the catalyst. Then, the effect of the catalyst upon catalytic oxidation reaction of hydrogen can be kept high. The local elevation of hydrogen concentration can be prevented even upon occurrence of such a phenomenon that various kinds of mobile forces in the container such as dry well cooling system are lost. (I.S.)

  11. Nuclear reactor

    International Nuclear Information System (INIS)

    Tilliette, Z.

    1975-01-01

    A description is given of a nuclear reactor and especially a high-temperature reactor in which provision is made within a pressure vessel for a main cavity containing the reactor core and a series of vertical cylindrical pods arranged in spaced relation around the main cavity and each adapted to communicate with the cavity through two collector ducts or headers for the primary fluid which flows downwards through the reactor core. Each pod contains two superposed steam-generator and circulator sets disposed in substantially symmetrical relation on each side of the hot primary-fluid header which conveys the primary fluid from the reactor cavity to the pod, the circulators of both sets being mounted respectively at the bottom and top ends of the pod

  12. Growth hormone-releasing hormone as an agonist of the ghrelin receptor GHS-R1a.

    Science.gov (United States)

    Casanueva, Felipe F; Camiña, Jesus P; Carreira, Marcos C; Pazos, Yolanda; Varga, Jozsef L; Schally, Andrew V

    2008-12-23

    Ghrelin synergizes with growth hormone-releasing hormone (GHRH) to potentiate growth hormone (GH) response through a mechanism not yet fully characterized. This study was conducted to analyze the role of GHRH as a potential ligand of the ghrelin receptor, GHS-R1a. The results show that hGHRH(1-29)NH(2) (GHRH) induces a dose-dependent calcium mobilization in HEK 293 cells stably transfected with GHS-R1a an effect not observed in wild-type HEK 293 cells. This calcium rise is also observed using the GHRH receptor agonists JI-34 and JI-36. Radioligand binding and cross-linking studies revealed that calcium response to GHRH is mediated by the ghrelin receptor GHS-R1a. GHRH activates the signaling route of inositol phosphate and potentiates the maximal response to ghrelin measured in inositol phosphate turnover. The presence of GHRH increases the binding capacity of (125)I-ghrelin in a dose dependent-fashion showing a positive binding cooperativity. In addition, confocal microscopy in CHO cells transfected with GHS-R1a tagged with enhanced green fluorescent protein shows that GHRH activates the GHS-R1a endocytosis. Furthermore, the selective GHRH-R antagonists, JV-1-42 and JMR-132, act also as antagonists of the ghrelin receptor GHS-R1a. Our findings suggest that GHRH interacts with ghrelin receptor GHS-R1a, and, in consequence, modifies the ghrelin-associated intracellular signaling pathway. This interaction may represent a form of regulation, which could play a putative role in the physiology of GH regulation and appetite control.

  13. p53-dependent inhibition of TrxR1 contributes to the tumor-specific induction of apoptosis by RITA.

    Science.gov (United States)

    Hedström, Elisabeth; Eriksson, Sofi; Zawacka-Pankau, Joanna; Arnér, Elias S J; Selivanova, Galina

    2009-11-01

    Thioredoxin reductase 1 (TrxR1) is a key regulator in many redox-dependent cellular pathways, and is often overexpressed in cancer. Several studies have identified TrxR1 as a potentially important target for anticancer therapy. The low molecular weight compound RITA (NSC 652287) binds p53 and induces p53-dependent apoptosis. Here we found that RITA also targets TrxR1 by non-covalent binding, followed by inhibition of its activity in vitro and by inhibition of TrxR activity in cancer cells. Interestingly, a novel approximately 130 kDa form of TrxR1, presumably representing a stable covalently linked dimer, and an increased generation of reactive oxygen species (ROS) were induced by RITA in cancer cells in a p53-dependent manner. Similarly, the gold-based TrxR inhibitor auranofin induced apoptosis related to oxidative stress, but independently of p53 and without apparent induction of the approximately 130 kDa form of TrxR1. In contrast to the effects observed in cancer cells, RITA did not inhibit TrxR or ROS formation in normal fibroblasts (NHDF). The inhibition of TrxR1 can sensitize tumor cells to agents that induce oxidative stress and may directly trigger cell death. Thus, our results suggest that a unique p53-dependent effect of RITA on TrxR1 in cancer cells might synergize with p53-dependent induction of pro-apoptotic genes and oxidative stress, thereby leading to a robust induction of cancer cell death, without affecting non-transformed cells.

  14. Improvement of Biodesulfurization Rate of Alginate Immobilized Rhodococcus erythropolis R1.

    Science.gov (United States)

    Derikvand, Peyman; Etemadifar, Zahra

    2014-03-01

    Sulfur oxides released from the burning of oil causes severe environmental pollution. The sulfur can be removed via the 4S pathway in biodesulfurization (BDS). Immobilization approaches have been developed to prevent cell contamination of oil during the BDS process. The encapsulation of Rhodococcus erythropolis R1 in calcium alginate beads was studied in order to enhance conversion of dibenzothiophene (DBT) to 2-hydroxy biphenyl (2-HBP) as the final product. Also the effect of different factors on the BDS process was investigated. Calcium alginate capsules were prepared using peristaltic pumps with different needle sizes to control the beads sizes. Scanning electron microscopy and flow cytometry methods were used to study the distribution and viability of encapsulated cells, respectively. Two non-ionic surfactants and also nano Ƴ-Al2O3were used with the ratio of 0.5% (v/v) and 1:5 (v/v) respectively to investigate their BDS efficiency. In addition, the effect of different bead sizes and different concentrations of sodium alginate in BDS activity was studied. The 2% (w/v) sodium alginate beads with 1.5mm size were found to be the optimum for beads stability and efficient 2-HBP production. The viability of encapsulated cells decreased by 12% after 20 h of desulfurization, compared to free cells. Adding the non-ionic surfactants markedly enhanced the rate of BDS, because of increasing mass transfer of DBT to the gel matrix. In addition, Span 80 was more effective than Tween 80. The nanoƳ-Al2O3 particles could increase BDS rate by up to two-folds greater than that of the control beads. The nano Ƴ-Al2O3 can improve the immobilized biocatalyst for excellent efficiency of DBT desulfurization. Also the BDS activity can be enhanced by setting the other explained factors at optimum levels.

  15. CO (3 – 2) HIGH-RESOLUTION SURVEY OF THE GALACTIC PLANE: R1

    Energy Technology Data Exchange (ETDEWEB)

    Dempsey, J. T.; Thomas, H. S.; Currie, M. J., E-mail: j.dempsey@jach.hawaii.edu, E-mail: h.thomas@jach.hawaii.edu, E-mail: m.currie@jach.hawaii.edu [Joint Astronomy Centre, 660 N. Aohoku Place, Hilo, HI 96720 (United States)

    2013-11-01

    We present the first release (R1) of data from the CO High-Resolution Survey (COHRS), which maps a strip of the inner Galactic plane in {sup 12}CO (J = 3 → 2). The data are taken using the Heterodyne Array Receiver Programme on the James Clerk Maxwell Telescope (JCMT) in Hawaii, which has a 14 arcsec angular resolution at this frequency. When complete, this survey will cover |b| ≤ 0.°5 between 10° < l < 65°. This first release covers |b| ≤ 0.°5 between 10.°25 < l < 17.°5 and 50.°25 < l < 55.°25, and |b| ≤ 0.°25 between 17.°5 < l < 50.°25. The data are smoothed to a velocity resolution of 1 km s{sup –1}, a spatial resolution of 16 arcsec and achieve a mean rms of ∼1 K. COHRS data are available to the community online at http://dx.doi.org/10.11570/13.0002. In this paper we describe the data acquisition and reduction techniques used and present integrated intensity images and longitude-velocity maps. We also discuss the noise characteristics of the data. The high resolution is a powerful tool for morphological studies of bubbles and filaments while the velocity information shows the spiral arms and outflows. These data are intended to complement both existing and upcoming surveys, e.g., the Bolocam Galactic Plane Survey (BGPS), ATLASGAL, the Herschel Galactic Plane Survey (Hi-GAL) and the JCMT Galactic Plane Survey with SCUBA-2 (JPS)

  16. Improvement of Biodesulfurization Rate of Alginate Immobilized Rhodococcus erythropolis R1

    Science.gov (United States)

    Derikvand, Peyman; Etemadifar, Zahra

    2014-01-01

    Background: Sulfur oxides released from the burning of oil causes severe environmental pollution. The sulfur can be removed via the 4S pathway in biodesulfurization (BDS). Immobilization approaches have been developed to prevent cell contamination of oil during the BDS process. Objectives: The encapsulation of Rhodococcus erythropolis R1 in calcium alginate beads was studied in order to enhance conversion of dibenzothiophene (DBT) to 2-hydroxy biphenyl (2-HBP) as the final product. Also the effect of different factors on the BDS process was investigated. Materials and Methods: Calcium alginate capsules were prepared using peristaltic pumps with different needle sizes to control the beads sizes. Scanning electron microscopy and flow cytometry methods were used to study the distribution and viability of encapsulated cells, respectively. Two non-ionic surfactants and also nano Ƴ-Al2O3were used with the ratio of 0.5% (v/v) and 1:5 (v/v) respectively to investigate their BDS efficiency. In addition, the effect of different bead sizes and different concentrations of sodium alginate in BDS activity was studied. Results: The 2% (w/v) sodium alginate beads with 1.5mm size were found to be the optimum for beads stability and efficient 2-HBP production. The viability of encapsulated cells decreased by 12% after 20 h of desulfurization, compared to free cells. Adding the non-ionic surfactants markedly enhanced the rate of BDS, because of increasing mass transfer of DBT to the gel matrix. In addition, Span 80 was more effective than Tween 80. The nanoƳ-Al2O3 particles could increase BDS rate by up to two-folds greater than that of the control beads. Conclusions: The nano Ƴ-Al2O3 can improve the immobilized biocatalyst for excellent efficiency of DBT desulfurization. Also the BDS activity can be enhanced by setting the other explained factors at optimum levels. PMID:25147685

  17. Élaboration d’indicateurs pour l’évaluation des collectivités-amies des aînés au Canada : démarche et résultats

    Directory of Open Access Journals (Sweden)

    H. Orpana

    2016-01-01

    Full Text Available Introduction : En 2006, l’Organisation mondiale de la Santé (OMS a lancé le projet mondial « Villes-amies des aînés » afin de favoriser un vieillissement actif. Si un grand nombre d’initiatives « amies des aînés » ont été mises en oeuvre au Canada, on dispose de peu d’information sur l’efficacité et les résultats des initiatives des collectivités-amies des aînés (CAA. En outre, les intervenants affirment qu’ils n’ont pas la capacité et les outils nécessaires pour élaborer et réaliser des évaluations relatives à leurs initiatives de CAA. Afin de pallier ces lacunes, l’Agence de la santé publique du Canada a mis au point des indicateurs pour l’évaluation des initiatives de CAA dans de nombreuses collectivités canadiennes. Ces indicateurs, destinés à répondre aux différents besoins des collectivités, ne sont pas conçus pour faire l’évaluation de répercussions collectives ou pour rendre possible une comparaison entre collectivités. Méthodologie : Une démarche de consultation itérative fondée sur des données probantes a été employée pour l’élaboration d’indicateurs relatifs aux CAA. Elle a nécessité une revue de la littérature et une analyse du contexte. Deux rondes de consultation auprès d’experts et d’intervenants clés ont été menées, ce qui a permis de classer les indicateurs potentiels en fonction de leur importance, de leur capacité à être mis en pratique et de leur faisabilité. Une liste définitive d’indicateurs et de mesures potentielles a ensuite été mise au point, en fonction des résultats de ces consultations et de considérations clés relatives aux politiques. Résultats : Trente-neuf indicateurs répartis en huit domaines relevant des CAA et quatre indicateurs relevant des résultats liés à la santé et aux conditions sociales à long terme ont été sélectionnés. Tous sont conformes à l’objectif énoncé, à savoir l’évaluation des

  18. DNA Methylation of T1R1 Gene in the Vegetarian Adaptation of Grass Carp Ctenopharyngodon idella.

    Science.gov (United States)

    Cai, Wenjing; He, Shan; Liang, Xu-Fang; Yuan, Xiaochen

    2018-05-02

    Although previous studies have indicated importance of taste receptors in food habits formation in mammals, little is known about those in fish. Grass carp is an excellent model for studying vegetarian adaptation, as it shows food habit transition from carnivore to herbivore. In the present study, pseudogenization or frameshift mutations of the umami receptors that hypothesized related to dietary switch in vertebrates, were not found in grass carp, suggesting other mechanisms for vegetarian adaptation in grass carp. T1R1 and T1R3 strongly responded to L-Arg and L-Lys, differing from those of zebrafish and medaka, contributing to high species specificity in amino acid preferences and diet selection of grass carp. After food habit transition of grass carp, DNA methylation levels were higher in CPG1 and CPG3 islands of upstream control region of T1R1 gene. Luciferase activity assay of upstream regulatory region of T1R1 (-2500-0 bp) without CPG1 or CPG3 indicated that CPG1 and CPG3 might be involved in transcriptional regulation of T1R1 gene. Subsequently, high DNA methylation decreased expression of T1R1 in intestinal tract. It could be a new mechanism to explain, at least partially, the vegetarian adaptation of grass carp by regulation of expression of umami receptor via epigenetic modification.

  19. Inhibition of IL-1R1/MyD88 signalling promotes mesenchymal stem cell-driven tissue regeneration.

    Science.gov (United States)

    Martino, Mikaël M; Maruyama, Kenta; Kuhn, Gisela A; Satoh, Takashi; Takeuchi, Osamu; Müller, Ralph; Akira, Shizuo

    2016-03-22

    Tissue injury and the healing response lead to the release of endogenous danger signals including Toll-like receptor (TLR) and interleukin-1 receptor, type 1 (IL-1R1) ligands, which modulate the immune microenvironment. Because TLRs and IL-1R1 have been shown to influence the repair process of various tissues, we explored their role during bone regeneration, seeking to design regenerative strategies integrating a control of their signalling. Here we show that IL-1R1/MyD88 signalling negatively regulates bone regeneration, in the mouse. Furthermore, IL-1β which is released at the bone injury site, inhibits the regenerative capacities of mesenchymal stem cells (MSCs). Mechanistically, IL-1R1/MyD88 signalling impairs MSC proliferation, migration and differentiation by inhibiting the Akt/GSK-3β/β-catenin pathway. Lastly, as a proof of concept, we engineer a MSC delivery system integrating inhibitors of IL-1R1/MyD88 signalling. Using this strategy, we considerably improve MSC-based bone regeneration in the mouse, demonstrating that this approach may be useful in regenerative medicine applications.

  20. Reactor building

    International Nuclear Information System (INIS)

    Maruyama, Toru; Murata, Ritsuko.

    1996-01-01

    In the present invention, a spent fuel storage pool of a BWR type reactor is formed at an upper portion and enlarged in the size to effectively utilize the space of the building. Namely, a reactor chamber enhouses reactor facilities including a reactor pressure vessel and a reactor container, and further, a spent fuel storage pool is formed thereabove. A second spent fuel storage pool is formed above the auxiliary reactor chamber at the periphery of the reactor chamber. The spent fuel storage pool and the second spent fuel storage pool are disposed in adjacent with each other. A wall between both of them is formed vertically movable. With such a constitution, the storage amount for spent fuels is increased thereby enabling to store the entire spent fuels generated during operation period of the plant. Further, since requirement of the storage for the spent fuels is increased stepwisely during periodical exchange operation, it can be used for other usage during the period when the enlarged portion is not used. (I.S.)

  1. Reactor container

    International Nuclear Information System (INIS)

    Shibata, Satoru; Kawashima, Hiroaki

    1984-01-01

    Purpose: To optimize the temperature distribution of the reactor container so as to moderate the thermal stress distribution on the reactor wall of LMFBR type reactor. Constitution: A good heat conductor (made of Al or Cu) is appended on the outer side of the reactor container wall from below the liquid level to the lower face of a deck plate. Further, heat insulators are disposed to the outside of the good heat conductor. Furthermore, a gas-cooling duct is circumferentially disposed at the contact portion between the good heat conductor and the deck plate around the reactor container. This enables to flow the cold heat from the liquid metal rapidly through the good heat conductor to the cooling duct and allows to maintain the temperature distribution on the reactor wall substantially linear even with the abrupt temperature change in the liquid metal. Further, by appending the good heat conductor covered with inactive metals not only on the outer side but also on the inside of the reactor wall to introduce the heat near the liquid level to the upper portion and escape the same to the cooling layer below the roof slab, the effect can be improved further. (Ikeda, J.)

  2. Nuclear reactor

    International Nuclear Information System (INIS)

    Rau, P.

    1980-01-01

    The reactor core of nuclear reactors usually is composed of individual elongated fuel elements that may be vertically arranged and through which coolant flows in axial direction, preferably from bottom to top. With their lower end the fuel elements gear in an opening of a lower support grid forming part of the core structure. According to the invention a locking is provided there, part of which is a control element that is movable along the fuel element axis. The corresponding locking element is engaged behind a lateral projection in the opening of the support grid. The invention is particularly suitable for breeder or converter reactors. (orig.) [de

  3. RMB. The new Brazilian multipurpose research reactor

    International Nuclear Information System (INIS)

    Perrotta, Jose Augusto; Soares, Adalberto Jose

    2015-01-01

    Brazil has four research reactors (RR) in operation: IEA-R1, a 5 MW pool type RR; IPR-R1, a 100 kW TRIGA type RR; ARGONAUTA, a 500 W Argonaut type RR, and IPEN/MB-01, a 100 W critical facility. The first three were constructed in the 50's and 60's, for teaching, training, and nuclear research, and for many years they were the basic infrastructure for the Brazilian nuclear developing program. The last, IPEN/MB-01, is the result of a national project developed specifically for qualification of reactor physics codes. Considering the relative low power of Brazilian research reactors, with exception of IEAR1, none of the other reactors are feasible for radioisotope production, and even IEA-R1 has a limited capacity. As a consequence, since long ago, 100% of the Mo-99 needed to attend Brazilian nuclear medicine services has been imported. Because of the high dependence on external supply, the international Moly-99 supply crisis that occurred in 2008/2009 affected significantly Brazilian nuclear medicine services, and as presented in previous IAEA events, in 2010 Brazilian government formalized the decision to build a new research reactor. The new reactor named RMB (Brazilian Multipurpose Reactor) will be a 30 MW open pool type reactor, using low enriched uranium fuel. The facility will be part of a new nuclear research centre, to be built about 100 kilometres from Sao Paulo city, in the southern part of Brazil. The new nuclear research centre will have several facilities, to use thermal and cold neutron beams; to produce radioisotopes; to perform neutron activation analysis; and to perform irradiations tests of materials and fuels of interest for the Brazilian nuclear program. An additional facility will be used to store, for at least 100 years, all the fuel used in the reactor. The paper describes the main characteristics of the new centre, emphasising the research reactor and giving a brief description of the laboratories that will be constructed, It also presents the

  4. RMB. The new Brazilian multipurpose research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Perrotta, Jose Augusto; Soares, Adalberto Jose [Comissao Nacional de Energia Nuclear (CNEN) (Brazil)

    2015-01-15

    Brazil has four research reactors (RR) in operation: IEA-R1, a 5 MW pool type RR; IPR-R1, a 100 kW TRIGA type RR; ARGONAUTA, a 500 W Argonaut type RR, and IPEN/MB-01, a 100 W critical facility. The first three were constructed in the 50's and 60's, for teaching, training, and nuclear research, and for many years they were the basic infrastructure for the Brazilian nuclear developing program. The last, IPEN/MB-01, is the result of a national project developed specifically for qualification of reactor physics codes. Considering the relative low power of Brazilian research reactors, with exception of IEAR1, none of the other reactors are feasible for radioisotope production, and even IEA-R1 has a limited capacity. As a consequence, since long ago, 100% of the Mo-99 needed to attend Brazilian nuclear medicine services has been imported. Because of the high dependence on external supply, the international Moly-99 supply crisis that occurred in 2008/2009 affected significantly Brazilian nuclear medicine services, and as presented in previous IAEA events, in 2010 Brazilian government formalized the decision to build a new research reactor. The new reactor named RMB (Brazilian Multipurpose Reactor) will be a 30 MW open pool type reactor, using low enriched uranium fuel. The facility will be part of a new nuclear research centre, to be built about 100 kilometres from Sao Paulo city, in the southern part of Brazil. The new nuclear research centre will have several facilities, to use thermal and cold neutron beams; to produce radioisotopes; to perform neutron activation analysis; and to perform irradiations tests of materials and fuels of interest for the Brazilian nuclear program. An additional facility will be used to store, for at least 100 years, all the fuel used in the reactor. The paper describes the main characteristics of the new centre, emphasising the research reactor and giving a brief description of the laboratories that will be constructed, It also

  5. Enhanced natural killer cell activation by exopolysaccharides derived from yogurt fermented with Lactobacillus delbrueckii ssp. bulgaricus OLL1073R-1.

    Science.gov (United States)

    Makino, Seiya; Sato, Asako; Goto, Ayako; Nakamura, Marie; Ogawa, Miho; Chiba, Yoshika; Hemmi, Jun; Kano, Hiroshi; Takeda, Kazuyoshi; Okumura, Ko; Asami, Yukio

    2016-02-01

    Yogurt is generally recognized as a beneficial food for our health, but research into its physiological effects has focused mainly on intestinal dysfunctions such as constipation and diarrhea. We previously found yogurt fermented with Lactobacillus delbrueckii ssp. bulgaricus OLL1073R-1 (hereafter OLL1073R-1) could reduce risks of catching the common cold and flu in human trials. It was assumed that immunostimulatory exopolysaccharide (EPS) produced from OLL1073R-1 play an important role in this context. However, few studies have examined the immunostimulatory effects of traditional Bulgarian yogurts fermented with different strains of lactobacilli and their metabolites. Therefore, we screened 139 L. delbrueckii ssp. bulgaricus strains and identified OLL1073R-1 as the most robust producer of EPS. This strain was also the only strain that induced the production of IFN-γ in vitro. Oral administration of the EPS or yogurt fermented with OLL1073R-1 and Streptococcus thermophilus OLS3059 (OLL1073R-1 yogurt) augmented natural killer (NK) cell activity and induced IFN-γ production in spleen cells in mice, whereas 2 other yogurts fermented with other strains had no effect on NK cell activity. Cellular preparations of the OLL1073R-1 strain also slightly augmented NK cell activity, but were less effective than EPS itself. The EPS-dependent stimulation of NK cell activity was abrogated in IFN-γ knockout mice and in myeloid differentiation factor 88 knockout mice. Furthermore, IFN-γ production from spleen cells stimulated with EPS was completely blocked with both anti-IL-12 and anti-IL-18 antibodies in vitro. These findings suggest that NK cell activation by OLL1073R-1 yogurt is EPS-dependent, occurs via IL-12- and IL-18-mediated IFN-γ production, and requires myeloid differentiation factor 88. We showed that traditional Bulgarian yogurt could exert immunostimulatory effects by selecting starter strains and part of the mechanisms depend on IFN-γ inducible EPS produced

  6. A Saccharomyces cerevisiae Assay System to Investigate Ligand/AdipoR1 Interactions That Lead to Cellular Signaling

    KAUST Repository

    Aouida, Mustapha

    2013-06-07

    Adiponectin is a mammalian hormone that exerts anti-diabetic, anti-cancer and cardioprotective effects through interaction with its major ubiquitously expressed plasma membrane localized receptors, AdipoR1 and AdipoR2. Here, we report a Saccharomyces cerevisiae based method for investigating agonist-AdipoR interactions that is amenable for high-throughput scale-up and can be used to study both AdipoRs separately. Agonist-AdipoR1 interactions are detected using a split firefly luciferase assay based on reconstitution of firefly luciferase (Luc) activity due to juxtaposition of its N- and C-terminal fragments, NLuc and CLuc, by ligand induced interaction of the chimeric proteins CLuc-AdipoR1 and APPL1-NLuc (adaptor protein containing pleckstrin homology domain, phosphotyrosine binding domain and leucine zipper motif 1-NLuc) in a S. cerevisiae strain lacking the yeast homolog of AdipoRs (Izh2p). The assay monitors the earliest known step in the adiponectin-AdipoR anti-diabetic signaling cascade. We demonstrate that reconstituted Luc activity can be detected in colonies or cells using a CCD camera and quantified in cell suspensions using a microplate reader. AdipoR1-APPL1 interaction occurs in absence of ligand but can be stimulated specifically by agonists such as adiponectin and the tobacco protein osmotin that was shown to have AdipoR-dependent adiponectin-like biological activity in mammalian cells. To further validate this assay, we have modeled the three dimensional structures of receptor-ligand complexes of membrane-embedded AdipoR1 with cyclic peptides derived from osmotin or osmotin-like plant proteins. We demonstrate that the calculated AdipoR1-peptide binding energies correlate with the peptides\\' ability to behave as AdipoR1 agonists in the split luciferase assay. Further, we demonstrate agonist-AdipoR dependent activation of protein kinase A (PKA) signaling and AMP activated protein kinase (AMPK) phosphorylation in S. cerevisiae, which are homologous to

  7. Oxygen-coupled Redox Regulation of the Skeletal Muscle Ryanodine Receptor/Ca2+ Release Channel (RyR1)

    Science.gov (United States)

    Sun, Qi-An; Wang, Benlian; Miyagi, Masaru; Hess, Douglas T.; Stamler, Jonathan S.

    2013-01-01

    In mammalian skeletal muscle, Ca2+ release from the sarcoplasmic reticulum (SR) through the ryanodine receptor/Ca2+-release channel RyR1 can be enhanced by S-oxidation or S-nitrosylation of separate Cys residues, which are allosterically linked. S-Oxidation of RyR1 is coupled to muscle oxygen tension (pO2) through O2-dependent production of hydrogen peroxide by SR-resident NADPH oxidase 4. In isolated SR (SR vesicles), an average of six to eight Cys thiols/RyR1 monomer are reversibly oxidized at high (21% O2) versus low pO2 (1% O2), but their identity among the 100 Cys residues/RyR1 monomer is unknown. Here we use isotope-coded affinity tag labeling and mass spectrometry (yielding 93% coverage of RyR1 Cys residues) to identify 13 Cys residues subject to pO2-coupled S-oxidation in SR vesicles. Eight additional Cys residues are oxidized at high versus low pO2 only when NADPH levels are supplemented to enhance NADPH oxidase 4 activity. pO2-sensitive Cys residues were largely non-overlapping with those identified previously as hyperreactive by administration of exogenous reagents (three of 21) or as S-nitrosylated. Cys residues subject to pO2-coupled oxidation are distributed widely within the cytoplasmic domain of RyR1 in multiple functional domains implicated in RyR1 activity-regulating interactions with the L-type Ca2+ channel (dihydropyridine receptor) and FK506-binding protein 12 as well as in “hot spot” regions containing sites of mutation implicated in malignant hyperthermia and central core disease. pO2-coupled disulfide formation was identified, whereas neither S-glutathionylated nor sulfenamide-modified Cys residues were observed. Thus, physiological redox regulation of RyR1 by endogenously generated hydrogen peroxide is exerted through dynamic disulfide formation involving multiple Cys residues. PMID:23798702

  8. Responses of rat R-1 cells to low dose rate gamma radiation and multiple daily dose fractions

    International Nuclear Information System (INIS)

    Kal, H.B.; Bijman, J.Th.

    1981-01-01

    Multifraction irradiation may offer the same therapeutic gain as continuous irradiation. Therefore, a comparison of the efficacy of low dose rate irradiation and multifraction irradiation was the main objective of the experiments to be described. Both regimens were tested on rat rhabdomyosarcoma (R-1) cells in vitro and in vivo. Exponentially growing R-1 cells were treated in vitro by a multifraction irradiation procedure with dose fractions of 2 Gy gamma radiation and time intervals of 1 to 3 h. The dose rate was 1.3 Gy.min -1 . The results indicate that multifractionation of the total dose is more effective with respect to cell inactivation than continuous irradiation. (Auth.)

  9. A Saccharomyces cerevisiae assay system to investigate ligand/AdipoR1 interactions that lead to cellular signaling.

    Directory of Open Access Journals (Sweden)

    Mustapha Aouida

    Full Text Available Adiponectin is a mammalian hormone that exerts anti-diabetic, anti-cancer and cardioprotective effects through interaction with its major ubiquitously expressed plasma membrane localized receptors, AdipoR1 and AdipoR2. Here, we report a Saccharomyces cerevisiae based method for investigating agonist-AdipoR interactions that is amenable for high-throughput scale-up and can be used to study both AdipoRs separately. Agonist-AdipoR1 interactions are detected using a split firefly luciferase assay based on reconstitution of firefly luciferase (Luc activity due to juxtaposition of its N- and C-terminal fragments, NLuc and CLuc, by ligand induced interaction of the chimeric proteins CLuc-AdipoR1 and APPL1-NLuc (adaptor protein containing pleckstrin homology domain, phosphotyrosine binding domain and leucine zipper motif 1-NLuc in a S. cerevisiae strain lacking the yeast homolog of AdipoRs (Izh2p. The assay monitors the earliest known step in the adiponectin-AdipoR anti-diabetic signaling cascade. We demonstrate that reconstituted Luc activity can be detected in colonies or cells using a CCD camera and quantified in cell suspensions using a microplate reader. AdipoR1-APPL1 interaction occurs in absence of ligand but can be stimulated specifically by agonists such as adiponectin and the tobacco protein osmotin that was shown to have AdipoR-dependent adiponectin-like biological activity in mammalian cells. To further validate this assay, we have modeled the three dimensional structures of receptor-ligand complexes of membrane-embedded AdipoR1 with cyclic peptides derived from osmotin or osmotin-like plant proteins. We demonstrate that the calculated AdipoR1-peptide binding energies correlate with the peptides' ability to behave as AdipoR1 agonists in the split luciferase assay. Further, we demonstrate agonist-AdipoR dependent activation of protein kinase A (PKA signaling and AMP activated protein kinase (AMPK phosphorylation in S. cerevisiae, which are

  10. Nuclear reactors

    International Nuclear Information System (INIS)

    Prescott, R.F.

    1976-01-01

    A nuclear reactor containment vessel faced internally with a metal liner is provided with thermal insulation for the liner, comprising one or more layers of compressible material such as ceramic fiber, such as would be conventional in an advanced gas-cooled reactor and also a superposed layer of ceramic bricks or tiles in combination with retention means therefor, the retention means (comprising studs projecting from the liner, and bolts or nuts in threaded engagement with the studs) being themselves insulated from the vessel interior so that the coolant temperatures achieved in a High-Temperature Reactor or a Fast Reactor can be tolerated with the vessel. The layer(s) of compressible material is held under a degree of compression either by the ceramic bricks or tiles themselves or by cover plates held on the studs, in which case the bricks or tiles are preferably bedded on a yielding layer (for example of carbon fibers) rather than directly on the cover plates

  11. Nuclear reactor

    International Nuclear Information System (INIS)

    Miyashita, Akio.

    1981-01-01

    Purpose: To facilitate and accelerate a leakage test of valves of a main steam pipe by adding a leakage test partition valve thereto. Constitution: A leakage testing partition valve is provided between a pressure vessel for a nuclear reactor and the most upstream side valve of a plurality of valves to be tested for leakage, a testing branch pipe is communicated with the downstream side of the partition valve, and the testing water for preventing leakage is introduced thereto through the branch pipe. Since main steam pipe can be simply isolated by closing the partition valve in the leakage test, the leakage test can be conducted without raising or lowering the water level in the pressure vessel, and since interference with other work in the reactor can be eliminated, the leakage test can be readily conducted parallel with other work in the reactor in a short time. Clean water can be used without using reactor water as the test water. (Yoshihara, H.)

  12. Reactor container

    International Nuclear Information System (INIS)

    Abe, Yoshihito; Sano, Tamotsu; Ueda, Sabuo; Tanaka, Kazuhisa.

    1987-01-01

    Purpose: To improve the liquid surface disturbance in LMFBR type reactors. Constitution: A horizontal flow suppressing mechanism mainly comprising vertical members is suspended near the free liquid surface of coolants in the upper plenum. The horizontal flow of coolants near the free liquid surface is reduced by the suppressing mechanism to effectively reduce the surface disturbance. The reduction in the liquid surface disturbance further prevails to the entire surface region with no particular vertical variations to the free liquid surface to remarkably improve the preventive performance for the liquid surface disturbance. Accordingly, it is also possible to attain the advantageous effects such as prevention for the thermal fatigue in reactor vessel walls, reactor upper mechanisms, etc. and prevention of burning damage to the reactor core due to the reduction of envolved Ar gas. (Kamimura, M.)

  13. REACTOR SHIELD

    Science.gov (United States)

    Wigner, E.P.; Ohlinger, L.E.; Young, G.J.; Weinberg, A.M.

    1959-02-17

    Radiation shield construction is described for a nuclear reactor. The shield is comprised of a plurality of steel plates arranged in parallel spaced relationship within a peripheral shell. Reactor coolant inlet tubes extend at right angles through the plates and baffles are arranged between the plates at right angles thereto and extend between the tubes to create a series of zigzag channels between the plates for the circulation of coolant fluid through the shield. The shield may be divided into two main sections; an inner section adjacent the reactor container and an outer section spaced therefrom. Coolant through the first section may be circulated at a faster rate than coolant circulated through the outer section since the area closest to the reactor container is at a higher temperature and is more radioactive. The two sections may have separate cooling systems to prevent the coolant in the outer section from mixing with the more contaminated coolant in the inner section.

  14. NUCLEAR REACTOR

    Science.gov (United States)

    Miller, H.I.; Smith, R.C.

    1958-01-21

    This patent relates to nuclear reactors of the type which use a liquid fuel, such as a solution of uranyl sulfate in ordinary water which acts as the moderator. The reactor is comprised of a spherical vessel having a diameter of about 12 inches substantially surrounded by a reflector of beryllium oxide. Conventionnl control rods and safety rods are operated in slots in the reflector outside the vessel to control the operation of the reactor. An additional means for increasing the safety factor of the reactor by raising the ratio of delayed neutrons to prompt neutrons, is provided and consists of a soluble sulfate salt of beryllium dissolved in the liquid fuel in the proper proportion to obtain the result desired.

  15. Site Investigation for Detection of KIJANG Reactor Core Center

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Tae-Hyun; Kim, Jun Yeon; Kim, Jeeyoung [KAERI, Daejeon (Korea, Republic of)

    2015-05-15

    It was planned for the end of March 2017 and extended to April 2018 according to the government budget adjustment. The KJRR project is intended for filling the self-sufficiency of RI demand including Mo-99, increasing the NTD capacity and developing technologies related to the research reactor. In project, site investigation is the first activity that defines seismologic and related geologic aspects of the site. Site investigation was carried out from Oct. 2012 to Jan. 2014 and this study is intended to describe detail procedures in locating the reactor core center. The location of the reactor core center was determined by collectively reviewing not only geological information but also information from architects engineering. EL 50m was selected as ground level by levering construction cost. Four recommended locations (R-1a - R-1d) are displayed for the reactor core center. R-1a was found optimal in consideration of medium rock contour, portion of medium rock covering reactor buildings, construction cost, physical protection and electrical resistivity. It is noted that engineering properties of the medium rock is TCR/RQD 100/53, elastic modulus 7,710 - 8,720MPa, permeability coefficient 2.92E-06cm/s, and S-wave velocity 1,380m/s, sound for foundations of reactor buildings.

  16. Breeder reactors

    International Nuclear Information System (INIS)

    Gollion, H.

    1977-01-01

    The reasons for the development of fast reactors are briefly reviewed (a propitious neutron balance oriented towards a maximum uranium burnup) and its special requirements (cooling, fissile material density and reprocessing) discussed. The three stages in the French program of fast reactor development are outlined with Rapsodie at Cadarache, Phenix at Marcoule, and Super Phenix at Creys-Malville. The more specific features of the program of research and development are emphasized: kinetics and the core, the fuel and the components [fr

  17. Nuclear reactor

    International Nuclear Information System (INIS)

    Schulze, I.; Gutscher, E.

    1980-01-01

    The core contains a critical mass of UN or U 2 N 3 in the form of a noncritical solution with melted Sn being kept below a N atmosphere. The lining of the reactor core consists of graphite. If fission progresses part of the melted metal solution is removed and cleaned from fission products. The reactor temperatures lie in the range of 300 to 2000 0 C. (Examples and tables). (RW) [de

  18. Reactor technology

    International Nuclear Information System (INIS)

    Erdoes, P.

    1977-01-01

    This is one of a series of articles discussing aspects of nuclear engineering ranging from a survey of various reactor types for static and mobile use to mention of atomic thermo-electric batteries of atomic thermo-electric batteries for cardiac pacemakers. Various statistics are presented on power generation in Europe and U.S.A. and economics are discussed in some detail. Molten salt reactors and research machines are also described. (G.M.E.)

  19. Reactor containment

    International Nuclear Information System (INIS)

    Kawabe, Ryuhei; Yamaki, Rika.

    1990-01-01

    A water vessel is disposed and the gas phase portion of the water vessel is connected to a reactor container by a pipeline having a valve disposed at the midway thereof. A pipe in communication with external air is extended upwardly from the liquid phase portion to a considerable height so as to resist against the back pressure by a waterhead in the pipeline. Accordingly, when the pressure in the container is reduced to a negative level, air passes through the pipeline and uprises through the liquid phase portion in the water vessel in the form of bubbles and then flows into the reactor container. When the pressure inside of the reactor goes higher, since the liquid surface in the water vessel is forced down, water is pushed up into the pipeline. Since the waterhead pressure of a column of water in the pipeline and the pressure of the reactor container are well-balanced, gases in the reactor container are not leaked to the outside. Further, in a case if a great positive pressure is formed in the reactor container, the inner pressure overcomes the waterhead of the column of water, so that the gases containing radioactive aerosol uprise in the pipeline. Since water and the gases flow being in contact with each other, this can provide the effect of removing aerosol. (T.M.)

  20. Fast reactors

    International Nuclear Information System (INIS)

    Vasile, A.

    2001-01-01

    Fast reactors have capacities to spare uranium natural resources by their breeding property and to propose solutions to the management of radioactive wastes by limiting the inventory of heavy nuclei. This article highlights the role that fast reactors could play for reducing the radiotoxicity of wastes. The conversion of 238 U into 239 Pu by neutron capture is more efficient in fast reactors than in light water reactors. In fast reactors multi-recycling of U + Pu leads to fissioning up to 95% of the initial fuel ( 238 U + 235 U). 2 strategies have been studied to burn actinides: - the multi-recycling of heavy nuclei is made inside the fuel element (homogeneous option); - the unique recycling is made in special irradiation targets placed inside the core or at its surroundings (heterogeneous option). Simulations have shown that, for the same amount of energy produced (400 TWhe), the mass of transuranium elements (Pu + Np + Am + Cm) sent to waste disposal is 60,9 Kg in the homogeneous option and 204.4 Kg in the heterogeneous option. Experimental programs are carried out in Phenix and BOR60 reactors in order to study the feasibility of such strategies. (A.C.)

  1. The first Swedish nuclear reactor - from technical prototype to scientific instrument; Sveriges foersta kaernreaktor - fraan teknisk prototyp till vetenskapligt instrument

    Energy Technology Data Exchange (ETDEWEB)

    Fjaestad, M. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of History of Science and Technology

    2001-01-01

    The first Swedish reactor R1, constructed at the Royal Inst. of Technology in Stockholm, went critical in July 1954. This report presents historical aspects of the reactor, in particular about the reactor as a research instrument and a centre for physical science. The tensions between its role as a prototype and a step in the development of power reactors and that as a scientific instrument are especially focused.

  2. Conflits armés et Environnement : Cadre, modalités, méthodes et rôle de l’Évaluation Environnementale

    Directory of Open Access Journals (Sweden)

    Michel-André Bouchard

    2010-11-01

    Full Text Available Les conflits armés sont source de catastrophes majeures pour l’environnement. Dans les années 60, la défoliation de la jungle vietnamienne par l’armée américaine a interpellé la conscience collective sur la protection de l’environnement en situation de conflit armé (Pearce, 2000. La guerre du Golfe de 1990-1991, avec l’utilisation des armes à l’uranium appauvri et l’incendie des puits de pétrole a fait de la protection de l’environnement lors des conflits armés une préoccupation internationale. Des dispositions juridiques et réglementaires du droit international interdisent et limitent les actions néfastes sur l’environnement en temps de guerre. Au nombre de ces dispositions, il y a la Convention ENMOD de 1976, le Protocole I de Genève de 1977 et les Directives de la Croix-Rouge pour la formation des forces armées (1996. La difficulté de mise en œuvre de ces instruments est l’une des causes principales de l’exacerbation et de la persistance des impacts environnementaux des conflits armés. Un bref aperçu des travaux effectués dans ce domaine montre que cette question est jusque-là abordée sous un angle purement théorique, empirique et descriptif (causes, manifestations et typologies des conflits. Et, contrairement aux autres domaines de connaissances (scientifiques, économistes, juristes, universitaires, les spécialistes de l’évaluation environnementale se sont à ce jour peu intéressés à cette question.L’analyse des impacts environnementaux permet de dresser une typologie axée sur les trois grandes phases de déroulement des conflits armés: pré-conflit, syn-conflit et post-conflit. S’y ajoutent les impacts « collatéraux » qui se poursuivent même pendant la phase post-conflit.L’article analyse l’applicabilité de la procédure d’Evaluation Environnementale (EE et d’Evaluation Environnementale Stratégique (EES en distinguant les différentes phases des conflits armés et en

  3. R-1 (C-620-A) and R-2 (C-620-B) air compressor control logic, computer software description. Revision 1

    International Nuclear Information System (INIS)

    Walter, K.E.

    1995-01-01

    This document provides an updated computer software description for the software used on the FFTF R-1 (C-620-A) and R-2 (C-620-B) air compressor programmable controllers. Logic software design changes were required to allow automatic starting of a compressor that had not been previously started

  4. Pharmacological properties of homomeric and heteromeric GluR1o and GluR3o receptors

    DEFF Research Database (Denmark)

    Nielsen, B S; Banke, T G; Schousboe, A

    1998-01-01

    Homomeric and heteromeric alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptor subunits GluR1o and GluR3o were expressed in Spodoptera frugiperda (Sf9) insect cells. Membranes containing the recombinant receptors showed a doublet of bands of the expected size (99-109 kDa) after...

  5. On the Composition and Neutrix Composition of the Delta Function and the Function cosh^{-1}(|x|^{1/r}+1

    Directory of Open Access Journals (Sweden)

    Brian Fisher

    2017-03-01

    Full Text Available Let $F$ be a distribution in $\\mathcal{D'}$ and let $f$ be a locally summable function. The composition $F(f(x$ of $F$ and $f$ is said to exist and be equal to the distribution $h(x$ if the limit of the sequence $\\{ F_{n}(f(x\\}$ is equal to $h(x$, where $F_n(x =F(x*\\delta _n(x$ for $n=1,2, \\ldots$ and $\\{\\delta_n(x\\}$ is a certain regular sequence converging to the Dirac delta function. It is proved that the neutrix composition $ \\delta^{(s}[\\cosh^{-1} (x_+^{1/r}+1] $ exists and \\beqa \\delta^{(s}[\\cosh^{-1} (x_+^{1/r}+1] = - \\sum _{k=0} ^{M-1} \\sum_{i=0}^{kr+r} {k \\choose i}{(-1^{i+k}rc_{r,s,k} \\over (kr+rk!}\\delta ^{(k}(x, for $s =M-1,M, M+1,\\ldots$ and $r=1,2,\\ldots,$ where $$c_{r,s,k}=\\sum _{j=0}^{i} {i \\choose j}{ (-1^{kr+r-i}(2j-i^{s+1}\\over 2^{s+i+1} },$$ $M$ is the smallest integer for which $s-2r+1 < 2Mr$ and $r\\le s/(2M+2.$ Further results are also proved.

  6. Generation IV reactors: reactor concepts

    International Nuclear Information System (INIS)

    Cardonnier, J.L.; Dumaz, P.; Antoni, O.; Arnoux, P.; Bergeron, A.; Renault, C.; Rimpault, G.; Delpech, M.; Garnier, J.C.; Anzieu, P.; Francois, G.; Lecomte, M.

    2003-01-01

    Liquid metal reactor concept looks promising because of its hard neutron spectrum. Sodium reactors benefit a large feedback experience in Japan and in France. Lead reactors have serious assets concerning safety but they require a great effort in technological research to overcome the corrosion issue and they lack a leader country to develop this innovative technology. In molten salt reactor concept, salt is both the nuclear fuel and the coolant fluid. The high exit temperature of the primary salt (700 Celsius degrees) allows a high energy efficiency (44%). Furthermore molten salts have interesting specificities concerning the transmutation of actinides: they are almost insensitive to irradiation damage, some salts can dissolve large quantities of actinides and they are compatible with most reprocessing processes based on pyro-chemistry. Supercritical water reactor concept is based on operating temperature and pressure conditions that infers water to be beyond its critical point. In this range water gets some useful characteristics: - boiling crisis is no more possible because liquid and vapour phase can not coexist, - a high heat transfer coefficient due to the low thermal conductivity of supercritical water, and - a high global energy efficiency due to the high temperature of water. Gas-cooled fast reactors combining hard neutron spectrum and closed fuel cycle open the way to a high valorization of natural uranium while minimizing ultimate radioactive wastes and proliferation risks. Very high temperature gas-cooled reactor concept is developed in the prospect of producing hydrogen from no-fossil fuels in large scale. This use implies a reactor producing helium over 1000 Celsius degrees. (A.C.)

  7. Research reactors - an overview

    International Nuclear Information System (INIS)

    West, C.D.

    1997-01-01

    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

  8. Identification of potential small molecule allosteric modulator sites on IL-1R1 ectodomain using accelerated conformational sampling method.

    Directory of Open Access Journals (Sweden)

    Chao-Yie Yang

    Full Text Available The interleukin-1 receptor (IL-1R is the founding member of the interleukin 1 receptor family which activates innate immune response by its binding to cytokines. Reports showed dysregulation of cytokine production leads to aberrant immune cells activation which contributes to auto-inflammatory disorders and diseases. Current therapeutic strategies focus on utilizing antibodies or chimeric cytokine biologics. The large protein-protein interaction interface between cytokine receptor and cytokine poses a challenge in identifying binding sites for small molecule inhibitor development. Based on the significant conformational change of IL-1R type 1 (IL-1R1 ectodomain upon binding to different ligands observed in crystal structures, we hypothesized that transient small molecule binding sites may exist when IL-1R1 undergoes conformational transition and thus suitable for inhibitor development. Here, we employed accelerated molecular dynamics (MD simulation to efficiently sample conformational space of IL-1R1 ectodomain. Representative IL-1R1 ectodomain conformations determined from the hierarchy cluster analysis were analyzed by the SiteMap program which leads to identify small molecule binding sites at the protein-protein interaction interface and allosteric modulator locations. The cosolvent mapping analysis using phenol as the probe molecule further confirms the allosteric modulator site as a binding hotspot. Eight highest ranked fragment molecules identified from in silico screening at the modulator site were evaluated by MD simulations. Four of them restricted the IL-1R1 dynamical motion to inactive conformational space. The strategy from this study, subject to in vitro experimental validation, can be useful to identify small molecule compounds targeting the allosteric modulator sites of IL-1R and prevent IL-1R from binding to cytokine by trapping IL-1R in inactive conformations.

  9. Nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Prescott, R F; George, B V; Baglin, C J

    1978-05-10

    Reference is made to thermal insulation on the inner surfaces of containment vessels of fluid cooled nuclear reactors and particularly in situations where the thermal insulation must also serve a structural function and transmit substantial load forces to the surface which it covers. An arrangement is described that meets this requirement and also provides for core support means that favourably influences the flow of hot coolant from the lower end of the core into a plenum space in the hearth of the reactor. The arrangement comprises a course of thermally insulating bricks arranged as a mosaic covering a wall of the reactor and a course of thermally insulating tiles arranged as a mosaic covering the course of bricks. Full constructional details are given.

  10. Nuclear reactors

    International Nuclear Information System (INIS)

    Prescott, R.F.; George, B.V.; Baglin, C.J.

    1978-01-01

    Reference is made to thermal insulation on the inner surfaces of containment vessels of fluid cooled nuclear reactors and particularly in situations where the thermal insulation must also serve a structural function and transmit substantial load forces to the surface which it covers. An arrangement is described that meets this requirement and also provides for core support means that favourably influences the flow of hot coolant from the lower end of the core into a plenum space in the hearth of the reactor. The arrangement comprises a course of thermally insulating bricks arranged as a mosaic covering a wall of the reactor and a course of thermally insulating tiles arranged as a mosaic covering the course of bricks. Full constructional details are given. (UK)

  11. Bioconversion reactor

    Science.gov (United States)

    McCarty, Perry L.; Bachmann, Andre

    1992-01-01

    A bioconversion reactor for the anaerobic fermentation of organic material. The bioconversion reactor comprises a shell enclosing a predetermined volume, an inlet port through which a liquid stream containing organic materials enters the shell, and an outlet port through which the stream exits the shell. A series of vertical and spaced-apart baffles are positioned within the shell to force the stream to flow under and over them as it passes from the inlet to the outlet port. The baffles present a barrier to the microorganisms within the shell causing them to rise and fall within the reactor but to move horizontally at a very slow rate. Treatment detention times of one day or less are possible.

  12. Nuclear reactor

    International Nuclear Information System (INIS)

    Scholz, M.

    1976-01-01

    An improvement of the accessibility of that part of a nuclear reactor serving for biological shield is proposed. It is intended to provide within the biological shield, distributed around the circumference of the reactor pressure vessel, several shielding chambers filled with shielding material, which are isolated gastight from the outside by means of glass panes with a given bursting strength. It is advantageous that, on the one hand, inspection and maintenance will be possible without great effort and, on the other, a large relief cross section will be at desposal if required. (UWI) [de

  13. NEUTRONIC REACTOR

    Science.gov (United States)

    Wigner, E.P.; Weinberg, A.W.; Young, G.J.

    1958-04-15

    A nuclear reactor which uses uranium in the form of elongated tubes as fuel elements and liquid as a coolant is described. Elongated tubular uranium bodies are vertically disposed in an efficient neutron slowing agent, such as graphite, for example, to form a lattice structure which is disposed between upper and lower coolant tanks. Fluid coolant tubes extend through the uranium bodies and communicate with the upper and lower tanks and serve to convey the coolant through the uranium body. The reactor is also provided with means for circulating the cooling fluid through the coolant tanks and coolant tubes, suitable neutron and gnmma ray shields, and control means.

  14. Evaporation rate measurement in the pool of IEAR-1 reactor

    International Nuclear Information System (INIS)

    Torres, Walmir Maximo; Cegalla, Miriam A.; Baptista Filho, Benedito Dias

    2000-01-01

    The surface water evaporation in pool type reactors affects the ventilation system operation and the ambient conditions and dose rates in the operation room. This paper shows the results of evaporation rate experiment in the pool of IEA-R1 research reactor. The experiment is based on the demineralized water mass variation inside cylindrical metallic recipients during a time interval. Other parameters were measured, such as: barometric pressure, relative humidity, environmental temperature, water temperature inside the recipients and water temperature in the reactor pool. The pool level variation due to water contraction/expansion was calculated. (author)

  15. Construction of a high affinity zinc binding site in the metabotropic glutamate receptor mGluR1

    DEFF Research Database (Denmark)

    Jensen, Anders A.; Sheppard, P O; Jensen, L B

    2001-01-01

    a molecular model of the ATD of mGluR1 based on a weak amino acid sequence similarity with a bacterial periplasmic binding protein. The ATD consists of two globular lobes, which are speculated to contract from an "open" to a "closed" conformation following agonist binding. In the present study, we have...... created a Zn(2+) binding site in mGluR1b by mutating the residue Lys(260) to a histidine. Zinc acts as a noncompetitive antagonist of agonist-induced IP accumulation on the K260H mutant with an IC(50) value of 2 microm. Alanine mutations of three potential "zinc coligands" in proximity to the introduced...

  16. Neutronic reactor

    International Nuclear Information System (INIS)

    Wende, C.W.J.

    1976-01-01

    The method of operating a water-cooled neutronic reactor having a graphite moderator is described which comprises flowing a gaseous mixture of carbon dioxide and helium, in which the helium comprises 40--60 volume percent of the mixture, in contact with the graphite moderator. 2 claims, 4 figures

  17. Neutronic reactor

    International Nuclear Information System (INIS)

    Wende, C.W.J.

    1976-01-01

    A safety rod for a nuclear reactor has an inner end portion having a gamma absorption coefficient and neutron capture cross section approximately equal to those of the adjacent shield, a central portion containing materials of high neutron capture cross section and an outer end portion having a gamma absorption coefficient at least equal to that of the adjacent shield

  18. Reactor facility

    International Nuclear Information System (INIS)

    Suzuki, Hiroaki; Murase, Michio; Yokomizo, Osamu.

    1997-01-01

    The present invention provides a BWR type reactor facility capable of suppressing the amount of steams generated by the mutual effect of a failed reactor core and coolants upon occurrence of an imaginal accident, and not requiring spacial countermeasures for enhancing the pressure resistance of the container vessel. Namely, a means for supplying cooling water at a temperature not lower by 30degC than the saturated temperature corresponding to the inner pressure of the containing vessel upon occurrence of an accident is disposed to a lower dry well below the pressure vessel. As a result, upon occurrence of such an accident that the reactor core should be melted and flown downward of the pressure vessel, when cooling water at a temperature not lower than the saturated temperature, for example, cooling water at 100degC or higher is supplied to the lower dry well, abrupt generation of steams by the mutual effect of the failed reactor core and cooling water is scarcely caused compared with a case of supplying cooling water at a temperature lower than the saturation temperature by 30degC or more. Accordingly, the amount of steams to be generated can be suppressed, and special countermeasure is no more necessary for enhancing the pressure resistance of the container vessel is no more necessary. (I.S.)

  19. Nuclear reactor

    International Nuclear Information System (INIS)

    Gilroy, J.E.

    1980-01-01

    An improved cover structure for liquid metal cooled fast breeder type reactors is described which it is claimed reduces the temperature differential across the intermediate grid plate of the core cover structure and thereby reduces its subjection to thermal stresses. (UK)

  20. Reactor licensing

    International Nuclear Information System (INIS)

    Harvie, J.D.

    2002-01-01

    This presentation discusses reactor licensing and includes the legislative basis for licensing, other relevant legislation , the purpose of the Nuclear Safety and Control Act, important regulations, regulatory document, policies, and standards. It also discusses the role of the CNSC, its mandate and safety philosophy

  1. Nuclear reactor

    International Nuclear Information System (INIS)

    Hattori, Sadao; Sekine, Katsuhisa.

    1987-01-01

    Purpose: To decrease the thickness of a reactor container and reduce the height and the height and plate thickness of a roof slab without using mechanical vibration stoppers. Constitution: Earthquake proofness is improved by filling fluids such as liquid metal between a reactor container and a secondary container and connecting the outer surface of the reactor container with the inner surface of the secondary container by means of bellows. That is, for the horizontal seismic vibrations, horizontal loads can be supported by the secondary container without providing mechanical vibration stoppers to the reactor container and the wall thickness can be reduced thereby enabling to simplify thermal insulation structure for the reduction of thermal stresses. Further, for the vertical seismic vibrations, verical loads can be transmitted to the secondary container thereby enabling to reduce the wall thickness in the same manner as for the horizontal load. By the effect of transferring the point of action of the container load applied to the roof slab to the outer circumferential portion, the intended purpose can be attained and, in addition, the radiation dose rate at the upper surface of the roof slab can be decreased. (Kamimura, M.)

  2. Reactor system

    International Nuclear Information System (INIS)

    Miyano, Hiroshi; Narabayashi, Naoshi.

    1990-01-01

    The represent invention concerns a reactor system with improved water injection means to a pressure vessel of a BWR type reactor. A steam pump is connected to a heat removing system pipeline, a high pressure water injection system pipeline and a low pressure water injection system pipeline for injecting water into the pressure vessel. A pump actuation pipeline is disposed being branched from a main steam pump or a steam relieaf pipeline system, through which steams are supplied to actuate the steam pump and supply cooling water into the pressure vessel thereby cooling the reactor core. The steam pump converts the heat energy into the kinetic energy and elevates the pressure of water to a level higher than the pressure of the steams supplied by way of a pressure-elevating diffuser. Cooling water can be supplied to the pressure vessel by the pressure elevation. This can surely inject cooling water into the pressure vessel upon loss of coolant accident or in a case if reactor scram is necessary, without using an additional power source. (I.N.)

  3. Reactor core

    International Nuclear Information System (INIS)

    Matsuura, Tetsuaki; Nomura, Teiji; Tokunaga, Kensuke; Okuda, Shin-ichi

    1990-01-01

    Fuel assemblies in the portions where the gradient of fast neutron fluxes between two opposing faces of a channel box is great are kept loaded at the outermost peripheral position of the reactor core also in the second operation cycle in the order to prevent interference between a control rod and the channel box due to bending deformation of the channel box. Further, the fuel assemblies in the second row from the outer most periphery in the first operation cycle are also kept loaded at the second row in the second operation cycle. Since the gradient of the fast neutrons in the reactor core is especially great at the outer circumference of the reactor core, the channel box at the outer circumference is bent such that the surface facing to the center of the reactor core is convexed and the channel box in the second row is also bent to the identical direction, the insertion of the control rod is not interfered. Further, if the positions for the fuels at the outermost periphery and the fuels in the second row are not altered in the second operation cycle, the gaps are not reduced to prevent the interference between the control rod and the channel box. (N.H.)

  4. Amino methylation of 2-R-6-R_1-imidazo-[2.1-B]-1.3.4-thiadiazole

    International Nuclear Information System (INIS)

    Saidov, D.K.; Rakhmonov, R.O.; Khodzhiboev, Yu.; Kukaniev, M.A.; Bandaev, S.

    2015-01-01

    Present article is devoted to amino methylation of 2-R-6-R_1-imidazo-[2.1-B]-1.3.4-thiadiazole. The reaction of new modifications of derivatives of imidazo-[2.1-B]-1.3.4-thiadiazoles-2-bromine-6-p-bromophenyl and 2-alkyl alkylene sulfonyl-6-phenyl imidazo--[2.1-B]-1.3.4-thiadiazole on Mannich with secondary and heterocyclic amines was studied.

  5. New about research reactors

    International Nuclear Information System (INIS)

    Egorenkov, P.M.

    2001-01-01

    The multi-purpose research reactor MAPLE (Canada) and concept of new reactor MAPLE-CNF as will substitute the known Canadian research reactor NRU are described. New reactor will be used as contributor for investigations into materials, neutron beams and further developments for the CANDU type reactor. The Budapest research reactor (BRR) and its application after the last reconstruction are considered also [ru

  6. Simulation study of the photon quality correction factors of ionization chambers for FiR 1 epithermal neutron beam

    International Nuclear Information System (INIS)

    Koivunoro, H.; Uusi-Simola, J.; Savolainen, S.; Kotiluoto, P.; Auterinen, I.; Kosunen, A.

    2006-01-01

    At FiR 1 BNCT facility in Finland, neutron-insensitive Mg(Ar) ionization chambers are used for photon dose measurements in an epithermal neutron beam. Previously, photon sensitivity factors for the chamber for the measurements in a water phantom in FiR 1 beam have been determined experimentally from measurements in 60 Co gamma and in a 6 MV clinical accelerator photon beams. However, the response of the ionization chamber in a water phantom depends on energy spectrum and angle of the photons and the secondary electrons created inside the phantom and may differ depending on type of the irradiation source (accelerator vs. an epithermal neutron beam). Also, the experimental sensitivity factor does not take into account the possible perturbations in the photon production in phantom caused by the ionization chamber materials. Therefore, it is necessary to determine the photon quality correction factors (k Qγ ) for the Mg(Ar) chamber at the FiR 1 beam through computer simulations. In this study, the k Qγ factors have been determined for Mg(Ar) chamber from Monte Carlo calculations of absorbed photon dose at two depths in a water phantom using MCNP code. The k qγ factors obtained with this method are compared to the sensitivity factors determined with measurements in an accelerator photon beam and to the k Qγ factors published previously. (author)

  7. Effect of Formic Acid on Exopolysaccharide Production in Skim Milk Fermentation by Lactobacillus delbrueckii subsp. bulgaricus OLL1073R-1.

    Science.gov (United States)

    Nishimura, Junko; Kawai, Yasushi; Aritomo, Ryota; Ito, Yoshiyuki; Makino, Seiya; Ikegami, Shuji; Isogai, Emiko; Saito, Tadao

    2013-01-01

    In yogurt, the formation of formate by Streptococcus thermophilus stimulates the activity of Lactobacillus delbrueckii subsp. bulgaricus (L. bulgaricus). However, there have been no reports how formic acid acts on the exopolysaccharide (EPS) production of L. bulgaricus. Here, the effect of formate on the EPS production in skim milk by L. bulgaricus OLL1073R-1 was investigated. After incubation for 24 hr with 100 mg/l formate, cell proliferation and lactic acid production were accelerated. The viable and total cell numbers were increased about ten- and four-fold, respectively. The amount of EPS in culture with formate (~116 µg/ml) was also four-fold greater than that of the control (~27 µg/ml). Although elongation of cells was observed at 6 hr of cultivation in both cultures, cells cultivated with formate returned to a normal shape after incubation for 24 hr. The sensitivity to cell wall hydrolase and composition of surface layer proteins, as well as the cell membrane fatty acid composition of L. bulgaricus OLL1073R-1, were not influenced by formate. However, differences were observed in intracellular fatty acid compositions and sensitivity to antibiotics. Cell length and surface damage returned to normal in cultures with formate. These observations suggest that formic acid is necessary for normal cell growth of L. bulgaricus OLL1073R-1 and higher EPS production.

  8. Impaired IFNγ-Signaling and Mycobacterial Clearance in IFNγR1-Deficient Human iPSC-Derived Macrophages

    Directory of Open Access Journals (Sweden)

    Anna-Lena Neehus

    2018-01-01

    Full Text Available Mendelian susceptibility to mycobacterial disease (MSMD is caused by inborn errors of interferon gamma (IFNγ immunity and is characterized by severe infections by weakly virulent mycobacteria. Although IFNγ is the macrophage-activating factor, macrophages from these patients have never been studied. We demonstrate the generation of heterozygous and compound heterozygous (iMSMD-cohet induced pluripotent stem cells (iPSCs from a single chimeric patient, who suffered from complete autosomal recessive IFNγR1 deficiency and received bone-marrow transplantation. Loss of IFNγR1 expression had no influence on the macrophage differentiation potential of patient-specific iPSCs. In contrast, lack of IFNγR1 in iMSMD-cohet macrophages abolished IFNγ-dependent phosphorylation of STAT1 and induction of IFNγ-downstream targets such as IRF-1, SOCS-3, and IDO. As a consequence, iMSMD-cohet macrophages show impaired upregulation of HLA-DR and reduced intracellular killing of Bacillus Calmette-Guérin. We provide a disease-modeling platform that might be suited to investigate novel treatment options for MSMD and to gain insights into IFNγ signaling in macrophages.

  9. The internal Cdc20 binding site in BubR1 facilitates both spindle assembly checkpoint signalling and silencing

    DEFF Research Database (Denmark)

    Lischetti, Tiziana; Zhang, Gang; Sedgwick, Garry G

    2014-01-01

    Improperly attached kinetochores activate the spindle assembly checkpoint (SAC) and by an unknown mechanism catalyse the binding of two checkpoint proteins, Mad2 and BubR1, to Cdc20 forming the mitotic checkpoint complex (MCC). Here, to address the functional role of Cdc20 kinetochore localization...... in the SAC, we delineate the molecular details of its interaction with kinetochores. We find that BubR1 recruits the bulk of Cdc20 to kinetochores through its internal Cdc20 binding domain (IC20BD). We show that preventing Cdc20 kinetochore localization by removal of the IC20BD has a limited effect...... on the SAC because the IC20BD is also required for efficient SAC silencing. Indeed, the IC20BD can disrupt the MCC providing a mechanism for its role in SAC silencing. We thus uncover an unexpected dual function of the second Cdc20 binding site in BubR1 in promoting both efficient SAC signalling and SAC...

  10. Uptake and incorporation of labeled tryptophan isomers into IAA in the jsR1 mutant of Lemna gibba

    International Nuclear Information System (INIS)

    Baldi, B.G.; Maher, B.R.; Cohen, J.D.

    1989-01-01

    Analyses of the IAA-overproducing mutant of Lemna have been initiated in order to study in vivo biosynthesis of IAA. Using radiolabelled tryptophan isomers prepared from commercial sources of 14 C-D,L tryptophan by chiral separation kinetics of uptake of L and D tryptophan were determined for sterile cultures of individual jsR 1 four-frond colonies. Over a 24 h period, about 50% of the radioactivity from 14 C-L-TRP in media, or about 25% from 14 C-D-TRP, was found in the plant tissue. Maximal rates of uptake were seen in the first six hors for both isomers. Endogenous levels of tryptophan determined in jsR 1 as measures of pool sizes in vivo show 5 to 10 ug/g FW total tryptophan with less than 1% in the D isomer form. Information on uptake and endogenous pool sizes of tryptophan isomers is being used for feeding of stable isotope labeled tryptophan ( 13 C, 14 N) to jsR 1 at physiological levels. Analyses of incorporation of label into IAA using GC-MS and high resolution mass spectrometry are currently underway

  11. Impaired IFNγ-Signaling and Mycobacterial Clearance in IFNγR1-Deficient Human iPSC-Derived Macrophages.

    Science.gov (United States)

    Neehus, Anna-Lena; Lam, Jenny; Haake, Kathrin; Merkert, Sylvia; Schmidt, Nico; Mucci, Adele; Ackermann, Mania; Schubert, Madline; Happle, Christine; Kühnel, Mark Philipp; Blank, Patrick; Philipp, Friederike; Goethe, Ralph; Jonigk, Danny; Martin, Ulrich; Kalinke, Ulrich; Baumann, Ulrich; Schambach, Axel; Roesler, Joachim; Lachmann, Nico

    2018-01-09

    Mendelian susceptibility to mycobacterial disease (MSMD) is caused by inborn errors of interferon gamma (IFNγ) immunity and is characterized by severe infections by weakly virulent mycobacteria. Although IFNγ is the macrophage-activating factor, macrophages from these patients have never been studied. We demonstrate the generation of heterozygous and compound heterozygous (iMSMD-cohet) induced pluripotent stem cells (iPSCs) from a single chimeric patient, who suffered from complete autosomal recessive IFNγR1 deficiency and received bone-marrow transplantation. Loss of IFNγR1 expression had no influence on the macrophage differentiation potential of patient-specific iPSCs. In contrast, lack of IFNγR1 in iMSMD-cohet macrophages abolished IFNγ-dependent phosphorylation of STAT1 and induction of IFNγ-downstream targets such as IRF-1, SOCS-3, and IDO. As a consequence, iMSMD-cohet macrophages show impaired upregulation of HLA-DR and reduced intracellular killing of Bacillus Calmette-Guérin. We provide a disease-modeling platform that might be suited to investigate novel treatment options for MSMD and to gain insights into IFNγ signaling in macrophages. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  12. Polymorphisms of ST2-IL18R1-IL18RAP gene cluster: a new risk for autoimmune thyroid diseases.

    Science.gov (United States)

    Wang, X; Zhu, Y F; Li, D M; Qin, Q; Wang, Q; Muhali, F S; Jiang, W J; Zhang, J A

    2016-02-01

    Interleukin 33 (IL33) / ST2 pathway and ST2-interlukin18 receptor1-interlukin18 receptor accessory protein (ST2-IL18R1-IL18RAP) gene cluster have been involved in many autoimmune diseases but few report in autoimmune thyroid diseases (AITD). In this study, we investigated whether polymorphisms of IL33, ST2, IL18R1, and IL18RAP are associated with Graves' disease (GD) and Hashimoto's thyroiditis (HT), two major forms of AITD, among a Chinese population. A total of 11 SNPs were explored in a case-control study including 417 patients with GD, 250 HT patients and 301 controls, including rs1929992, rs10975519, rs10208293, rs6543116, rs1041973, rs3732127, rs11465597, rs1035130, rs2293225, rs1035127, rs917997 of IL 33, ST2-IL18R1-IL18RAP gene cluster. Genotyping of these SNPs was performed using matrix-assisted laser desorption / ionization-time-of-flight mass spectrometer (MALDI-TOF-MS) platform from Sequenom. The frequencies of allele A and AA+AG genotype of rs6543116 (ST2) in HT patients were significantly increased compared with those of the controls (P = 0.029/0.021, OR = 1.31/1.62). And in another SNP rs917997, AA+AG genotype presented an increased frequency in HT subjects compared with controls (P = 0.046, OR = 1.53). Furthermore, the haplotype GAGCCCG from ST2-IL18R1-IL18RAP gene cluster (rs6543116, rs1041973, rs1035130, rs3732127, rs1035127, rs2293225, rs917997) was associated with increased susceptibility to GD with an OR of 2.03 (P = 0.022, 95% CI = 1.07-3.86). Some SNPs of ST2-IL18R1-IL18RAP gene cluster might increase the risk of susceptibility of HT and GD in Chinese Han population. © 2015 John Wiley & Sons Ltd.

  13. Study of the viability of the production of lutetium - 177 in the nuclear reactor IEA-R1 at IPEN/CNEN-SP

    International Nuclear Information System (INIS)

    Silva, Giovana Pasqualini da

    2008-01-01

    The - emitter 177 Lu is a promising therapeutic radioisotope for the curative treatment of cancer using labelled proteins. It has a half - life of 6.71 day and maximum and average (3 energies of 421 and 133 keV, respectively, resulting in a short range of irradiation of tissue. The decay is accompanied by the emission of low energy -radiation of 208.3 keV (11%) and 113 keV (6.4%), suitable for simultaneous imaging. Lu can be produced by two different routes, namely, by irradiation of natural Lu 2 O 3 target ( 176 Lu, 2.6%) or enriched (in 176 Lu) Lu 2 O 3 target, and also by irradiation of Yb target (Yb 2 O 3 ) followed by radiochemical separation of Lu from Yb isotopes. The objective of this work is the development of a method of the production of 177 Lu through of the (n, gamma) nuclear reaction, by the direct and indirect method of production. Targets of lutetium oxide and ytterbium oxide were irradiated for evaluation of the activity produced and the chemical separation of lutetium and ytterbium was studied using different ion exchange resins. For the direct method, the best results were obtained using the target Lu 2 O 3 enriched in 39.6%. The best results for the indirect method were achieved with the process of separation using 0.25M - HlBA as eluent. The results showed that it is possible to produce 177 Lu of low specific activity for labeling molecules used for bone pain relief and in radiosynoviortesy. (author)

  14. Utilization of plastic detector for pool water radioactivity control of IEA-R1 reactor. Examination of fuel element irradiation behaviour fabricated at IPEN/CNEN-SP

    International Nuclear Information System (INIS)

    Berretta, J.R.; Mesquita, C.H. de; Madi Filho, T.

    1989-01-01

    For the examination of fuel element irradiation behavior that were fabricated at IPEN/CNEN/SP Metalurgical Departament, it was provided a detection system for pool water radioactivity measurements. This system uses a plastic scintillator detector produced at IPEN/CNEN-SP Health Physics Department, with dimensions and shape apropriated for such work. The detection system shows a sensibility of 4.125x10 -2 dps/cm 3 and 20% of efficiency for 131 I radiations. (author) [pt

  15. Role of Caspase-3 Cleaved IP3R1 on Ca2+ Homeostasis and Developmental Competence of Mouse Oocytes and Eggs

    Science.gov (United States)

    Zhang, Nan; Fissore, Rafael. A.

    2014-01-01

    Apoptosis in most cell types is accompanied by altered Ca2+ homeostasis. During apoptosis, caspase-3 mediated cleavage of the type 1 inositol 1,4,5-trisphosphate receptor (IP3R1) generates a 95-kDa C-terminal fragment (C-IP3R1), which represents the channel domain of the receptor. Aged mouse eggs display abnormal Ca2+ homeostasis and express C-IP3R1, although whether or not C-IP3R1 expression contributes to Ca2+ misregulation or a decrease in developmental competency is unknown. We sought to answer these questions by injecting in mouse oocytes and eggs cRNAs encoding CIP3R1. We found that: 1) expression of C-IP3R1 in eggs lowered the Ca2+ content of the endoplasmic reticulum (ER), although, as C-IP3R1 is quickly degraded at this stage, its expression did not impair pre-implantation embryo development; 2) expression of CIP3R1 in eggs enhanced fragmentation associated with aging; 3) endogenous IP3R1 is required for aging associated apoptosis, as its down-regulation prevented fragmentation, and expression of C-IP3R1 in eggs with downregulated IP3R1 partly restored fragmentation; 4) C-IP3R1 expression in GV oocytes resulted in persistent levels of protein, which abolished the increase in the ER releasable Ca2+ pool that occurs during maturation, undermined the Ca2+ oscillatory ability of matured eggs and their activation potential. Collectively, this study supports a role for IP3R1 and C-IP3R1 in regulating Ca2+ homeostasis and the ER Ca2+ content during oocyte maturation. Nevertheless, the role of C-IP3R1 on Ca2+ homeostasis in aged eggs seems minor, as in MII eggs the majority of endogenous IP3R1 remains intact and C-IP3R1 undergoes rapid turnover. PMID:24692207

  16. Reactor core of nuclear reactor

    International Nuclear Information System (INIS)

    Sasagawa, Masaru; Masuda, Hiroyuki; Mogi, Toshihiko; Kanazawa, Nobuhiro.

    1994-01-01

    In a reactor core, a fuel inventory at an outer peripheral region is made smaller than that at a central region. Fuel assemblies comprising a small number of large-diameter fuel rods are used at the central region and fuel assemblies comprising a great number of smalldiameter fuel rods are used at the outer peripheral region. Since a burning degradation rate of the fuels at the outer peripheral region can be increased, the burning degradation rate at the infinite multiplication factor of fuels at the outer region can substantially be made identical with that of the fuels in the inner region. As a result, the power distribution in the direction of the reactor core can be flattened throughout the entire period of the burning cycle. Further, it is also possible to make the degradation rate of fuels at the outer region substantially identical with that of fuels at the inner side. A power peak formed at the outer circumferential portion of the reactor core of advanced burning can be lowered to improve the fuel integrity, and also improve the reactor safety and operation efficiency. (N.H.)

  17. Synthesis, physical-chemical properties, antimicrobial and antifungal activity of some 2-(2-((5-(adamantane-1-yl-4-R-1,2,4-triazole-3-ylthioacetyl-N-R1–hydrazine-carbothioamides

    Directory of Open Access Journals (Sweden)

    V. M. Odyntsova

    2017-12-01

    Full Text Available Special attention of pharmaceutical scientists is attracted to the creation of new potential substances. They select natural heterocyclic molecules that exhibit various types of pharmacological activity as basic structures. Adamantane derivatives, as well as a number of other framework compounds, in the vast majority are biologically active substances. This fact causes interest to the given classes of organic compounds as potential sources for the development of new drugs. Due to the high pharmacological action of 1,2,4-triazole derivatives, the combination of adamantane and 1,2,4-triazole in one molecule can lead to the formation of high-level pharmacological substances. The aim of this work is the synthesis of some 2- (2 - ((5- (adamantane-1-yl -4-R-1,2,4-triasole-3-yl thio acetyl -N-R1-hydrazine-carbothioamides, study of their physical and chemical properties, antimicrobial and antifungal activity. Materials and methods. The chemical names of the compounds are given in accordance with the requirements of the IUPAC nomenclature (1979 and the recommendations of the IUPAC (1993. Study of the physical and chemical properties of 2-(2-((5-(adamantane-1-yl-4-R-1,2,4-triazole-3-ylthioacetyl-N-R1-hydrazine-carbothioamides have been carried out on the certified and licensed equipment in the ZSMU physical-chemical laboratories. The melting temperature was determined by an open capillary method on the Opti Melt MPA 100. The elemental composition of the synthesized compounds was determined on the universal analyzer Elementar Vario L cube (CHNS (standard – sulfanilamide. 1H NMR spectra were recorded on a spectrometer Varian Mercury VX-200 (1H, 200 MHz in dimethylsulfoxide-d6solvent (tetramethylsilane - internal standard and are decoded using ADVASP(tmAnalyzer program (Umatek International Inc.. Chromatographic mass spectral studies were performed on a gas-liquid chromatograph Agilent 1260 Infinity HPLC equipped with an Agilent 6120 mass spectrometer

  18. BubR1 Acts as a Promoter in Cellular Motility of Human Oral Squamous Cancer Cells through Regulating MMP-2 and MMP-9

    Directory of Open Access Journals (Sweden)

    Chou-Kit Chou

    2015-07-01

    Full Text Available BubR1 is a critical component of spindle assembly checkpoint, ensuring proper chromatin segregation during mitosis. Recent studies showed that BubR1 was overexpressed in many cancer cells, including oral squamous cell carcinomas (OSCC. However, the effect of BubR1 on metastasis of OSCC remains unclear. This study aimed to unravel the role of BubR1 in the progression of OSCC and confirm the expression of BubR1 in a panel of malignant OSCC cell lines with different invasive abilities. The results of quantitative real-time PCR showed that the mRNA level of BubR1 was markedly increased in four OSCC cell lines, Ca9-22, HSC3, SCC9 and Cal-27 cells, compared to two normal cells, normal human oral keratinocytes (HOK and human gingival fibroblasts (HGF. Moreover, the expression of BubR1 in these four OSCC cell lines was positively correlated with their motility. Immunofluorescence revealed that BubR1 was mostly localized in the cytosol of human gingival carcinoma Ca9-22 cells. BubR1 knockdown significantly decreased cellular invasion but slightly affect cellular proliferation on both Ca9-22 and Cal-27 cells. Consistently, the activities of metastasis-associated metalloproteinases MMP-2 and MMP-9 were attenuated in BubR1 knockdown Ca9-22 cells, suggesting the role of BubR1 in promotion of OSCC migration. Our present study defines an alternative pathway in promoting metastasis of OSCC cells, and the expression of BubR1 could be a prognostic index in OSCC patients.

  19. Nuclear reactor

    International Nuclear Information System (INIS)

    Gibbons, J.F.; McLaughlin, D.J.

    1978-01-01

    In the pressure vessel of the water-cooled nuclear reactor there is provided an internal flange on which the one- or two-part core barrel is hanging by means of an external flange. A cylinder is extending from the reactor vessel closure downwards to a seat on the core cupport structure and serves as compression element for the transmission of the clamping load from the closure head to the core barrel (upper guide structure). With the core barrel, subject to tensile stress, between the vessel internal flange and its seat on one hand and the compression of the cylinder resp. hold-down element between the closure head and the seat on the other a very strong, elastic sprung structure is obtained. (DG) [de

  20. Nuclear reactor

    International Nuclear Information System (INIS)

    Sasaki, Tomozo.

    1987-01-01

    Purpose: To improve the nuclear reactor availability by enabling to continuously exchange fuels in the natural-slightly enriched uranium region during operation. Constitution: A control rod is withdrawn to the midway of a highly enriched uranium region by means of control rod drives and the highly enriched uranium region is burnt to maintain the nuclear reactor always at a critical state. At the same time, fresh uranium-slightly enriched uranium is continuously supplied gravitationally from a fresh fuel reservoir through fuel reservoir to each of fuel pipes in the natural-slightly enriched uranium region. Then, spent fuels reduced with the reactivity by the burn up are successively taken out from the bottom of each of the fuel pipes through an exit duct and a solenoid valve to the inside of a spent fuel reservoir and the burn up in the natural-slightly enriched uranium region is conducted continuously. (Kawakami, Y.)