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Sample records for bohunice v-1 reactor

  1. Preliminary results of scoop samples analysis from reactor pressure vessels of Bohunice V-1 NPP

    International Nuclear Information System (INIS)

    Kupca, L.

    1997-01-01

    In the paper are presented the main goals and results from the scoop specimen analysis performed on the both RPVs WWER-440/230 in Jaslovske Bohunice V-1 NPPs. Main tasks of this complex activity were: model experiments for analysis procedures optimisation; chemical analysis; hardness measurements on the RPV and bulk samples; microstructure analysis; scanning electron microscope and microprobe analysis; gamma spectrometry; brittle fracture temperature evaluation; trends of brittle fracture temperature growth after annealing procedure. In conclusions and recommendations are discussed the planned activities in the field of both RPVs integrity evaluation for the future operation of the NPP Jaslovske Bohunice V-1. (author)

  2. Bohunice V1 NPP upgrading programme

    International Nuclear Information System (INIS)

    Kerak, J.

    2001-01-01

    The paper describes whole process of Bohunice V1 NPP nuclear safety and operational reliability level increase which has been performed since units commissioning (1. unit in 1978, 2. unit in 1980), continued Small Reconstruction (1991 -1993) and finished Gradual Upgrading(1994 -2000). The main purpose is to last stage -Gradual upgrading of Bohunice V1 NPP. (author)

  3. Safety upgrading of Bohunice V1 NPP

    International Nuclear Information System (INIS)

    2001-01-01

    This CD is multimedia presentation of programme safety upgrading of Bohunice V1 NPP. It consist of next chapters: (1) Introductory speeches; (2) Nuclear power plant WWER 440; (3) Safety improvement; (4) Bohunice Nuclear power plants subsidiary; (5) Siemens; (6) REKON; (7) VUJE Trnava, Inc. - Engineering, Design and Research Organisation; (8) Album

  4. Experience of Bohunice V-1 NPP

    International Nuclear Information System (INIS)

    Dobik, Dobroslav

    2000-01-01

    Slovakia remains significantly dependent on imports of primary energy sources, which represent as much as 80% of the demand. Of the total consumption of electricity in Slovakia, 40% was generated in nuclear power plant units in 1998. Slovakia operates 6 units with WWER 440 nuclear reactors. Slovakia is the signatory of all important international agreements and conventions in the field of nuclear energy, and its legislation is in an advanced stage of approximation to European Union law. This is a very important aspect, showing Slovakia's approach to nuclear safety. In 1993 Slovakia accepted the commitments of the UN Convention on Climate Changes, including a reduction of greenhouse gases to 1990 levels by the year 2000. Moreover, as an internal target Slovakia has set the reaching of the 'Toronto Objective', i.e. 20% reduction in CO x , emissions through the year 2005 as compared to 1988. In our opinion, this is not possible without nuclear energy. Time has shown, that the political aspects are more powerful, especially if you underestimate their importance over the than the technical ones. In the case of Bohunice V-1 NPP the political aspects were on the following levels: 1. Slovak republic (Czechoslovakia), political changes, decisions of the government; 2. European Union - Agenda 2000, Accession criteria, nuclear safety criteria, EBRD; 3. Austria as a neighbouring country. Starting with year 1990, 23 expert missions took place at Bohunice V-1 NPP by now. The only criteria for further operation should have been Nuclear safety, which is supervised by NRA SR. It was fully in compliance with EU policy, each country is solely responsible for its energy sector and for nuclear energy use. Our satisfaction lasted not too long. Following negotiation with EU on the highest political level, driven by willingness to be invited for negotiation of accession on the Helsinki Summit, the Slovak government decided on September 14th, on Bohunice V-1 Units shutdown in 2006 and 2008

  5. Backfitting of Nuclear Power Plant Bohunice V1 in Slovakia

    International Nuclear Information System (INIS)

    Ferenc, M.

    1999-01-01

    Nuclear power plants in the Slovak Republic generate almost 55 % of electricity. The operating organization and the Nuclear Regulatory Authority of the Slovak Republic pay a great attention to safe and reliable operation of four units with VVER 440 reactors at Bohunices site and one in Mochovce side. Engineering and design organizations in cooperation with well known international companies prepare evaluation of safety conditions, safety analyses and projects for the implementation of modifications to upgrade the nuclear safety of the units in operation. A gradual safety upgrading (reconstruction) of the V-1 Bohunice plant has been in progress, a modernization of the V-2 Bohunice plant is being prepared. Simultaneously the commissioning of Unit 2 at the Mochovce plant is being implemented.(author)

  6. Experience from replacement and check of thermocouples during reconstruction of in-reactor temperature measurements at Bohunice V-1 units 1 and 2

    International Nuclear Information System (INIS)

    Slanina, M.; Stanc, J.

    2001-01-01

    Replacement of thermocouples in the protection tube blocks was a key phase of the reconstruction of in-reactor temperature measurements at Bohunice V-1 with regard to the success, reliability and impact on safety of unit operation. The replacement consisted of reliable and safe withdrawal of 216 old thermocouples, their disposal and installation of new thermocouples into dry channels. In the material presented, this phase of reconstruction is described in details, with focus on the evaluation of replacement quality and check activities carried out at the new installed thermocouples. (Authors)

  7. Bohunice V-1. Review of safety upgrading and operating experiences

    International Nuclear Information System (INIS)

    Korec, J.; Kuschel, D.

    2000-01-01

    The Bohunice site in the Slovak Republic has two Russian-designed twin-unit nuclear power plants, one equipped with reactors of the WWER 440/230 type, the other with type WWER 440/213 reactors. Two older units (V-1) started commercial operation in late 1978 and 1980 respectively and have been supplying electricity to the national grid since that time without any events that could have degraded plant safety level. In the period prior to 1990 the utility Slovenske Elektrarne (S.E.) performed extensive modifications and upgrades to the original design of the two older units V-1 NPP. Furthermore, significant steps in safety improvement for Bohunice NPP V-1 have been made since 1990. Following the political restructuring of the former Czechoslovakia and the country's new open-door policy towards western organizations, several international expert missions were focused on evaluation of Bohunice NPP safety status level and operational reliability, particularly targeting the two older units. Based on recommendations of individual expert missions and complementary deterministic and probabilistic safety analyses performed by S.E., the Czechoslovak Nuclear Regulatory Authority issued the Resolution No. 5/91 defining 81 measures concerning further safety and reliability improvement of Bohunice V1 .A range of short-term and long-term upgrades was prioritised in terms of importance to plant safety and work to implement these measures commenced in the early nineties. During the 'Small Reconstruction' from 1991 to 1993 some of the short term upgrading measures were realized to eliminate the most serious safety deficits, thus to achieve a significant reduction in core damage frequency and a major improvement in confinement integrity. In this paper and presentation the goals of the gradual reconstruction project, basic engineering, detailed engineering and realization, last major stage of Unit 2 upgrade, as well as final stage of Unit 1 upgrade in early 2000 are presented

  8. Seismic re-evaluation criteria for Bohunice V1 reconstruction

    International Nuclear Information System (INIS)

    Campbell, R.; Schlund, H.; Warnken, L.

    2001-01-01

    Bohunice V1 in Slovakia is a Russian designed two unit WWER 440, Model 230 Pressurized Water Reactor. The plant was not originally designed for earthquake. Subsequent and ongoing reassessments now confirm that the seismic hazard at the site is significant. EBO, the plant owner has contracted with a consortium lead by Siemens AG (REKON) to do major reconstruction of the plant to significantly enhance its safety systems by the addition of new systems and the upgrading of existing systems. As part of the reconstruction, a complete seismic assessment and upgrading is required for existing safety relevant structures, systems and components. It is not practical to conduct this reassessment and upgrading using criteria applied to new design of nuclear power plants. Alternate criteria may be used to achieve adequate safety goals. Utilities in the U.S. have faced several seismic issues with operating NPPs and to resolve these issues, alternate criteria have been developed which are much more cost effective than use of criteria for new design. These alternate criteria incorporate the knowledge obtained from investigation of the performance of equipment in major earthquakes and include provisions for structures and passive equipment to deform beyond the yield point, yet still provide their essential function. IAEA has incorporated features of these alternate criteria into draft Technical Guidelines for application to Bohunice V1 and V2. REKON has developed plant specific criteria and procedures for the Bohunice V1 reconstruction that incorporate major features of the U.S. developed alternate criteria, comply to local codes and which envelop the draft IAEA Technical Guidelines. Included in these criteria and procedures are comprehensive walkdown screening criteria for equipment, piping, HVAC and cable raceways, analytical criteria which include inelastic energy absorption factors defined on an element basis and testing criteria which include specific guidance on interpretation

  9. REKO - Bohunice V-1. Experience with instrumentation and control system

    International Nuclear Information System (INIS)

    Arbet, L.; Ziska, D.; Golan, P.; Karaba, P.; Krupa, S.; Wiening, K.-H.

    2000-01-01

    In this paper and in presentation some results of upgrading of the NPP Bohunice V-1 are presented. For the first time, extensive upgrades are performed in all safety-related areas of both units with VVER 440/230 reactors. These upgrades focused on: - Expansion and upgrading of the process safety systems; - Replacement of the safety I and C system with a TELEPERM XS-based system; - Spatial separation of safety equipment; - Modernisation of the electrical auxiliary power systems; - Seismic upgrading and fire protection; - Improvement of the man-machine interface. This upgrade is considered exemplary around the world. The most extensive stage of gradual reconstruction of Unit 2 was completed according to the schedule in January 1999. For the first time, a reactor which incorporates state-of-the-art digital I and C in its reactor protection system is on-line. (author)

  10. The Bohunice NPP V-1 units nuclear safety upgrading

    International Nuclear Information System (INIS)

    Mlcuch, M.

    2000-01-01

    Safety upgrading and operational reliability improvement was carried out by the Bohunice NPP V-1 staff continuously since the plant commissioning. By now, more than 1200 minor or major modifications have been implemented, either by the NPP maintenance staff or by the contractors. Based on findings of safety assessment missions invited by Bohunice NPP in 1990 - 1991, the Czecho-slovak Nuclear Regulatory Authority (CSKAE) issued the decision No. 5/91 of 81 safety upgrading measures to be taken in different areas. These improvements are referred to as the 'Small Reconstruction of the Bohunice V-1 NPP'. Realization of measures during Small reconstruction of the Bohunice NPP V-1 became a power plant, which further operation is acceptable from safety point of view, but it is also necessary further safety improvement. During the period of the Small Reconstruction the development of a Safety Report for the Gradual reconstruction has been completed. Based on this report the SR Nuclear Regulatory Authority issued the Decision No. 1/94, in which requires 59 upgrading measures in different areas to be addressed. The development of Basic Engineering of the Gradual Reconstruction has been contracted to the Siemens AG. Implementation of safety measures are provided through contract with the consortium REKON (which consists of Siemens AG company and Nuclear Power Plants Research Institute Trnava) and other Czech, Russian and Slovak companies. The Gradual Reconstruction of Bohunice NPP V-1 will be finished in 2000. By implementation of the measures carried out during Gradual Reconstruction achievement of an internationally acceptable nuclear safety level will be reached. (author)

  11. Design of fuel loading for Bohunice V-1 Unit 2 reaktor for fuel cycle No.19

    International Nuclear Information System (INIS)

    Majercik, J.

    1998-01-01

    The report contains description of the design of fuel loading for the fuel cycle No. 19 in the V-1 Bohunice Unit 2 reactor. Input data and computer codes used for the development of the design are shown. The fuel loading is characterized by the assortment of the fuel loaded and by the scheme of re shuffling of assemblies in the core. An evaluation of basic neutronic core parameters as relates to the compliance with safety criteria is a part of the report as well

  12. Bohunice V-1 and V-2 approach for achieving high availability, reliability and safety

    International Nuclear Information System (INIS)

    Lipar, M.; Kerak, J.; Rohar, S.

    1998-01-01

    Long term operating experience of Bohunice units maintenance activities are overviewed in the paper. Based on common experience of WWER NPP operators, separate maintenance department was established at Bohunice NPP in very early stage of plant operation. Maintenance management, maintenance planning, outage management, diagnostics and monitoring, inspection technologies and backfitting activities are described particularly to demonstrate the capability of Bohunice maintenance department for most complex repairs and maintenance works of nuclear power plant components and equipment, including reactor and turbine itself. (author)

  13. Commissioning tests at Bohunice NPP V1 unit 2 after reconstruction in 1998

    International Nuclear Information System (INIS)

    Pajtinka, A.; Tvaroska, V.; Wiening, K.-H.; Mueller, B.

    2000-01-01

    The last and the most extensive stage in the reconstruction project of the Bohunice NPP started in July 1998. The main activities performed during a 6-month scheduled unit 2 outage included: - Installation of a new emergency core cooling system with an increased capacity according to the defined broader break spectrum for LOCA; - Reconstruction of the existing confinement spray system and installation of a new confinement pressure suppression system; - Completion of upgrading measures to increase the reliability of emergency power supply systems (replacement of low voltage switchgear, installation of new cabling for all loads important to safety, installation of new motor-generators and rectifier sets); - Connection to the plant and commissioning of the new reactor protection system. Comprehensive tests and checks performed on completion of installation work on the modified mechanical, electrical and I and C systems were important reasons for the absence of major problems during restart of the unit after the several project implementation phases. Operating experience at unit 2 since its recommissioning in January 1999 has confirmed that the required safety standards have been met and that operational reliability has been substantially increased at the sometime. Periodic testing is being performed in accordance with the limits and conditions for safe operation of Bohunice NPP. To date all these tests were completed without significant problems. The functions implemented in the new technology met the test program criteria, which were approved with authority, in all essential areas. Through the close cooperation of the partners involved and through the combined efforts of the various engineering and operating disciplines, technical and scheduling problems could be immediately identified and quickly resolved. In general, these kinds of projects require optimum cooperation among the parties involved. Modernization of the NPP Bohunice V1 unit 2 has shown, that all

  14. Information about environmental effects of Bohunice NPPs V-1 and V-2 within February 2002

    International Nuclear Information System (INIS)

    2002-01-01

    In this leaflet the results of monitoring of chemical gaseous and liquid effluents into the rivers Vah and Dudvah as well as of radiation monitoring of Bohunice V-1 and V-2 NPPs are presented. The radioactive effluents within a February 2002 (for NPP V-1 and NPP V-2, respectively) were: 0.571 TBq and 0.664 TBq of rare gases, 0.711 MBq and 0.244 MBq of aero-soles, 2.121 MBq and 0.138 MBq of iodine, 2.022 MBq and 0.564 MBq of corrosive and fission products, and 1.420 TBq and 1.643 TBq of tritium. For the period January - February 2002 these radioactive effluents represent for rare gases 1.286 TBq for NPP V-1 and 1.475 TBq for NPP V-2 (2.761 TBq (0.069% of annually limit (AL) for the locality Bohunice), for aerosols 2.645 MBq for NPP V-1 and 0.542 MBq for NPP V-2 (3.187 MBq (0.002% of AL for the locality Bohunice), for corrosive and fission products 3.848 MBq for NPP V-1 and 1.510 MBq for NPP V-2 (5.358 MBq (0.01% of AL) for the locality Bohunice), and for iodine 2.616 MBq for NPP V-1 and 0.279 MBq (2.894 MBq (0.002% of AL) for the locality Bohunice), and for tritium it is 2.395 TBq for NPP V-1 and 3.532 TBq for NPP V-2 (5.358 TBq (13.56% of AL) for the locality Bohunice

  15. Main features of buildings and structures important to safety of units V1 and V2 of Bohunice NPP

    International Nuclear Information System (INIS)

    David, M.

    1993-01-01

    The program of seismic upgrading of Bohunice NPPs has been started in the year 1989 (after finishing of new seismic input). Since that time the seismic upgrading of Main building of NPP V1 has already been realized, structural as well as technological parts. Beside that the designs of seismic upgrading of other structures of NPP V1 and V2 have been completed. It has been proved that the seismic upgrading of NPPs with reactors WWER 440 is very complicated, but still possible, even in the case with high seismic intensity. It would be not possible to fulfill this complicated task without the help of IAEA Missions. The activities of IAEA experts in the program of Bohunice NPPs upgrading are appreciated very much

  16. Operation diagnostics of the reactor coolant pumps in the Jaslovske Bohunice nuclear power plant, CSSR

    International Nuclear Information System (INIS)

    Bahna, J.; Jaros, I.; Oksa, G.

    1990-01-01

    The state of the art of the materials basis, the diagnostics methods used, organization of data collection and processing, and some results of routine and specific investigations concerned with diagnosis of the reactor coolant pump in the Jaslovske Bohunice NPP V-1 are presented. Some information is given about the reactor coolant pump monitor developed in the VUJE. (author)

  17. Experience in modernization of safety I and C in VVER 440 nuclear power plants Bohunice V1 and Paks

    International Nuclear Information System (INIS)

    Martin, M.

    2000-01-01

    For nuclear power plants which have been in operation for more than 15 years, backfitting or even complete replacement of the instrumentation and control (I and C) equipment becomes an increasingly attractive option, motivated not only by the objective to reduce the cost of I and C system maintenance and repair but also to prolong or at least to safeguard the plant life-time: optimized spare-part management through use of standard equipment; reduction of number and variety of different items of equipment by implementing functions stepwise in application software; adding new functionality in the application software which was not possible in the old technology due to lack of space; safeguarding of long-term After-Sales-Service. Some years ago Bohunice V1 NPP, Slovak Republic and Paks NPP, Hungary intended to replace parts of their Safety I and C, mainly the Reactor Trip System, the Reactor Limitation System and the Neutron Flux Excore Instrumentation and Monitoring Systems. After a Basic Engineering Phase in Bohunice V1 and a Feasibility Study in Paks both plants decided to use the Siemens' Digital Safety I and C System TELEPERM XS to modernize their plants. Both Bohunice, Unit 2 and Paks, Unit 1 have been back on line for over six months with the new Digital Safety I and C. At the present time Bohunice, Unit 1 and within the next few months Paks, Unit 2 will be replaced. Trouble-free start-ups and no major problems under operation in the first two plants were based on: thorough understanding of the VVER 440 technology; comprehensive planning together with the plant operators and authorities; the possibility to adapt TELEPERM XS to every plant type; the execution of extensive pre-operational tests. Regarding these modernization measures Siemens, as well as the above Operators, have gained considerable experience in the field of I and C Modernization in VVER 440 NPPs. Important aspects of this experience are: how to transfer the VVER technology to TELEPERM XS; how to

  18. The preliminary results of the thermal annealing processes performed on the RPVs NPP V-1 in Jaslovske Bohunice

    Energy Technology Data Exchange (ETDEWEB)

    Kupca, L; Brezina, M; Beno, P [Vyskumny Ustav Jadrovych Elektrarni, Trnava (Slovakia)

    1994-12-31

    Samples of weld and base metal above and below the weld were taken from RPV material in the V-230 type NPP V-1 in Bohunice; hardness measurements were carried out across the weld on the external surface of the RPV under the thermal shielding, before and after annealing. Results are presented and the annealing procedure efficiency is discussed. (authors). 13 refs., 5 figs.

  19. Analysis of events significant with regard to safety of Bohunice V-1 nuclear power plant

    International Nuclear Information System (INIS)

    Suchomel, J.; Maron, V.; Kmosena, J.

    1986-01-01

    An analysis was made of operating safety of the V-1 nuclear power plant in Jaslovske Bohunice for the years 1980 - 1983. Of the total number of 676 reported failures only three were events with special safety significance, namely a complete loss of power supply for own consumption from the power grid, a failure of pins on the collectors of steam generators, and a failure of the heads of heat technology inspection channels. The failures were categorized according to the systems used in the USSR and in the USA and compared with data on failures in nuclear power plants in the two countries. The conclusions show that the operation of the V-1 nuclear power plant achieves results which are fully comparable with those recorded in 9 WWER-440 power plants operating in various countries. The average coefficient of availability is 0.72 and ranks the power plant in the fourth place among the said 9 plants. A comparison of the individual power plant units showed that of the total number of 22, the first unit of the V-1 plant ranks fifth with a coefficient of 0.78 and the second unit with a coefficient of 0.69 ranks 15th. (Z.M.)

  20. Evaluation of seismic resistance of low voltage switchgear, NPP V1 Jaslovske Bohunice, Slovakia

    International Nuclear Information System (INIS)

    Zeman, P.

    1999-01-01

    During this year, company Stevenson and Associates took part in the project of evaluation of seismic resistance of NPP V-1 Jaslovske Bohunice in Slovakia. It was responsible for a part of electrical equipment, mainly for the evaluation of low voltage switchgears. There were four steps of the evaluation: Detailed Walkdown; Application of GIP-WWER Methodology; Developing, of In Cabinet Response Spectra; and Evaluation of Acceptance of Formerly Performed Relay Tests According to the Russian Standard OEG l-330.00-3). Tests performed according to the Russian Standard OAG are acceptable only if the tested subject shows just one dominant natural frequency in the significant energy frequency range. If there is no knowledge of modal properties of the tested subject (that is a frequent situation because test reports usually contain only generalized Fourier loading spectrum) the enveloping of In Cabinet Response Spectra (ICRS) in all significant energy frequency ranges by Response Spectra (RS) of harmonic signal on one arbitrary frequency. This criteria is usually not satisfied because the shake tables used for the tests are not able to produce the sufficient level of excitation in the low frequency range. It may lead to the demand for test repeating

  1. Post-reconstruction full power and shut down level 2 PSA study for Unit 1 of Bohunice V1 NPP

    International Nuclear Information System (INIS)

    Kovacs, Z.

    2003-01-01

    The level 2 PSA model of the J. Bohunice V1 NPP was developed in the RISK SPECTRUM Professional code with the following objectives: to identify the ways in which radioactive releases from the plant can occur following the core damage; to calculate the magnitudes and frequency of the release; to provide insights into the plant behaviour during a severe accident; to provide a framework for understanding containment failure modes; the impact of the phenomena that could occur during and following core damage and have the potential to challenge the integrity of the confinement; to support the severe accident management and development of SAMGs. The magnitudes of release categories are calculated using: the MAAP4/VVER for reactor operation and shutdown mode with closed reactor vessel and the MELCOR code for shutdown mode with open reactor vessel. In this paper an overview of the Level 2 PSA methodology; description of the confinement; the interface between the level 1 and 2 PSA and accident progression analyses are presented. An evaluation of the confinement failure modes and construction of the confinement event trees as well as definition of release categories, source term analysis and sensitivity analyses are also discussed. The presented results indicate that: 1)for the full power operation - there is an 25% probability that the confinement will successfully maintain its integrity and prevent an uncontrolled fission product release; the most likely mode of release from the confinement is a confinement bypass after SGTM with conditional probability of 30%; the conditional probability for the confinement isolation failure probability without spray is 5%, for early confinement failure at the vessel failure is 4%, for other categories 1% or less; 2) for the shutdown operating modes - the shutdown risk is high for the open reactor vessel and open confinement; important severe accident sequences exists for release categories: RC5.1, RC5.2 and RC6.2

  2. Resin intrusion into the primary circuit of NPP Jaslovske Bohunice V-1

    International Nuclear Information System (INIS)

    Grezdo, O.; Mraz, V.

    2005-01-01

    During the refueling at the first unit of Bohunice NPP in 2005 a lot of sediment was found on the upper storage rack. This sediment was identification as a filter resin. Resin was found in most of the fuel assemblies, pipes and tanks of the primary circuit and his auxiliary systems. Resin producer and WANO network was contacted in order to get information about similar events. Management of Bohunice NPP made a decision that primary circuit, fuel assemblies and auxiliary systems have to be cleaned. Subsequent cleaning extended outage by 31 days. This paper summarizes causes, existing consequences and corrective actions. Accent was put on the hydraulic characteristics of the primary circuit measurement, power distribution core monitoring and the primary circuit water quality verification (Authors)

  3. Selective Leaching of aerosol particles collected by cascade impactor in the ventilation stack of NPP V1 in Jaslovske Bohunice

    Energy Technology Data Exchange (ETDEWEB)

    Rulik, P; Beckova, V; Bucina, I; Foltanova, S; Poliak, R [National Radiation Protection Institute, Prague (Czech Republic)

    1996-12-31

    The study was apart of investigation of the size distribution of aerosol in air effluents from NPP V1 Jaslovske Bohunice. The evaluation the possible relationship between aerodynamic diameter of aerosol particles and chemical forms of radionuclides attached to the discharged aerosol was tried. Selective leaching was used for speciation of radionuclides present in the aerosol particles and for the estimation of their behaviour in the environment and absorption in gastro-intestinal tract. Activity concentrations of the radionuclides in the air, collected on collection substrates taken from individual impact stages and on back-up filter, were determined by sensitive gamma-spectrometric analysis using high purity Ge detectors. For the individual groups seven leaching steps were used. Following 12 radionuclides: silver-110m, cobalt-58, cobalt-60, cesium-134, cesium-137, manganese-54, ruthenium-103, antimony-124, antimony-125, tin-113, zinc-65, zirconium-95. Result shows that the leached fraction of the of the activity concentration does not depend on the size of the aerosol particles. (J.K.) 3 tabs., 3 figs.

  4. Complex nuclear safety evaluation of the Bohunice V-1 nuclear power plant

    International Nuclear Information System (INIS)

    Kriz, Z.

    1991-01-01

    The safety concept of V-230 type reactor units dates back to the late 1960s. The units fail to be sufficiently dimensioned for emergency cooling of the reactor core and are fitted with no containment. So far, operating experience is good. The availability factor is 71.5% for unit 1 and 77.8% for unit 2. There occur 1 to 3 unscheduled shutdowns annually. The quality of steam generator tubes is very good. A complex safety assessment of the plant was accomplished in 1990. It concerned the concept and criteria of safety assessment, the earthquake situation, the condition of the primary coolant circuit equipment, the control system, the effect of the human factor, and preparedness of emergency plans. OSART and ASSET missions were accomplished at the plant. Based on the results of the missions as well as of inspections by the State Surveillance over Nuclear Safety, the decision has been adopted to operate the plant not longer than till 1995; the further fate of the plant will be decided on according to a future technical and economic analysis. (M.D.)

  5. Analytical and experimental verification of confinement upgrading for Bohunice NPP V1

    International Nuclear Information System (INIS)

    Tkac, A.

    2000-01-01

    The scope of this paper is to provide a brief description of confinement improvement for NPP V-1 and supporting thermal-hydraulic analyses and experimental results. Series of analyses are performed in the process of the designing of an improved confinement system. Based on the analytical results obtained in the PHARE Project NS01/91 'Confinement and Improved ECCS Evaluation' as well as on additional activities performed after its finishing, additional modifications have been proposed during the designing. It is required to minimize the construction works EWST ceiling, while final solution shall fulfil acceptance criteria set forth in Decision 1/94 of Slovak Regulatory Authority (UJD). The technical requirement of the UJD is related to confinement. IAEA recommendations are taken into account. Due to new definitions of DBA and BDBA first considerations were connected and oriented on possible value of pressure peak increasing. As a result of the structural analysis limiting values for hermetic zone are determined. Some design modifications of the hermetic zone are proposed

  6. Bituminization plant Jaslovske Bohunice

    International Nuclear Information System (INIS)

    1999-01-01

    In this leaflet the principle of the bituminization plant for radioactive concentrate (the intermediate liquid radioactive waste generated during the NPP A1, V-1, V-2 operations) solidification used in the Bohunice Radwaste Treatment Centre (BSC RAO) is presented

  7. Nuclear power plant V-1

    International Nuclear Information System (INIS)

    1998-01-01

    The nuclear power plant Bohunice V -1 is briefly described. This NPP consists from two reactor units. Their main time characteristics are (Reactor Unit 1, Reactor Unit 2): beginning of construction - 24 April 1972; first controlled reactor power - 27 November 1978, 15 March 1980; connection to the grid - 17 December 1978, 26 March 1980; commercial operation - 1 April 1980, 7 January 1981. This leaflet contains: NPP V-1 construction; Major technological equipment (Primary circuit: Nuclear reactor [WWER 440 V230 type reactor];Steam generator; Reactor Coolant Pumps; Primary Circuit Auxiliary Systems. Secondary circuit: Turbine generators, Nuclear power plant electrical equipment; power plant control) and technical data

  8. Thirtieth anniversary of reactor accident in A-1 Nuclear Power Plant Jaslovske Bohunice

    International Nuclear Information System (INIS)

    Kuruc, J.; Matel, L.

    2007-01-01

    The facts about reactor accidents in A-1 Nuclear Power Plant Jaslovske Bohunice, Slovakia are presented. There was the reactor KS150 (HWGCR) cooled with carbon dioxide and moderated with heavy water. A-1 NPP was commissioned on December 25, 1972. The first reactor accident happened on January 5, 1976 during fuel loading. This accident has not been evaluated according to the INES scale up to the present time. The second serious accident in A-1 NPP occurred on February 22, 1977 also during fuel loading. This INES level 4 of reactor accident resulted in damaged fuel integrity with extensive corrosion damage of fuel cladding and release of radioactivity into the plant area. The A-1 NPP was consecutively shut down and is being decommissioned in the present time. Both reactor accidents are described briefly. Some radioecological and radiobiological consequences of accidents and contamination of area of A-1 NPP as well as of Manivier Canal and Dudvah River as result of flooding during the decommissioning are presented (authors)

  9. Nuclear power plant V-1

    International Nuclear Information System (INIS)

    1999-01-01

    In this leaflet the short history of commissioning of Bohunice V-1 NPP is reviewed (beginning of construction 24 April 1972; First controlled reactor power, Reactor Unit 1 (RU1): 27 November 1978, Reactor Unit 2 (RU2): 15 March 1980; Connection to the grid: RU1 17 December 1978, RU2 26 March 1980; Commercial operation: RU1 1 April 1980, RU2 7 January 1981. The scheme of the nuclear reactor WWER 440/V230 is depicted. The major technological equipment (primary circuit, nuclear reactor, steam generators, reactor coolant pumps, primary circuit auxiliary systems, secondary circuit, turbine generators, NPP electrical equipment, and power plant control) are described. Technical data of the Bohunice V-1 NPP are presented

  10. The LBB methodology application results performed on the safety related piping of NPP V-1 in Jaslovske Bohunice

    Energy Technology Data Exchange (ETDEWEB)

    Kupca, L.; Beno, P. [Nuclear Power Plants Research Institute, Trnava (Slovakia)

    1997-04-01

    A broad overview of the leak before break (LBB) application to the Slovakian V-1 nuclear power plant is presented in the paper. LBB was applied to the primary cooling circuit and surge lines of both WWER 440 type units, and also used to assess the integrity of safety related piping in the feed water and main steam systems. Experiments and calculations performed included analyses of stresses, material mechanical properties, corrosion, fatigue damage, stability of heavy component supports, water hammer, and leak rates. A list of analysis results and recommendations are included in the paper.

  11. Bohunice Nuclear Power Plant Safety Upgrading Program

    International Nuclear Information System (INIS)

    Toth, A.; Fagula, L.

    1996-01-01

    Bohunice nuclear Power Plant generation represents almost 50% of the Slovak republic electric power production. Due to such high level of commitment to nuclear power in the power generation system, a special attention is given to safe and reliable operation of NPPs. Safety upgrading and operational reliability improvement of Bohunice V-1 NPP was carried out by the Bohunice staff continuously since the plant commissioning. In the 1990 - 1993 period extensive projects were realised. As a result of 'Small Reconstruction of the Bohunice V-1 NPP', the standards of both the nuclear safety and operational reliability have been significantly improved. The implementation of another modifications that will take place gradually during extended refuelling outages and overhauls in the course of 1996 through 1999, is referred to as the Gradual Reconstruction of the Bohunice V-1 Plant. The general goal of the V-1 NPP safety upgrading is the achievement of internationally acceptable level of nuclear safety. Extensive and financially demanding modification process of Bohunice V-2 NPP is likely to be implemented after a completion of the Gradual Reconstruction of the Bohunice V-1 NPP, since the year 1999. With this in mind, a first draft of the strategy of the Bohunice V-2 NPP upgrading program based on Probabilistic Safety assessment consideration was developed. A number of actions with a general effect on Bohunice site safety is evident. All these activities are aimed at reaching the essential objective of Bohunice NPP Management - to ensure a safe, reliable and effective electric energy and heat generation at the Bohunice site. (author)

  12. Safety enhancement in NPP Bohunice

    International Nuclear Information System (INIS)

    Lipar, M.; Mihalik, M.

    1997-01-01

    The upgrading and safety enhancement of both the Bohunice V-1 and V-2 reactors is described in detail. The total estimated cost of the gradual reconstruction of these two units during 1996 to 1999 is 180 mil. US dollars. For the 1995 to 1997 period, the actions common for both units include a quality assurance programme, a personnel training programme, installation of a multifunction simulator, implementation of symptom-oriented operation procedures, installation of diagnostic systems, of a site security system, and of a teledosimetric system. At present, the main maintenance tasks are: to carry out major repair of units, to remedy service interruptions, to enhance equipment service availability, to enhance the technical level of corrective actions at equipment. Investment into maintenance level upgrade has grown from 7.5 mil. Slovak crowns in 1994 to estimated 32 mil. in 2000. The partners of international cooperation are mentioned. (M.D.)

  13. The primary circuit materials properties results analysis performed on archive material used in NPP V-1 and Kola NPP Units 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    Kupca, L.; Beno, P. [Nuclear Power Plants Research Institute Inc., Trnava (Slovakia)

    1997-04-01

    A very brief summary is provided of a primary circuit piping material properties analysis. The analysis was performed for the Bohunice V-1 reactor and the Kola-1 and -2 reactors. Assessment was performed on Bohunice V-1 archive materials and primary piping material cut from the Kola units after 100,000 hours of operation. Main research program tasks included analysis of mechanical properties, corrosion stability, and microstructural properties. Analysis results are not provided.

  14. Optimization of radiation protection at Bohunice NPP

    International Nuclear Information System (INIS)

    Dobis, L.; Svitek, J.

    2003-01-01

    Bohunice Nuclear Power Plant is situated in south - western part of Slovakia about 50 km away from Bratislava. There are four PWR reactors 440 MW e each - two units with reactors WWER - 230 (V1 NPP) and two units with WWER - 213 (V2 NPP). requirements for the optimization process are given in the mentioned Code No.12 of Ministry of Health. Code 12 stipulates the technical and organizational requirements for proving the Rational Achievable Level (RAL) of radiation protection. This level can be proved by means of the comparison of the dose distribution to the costs of protection. An example of two figures of dose constraints is: collective dose 20 man mSv for the specific task; individual exposure 1 mSv per day. The values of the financial equivalents of personal exposure - so called the alpha coefficients - are used for the calculation of the benefit of proposed measures. Impact of legislative changes into Bohunice NPP and optimization process are presented. Apparently the new law and the associate code created a base of transparent and understandable policy of radiation protection and optimization in Slovak Republic. The radiation protection legislative was implemented into the praxis and persons became familiar with it. Defining clear and unambiguous terms facilitated the communication between users and the regulatory body - State Health Institute. Optimization was generally accepted by the workers and managers and began to be a part of safety culture of operation at nuclear power plants. (authors)

  15. Lifetime evaluation of Bohunice NPP components

    International Nuclear Information System (INIS)

    Kupca, L.

    2001-01-01

    The paper discuss some aspects of the main primary components lifetime evaluation program in Bohunice NPP which is performed by Nuclear Power Plant Research Institute (NPPRI) Trnava in cooperation with Bohunice and other organizations involved. Facts presented here are based on the NPPRI research report which is regularly issued after each reactor fuel campaign under conditions of project resulted from the contract between NPPRI and Bohunice NPP. For the calculations, there has been used some computer codes adapted (or made) by NPPRI and the results are just the conclusive and very brief, presented here in Tables (Figures). (authors)

  16. Modernization and safety improvement project of the NPP V-2 Jaslovske Bohunice

    International Nuclear Information System (INIS)

    Michal, V.; Losonsky, B.; Magdolen, J.

    2000-01-01

    This contribution deals with the form, present state, and results of the Nuclear Power Plants Research Institute (the Slovak acronym is VUJE - Vyskumny Ustav Jadrovych Elektrarni) participation in the NPP V-2 Jaslovske Bohunice Modernization and Safety Improvement Project. A short description of VUJE history, activity, and results is also presented as well as NPPs Jaslovske Bohunice characterization. VUJE was established in 1977 and deals with scientific and research needs of nuclear power plants, such as design, construction, commissioning and operation. The next fields of VUJE activity are, NPP reconstruction, NPP personnel training, radioactive waste management technology, and NPP decommissioning. The nuclear power plant, Jaslovske Bohunice, is situated approximately 15 km from the district town of Trnava in the southwestern region of the Slovak Republic. The construction of the first Czechoslovak NPP A-1 began on this site in 1957 .The construction of the double-unit NPP V-1 with WWER-440 (type V-230) reactor began in 1972. The first unit of NPP V-1 began operation in 1978 and the second in 1980. NPPs construction on the Bohunice site continued with NPP V-2, which has two units with WWER-440 (type V-213) reactors. Unit 1 and Unit 2 of NPP V-2 were commissioned in 1984 and 1985, respectively. Slovak electric utility Slovenske elektrarne (SE) is the owner/commissioner of NPP V-2. This NPP is responsible for more than 20% of the total electrical energy production of SE, making it an essential supporter of the Slovak economy. (authors)

  17. Radwaste Treatment Centre Jaslovske Bohunice

    International Nuclear Information System (INIS)

    2000-01-01

    In this leaflet the Bohunice Radwaste Treatment Centre (BSC RAO) is presented. BSC RAO is designed to process and treat liquid and solid radwaste, arising from the NPP A-1 decommissioning, from NPPs V-1, V-2, and Mochovce operations, as well as institutional radwaste of diverse institutional (hospitals, research institutes) in the Slovak Republic. Transport, sorting, incineration, compacting, concentration and cementation of radwaste as well as monitoring of emission are described

  18. Research reactor core conversion guidebook. V.1: Summary

    International Nuclear Information System (INIS)

    1992-04-01

    In view of the proliferation concerns caused by the use of highly enriched uranium (HEU) and in anticipation that the supply of HEU to research and test reactors will be more restricted in the future, this guidebook has been prepared to assist research reactor operators in addressing the safety and licensing issues for conversion of their reactor cores from the use of HEU fuel to the use of low enriched uranium fuel. This Guidebook, in five volumes, addresses the effects of changes in the safety-related parameters of mixed cores and the converted core. It provides an information base which should enable the appropriate approvals processes for implementation of a specific conversion proposal, whether for a light or for a heavy water moderated research reactor. Refs, figs, bibliographies and tabs

  19. Fusion reactor design and technology 1986. V. 1

    International Nuclear Information System (INIS)

    1987-01-01

    The first volume of the Proceedings of the Fourth Technical Committee Meeting and Workshop on Fusion Reactor Design and Technology organized by the IAEA (Yalta, 26 May - 6 June 1986) includes 36 papers devoted to the following topics: fusion programmes (3 papers), tokamaks (15 papers), non-tokamak reactors and open systems (9 papers), inertial confinement concepts (5 papers), fission-fusion hybrids (4 papers). Each of these papers has a separate abstract. Refs, figs and tabs

  20. Material properties of Bohunice 1 and 2 reactor pressure vessel materials before and after annealing

    International Nuclear Information System (INIS)

    Brumovsky, M.; Novosad, P.; Vacek, M.

    1994-01-01

    Six types of experimental RPV materials were studied before and after irradiation in host nuclear power and research reactors. Recovery of RPV materials from radiation hardening and embrittlement after annealing was evaluated including a rate of radiation damage after reirradiation used. (author). 3 refs, 4 figs, 2 tabs

  1. Bohunice Simulator Data Collection Project

    International Nuclear Information System (INIS)

    Cillik, Ivan; Prochaska, Jan

    2002-01-01

    The paper describes the way and results of human reliability data analysis collected as a part of the Bohunice Simulator Data Collection Project (BSDCP), which was performed by VUJE Trnava, Inc. with funding support from the U.S. DOE, National Nuclear Security Administration. The goal of the project was to create a methodology for simulator data collection and analysis to support activities in probabilistic safety assessment (PSA) and human reliability assessment for Jaslovske Bohunice nuclear power plant consisting of two sets of twin units: two VVER 440/V-230 (V1) and two VVER 440/V-213 (V2) reactors. During the project training of V-2 control room crews was performed at VUJE-Trnava simulator. The simulator training and the data collection were done in parallel. The main goal of BSDCP was to collect suitable data of human errors under simulated conditions requiring the use of symptom-based emergency operating procedures (SBEOPs). The subjects of the data collection were scenario progress time data, operator errors, and real-time technological parameters. The paper contains three main parts. The first part presents preparatory work and semi-automatic computer-based methods used to collect data and to check technological parameters in order to find hidden errors of operators, to be able to retrace the course of each scenario for purposes of further analysis, and to document the whole training process. The first part gives also an overview of collected data scope, human error taxonomy, and state classifications for SBEOP instructions coding. The second part describes analytical work undertaken to describe time distribution necessary for execution of various kinds of instructions performed by operators according to the classification for coding of SBEOP instructions. It also presents the methods used for determination of probability distribution for different operator errors. Results from the data evaluation are presented in the last part of the paper. An overview of

  2. Bohunice Simulator Data Collection Project

    International Nuclear Information System (INIS)

    Cillik, I.; Prochaska, J.

    2002-01-01

    The paper describes the way and results of human reliability data analysis collected as a part of the Bohunice Simulator Data Collection Project (BSDCP), which was performed by VUJE Trnava, Inc. with funding support from the U.S. DOE, National Nuclear Security Administration. The goal of the project was to create a methodology for simulator data collection and analysis to support activities in probabilistic safety assessment (PSA) and human reliability assessment for Jaslovske Bohunice nuclear power plant consisting of two sets of twin units: two VVER 440/V-230 (V1) and two VVER 440/V-213 (V2) reactors. During the project, training of V-2 control room crews was performed at VUJE Trnava simulator. The simulator training and the data collection were done in parallel. The main goal of BSDCP was to collect suitable data of human errors under simulated conditions requiring the use of symptom-based emergency operating procedures (SBEOPs). The subjects of the data collection were scenario progress time data, operator errors, and real-time technological parameters. The paper contains three main parts. The first part presents preparatory work and semi-automatic computer-based methods used to collect data and to check technological parameters in order to find hidden errors of operators, to be able to retrace the course of each scenario for purposes of further analysis, and to document the whole training process. The first part gives also an overview of collected data scope, human error taxonomy, and state classifications for SBEOP instructions coding. The second part describes analytical work undertaken to describe time distribution necessary for execution of various kinds of instructions performed by operators according to the classification for coding of SBEOP instructions. It also presents the methods used for determination of probability distribution for various operator errors. Results from the data evaluation are presented in the last part of the paper. An overview of

  3. Radiation protection in Bohunice NPP. Description of present status

    International Nuclear Information System (INIS)

    Dobis, L.

    2001-01-01

    Radiation protection (RP) at Bohunice NPP has reached the high international standard. The fact was approved by several independent international missions (OSART , WANO, WENRA, ...). A lot of modifications have been done in order to improve the standard of radiation protection. All the BSS requirements have been implemented into the plant regulations before the State Law No 290/1996 and 470/2000 came into the force. Internal audits are regularly performed at NPP in order to reveal potential deficiencies. In 2001 there were 4 such audits focused on quality assurance, software operation, LBB concept and limits and condition of safe operation. State Health Institute, the regulatory body in the radiation protection, performs the inspection at least ones a month. Good relationship with the inspectors of State Health Institute also contributes to the safe operation of the NPP. There were not any radiation accident. All anomalies or radiation events are investigated at a plant level. The results of root cause analysis and proposal of corrective actions are provided to IAEA and WANO databases for the distribution. The Radiation protection department of Bohunice NPP cooperates with the other Czech and Slovak NPPs. Regular meetings on radiation protection and lately also on emergency preparedness are organized. The cooperation is excellent. Occupational exposure is reviewed also with respect of ISOE data. Bohunice NPP (even with high dose burden caused by reconstruction of V1 NPP) can be found in the first half of world PWR speaking about the collective exposure per reactor. V2 NPP itself reaches the lowest collective exposure in the world. All doses are below the limits and kept ALARA. ALARA system has been established already in 1997 at Bohunice NPP and its results are obvious for example looking at dose results during the reconstruction works at V1 NPP. The operation of Bohunice NPP has negligible influence to its surroundings. The values of gas and liquid effluents move

  4. Foreword by the director of Bohunice NPPs

    International Nuclear Information System (INIS)

    1998-01-01

    In this foreword the director briefly describes activities of the NPP Bohunice in 1997. Main activities were: electric and heat production , the V-1 NPP Gradual Reconstruction Programme, nuclear safety programmes, environment protection, international co-operation as well as national and international public information

  5. Primary system hydraulic characteristics after modification of reactor coolant pumps' impeller wheels at Bohunice NPP executed in 2012 and 2013

    International Nuclear Information System (INIS)

    Hermansky, Jozef; Zavodsky, Martin

    2014-01-01

    A coolant flow through the reactor is usually determined after annual outages at Slovak NPP (VVER 440) in two distinct ways. First method is determination on the basis of the secondary system parameters - measurement of thermal balances. The value achieved by this method is used as the input parameter in the Table of allowed reactor operation modes. The second method draws from the primary system parameters - measurement of primary system hydraulic characteristics. Flow nozzles used for the measurement of feed water flow behind high pressure heaters were replaced at both Bohunice Units during outages in 2008. The feed water flow behind high pressure heaters is one of the main parameters used for the determination of coolant flow through the reactor by the first method. Compared to the measurement executed during previous fuel cycles, the calculated coolant flow through the reactor decreased considerably after the change of flow nozzles. The imaginary change of coolant flow through the reactor at Unit 3 was -1,6 %; and at Unit 4 -2,6 %. This change was not proved by the parallel measurement of primary system hydraulic characteristics. Later it was found out that the original flow nozzles used for 25 years were substantially deposited (original inner diameter of the nozzles was reduced by about 0,6-0,9 mm). Therefore feed water flow measurement was untrustworthy within the recent years. On the findings stated above, Bohunice NPP has decided to increase coolant flow through the reactor by changing the reactor coolant pumps impeller wheels. The modification of impellers wheels is planned within years 2012 to 2014. During the outages in 2013 two impeller wheels were replaced at both units. Nowadays Unit 4 is operated with all 6 new impeller wheels and Unit 3 with four new impeller wheels. Modification of last two impeller wheels at Unit 3 will be performed during the outage in 2014. On account of impeller wheels modification, non-standard measurement of PS hydraulic

  6. Slovak power stations, Nuclear power plants Jaslovske Bohunice. (Annual report 1997)

    International Nuclear Information System (INIS)

    1998-01-01

    A brief account of activities carried out by the Nuclear power plants Jaslovske Bohunice in 1997 is presented. These activities are reported under the headings: (1) Foreword by the director of Bohunice NPPs; (2) Management of Bohunice NPPs Subsidiary Plant; (3) The most significant events of the year 1997; (4) Electricity and heat production; (5) Safety; (6) Bohunice NPPs operation impact on environment; (7) The V-1 NPP and V-2 NPP upgrading; (8) Maintenance; (9) Capital construction; (10) Economic balance; (11) International co-operation; (12) Human sources; (12) Public relations

  7. Seismic evaluation and strengthening of Bohunice nuclear power plant structures

    International Nuclear Information System (INIS)

    Shipp, J.G.; Short, S.A.; Grief, T.; Borov, V.; Kuzma, J.

    2001-01-01

    A seismic assessment and strengthening investigation is being performed for selected structures at the Bohunice V1 Nuclear Power Plant in Slovakia. Structures covered in this paper include the reactor building complex and the emergency generator station. The emergency generator station is emphasized in the paper as work is nearly complete while work on the reactor building complex is ongoing at this time. Seismic evaluation and strengthening work is being performed by a cooperative effort of Siemens and EQE along with local contractors. Seismic input is the interim Review Level Earthquake (horizontal peak ground acceleration of 0.3 g). The Bohunice V1 reactor building complex is a WWER 4401230 nuclear power plant that was originally built in the mid-1970s but had extensive seismic upgrades in 1991. Siemens has performed three dimensional dynamic analyses of the reactor building complex to develop seismic demand in structural elements. EQE is assessing seismic capacities of structural elements and developing strengthening schemes, where needed. Based on recent seismic response analyses for the interim Review Level Earthquake which account for soil-structure interaction in a rigorous manner, the 1991 seismic upgrade has been found to be inadequate in both member/connection strength and in providing complete load paths to the foundation. Additional strengthening is being developed. The emergency generator station was built in the 1970s and is a two-story unreinforced brick masonry (URM) shear wall building above grade with a one story reinforced concrete shear wall basement below grade. Seismic analyses and testing of the URM walls has been performed to assess the need for building strengthening. Required structural strengthening for in-plane forces consists of revised and additional vertical steel framing and connections, stiffening of horizontal roof bracing, and steel connections between the roof and supporting walls and pointing of two interior transverse URM

  8. Metamorphosis of NPP A1, V1, V2

    International Nuclear Information System (INIS)

    Dobak, D.; Moncekova, M.

    2005-01-01

    In this book the history of construction, commissioning and exploitation of NPP A1, NPP V1 and NPP V2 in Jaslovske Bohunice is presented on documentary photos. Vicinity around of these NPPs is presented, too

  9. Experience with construction and assembly of V-1 nuclear power plant

    International Nuclear Information System (INIS)

    Prochazka, J.; Stepanek, S.; Drahy, J.

    1981-01-01

    The model is discussed of the constructions of the V-1 nuclear power plant at Jaslovske Bohunice with SKODA Trust fulfilling the role of the general supplier of the secondary part technology and the chief and special assembly contractor. The SKODA Trust mediated the Soviet supplies of technology, Soviet assembly and special assembly, and the mounting of the primary part according to Soviet projects. Plant start-up was safeguarded by the investor through Bohunice power plant staff and Soviet experts. The assembly of the primary circuit and the test assembly of reactor parts are described and the experience gained is discussed. The technological requirements are illustrated by the most important characteristics of the individual parts of the primary circuit. Also described are the design specifications of the 220 MW saturated steam turbine and the experience with its assembly and start-up. (B.S.)

  10. Final results of the gradual reconstruction of Bohunice VI in Slovakia and evaluation of the reconstruction by international missions

    International Nuclear Information System (INIS)

    Ferenc, M.

    2001-01-01

    The gradual reconstruction of the Bohunice V1 nuclear power plant (Slovakia) represents the most extensive reconstruction of a nuclear power plant in operation as implemented worldwide up to now. Extensive reconstruction works in both civil construction and process parts, in instrumentation and control part, and in electric part enhanced both nuclear safety and operational reliability of Bohunice V1 in a significant way.(author)

  11. Safety improvement programme of WWER 440/230 units in Jaslovske Bohunice

    International Nuclear Information System (INIS)

    Tomek, J.

    2000-01-01

    A brief overview is given of the power sources in Slovakia which include 6 operational reactor units (4 at Jaslovske Bohunice and 2 at Mochovce) and 2 units under construction (at Mochovce). The efforts undertaken in the past 10 years and aimed at upgrading the nuclear safety of the two older (V-230 Soviet type) units at Bohunice are highlighted. The relevant regulatory decisions are dealt with and the measures already carried out are listed. Also characterized are several IAEA international safety assessment missions and safety-aimed meetings which took place in 1998 and 1999 and are of concern to the older Bohunice units. (A.K.)

  12. Internal communication at Bohunice NPPs

    International Nuclear Information System (INIS)

    Dobdk, Dobroslav

    1999-01-01

    Communication is the base of everyday existence of a modern person and every company. It is not easy to work in this area in a changing 'eastern' country. Many tools, which are used are in the mind of people connected with 'propaganda'. I would like to share our experience with you. The goal of an internal communication is to spread and provide continuous current of objective information between the management of Bohunice NPPs and its personnel and between the personnel itself. Communication with the Bohunice NPPs employees helps to get acquainted with their opinions and ideas concerning the subsidiary and nuclear power industry

  13. Chemical composition determination of Bohunice 1 and 2 RPVs and hardness measurements of RPVs material

    International Nuclear Information System (INIS)

    Kupca, L.; Brezina, M.; Beno, P.; Kniz, I.

    1994-01-01

    The base informations of all activities concerning the material properties recovery performed before and after annealing procedure on the first two units V-230 type in NPP V-1, are the topic of this paper. The samples of weld and base metal from both RPVs NPP V-1 were prepared by special apparatus in the very narrow gap between the outside surface of the RPV and the reactor thermal shielding in the reactor cavity, from the critical circumferential weld joint no.4. The chemical composition of the samples was analyzed in Nuclear Power Plants Research Institute (VUJE) laboratories. Except these results achieved from the analysis of the irradiated samples are presented the evaluation results of the chemical composition influence on the RPVs materials brittle fracture temperatures. All these results which served as input data for the irradiation embrittlement recovery evaluation of the both RPV NPP V-1 in Jaslovske Bohunice, are presented in the form of the trend curves for both RPVs. (author). 10 refs, 7 figs, 1 tab

  14. Verification of RBMK-1500 reactor main circulation circuit model with Cathare V1.3L

    International Nuclear Information System (INIS)

    Jasiulevicius, A.

    2001-01-01

    Among other computer codes, French code CATHARE is also applied for RBMK reactor calculations. In this paper results of such application for Ignalina NPP reactor (RBMK-1500 type) main circulation circuit are presented. Three transients calculations were performed: all main circulation pumps (MCP) trip, trip of one main circulation pump and trip of one main circulation pump without a closure of check valve on the pump line. Calculation results were compared to data from the Ignalina NPP, where all these transients were recorded in the years 1986, 1996 and 1998. The presented studies prove the capability of the CATHARE code to treat thermal-hydraulic transients with a reactor scram in the RBMK, in case of single or multiple pump trips. However, the presented model needs further improvements in order to simulate loss of coolant accidents. For this reason, emergency core cooling system should be included in the model. Additional model improvement is also needed in order to gain more independent pressure behavior in both loops. Also, flow rates through the reactor channels should be modeled by dividing channels into several groups, referring to channel power (in RBMK power produced in a channel, located in different parts of the core is not the same). The point-neutron kinetic model of the CATHARE code is not suitable to predict transients when the reactor is operating at a nominal power level. Such transients would require the use of 3D-neutron kinetics model to describe properly the strong space-time effect on the power distribution in the reactor core

  15. The EUCLID/V1 Integrated Code for Safety Assessment of Liquid Metal Cooled Fast Reactors. Part 1: Basic Models

    Science.gov (United States)

    Mosunova, N. A.

    2018-05-01

    The article describes the basic models included in the EUCLID/V1 integrated code intended for safety analysis of liquid metal (sodium, lead, and lead-bismuth) cooled fast reactors using fuel rods with a gas gap and pellet dioxide, mixed oxide or nitride uranium-plutonium fuel under normal operation, under anticipated operational occurrences and accident conditions by carrying out interconnected thermal-hydraulic, neutronics, and thermal-mechanical calculations. Information about the Russian and foreign analogs of the EUCLID/V1 integrated code is given. Modeled objects, equation systems in differential form solved in each module of the EUCLID/V1 integrated code (the thermal-hydraulic, neutronics, fuel rod analysis module, and the burnup and decay heat calculation modules), the main calculated quantities, and also the limitations on application of the code are presented. The article also gives data on the scope of functions performed by the integrated code's thermal-hydraulic module, using which it is possible to describe both one- and twophase processes occurring in the coolant. It is shown that, owing to the availability of the fuel rod analysis module in the integrated code, it becomes possible to estimate the performance of fuel rods in different regimes of the reactor operation. It is also shown that the models implemented in the code for calculating neutron-physical processes make it possible to take into account the neutron field distribution over the fuel assembly cross section as well as other features important for the safety assessment of fast reactors.

  16. Fire fighting precautions at Bohunice Atomic Power Plants

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    Some shortcomings are discussed of the project design of fire protection at the V-1 and V-2 nuclear power plants. The basic shortcoming of the system is insufficient division of the units for fire protection. Fire fighting measures are described for cable areas, switch houses and outside transformers, primary and secondary circuits and auxiliary units. Measures are presented for increasing fire safety in Jaslovske Bohunice proceedi.ng from experience gained with a fire which had occurred at a nuclear power plant in Armenia. (E.S.)

  17. New Emergency control center of Slovenske Elektrarne Bohunice NPP

    International Nuclear Information System (INIS)

    Pecko, E.

    2012-01-01

    Emergency preparedness of nuclear power plant and operation assurance in case of a possible emergency calls to have devices for emergency response with equipment for rapid detection and continuous evaluation of anticipated events. Chief executive body designated to manage a nuclear power plant during major events is the emergency committee (EC). Emergency Committee is a part of the Emergency Response Organization (ERO). The following centers are on alert to ensure the activities of the ERO - Emergency Response office: - control room (CR) and emergency control room (ECR); - emergency management center (EMC); - Monitoring Centre (MC); - emergency backup control center (EBCC); - congregations of civil protection (CP) and CP shelters; - communications with warning and notification system (VARVYR). From a historical and practical point of view in the vicinity of Jaslovske Bohunice has been set up a joint emergency control center. The center was located on the territory of the former already inoperative V1 NPP. V1 NPP is currently integrated into the organizational structure of JAVYS. Operating Bohunice V2 NPP plant is a designated part of the Slovenske Elektrarne, a. s., whose majority owner is an Italian operator ENEL. In terms of various relevant factors, it was decided to build a new emergency management center on the territory of operating V2 NPP, meet the current standards.

  18. Heat delivery from Bohunice NPP, Slovakia

    International Nuclear Information System (INIS)

    Paley, I.

    1998-01-01

    Experience with nuclear district heating in the Slovak Republic is reported. The heating system of the town of Trnava is supplied by the Bohunice NPP and conventional sources. Construction of the hot water heating system from the Bohunice NPP began in 1983. Commercial operation began on 10 December 1987. Heat delivery has gradually increased from 478 TJ in 1988, to 1,104 TJ in 1995. The heat cost is low, resulting in an increasing number of consumers. (author)

  19. Reuse of discharged fuel in Bohunice-1,2 units

    International Nuclear Information System (INIS)

    Chrapciak, V.; Majercik, J.; Kacmar, M.

    2003-01-01

    During the reconstruction of Bohunice-1,2 units (1997 - 2001), their cycle lengths dropped to very short values. Because of 4-year limit to fuel residence time, refuelling with fresh 2.4 % enriched assemblies seemed to be a solution of the problem. The paper describes the implementation of a final decision to reuse 3.6 % enriched fuel discharged after 3-year irradiation in previous cycles. This decision led to a large-scale moving of discharged assemblies from spent fuel pools back to reactors (Authors)

  20. Seismic strengthening of nuclear power plants V1-V2 structures in Slovak Republic

    International Nuclear Information System (INIS)

    David, M.

    1993-01-01

    The structural upgrading of main buildings of Bohunice NPP units V1 and V2 is described in this presentation. Design criteria for structural upgrading are included. Since the seismic upgrading of the existing NPP is usually very complicated and expensive task, designer is obliged to find the optimal solution between the economics and reliability of the upgrading. The assistance of IAEA missions during the process of Bohunice seismic upgrading is considered very fruitful

  1. District heating by the Bohunice nuclear power plant

    International Nuclear Information System (INIS)

    Metke, E.; Skvarka, P.

    1984-01-01

    Technical and economical aspects of district heating by the electricity generating nuclear plants in Czechoslovakia are discussed. As a first stage of the project, 240 MW thermal power will be supplied using bleeding lines steam from the B-2 nuclear power plant at Jaslovske Bohunice to heat up water at a central station to 130 grad C. The maximal thermal power that can be produced for district heating by WWER type reactors with regular condensation turbines is estimated to be: 465 MW for a WWER-440 reactor with two 220 MWe turbines and 950 MW for a WWER-1000 reactor with a Skoda made 1000 MWe turbine using a three-stage scheme to heat up water from 60 grad C to 150 grad C. The use of satelite heating turbines connected to the steam collector is expected to improve the efficiency. District heating needs will de taken into account for siting of the new power plants

  2. Bohunice NPPs - Part of the Slovak's economy (sustainable) development

    International Nuclear Information System (INIS)

    Dobak, Dobroslav

    2001-01-01

    Of the total consumption of electricity in Slovakia, 42% was generated in nuclear power plant units in 1999. Slovakia operates 6 units with a WWER 440 nuclear reactors, 4 of them are at Bohunice site and 2 at Mochovce. The Nuclear Regulatory Authority of SR is not the only regulatory body controlling nuclear activity. Both - the system of nuclear activities regulation in Slovakia as well as the approach to Nuclear Safety enhancement of the operator were positively judged by IAEA and WENRA. In 1993 -Slovakia has accepted the commitments of the UN Convention on Climate Changes, including a reduction of greenhouse gases to 1990 levels by the year 2000. Moreover, as an internal target Slovakia has set the reaching of the ,'Toronto Objective', i.e. 20% reduction in CO x emissions through the year 2005 as compared to 1988. Taking into account the actual situation as well as natural conditions for some renewable sources utilisation, the target won't be reached without nuclear energy. The nuclear energy is free of emissions, does not burn oxygen, and with the share of production in Slovakia will remain significant contributor. To the environment protection it contributes also by replacing fossil heat plants with heat delivery for the region. In case of radiological wastes the environment protection is ensured by very strict system of control, evidence, treatment and repository. To conclude, Bohunice NPPs were, are and will remain very important part of the Slovak's economy, creating conditions for its (sustainable) development

  3. Operational experiences feedback in Bohunice NPP

    Energy Technology Data Exchange (ETDEWEB)

    Betak, A [NPP Bohunice (Slovakia)

    1997-10-01

    The presentation reviews the following issues: OEF team in Bohunice NPP - structure; training and qualification: ASSET seminars on Prevention of incidents - INES manual handling, NRA-NRC the training on event investigation methods, NU - the training on HPES; legislation - documentation prepared in the frame of QA programme; results of OEF team activities; ASSET mission Dukovany - Experiences; the perspective activities.

  4. NPP Bohunice experience with ASSET services

    International Nuclear Information System (INIS)

    Klimo, J.

    1996-01-01

    The general description of Bohunice NPP ASSET experience history was given at the last annual workshop in 1995. In my short presentation I would like to pay attention to the progress in this area which was achieved at our NPP during the last year. (author)

  5. NPP Bohunice experience with ASSET services

    Energy Technology Data Exchange (ETDEWEB)

    Klimo, J [Bohunice NPP (Slovakia)

    1997-12-31

    The general description of Bohunice NPP ASSET experience history was given at the last annual workshop in 1995. In my short presentation I would like to pay attention to the progress in this area which was achieved at our NPP during the last year. (author).

  6. Slovak Electric, plc, Bohunice Nuclear Power Plant

    International Nuclear Information System (INIS)

    1999-01-01

    A brief account of activities carried out by the Bohunice Nuclear Power Plant in 1998 is presented. These activities are reported under the headings: (1) Operation and electric power generation; (2) Nuclear and radiation safety; (3) Maintenance and scheduled refuelling out-gages; (4) Investment and WWER units upgrading; (5) Power Plants Personnel; (6) Public relations

  7. Radiological characterisation of V1 NPP technological systems and buildings - Activation

    International Nuclear Information System (INIS)

    Kristofova, Kristina; Rapant, Tibor; Svitek, Jaroslav

    2012-01-01

    V1 NPP at Jaslovske Bohunice site has been finally shutdown after 28 years of successful operation in 2006 (Unit 1) and 2008 (Unit 2). At present, both units are finally shutdown and since July 2011 under decommissioning license. The preparation of V1 NPP decommissioning has been supported and partly financed by the Bohunice International Decommissioning Support Fund (BIDSF), under the administration of the European Bank for Reconstruction and Development. From 06/2008 to 12/2011 AMEC Nuclear Slovakia, together with partners STM Power and EWN GmbH, carried out BIDSF B6.4 project - Decommissioning database development (DDB). The main purpose of the B6.4 project was to develop a physical and radiological inventory database to support V1 NPP decommissioning process planning and performance. One of the specific deliverable tasks within the B6.4 project was deliverable D12 - Characterization of activated equipment and civil structures based on measurement, sampling and analyses performed on the samples. The scope of deliverable services within D12 task consisted of: 1. Categorization of activated components ; 2. Development of single working programs for their radiological monitoring and sampling ; 3. Preparation of sampling device and revision of all handling equipment; 4. Dose rate monitoring and sampling of: - Civil structures from reactors shaft on both units ; - Components placed in HLW storage, (so called 'Mogilnik') - connection rods, absorbers ; of control rod assemblies and neutron flux measurement channels ; - Reactor pressure vessel and shielding assemblies at both units of V1 NPP, reactor; internals from Unit 2 of V1 NPP; 5. Analysis of samples ; 6. Determination of radiological inventory ; 7. Import of radiological data for activated components into DDB. During sampling, mainly remotely controlled sampling device and radiation resistant camera with LED lightening for visual checking of all performed activities was used. In total, 125 samples have been taken

  8. Gas-cooled reactor programs. Fuel-management positioning and accounting module: FUELMANG Version V1. 11, September 1981

    Energy Technology Data Exchange (ETDEWEB)

    Medlin, T.W.; Hill, K.L.; Johnson, G.L.; Jones, J.E.; Vondy, D.R.

    1982-01-01

    This report documents the code module FUELMANG for fuel management of a reactor. This code may be used to position fuel during the calculation of a reactor history, maintain a mass balance history of the fuel movement, and calculate the unit fuel cycle component of the electrical generation cost. In addition to handling fixed feed fuel without recycle, provision has been made for fuel recycle with various options applied to the recycled fuel. A continuous fueling option is also available with the code. A major edit produced by the code is a detailed summary of the mass balance history of the reactor and a fuel cost analysis of that mass balance history. This code is incorporated in the system containing the VENTURE diffusion theory neutronics code for routine use. Fuel movement according to prescribed instructions is performed without the access of additional user input data during the calculation of a reactor operating history. Local application has been primarily for analysis of the performance of gas-cooled thermal reactor core concepts.

  9. Gas-cooled reactor programs. Fuel-management positioning and accounting module: FUELMANG Version V1.11, September 1981

    International Nuclear Information System (INIS)

    Medlin, T.W.; Hill, K.L.; Johnson, G.L.; Jones, J.E.; Vondy, D.R.

    1982-01-01

    This report documents the code module FUELMANG for fuel management of a reactor. This code may be used to position fuel during the calculation of a reactor history, maintain a mass balance history of the fuel movement, and calculate the unit fuel cycle component of the electrical generation cost. In addition to handling fixed feed fuel without recycle, provision has been made for fuel recycle with various options applied to the recycled fuel. A continuous fueling option is also available with the code. A major edit produced by the code is a detailed summary of the mass balance history of the reactor and a fuel cost analysis of that mass balance history. This code is incorporated in the system containing the VENTURE diffusion theory neutronics code for routine use. Fuel movement according to prescribed instructions is performed without the access of additional user input data during the calculation of a reactor operating history. Local application has been primarily for analysis of the performance of gas-cooled thermal reactor core concepts

  10. Project Management Unit for decommissioning of NPP Bohunice VI (2003-2014)

    International Nuclear Information System (INIS)

    Gonzalez Fernandez-conde, A.; Brochet, I.; Ferreira, A.

    2015-01-01

    From October 2003 until december 2014 the Consortium consisting of Iberdrola Engineering and Construction (leader). Empresarios Agrupados Internacional, and Indra Sistemas has carried out the project Project Management Unit ((PMU) for the decommissioning of Bohunice V1 NPP (units 1 and 2), type VVER-440/V-230 in Slovakia. during the first phase (2003-2007) EdF was also part of the Consortium. The project is funded by the Bohunice International Decommissioning Support Fund (BIDSF) administered by the RBRD. The main objective of the project is to provide the necessary engineering and resources of project management for planning, execution, management, coordination and monitoring of all tasks in support of the decommissioning. (Author)

  11. Twenty years of operation of WWER 440/230 units in Jaslovske Bohunice

    International Nuclear Information System (INIS)

    Tomek, J.

    1998-01-01

    It is twenty years this year since the first unit WWER 440 of Slovak Nuclear Power Plant Jaslovske Bohunice was commissioned. There are four units WWER 440 in operation Jaslovske Bohunice site. First two units of older soviet PWR design V-230 (also known as V-1) and other two units of newer V-213 type (also known as V-2). The goal of this presentation is to summarize and evaluate the operation of Unit 1 and 2 for this period of time and mainly to describe what has been done and what is planned to be done to increase the nuclear safety and operational reliability of both units. The operating organization and regulatory authority assume that an internationally acceptable level of safety will be reached by accomplishing of the upgrading program.(author)

  12. Evolution of ASTEC V1.2 rev.1 code for WWER-1000 reactors/SBO sequence

    International Nuclear Information System (INIS)

    Georgieva, J.; Stefanova, A.; Groudev, P.; Tusheva, P.; Kalchev, B.; Passalacqua, R.

    2006-01-01

    In this paper a comparison between calculations of severe accidents occurred from WWER-1000 with ASTEC code specified for an event of full unloading with relief valves stuck opened with no hydroaccumulators intervention is presented. The purpose of the analyses provided is to present the relationship between the improvements of the actual version (ASTEC Vl.2 rev. 1) and ASTEC V1.1 p2 like: code modifications, incoming data improvements. Such discrepancies are to be examined. Case by case suggestions for ASTEC improvements are to be provided

  13. TEMPERA-V2. A computer program for sensitivity analysis in a cooling channel of nuclear reactors-V.1

    International Nuclear Information System (INIS)

    Andrade Lima, F.R. de; Alvim, A.C.M.

    1986-09-01

    The sensitivity of linear responses associated with physical quantities governed by non linear differential systems is studied, using perturbation theory. The equivalence and formal differences of differential and GPT formalisms are shown. Both of them and also the matricial formalism are used for sensitivity calculations of transient problems in a typical PWR coolant channel. The results obtained are encouraging with respect to the potentiality of the method for thermal-hydraulic calculations normally performed for reactor design and safety analysis. (Author) [pt

  14. Personnel education and training at Bohunice NPP

    International Nuclear Information System (INIS)

    Malovec, J.

    1998-01-01

    Procedure for education and training of all the personnel employed at Bohunice Nuclear power plant is presented in detail describing the training system structure, kinds of training, staff members qualification development, short term and long term tasks needed to assure attaining the training objectives. The proposed Staff Members Lifetime education implementation project contains basic starting points, measures to be implemented by 1998. It was prepared on the basis of a primary analysis which confirmed the existing need for implementing the lifetime education system

  15. ESTE EMO and ESTE EBO - emergency response system for NPP Mochovce and NPP Bohunice V-2

    International Nuclear Information System (INIS)

    Caeny, P.; Chyly, M.; Suchon, D.; Smejkalova, E.; Fabova, V.; Mancikova, M.; Muller, P.

    2009-01-01

    Programs ESTE EMO and ESTE EBO are emergency response systems that help the crisis staff of the NPP in assessing the source term (predicted possible release of radionuclides to the atmosphere ), in assessing the urgent protective measures and sectors under threat, in assessing real release (symptoms of release really detected and observed), in calculating radiological impacts of real release, averted or avertable doses, potential doses and doses during transport or evacuation on specified routes. Both systems serve as instruments in case of severe accident (DBA or BDBA) at NPP Mochovce or NPP Bohunice, accidents with threat of release of radioactivity to the atmosphere. Systems are implemented at emergency centre of Mochovce NPP and Bohunice NPP and connected online to the sources of technological and radiological data from the reactor, primary circuit, confinement, secondary circuit, ventilation stack, from the area of NPP (TDS 1) and from the emergency planning zone (TDS 11). Systems are connected online to the sources of meteorological data, too. (authors)

  16. ESTE EMO and ESTE EBO - emergency response system for NPP Mochovce and NPP Bohunice V-2

    International Nuclear Information System (INIS)

    Caeny, P.; Chyly, M.; Suchon, D.; Smejkalova, E.; Fabova, V.; Mancikova, M.; Muller, P.

    2008-01-01

    Programs ESTE EMO and ESTE EBO are emergency response systems that help the crisis staff of the NPP in assessing the source term (predicted possible release of radionuclides to the atmosphere ), in assessing the urgent protective measures and sectors under threat, in assessing real release (symptoms of release really detected and observed), in calculating radiological impacts of real release, averted or avertable doses, potential doses and doses during transport or evacuation on specified routes. Both systems serve as instruments in case of severe accident (DBA or BDBA) at NPP Mochovce or NPP Bohunice, accidents with threat of release of radioactivity to the atmosphere. Systems are implemented at emergency centre of Mochovce NPP and Bohunice NPP and connected online to the sources of technological and radiological data from the reactor, primary circuit, confinement, secondary circuit, ventilation stack, from the area of NPP (TDS 1) and from the emergency planning zone (TDS 11). Systems are connected online to the sources of meteorological data, too. (authors)

  17. The V-1 NPP and V-2 NPP upgrading

    International Nuclear Information System (INIS)

    1998-01-01

    A brief account of activities in the V-1 NPP and V-2 NPP upgrading as well as maintenance carried out by the Nuclear power plants Jaslovske Bohunice in 1997 is presented. The V-1 NPP applied the so called 'Small Backfitting Programme'covering 81 points of the Czechoslovak Atomic energy Commission Decree No 5/91. Continual upgrading continued after the Backfitting Programme completion with the Safety Report and following Nuclear Regulatory Authority of Slovak Republic (NRA SR) Decrees No 1/94 and 110/94 setting spheres and procedure for adopting and implementation of measures enabling the units to operate further on. Results of expert missions, analyses and assessments of components identified by Basic Engineering became the basis for the development of the Gradual Reconstruction Programme. The Programme outputs underwent economic and probabilistic assessing their contribution to nuclear safety. This process resulted in finalizing the Gradual Reconstruction Programme which started to be implemented in 1996 and will be completed in 1999. It is implemented by the REKON consortium and covers 17 areas including Instrumentation and Control, self-consumption emergency supply, leakage monitoring, emergency core cooling system, seismic reinforcement and radioactivity localisation. Both units will reach internationally acceptable safety standards for the remaining life-time period. The V-2 NPP Upgrading and Safety Enhancement Programme includes results of activities performed in the course of last years to define all important activities leading to enhancement of nuclear safety and performance reliability and effectiveness within the plant life-time period and to establish conditions for extending the life-time of these units for 40 years. The V-2 NPP Upgrading and Safety Enhancement Programme aims to assure safe operation with a probability of the core damages less than 10 -4 /reactor · year

  18. The Modernization Program and Power Up-rate at NPP V2 Jaslovske Bohunice, Slovak Republic

    International Nuclear Information System (INIS)

    Reznik, Vladivoj; Krajmer, Imrich

    2010-01-01

    Slovenske Elektrarne, a.s. is a second largest utility company in the Central and Eastern Europe that owns an optimal production portfolio comprised of nuclear, thermal and hydroelectric power plants. There are two nuclear power plants Bohunice and Mochovce both operate with two units and another two units Mochovce 3 and 4 are currently under construction. Electricity at Nuclear power plant Bohunice V2 is generated by two 440 MW units that had gradually been connected to the power network over the period between 1984 and 1985. In the construction of the nuclear power plant V2 the concept of pressurized water reactors was adopted and the Soviet-era design WWER 440 used. The upgrading of Nuclear Power Plant Bohunice V2 is based on three main points: Modernization, Power up-rate, and Ageing monitoring program. The main targets of the modernization project were: Increasing of the Nuclear Safety and of the Nuclear operational reliability, and Seismic improvement. This modernization program is in full compliance with IAEA requirements and with the decisions from the Nuclear Regulatory Agency of the Slovak Republic (UJD) and achievement of the probabilistic safety criteria in accordance with IAEA recommendations. Except that is ensured a safe, reliable, economical and effective electricity and heat generation. Achieved results are based for further prolongation of the operation life time up to 60 years. (authors)

  19. Forty years of atmospheric radiocarbon monitoring around Bohunice nuclear power plant, Slovakia

    International Nuclear Information System (INIS)

    Povinec, P.P.; Chudy, M.; Sivo, A.; Simon, J.; Holy, K.; Richtarikova, M.

    2009-01-01

    Radiocarbon variations in the atmospheric CO 2 with attenuating amplitudes and decreasing mean values with typical maxima in summer and minima in winter have been observed since 1967 in two localities of Slovakia, in Bratislava and Zlkovce, situated about 60 km NE from Bratislava, only 5 km from the Bohunice Nuclear Power Plant (NPP). The 14 C record in Bratislava has been influenced mainly by fossil CO 2 emissions, in contrast to the Zlkovce record which has been more variable, as it has clearly been affected by operation of the Bohunice NPP. However, during specific meteorological conditions with NE transport of air masses to Bratislava, the effect of the Bohunice NPP has been visible in Bratislava as well. Maximum 14 C concentrations (up to 120% above a natural background) were observed around A1 NPP which used CO 2 with admixture of air as a cooling agent. The 14 C concentrations around four pressurized light water reactors were up to 30% above the background. The Δ 14 C values in the heavily polluted atmosphere of Bratislava were up to 10% and at Zlkovce up to 5% lower than the European clean air represented by the Jungfraujoch Δ 14 C data. Later the Δ 14 C values were similar at both sites, and from 2003 they were close to the European clean air levels. The observed Δ 14 C behaviour in the atmosphere provides a unique evidence of decreased fossil fuel CO 2 emissions in the region, as well as the long-term effect of the Bohunice NPP on the Bratislava and Zlkovce stations. The estimated annual radiation doses to the local public due to digestion of radiocarbon contaminated food have been estimated to be around 3 μSv

  20. Mitsubishi nuclear technologies and construction of new Bohunice

    International Nuclear Information System (INIS)

    Yoshizu, T.

    2009-01-01

    Mitsubishi Heavy Industries (MHI) has setup Generation III+ category power plant technologies both in large and middle size reactors as a key player in the global market of nuclear plant suppliers. MHI has developed 1,700 MWe class Advanced Pressurized Water Reactor for European utilities, EU-APWR, utilizing the APWR technology in Japan. The plant configuration is based on the proven technologies from MHI's ample experiences, but various advanced technologies are adopted to achieve enhanced safety, reliability, and economy. For the regions without large grid capacity, middle-sized nuclear power plant will be an attractive option for the utilities. Joint Venture ATMEA with AREVA NP will serve ATMEA1. The ATMEA1 will offer 1,100 MWe output with superior operation performance based on reliable and proven technologies. Mitsubishi has experience of half century for all of 26 PWR plants in Japan. The latest plant is Tomari Unit 3 of 1,000 MWe, which has completed the construction work and now in the final commissioning test. Tomari Unit 3 applies some advanced technologies such as all digital I and C, which are to be implemented in the EU-APWR. Based on this construction experience, Mitsubishi can contribute any kind of demands for New Bohunice 5 th unit project with the total engineering capability. (author)

  1. Long-term measurement with calorimetric probes at unit 1 of V-1 nuclear power plant

    International Nuclear Information System (INIS)

    Erben, O.; Szasz, Z.; Jirousek, V.; Teren, S.

    1989-01-01

    Two calorimetric probes were tested at the first unit of the Bohunice V-1 nuclear power plant in long-term operation, i.e., during one whole reactor duty time. Each probe consisted of five fission calorimeters and one compensation calorimeter with a tungsten body. The actual calorimeters were provided with jacketed thermocouples 0.5 mm indiameter and 19 m in length. A detailed description is presented of the measuring chains and measurement techniques. Also described is the method of the disposal of the irradiated probes. The method is presented of the evaluation of measured data and the results are discussed of the analysis of these data. The measurements, including measurements during reactor shut-down and the results of the analysis of the measured data proved good viability and stability of the used calorimetres. The method of measuring the thermocouple signals is simple and the in-service evaluation of required data is quick. In order to increase measurement efficiency it would be appropriate to complete the measuring chain and to automate it. Reliability is a affected merely by protecting the thermocouples against mechanical damage during measurement probe handling and on the reactor. (Z.M.). 5 figs., 5 tabs., 5 refs

  2. Comparison and validation of the results of the AZNHEX v.1.0 code with the MCNP code simulating the core of a fast reactor cooled with sodium

    International Nuclear Information System (INIS)

    Galicia A, J.; Francois L, J. L.; Bastida O, G. E.; Esquivel E, J.

    2016-09-01

    The development of the AZTLAN platform for the analysis and design of nuclear reactors is led by Instituto Nacional de Investigaciones Nucleares (ININ) and divided into four working groups, which have well-defined activities to achieve significant progress in this project individually and jointly. Within these working groups is the users group, whose main task is to use the codes that make up the AZTLAN platform to provide feedback to the developers, and in this way to make the final versions of the codes are efficient and at the same time reliable and easy to understand. In this paper we present the results provided by the AZNHEX v.1.0 code when simulating the core of a fast reactor cooled with sodium at steady state. The validation of these results is a fundamental part of the platform development and responsibility of the users group, so in this research the results obtained with AZNHEX are compared and analyzed with those provided by the Monte Carlo code MCNP-5, software worldwide used and recognized. A description of the methodology used with MCNP-5 is also presented for the calculation of the interest variables and the difference that is obtained with respect to the calculated with AZNHEX. (Author)

  3. Practical experience with the leaky-fuel monitoring at Bohunice NPP

    International Nuclear Information System (INIS)

    Kacmar, M.; Cizek, J.

    2001-01-01

    The first part of this paper describes practical experience with the fuel monitoring in operating reactors from point of view possible leakages. Summarized in the paper are numbers leaky fuel assemblies both for NPP and for particular units. Some failure causes are discussed for operational conditions of Bohunice NPP. In the second part of paper critical power ramps on hot fuel rod of leaky fuel assemblies are analysed to eliminate failures from PCI. The main aim of the paper is the need to understand the mechanism and causes of failures (Authors)

  4. Experiences from start-up and use of fail-safe reactor level meter with KNITU probes

    International Nuclear Information System (INIS)

    Badiar, S.; Sipka, J.; Vanco, P.; Slanina, Marek; Liska, L.; Gavora, D.

    2001-01-01

    Within the framework of the reconstruction of both V1 Bohunice units with WWER-440/V-230 reactors, the VUJE-SIEMENS consortium implemented measurement systems for coolant level monitoring in reactor pressure vessels with 1E qualification, resp. with the qualification of category 1 according to NUSS RG1.97. The solution uses KNITU 11 probes made by Russian POZIT company. In operating plants, the installation causes problems in relation to the existing technology and quality assurance system. In the phase of implementation, the most important tasks were to resolve component quality, to commission the system, and to check its performance. (Authors)

  5. Radiation supervision - NPPs A-1, V-1, V-2

    International Nuclear Information System (INIS)

    2000-01-01

    In this leaflet the radiation supervision of the nuclear power plants A-1, V-1, V-2 is presented. Off-site radiation supervision laboratory is a part of monitoring scheme of the NPPs. More than 1150 samples are taken from the environment annually. The tele-dosimetric system was constructed to improve the quality of the Bohunice NPPs operation impacts supervision. It has been running in a continuous operation from 1992 and providing supervision of the nuclear power plant off-site area within 25 kilometres. The tele-dosimetric system is described

  6. The most extensive reconstruction of nuclear power plant with VVER 440/V230 reactor

    International Nuclear Information System (INIS)

    Ferenc, M.

    2000-01-01

    The nuclear power plant V-1 Bohunice consists of two VVER-440 units with V-230 reactors. Unit 1 was commissioned in 1978 and Unit 2 in 1980. Large experience and knowledge from the operation of previous units with V-230 reactors were incorporated into the V-1 design, which resulted in a higher level of safety and operational reliability of these units. The Siemens company which won an international bidding process developed these basic goals for the Gradual Upgrading into the so called Basic Engineering (BE). For the implementation of the Gradual Upgrading in line with the BE, Rekon consortium was established consisting of Siemens and VUJE. The implementation of the Gradual Upgrading is scheduled for the time period of 1996 - 2000. Siemens was responsible for the upgrading strategy - based on the approved results of the basic engineering phase and the PSAR, the engineering and realization of all I and C improvements, and also for the seismic upgrade. VUJE's responsibility covered the detailed engineering and implementation of mechanical, electrical and civil part of upgrading measures as well as overall organisation and evaluation of verification tests. The consortium awarded contracts for final planning and design, installation services and commissioning to other Slovakian subcontractors in order to ensure the largest possible local content. The gradual reconstruction of the V-1 Bohunice with V230 reactors represents a comprehensive reconstruction of safety-related systems and equipment. Following its completion, the units will be operated with a safety level accepted internationally. (author)

  7. Information letter 2. Information about operation of plants SE-NPP Bohunice and SE-VYZ during February 2005

    International Nuclear Information System (INIS)

    2005-03-01

    In this leaflet results of exploitation of four units of the Bohunice V-1 and V-2 NPPs are presented. The electricity and heat production in February 2005 are reviewed. Within a February 2005 the electricity was produced: 217 GWh (block 1), 281 GWh (block 2), 277 GWh (block 3), 282 GWh (block 4), totally 1057 GWh, and 2271 GWh within a January - February 2005. The heat production in February 2005 was 266 506 GJ, and within a January - February 2005 it was produced 531 849 GJ of heat. On February 17 Slovak minister of economy Pavol Rusko and general director of ENEL Paolo Scaroni signed the agreement on acquisition of 66 per cent of Slovenske elektrarne (SE) by Italian ENEL for 840 million Eur. SE has capacity of around 7 GW (83 per cent of total Slovakian capacity). In 2004 SE generated 26 TWh of electricity. Processing and storage of radioactive wastes in Decommissioning of Nuclear Installations and Spent Fuel and Rad-waste Management (SE-VYZ) is presented. Since beginning of this year 58 fibre-concrete containers have been filled up in Bohunice processing centre of radioactive wastes. Twenty-three pieces of fibre-concrete containers were processed into fibre-concrete containers in Bohunice processing centre of radioactive wastes (BSC RAO) in February 2005. Twenty fibre-concrete containers were stored into Republic storage of radioactive wastes (RU RAO). Total number in RU RAO reached 830 pieces of fibre-concrete containers, which represent 11.53 per cent of storage capacity (7200 containers). Bohunice processing centre of radioactive wastes was put into active operation just before five years

  8. Comparison and validation of the results of the AZNHEX v.1.0 code with the MCNP code simulating the core of a fast reactor cooled with sodium; Comparacion y validacion de los resultados del codigo AZNHEX v.1.0 con el codigo MCNP simulando el nucleo de un reactor rapido refrigerado con sodio

    Energy Technology Data Exchange (ETDEWEB)

    Galicia A, J.; Francois L, J. L.; Bastida O, G. E. [UNAM, Facultad de Ingenieria, Departamento de Sistemas Energeticos, Ciudad Universitaria, 04510 Ciudad de Mexico (Mexico); Esquivel E, J., E-mail: blink19871@hotmail.com [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2016-09-15

    The development of the AZTLAN platform for the analysis and design of nuclear reactors is led by Instituto Nacional de Investigaciones Nucleares (ININ) and divided into four working groups, which have well-defined activities to achieve significant progress in this project individually and jointly. Within these working groups is the users group, whose main task is to use the codes that make up the AZTLAN platform to provide feedback to the developers, and in this way to make the final versions of the codes are efficient and at the same time reliable and easy to understand. In this paper we present the results provided by the AZNHEX v.1.0 code when simulating the core of a fast reactor cooled with sodium at steady state. The validation of these results is a fundamental part of the platform development and responsibility of the users group, so in this research the results obtained with AZNHEX are compared and analyzed with those provided by the Monte Carlo code MCNP-5, software worldwide used and recognized. A description of the methodology used with MCNP-5 is also presented for the calculation of the interest variables and the difference that is obtained with respect to the calculated with AZNHEX. (Author)

  9. Proceedings of the GCNEP-IAEA course on natural circulation phenomena and passive safety systems in advanced water cooled reactors. V.1

    International Nuclear Information System (INIS)

    2014-01-01

    The current status and prospect, economics, advanced designs and applications of reactors in operation and construction, safety of advanced water cooled reactors is discussed. Papers relevant to INIS are indexed separately

  10. Upgrading of the radiation protection system at the V1 NPP

    International Nuclear Information System (INIS)

    Dobis, L.; Kaizer, J.; Svitek, J.

    2003-01-01

    The original radiation protection system at Bohunice V1 NPP from the 1970s was upgraded so as to meet current national as well as international standards. The article describes the upgrading of the radiation control system (teledosimetry, emergency measurement in the hermetic zone, liquid discharges, gaseous discharges, service water, remote measurement, hygiene loop, contamination monitoring at the controlled zone exit and activity monitoring at the NPP exit, special laundry, instrument calibration), dosimetry, software, and personnel contamination inspection/measurement. (author)

  11. Preparation for and building of V-1 nuclear power plant

    International Nuclear Information System (INIS)

    Smatlak, S.; Spirko, M.

    1981-01-01

    Some findings and problems encountered during the construction of the V-1 nuclear power plant at Jaslovske Bohunice are discussed from the point of view of the investor, mainly problems associated with project preparation and relations between suppliers and the customer. The progress of construction is described and the dates are shown of the main stages of construction and tests. The construction proceeded according to a net diagram and was controlled by the construction management and a coordination group headed by the investor. An international start-up commission was established for the start-up stage. The fields are outlined of the participation and co-operation of Soviet organizations during project preparation, supplies, assembly, start-up, and fuel supplies for the V-1 nuclear power plant. (B.S.)

  12. Termination of exploitation of V 1 NPP - BIDSF projects

    International Nuclear Information System (INIS)

    Pnackova, L.

    2004-01-01

    In this paper the interview with engineer Peter Hlbocky, director of division of the Project of decommissioning of V 1 Nuclear Power Plant in Jaslovske Bohunice is presented. Project Manager Unit (PMU) was formed on the basis of directive of the General Director of the Slovenske elektrarne, a.s. The Director of the Division of decommissioning of the V 1 NPP and at the same time the Main manager of the PMU is engineer Peter Hlbocky. On this project participate 19 employees of the Slovenske elektrarne, a. s. (SE), 6 abroad employees of the consortium IBERINCO, 15 employees of the VUEZ and 25 abroad employees on the detached place of work in the Spain and France

  13. Risk-informed decision making during Bohunice NPP safety upgrading

    International Nuclear Information System (INIS)

    Lipar, M.; Muzikova, E.; Kubanyi, J.

    2001-01-01

    The paper summarizes some facts of risk-informed regulation developments within UJD regulatory environment. Based on national as well as international operating experience and indications resulted from PSA, Nuclear Regulatory Authority of the Slovak Republic (UJD) since its constituting in 1993 has devoted an effort to use PSA technology to support the regulatory policy in Slovakia. The PSA is considered a complement, not a substitute, to the deterministic approach. Suchlike integrated approach is used in decision making processes and the final decision on scope and priorities is based on it. The paper outlines risk insights used in the decision making process concerning Bohunice NPP safety upgrading and focuses on the role of PSA results in Gradual Reconstruction of Bohunice VI NPP. Besides, two other examples of the PSA results application to the decision making process are provided: the assessment of proposal of modifications to the main power supply diagram (incorporation of generator switches) and the assessment of licensee request for motor generator AOT (Allowable Outage Time) extension. As an example of improving support of Bohunice V-2 risk-informed operations, concept of AOT calculations and Bohunice V-2 Risk Monitor Project are briefly described. (author)

  14. Fuel utilization experience in Bohunice NPP and regulatory requirements for implementation of progressive fuel management strategies

    Energy Technology Data Exchange (ETDEWEB)

    Patenyi, V [Nuclear Regulatory Authority, Bratislava (Slovakia); Darilek, P; Majercik, J [Vyskumny Ustav Jadrovych Elektrarni, Trnava (Slovakia)

    1994-12-31

    The experience gained in fuel utilization and the basic requirements for fuel licensing in the Slovak NPPs is described. The original project of WWER-440 reactors supposes 3-year fuel cycle with cycle length of about 320 full power days (FPD). Since 1984 it was reduced to 290 FPD. Based on the experience of other countries, a 4-year fuel cycle utilization started in 1987. It is illustrated with data from the Bohunice NPP units. Among 504 fuel assemblies left for the fourth burnup cycle no leakage was observed. The mean burnup achieved in the different units varied from 33.1 to 38.5 Mwd/kg U. The new fuel assemblies used are different from the recent ones in construction, thermohydraulics, water-uranium ratio, enrichment and material design. To meet the safety criteria, regulatory requirements for exploitation of new fuel in WWER-440 were formulated by the Nuclear Regulatory Authority of Slovak Republic. 1 tab., 5 refs.

  15. The results of the surveillance specimen program performed in the RPVs NPP V-2 in Jaslovske Bohunice

    Energy Technology Data Exchange (ETDEWEB)

    Kupca, L; Beno, P [Vyskumny Ustav Jadrovych Elektrarni, Trnava (Slovakia); Cepeek, S [Atomova Elektraren Bohunice, Jaslovske Bohunice (Slovakia); Tomasich, M [Slovak Nuclear Society, Bratislava (Slovakia)

    1994-12-31

    After a description of the mechanical and chemical characteristics of the materials (steels, welded joints) used in the pressure vessels of the WWER-440 V-213 type, the present status of the Bohunice NPP Unit 3 and 4 pressure vessel embrittlement assessment programme is presented: neutron flux monitoring and calculations, detector accuracy, irradiation temperature monitoring, reactor core fuel loading calculation, materials, number and types of surveillance specimens, specimen testing. Results are given for 5 years of irradiation: mechanical properties, transition temperatures, lifetime evaluation. 4 refs., 13 figs., 6 tabs.

  16. Reactor cooling systems thermal-hydraulic assessment of the ASTEC V1.3 code in support of the French IRSN PSA-2 on the 1300 MWe PWRs

    International Nuclear Information System (INIS)

    Tregoures, Nicolas; Philippot, Marc; Foucher, Laurent; Guillard, Gaetan; Fleurot, Joelle

    2010-01-01

    The French Institut de Radioprotection et de Surete Nucleaire (IRSN) is performing a level 2 Probabilistic Safety Assessment (PSA-2) on the French 1300 MWe PWRs. This PSA-2 study is relying on the ASTEC integral computer code, jointly developed by IRSN and GRS (Germany). In order to assess the reliability and the quality of physical results of the ASTEC V1.3 code as well as the PWR 1300 MWe reference input deck, a wide-ranging series of comparisons with the French best-estimate thermal-hydraulic code CATHARE 2 V2.5 has been performed on 14 different severe-accident scenarios. The present paper details 4 out of the 14 studied scenarios: a 12-in. cold leg Loss of Coolant Accident (LOCA), a 2-tube Steam Generator Tube Rupture (SGTR), a 12-in. Steam Line Break (SLB) and a total Loss of Feed Water scenario (LFW). The thermal-hydraulic behavior of the primary and secondary circuits is thoroughly investigated and compared to the CATAHRE 2 V2.5 results. The ASTEC results of the core degradation phase are also presented. Overall, the thermal-hydraulic behavior given by the ASTEC V1.3 is in very good agreement with the CATHARE 2 V2.5 results.

  17. Fuel leak testing performance at NPP Jaslovske Bohunice

    International Nuclear Information System (INIS)

    Slugen, V.; Krnac, S.; Smiesko, I.

    1995-01-01

    The NPP Bohunice VVER-440 fuel leak testing experience are relatively extensive in comparison with other VVER-440 users. As the first Europe NPP was adapted Siemens (KWU) in core-sipping equipment to VVER-440 units and since this time were have done these tests also for NPP Paks (Hungary) and NPP Dukovany (Czech Republic). The occurrence of leaking fuel assemblies in NPP is in the last 5 years relatively stabilised and low. A significant difference can be observed between type V-230 (31 leaks) and type V-213 (1 leak). None of of the indicated leaking fuel assemblies has been investigated in the hot cell. Therefore cannot be confirm the effective causes of leak occurrence. Nevertheless, the fuel failure rate and the performance of leak testing in NPP Bohunice are comparable to the world standard at PWR's. 1 tab., 2 figs., 3 refs

  18. Fuel leak testing performance at NPP Jaslovske Bohunice

    Energy Technology Data Exchange (ETDEWEB)

    Slugen, V; Krnac, S [Slovak Technical Univ., Bratislava (Slovakia); Smiesko, I [Nuclear Powr Plant EBO, Jaslovske Bohuce (Slovakia)

    1996-12-31

    The NPP Bohunice VVER-440 fuel leak testing experience are relatively extensive in comparison with other VVER-440 users. As the first Europe NPP was adapted Siemens (KWU) in core-sipping equipment to VVER-440 units and since this time were have done these tests also for NPP Paks (Hungary) and NPP Dukovany (Czech Republic). The occurrence of leaking fuel assemblies in NPP is in the last 5 years relatively stabilised and low. A significant difference can be observed between type V-230 (31 leaks) and type V-213 (1 leak). None of of the indicated leaking fuel assemblies has been investigated in the hot cell. Therefore cannot be confirm the effective causes of leak occurrence. Nevertheless, the fuel failure rate and the performance of leak testing in NPP Bohunice are comparable to the world standard at PWR`s. 1 tab., 2 figs., 3 refs.

  19. Management of the Bohunice RPVs annealing procedures

    International Nuclear Information System (INIS)

    Repka, M.

    1994-01-01

    The program of annealing regeneration procedure of RPVs units 1 and 2 of NPP V-1 (EBO) realization in the year 1993, is the topic of this paper. In the paper the following steps are described in detail: the preparation works, the annealing procedure realization schedule and safety management: starting with zero conditions, assembling of annealing apparatus, annealing procedure, cooling down and disassembling procedure of annealing apparatus. At the end the programs of annealing of both RPVs including the dosimetry measurements are discussed and evaluated. (author). 3 figs

  20. Heat transfer. V. 1

    International Nuclear Information System (INIS)

    1992-01-01

    This volume contains the 4 key-note lectures and 83 of the 148 papers presented at the 3rd UK National Conference on Heat Transfer. The papers are grouped under the following broad headings: boiling and condensation; heat exchangers; refrigeration and air-conditioning; natural convection; process safety and nuclear reactors; two-phase flow; post dry-out; combustion, radiation and chemical reaction. Separate abstracts have been prepared for 13 papers of relevance to nuclear reactors. (UK)

  1. Information letter 3. Information about operation of plants SE-NPP Bohunice and SE-VYZ during March 2006

    International Nuclear Information System (INIS)

    2006-04-01

    In this leaflet results of exploitation of four units of the Bohunice V-1 and V-2 NPPs are presented. The electricity and heat production in March 2006 are reviewed. Within a March 2006 the electricity was produced: 294.020 GWh (block 1), 287.684 GWh (block 2), 292.636 GWh (block 3), 237.806 GWh (block 4), totally 1112 GWh, and 3330 GWh within a January - March 2005. The heat production in January 2006 was 253 057 GJ, and within a January - March 2006 it was produced 896 226 GJ of heat. Processing and storage of radioactive wastes in Decommissioning of Nuclear Installations and Spent Fuel and Rad-waste Management (SE-VYZ) is presented. Twenty-one pieces of fibre-concrete containers were processed into fibre-concrete containers in Bohunice processing centre of radioactive wastes (BSC RAO) in March 2006. Sixteen fibre-concrete containers were stored into Republic storage of radioactive wastes (RU RAO). Total number in RU RAO reached 1080 pieces of fibre-concrete containers, which represent 15.00 per cent of storage capacity (7200 containers). Celebration of ten years operation of SE-VYZ is described

  2. Information letter 1. Information about operation of plants SE-NPP Bohunice and SE-VYZ during January 2006

    International Nuclear Information System (INIS)

    2006-02-01

    In this leaflet results of exploitation of four units of the Bohunice V-1 and V-2 NPPs are presented. The electricity and heat production in January 2006 are reviewed. Within a January 2006 the electricity was produced: 249.149 GWh (block 1), 293.272 GWh (block 2), 305.479 GWh (block 3), 308.378 GWh (block 4), totally 1156 GWh. The heat production in January 2006 was 354 397 GJ. Processing and storage of radioactive wastes in Decommissioning of Nuclear Installations and Spent Fuel and Rad-waste Management (SE-VYZ) is presented. Twenty-two pieces of fibre-concrete containers were processed into fibre-concrete containers in Bohunice processing centre of radioactive wastes (BSC RAO) in January 2006. Sixteen fibre-concrete containers were stored into Republic storage of radioactive wastes (RU RAO). Total number in RU RAO reached 1048 pieces of fibre-concrete containers, which represent 14.55 per cent of storage capacity (7200 containers)

  3. Recent events at Bohunice NPP Slovak Republic

    International Nuclear Information System (INIS)

    Lipar, M.

    1996-01-01

    During a filter regeneration in the steam generators (SG) blow down purification system at full power, approximately 900 litres of NaOH penetrated through a condensate collection tank into the main turbine condenser and subsequently into three SGs. The penetration occurred because of a valve left open during the filter regeneration due to a valve configuration error. The water in the tree SGs foamed, causing unexpected behaviour in SG level indicators which led to a reactor scram. By exceeding the pH value of feedwater for 7 minutes, the technical specification were violated, until the unit was brought into hot shut-down mode. Figs

  4. Experience with humidity monitoring and leak detection system SMU-V at the Jaslovske Bohunice V-1 NPP

    International Nuclear Information System (INIS)

    Macko, O.

    1996-01-01

    Within the paper a brief technical description of SMU-V system is presented including algorithms for measured data evaluation, assessment of experience acquired the system operation and prospective VUEZ activities aimed at the developed of systems for NPP primary circuit leak detection based on humidity monitoring. System SMU-V is used to diagnose dangerous conditions during which integrity of the pipeline could be impaired resulting in absolute humidity increase in the monitored volume. (author)

  5. Eco information 9. Influence of operation of the plants Jadrova vyradovacia spolocnost, a.s., on the environment, locality of Bohunice, within September 2014

    International Nuclear Information System (INIS)

    2014-10-01

    In this leaflet the results of monitoring of chemical gaseous and liquid effluents into the rivers Vah and Dudvah as well as of radiation monitoring of Bohunice V1 NPP, Interim Spent Fuel Storage (MSVP), Bohunice Radioactive Waste Processing Centre (VK808 - BSC), The Main Production Unit (VK 46A - HVB) and Bitumenation Lines (VK 46B - BL) are presented. The radioactive effluents into atmosphere within January - September 2014 (for NPP V1, MSVP, BSC, HVB and BL, respectively) were: 1.483 MBq (0.002 of AL) for V1, 0.087 MBq (0.029% of AL) for MSVP, 0.084 MBq (0.060% of AL) for BSC, 0.400 MBq (0.061% of AL) for HVB and 0.028 MBq (0.020% of AL) for BL of aero-soles. The radioactive effluents into atmosphere and hydrosphere within a September 2014 for NPP V1, MSVP, and VK 808 BSC, respectively, were: 0.258 MBq (V1), 0.007 MBq (VK MSVP), 0.018 MBq (VK 808 BSC), 0.005 MBq (VK 46A) and 0.002 MBq (VK 46B) of aero-soles into atmosphere; 1.169 MBq (V1 and MSVP) and 0.522 MBq (TSU RAO and NPP A1) of corrosive and fission products, and 0.002 GBq (V1 and MSVP) and 16.740 GBq (TSU RAO and NPP A1) of tritium into the Vah River and 0.000 GBq (V1 and MSVP) and 0.000 MBq (TSU RAO and NPP A1) of corrosive and fission products and 0.000 GBq of tritium (V1) and 0.000 GBq of tritium (TSU RAO and NPP A1) into the Dudvah River). For the period January - September 2014 these radioactive effluents into recipient of Vah River represent for corrosive and fission products 12.402 MBq (0.095% of AL for V1 and MSVP) and 5.010 MBq (0.042% of AL for TSU RAO and MSVP); and for tritium it is 8.382 GBq (0.419% of AL) for V1 and MSVP, and 98.415 GBq (0.984% of AL) for TSU RAO and NPP A1 (into the Vah River) and for corrosive and fission products 0.000 MBq (V1 and MSVP) and 0.000 MBq (TSU RAO and NPP A1) (0.0000 of AL) of tritium (into the Dudvah River). Chemical effluents are reported, too.

  6. Eco information 1. Influence of operation of the plants Jadrova vyradovacia spolocnost, a.s., on the environment, locality of Bohunice, within January 2016

    International Nuclear Information System (INIS)

    2016-02-01

    In this leaflet the results of monitoring of chemical gaseous and liquid effluents into the rivers Vah and Dudvah as well as of radiation monitoring of Bohunice V1 NPP, Interim Spent Fuel Storage (MSVP), Bohunice Radioactive Waste Processing Centre (VK808 - BSC), The Main Production Unit (VK 46A - HVB) and Bitumenation Lines (VK 46B - BL) are presented. The alpha radioactive effluents into atmosphere within January 2016 (for NPP V1, MSVP, BSC, HVB and BL, respectively) were: 0.051 MBq (0.0001 of AL) for V1, 0.006 MBq (0.002% of AL) for MSVP, 0.007 MBq (0.005% of AL) for BSC, 0.027 MBq (0.004% of AL) for HVB and 0.003 MBq (0.002% of AL) for BL of aero-soles. The radioactive effluents into atmosphere and hydrosphere within a January 2016 for NPP V1, MSVP, and VK 808 BSC, respectively, were: 0.051 MBq (V1), 0.006 MBq (VK MSVP), 0.007 MBq (VK 808 BSC), 0.027 MBq (VK 46A) and 0.003 MBq (VK 46B) of aero-soles into atmosphere; 0.192 MBq (V1 and MSVP) and 0.346 MBq (TSU RAO and NPP A1) of corrosive and fission products, and 0.001 GBq (V1 and MSVP) and 10.991 GBq (TSU RAO and NPP A1) of tritium into the Vah River and 0.000 GBq (V1 and MSVP) and 0.000 MBq (TSU RAO and NPP A1) of corrosive and fission products and 0.000 GBq of tritium (V1) and 0.000 GBq of tritium (TSU RAO and NPP A1) into the Dudvah River). For the period January - January 2016 these radioactive effluents into recipient of Vah River represent for corrosive and fission products 0.192 MBq (0.0015% of AL for V1 and MSVP) and 0.346 MBq (0.003% of AL for TSU RAO and MSVP); and for tritium it is 0.001 GBq (0.00003% of AL) for V1 and MSVP, and 10.991 GBq (0.110% of AL) for TSU RAO and NPP A1 (into the Vah River) and for corrosive and fission products 0.000 MBq (V1 and MSVP) and 0.000 MBq (TSU RAO and NPP A1) (0.0000 of AL) of tritium (into the Dudvah River). Chemical effluents are reported, too.

  7. Eco information 4 Influence of operation of the plants Jadrova vyradovacia spolocnost, a.s., on the environment, locality of Bohunice, within April 2016

    International Nuclear Information System (INIS)

    2016-05-01

    In this leaflet the results of monitoring of chemical gaseous and liquid effluents into the rivers Vah and Dudvah as well as of radiation monitoring of Bohunice V1 NPP, Interim Spent Fuel Storage (MSVP), Bohunice Radioactive Waste Processing Centre (VK808 - BSC), The Main Production Unit (VK 46A - HVB) and Bitumenation Lines (VK 46B - BL) are presented. The alpha radioactive effluents into atmosphere within January - April 2016 (for NPP V1, MSVP, BSC, HVB and BL, respectively) were: 0.141 MBq (0.0002 of AL) for V1, 0.027 MBq (0.006% of AL) for MSVP, 0.029 MBq (0.016% of AL) for BSC, 0.127 MBq (0.015% of AL) for HVB and 0.009 MBq (0.006% of AL) for BL of aero-soles. The radioactive effluents into atmosphere and hydrosphere within a April 2016 for NPP V1, MSVP, and VK 808 BSC, respectively, were: 0.017 MBq (V1), 0.008 MBq (VK MSVP), 0.006 MBq (VK 808 BSC), 0.029 MBq (VK 46A) and 0.003 MBq (VK 46B) of aero-soles into atmosphere; 0.880 MBq (V1 and MSVP) and 0.397 MBq (TSU RAO and NPP A1) of corrosive and fission products, and 0.315 GBq (V1 and MSVP) and 7.163 GBq (TSU RAO and NPP A1) of tritium into the Vah River and 0.000 GBq (V1 and MSVP) and 0.000 MBq (TSU RAO and NPP A1) of corrosive and fission products and 0.000 GBq of tritium (V1) and 0.000 GBq of tritium (TSU RAO and NPP A1) into the Dudvah River). For the period January - April 2016 these radioactive effluents into recipient of Vah River represent for corrosive and fission products 2.658 MBq (0.0204% of AL for V1 and MSVP) and 1.744 MBq (0.015% of AL for TSU RAO and MSVP); and for tritium it is 0.736 GBq (0.03679% of AL) for V1 and MSVP, and 31.833 GBq (0.318% of AL) for TSU RAO and NPP A1 (into the Vah River) and for corrosive and fission products 0.000 MBq (V1 and MSVP) and 0.000 MBq (TSU RAO and NPP A1) (0.0000 of AL) of tritium (into the Dudvah River). Chemical effluents are reported, too.

  8. Eco information 2. Influence of operation of the plants Jadrova vyradovacia spolocnost, a.s., on the environment, locality of Bohunice, within February 2016

    International Nuclear Information System (INIS)

    2016-03-01

    In this leaflet the results of monitoring of chemical gaseous and liquid effluents into the rivers Vah and Dudvah as well as of radiation monitoring of Bohunice V1 NPP, Interim Spent Fuel Storage (MSVP), Bohunice Radioactive Waste Processing Centre (VK808 - BSC), The Main Production Unit (VK 46A - HVB) and Bitumenation Lines (VK 46B - BL) are presented. The alpha radioactive effluents into atmosphere within January - February 2016 (for NPP V1, MSVP, BSC, HVB and BL, respectively) were: 0.100 MBq (0.001 of AL) for V1, 0.013 MBq (0.004% of AL) for MSVP, 0.017 MBq (0.012% of AL) for BSC, 0.048 MBq (0.007% of AL) for HVB and 0.005 MBq (0.003% of AL) for BL of aero-soles. The radioactive effluents into atmosphere and hydrosphere within a February 2016 for NPP V1, MSVP, and VK 808 BSC, respectively, were: 0.049 MBq (V1), 0.007 MBq (VK MSVP), 0.011 MBq (VK 808 BSC), 0.020 MBq (VK 46A) and 0.002 MBq (VK 46B) of aero-soles into atmosphere; 0.706 MBq (V1 and MSVP) and 0.738 MBq (TSU RAO and NPP A1) of corrosive and fission products, and 0.419 GBq (V1 and MSVP) and 7.479 GBq (TSU RAO and NPP A1) of tritium into the Vah River and 0.000 GBq (V1 and MSVP) and 0.000 MBq (TSU RAO and NPP A1) of corrosive and fission products and 0.000 GBq of tritium (V1) and 0.000 GBq of tritium (TSU RAO and NPP A1) into the Dudvah River). For the period January - February 2016 these radioactive effluents into recipient of Vah River represent for corrosive and fission products 0.898 MBq (0.0069% of AL for V1 and MSVP) and 1.084 MBq (0.009% of AL for TSU RAO and MSVP); and for tritium it is 0.420 GBq (0.02098% of AL) for V1 and MSVP, and 18.470 GBq (0.185% of AL) for TSU RAO and NPP A1 (into the Vah River) and for corrosive and fission products 0.000 MBq (V1 and MSVP) and 0.000 MBq (TSU RAO and NPP A1) (0.0000 of AL) of tritium (into the Dudvah River). Chemical effluents are reported, too.

  9. Monitoring of activity of the persons and vehicles at the exit from the NPP Bohunice

    International Nuclear Information System (INIS)

    Dobis, L.; Kaizer, J.; Svitek, J.

    1998-01-01

    In this paper the technical description of the monitoring of activity of the persons and vehicles at the exit from the NPP Bohunice as well as the results of monitoring during last six months are described

  10. Information letter 10. Information about operation of Jadrova vyradovacia spolocnost, a.s. and plants SE-NPP Bohunice during October 2006

    International Nuclear Information System (INIS)

    2006-11-01

    In this leaflet results of exploitation of four units of the Bohunice V1 and V2 NPPs are presented. The electricity and heat production in October 2006 are reviewed. Within a October 2006 the electricity was produced in NPP V1: 313.778 GWh (block 1), 209.838 GWh (block 2), totally 523.616 GWh, and 5125.651 GWh within a January - October 2006. Within a October 2006 the NPP V2: blocks 3 and 4 has worked on nominal power. Processing and storage of radioactive wastes in Jadrova vyradovacia spolocnost (JAVYS) is presented. Seventeen pieces of fibre-concrete containers were processed into fibre-concrete containers in Bohunice processing centre of radioactive wastes (BSC RAO) in October 2006. Thirty-eight fibre-concrete containers were stored into Republic storage of radioactive wastes (RU RAO). Total number in RU RAO reached 1234 pieces of fibre-concrete containers, which represent 17.14 percent of storage capacity (7200 containers)

  11. Information letter 12. Information about operation of Jadrova vyradovacia spolocnost, a.s. and plants SE-NPP Bohunice during December 2006

    International Nuclear Information System (INIS)

    2007-01-01

    In this leaflet results of exploitation of four units of the Bohunice V1 and V2 NPPs are presented. The electricity and heat production in December 2006 are reviewed. Within a December 2006 the electricity was produced in NPP V1: 301.221 GWh (block 1), 281.125 GWh (block 2), totally 582.346 GWh, and 6179.205 GWh within a January - December 2006. Within a November 2006 the NPP V2: the block 3 and block 4 has worked in stabile regime according to needs of regulation. Processing and storage of radioactive wastes in Jadrova vyradovacia spolocnost (JAVYS) is presented. Twenty pieces of fibre-concrete containers were processed into fibre-concrete containers in Bohunice processing centre of radioactive wastes (BSC RAO) in December 2006. Eight fibre-concrete containers were stored into Republic storage of radioactive wastes (RU RAO). Total number in RU RAO reached 1260 pieces of fibre-concrete containers, which represent 17.50 per cent of storage capacity (7200 containers)

  12. Results of physics start-up tests of Mochovce and Bohunice units with 2-nd generation Gd fuel (average enrichment 4.87 %)

    International Nuclear Information System (INIS)

    Polakovic, F.

    2015-01-01

    There are presented main features of the fuel and the list of experimental neutron-physical characteristics measured during physics start-up tests.All together there were carried out 14 physics start-ups at Bohunice and Mochovce Units with the new type of fuel. Differences between theoretical and experimental neutron-physical characteristics were statistically processed and compared with the tests acceptance criteria. There are summarized results of reactor physics start-ups with 2-nd generation Gd fuel usage [ru

  13. KS-150 reactor control

    International Nuclear Information System (INIS)

    Wagner, K.

    1974-01-01

    A thorough description is presented of the control and protection system of the Bohunice A-1 reactor. The system including auxiliary facilities was developed, manufactured and installed at the reactor by the SKODA Works, Plzen. The system parameters are listed and a brief account is also given of the development efforts and of the physical and power start-up of the A-1 nuclear power plant. (L.O.)

  14. Intercomparison of liquid metal fast reactor seismic analysis codes. V.1: Validation of seismic analysis codes using reactor core experiments. Proceedings of a research co-ordination meeting held in Vienna, 16-17 November 1993

    International Nuclear Information System (INIS)

    1995-05-01

    The Research Co-ordination Meeting held in Vienna, 16-17 November 1993, was attended by participants from France, India, Italy, Japan and the Russian Federation. The meeting was held to discuss and compare the results obtained by various organizations for the analysis of Italian tests on PEC mock-up. The background paper by A. Martelli, et al., Italy, entitled Fluid-Structure Interaction Experiments of PEC Core Mock-ups and Numerical Analysis Performed by ENEA presented details on the Italian PEC (Prova Elementi di Combustibile, i.e. Fuel Element Test Facility) test data for the benchmark. Several papers were presented on the analytical investigations of the PEC reactor core experiments. The paper by M. Morishita, Japan, entitled Seismic Response Analysis of PEC Reactor Core Mock-up, gives a brief review of the Japanese data on the Monju mock-up core experiment which had been distributed to the participating countries through the IAEA. Refs, figs and tabs

  15. Lessons from feedback of safety operating experience for reactor physics

    International Nuclear Information System (INIS)

    Suchomel, J.; Rapavy, S.

    1999-01-01

    Analyses of events in WWER operations as a part of safety experience feedback provide a valuable source of lessons for reactor physics. Examples of events from Bohunice operation will be shown such as events with inadequate approach to criticality, positive reactivity insertions, expulsion of a control rod from shut-down reactor, problems with reactor protection system and control rods. (Authors)

  16. Irradiation temperature measurement of the reactor pressure vessel surveillance specimen in the programmes of radiation degradation monitoring

    International Nuclear Information System (INIS)

    Kupca, L.; Stanc, S.; Simor, S.

    2001-01-01

    The information's about the special system of irradiation temperature measurement, used for reactor pressure vessel surveillance specimen, which are placed in reactor thermal shielding canals are presented in the paper. The system was designed and realized in the frame of Extended Surveillance Specimen Programme for NPP V-2 Jaslovske Bohunice and Modern Surveillance Specimen Programme for NPP Mochovce. Base design aspects, technical parameters of realization and results of measurement on the two units in Bohunice and Mochovce NPPs are presented too. (Authors)

  17. V-1 nuclear power plant standby RPP-16S computer software

    International Nuclear Information System (INIS)

    Suchy, R.

    1988-01-01

    The software structure of the function of program modules of the RPP-16S standby computer which is part of the information system of the V-1 Bohunice nuclear power plant are described. The multitasking AMOS operational system is used for the organization of programs in the computer. The program modules are classified in five groups by function, i.e., in modules for the periodical collection of values and for the measurement of process quantities for both nuclear power plant units; for the primary processing of the values; for the monitoring of exceedance of preset limits; for unit operators' communication with the computer. The fifth group consists of users program modules. The standby computer software was tested in the actual operating conditions of the V-1 power plant. The results showed it operated correctly; minor shortcomings were removed. (Z.M.). 1 fig

  18. Chemistry monitoring and diagnostic system at NPP Jaslovske Bohunice

    International Nuclear Information System (INIS)

    Smiesko, Ivan; Figedy, Stefan

    2012-09-01

    This paper provides a description of water chemistry monitoring and diagnostic system installed at Slovak NPP Jaslovske Bohunice. System has complex architecture and covers laboratory data, chemistry and radiochemistry on-line monitoring data, process data acquisition and processing and diagnostics. Pre-filtered data from process computer and chemistry on-line monitors are recorded together with laboratory data in the ORACLE-based information system CHEMIS with many presentation and processing features. Brief information is given about the basic features of a newly developed diagnostic system for early detection and identification of anomalies incoming in the water chemistry regime of the primary and secondary circuit of VVER-440 type unit. This system, called SACHER (System of Analysis of Chemical Regime) has been installed within the major modernization project at the NPP Bohunice in the Slovak Republic. System SACHER has been developed fully in MATLAB environment. Diagnostic system works exclusively with available on-line data as an operation personnel support application allowing effective response to adverse chemistry events/trends. The availability of prompt information about the chemical conditions of the primary and secondary circuit is very important in order to prevent the undue corrosion and deposit build-up processes within the plant systems. The typical chemical information systems that exist and work at the NPPs give the user values of the measured quantities together with their time trends and other derived values. It is then the experienced user's role to recognize the situation the monitored process is in and make the subsequent decisions and take the measures. The SACHER system, based on the computational intelligence techniques, inserts the elements of intelligence into the overall chemical information system. It has the modular structure with the following most important modules: - normality module- its aim is to recognize that the process

  19. Monitoring of Persons at the Exit from Bohunice NPP

    International Nuclear Information System (INIS)

    Kaizer, J.; Svitek, J.

    2001-01-01

    Full text: IAEA defines the principal requirement 'defence in depth' as a multilayer system in its authorised document - International Basic Safety Standards for Protection against Ionising Radiation, Safety Series No. 115. The principle of the multilayer system is: a failure at one zone is compensated or corrected at subsequent zones. The main argument why Bohunice NPP modernised its monitoring system at the exit from NPP was the implementation of the principle 'defence in depth'. Several instruments PM7 (Eberline) equipped with the plastic scintillation detectors had been bought because of the modernisation. The instruments had to be integrated into overall security system NPP without any restriction to the number of passing people. The supplier had to modify the basic instrument operation. NPP required a 'dynamic' monitoring version, this means the operation without stopping of a person within the instrument. After the modification the value of the RDA (Reliable Detectable Activity) of the instruments PM7 was within the interval 9.25-10.4 kBq for 137 Cs (dotted source in the middle of the instrument). RDA for the mix of activation products was 2-3 times lower. In conclusion of our paper the results of the monitoring are presented within tree years as well as a discussion about these results. Maximum values of contaminations measured were very low (several kBq) that represented very low risk from potential exposure. (author)

  20. Information letter 6. Information about operation of GovCo, a.s. and plant SE-NPP Bohunice during June 2006

    International Nuclear Information System (INIS)

    2006-07-01

    In this leaflet results of exploitation of four units of the Bohunice V-1 and V-2 NPPs are presented. The electricity and heat production in June 2006 are reviewed. Within a June 2006 the electricity was produced in GovCo, a.s.: 289.150 GWh (block 1), 262.103 GWh (block 2), totally 551.253 GWh, and 321.515 GWh within a January - June 2006 and in SE-EBO, NPP V2: 278.896 GWh (block 3), 0 GWh (block 4), totally 278.896 GWh, and 2778.249 GWh within a January - June 2006. The heat production in June 2006 was 38 212 GJ, and within a January - June 2006 it was produced 1 098 605 GJ of heat. Processing and storage of radioactive wastes in GovCo, a.s. - Decommissioning of Nuclear Installations and Spent Fuel and Rad-waste Management (VYZ) is presented. Thirty-two pieces of fibre-concrete containers were processed into fibre-concrete containers in Bohunice processing centre of radioactive wastes (BSC RAO) in January 2006. Sixteen fibre-concrete containers were stored into Republic storage of radioactive wastes (RU RAO). Total number in RU RAO reached 1132 pieces of fibre-concrete containers, which represent 15.72 per cent of storage capacity (7200 containers). The technique of SE-VYZ in decommissioning of A1 NPP is described

  1. The common project for completion of Bubbler Condenser Qualification (Bohunice, Mochovce, Dukovany and Paks NPPs)

    International Nuclear Information System (INIS)

    Jaroslav, H.; Pavol, B.

    2003-01-01

    Described is the common project for completion of bubbler condenser qualification for nuclear power plants in Bohunice, Mochovice, Dukovany and Paks. Functionality of the bubbler condenser was elaborated during the simulation of the main steam line brake, medium break and small break LOCA. On this basis the appropriate operation of bubbler condenser containment under accident conditions can be positively confirmed

  2. Radiological characterisation on V1 NPP technological systems and buildings - Contamination

    International Nuclear Information System (INIS)

    Hanzel, Richard; Rapant, Tibor; Svitek, Jaroslav

    2012-01-01

    Since 2001, the preparation of V1 NPP practical decommissioning has been supported and partly financed by the Bohunice International Decommissioning Support Fund, under the administration of the European bank for Reconstruction and development. AMEC Nuclear Slovakia, together with partners STM Power and EWN GmbH, performed BIDSF B.4 project - Decommissioning database development. The main purpose of the B6.4 project was to develop a comprehensive physical and radiological inventory database to support RAW management development of the decommissioning studies and decommissioning project of Bohunice V1 NPP. AMEC Nuclear Slovakia was responsible mainly for DDB design, planning documents and physical and radiological characterization including sampling and analyses of the plant controlled area. The objective of V1 NPP radiological characterization was summarisation of sampling and analyses results, description of methodology used for radiological characterization and determination of the V1 NPP radiological inventory. Results of the characterization survey included the identification and distribution of contamination in buildings, structures, and other site facilities or other impacted media. The characterization survey clearly identified those portions of the site that have been affected by site activities and are contaminated. The survey also identified the portions of the site that have not been affected by these activities and can be marked as 'not impacted'. Radiological data have been presented also on the basis of index RAI level, where 5 radiological classes have been defined. On the basis of sampling and analyses results following radiological parameters have been assigned to all impacted components and civil structures included in DDB: dose rate in contact, dose rate in distance 1 m, external surface contamination, internal surface contamination and volume/mass contamination. Each room in controlled area has been described by following radiological parameters

  3. Computer modelling the potential benefits of amines in NPP Bohunice secondary circuit

    International Nuclear Information System (INIS)

    Fountain, M.J.; Smiesko, I.

    1998-01-01

    The use of computer modelling of PWR and WWER secondary circuit chemistry was already demonstrated in the past. The model was used to illustrate the technical and economic advantages, compared with ammonia, of using an 'advanced', high basicity, low volatility amines to raise the liquid phase pH(T) in the moisture separator and other areas swept by wet steam. Since the 1995, this technique has been successfully applied to a number of power plants and the computer model has been progressively developed. This paper describes the preliminary results of an ongoing assessment being carried out for the VVER 440 plants at Bohunice. The work for Bohunice is being funded by the 'Know How Fund', a department in the British Government's Foreign and Commonwealth Office. (J.P.N.)

  4. Programmes design for Bohunice NPP personnel other than control room operators

    International Nuclear Information System (INIS)

    Kalincik, L.

    2002-01-01

    This paper deals with project development of training programmes for non-licenced NPP personnel-masters, field operators, maintenance and technical supporting personnel. The programme development focuses on the part stage and on the job training at NPP. Bohunice NPP belongs to plants with higher specific number of personnel per installed power capacity. This factor also influenced the choice of programmes design. Undermentioned procedure is one of various approaches to SAT exploitation for training programmes design. (author)

  5. ITER concept definition. V.1

    International Nuclear Information System (INIS)

    1989-01-01

    Under the auspices of the International Atomic Energy Agency (IAEA), an agreement among the four parties representing the world's major fusion programs resulted in a program for conceptual design of the next logical step in the fusion program, the International Thermonuclear Experimental Reactor (ITER). The definition phase, which ended in November, 1989, is summarized in two reports: a brief summary is contained in the ITER Definition Phase Report (IAEA/ITER/DS/2); the extended technical summary and technical details of ITER are contained in this two-volume report. The first volume of this report contains the Introduction and Summary, and the remainder will appear in Volume II. In the Conceptual Design Activities phase, ITER has been defined as being a tokamak device. The basic performance parameters of ITER are given in Volume I of this report. In addition, the rationale for selection of this concept, the performance flexibility, technical issues, operations, safety, reliability, cost, and research and development needed to proceed with the design are discussed. Figs and tabs

  6. Nuclear safety in Slovak Republic. Safety analysis reports for WWER 440 reactors

    International Nuclear Information System (INIS)

    Rohar, S.

    1999-01-01

    Implementation of nuclear power program is connected to establishment of regulatory body for safe regulation of siting, construction, operation and decommissioning of nuclear installations. Licensing being one of the most important regulatory surveillance activity is based on independent regulatory review and assessment of information on nuclear safety for particular nuclear facility. Documents required to be submitted to the regulatory body by the licensee in Slovakia for the review and assessment usually named Safety Analysis Report (SAR) are presented in detail in this paper. Current status of Safety Analysis Reports for Bohunice V-1, Bohunice V-2 and Mochovce NPP is shown

  7. Current status of LTO licensing programme for Bohunice nuclear power plant

    International Nuclear Information System (INIS)

    Borak, J.; Kupca, L.

    2012-01-01

    The objective of long term operation (LTO) licensing programme for Bohunice nuclear power plant is to demonstrate that the relevant structures and components shall perform their functions throughout the entire LTO period during which they shall meet all the relevant safety requirements. All the activities-which should result in utility's request to obtain the licence for LTO-must be performed in line with the relevant legal basis. As of May 2012, the anticipated duration of currently running programme is thirteen months. All relevant documentation, required by the established legal basis, shall be submitted to the licensing authority one year before the Unit 3 design life expiry. (author)

  8. Environment monitoring and residents health condition monitoring of nuclear power plant Bohunice region

    International Nuclear Information System (INIS)

    Letkovicova, M.; Rehak, R.; Stehlikova, B.; Celko, M.; Hraska, S.; Klocok, L.; Kostial, J.; Prikazsky, V.; Vidovic, J.; Zirko, M.; Beno, T.; Mitosinka, J.

    1998-01-01

    The report contents final environment evaluation and selected characteristic of residents health physics of nuclear power plant Bohunice region. Evaluated data were elaborated during analytical period 1993-1997.Task solving which results are documented in this final report was going on between 1996- 1998. The report deals in individual stages with the following: Information obtaining and completing which characterize demographic situation of the area for the 1993-1997 period; Datum obtaining and completing which contain selected health physics characteristics of the area residents; Database structures for individual data archiving from monitoring and collection; Brief description of geographic information system for graphic presentation of evaluation results based on topographic base; Digital mapping structure description; Results and evaluation of radionuclide monitoring in environment performed by Environmental radiation measurements laboratory by the nuclear power plant Bohunice for the 1993-1997 period. Demographic situation evaluation and selected health physics characteristics of the area of nuclear power plant residents for the 1993-1997 period are summarized in the final part of the document. Monitoring results and their evaluation is processed in graph, table, text description and map output forms. Map outputs are processed in the geographic information system Arc View GIS 3.0a environment

  9. Welding electrode for peripheral welds of A-1 reactor pressure vessel

    International Nuclear Information System (INIS)

    Lakatos, L.

    1975-01-01

    The properties are outlined of the VUZ-AC1-52 welding electrode used in welding the Bohunice A-1 reactor pressure vessel. The mechanical properties of welded joints after the final thermal treatment are summed up. (J.K.)

  10. Comparison of Planning, Management and Organizational Aspects of Nuclear Power Plants A1 and V1 Decommissioning

    Energy Technology Data Exchange (ETDEWEB)

    Stubna, M.; Michal, V., E-mail: Marian.Stubna@vuje.sk, E-mail: V.Michal@iaea.org [VUJE, Inc. Trnava (Slovakia); Daniska, V., E-mail: Daniska@decom.sk [DECOM, Inc. Trnava (Slovakia); Sirota, J., E-mail: Sirota.Jan@javys.sk [JAVYS, Inc. Bratislava, (Slovakia)

    2013-08-15

    This contribution deals with planning, management and organizational aspects of decommissioning of NPP shut down due to the accident (prototype NPP A1) and NPP shut down after normal operation (NPP V1). The A1 and V1 NPPs are located very close in Bohunice nuclear site however both plants have very different technology and operational history. The preparation of A1 NPP decommissioning strategy and relevant decommissioning plans was long term process, because the plant was shut down after the accident in 1977 and decommissioning was implemented first time in Slovakia with many specific difficulties. The decommissioning planning of V1 NPP was shorter and easier, because the plant was shut down after normal operation, there were lessons learned from the A1 NPP decommissioning planning, available legislation, available financing etc. Development of decommissioning strategies, preparation and planning for decommissioning, development of legislation for decommissioning, management of decommissioning projects and other aspects are described and compared. Lessons learned are formulated on the basis of analysis of past, ongoing and planned decommissioning activities in Slovakia. (author)

  11. GRIP HURRICANE IMAGING RADIOMETER (HIRAD) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GRIP Hurricane Imaging Radiometer (HIRAD) V1 dataset contains measurements of brightness temperature taken at 4, 5, 6 and 6.6 GHz, as well as MERRA 2 m wind...

  12. USEEIO v1.1 - Matrices

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset provides the basic building blocks for the USEEIO v1.1 model and life cycle results per $1 (2013 USD) demand for all goods and services in the model in...

  13. National Report

    International Nuclear Information System (INIS)

    Lipar, M.

    2001-01-01

    Power production in Slovak Republic is presented. The safety at the NPPs Bohunice V-1, V-2 and Mochovce is discussed. The events - Automatic Reactor Scram at Bohunice 1 and Power Reduction - Home Load at Bohunice 2 due to short circuit in the external grid on 22 May 2001 and Manual Reactor Scram at Mochovce 2 NPP due to Loss of Offsite Power on 30 May 2001 are described

  14. Planning for environmental restoration of the contaminated banks near NPP Bohunice

    International Nuclear Information System (INIS)

    Slavik, O.; Moravek, J.; Vladar, M.

    1995-01-01

    The 18 km long banks of the Bohunice NPP waste water recipient are contaminated by cesium-137 as a result of two accidents on the CO 2 cooled NPP A 1 unit in 1976 and 1977. Since 1992, all he contaminated waste waters dumping from NPP Bohunice has been carried out directly to the Vah River through a specially constructed 15 km long pipeline. The final extent of contamination in the Bohunice site is represented. The overall contaminated area in this site with cesium-137 activity above 1 Bq/g of soil is about 67000 m 2 and thus, the corresponding volume of top 20 cm thick soil layer is about 13000 m 3 . For optimizing less costly remedial measures (warning signs...) an agreed scenario with a pre-estimated factor factor collective dose 2.10 -7 man.Sv.y -1 /(m 2 .Bq 137 Cs.g -1 ) was applied. Limitation of individual effective doses according to a site specific stay scenario was also considered for this purposes with a limiting value of 0.25 mSv/y. Cost analysis of available remedial techniques were carried out, too. Two techniques have been selected for the contaminated banks restoration project: 1) removing/disposal of 20 cm soil top layer from steep and unengineered banks, and 2) mechanical dilution/fixation of contamination by clean 15 cm soil cover for the contaminated flat areas. Two-fold reduction of anticipated potential radiation risk were accepted, maximally, for the lastly mentioned technique, however cost saving is considerable (about 10-time lower the cost comparing to removing/disposal technique one). The basic acceptance limits AL for 137 Cs in soil and criteria size of continuously contaminated bank areas were derived as: AL 200 = 6.0 Bq/g and 800 m 2 (300 m) or AL 50 8.0 Bq/g and 200 m 2 (80 m) for removing/disposal of the soil on steep unengineered banks. For clean soil covering technique the resulting limits are in an interval AL 50C = 8 up to 16 Bq/g. According to the criteria developed, it is necessary to subject to restoration about 11000 m 2 of

  15. Planning for environmental restoration of the contaminated banks near NPP Bohunice

    Energy Technology Data Exchange (ETDEWEB)

    Slavik, O; Moravek, J [Nuclear Power Plants Research Institute, a.s., Trnava (Slovakia); Vladar, M [Inst. of Preventive and Clinical Medicine, Bratislava (Slovakia)

    1996-12-31

    The 18 km long banks of the Bohunice NPP waste water recipient are contaminated by cesium-137 as a result of two accidents on the CO{sub 2} cooled NPP A{sub 1} unit in 1976 and 1977. Since 1992, all he contaminated waste waters dumping from NPP Bohunice has been carried out directly to the Vah River through a specially constructed 15 km long pipeline. The final extent of contamination in the Bohunice site is represented. The overall contaminated area in this site with cesium-137 activity above 1 Bq/g of soil is about 67000 m{sup 2} and thus, the corresponding volume of top 20 cm thick soil layer is about 13000 m{sup 3}. For optimizing less costly remedial measures (warning signs...) an agreed scenario with a pre-estimated factor factor collective dose 2.10{sup -7} man.Sv.y{sup -1}/(m{sup 2}.Bq{sup 137}Cs.g{sup -1}) was applied. Limitation of individual effective doses according to a site specific stay scenario was also considered for this purposes with a limiting value of 0.25 mSv/y. Cost analysis of available remedial techniques were carried out, too. Two techniques have been selected for the contaminated banks restoration project: 1) removing/disposal of 20 cm soil top layer from steep and unengineered banks, and 2) mechanical dilution/fixation of contamination by clean 15 cm soil cover for the contaminated flat areas. Two-fold reduction of anticipated potential radiation risk were accepted, maximally, for the lastly mentioned technique, however cost saving is considerable (about 10-time lower the cost comparing to removing/disposal technique one). The basic acceptance limits AL for {sup 137}Cs in soil and criteria size of continuously contaminated bank areas were derived as: AL{sub 200} = 6.0 Bq/g and 800 m{sup 2} (300 m) or AL{sub 50} 8.0 Bq/g and 200 m{sup 2} (80 m) for removing/disposal of the soil on steep unengineered banks. For clean soil covering technique the resulting limits are in an interval AL{sub 50C} = 8 up to 16 Bq/g. (Abstract Truncated)

  16. Principles and criteria for environmental restoration of the contaminated banks near NPP Bohunice

    International Nuclear Information System (INIS)

    Slavik, O.; Moravek, J.

    1995-01-01

    The 18 km long banks of the Bohunice NPP waste water recipient are contaminated by 137 Cs as a result of two accidents on the CO 2 cooled NPP-A1 unit in 1976 and 1977. Contamination acceptance limits 6 or 8 Bq 137 Cslg of soil, depending on contaminated area size, were derived on the basis of developed principles, and approved by the authorities. Removing and safe burial of 1,100 m 3 of contaminated soil from steep area and 15 cm thick clean soil covering on about 1ha of flat area of the contaminated banks is planned in frame of the re-considered restoration project implementation in 1995/96. (author)

  17. IAEA Operational Safety Team Review Bohunice Nuclear Power Plant, Slovak Republic

    International Nuclear Information System (INIS)

    2010-01-01

    Full text: An international team of nuclear installation safety experts, led by the International Atomic Energy Agency (IAEA), has reviewed Slovakia's Bohunice Nuclear Power Plant (BNPP) for its safety practices and has noted a series of good practices as well as recommendations to reinforce them. The IAEA assembled an international team of experts at the request of the Government of Slovak Republic to conduct an Operational Safety Review (OSART) of Bohunice NPP. Under the leadership of the IAEA's Division of Nuclear Installation Safety, the OSART team performed an in-depth operational safety review from 1 to 18 November 2010. The team was made up of experts from Belgium, Canada, China, the Czech Republic, France, Sweden, the United Kingdom and the IAEA. An OSART mission is designed as a review of programmes and activities essential to operational safety. It is not a regulatory inspection, nor is it a design review or a substitute for an exhaustive assessment of the plant's overall safety status. The team at BNPP conducted an in-depth review of the aspects essential to the safe operation of the NPP, which largely is under the control of the site management. The conclusions of the review are based on the IAEA's Safety Standards and proven good international practices. The review covered the areas of Management, Organization and Administration; Operations; Maintenance; Technical Support; Operating Experience; Radiation Protection; Chemistry and Emergency Planning and Preparedness. Long Term Operation assessment has been requested by the plant in addition to the standard OSART program. The OSART team has identified good plant practices which will be shared with the rest of the nuclear industry for consideration of their application. Examples include: BNPP has implemented a comprehensive set of technical and organizational measures which have significantly reduced the production of liquid radioactive waste; BNPP has developed an automatic transfer of dosimetry data

  18. 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.)

  19. 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.)

  20. Radiation protection in decommissioning of the NPP V1

    International Nuclear Information System (INIS)

    Svitek, J.; Kaizer, J.; Siska, J.

    2014-01-01

    What's new in decommissioning of the NPP V1? In 2014 the first stage of the decommissioning should be finished. The program of the first stage was characterized by decommissioning of the non-contaminated facilities and buildings (facilities and buildings out of the control area). However, during the first stage, two key activities were done during which radiation protection had to be especially supervised: BIDSF project - Treatment and Conditioning of Wet Historical Waste - Sludge and Sorbents in the operational tanks NPP V1 (the treatment has been the condition of the regulatory body for the ending of the first stage) and preparation of decontamination of both primary circuits NPP (without reactors). In the year 2015, the second stage of decommissioning should be started. Program for the second stage is broad and it includes fragmentation and treatment of activated parts of the primary circuits (reactors, their internal parts, shielding cassettes). Modification of the radiation protection equipment on the NPP site has been made by BIDSF projects. During the first stage, two basic projects have been done: C12 - Refurbishment of the radiation protection monitoring equipment and C-10 - Free release of decommissioning materials. The present state of monitoring systems, as the result of the aforementioned projects, and the first experiences are main part of this presentation. Another activity, which prepared basic conditions for an execution of radiation protection in the second stage of decommissioning, was the preparation of documents for the procurement of license for the second stage of decommissioning. (authors)

  1. Assessment of ICARE/CATHARE V1 Severe Accident Code

    International Nuclear Information System (INIS)

    Chatelard, Patrick; Fleurot, Joelle; Marchand, Olivier; Drai, Patrick

    2006-01-01

    The ICARE/CATHARE code system has been developed by the French 'Institut de Radioprotection et de Surete Nucleaire' (IRSN) in the last decade for the detailed evaluation of Severe Accident (SA) consequences in a primary system. It is composed of the coupling of the core degradation IRSN code ICARE2 and of the thermal-hydraulics French code CATHARE2. It has been extensively used to support the level 2 Probabilistic Safety Assessment (PSA-2) of the 900 MWe PWR. This paper presents the synthesis of the ICARE/CATHARE V1 assessment which was conducted in the frame of the 'International ICARE/CATHARE Users' Club', under the management of IRSN. The ICARE/CATHARE V1 validation matrix is composed of more than 60 experiments, distributed in few thermal-hydraulics non-regression tests (to handle the front end phase of a severe accident), numerous Separate-Effect Tests, about 30 Integral Tests covering both the early and the late degradation phases, as well as a 'circuit' experiment including hydraulics loops. Finally, the simulation of the TMI-2 accident was also added to assess the code against real conditions. This validation task was aimed at assessing the ICARE/CATHARE V1 capabilities (including the stand-alone ICARE2 V3mod1 version) and also at proposing recommendations for an optimal use of this version ('Users' Guidelines'). Thus, with a correct account for the recommended guidelines, it appeared that the last ICARE/CATHARE V1 version could be reasonably used to perform best-estimate reactor studies up to a large corium slumping into the lower head. (authors)

  2. Evaluation of an external exposure of a worker during manipulation with waste packages stored in Bohunice radioactive waste treatment centre

    International Nuclear Information System (INIS)

    Slimak, A.; Hrncir, T.; Necas, V.

    2012-01-01

    The paper briefly describes current state of radioactive waste management as well as radioactive waste treatment and conditioning technologies used in Bohunice Radioactive Waste Treatment Centre. Radioactive Waste management includes pretreatment, treatment, conditioning, storage, transport and disposal of radioactive waste. Presented paper deals with the evaluation of an external exposure of a worker during manipulation with fibre-reinforced concrete container stored under shelter object. The external exposure of a worker was evaluated using VISIPLAN 3D ALARA code. (Authors)

  3. Analysis of the mortality development of the population in the surroundings of Bohunice NPP using Fuzzy logic methods

    International Nuclear Information System (INIS)

    Letkovicova, M.; Durov, M.; Stehlikova, B.

    2001-01-01

    We pursue the vicinity of Bohunice NPP. The vicinity has cyclic form with radius of 30 km, what represents an area approximately 2 800 km 2 . This area of pursued vicinity is requisite by the security report of Bohunice NPP. To the presumptive calculations we used the complete databases of Register of death, Register of municipalities and of Register of age structure of the inhabitants of the Slovak republic from 1993 to 1999, fully-fashioned in Statistical authority of the Slovak republic. We work with databases, which don't contain personal identifications. We pursue the evolution of the mortality by the indicators of the mortality, calculated by the WHO. By the literary sources and by our experience is necessary the sum at least of three years to calculation of stable demographic and epidemiological parameters. Therefore we work with the method of short time series. The basic observed unit, which is represented by one value of the indicator, is one municipality. All our assessing analyses are calculated from triennial sums of all indicators, so we work with man-years. Advanced report is the adjusted extract from Complex report on situation of environment and health of the inhabitants in vicinity of Bohunice NPP in 1999, which was advanced by our society in March 2001. (authors)

  4. V1 mechanisms underlying chromatic contrast detection

    Science.gov (United States)

    Hass, Charles A.

    2013-01-01

    To elucidate the cortical mechanisms of color vision, we recorded from individual primary visual cortex (V1) neurons in macaque monkeys performing a chromatic detection task. Roughly 30% of the neurons that we encountered were unresponsive at the monkeys' psychophysical detection threshold (PT). The other 70% were responsive at threshold but on average, were slightly less sensitive than the monkey. For these neurons, the relationship between neurometric threshold (NT) and PT was consistent across the four isoluminant color directions tested. A corollary of this result is that NTs were roughly four times lower for stimuli that modulated the long- and middle-wavelength sensitive cones out of phase. Nearly one-half of the neurons that responded to chromatic stimuli at the monkeys' detection threshold also responded to high-contrast luminance modulations, suggesting a role for neurons that are jointly tuned to color and luminance in chromatic detection. Analysis of neuronal contrast-response functions and signal-to-noise ratios yielded no evidence for a special set of “cardinal color directions,” for which V1 neurons are particularly sensitive. We conclude that at detection threshold—as shown previously with high-contrast stimuli—V1 neurons are tuned for a diverse set of color directions and do not segregate naturally into red–green and blue–yellow categories. PMID:23446689

  5. METEOR v1.0 - User's Guide

    International Nuclear Information System (INIS)

    Palomo, E.

    1994-01-01

    This script is a User's Guide for the software package METEOR for statistical analysis of meteorological data series. The original version of METEOR have been developed by Ph.D. Elena Palomo, CIEMAT-IER, GIMASE. It is built by linking programs and routines written in FORTRAN 77 and it adds the graphical capabilities of GNUPLOT. The shape of this toolbox was designed following the criteria of modularity, flexibility and agility criteria. All the input, output and analysis options are structured in three main menus: i) the first is aimed to evaluate the quality of the data set; ii) the second is aimed for pre-processing of the data; and iii) the third is aimed towards the statistical analyses and for creating the graphical outputs. Actually the information about METEOR is constituted by three documents written in spanish: 1) METEOR v1.0: User's guide; 2) METEOR v1.0: A usage example; 3) METEOR v1.0: Design and structure of the software package. (Author)

  6. 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...

  7. Analysis of the NPP-V1 primary circuit fast cooldown

    International Nuclear Information System (INIS)

    Filo, J.; Bazso, Z.; Vranka, L.

    1994-01-01

    Results of thermal-hydraulic calculations of the NPP-V1 primary circuit fast cooldown during small leakage through openings of diameter 20, 32 and 50 mm as well as analyses of cooldown following the steam pipeline break at nominal and null reactor power are given in this paper. 4 refs, 24 figs, 1 tab

  8. ICARE/CATHARE V1: Capabilities and applications

    International Nuclear Information System (INIS)

    Zabiego, M.; Guillard, V.; Fichot, F.; Marchand, O.; Chatelard, P.; Camous, F.; Barre, F.; Lefevre, B.

    2001-01-01

    The ICARE/CATHARE code is designed to calculate in a mechanistic way reactor core damage and primary circuit behaviour in PWRs. It is developed at the French Institute for Nuclear Protection and Safety (IPSN), as an analytical support of the in-pile experimental PHEBUS programs and for studies of reactor sequences in nuclear reactors. ICARE/CATHARE V1 includes the latest version of ICARE2 (V3Mod0) which features a comprehensive set of models for late degradation allowing to follow the materials from their early melting in the core region to their later relocation into the lower plenum. It also includes the thermal-hydraulics code CATHAREZ (V1.3L/b 1) which enables to take into account the whole primary circuit and its impact on the degradation. ICARE2 describes a set of components representing either the vessel structures (fuel and control rods, barrel, vessel, etc.) or the solid debris, or the melt, or the gas. The vessel volume is discretized on a two-dimensional cylindrical meshing. Each component is described by its volume fraction in the mesh, its composition and its temperature. The solid components also have a specific geometry: rods are represented as cylinders, debris particles as a set of spheres, etc.. Several applications have already been performed, either with the stand-alone version of ICARE2 or with the coupled ICARE/CATHARE version. An application of the coupled version to the calculation of the first two phases of the TMI2 accident is presented. It shows that the coupling enables both codes to extend their range of application towards the complete calculation of a severe accident sequence. Although the calculation could not be performed up to the late degradation phase, it proves the operability of the coupled version. The results are in good agreement with TMI data during the LOCA phase, and the core uncover and degradation phenomena are qualitatively well reproduced. An application of the stand-alone ICARE2 version, including all the late

  9. Is decommissioning of the NPP V-1 in the years 2006/2008 justified?

    International Nuclear Information System (INIS)

    Hudcovsky, S.; Dvorak, K.

    2001-01-01

    The article asks for very detailed safety and technical analysis, making assessments of political reasons. It would be reasonable to prepare arguments for change of present governmental decision, which is still valid. Political decision is for a politician. Main lifetime of nuclear powe plant depends on pressurized reactor vessel. One of the big problem is reactor vessel embrittlement and this article provides the information on annealing which was already done and this problem has been solved at reasonable costs. Forecast for fatigue of reactor vessel for year 2010 is just 15%. Technical condition of V-1 NPP in 2010 will be not worse compared with first years of operation. There are no technical obstacles to stop the operation of V-1 NPP. (authors)

  10. 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.)

  11. Assessment of the integrity of WWER type reactor pressure vessels

    International Nuclear Information System (INIS)

    Brumovsky, M.

    1995-01-01

    Procedures are given for the assessment of the residual lifetime of reactor pressure vessels with respect to a sudden failure, the lifetime of vessels with defects disclosed during in-service inspections, and the fatigue or corrosion-mechanical lifetime. Also outlined are the ways of assessing the effects of major degradation mechanisms, i.e. radiation embrittlement, thermal aging, and fatigue damage, including the use of calculated values and experimental examination, by means of surveillance specimens in particular. All results of assessment performed so far indicate that the life of reactor pressure vessels at the Dukovany, Jaslovske Bohunice, and Temelin nuclear power plants is well secured. 7 figs., 3 refs

  12. Network interactions: non-geniculate input to V1.

    Science.gov (United States)

    Muckli, Lars; Petro, Lucy S

    2013-04-01

    The strongest connections to V1 are fed back from neighbouring area V2 and from a network of higher cortical areas (e.g. V3, V5, LOC, IPS and A1), transmitting the results of cognitive operations such as prediction, attention and imagination. V1 is therefore at the receiving end of a complex cortical processing cascade and not only at the entrance stage of cortical processing of retinal input. One elegant strategy to investigate this information-rich feedback to V1 is to eliminate feedforward input, that is, exploit V1's retinotopic organisation to isolate subregions receiving no direct bottom-up stimulation. We highlight the diverse mechanisms of cortical feedback, ranging from gain control to predictive coding, and conclude that V1 is involved in rich internal communication processes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Borate compound content reduction in liquid radioactive waste from nuclear power plants with VVER reactor

    International Nuclear Information System (INIS)

    Szalo, A.; Zatkulak, M.

    2000-01-01

    This paper describes the current status of liquid waste (evaporator concentrates) inventory at V-1 and V-2 NPPs in Jaslovske Bohunice and the intention to separate boron from them with respect to waste minimisation and improvement of physical and chemical properties for further waste treatment and conditioning. Preliminary results of laboratory experiments concerned to borate crystallisation after pH adjustment with nitric or formic acid performed in the 1998 are given. At the present time laboratory experiments continuing - next acids, coagulation with carbon oxide, electrolytic process, ion exchange resin, study of decontamination factors, immobilization of boric acid, decrease radioactivity, purification of boron-contained compounds. Slovenske Elektrarne have accumulated 7,000 m 3 of evaporator concentrates containing 100-180 g/l borate. In order to make more storage space available, it is proposed to remove some of the borate in the liquor by precipitation as sodium tetraborate and immobilise in either cement of bitumen. The supernate can be further volume reduced by evaporation and returned to the tanks. Slovenske Elektrarne are currently evaluating acid addition to the pH 12-13 concentrate to reduce the borate solubility. However, this adds to the salt burden of the waste through this chemical addition -thus creating future increases in conditioning and disposal costs. Boric acid is used in pressurized water as a soluble neutron poison to control reactivity and also to assure a safety margin in the spent fuel pool and during refuelling operations. Boric acid is also present in the water reserved for injection into the reactor in the event of postulated accidents. (author)

  14. Increasing of leak-tightness of hermetic zone and other important components in NPPs

    International Nuclear Information System (INIS)

    Murani, J.

    2001-01-01

    The performed by VUEZ resealing works in the hermetic compartments/containment of WWER 440 and WWER 1000 NPPs in Slovakia (Jaslovske Bohunice V-1 NPP, Jaslovske Bohunice V-2 NPP, Mochovce NPP), the Czech Republic (Dukovany NPP, Temelin NPP) and Hungary (Pask NPP) are presented. The leakage rate from hermetic compartments at individual NPP reactor units are shown.The VUEZ activities in field of resealing of weld joints in pools and tanks in the Jaslovske Bohunice V-1 NPP and innovation of the seal of reactor pit protective hood (kolpak) are described. The principle of operation and practical experience of the SMU-V system implemented in the Jaslovske Bohunice V-1 NPP (WWER 440 - V 230) for NPP primary circuit leakage monitoring are also given

  15. Progress in Investigation of WWER-440 Reactor Pressure Vessel Steel by Gamma and Moessbauer Spectroscopy

    International Nuclear Information System (INIS)

    Hascik, J.; Slugen, V.; Lipka, J.; Hinca, R.; Toth, I.; Groene, R.; Uvacik, P.; Kupca, L.

    1998-01-01

    Gamma spectroscopic analyse and first experimental results of original irradiated reactor pressure vessel surveillance specimens are discussed in. In 1994, the new ''Extended Surveillance Specimen Program for nuclear Reactor Material Study'' was started in collaboration with the nuclear power plants (NPP) V-2 Bohunice (Slovakia). The first batch of MS samples (after 1 year, which is equivalent to 5 years of loading RPV-steel) was measured and interpreted using the new four components approach with the aim to observe microstructural changes due to thermal and neutron treatment resulting from operating conditions in NPP. The systematic changes in the relative areas of Moessbauer spectra components were observed. (author)

  16. Regridded Harmonized World Soil Database v1.2

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set describes select global soil parameters from the Harmonized World Soil Database (HWSD) v1.2, including additional calculated parameters such as area...

  17. Accident localization system with jet condensers for VVER 440-V 230 NPP at Jaslovske Bohunice

    International Nuclear Information System (INIS)

    Murani, J.

    1995-01-01

    The operational safety of the V1 nuclear power plant (NPP) is unsatisfactory and does not correspond to present requirements as to nuclear safety. Further NPP operation after 1995 is conditional on nuclear safety enhancement to a level comparable with that in West European countries. This aim should be achieved by a principal reconstruction involving in addition to others also backfitting the V1 NPP with technical facilities aimed at coping with a design basis accident (DBA).To cope with such an accident the Power Equipment Research Institute (VUEZ) designed an accident localization system with jet condensers. This system consists of (a) an air trap (one for each unit, mutually interconnected) with an expansion bell enclosed within, placed on a plate with 200 pipes of jet condensers passing through, and (b) a connecting duct between the hermetic zone and the air trap. The vertical jet condenser is an essential element of the system designed for steam condensation. Apart from condensation it serves as a water seal separating units 1 and 2.Demonstration tests of the jet condenser (model 1:1) condensing function were carried out at the testing unit of the All-Union Research Institute for NPP Operation (VNIIAES), Moscow in Kashir, 11-22 September 1992. These experiments proved the jet condenser ability to ensure complete condensation of the steam produced. Experimental verification of the sealing function (model 1:1) was carried out at the testing unit of the VUEZ Tlmace. These experiments concerning the dynamics and overpressure in the free space above the pool were close to the conditions in the air trap during DBA. The jet condenser height was proved to be sufficient to ensure the sealing function. Design and experimental work has been implemented in close cooperation with Russian experts Mr. V.N. Bulynin from the VNIIAES, Moscow, and Mr. M.V. Kuznecov from the Scientific and Engineering Center for Nuclear and Radiological Safety, Moscow. (orig.)

  18. Synaptic Correlates of Low-Level Perception in V1.

    Science.gov (United States)

    Gerard-Mercier, Florian; Carelli, Pedro V; Pananceau, Marc; Troncoso, Xoana G; Frégnac, Yves

    2016-04-06

    The computational role of primary visual cortex (V1) in low-level perception remains largely debated. A dominant view assumes the prevalence of higher cortical areas and top-down processes in binding information across the visual field. Here, we investigated the role of long-distance intracortical connections in form and motion processing by measuring, with intracellular recordings, their synaptic impact on neurons in area 17 (V1) of the anesthetized cat. By systematically mapping synaptic responses to stimuli presented in the nonspiking surround of V1 receptive fields, we provide the first quantitative characterization of the lateral functional connectivity kernel of V1 neurons. Our results revealed at the population level two structural-functional biases in the synaptic integration and dynamic association properties of V1 neurons. First, subthreshold responses to oriented stimuli flashed in isolation in the nonspiking surround exhibited a geometric organization around the preferred orientation axis mirroring the psychophysical "association field" for collinear contour perception. Second, apparent motion stimuli, for which horizontal and feedforward synaptic inputs summed in-phase, evoked dominantly facilitatory nonlinear interactions, specifically during centripetal collinear activation along the preferred orientation axis, at saccadic-like speeds. This spatiotemporal integration property, which could constitute the neural correlate of a human perceptual bias in speed detection, suggests that local (orientation) and global (motion) information is already linked within V1. We propose the existence of a "dynamic association field" in V1 neurons, whose spatial extent and anisotropy are transiently updated and reshaped as a function of changes in the retinal flow statistics imposed during natural oculomotor exploration. The computational role of primary visual cortex in low-level perception remains debated. The expression of this "pop-out" perception is often assumed

  19. Liquid concrete mixes for V-2 nuclear power plant at Jaslovske Bohunice

    International Nuclear Information System (INIS)

    Valenta, D.; Oravec, J.

    1983-01-01

    The liquid concrete mixes consist of aggregates, cement, water and plastifiers. The main component of aggregates is redeposited dolomite from the Dolinka locality and sand. Cement of the SPC-325 type is used while mixing water is taken from the service water pump station for the V-1 nuclear power plant. All concretes used for the V-2 nuclear power plant construction are treated using plastifier Plastifikator S. In concrete mix development, care was primarily taken to select sand with sufficient amounts of grain of a size up to 0.25 mm. Granularity curves of the sands and the resulting curve of the aggregates granularity of the concrete mix are shown graphically. The method of manufacture and conveying of concrete mixes are briefly described. The mathematical statistical analysis of the quality of the concrete mixes produced showed that the proposed concrete mixes meet the requirements for homogeneity in the controlled parameters and that they can be manufactured in the situation of building production provided suitable components are selected, suitable aggregates are available and the quality of production is systematically checked. (J.P.)

  20. Comet P/2010 V1 as a Natural Disintegration Laboratory

    Science.gov (United States)

    Jewitt, David; Weaver, Harold A.; Mutchler, Maximilian J.; Agarwal, Jessica; Meech, Karen Jean; Li, Jing; Kleyna, Jan; Ishiguro, Masateru; Wainscoat, Richard J.; Hui, Man-To

    2016-10-01

    Discovered in outburst in 2010, Jupiter-family comet P/2010 V1 (Ikeya-Murukami) was found to be split in observations at the end of 2015. We used the Hubble Space Telescope to obtain deep images of P/2010 V1 at high angular resolution in the 2016 January to March period. The resulting data, by far the best yet obtained for any split or disrupting comet, show the astrometric, photometric and morphological evolution of about 30 fragments. We will present the first results for the velocity dispersion, photometric distribution and variability and discuss the measurements in terms of models for the breakup.

  1. Masking interrupts figure-ground signals in V1.

    Science.gov (United States)

    Lamme, Victor A F; Zipser, Karl; Spekreijse, Henk

    2002-10-01

    In a backward masking paradigm, a target stimulus is rapidly (figure-ground segregation can be recorded. Here, we recorded from awake macaque monkeys, engaged in a task where they had to detect figures from background in a pattern backward masking paradigm. We show that the V1 figure-ground signals are selectively and fully suppressed at target-mask intervals that psychophysically result in the target being invisible. Initial response transients, signalling the features that make up the scene, are not affected. As figure-ground modulations depend on feedback from extrastriate areas, these results suggest that masking selectively interrupts the recurrent interactions between V1 and higher visual areas.

  2. Backfitting of the nuclear plant V1 power control system

    International Nuclear Information System (INIS)

    Karpeta, C.; Rubek, J.; Stirsky, P.

    1985-01-01

    The paper deals with some aspects of implementation of modifications into the Czechoslovak nuclear plant V1 control system as called for on the basis of experience gained during the first period of the plant operation. Brief description of the plant power control system and its main functions is given. Some deficiencies in the system performance during abnormal conditions are outlined and measures taken to overcome them are presented. (author)

  3. The graphical user interface for CRISTAL V1

    International Nuclear Information System (INIS)

    Heulers, L.; Courtois, G.; Fernex, F.; Gomit, J.M.; Letang, E.

    2003-01-01

    This paper deals with the new Graphical User Interface (GUI) of the CRISTAL V1 package devoted to criticality studies including burn up calculations. The aim of this GUI is to offer users a high level of user-friendliness and flexibility in the data description and the results analysis of codes of the package. The three main components of the GUI (CIGAIES, EJM and OPOSSUM) are presented. The different functionalities of the tools are explained through some applications. (author)

  4. CRISTAL V1: Criticality package for burn up credit calculations

    International Nuclear Information System (INIS)

    Gomit, Jean-Michel; Cousinou, Patrick; Gantenbein, Francoise; Diop, Cheikh; Fernandez de Grado, Guy; Mijuin, Dominique; Grouiller, Jean-Paul; Marc, Andre; Toubon, Herve

    2003-01-01

    The first version of the CRISTAL package, created and validated as part of a joint project between IRSN, COGEMA and CEA, was delivered to users in November 1999. This fruitful cooperation between IRSN, COGEMA and CEA has been pursued until 2003 with the development and the validation of the package CRISTAL V1, whose main objectives are to improve the criticality safety studies including the Burn up Credit effect. (author)

  5. METEOR v1.0 - A usage example

    International Nuclear Information System (INIS)

    Palomo, E.

    1994-01-01

    This script describes a detailed example of the use of the software package METEOR for statistical analysis of meteorological data series. A real spanish meteorological data set is chosen to show the capabilities of METEOR. Output files and resultant plots provided of their interpretations are compiled in three appendixes. The original version of METEOR have been developed by Ph. D.Elena Palomo, CIEMAT-IER, GIASE. It is built by linking programs and routines written in FORTRAN 77 and it adds the graphical capabilities of GNUPLOT. The shape of this toolbox was designed following the criteria of modularity, flexibility and agility criteria. All the input, output and analysis options are structured in three main menus: i) the first is aimed to evaluate the quality of the data set; ii) the second is aimed for pre-processing of the data; and iii) the third is aimed towards the statistical analyses and for creating the graphical outputs. Actually the information about METEOR is constituted by three documents written is spanish: 1) METEOR v1.0: User's guide; 2) METEOR v1.0: A usage example; 3) METEOR v1 .0: Design and structure of the software package. (Author)

  6. Assessment of ICARE/CATHARE V1mod1 and V1 applications to full scale studies

    International Nuclear Information System (INIS)

    Chatelard, P.; Barre, F.; Mutelle, H.

    2001-01-01

    The objective initially assigned to the ICARE/CATHARE V1mod1 validation task was to draw a synthesis of the ability of the code to correctly reproduce the main physical processes occurring during severe accidents. Therefore, both the domain in which the ICARE/CATHARE V1mod1 predictions are satisfactory (good confidence level) and, conversely, the identification of the main code deficiencies have to be highlighted. After a brief recall of the validation strategy and the current status of the work, this paper summarizes the main lessons which were drawn by IPSN from the validation activity which was conducted during the last two years (in 2000-2001) in the particular framework of the Users' Club (both IPSN and several foreign partners were involved in this task, under the management of IPSN). (authors)

  7. METEOR v1.0 - A usage example; METEOR v1.0 - Un ejemplo de uso

    Energy Technology Data Exchange (ETDEWEB)

    Palomo, E.

    1994-07-01

    This script describes a detailed example of the use of the software package METEOR for statistical analysis of meteorological data series. A real spanish meteorological data set is chosen to show the capabilities of METEOR. Output files and resultant plots provided of their interpretations are compiled in three appendixes. The original version of METEOR have been developed by Ph. D.Elena Palomo, CIEMAT-IER, GIASE. It is built by linking programs and routines written in FORTRAN 77 and it adds the graphical capabilities of GNUPLOT. The shape of this toolbox was designed following the criteria of modularity, flexibility and agility criteria. All the input, output and analysis options are structured in three main menus: i) the first is aimed to evaluate the quality of the data set; ii) the second is aimed for pre-processing of the data; and iii) the third is aimed towards the statistical analyses and for creating the graphical outputs. Actually the information about METEOR is constituted by three documents written is spanish: 1) METEOR v1.0: User's guide; 2) METEOR v1.0: A usage example; 3) METEOR v1 .0: Design and structure of the software package. (Author)

  8. METEOR v1.0 - User's Guide; METEOR v1.0 - Guia de Usuarios

    Energy Technology Data Exchange (ETDEWEB)

    Palomo, E.

    1994-07-01

    This script is a User's Guide for the software package METEOR for statistical analysis of meteorological data series. The original version of METEOR have been developed by Ph.D. Elena Palomo, CIEMAT-IER, GIMASE. It is built by linking programs and routines written in FORTRAN 77 and it adds the graphical capabilities of GNUPLOT. The shape of this toolbox was designed following the criteria of modularity, flexibility and agility criteria. All the input, output and analysis options are structured in three main menus: i) the first is aimed to evaluate the quality of the data set; ii) the second is aimed for pre-processing of the data; and iii) the third is aimed towards the statistical analyses and for creating the graphical outputs. Actually the information about METEOR is constituted by three documents written in spanish: 1) METEOR v1.0: User's guide; 2) METEOR v1.0: A usage example; 3) METEOR v1.0: Design and structure of the software package. (Author)

  9. Homoeologous Recombination of the V1r1-V1r2 Gene Cluster of Pheromone Receptors in an Allotetraploid Lineage of Teleosts

    Directory of Open Access Journals (Sweden)

    Lei Zhong

    2017-11-01

    Full Text Available In contrast to other olfactory receptor families that exhibit frequent lineage-specific expansions, the vomeronasal type 1 receptor (V1R family exhibits a canonical six-member repertoire in teleosts. V1r1 and V1r2 are present in no more than one copy in all examined teleosts, including salmons, which are ancient polyploids, implying strict evolutionary constraints. However, recent polyploids have not been examined. Here, we identified a young allotetraploid lineage of weatherfishes and investigated their V1r1-V1r2 cluster. We found a novel pattern that the parental V1r1-V1r2 clusters had recombined in the tetraploid genome and that the recombinant was nearly fixed in the tetraploid population. Subsequent analyses suggested strong selective pressure, for both a new combination of paralogs and homogeneity among gene duplicates, acting on the V1r1-V1r2 pair.

  10. TASS code topical report. V.1 TASS code technical manual

    International Nuclear Information System (INIS)

    Sim, Suk K.; Chang, W. P.; Kim, K. D.; Kim, H. C.; Yoon, H. Y.

    1997-02-01

    TASS 1.0 code has been developed at KAERI for the initial and reload non-LOCA safety analysis for the operating PWRs as well as the PWRs under construction in Korea. TASS code will replace various vendor's non-LOCA safety analysis codes currently used for the Westinghouse and ABB-CE type PWRs in Korea. This can be achieved through TASS code input modifications specific to each reactor type. The TASS code can be run interactively through the keyboard operation. A simimodular configuration used in developing the TASS code enables the user easily implement new models. TASS code has been programmed using FORTRAN77 which makes it easy to install and port for different computer environments. The TASS code can be utilized for the steady state simulation as well as the non-LOCA transient simulations such as power excursions, reactor coolant pump trips, load rejections, loss of feedwater, steam line breaks, steam generator tube ruptures, rod withdrawal and drop, and anticipated transients without scram (ATWS). The malfunctions of the control systems, components, operator actions and the transients caused by the malfunctions can be easily simulated using the TASS code. This technical report describes the TASS 1.0 code models including reactor thermal hydraulic, reactor core and control models. This TASS code models including reactor thermal hydraulic, reactor core and control models. This TASS code technical manual has been prepared as a part of the TASS code manual which includes TASS code user's manual and TASS code validation report, and will be submitted to the regulatory body as a TASS code topical report for a licensing non-LOCA safety analysis for the Westinghouse and ABB-CE type PWRs operating and under construction in Korea. (author). 42 refs., 29 tabs., 32 figs

  11. SIGMA Release v1.2 - Capabilities, Enhancements and Fixes

    Energy Technology Data Exchange (ETDEWEB)

    Mahadevan, Vijay [Argonne National Lab. (ANL), Argonne, IL (United States); Grindeanu, Iulian R. [Argonne National Lab. (ANL), Argonne, IL (United States); Ray, Navamita [Argonne National Lab. (ANL), Argonne, IL (United States); Jain, Rajeev [Argonne National Lab. (ANL), Argonne, IL (United States); Wu, Danqing [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-09-30

    In this report, we present details on SIGMA toolkit along with its component structure, capabilities, and feature additions in FY15, release cycles, and continuous integration process. These software processes along with updated documentation are imperative to successfully integrate and utilize in several applications including the SHARP coupled analysis toolkit for reactor core systems funded under the NEAMS DOE-NE program.

  12. SIGMA Release v1.2 - Capabilities, Enhancements and Fixes

    International Nuclear Information System (INIS)

    Mahadevan, Vijay; Grindeanu, Iulian R.; Ray, Navamita; Jain, Rajeev; Wu, Danqing

    2015-01-01

    In this report, we present details on SIGMA toolkit along with its component structure, capabilities, and feature additions in FY15, release cycles, and continuous integration process. These software processes along with updated documentation are imperative to successfully integrate and utilize in several applications including the SHARP coupled analysis toolkit for reactor core systems funded under the NEAMS DOE-NE program.

  13. Fatigue of materials and structures. v. 1,2

    International Nuclear Information System (INIS)

    1989-01-01

    Published in two volumes, the conference proceedings contain 82 contributions, 9 of which have been inputted in INIS. These were concerned with the measurement and evaluation of fatigue characteristics during low-cycle load of materials such as steels for nuclear reactor pressure vessels and other components. (B.S.)

  14. Attention and normalization circuits in macaque V1

    Science.gov (United States)

    Sanayei, M; Herrero, J L; Distler, C; Thiele, A

    2015-01-01

    Attention affects neuronal processing and improves behavioural performance. In extrastriate visual cortex these effects have been explained by normalization models, which assume that attention influences the circuit that mediates surround suppression. While normalization models have been able to explain attentional effects, their validity has rarely been tested against alternative models. Here we investigate how attention and surround/mask stimuli affect neuronal firing rates and orientation tuning in macaque V1. Surround/mask stimuli provide an estimate to what extent V1 neurons are affected by normalization, which was compared against effects of spatial top down attention. For some attention/surround effect comparisons, the strength of attentional modulation was correlated with the strength of surround modulation, suggesting that attention and surround/mask stimulation (i.e. normalization) might use a common mechanism. To explore this in detail, we fitted multiplicative and additive models of attention to our data. In one class of models, attention contributed to normalization mechanisms, whereas in a different class of models it did not. Model selection based on Akaike's and on Bayesian information criteria demonstrated that in most cells the effects of attention were best described by models where attention did not contribute to normalization mechanisms. This demonstrates that attentional influences on neuronal responses in primary visual cortex often bypass normalization mechanisms. PMID:25757941

  15. Attention and normalization circuits in macaque V1.

    Science.gov (United States)

    Sanayei, M; Herrero, J L; Distler, C; Thiele, A

    2015-04-01

    Attention affects neuronal processing and improves behavioural performance. In extrastriate visual cortex these effects have been explained by normalization models, which assume that attention influences the circuit that mediates surround suppression. While normalization models have been able to explain attentional effects, their validity has rarely been tested against alternative models. Here we investigate how attention and surround/mask stimuli affect neuronal firing rates and orientation tuning in macaque V1. Surround/mask stimuli provide an estimate to what extent V1 neurons are affected by normalization, which was compared against effects of spatial top down attention. For some attention/surround effect comparisons, the strength of attentional modulation was correlated with the strength of surround modulation, suggesting that attention and surround/mask stimulation (i.e. normalization) might use a common mechanism. To explore this in detail, we fitted multiplicative and additive models of attention to our data. In one class of models, attention contributed to normalization mechanisms, whereas in a different class of models it did not. Model selection based on Akaike's and on Bayesian information criteria demonstrated that in most cells the effects of attention were best described by models where attention did not contribute to normalization mechanisms. This demonstrates that attentional influences on neuronal responses in primary visual cortex often bypass normalization mechanisms. © 2015 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  16. Activity report on neutron scattering research. V. 1, 1994

    International Nuclear Information System (INIS)

    Fujii, Y.; Oohara, Y.

    1994-09-01

    In April, 1993, the Neutron Scattering Laboratory attached to the Institute for Solid State Physics, University of Tokyo, was newly established in Tokai, Ibaraki Prefecture, to promote nationwide users' programs for utilizing the university-owned neutron instruments installed at the JRR-3M reactor of Japan Atomic Energy Research Institute. This upgraded reactor (20 MW, the cold source is installed) has drastically expanded the number of users and research areas since 1990 when it became operational. Currently 8 and 3 out of 18 new spectrometers in total at the JRR-3M are owned by ISSP and Tohoku University, respectively, while the remaining 7 spectrometers belong to JAERI. In addition, 3 conventional spectrometers in the 30 years old JRR-2 reactor (10 MW) have also supported research activities. This is the first issue of 'Activity report on neutron scattering research', and it is to be published annually. In this report, the brief history of neutron scattering research, the users' programs, the committees, the neutron scattering instruments available at the JRR-3M and the JRR-2M, the activity reports on structures and excitation, magnetism, superconductors, liquid and glass, material science, polymers, biology and instrumentation, and publication list are reported. (K.I.)

  17. SIEMENS

    International Nuclear Information System (INIS)

    2001-01-01

    This CD is multimedia presentation of programme safety upgrading of Bohunice V1 NPP. This chapter contains information about Siemens and it participation on reconstruction of Bohunice V1 and V1 NPPs. It consists of next parts: (1) FRAMATOME ANP - worldwide activities of the FRAMATOME are presented; (2) Nuclear power engineering - present activities focus on: Upgrading and Backfitting (Siemens WWER activities since 1971); Electrical instrumentation and control systems; Fuel assemblies and related services; Reactor development and construction of new plants; (3) Safety improvement; (4) Siemens in Slovakia (activities of Siemens in Slovakia during 1993-2000 are presented); (5) More than 150-year history

  18. Collinear integration affects visual search at V1.

    Science.gov (United States)

    Chow, Hiu Mei; Jingling, Li; Tseng, Chia-huei

    2013-08-29

    Perceptual grouping plays an indispensable role in figure-ground segregation and attention distribution. For example, a column pops out if it contains element bars orthogonal to uniformly oriented element bars. Jingling and Tseng (2013) have reported that contextual grouping in a column matters to visual search behavior: When a column is grouped into a collinear (snakelike) structure, a target positioned on it became harder to detect than on other noncollinear (ladderlike) columns. How and where perceptual grouping interferes with selective attention is still largely unknown. This article contributes to this little-studied area by asking whether collinear contour integration interacts with visual search before or after binocular fusion. We first identified that the previously mentioned search impairment occurs with a distractor of five or nine elements but not one element in a 9 × 9 search display. To pinpoint the site of this effect, we presented the search display with a short collinear bar (one element) to one eye and the extending collinear bars to the other eye, such that when properly fused, the combined binocular collinear length (nine elements) exceeded the critical length. No collinear search impairment was observed, implying that collinear information before binocular fusion shaped participants' search behavior, although contour extension from the other eye after binocular fusion enhanced the effect of collinearity on attention. Our results suggest that attention interacts with perceptual grouping as early as V1.

  19. Control of WWER-440 nuclear reactor

    International Nuclear Information System (INIS)

    Wagner, K.; Drab, F.; Grof, V.

    1978-01-01

    The V-1 reactor control systems are described. The data acquisition and processing system fulfils four main functions, ie., reactor start-up and power increase to 10% of the rated power, automatic power control within 3% and 110% of the rated power, reactivity compensation, and reactor protection. The automatic control system ensures constant steam pressure maintained with an accuracy of +-0.05 MPa. Reactivity compensation and spatial power distribution is mainly safeguarded by boric acid control. The V-1 reactor protection system has four levels of accident protection depending on the gravity of the failure. The philosophy of automation of the V-1 reactor control and protection system is based on autonomous automatic controlers and on the direct control of the individual sets and technological equipment. In conclusion, development trends are briefly outlined of control and protection systems of light water reactor power plants. (Z.M.)

  20. Radioactive waste management at WWER type reactors

    International Nuclear Information System (INIS)

    1993-05-01

    This report was prepared within the framework of the Technical Assistance Regional Project on Advice on Waste Management at WWER Type Reactors, which was initiated by the IAEA in 1991. The Regional Project is an integral part of the IAEA's activities directed towards improvement of the safety and reliability of nuclear power plants with WWER type reactors (Soviet designed PWRs). Forty-five WWER type units are currently in operation and twenty-five are under construction in Bulgaria, Czechoslovakia, Finland, Hungary and the former USSR. The idea of regional collaboration between eastern European countries under the auspices of the IAEA was discussed for the first time during the last meeting of the Council for Mutual Economic Assistance (CMEA) on spent fuel and radioactive waste management, held in Rez, Czechoslovakia, in October 1990. Since then, the CMEA and some of its former Member States have ceased to exist. However, there are many reasons for eastern European countries to continue their regional collaboration at a higher level. The USSR, the designer and supplier of WWER type reactors in eastern European countries, participated in the first phase of the project. The majority of WWER type reactors are situated in States of the former USSR (Russia and Ukraine). The main results of the first phase of the Regional Project are: (i) Re-establishment of communication channels among eastern European countries operating WWER type reactors by incorporating the IAEA's technical assistance; (ii) Identification of common waste management problems (administrative and technical) requiring resolution; (iii) Familiarization with radioactive waste management systems at nuclear power plants with WWER type reactors - Paks (Hungary), Loviisa (Finland), Jaslovske Bohunice (Czechoslovakia) and Novovoronezh (Russian Federation). Tabs

  1. DeCART v1.2 User's Manual

    International Nuclear Information System (INIS)

    Cho, J. Y.; Kim, K. S.; Kim, H. Y.; Lee, C. C.; Zee, S. Q; Joo, H. G.

    2007-07-01

    DeCART (Deterministic Core Analysis based on Ray Tracing) is a whole core neutron transport code capable of direct subpin level flux calculation at power generating conditions. It does not require a priori homogenization nor group condensation needed in conventional reactor physics calculations. The depletion and transient calculation capabilities are also available. This manual serves as a self-sufficient guide to use the code. First of all, the various features of the code are explained which encompass various modeling options as well as the basic calculation functionalities. The instructions for running the code are also given with a description of the output files generated. Next, the underlying concepts and principles of preparing a DeCART model for a problem under consideration are presented. Each part of the input needed to specify the geometry, material composition, thermal operating condition, program execution control parameters are explained with examples. The descriptions of all the input cards are then followed. Finally, various sample model inputs ranging from a simple 2D pin cell to a realistic 3D core problem, steady-state to transient problems, and from rectangular to hexagonal core problems are presented

  2. DeCART v1.1 user's manual

    International Nuclear Information System (INIS)

    Cho, J. Y.; Kim, K. S.; Kim, H. Y.; Lee, C. C.; Zee, S. Q.; Joo, H. G.

    2005-03-01

    DeCART (Deterministic Core Analysis based on Ray Tracing) is a whole core neutron transport code capable of direct subpin level flux calculation at power generating conditions. It does not require a priori homogenization nor group condensation needed in conventional reactor physics calculations. The depletion and transient calculation capabilities are also available. This manual serves as a self-sufficient guide to use the code. First of all, the various features of the code are explained which encompass various modeling options as well as the basic calculation functionalities. The instructions for running the code are also given with a description of the output files generated. Next, the underlying concepts and principles of preparing a DeCART model for a problem under consideration are presented. Each part of the input needed to specify the geometry, material composition, thermal operating condition, program execution control parameters are explained with examples. The descriptions of all the input cards are then followed. Finally, various sample model inputs ranging from a simple 2D pin cell to a realistic 3D core problem, steady-state to transient problems, are presented

  3. Polarized expression of the GFP-tagged rat V(1a) vasopressin receptor.

    Science.gov (United States)

    Campos, D M; Reyes, C E; Sarmiento, J; Navarro, J; González, C B

    2001-11-30

    We investigated the targeting of the V(1a) receptor fused with the green fluorescence protein (V(1a)R-GFP) in polarized MDCK cells. Cells expressing V(1a)R-GFP displayed binding to vasopressin (AVP) and AVP-induced calcium responses, similar to cells expressing the wild-type V1a receptor. Interestingly, as with the wild-type V(1a)R, V(1a)R-GFP is preferentially distributed in the basolateral side of MDCK cells as monitored by confocal microscopy. Furthermore, AVP induced internalization of GFP-tagged receptors. Therefore, the GFP-tagged V(1a) receptor retains all the sorting signals of the wild-type receptor and offers an excellent system to elucidate the mechanisms of cell trafficking of V(1a) receptors.

  4. Validation of ASTEC v1.0 computer code against FPT2 test

    International Nuclear Information System (INIS)

    Mladenov, I.; Tusheva, P.; Kalchev, B.; Dimov, D.; Ivanov, I.

    2005-01-01

    The aim of the work is by various nodalization schemes of the model to investigate the ASTEC v1.0 computer code sensitivity and to validate the code against PHEBUS - FPT2 experiment. This code is used for severe accident analysis. The aim corresponds to the main technical objective of the experiment which is to contribute to the validation of models and computer codes to be used for the calculation of the source term in case of a severe accident in a Light Water Reactor. The objective's scope of the FPT2 is large - separately for the bundle, the experimental circuit and the containment. Additional objectives are to characterize aerosol sizing and deposition processes, and also potential FP poisoning effects on hydrogen recombiner coupons exposed to containment atmospheric conditions representative of a LWR severe accident. The analyses of the results of the performed calculations show a good accordance with the reference case calculations, and then with the experimental data. Some differences in the calculations for the thermal behavior appear locally during the oxidation phase and the heat-up phase. There is very good confirmation regarding the volatile and semi-volatile fission products release from the fuel pellets. Important for analysis of the process is the final axial distribution of the mass of fuel relocation obtained at the end of the calculation

  5. Reliability analysis of self-supply system of V-1 nuclear power plant

    International Nuclear Information System (INIS)

    Kuklik, B.

    The results are summarized of the fault tree analysis of the V-1 power plant self-consumption system. The 6 kV busbars providing power for the main circulating pumps, the steam generator feed pumps and other important components including the 0.4 kV busbars are of the highest importance for nuclear safety. A fault tree analysis was also made of the emergency core cooling system of the reactor. Dangerous faults are defined and fault trees are developed. A brief description is given of the calculation algorithm for a digital computer. Some results are discussed. The calculated reliability of the emergency core cooling system is 10 5 years, of the 6 kV busbars it is 6.6x10 4 years. In case of a permanent or a long-term outage of the 220 kV stand-bye power supply, the system reliability is reduced to 7x10 2 years. (Z.M.)

  6. Reconstruction of instrumentation and control system (SKR)

    International Nuclear Information System (INIS)

    Wiening, K.-H.

    2001-01-01

    For the first time extensive upgrades have been performed in all safety related areas of units with WWER 440/230 reactors. One of the most important actions was the replacement of the safety and safety related instrumentation and control. The state of the art digital safety instrumentation and control system TELEPERM XS has been implemented in units 1 and 2 of the Bohunice V1 power plant. The requirements as deduced from safety assessments conducted by commissions of international experts have been fulfilled, so that Bohunice V1 after this gradual reconstruction has been upgraded to an internationally accepted safety level for the remainder of its service life. (author)

  7. Calculation of radiation dose rate above water layer of Interim Spent Fuel Storage Jaslovske Bohunice by the point Kernels (VISIPLAN) and Monte Carlo (MCNP4C) methods

    International Nuclear Information System (INIS)

    Slavik, O.; Kucharova, D.; Listjak, M.; Fueloep, M.

    2008-01-01

    The aim of this paper is to evaluate maximal dose rate (DR) of gamma radiation above different configurations of reservoirs with spent nuclear fuel with cooling period 1.8 year and to compare by buildup factor method (Visiplan) and Monte Carlo simulations and to appreciate influence of scattered photons in the case of calculation of fully filled fuel transfer storage (FTS). On the ground of performed accounts it was shown, that relative contributions of photons from adjacent reservoirs are in the case buildup factor method (Visiplan) similar to Monte Carlo simulations. It means, that Visiplan can be used also for valuation of contributions of of dose rates from neighbouring reservoirs. It was shown, that calculations of DR by Visiplan are conservatively overestimated for this source of radiation and thickness of shielding approximately 2.6 - 3 times. Also following these calculations resulted, that by storage of reservoirs with cooling period 1.8 years in FTS is not needed any additional protection measures for workers against primal safety report. Calculated DR also above fully filled FTS by these reservoirs in Jaslovske Bohunice is very low on the level 0.03 μSv/h. (authors)

  8. Calculation of radiation dose rate above water layer of Interim Spent Fuel Storage Jaslovske Bohunice by the point Kernels (VISIPLAN) and Monte Carlo (MCNP4C) methods

    International Nuclear Information System (INIS)

    Slavik, O.; Kucharova, D.; Listjak, M.; Fueloep, M.

    2009-01-01

    The aim of this paper is to evaluate maximal dose rate (DR) of gamma radiation above different configurations of reservoirs with spent nuclear fuel with cooling period 1.8 year and to compare by buildup factor method (Visiplan) and Monte Carlo simulations and to appreciate influence of scattered photons in the case of calculation of fully filled fuel transfer storage (FTS). On the ground of performed accounts it was shown, that relative contributions of photons from adjacent reservoirs are in the case buildup factor method (Visiplan) similar to Monte Carlo simulations. It means, that Visiplan can be used also for valuation of contributions of of dose rates from neighbouring reservoirs. It was shown, that calculations of DR by Visiplan are conservatively overestimated for this source of radiation and thickness of shielding approximately 2.6 - 3 times. Also following these calculations resulted, that by storage of reservoirs with cooling period 1.8 years in FTS is not needed any additional protection measures for workers against primal safety report. Calculated DR also above fully filled FTS by these reservoirs in Jaslovske Bohunice is very low on the level 0.03 μSv/h. (authors)

  9. NPP Mochovce - a project of extraordinay significance

    International Nuclear Information System (INIS)

    Chwolik, I.; Debru, M.

    2000-01-01

    In this paper and in this presentation the reactor safety upgrading of two blocks of the NPP V-1 Bohunice, some results of participation on safety upgrading by the German-French consortium EUCOM (Framatome and Siemens-KWU) are presented. (author)

  10. Proceedings of the 2. General Congress of Nuclear Energy - v.1

    International Nuclear Information System (INIS)

    1988-01-01

    The papers arranged in the following fields: safety analysis and licensing; reactor physics; nuclear physics; reactor operation; reactor engineering and nuclear fuel analysis; scince and technology of materials; and thermohydraulic, are presented. (M.C.K.) [pt

  11. Ultrasound periodic inspections of reactor pressure vessels

    International Nuclear Information System (INIS)

    Haniger, L.

    1980-01-01

    Two versions are described of ultrasonic equipment for periodic inspections of reactor pressure vessels. One uses the principle of exchangeable programmators with solid-state logic while the other uses programmable logic with semiconductor memories. The equipment is to be used for inspections of welded joints on the upper part of the V-1 reactor pressure vessel. (L.O.)

  12. POSTNATAL PHENOTYPE AND LOCALIZATION OF SPINAL CORD V1 DERIVED INTERNEURONS

    Science.gov (United States)

    Alvarez, Francisco J.; Jonas, Philip C.; Sapir, Tamar; Hartley, Robert; Berrocal, Maria C.; Geiman, Eric J.; Todd, Andrew J.; Goulding, Martyn

    2010-01-01

    Developmental studies identified four classes (V0, V1, V2, V3) of embryonic interneurons in the ventral spinal cord. Very little however is known about their adult phenotypes. In order to further characterize interneuron cell types in the adult, the location, neurotransmitter phenotype, calcium-buffering protein expression and axon distributions of V1-derived neurons in the mouse spinal cord was determined. In the mature (P20 and older) spinal cord, most V1-derived neurons are located in lateral LVII and in LIX, few in medial LVII and none in LVIII. Approximately 40% express calbindin and/or parvalbumin, while few express calretinin. Of seven groups of ventral interneurons identified according to calcium-buffering protein expression, two groups (1 and 4) correspond with V1-derived neurons. Group 1 are Renshaw cells and intensely express calbindin and coexpress parvalbumin and calretinin. They represent 9% of the V1 population. Group 4 express only parvalbumin and represent 27% of V1-derived neurons. V1-derived group 4 neurons receive contacts from primary sensory afferents and are therefore proprioceptive interneurons and the most ventral neurons in this group receive convergent calbindin-IR Renshaw cell inputs. This subgroup resembles Ia inhibitory interneurons (IaINs) and represents 13% of V1-derived neurons. Adult V1-interneuron axons target LIX and LVII and some enter the deep dorsal horn. V1-axons do not cross the midline. V1 derived axonal varicosities were mostly (>80%) glycinergic and a third were GABAergic. None were glutamatergic or cholinergic. In summary, V1 interneurons develop into ipsilaterally projecting, inhibitory interneurons that include Renshaw cells, Ia inhibitory interneurons and other unidentified proprioceptive interneurons. PMID:16255029

  13. Comparison of experimental and theoretical integral cross sections for D+H2(v=1, j=1)→HD(v'=1, j')+H

    International Nuclear Information System (INIS)

    Kliner, D.A.V.; Adelman, D.E.; Zare, R.N.

    1991-01-01

    We have measured the nascent HD(v'=1, j') product rotational distribution from the reaction D+H 2 (v, j) in which the H 2 reagent was either thermal (v=0, j) or prepared in the level (v=1, j=1) by stimulated Raman pumping. Translationally hot D atoms were obtained by uv laser photolysis of DBr or DI. Photolysis of DBr generated D atoms with center-of-mass collision energies (E rel ) of 1.04 and 0.82 eV, which corresponded to the production of ground state Br and spin--orbit-excited Br*, respectively. The E rel values for DI photolysis were 1.38 and 0.92 eV. Quantum-state-specific detection of HD was accomplished via (2+1) resonance-enhanced multiphoton ionization and time-of-flight mass spectrometry. Vibrational excitation of the H 2 reagent results in substantial rotational excitation of the HD(v'=1) product and increases the reaction rate into v'=1 by about a factor of 4. Although the quantum-mechanical calculation of Blais et al. [Chem. Phys. Lett. 166, 11 (1990)] for the D+H 2 (v=1, j=1)→HD(v'=1, j')+H product rotational distribution at E rel =1.02 eV is in qualitative agreement with experiment, it does not quantitatively agree with the measured distribution. Specifically, the calculated distribution is too hot by 2--3 rotational quanta, and the predicted enhancement in the v'=1 rate with reagent vibrational excitation is too large by 67%±9

  14. Adaptive gain modulation in V1 explains contextual modifications during bisection learning.

    Directory of Open Access Journals (Sweden)

    Roland Schäfer

    2009-12-01

    Full Text Available The neuronal processing of visual stimuli in primary visual cortex (V1 can be modified by perceptual training. Training in bisection discrimination, for instance, changes the contextual interactions in V1 elicited by parallel lines. Before training, two parallel lines inhibit their individual V1-responses. After bisection training, inhibition turns into non-symmetric excitation while performing the bisection task. Yet, the receptive field of the V1 neurons evaluated by a single line does not change during task performance. We present a model of recurrent processing in V1 where the neuronal gain can be modulated by a global attentional signal. Perceptual learning mainly consists in strengthening this attentional signal, leading to a more effective gain modulation. The model reproduces both the psychophysical results on bisection learning and the modified contextual interactions observed in V1 during task performance. It makes several predictions, for instance that imagery training should improve the performance, or that a slight stimulus wiggling can strongly affect the representation in V1 while performing the task. We conclude that strengthening a top-down induced gain increase can explain perceptual learning, and that this top-down signal can modify lateral interactions within V1, without significantly changing the classical receptive field of V1 neurons.

  15. Report of the IPERS (International Peer Review Service) review mission for the Bohunice-V2 nuclear power plant Level 1 probabilistic safety assessment in the Slovak Republic 17 to 28 January 1995

    International Nuclear Information System (INIS)

    1995-01-01

    This report presents the results of the IAEA International Peer Review Services (IPERS) review of the probabilistic safety assessment (PSA) for the Bohunice-V2 NPP. The review was based on the PSA documentation available and on intensive communications with the analysis team and representatives from the utility and the plant operator. The results presented herein reflect the views of the international experts carrying out the review. They are provided for consideration by the responsible authorities of the Slovak Republic. 12 refs, 4 tabs

  16. In-service materials testing of selected components of unit 1 and 2 of V-1 nuclear power plant

    International Nuclear Information System (INIS)

    Cintula, J.

    1982-01-01

    The task of in-service nondestructive testing of nuclear installations is to confirm that the state of base material and welded joints has not changed owing to mechanical, thermal or radiation stress. Under the regulations of safe operation the first in-service inspection of all components of a WWER 440 reactor must be carried out after 15,000 to 2O,00O operating hours at the latest. Further in-service inspections are repeated after 30,000 hours (pressure vessels) and 40,000 hours (the main steam piping and the feedwater piping). Proceeding from experience gained so far, intervals are suggested for in-service checks of the other components of the V-1 nuclear power plant. Also briefly described are the main nondestructive methods used for such checks at this power plant. (Z.M.)

  17. Validation of CESAR Thermal-hydraulic Module of ASTEC V1.2 Code on BETHSY Experiments

    Science.gov (United States)

    Tregoures, Nicolas; Bandini, Giacomino; Foucher, Laurent; Fleurot, Joëlle; Meloni, Paride

    The ASTEC V1 system code is being jointly developed by the French Institut de Radioprotection et Sûreté Nucléaire (IRSN) and the German Gesellschaft für Anlagen und ReaktorSicherheit (GRS) to address severe accident sequences in a nuclear power plant. Thermal-hydraulics in primary and secondary system is addressed by the CESAR module. The aim of this paper is to present the validation of the CESAR module, from the ASTEC V1.2 version, on the basis of well instrumented and qualified integral experiments carried out in the BETHSY facility (CEA, France), which simulates a French 900 MWe PWR reactor. Three tests have been thoroughly investigated with CESAR: the loss of coolant 9.1b test (OECD ISP N° 27), the loss of feedwater 5.2e test, and the multiple steam generator tube rupture 4.3b test. In the present paper, the results of the code for the three analyzed tests are presented in comparison with the experimental data. The thermal-hydraulic behavior of the BETHSY facility during the transient phase is well reproduced by CESAR: the occurrence of major events and the time evolution of main thermal-hydraulic parameters of both primary and secondary circuits are well predicted.

  18. Design basis and design features of WWER-440 model 213 nuclear power plants. Reference plant: Bohunice V2 (Slovakia)

    International Nuclear Information System (INIS)

    1994-05-01

    The prime objective of the IAEA Technical Co-operation Project on Evaluation of Safety Aspects of WWER-440 model 213 NPPs is to co-ordinate and to integrate assistance to national organizations in studying selected aspects of safety for the same type of reactors. Consequently, the study integrated the results generated by national activities carried out in the Czech Republic, Hungary, Slovakia and Ukraine and co-ordinated through the IAEA. Valuable assistance in carrying out the tasks was also provided by Bulgaria and Poland. A set of publications is being prepared to present the results of the project. The publications are intended to facilitate the review and utilization of the results of the project. They are also providing assistance in further refinement and/or extension of plant specific safety evaluation of model 213 NPPs. This Technical Document addressing the design basis and safety related design features of WWER-440 model 213 plants is the first of the series to be published. It is hoped that this document will be useful to anyone working in the field of WWER safety, and in particular to experts planning, executing or reviewing studies related to the subject. Refs, 36 figs, tabs

  19. Properties of V1 neurons tuned to conjunctions of visual features: application of the V1 saliency hypothesis to visual search behavior.

    Directory of Open Access Journals (Sweden)

    Li Zhaoping

    Full Text Available From a computational theory of V1, we formulate an optimization problem to investigate neural properties in the primary visual cortex (V1 from human reaction times (RTs in visual search. The theory is the V1 saliency hypothesis that the bottom-up saliency of any visual location is represented by the highest V1 response to it relative to the background responses. The neural properties probed are those associated with the less known V1 neurons tuned simultaneously or conjunctively in two feature dimensions. The visual search is to find a target bar unique in color (C, orientation (O, motion direction (M, or redundantly in combinations of these features (e.g., CO, MO, or CM among uniform background bars. A feature singleton target is salient because its evoked V1 response largely escapes the iso-feature suppression on responses to the background bars. The responses of the conjunctively tuned cells are manifested in the shortening of the RT for a redundant feature target (e.g., a CO target from that predicted by a race between the RTs for the two corresponding single feature targets (e.g., C and O targets. Our investigation enables the following testable predictions. Contextual suppression on the response of a CO-tuned or MO-tuned conjunctive cell is weaker when the contextual inputs differ from the direct inputs in both feature dimensions, rather than just one. Additionally, CO-tuned cells and MO-tuned cells are often more active than the single feature tuned cells in response to the redundant feature targets, and this occurs more frequently for the MO-tuned cells such that the MO-tuned cells are no less likely than either the M-tuned or O-tuned neurons to be the most responsive neuron to dictate saliency for an MO target.

  20. Properties of V1 neurons tuned to conjunctions of visual features: application of the V1 saliency hypothesis to visual search behavior.

    Science.gov (United States)

    Zhaoping, Li; Zhe, Li

    2012-01-01

    From a computational theory of V1, we formulate an optimization problem to investigate neural properties in the primary visual cortex (V1) from human reaction times (RTs) in visual search. The theory is the V1 saliency hypothesis that the bottom-up saliency of any visual location is represented by the highest V1 response to it relative to the background responses. The neural properties probed are those associated with the less known V1 neurons tuned simultaneously or conjunctively in two feature dimensions. The visual search is to find a target bar unique in color (C), orientation (O), motion direction (M), or redundantly in combinations of these features (e.g., CO, MO, or CM) among uniform background bars. A feature singleton target is salient because its evoked V1 response largely escapes the iso-feature suppression on responses to the background bars. The responses of the conjunctively tuned cells are manifested in the shortening of the RT for a redundant feature target (e.g., a CO target) from that predicted by a race between the RTs for the two corresponding single feature targets (e.g., C and O targets). Our investigation enables the following testable predictions. Contextual suppression on the response of a CO-tuned or MO-tuned conjunctive cell is weaker when the contextual inputs differ from the direct inputs in both feature dimensions, rather than just one. Additionally, CO-tuned cells and MO-tuned cells are often more active than the single feature tuned cells in response to the redundant feature targets, and this occurs more frequently for the MO-tuned cells such that the MO-tuned cells are no less likely than either the M-tuned or O-tuned neurons to be the most responsive neuron to dictate saliency for an MO target.

  1. A V1-vascular vasopressin antagonist suitable for radioiodination and photoaffinity labeling

    International Nuclear Information System (INIS)

    Thibonnier, M.; Chehade, N.; Hinko, A.

    1990-01-01

    We have previously characterized the V1-vascular arginine vasopressin (AVP) receptors of human platelets. We now report on a radiomonoiodinated and photoreactive V1-vascular AVP antagonist (V1-ag) to be used for the purification of human V1-vascular AVP receptors. The V1-ag, d(CH2)5Tyr(Me)Tyr(NH2)AVP was modified by radiomonoiodination of d(CH2)5-Tyr(Me)Tyr(NH2)AVP with the Iodogen technique, and derivatization of d(CH2)5Tyr(Me)Tyr[125I](NH2)-AVP with the photoreactive crosslinker, N-hydroxysuccinimidyl-4-azidobenzoate (HSAB) (each step included HPLC purification). In competition experiments, the affinity of these V1-ag for the human platelet AVP receptors remained excellent. Irreversible photoaffinity labeling of the platelet V1-vascular AVP receptor was successfully achieved by UV lamp exposure (365 nm, 20 min). Thus, AzBz-d(CH2)5Tyr(Me)Tyr[125I](NH2)AVP is a promising tool to use for the purification of human V1-vascular AVP receptors

  2. Different glutamate receptors convey feedforward and recurrent processing in macaque V1

    NARCIS (Netherlands)

    Self, M.W.; Kooijmans, R.N.; Super, H.; Lamme, V.A.F.; Roelfsema, P.R.

    2012-01-01

    Neurons in the primary visual cortex (V1) receive feedforward input from the thalamus, which shapes receptive-field properties. They additionally receive recurrent inputs via horizontal connections within V1 and feedback from higher visual areas that are thought to be important for conscious visual

  3. USEEIO v1.1 - Elementary Flows and Life Cycle Impact Assessment (LCIA) Characterization Factors

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset is part of the USEEIO v1.1 model release. It provides the elementary flows used in the USEEIO v1.1 Satellite Tables (DOI: 10.23719/1365565) and their...

  4. Chapter No.3. Assessment and inspection of nuclear installations

    International Nuclear Information System (INIS)

    2002-01-01

    The assessment activity of UJD in relation to nuclear installation lies in assessment of safety documentation for constructions realised as nuclear installations, or construction through which changes on nuclear installations are realised. The assessment activity of UJD in 2001 was focused on National Repository of Radwaste in Mochovce, on Radwaste conditioning and treatment technology in Jaslovske Bohunice and on the assessment of documentation for the project of modernisation of Bohunice V-2 NPPs which is under preparation. The assessment of the technical condition of equipment, important in terms of nuclear safety, primarily based on results of in-service inspections and surveillance testing of safety related components and systems, is also a part of the safety assessment of nuclear installation operation. The inspectors take part in training courses and participate in other technical meetings and workshops organised by the IAEA and also take part in special training courses organised by the Nuclear Authorities of European countries, USA and Japan. Bohunice V-1 NPP is equipped with two reactors of WWER 440 type V-230 and was put into operation in 1978-1980 as one of the last nuclear power plants with this type of reactor. Both units of NPP V-1 Bohunice operated in 2001 according to the requirements of energy dispatching at nominal power, or in a regime of tertiary regulation. November 2000, a mission of experts invited by UJD and delegated by IAEA took place at the Bohunice NPPs. The mission members together with experts of the plant operator assessed the safety of the units of WWER-440/V-230 of Bohunice V-1 NPP after the reconstruction. The members of the mission prepared the report on the current status of safety of these units for the IAEA. In 2001, UJD by its decision, issued the approval for further operation of both reactor units of Bohunice V-1 NPP. In sense of the relevant decree on operational events, 20 events have been recorded, at Bohunice V-1 NPP in

  5. Proceedings of the 9th NUSIM 2000 Conference. Joint Slovak, Czech and German Seminar on Nuclear Power

    International Nuclear Information System (INIS)

    2000-01-01

    Scientific conference deals with problems of reactor safety upgrading, mainly of two blocks of the NPP V-1 Bohunice as well as decomissioning of the NPP A-1 Bohunice. Other problems of the nuclear engineering were discussed. Totally, 201 participants from the Slovak Republic, Czech Republic and Germany and from other countries took part in the conference. The Conference included the following sessions: (i): Survey on the situation of nuclear power in the partner countries; (ii) Mochovce design safety enhacement and operational experience; (iii) Bohunice V-1 safety upgrading and operational experience; (iv) Decomissioning, spent fuel and radwaste management; (v) Young Generation Presentation. Proceedings contains thirty one papers dealing with the scope of INIS

  6. 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

  7. Molecular Evolutionary Characterization of a V1R Subfamily Unique to Strepsirrhine Primates

    Science.gov (United States)

    Yoder, Anne D.; Chan, Lauren M.; dos Reis, Mario; Larsen, Peter A.; Campbell, C. Ryan; Rasoloarison, Rodin; Barrett, Meredith; Roos, Christian; Kappeler, Peter; Bielawski, Joseph; Yang, Ziheng

    2014-01-01

    Vomeronasal receptor genes have frequently been invoked as integral to the establishment and maintenance of species boundaries among mammals due to the elaborate one-to-one correspondence between semiochemical signals and neuronal sensory inputs. Here, we report the most extensive sample of vomeronasal receptor class 1 (V1R) sequences ever generated for a diverse yet phylogenetically coherent group of mammals, the tooth-combed primates (suborder Strepsirrhini). Phylogenetic analysis confirms our intensive sampling from a single V1R subfamily, apparently unique to the strepsirrhine primates. We designate this subfamily as V1Rstrep. The subfamily retains extensive repertoires of gene copies that descend from an ancestral gene duplication that appears to have occurred prior to the diversification of all lemuriform primates excluding the basal genus Daubentonia (the aye-aye). We refer to the descendent clades as V1Rstrep-α and V1Rstrep-β. Comparison of the two clades reveals different amino acid compositions corresponding to the predicted ligand-binding site and thus potentially to altered functional profiles between the two. In agreement with previous studies of the mouse lemur (genus, Microcebus), the majority of V1Rstrep gene copies appear to be intact and under strong positive selection, particularly within transmembrane regions. Finally, despite the surprisingly high number of gene copies identified in this study, it is nonetheless probable that V1R diversity remains underestimated in these nonmodel primates and that complete characterization will be limited until high-coverage assembled genomes are available. PMID:24398377

  8. Ciguatoxins Evoke Potent CGRP Release by Activation of Voltage-Gated Sodium Channel Subtypes NaV1.9, NaV1.7 and NaV1.1

    Directory of Open Access Journals (Sweden)

    Filip Touska

    2017-08-01

    Full Text Available Ciguatoxins (CTXs are marine toxins that cause ciguatera fish poisoning, a debilitating disease dominated by sensory and neurological disturbances that include cold allodynia and various painful symptoms as well as long-lasting pruritus. Although CTXs are known as the most potent mammalian sodium channel activator toxins, the etiology of many of its neurosensory symptoms remains unresolved. We recently described that local application of 1 nM Pacific Ciguatoxin-1 (P-CTX-1 into the skin of human subjects induces a long-lasting, painful axon reflex flare and that CTXs are particularly effective in releasing calcitonin-gene related peptide (CGRP from nerve terminals. In this study, we used mouse and rat skin preparations and enzyme-linked immunosorbent assays (ELISA to study the molecular mechanism by which P-CTX-1 induces CGRP release. We show that P-CTX-1 induces CGRP release more effectively in mouse as compared to rat skin, exhibiting EC50 concentrations in the low nanomolar range. P-CTX-1-induced CGRP release from skin is dependent on extracellular calcium and sodium, but independent from the activation of various thermosensory transient receptor potential (TRP ion channels. In contrast, lidocaine and tetrodotoxin (TTX reduce CGRP release by 53–75%, with the remaining fraction involving L-type and T-type voltage-gated calcium channels (VGCC. Using transgenic mice, we revealed that the TTX-resistant voltage-gated sodium channel (VGSC NaV1.9, but not NaV1.8 or NaV1.7 alone and the combined activation of the TTX-sensitive VGSC subtypes NaV1.7 and NaV1.1 carry the largest part of the P-CTX-1-caused CGRP release of 42% and 34%, respectively. Given the contribution of CGRP to nociceptive and itch sensing pathways, our findings contribute to a better understanding of sensory symptoms of acute and chronic ciguatera that may help in the identification of potential therapeutics.

  9. Ciguatoxins Evoke Potent CGRP Release by Activation of Voltage-Gated Sodium Channel Subtypes NaV1.9, NaV1.7 and NaV1.1

    Science.gov (United States)

    Touska, Filip; Sattler, Simon; Malsch, Philipp; Lewis, Richard J.; Zimmermann, Katharina

    2017-01-01

    Ciguatoxins (CTXs) are marine toxins that cause ciguatera fish poisoning, a debilitating disease dominated by sensory and neurological disturbances that include cold allodynia and various painful symptoms as well as long-lasting pruritus. Although CTXs are known as the most potent mammalian sodium channel activator toxins, the etiology of many of its neurosensory symptoms remains unresolved. We recently described that local application of 1 nM Pacific Ciguatoxin-1 (P-CTX-1) into the skin of human subjects induces a long-lasting, painful axon reflex flare and that CTXs are particularly effective in releasing calcitonin-gene related peptide (CGRP) from nerve terminals. In this study, we used mouse and rat skin preparations and enzyme-linked immunosorbent assays (ELISA) to study the molecular mechanism by which P-CTX-1 induces CGRP release. We show that P-CTX-1 induces CGRP release more effectively in mouse as compared to rat skin, exhibiting EC50 concentrations in the low nanomolar range. P-CTX-1-induced CGRP release from skin is dependent on extracellular calcium and sodium, but independent from the activation of various thermosensory transient receptor potential (TRP) ion channels. In contrast, lidocaine and tetrodotoxin (TTX) reduce CGRP release by 53–75%, with the remaining fraction involving L-type and T-type voltage-gated calcium channels (VGCC). Using transgenic mice, we revealed that the TTX-resistant voltage-gated sodium channel (VGSC) NaV1.9, but not NaV1.8 or NaV1.7 alone and the combined activation of the TTX-sensitive VGSC subtypes NaV1.7 and NaV1.1 carry the largest part of the P-CTX-1-caused CGRP release of 42% and 34%, respectively. Given the contribution of CGRP to nociceptive and itch sensing pathways, our findings contribute to a better understanding of sensory symptoms of acute and chronic ciguatera that may help in the identification of potential therapeutics. PMID:28867800

  10. Central vasopressin V1a receptors modulate neural processing in mothers facing intruder threat to pups

    OpenAIRE

    Caffrey, Martha K.; Nephew, Benjamin C.; Febo, Marcelo

    2009-01-01

    Vasopressin V1a receptors in the rat brain have been studied for their role in modulating aggression and anxiety. In the current study blood-oxygen-level-dependent (BOLD) functional MRI was used to test whether V1a receptors modulate neural processing in the maternal brain when dams are exposed to a male intruder. Primiparous females were given an intracerebroventricular (ICV) injection of vehicle or V1a receptor antagonist ([deamino-Pen1, O-Me-Try, Arg8]-Vasopressin, 125 ng/10 μL) 90-120 min...

  11. The Bet v 1 fold: an ancient, versatile scaffold for binding of large, hydrophobic ligands

    Directory of Open Access Journals (Sweden)

    Breiteneder Heimo

    2008-10-01

    Full Text Available Abstract Background The major birch pollen allergen, Bet v 1, is a member of the ubiquitous PR-10 family of plant pathogenesis-related proteins. In recent years, a number of diverse plant proteins with low sequence similarity to Bet v 1 was identified. In addition, determination of the Bet v 1 structure revealed the existence of a large superfamily of structurally related proteins. In this study, we aimed to identify and classify all Bet v 1-related structures from the Protein Data Bank and all Bet v 1-related sequences from the Uniprot database. Results Structural comparisons of representative members of already known protein families structurally related to Bet v 1 with all entries of the Protein Data Bank yielded 47 structures with non-identical sequences. They were classified into eleven families, five of which were newly identified and not included in the Structural Classification of Proteins database release 1.71. The taxonomic distribution of these families extracted from the Pfam protein family database showed that members of the polyketide cyclase family and the activator of Hsp90 ATPase homologue 1 family were distributed among all three superkingdoms, while members of some bacterial families were confined to a small number of species. Comparison of ligand binding activities of Bet v 1-like superfamily members revealed that their functions were related to binding and metabolism of large, hydrophobic compounds such as lipids, hormones, and antibiotics. Phylogenetic relationships within the Bet v 1 family, defined as the group of proteins with significant sequence similarity to Bet v 1, were determined by aligning 264 Bet v 1-related sequences. A distance-based phylogenetic tree yielded a classification into 11 subfamilies, nine exclusively containing plant sequences and two subfamilies of bacterial proteins. Plant sequences included the pathogenesis-related proteins 10, the major latex proteins/ripening-related proteins subfamily, and

  12. Proceedings of the 1. General Congress of Nuclear Energy. v. 1

    International Nuclear Information System (INIS)

    1986-01-01

    The proceedings of 1 General Congress of Nuclear Energy are presented. All fields related to nuclear energy are enclosed. In the first part the following fields are shown: safety analysis, science and technology of materials, nuclear materials, nuclear laws, education and trainning, reactor physics, nuclear physics, quality assurance, mathematical models, reactor operation, safeguards, advanced technologies, thermohydraulic and reactor licensing. (M.C.K.) [pt

  13. Cooperation of nuclear reactor controller ARM-5S and turbine TVER-02

    International Nuclear Information System (INIS)

    Wagner, K.; Lnenicka, B.; Pokorny, F.; Prochazka, F.

    1985-01-01

    Turbines of Czechoslovak make provided with controllers TVER-02 are installed in WWER-440 nuclear power plants under construction in Czechoslovakia. Reactor output is controlled using Soviet-made controllers ARM-5S which already comprise turbine controllers. The problems are analyzed of cooperation of both controllers, especially their parameters and transient processes in typical operating situations. The analysis uses the results of measurements performed during the power start-up of Unit 1 of the V-2 nuclear power plant at Jaslovske Bohunice. The results show that two types of control modes can be selected for the operation of the entire unit: the control to constant unit output, and control of unit output varying with turbine load selected on the TVER-02 controller or given by the demand of the power network. (Z.M.)

  14. Visual recognition memory, manifested as long-term habituation, requires synaptic plasticity in V1.

    Science.gov (United States)

    Cooke, Sam F; Komorowski, Robert W; Kaplan, Eitan S; Gavornik, Jeffrey P; Bear, Mark F

    2015-02-01

    Familiarity with stimuli that bring neither reward nor punishment, manifested through behavioral habituation, enables organisms to detect novelty and devote cognition to important elements of the environment. Here we describe in mice a form of long-term behavioral habituation to visual grating stimuli that is selective for stimulus orientation. Orientation-selective habituation (OSH) can be observed both in exploratory behavior in an open arena and in a stereotyped motor response to visual stimuli in head-restrained mice. We found that the latter behavioral response, termed a 'vidget', requires V1. Parallel electrophysiological recordings in V1 revealed that plasticity, in the form of stimulus-selective response potentiation (SRP), occurred in layer 4 of V1 as OSH developed. Local manipulations of V1 that prevented and reversed electrophysiological modifications likewise prevented and reversed memory demonstrated behaviorally. These findings suggest that a form of long-term visual recognition memory is stored via synaptic plasticity in primary sensory cortex.

  15. Draft Genome Sequences of Vibrio alginolyticus Strains V1 and V2, Opportunistic Marine Pathogens

    DEFF Research Database (Denmark)

    Castillo, Daniel; D'Alvise, Paul; Kalatzis, Panos G.

    2015-01-01

    We announce the draft genome sequences of Vibrio alginolyticus strains V1 and V2, isolated from juvenile Sparus aurata and Dentex dentex, respectively, during outbreaks of vibriosis. The genome sequences are 5,257,950 bp with a G+C content of 44.5% for V. alginolyticus V1 and 5,068,299 bp with a G...

  16. Proceedings of the 14th International Meeting NUSIM 2006. Joint Slovak, Czech and German Seminar on Nuclear Power

    International Nuclear Information System (INIS)

    2006-01-01

    During April 26-28, 2006 was carried out The 14 th Annual Nuclear Safety Information Meeting, NUSIM 2006. Scientific conference deals with problems of reactor safety upgrading, mainly of two blocks of the NPP V-1 Bohunice as well as decommissioning of the NPP A-1 Bohunice. Other problems of the nuclear engineering were discussed. The Conference proceeded in the following sessions: (I) Survey on the Situation of Nuclear Power in the Partner Countries; (II) Experiences with WWER operation. Almost 100 participants from the Slovak Republic, Austria, Serbia and Montenegro, Czech Republic and Germany took part in the conference. Thirty-three scientific lectures and three papers were presented.

  17. Characterization of V1R receptor (ora) genes in Lake Victoria cichlids.

    Science.gov (United States)

    Ota, Tomoki; Nikaido, Masato; Suzuki, Hikoyu; Hagino-Yamagishi, Kimiko; Okada, Norihiro

    2012-05-15

    Although olfaction could play a crucial role in underwater habitats by allowing fish to sense a variety of nonvolatile chemical signals, the importance of olfaction in species-rich cichlids is still controversial. In particular, examining whether cichlids rely on olfaction for reproduction is of primary interest to understand the mechanisms of speciation. In the present study, we explored the V1R (also known as ora) genes, which are believed to encode reproductive pheromone receptors in fish, in the genomes of Lake Victoria cichlids. By screening a bacterial artificial chromosome library, we identified all six intact V1R genes (V1R1 to V1R6) that have been reported in other teleost fish. Furthermore, RT-PCR and in situ hybridization analyses showed that all of the V1R genes were expressed in the olfactory epithelium, indicating that these receptors are functional in cichlids. These observations indicate that cichlids use V1R-mediated olfaction in some ways for their social behaviors. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Mixing of Chromatic and Luminance Retinal Signals in Primate Area V1.

    Science.gov (United States)

    Li, Xiaobing; Chen, Yao; Lashgari, Reza; Bereshpolova, Yulia; Swadlow, Harvey A; Lee, Barry B; Alonso, Jose Manuel

    2015-07-01

    Vision emerges from activation of chromatic and achromatic retinal channels whose interaction in visual cortex is still poorly understood. To investigate this interaction, we recorded neuronal activity from retinal ganglion cells and V1 cortical cells in macaques and measured their visual responses to grating stimuli that had either luminance contrast (luminance grating), chromatic contrast (chromatic grating), or a combination of the two (compound grating). As with parvocellular or koniocellular retinal ganglion cells, some V1 cells responded mostly to the chromatic contrast of the compound grating. As with magnocellular retinal ganglion cells, other V1 cells responded mostly to the luminance contrast and generated a frequency-doubled response to equiluminant chromatic gratings. Unlike magnocellular and parvocellular retinal ganglion cells, V1 cells formed a unimodal distribution for luminance/color preference with a 2- to 4-fold bias toward luminance. V1 cells associated with positive local field potentials in deep layers showed the strongest combined responses to color and luminance and, as a population, V1 cells encoded a diverse combination of luminance/color edges that matched edge distributions of natural scenes. Taken together, these results suggest that the primary visual cortex combines magnocellular and parvocellular retinal inputs to increase cortical receptive field diversity and to optimize visual processing of our natural environment. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  19. Single-molecule analysis of inhibitory pausing states of V1-ATPase.

    Science.gov (United States)

    Uner, Naciye Esma; Nishikawa, Yoshihiro; Okuno, Daichi; Nakano, Masahiro; Yokoyama, Ken; Noji, Hiroyuki

    2012-08-17

    V(1)-ATPase, the hydrophilic V-ATPase domain, is a rotary motor fueled by ATP hydrolysis. Here, we found that Thermus thermophilus V(1)-ATPase shows two types of inhibitory pauses interrupting continuous rotation: a short pause (SP, 4.2 s) that occurred frequently during rotation, and a long inhibitory pause (LP, >30 min) that terminated all active rotations. Both pauses occurred at the same angle for ATP binding and hydrolysis. Kinetic analysis revealed that the time constants of inactivation into and activation from the SP were too short to represent biochemically predicted ADP inhibition, suggesting that SP is a newly identified inhibitory state of V(1)-ATPase. The time constant of inactivation into LP was 17 min, consistent with one of the two time constants governing the inactivation process observed in bulk ATPase assay. When forcibly rotated in the forward direction, V(1) in LP resumed active rotation. Solution ADP suppressed the probability of mechanical activation, suggesting that mechanical rotation enhanced inhibitory ADP release. These features were highly consistent with mechanical activation of ADP-inhibited F(1), suggesting that LP represents the ADP-inhibited state of V(1)-ATPase. Mechanical activation largely depended on the direction and angular displacement of forced rotation, implying that V(1)-ATPase rotation modulates the off rate of ADP.

  20. 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...

  1. METEOR v1.0 - Design and structure of the software package; METEOR v1.0 - Estructura y modulos informaticos

    Energy Technology Data Exchange (ETDEWEB)

    Palomo, E.

    1994-07-01

    This script describes the structure and the separated modules of the software package METEOR for the statistical analysis of meteorological data series. It contains a systematic description of the subroutines of METEOR and, also, of the required shape for input and output files. The original version of METEOR have been developed by Ph.D. Elena Palomo, CIEMAT-IER, GIMASE. It is built by linking programs and routines written in FORTRAN 77 and it adds thc graphical capabilities of GNUPLOT. The shape of this toolbox was designed following the criteria of modularity, flexibility and agility criteria. All the input, output and analysis options are structured in three main menus: i) the first is aimed to evaluate the quality of the data set; ii) the second is aimed for pre-processing of the data; and iii) the third is aimed towards the statistical analyses and for creating the graphical outputs. Actually the information about METEOR is constituted by three documents written in spanish: 1) METEOR v1.0: User's guide; 2) METEOR v1.0: A usage example; 3) METEOR v 1.0: Design and structure of the software package. (Author)

  2. Regulation of Blood Pressure by Targeting CaV1.2-Galectin-1 Protein Interaction.

    Science.gov (United States)

    Hu, Zhenyu; Li, Guang; Wang, Jiong-Wei; Chong, Suet Yen; Yu, Dejie; Wang, Xiaoyuan; Soon, Jia Lin; Liang, Mui Cheng; Wong, Yuk Peng; Huang, Na; Colecraft, Henry M; Liao, Ping; Soong, Tuck Wah

    2018-04-12

    Background -L-type Ca V 1.2 channels play crucial roles in regulation of blood pressure. Galectin-1 (Gal-1), has been reported to bind to the I-II loop of Ca V 1.2 channels to reduce their current density. However, the mechanistic understanding for the down-regulation of Ca V 1.2 channels by Gal-1, and whether Gal-1 plays a direct role in blood pressure regulation remain unclear. Methods - In vitro experiments involving co-IP, western blot, patch-clamp recordings, immunohistochemistry and pressure myography were used to evaluate the molecular mechanisms by which Gal-1 down-regulates Ca V 1.2 channel in transfected HEK 293 cells, smooth muscle cells, arteries from Lgasl1 -/- mice, rat and human patients. In vivo experiments involving delivery of Tat-e9c peptide and AAV5-Gal-1 into rats were performed to investigate the effect of targeting Ca V 1.2-Gal-1 interaction on blood pressure monitored by tail cuff or telemetry methods. Results -Our study reveals that Gal-1 is a key regulator for proteasomal degradation of Ca V 1.2 channels. Gal-1 competed allosterically with Ca V β subunit for binding to the I-II loop of Ca V 1.2 channel. This competitive disruption of Ca V β binding led to Ca V 1.2 degradation by exposing the channels to poly-ubiquitination. Notably, we demonstrated that the inverse relationship of reduced Gal-1 and increased Ca V 1.2 protein levels in arteries was associated with hypertension in hypertensive rats and patients, and Gal-1 deficiency induces higher blood pressure in mice due to up-regulated Ca V 1.2 protein level in arteries. To directly regulate blood pressure by targeting the Ca V 1.2-Gal-1 interaction, we administered Tat-e9c, a peptide that competed for binding of Gal-1, by a mini-osmotic pump and this specific disruption of Ca V 1.2-Gal-1 coupling increased smooth muscle Ca V 1.2 currents, induced larger arterial contraction and caused hypertension in rats. In contrasting experiments, over-expression of Gal-1 in smooth muscle by a

  3. A Chimeric NaV1.8 Channel Expression System Based on HEK293T Cell Line

    Directory of Open Access Journals (Sweden)

    Xi Zhou

    2018-04-01

    Full Text Available Among the nine voltage-gated sodium channel (NaV subtypes, NaV1.8 is an attractive therapeutic target for pain. The heterologous expression of recombinant NaV1.8 currents is of particular importance for its electrophysiological and pharmacological studies. However, NaV1.8 expresses no or low-level functional currents when transiently transfected into non-neuronal cell lines. The present study aims to explore the molecular determinants limiting its functional expression and accordingly establish a functional NaV1.8 expression system. We conducted screening analysis of the NaV1.8 intracellular loops by constructing NaV chimeric channels and confirmed that the NaV1.8 C-terminus was the only limiting factor. Replacing this sequence with that of NaV1.4, NaV1.5, or NaV1.7 constructed functional channels (NaV1.8/1.4L5, NaV1.8/1.5L5, and NaV1.8/1.7L5, respectively, which expressed high-level NaV1.8-like currents in HEK293T cells. The chimeric channel NaV1.8/1.7L5 displayed much faster inactivation of its macroscopic currents than NaV1.8/1.4L5 and NaV1.8/1.5L5, and it was the most similar to wild-type NaV1.8 expressed in ND7/23 cells. Its currents were very stable during repetitive depolarizations, while its repriming kinetic was different from wild-type NaV1.8. Most importantly, NaV1.8/1.7L5 pharmacologically resembled wild-type NaV1.8 as revealed by testing their susceptibility to two NaV1.8 selective antagonists, APETx-2 and MrVIB. NaV chimeras study showed that at least the domain 2 and domain 4 of NaV1.8 were involved in binding with APETx-2. Our study provided new insights into the function of NaV1.8 intracellular loops, as well as a reliable and convenient expression system which could be useful in NaV1.8 studies.

  4. Figure-ground processing during fixational saccades in V1: indication for higher-order stability.

    Science.gov (United States)

    Gilad, Ariel; Pesoa, Yair; Ayzenshtat, Inbal; Slovin, Hamutal

    2014-02-26

    In a typical visual scene we continuously perceive a "figure" that is segregated from the surrounding "background" despite ongoing microsaccades and small saccades that are performed when attempting fixation (fixational saccades [FSs]). Previously reported neuronal correlates of figure-ground (FG) segregation in the primary visual cortex (V1) showed enhanced activity in the "figure" along with suppressed activity in the noisy "background." However, it is unknown how this FG modulation in V1 is affected by FSs. To investigate this question, we trained two monkeys to detect a contour embedded in a noisy background while simultaneously imaging V1 using voltage-sensitive dyes. During stimulus presentation, the monkeys typically performed 1-3 FSs, which displaced the contour over the retina. Using eye position and a 2D analytical model to map the stimulus onto V1, we were able to compute FG modulation before and after each FS. On the spatial cortical scale, we found that, after each FS, FG modulation follows the stimulus retinal displacement and "hops" within the V1 retinotopic map, suggesting visual instability. On the temporal scale, FG modulation is initiated in the new retinotopic position before it disappeared from the old retinotopic position. Moreover, the FG modulation developed faster after an FS, compared with after stimulus onset, which may contribute to visual stability of FG segregation, along the timeline of stimulus presentation. Therefore, despite spatial discontinuity of FG modulation in V1, the higher-order stability of FG modulation along time may enable our stable and continuous perception.

  5. Proceedings of the 13. annual conference of the Canadian Nuclear Society. V. 1

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-31

    Volume 1 of the proceedings of the 13. annual conference of the Canadian Nuclear Society includes sessions on the following topics: reactor physics, new concepts and technology, fuel behaviour, reactor design, safety analysis, fuel channel behaviour, equipment and design qualification. The individual papers have been abstracted separately.

  6. 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

  7. 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.

  8. 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.

  9. 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

  10. Optical, mechanical and TEM assessment of titania-doped Bi2V1 ...

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... Home; Journals; Bulletin of Materials Science; Volume 37; Issue 7. Optical, mechanical and TEM assessment of titania-doped Bi2V1−TiO5.5−δ bismuth vanadate oxides. Gurbinder Kaur Gary Pickrell Vishal Kumar Om Prakash Pandey Kulvir Singh Daniel Homa. Volume 37 Issue 7 December 2014 pp ...

  11. Visual recognition memory, manifest as long-term habituation, requires synaptic plasticity in V1

    Science.gov (United States)

    Cooke, Sam F.; Komorowski, Robert W.; Kaplan, Eitan S.; Gavornik, Jeffrey P.; Bear, Mark F.

    2015-01-01

    Familiarity with stimuli that bring neither reward nor punishment, manifested through behavioural habituation, enables organisms to detect novelty and devote cognition to important elements of the environment. Here we describe in mice a form of long-term behavioural habituation to visual grating stimuli that is selective for stimulus orientation. Orientation-selective habituation (OSH) can be observed both in exploratory behaviour in an open arena, and in a stereotyped motor response to visual stimuli in head-restrained mice. We show that the latter behavioural response, termed a vidget, requires V1. Parallel electrophysiological recordings in V1 reveal that plasticity, in the form of stimulus-selective response potentiation (SRP), occurs in layer 4 of V1 as OSH develops. Local manipulations of V1 that prevent and reverse electrophysiological modifications likewise prevent and reverse memory demonstrated behaviourally. These findings suggest that a form of long-term visual recognition memory is stored via synaptic plasticity in primary sensory cortex. PMID:25599221

  12. Combined sodium ion sensitivity in agonist binding and internalization of vasopressin V1b receptors.

    Science.gov (United States)

    Koshimizu, Taka-Aki; Kashiwazaki, Aki; Taniguchi, Junichi

    2016-05-03

    Reducing Na(+) in the extracellular environment may lead to two beneficial effects for increasing agonist binding to cell surface G-protein coupled receptors (GPCRs): reduction of Na(+)-mediated binding block and reduce of receptor internalization. However, such combined effects have not been explored. We used Chinese Hamster Ovary cells expressing vasopressin V1b receptors as a model to explore Na(+) sensitivity in agonist binding and receptor internalization. Under basal conditions, a large fraction of V1b receptors is located intracellularly, and a small fraction is in the plasma membrane. Decreases in external Na(+) increased cell surface [(3)H]AVP binding and decreased receptor internalization. Substitution of Na(+) by Cs(+) or NH4(+) inhibited agonist binding. To suppress receptor internalization, the concentration of NaCl, but not of CsCl, had to be less than 50 mM, due to the high sensitivity of the internalization machinery to Na(+) over Cs(+). Iso-osmotic supplementation of glucose or NH4Cl maintained internalization of the V1b receptor, even in a low-NaCl environment. Moreover, iodide ions, which acted as a counter anion, inhibited V1b agonist binding. In summary, we found external ionic conditions that could increase the presence of high-affinity state receptors at the cell surface with minimum internalization during agonist stimulations.

  13. Monitoring of primary circuit and reactor of NPP A-1

    International Nuclear Information System (INIS)

    Prazska, M.; Majersky, M.; Rezbarik, J.; Sekely, S.; Vozarik, P.; Walthery, R.; Stuller, P.

    2005-01-01

    Nuclear Power Plant A-1 in Jaslovske Bohunice was commissioned in 1972. Heavy water moderated, carbon dioxide cooled channel type reactor was shut down after two accidents in 1977. During more serious second accident, the reduced coolant flow caused local overheating of the fuel and consequent damage/melting of the fuel channel. Both accidents had led to the damage of several fuel assemblies with extensive local damage of fuel claddings. As a consequence, the main cooling circuit was significantly contaminated by fission products and long-life alpha nuclides. The detailed monitoring of dose rates, smearable contamination and sampling of contamination was performed. Extended monitoring in reacto vessel, primary circuit pipes, turbo-compressors, steam generators, main valves, gas tanks and also heavy water system with collectors, coolers, distilling and purification station, pumps and valves was done. Appropriate devices and procedures for the monitoring and examination of the installations were prepared and applied. Obtained results will serve for the future planning of the decontamination and decommissioning works. The 3-D model of the reactor that had been developed as part of this Project proved invaluable for orientation, visualisation, planning and analysis of results. Dose rates were measured in the technological channels from the reactor hall floor to the bottom of the hot gas chamber in decrements of 1 m and 0.5 m. The highest absolute values of dose rates were found in channels located in the middle of the reactor (up to 1900 mGy/h in the active zone region). It is estimated that the total contaminated area of primary circuit equipment (pipework, steam generators and turbo-compressors) is some 48 000 m 2 . It follows that the total gamma contamination is of the order of 10 14 to 10 15 Bq and total alpha contamination 10 11 to 10 13 Bq. The total amount of deposits in the gas circuit is about 14.3 tons. (authors)

  14. Chromatic detection from cone photoreceptors to V1 neurons to behavior in rhesus monkeys.

    Science.gov (United States)

    Hass, Charles A; Angueyra, Juan M; Lindbloom-Brown, Zachary; Rieke, Fred; Horwitz, Gregory D

    2015-01-01

    Chromatic sensitivity cannot exceed limits set by noise in the cone photoreceptors. To determine how close neurophysiological and psychophysical chromatic sensitivity come to these limits, we developed a parameter-free model of stimulus encoding in the cone outer segments, and we compared the sensitivity of the model to the psychophysical sensitivity of monkeys performing a detection task and to the sensitivity of individual V1 neurons. Modeled cones had a temporal impulse response and a noise power spectrum that were derived from in vitro recordings of macaque cones, and V1 recordings were made during performance of the detection task. The sensitivity of the simulated cone mosaic, the V1 neurons, and the monkeys were tightly yoked for low-spatiotemporal-frequency isoluminant modulations, indicating high-fidelity signal transmission for this class of stimuli. Under the conditions of our experiments and the assumptions for our model, the signal-to-noise ratio for these stimuli dropped by a factor of ∼3 between the cones and perception. Populations of weakly correlated V1 neurons narrowly exceeded the monkeys' chromatic sensitivity but fell well short of the cones' chromatic sensitivity, suggesting that most of the behavior-limiting noise lies between the cone outer segments and the output of V1. The sensitivity gap between the cones and behavior for achromatic stimuli was larger than for chromatic stimuli, indicating greater postreceptoral noise. The cone mosaic model provides a means to compare visual sensitivity across disparate stimuli and to identify sources of noise that limit visual sensitivity.

  15. Functional size of human visual area V1: a neural correlate of top-down attention.

    Science.gov (United States)

    Verghese, Ashika; Kolbe, Scott C; Anderson, Andrew J; Egan, Gary F; Vidyasagar, Trichur R

    2014-06-01

    Heavy demands are placed on the brain's attentional capacity when selecting a target item in a cluttered visual scene, or when reading. It is widely accepted that such attentional selection is mediated by top-down signals from higher cortical areas to early visual areas such as the primary visual cortex (V1). Further, it has also been reported that there is considerable variation in the surface area of V1. This variation may impact on either the number or specificity of attentional feedback signals and, thereby, the efficiency of attentional mechanisms. In this study, we investigated whether individual differences between humans performing attention-demanding tasks can be related to the functional area of V1. We found that those with a larger representation in V1 of the central 12° of the visual field as measured using BOLD signals from fMRI were able to perform a serial search task at a faster rate. In line with recent suggestions of the vital role of visuo-spatial attention in reading, the speed of reading showed a strong positive correlation with the speed of visual search, although it showed little correlation with the size of V1. The results support the idea that the functional size of the primary visual cortex is an important determinant of the efficiency of selective spatial attention for simple tasks, and that the attentional processing required for complex tasks like reading are to a large extent determined by other brain areas and inter-areal connections. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. 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

  17. 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

  18. 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.)

  19. 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.)

  20. Proceedings of the 4. General Congress on Nuclear Energy. v. 1

    International Nuclear Information System (INIS)

    1992-01-01

    The first volume of the 4. General Congress on Nuclear Energy presents works about transient and accident analysis; thermohydraulics; radioisotopes uses; fuel cycle; shield; material technology; nuclear installation construction and reactor and nuclear physics. (C.G.C.)

  1. 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

  2. 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

  3. International Conference Nuclear Energy in Central Europe 99, V. 1. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Gortnar, O; Stritar, A [Nuclear Society of Slovenia (Slovenia)

    1999-07-01

    International Conference Nuclear Energy in Central Europe is an annual meeting of the Nuclear Society of Slovenia. The proceedings contain 101 articles from Slovenia, surrounding countries and countries of the Central and Eastern European Region. Topics are: Reactor Physics, Research Reactors, Thermal Hydraulics, Structural Analysis, Probabilistic Safety Assessment, Severe Accidents, NPP Operation, Nuclear Energy and Public, Radioactive Waste, Radiological Protection and Environmental Issues, Nuclear Methods and Monte Carlo and Deterministic Transport Calculations.

  4. International Conference Nuclear Energy in Central Europe 99, V. 1. Proceedings

    International Nuclear Information System (INIS)

    Gortnar, O.; Stritar, A.

    1999-01-01

    International Conference Nuclear Energy in Central Europe is an annual meeting of the Nuclear Society of Slovenia. The proceedings contain 101 articles from Slovenia, surrounding countries and countries of the Central and Eastern European Region. Topics are: Reactor Physics, Research Reactors, Thermal Hydraulics, Structural Analysis, Probabilistic Safety Assessment, Severe Accidents, NPP Operation, Nuclear Energy and Public, Radioactive Waste, Radiological Protection and Environmental Issues, Nuclear Methods and Monte Carlo and Deterministic Transport Calculations

  5. 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.)

  6. Three-dimensional Force and Kinematic Interactions in V1 Skating at High Speeds.

    Science.gov (United States)

    Stöggl, Thomas; Holmberg, Hans-Christer

    2015-06-01

    To describe the detailed kinetics and kinematics associated with use of the V1 skating technique at high skiing speeds and to identify factors that predict performance. Fifteen elite male cross-country skiers performed an incremental roller-skiing speed test (Vpeak) on a treadmill using the V1 skating technique. Pole and plantar forces and whole-body kinematics were monitored at four submaximal speeds. The propulsive force of the "strong side" pole was greater than that of the "weak side" (P skating at high speeds. The faster skiers exhibit more symmetric leg motion on the "strong" and "weak" sides, as well as more synchronized poling. With respect to methods, the pressure insoles and three-dimensional kinematics in combination with the leg push-off model described here can easily be applied to all skating techniques, aiding in the evaluation of skiing techniques and comparison of effectiveness.

  7. Explosive Model Tarantula V1/JWL++ Calibration of LX-17: #2

    Energy Technology Data Exchange (ETDEWEB)

    Souers, P C; Vitello, P

    2009-05-01

    Tarantula V1 is a kinetic package for reactive flow codes that seeks to describe initiation, failure, dead zones and detonation simultaneously. The most important parameter is P1, the pressure between the initiation and failure regions. Both dead zone formation and failure can be largely controlled with this knob. However, V1 does failure with low settings and dead zones with higher settings, so that it cannot fulfill its purpose in the current format. To this end, V2 is under test. The derivation of the initiation threshold P0 is discussed. The derivation of the initiation pressure-tau curve as an output of Tarantula shows that the initiation package is sound. A desensitization package is also considered.

  8. Electronic, optical, and thermoelectric properties of Fe2+xV1−xAl

    Directory of Open Access Journals (Sweden)

    D. P. Rai

    2017-04-01

    Full Text Available We report the electronic, optical, and thermoelectric properties of full-Heusler alloy Fe2VAl with Fe antisite doping (Fe2+xV1−xAl as obtained from the first-principles Tran-Blaha modified Becke-Johnson potential. The results are discussed in relation to the available experimental data and show good agreements for the band gap, magnetic moment, and optical spectra. Exploring our transport data for thermoelectric applicability suggest that Fe2+xV1−xAl is a good candidate with a high figure of merit (ZT 0.75(0.65 for x = 0.25(0.50 at room temperature.

  9. MREG V1.1 : a multi-scale image registration algorithm for SAR applications.

    Energy Technology Data Exchange (ETDEWEB)

    Eichel, Paul H.

    2013-08-01

    MREG V1.1 is the sixth generation SAR image registration algorithm developed by the Signal Processing&Technology Department for Synthetic Aperture Radar applications. Like its predecessor algorithm REGI, it employs a powerful iterative multi-scale paradigm to achieve the competing goals of sub-pixel registration accuracy and the ability to handle large initial offsets. Since it is not model based, it allows for high fidelity tracking of spatially varying terrain-induced misregistration. Since it does not rely on image domain phase, it is equally adept at coherent and noncoherent image registration. This document provides a brief history of the registration processors developed by Dept. 5962 leading up to MREG V1.1, a full description of the signal processing steps involved in the algorithm, and a user's manual with application specific recommendations for CCD, TwoColor MultiView, and SAR stereoscopy.

  10. V1 spinal neurons regulate the speed of vertebrate locomotor outputs

    DEFF Research Database (Denmark)

    Gosgnach, Simon; Lanuza, Guillermo M.; Butt, Simon J B

    2006-01-01

    The neuronal networks that generate vertebrate movements such as walking and swimming are embedded in the spinal cord1-3. These networks, which are referred to as central pattern generators (CPGs), are ideal systems for determining how ensembles of neurons generate simple behavioural outputs...... for inhibition in regulating the frequency of the locomotor CPG rhythm, and also suggest that V1 neurons may have an evolutionarily conserved role in controlling the speed of vertebrate locomotor movements....

  11. Recurrent connectivity can account for the dynamics of disparity processing in V1

    Science.gov (United States)

    Samonds, Jason M.; Potetz, Brian R.; Tyler, Christopher W.; Lee, Tai Sing

    2013-01-01

    Disparity tuning measured in the primary visual cortex (V1) is described well by the disparity energy model, but not all aspects of disparity tuning are fully explained by the model. Such deviations from the disparity energy model provide us with insight into how network interactions may play a role in disparity processing and help to solve the stereo correspondence problem. Here, we propose a neuronal circuit model with recurrent connections that provides a simple account of the observed deviations. The model is based on recurrent connections inferred from neurophysiological observations on spike timing correlations, and is in good accord with existing data on disparity tuning dynamics. We further performed two additional experiments to test predictions of the model. First, we increased the size of stimuli to drive more neurons and provide a stronger recurrent input. Our model predicted sharper disparity tuning for larger stimuli. Second, we displayed anti-correlated stereograms, where dots of opposite luminance polarity are matched between the left- and right-eye images and result in inverted disparity tuning in the disparity energy model. In this case, our model predicted reduced sharpening and strength of inverted disparity tuning. For both experiments, the dynamics of disparity tuning observed from the neurophysiological recordings in macaque V1 matched model simulation predictions. Overall, the results of this study support the notion that, while the disparity energy model provides a primary account of disparity tuning in V1 neurons, neural disparity processing in V1 neurons is refined by recurrent interactions among elements in the neural circuit. PMID:23407952

  12. 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.)

  13. 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)

  14. 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

  15. A 'variable' stellar object in a variable blue nebula V-V 1-7

    International Nuclear Information System (INIS)

    Rao, N.K.; Gilra, D.P.

    1981-01-01

    V-V 1-7 is supposed to be one of the few planetary nebulae with Ao central stars and was included in the planetary-nebula catalogue as PK 235 + 1 0 1. The nebula was seen on the blue Palomar Observatory Sky Survey (POSS) print but not on the red print; as a result it was thought that it might be a reflection nebula. However, the symmetry of the nebula around the central star (HD 62001), and also the ultraviolet photometric variability of this central star led others to suggest that the nebula might be a nova shell. Subsequently it was found that the nebula V-V 1-7 has disappeared. It is not seen on any direct plate known to us except the POSS blue plate. In this paper the disappearance is reported (along with the nebula) of a stellar object, which appears within the 'nebular shell' of V-V 1-7 on the POSS blue plate, but not on the red plate. (author)

  16. Spatial Attention and Temporal Expectation Under Timed Uncertainty Predictably Modulate Neuronal Responses in Monkey V1

    Science.gov (United States)

    Sharma, Jitendra; Sugihara, Hiroki; Katz, Yarden; Schummers, James; Tenenbaum, Joshua; Sur, Mriganka

    2015-01-01

    The brain uses attention and expectation as flexible devices for optimizing behavioral responses associated with expected but unpredictably timed events. The neural bases of attention and expectation are thought to engage higher cognitive loci; however, their influence at the level of primary visual cortex (V1) remains unknown. Here, we asked whether single-neuron responses in monkey V1 were influenced by an attention task of unpredictable duration. Monkeys covertly attended to a spot that remained unchanged for a fixed period and then abruptly disappeared at variable times, prompting a lever release for reward. We show that monkeys responded progressively faster and performed better as the trial duration increased. Neural responses also followed monkey's task engagement—there was an early, but short duration, response facilitation, followed by a late but sustained increase during the time monkeys expected the attention spot to disappear. This late attentional modulation was significantly and negatively correlated with the reaction time and was well explained by a modified hazard function. Such bimodal, time-dependent changes were, however, absent in a task that did not require explicit attentional engagement. Thus, V1 neurons carry reliable signals of attention and temporal expectation that correlate with predictable influences on monkeys' behavioral responses. PMID:24836689

  17. Development and matching of binocular orientation preference in mouse V1.

    Science.gov (United States)

    Bhaumik, Basabi; Shah, Nishal P

    2014-01-01

    Eye-specific thalamic inputs converge in the primary visual cortex (V1) and form the basis of binocular vision. For normal binocular perceptions, such as depth and stereopsis, binocularly matched orientation preference between the two eyes is required. A critical period of binocular matching of orientation preference in mice during normal development is reported in literature. Using a reaction diffusion model we present the development of RF and orientation selectivity in mouse V1 and investigate the binocular orientation preference matching during the critical period. At the onset of the critical period the preferred orientations of the modeled cells are mostly mismatched in the two eyes and the mismatch decreases and reaches levels reported in juvenile mouse by the end of the critical period. At the end of critical period 39% of cells in binocular zone in our model cortex is orientation selective. In literature around 40% cortical cells are reported as orientation selective in mouse V1. The starting and the closing time for critical period determine the orientation preference alignment between the two eyes and orientation tuning in cortical cells. The absence of near neighbor interaction among cortical cells during the development of thalamo-cortical wiring causes a salt and pepper organization in the orientation preference map in mice. It also results in much lower % of orientation selective cells in mice as compared to ferrets and cats having organized orientation maps with pinwheels.

  18. Development and Matching of Binocular Orientation Preference in Mouse V1

    Directory of Open Access Journals (Sweden)

    Basabi eBhaumik

    2014-07-01

    Full Text Available Eye-specific thalamic inputs converge in the primary visual cortex (V1 and form the basis of binocular vision. For normal binocular perceptions, such as depth and stereopsis, binocularly matched orientation preference between the two eyes is required. A critical period of binocular matching of orientation preference in mice during normal development is reported in literature. Using a reaction diffusion model we present the development of RF and orientation selectivity in mouse V1 and investigate the binocular orientation preference matching during the critical period. At the onset of the critical period the preferred orientations of the modeled cells are mostly mismatched in the two eyes and the mismatch decreases and reaches levels reported in juvenile mouse by the end of the critical period. At the end of critical period 39% of cells in binocular zone in our model cortex is orientation selective. In literature around 40% cortical cells are reported as orientation selective in mouse V1. The starting and the closing time for critical period determine the orientation preference alignment between the two eyes and orientation tuning in cortical cells. The absence of near neighbor interaction among cortical cells during the development of thalmo-cortical wiring causes a salt and pepper organization in the orientation preference map in mice. It also results in much lower % of orientation selective cells in mice as compared to ferrets and cats having organized orientation maps with pinwheels.

  19. Revealing Detail along the Visual Hierarchy: Neural Clustering Preserves Acuity from V1 to V4.

    Science.gov (United States)

    Lu, Yiliang; Yin, Jiapeng; Chen, Zheyuan; Gong, Hongliang; Liu, Ye; Qian, Liling; Li, Xiaohong; Liu, Rui; Andolina, Ian Max; Wang, Wei

    2018-04-18

    How primates perceive objects along with their detailed features remains a mystery. This ability to make fine visual discriminations depends upon a high-acuity analysis of spatial frequency (SF) along the visual hierarchy from V1 to inferotemporal cortex. By studying the transformation of SF across macaque parafoveal V1, V2, and V4, we discovered SF-selective functional domains in V4 encoding higher SFs up to 12 cycles/°. These intermittent higher-SF-selective domains, surrounded by domains encoding lower SFs, violate the inverse relationship between SF preference and retinal eccentricity. The neural activities of higher- and lower-SF domains correspond to local and global features, respectively, of the same stimuli. Neural response latencies in high-SF domains are around 10 ms later than in low-SF domains, consistent with the coarse-to-fine nature of perception. Thus, our finding of preserved resolution from V1 into V4, separated both spatially and temporally, may serve as a connecting link for detailed object representation. Copyright © 2018 Elsevier Inc. All rights reserved.

  20. Contextual modulation revealed by optical imaging exhibits figural asymmetry in macaque V1 and V2.

    Science.gov (United States)

    Zarella, Mark D; Ts'o, Daniel Y

    2017-01-01

    Neurons in early visual cortical areas are influenced by stimuli presented well beyond the confines of their classical receptive fields, endowing them with the ability to encode fine-scale features while also having access to the global context of the visual scene. This property can potentially define a role for the early visual cortex to contribute to a number of important visual functions, such as surface segmentation and figure-ground segregation. It is unknown how extraclassical response properties conform to the functional architecture of the visual cortex, given the high degree of functional specialization in areas V1 and V2. We examined the spatial relationships of contextual activations in macaque V1 and V2 with intrinsic signal optical imaging. Using figure-ground stimulus configurations defined by orientation or motion, we found that extraclassical modulation is restricted to the cortical representations of the figural component of the stimulus. These modulations were positive in sign, suggesting a relative enhancement in neuronal activity that may reflect an excitatory influence. Orientation and motion cues produced similar patterns of activation that traversed the functional subdivisions of V2. The asymmetrical nature of the enhancement demonstrated the capacity for visual cortical areas as early as V1 to contribute to figure-ground segregation, and the results suggest that this information can be extracted from the population activity constrained only by retinotopy, and not the underlying functional organization.

  1. Cortical depth dependent population receptive field attraction by spatial attention in human V1.

    Science.gov (United States)

    Klein, Barrie P; Fracasso, Alessio; van Dijk, Jelle A; Paffen, Chris L E; Te Pas, Susan F; Dumoulin, Serge O

    2018-04-27

    Visual spatial attention concentrates neural resources at the attended location. Recently, we demonstrated that voluntary spatial attention attracts population receptive fields (pRFs) toward its location throughout the visual hierarchy. Theoretically, both a feed forward or feedback mechanism could underlie pRF attraction in a given cortical area. Here, we use sub-millimeter ultra-high field functional MRI to measure pRF attraction across cortical depth and assess the contribution of feed forward and feedback signals to pRF attraction. In line with previous findings, we find consistent attraction of pRFs with voluntary spatial attention in V1. When assessed as a function of cortical depth, we find pRF attraction in every cortical portion (deep, center and superficial), although the attraction is strongest in deep cortical portions (near the gray-white matter boundary). Following the organization of feed forward and feedback processing across V1, we speculate that a mixture of feed forward and feedback processing underlies pRF attraction in V1. Specifically, we propose that feedback processing contributes to the pRF attraction in deep cortical portions. Copyright © 2018. Published by Elsevier Inc.

  2. SModelS v1.1 user manual: Improving simplified model constraints with efficiency maps

    Science.gov (United States)

    Ambrogi, Federico; Kraml, Sabine; Kulkarni, Suchita; Laa, Ursula; Lessa, Andre; Magerl, Veronika; Sonneveld, Jory; Traub, Michael; Waltenberger, Wolfgang

    2018-06-01

    SModelS is an automatized tool for the interpretation of simplified model results from the LHC. It allows to decompose models of new physics obeying a Z2 symmetry into simplified model components, and to compare these against a large database of experimental results. The first release of SModelS, v1.0, used only cross section upper limit maps provided by the experimental collaborations. In this new release, v1.1, we extend the functionality of SModelS to efficiency maps. This increases the constraining power of the software, as efficiency maps allow to combine contributions to the same signal region from different simplified models. Other new features of version 1.1 include likelihood and χ2 calculations, extended information on the topology coverage, an extended database of experimental results as well as major speed upgrades for both the code and the database. We describe in detail the concepts and procedures used in SModelS v1.1, explaining in particular how upper limits and efficiency map results are dealt with in parallel. Detailed instructions for code usage are also provided.

  3. Purification and characterization of the V1 vasopressin receptor from rat liver

    International Nuclear Information System (INIS)

    Fishman, J.B.; Dickey, B.F.; Attisano, C.; Fine, R.E.

    1987-01-01

    The rat liver V1 vasopressin receptor was purified approximately 21,000-fold from rat liver microsomes. The receptor was solubilized from membranes using the zwitterionic detergent CHAPS (3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulfonate). Since the V1 receptor loses its ability to bind ligand when solubilized, the authors devised a liposome reconstitution system to assay vasopressin binding activity during purification. The purified receptor exhibits a K/sub d/ of 6 nm, when, prior to solubilization, the membranes were exposed to 1 μm vasopressin. This resulted in the association of a pertussis-toxin insensitive guanine-nucleotide binding protein with the receptor during most of the purification procedure. The authors are further characterizing the V1-associated G-proteins. In the absence of this association, the receptor has a K/sub d/ of 30 nM. Crosslinking of 125 I-vasopressin to a partially purified preparation of receptor demonstrated that the receptor had a molecular weight of approximately 68,000 under reducing conditions, and 58,000 under non-reducing conditions. The purification procedure may prove useful in purifying a number of small peptide hormone receptors (e.g., bradykinin, angiotensin II) and perhaps their associated G-proteins as well

  4. METEOR v1.0 - Design and structure of the software package

    International Nuclear Information System (INIS)

    Palomo, E.

    1994-01-01

    This script describes the structure and the separated modules of the software package METEOR for the statistical analysis of meteorological data series. It contains a systematic description of the subroutines of METEOR and, also, of the required shape for input and output files. The original version of METEOR have been developed by Ph.D. Elena Palomo, CIEMAT-IER, GIMASE. It is built by linking programs and routines written in FORTRAN 77 and it adds thc graphical capabilities of GNUPLOT. The shape of this toolbox was designed following the criteria of modularity, flexibility and agility criteria. All the input, output and analysis options are structured in three main menus: i) the first is aimed to evaluate the quality of the data set; ii) the second is aimed for pre-processing of the data; and iii) the third is aimed towards the statistical analyses and for creating the graphical outputs. Actually the information about METEOR is constituted by three documents written in spanish: 1) METEOR v1.0: User's guide; 2) METEOR v1.0: A usage example; 3) METEOR v 1.0: Design and structure of the software package. (Author)

  5. In vitro binding and receptor-mediated activity of terlipressin at vasopressin receptors V1 and V2.

    Science.gov (United States)

    Jamil, Khurram; Pappas, Stephen Chris; Devarakonda, Krishna R

    2018-01-01

    Terlipressin, a synthetic, systemic vasoconstrictor with selective activity at vasopressin-1 (V 1 ) receptors, is a pro-drug for the endogenous/natural porcine hormone [Lys 8 ]-vasopressin (LVP). We investigated binding and receptor-mediated cellular activities of terlipressin, LVP, and endogenous human hormone [Arg 8 ]-vasopressin (AVP) at V 1 and vasopressin-2 (V 2 ) receptors. Cell membrane homogenates of Chinese hamster ovary cells expressing human V 1 and V 2 receptors were used in competitive binding assays to measure receptor-binding activity. These cells were used in functional assays to measure receptor-mediated cellular activity of terlipressin, LVP, and AVP. Binding was measured by [ 3 H]AVP counts, and the activity was measured by fluorometric detection of intracellular calcium mobilization (V 1 ) and cyclic adenosine monophosphate (V 2 ). Binding potency at V 1 and V 2 was AVP>LVP>terlipressin. LVP and terlipressin had approximately sixfold higher affinity for V 1 than for V 2 . Cellular activity potency was also AVP>LVP>terlipressin. Terlipressin was a partial agonist at V 1 and a full agonist at V 2 ; LVP was a full agonist at both V 1 and V 2 . The in vivo response to terlipressin is likely due to the partial V 1 agonist activity of terlipressin and full V 1 agonist activity of its metabolite, LVP. These results provide supportive evidence for previous findings and further establish terlipressin pharmacology for vasopressin receptors.

  6. 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

  7. 76 FR 20835 - Amendment of VOR Federal Airways V-1, V-7, V-11 and V-20; Kona, HI

    Science.gov (United States)

    2011-04-14

    ...; Airspace Docket No. 10-AWP-20] Amendment of VOR Federal Airways V-1, V-7, V-11 and V-20; Kona, HI AGENCY..., HI; V-1, V-7, V-11 and V-20. The FAA is taking this action due to procedural changes requiring..., (76 FR 13082), amends VOR Federal Airways V-1, V-7 V-11 and V-20; Kona, HI. These VHF Omnidirectional...

  8. Tackling Bet v 1 and associated food allergies with a single hybrid protein.

    Science.gov (United States)

    Hofer, Heidi; Asam, Claudia; Hauser, Michael; Nagl, Birgit; Laimer, Josef; Himly, Martin; Briza, Peter; Ebner, Christof; Lang, Roland; Hawranek, Thomas; Bohle, Barbara; Lackner, Peter; Ferreira, Fátima; Wallner, Michael

    2017-08-01

    Allergy vaccines should be easily applicable, safe, and efficacious. For Bet v 1-mediated birch pollen and associated food allergies, a single wild-type allergen does not provide a complete solution. We aimed to combine immunologically relevant epitopes of Bet v 1 and the 2 clinically most important related food allergens from apple and hazelnut to a single hybrid protein, termed MBC4. After identification of T cell epitope-containing parts on each of the 3 parental allergens, the hybrid molecule was designed to cover relevant epitopes and evaluated in silico. Thereby a mutation was introduced into the hybrid sequence, which should alter the secondary structure without compromising the immunogenic properties of the molecule. MBC4 and the parental allergens were purified to homogeneity. Analyses of secondary structure elements revealed substantial changes rendering the hybrid de facto nonreactive with patients' serum IgE. Nevertheless, the protein was monomeric in solution. MBC4 was able to activate T-cell lines from donors with birch pollen allergy and from mice immunized with the parental allergens. Moreover, on immunization of mice and rabbits, MBC4 induced cross-reactive IgG antibodies, which were able to block the binding of human serum IgE. Directed epitope rearrangements combined with a knowledge-based structural modification resulted in a protein unable to bind IgE from allergic patients. Still, properties to activate specific T cells or induce blocking antibodies were conserved. This suggests that MBC4 is a suitable vaccine candidate for the simultaneous treatment of Bet v 1 and associated food allergies. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  9. Contextual modulation revealed by optical imaging exhibits figural asymmetry in macaque V1 and V2

    Directory of Open Access Journals (Sweden)

    Zarella MD

    2017-04-01

    Full Text Available Mark D Zarella, Daniel Y Ts’o Department of Neurosurgery, SUNY Upstate Medical University, Syracuse, NY, USA Abstract: Neurons in early visual cortical areas are influenced by stimuli presented well beyond the confines of their classical receptive fields, endowing them with the ability to encode fine-scale features while also having access to the global context of the visual scene. This property can potentially define a role for the early visual cortex to contribute to a number of important visual functions, such as surface segmentation and figure–ground segregation. It is unknown how extraclassical response properties conform to the functional architecture of the visual cortex, given the high degree of functional specialization in areas V1 and V2. We examined the spatial relationships of contextual activations in macaque V1 and V2 with intrinsic signal optical imaging. Using figure–ground stimulus configurations defined by orientation or motion, we found that extraclassical modulation is restricted to the cortical representations of the figural component of the stimulus. These modulations were positive in sign, suggesting a relative enhancement in neuronal activity that may reflect an excitatory influence. Orientation and motion cues produced similar patterns of activation that traversed the functional subdivisions of V2. The asymmetrical nature of the enhancement demonstrated the capacity for visual cortical areas as early as V1 to contribute to figure–ground segregation, and the results suggest that this information can be extracted from the population activity constrained only by retinotopy, and not the underlying functional organization. Keywords: striate, extrastriate, segmentation, figure–ground, functional organization

  10. Outbursting comet P/2010 V1 (Ikeya-Murakami): A miniature comet Holmes

    Energy Technology Data Exchange (ETDEWEB)

    Ishiguro, Masateru [Department of Physics and Astronomy, Seoul National University, Gwanak, Seoul 151-742 (Korea, Republic of); Jewitt, David [Department of Earth, Planetary and Space Sciences, University of California at Los Angeles, 595 Charles Young Drive East, Los Angeles, CA 90095-1567 (United States); Hanayama, Hidekazu; Miyaji, Takeshi; Fukushima, Hideo; Watanabe, Jun-ichi [Ishigakijima Astronomical Observatory, National Astronomical Observatory of Japan, Ishigaki, Okinawa 907-0024 (Japan); Usui, Fumihiko [Department of Astronomy, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Sekiguchi, Tomohiko [Department of Teacher Training, Hokkaido University of Education, 9 Hokumon, Asahikawa 070-8621 (Japan); Yanagisawa, Kenshi; Kuroda, Daisuke [Okayama Astrophysical Observatory, National Astronomical Observatory of Japan, Asaguchi, Okayama 719-0232 (Japan); Yoshida, Michitoshi [Hiroshima Astrophysical Science Center, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Ohta, Kouji [Department of Astronomy, Kyoto University, Kyoto 606-8502 (Japan); Kawai, Nobuyuki [Department of Physics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan)

    2014-05-20

    The short-period comet P/2010 V1 (Ikeya-Murakami, hereafter {sup V}1{sup )} was discovered visually by two amateur astronomers. The appearance of the comet was peculiar, consisting of an envelope, a spherical coma near the nucleus and a tail extending in the anti-solar direction. We investigated the brightness and the morphological development of the comet by taking optical images with ground-based telescopes. Our observations show that V1 experienced a large-scale explosion between UT 2010 October 31 and November 3. The color of the comet was consistent with the Sun (g' – R {sub C} = 0.61 ± 0.20, R {sub C} – I {sub C} = 0.20 ± 0.20, and B – R {sub C} = 0.93 ± 0.25), suggesting that dust particles were responsible for the brightening. We used a dynamical model to understand the peculiar morphology, and found that the envelope consisted of small grains (0.3-1 μm) expanding at a maximum speed of 500 ± 40 m s{sup –1}, while the tail and coma were composed of a wider range of dust particle sizes (0.4-570 μm) and expansion speeds 7-390 m s{sup –1}. The total mass of ejecta is ∼5 × 10{sup 8} kg and kinetic energy ∼5 × 10{sup 12} J. These values are much smaller than in the historic outburst of 17P/Holmes in 2007, but the energy per unit mass (1 × 10{sup 4} J kg{sup –1}) is comparable. The energy per unit mass is about 10% of the energy released during the crystallization of amorphous water ice suggesting that crystallization of buried amorphous ice can supply the mass and energy of the outburst ejecta.

  11. Serotonin Decreases the Gain of Visual Responses in Awake Macaque V1.

    Science.gov (United States)

    Seillier, Lenka; Lorenz, Corinna; Kawaguchi, Katsuhisa; Ott, Torben; Nieder, Andreas; Pourriahi, Paria; Nienborg, Hendrikje

    2017-11-22

    Serotonin, an important neuromodulator in the brain, is implicated in affective and cognitive functions. However, its role even for basic cortical processes is controversial. For example, in the mammalian primary visual cortex (V1), heterogenous serotonergic modulation has been observed in anesthetized animals. Here, we combined extracellular single-unit recordings with iontophoresis in awake animals. We examined the role of serotonin on well-defined tuning properties (orientation, spatial frequency, contrast, and size) in V1 of two male macaque monkeys. We find that in the awake macaque the modulatory effect of serotonin is surprisingly uniform: it causes a mainly multiplicative decrease of the visual responses and a slight increase in the stimulus-selective response latency. Moreover, serotonin neither systematically changes the selectivity or variability of the response, nor the interneuronal correlation unexplained by the stimulus ("noise-correlation"). The modulation by serotonin has qualitative similarities with that for a decrease in stimulus contrast, but differs quantitatively from decreasing contrast. It can be captured by a simple additive change to a threshold-linear spiking nonlinearity. Together, our results show that serotonin is well suited to control the response gain of neurons in V1 depending on the animal's behavioral or motivational context, complementing other known state-dependent gain-control mechanisms. SIGNIFICANCE STATEMENT Serotonin is an important neuromodulator in the brain and a major target for drugs used to treat psychiatric disorders. Nonetheless, surprisingly little is known about how it shapes information processing in sensory areas. Here we examined the serotonergic modulation of visual processing in the primary visual cortex of awake behaving macaque monkeys. We found that serotonin mainly decreased the gain of the visual responses, without systematically changing their selectivity, variability, or covariability. This

  12. 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.)

  13. 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

  14. 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

  15. 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

  16. Verification of the AZNHEX code v.1.4 with MCNP6 for different reference cases

    International Nuclear Information System (INIS)

    Galicia A, J.; Francois L, J. L.; Bastida O, G. E.; Del Valle G, E.

    2017-09-01

    The codes that make up the AZTLAN platform (AZTHECA, AZTRAN, AZKIND and AZNHEX) are currently in the testing phase simulating a variety of nuclear reactor assemblies and cores to compare and validate the results obtained for a particular case, with codes globally used in the nuclear area such as CASMO, Serpent and MCNP. The objective of this work is to continue improving the future versions of the codes of the AZTLAN platform so that accurate and reliable results can be obtained for the user. To test the current version of the AZNHEX code, 3 cases were taken into account, the first being the simulation of a VVER-440 reactor assembly; for the second case, the assembly of a fast reactor cooled with helium was simulated and for the third case it was decided to take up the case of the core of a fast reactor cooled with sodium, this because the previous versions of AZNHEX did not show adequate results and, in addition, they presented a considerable amount of limitations. The comparison and validation of the results (neutron multiplication factor, radial power, radial flow, axial power) for these three cases were made using the code MCNP6. The results obtained show that this version of AZNHEX produces values of the neutron multiplication factor and the neutron and power flow distributions very close to those of MCNP6. (Author)

  17. Concept of diagnostic monitoring of condition of selected equipment for V-1 nuclear power plant

    International Nuclear Information System (INIS)

    Jaros, I.

    1981-01-01

    The vibroacoustic method based on picking up and processing vibrations, shocks and structural noise from the outer surface of equipment was chosen for testing the mechanical conditions of the reactor and of the main circulating pumps. The location of vibration pickups on the primary circuit components, their specifications, signal processing and evaluation are described. (M.D.)

  18. 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

  19. Calculational experimental examination and ensuring of equipment and pipelines seismic resistance at starting and operating water-cooled and moderated reactor WWER-type NPPs. Final report

    International Nuclear Information System (INIS)

    1999-01-01

    The results of testing of equipment at Bohunice NPP and pipeline systems at Unit 3 of Kozloduy NPP (WWER-440 type reactors) are presented in this Final Report. These results side by side with experimental values of natural frequencies and decrements also include experimental data about vibration modes of tested equipment and pipelines. For the first time the results of new calculational-experimental examination of equipment seismic resistance at Unit 2 of Armenian NPP are presented. At Kozloduy NPP direction's request the planed additional tests of some selected items were put off on 1997. Instead of postponed tests we carried out detailed analysis of our past inspections of numerous equipment seismic resistance at the Unit 5 of Kozloduy NPP. Experimental data with results of additional analysis are presented

  20. Statistical analysis of the vibration loading of the reactor internals and fuel assemblies of reactor units type WWER-440 from deferent projects

    International Nuclear Information System (INIS)

    Ovcharov, O.; Pavelko, V.; Usanov, A.; Arkadov, G.; Dolgov, A.; Molchanov, V.; Anikeev, J.; Pljush, A.

    2006-01-01

    In this paper the following items have been presented: 1) Vibration noise instrument channels; 2) Vibration loading characteristics of control assemblies, internals and design peculiarities of internals of WWER-440 deferent projects; 3) Coolant flow rate through the reactor, reactor core, fuel assemblies and control assemblies for different projects WWER-440 and 4) Noise measurements of coolant speed per channel. The change of auto power spectrum density of absolute displacement detector signal for the last 12 years of SUS monitoring of the Kola NPP unit 2; the coherence functions groups between two SPND of the same level for the Kola NPP unit 1; the measured coolant flow rate at Paks NPP and the auto power spectrum density group of SPND signals from 11 neutron measuring channels of the Kola NPP unit 1 are given. The main factors of vibration loading of internals and fuel assemblies for Kola NPP units 1-4, Bohunice NPP units 1 and 2 and Novovoronezh NPP units 3 and 4 are also discussed

  1. VUJE experience with large scale projects and their applicability to the future of the Slovak energy system

    International Nuclear Information System (INIS)

    Ferenc, M.

    2004-01-01

    In this presentation author deals with participation of VUJE Trnava, Inc. on the reconstruction of the Bohunice V1 NPP, on modernisation of the Bohunice V2 NPP, and on of the projects in nuclear energy industry including of decommissioning of the Bohunice A1 NPP

  2. SHARP pre-release v1.0 - Current Status and Documentation

    Energy Technology Data Exchange (ETDEWEB)

    Mahadevan, Vijay S. [Argonne National Lab. (ANL), Argonne, IL (United States); Rahaman, Ronald O. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-09-30

    The NEAMS Reactor Product Line effort aims to develop an integrated multiphysics simulation capability for the design and analysis of future generations of nuclear power plants. The Reactor Product Line code suite’s multi-resolution hierarchy is being designed to ultimately span the full range of length and time scales present in relevant reactor design and safety analyses, as well as scale from desktop to petaflop computing platforms. In this report, building on a several previous report issued in September 2014, we describe our continued efforts to integrate thermal/hydraulics, neutronics, and structural mechanics modeling codes to perform coupled analysis of a representative fast sodium-cooled reactor core in preparation for a unified release of the toolkit. The work reported in the current document covers the software engineering aspects of managing the entire stack of components in the SHARP toolkit and the continuous integration efforts ongoing to prepare a release candidate for interested reactor analysis users. Here we report on the continued integration effort of PROTEUS/Nek5000 and Diablo into the NEAMS framework and the software processes that enable users to utilize the capabilities without losing scientific productivity. Due to the complexity of the individual modules and their necessary/optional dependency library chain, we focus on the configuration and build aspects for the SHARP toolkit, which includes capability to autodownload dependencies and configure/install with optimal flags in an architecture-aware fashion. Such complexity is untenable without strong software engineering processes such as source management, source control, change reviews, unit tests, integration tests and continuous test suites. Details on these processes are provided in the report as a building step for a SHARP user guide that will accompany the first release, expected by Mar 2016.

  3. Comparative severe accident analysis of WWER 1000/B 320 LOCA DN100 computed by computer codes ASTEC V1.1 and SCDAP/RELAP5

    International Nuclear Information System (INIS)

    Kalchev, B.; Dimov, D.; Tusheva, P.; Mladenov, I.

    2005-01-01

    This paper presents the modelling approach for LOCA 100 mm sequence for WWER 1000-B 320 type of reactor with the integral ASTEC computer code and SCDAP/RELAP5 computer code. As a basic input deck the reference input file for Balakovo NPP from the released ASTEC CD has been applied. As a first part of the calculations for the SBLOCA sequence the ASTEC v1.1 modules CESAR, DIVA and CPA have been activated in a coupled mode. For SCDAP/RELAP5 calculation input deck for WWER 1000-B 320 has been applied which meant to be closer to the initial boundary conditions applied for ASTEC WWER 1000 input deck. A SBLOCA 100 mm comparison between ASTEC v1.1 and SCADAP/RELAP5 has been presented. ASTEC predicts vessel failure at 15620 s. ASTEC and SCDAP/RELAP5 give close but not similar results - this could be observed on the trends. The comparison of 100 mm-break shows that SCDAP/RELAP5 predicts clear phenomenological changes in primary pressure evolution and molten pool formation. Similar hydrogen production mass for both codes around 5000 s is detected

  4. Effects of grain size on high temperature creep of fine grained, solution and dispersion hardened V-1.6Y-8W-0.8TiC

    Energy Technology Data Exchange (ETDEWEB)

    Furuno, T. [Ehime Univerisity, 3 Bunkyo-cho, Matsuyama 790-8577 (Japan); Kurishita, H., E-mail: kurishi@imr.tohoku.ac.jp [International Research Center for Nuclear Materials Science, Institute for Materials Research (IMR), Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Nagasaka, T.; Nishimura, A.; Muroga, T. [Fusion Engineering Research Center, National Institute for Fusion Science (NIFS), Oroshi-cho 322-6, Tok, Gifu 292 (Japan); Sakamoto, T.; Kobayashi, S.; Nakai, K. [Department of Materials Science and Biotechnology, Ehime Univerisity, 3 Bunkyo-cho, Matsuyama 790-8577 (Japan); Matsuo, S.; Arakawa, H. [International Research Center for Nuclear Materials Science, Institute for Materials Research (IMR), Tohoku University, Oarai, Ibaraki 311-1313 (Japan)

    2011-10-01

    Creep resistance is the major concern of vanadium and its alloys for fusion reactor structural applications. In order to elucidate the effects of grain size on the creep behavior of solution and dispersion strengthened vanadium alloys, V-1.6Y-8W-0.8TiC specimens with fine grain sizes from 0.58 to 1.45 {mu}m were prepared by mechanical alloying and HIP without any plastic working and tested at 1073 K and 250 MPa in vacuum. It is shown that the creep resistance of V-1.6Y-8W-0.8TiC depends strongly on grain size and increases with increasing grain size: The creep life for the grain size of 1.45 {mu}m is almost one order longer than that of 0.58 {mu}m, and about two orders longer than that of V-4Cr-4Ti (NIFS-Heat 2) although the grain size of V-4Cr-4Ti is as large as 17.8 {mu}m. The observed creep behavior is discussed in terms of grain size effects on dislocation glide and grain boundary sliding.

  5. Distinct roles of the cortical layers of area V1 in figure-ground segregation.

    Science.gov (United States)

    Self, Matthew W; van Kerkoerle, Timo; Supèr, Hans; Roelfsema, Pieter R

    2013-11-04

    What roles do the different cortical layers play in visual processing? We recorded simultaneously from all layers of the primary visual cortex while monkeys performed a figure-ground segregation task. This task can be divided into different subprocesses that are thought to engage feedforward, horizontal, and feedback processes at different time points. These different connection types have different patterns of laminar terminations in V1 and can therefore be distinguished with laminar recordings. We found that the visual response started 40 ms after stimulus presentation in layers 4 and 6, which are targets of feedforward connections from the lateral geniculate nucleus and distribute activity to the other layers. Boundary detection started shortly after the visual response. In this phase, boundaries of the figure induced synaptic currents and stronger neuronal responses in upper layer 4 and the superficial layers ~70 ms after stimulus onset, consistent with the hypothesis that they are detected by horizontal connections. In the next phase, ~30 ms later, synaptic inputs arrived in layers 1, 2, and 5 that receive feedback from higher visual areas, which caused the filling in of the representation of the entire figure with enhanced neuronal activity. The present results reveal unique contributions of the different cortical layers to the formation of a visual percept. This new blueprint of laminar processing may generalize to other tasks and to other areas of the cerebral cortex, where the layers are likely to have roles similar to those in area V1. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. FahamecV1:A Low Cost Automated Metaphase Detection System

    Directory of Open Access Journals (Sweden)

    H. Yilmaz

    2017-12-01

    Full Text Available In this study, FahamecV1 is introduced and investigated as a low cost and high accuracy solution for metaphase detection. Chromosome analysis is performed at the metaphase stage and high accuracy and automated detection of the metaphase stage plays an active role in decreasing analysis time. FahamecV1 includes an optic microscope, a motorized microscope stage, an electronic control unit, a camera, a computer and a software application. Printing components of the motorized microscope stage (using a 3D printer is of the main reasons for cost reduction. Operations such as stepper motor calibration, are detection, focusing, scanning, metaphase detection and saving of coordinates into a database are automatically performed. To detect metaphases, a filter named Metafilter is developed and applied. Average scanning time per preparate is 77 sec/cm2. True positive rate is calculated as 95.1%, true negative rate is calculated as 99.0% and accuracy is calculated as 98.8%.

  7. Differential calcium sensitivity in NaV 1.5 mixed syndrome mutants.

    Science.gov (United States)

    Abdelsayed, Mena; Baruteau, Alban-Elouen; Gibbs, Karen; Sanatani, Shubhayan; Krahn, Andrew D; Probst, Vincent; Ruben, Peter C

    2017-09-15

    SCN5a mutations may express gain-of-function (Long QT Syndrome-3), loss-of-function (Brugada Syndrome 1) or both (mixed syndromes), depending on the mutation and environmental triggers. One such trigger may be an increase in cytosolic calcium, accompanying exercise. Many mixed syndromes mutants, including ∆KPQ, E1784K, 1795insD and Q1909R, are found in calcium-sensitive regions. Elevated cytosolic calcium attenuates gain-of-function properties in ∆KPQ, 1795insD and Q1909R, but not in E1784K. By contrast, elevated cytosolic calcium further exacerbates gain-of-function in E1784K by destabilizing slow inactivation. Action potential modelling, using a modified O'Hara Rudy model, suggests that elevated heart rate rescues action potential duration in ∆KPQ, 1795insD and Q1909R, but not in E1784K. Action potential simulations suggest that E1784K carriers have an increased intracellular sodium-to-calcium ratio under bradycardia and tachycardia conditions. Elevated cytosolic calcium, which is common during high heart rates, ameliorates or exacerbates the mixed syndrome phenotype depending on the genetic signature. Inherited arrhythmias may arise from mutations in the gene for SCN5a, which encodes the cardiac voltage-gated sodium channel, Na V 1.5. Mutants in Na V 1.5 result in Brugada Syndrome (BrS1), Long-QT Syndrome (LQT3) or mixed syndromes (an overlap of BrS1/LQT3). Exercise is a potential arrhythmogenic trigger in mixed syndromes. We aimed to determine the effects of elevated cytosolic calcium, which is common during exercise, in mixed syndrome Na V 1.5 mutants. We used whole-cell patch clamp to assess the biophysical properties of Na V 1.5 wild-type (WT), ∆KPQ, E1784K, 1795insD and Q1909R mutants in human embryonic kidney 293 cells transiently transfected with the Na V 1.5 α subunit (WT or mutants), β1 subunit and enhanced green fluorescent protein. Voltage-dependence and kinetics were measured at cytosolic calcium levels of approximately 0, 500 and 2500

  8. Functional Na(V)1.8 Channels in Intracardiac Neurons The Link Between SCN10A and Cardiac Electrophysiology

    NARCIS (Netherlands)

    Verkerk, Arie O.; Remme, Carol Ann; Schumacher, Cees A.; Scicluna, Brendon P.; Wolswinkel, Rianne; de Jonge, Berend; Bezzina, Connie R.; Veldkamp, Marieke W.

    2012-01-01

    Rationale: The SCN10A gene encodes the neuronal sodium channel isoform Na(V)1.8. Several recent genome-wide association studies have linked SCN10A to PR interval and QRS duration, strongly suggesting an as-yet unknown role for Na(V)1.8 in cardiac electrophysiology. Objective: To demonstrate the

  9. Responsiveness of the major birch allergen Bet v 1 scaffold to the gastric environment: Impact on structure and allergenic activity

    DEFF Research Database (Denmark)

    Sancho, Ana I; Wangorsch, Andrea; Jensen, Bettina M

    2011-01-01

    Four Bet v 1 homologous food allergens from celeriac (rApi g 1), apple (rMal d 1), peach (rPru p 1) and hazelnut (rCor a 1), were used to probe the structural responsiveness of the Bet v 1 scaffold to gastric digestion conditions and its impact on allergenicity....

  10. Problems of WWER-440 dynamic changes

    International Nuclear Information System (INIS)

    Rydzi, S.

    1986-01-01

    The data processing capability of the DYNAMIKA program is presented and demonstrated for the calculation of coolant parameters and heat transfer variables of the WWER reactor in accident and transient modes of operation. An experimental outage is described of the TG 11 turbogenerator at the V-1 Jaslovske Bohunice nuclear power plant. The measured values were compared with values calculated using the DYNAMIKA program. The graphic representation makes it evident that the mathematical model comes very close to reality. (J.B.)

  11. 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.

  12. 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

  13. 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)

  14. 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.)

  15. 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

  16. 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

  17. 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.)

  18. 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.)

  19. 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.)

  20. 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

  1. Statistical evaluation of failures and repairs of the V-1 measuring and control system

    International Nuclear Information System (INIS)

    Laurinec, R.; Korec, J.; Mitosinka, J.; Zarnovican, V.

    1984-01-01

    A failure record card system was introduced for evaluating the reliability of the measurement and control equipment of the V-1 nuclear power plant. The SPU-800 microcomputer system is used for recording data on magnetic tape and their transmission to the central data processing department. The data are used for evaluating the reliability of components and circuits and a selection is made of the most failure-prone components, and the causes of failures are evaluated as are failure identification, repair and causes of outages. The system provides monthly, annual and total assessment data since the system was commissioned. The results of the statistical evaluation of failures are used for planning preventive maintenance and for determining optimal repair intervals. (E.S.)

  2. Optimize of Deuteron Current of 150 keV, 1 mA Neutron Generator

    International Nuclear Information System (INIS)

    Sri Sulamdari; Djasiman

    2003-01-01

    It has been characterized a 150 keV/1 mA Neutron Generator. It has been used some local components, except accelerator tube and vacuum system. To produce neutron, it has been used a deuterium gas bombarded into tritium target through reaction 3 H(d,n) 4 He. For preliminary experiment, we used the air as an ion source. The beam current of deuteron as a function of process parameters are presented in this paper. It's found that the optimum beam current of deuteron was 1000 μA, and this conditions was achieved at accelerations voltage 30 kV, extraction voltage 5 kV, guide voltage -11 kV and vacuum 10 -6 mbar. (author)

  3. Population responses in V1 encode different figures by response amplitude.

    Science.gov (United States)

    Gilad, Ariel; Slovin, Hamutal

    2015-04-22

    The visual system simultaneously segregates between several objects presented in a visual scene. The neural code for encoding different objects or figures is not well understood. To study this question, we trained two monkeys to discriminate whether two elongated bars are either separate, thus generating two different figures, or connected, thus generating a single figure. Using voltage-sensitive dyes, we imaged at high spatial and temporal resolution V1 population responses evoked by the two bars, while keeping their local attributes similar among the two conditions. In the separate condition, unlike the connected condition, the population response to one bar is enhanced, whereas the response to the other is simultaneously suppressed. The response to the background remained unchanged between the two conditions. This divergent pattern developed ∼200 ms poststimulus onset and could discriminate well between the separate and connected single trials. The stimulus separation saliency and behavioral report were highly correlated with the differential response to the bars. In addition, the proximity and/or the specific location of the connectors seemed to have only a weak effect on this late activity pattern, further supporting the involvement of top-down influences. Additional neural codes were less informative about the separate and connected conditions, with much less consistency and discriminability compared with a response amplitude code. We suggest that V1 is involved in the encoding of each figure by different neuronal response amplitude, which can mediate their segregation and perception. Copyright © 2015 the authors 0270-6474/15/356335-15$15.00/0.

  4. Cue combination encoding via contextual modulation of V1 and V2 neurons

    Directory of Open Access Journals (Sweden)

    Zarella MD

    2016-10-01

    Full Text Available Mark D Zarella, Daniel Y Ts’o Department of Neurosurgery, SUNY Upstate Medical University, Syracuse, NY, USA Abstract: Neurons in early visual cortical areas encode the local properties of a stimulus in a number of different feature dimensions such as color, orientation, and motion. It has been shown, however, that stimuli presented well beyond the confines of the classical receptive field can augment these responses in a way that emphasizes these local attributes within the greater context of the visual scene. This mechanism imparts global information to cells that are otherwise considered local feature detectors and can potentially serve as an important foundation for surface segmentation, texture representation, and figure–ground segregation. The role of early visual cortex toward these functions remains somewhat of an enigma, as it is unclear how surface segmentation cues are integrated from multiple feature dimensions. We examined the impact of orientation- and motion-defined surface segmentation cues in V1 and V2 neurons using a stimulus in which the two features are completely separable. We find that, although some cells are modulated in a cue-invariant manner, many cells are influenced by only one cue or the other. Furthermore, cells that are modulated by both cues tend to be more strongly affected when both cues are presented together than when presented individually. These results demonstrate two mechanisms by which cue combinations can enhance salience. We find that feature-specific populations are more frequently encountered in V1, while cue additivity is more prominent in V2. These results highlight how two strongly interconnected areas at different stages in the cortical hierarchy can potentially contribute to scene segmentation. Keywords: striate, extrastriate, extraclassical, texture, segmentation

  5. Adaptive behavior of neighboring neurons during adaptation-induced plasticity of orientation tuning in V1

    Directory of Open Access Journals (Sweden)

    Shumikhina Svetlana

    2009-12-01

    Full Text Available Abstract Background Sensory neurons display transient changes of their response properties following prolonged exposure to an appropriate stimulus (adaptation. In adult cat primary visual cortex, orientation-selective neurons shift their preferred orientation after being adapted to a non-preferred orientation. The direction of those shifts, towards (attractive or away (repulsive from the adapter depends mostly on adaptation duration. How the adaptive behavior of a neuron is related to that of its neighbors remains unclear. Results Here we show that in most cases (75%, cells shift their preferred orientation in the same direction as their neighbors. We also found that cells shifting preferred orientation differently from their neighbors (25% display three interesting properties: (i larger variance of absolute shift amplitude, (ii wider tuning bandwidth and (iii larger range of preferred orientations among the cluster of cells. Several response properties of V1 neurons depend on their location within the cortical orientation map. Our results suggest that recording sites with both attractive and repulsive shifts following adaptation may be located in close proximity to iso-orientation domain boundaries or pinwheel centers. Indeed, those regions have a more diverse orientation distribution of local inputs that could account for the three properties above. On the other hand, sites with all cells shifting their preferred orientation in the same direction could be located within iso-orientation domains. Conclusions Our results suggest that the direction and amplitude of orientation preference shifts in V1 depend on location within the orientation map. This anisotropy of adaptation-induced plasticity, comparable to that of the visual cortex itself, could have important implications for our understanding of visual adaptation at the psychophysical level.

  6. Cholinergic and serotonergic modulation of visual information processing in monkey V1.

    Science.gov (United States)

    Shimegi, Satoshi; Kimura, Akihiro; Sato, Akinori; Aoyama, Chisa; Mizuyama, Ryo; Tsunoda, Keisuke; Ueda, Fuyuki; Araki, Sera; Goya, Ryoma; Sato, Hiromichi

    2016-09-01

    The brain dynamically changes its input-output relationship depending on the behavioral state and context in order to optimize information processing. At the molecular level, cholinergic/monoaminergic transmitters have been extensively studied as key players for the state/context-dependent modulation of brain function. In this paper, we review how cortical visual information processing in the primary visual cortex (V1) of macaque monkey, which has a highly differentiated laminar structure, is optimized by serotonergic and cholinergic systems by examining anatomical and in vivo electrophysiological aspects to highlight their similarities and distinctions. We show that these two systems have a similar layer bias for axonal fiber innervation and receptor distribution. The common target sites are the geniculorecipient layers and geniculocortical fibers, where the appropriate gain control is established through a geniculocortical signal transformation. Both systems exert activity-dependent response gain control across layers, but in a manner consistent with the receptor subtype. The serotonergic receptors 5-HT1B and 5HT2A modulate the contrast-response curve in a manner consistent with bi-directional response gain control, where the sign (facilitation/suppression) is switched according to the firing rate and is complementary to the other. On the other hand, cholinergic nicotinic/muscarinic receptors exert mono-directional response gain control without a sign reversal. Nicotinic receptors increase the response magnitude in a multiplicative manner, while muscarinic receptors exert both suppressive and facilitative effects. We discuss the implications of the two neuromodulator systems in hierarchical visual signal processing in V1 on the basis of the developed laminar structure. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Integrate-and-fire vs Poisson models of LGN input to V1 cortex: noisier inputs reduce orientation selectivity.

    Science.gov (United States)

    Lin, I-Chun; Xing, Dajun; Shapley, Robert

    2012-12-01

    One of the reasons the visual cortex has attracted the interest of computational neuroscience is that it has well-defined inputs. The lateral geniculate nucleus (LGN) of the thalamus is the source of visual signals to the primary visual cortex (V1). Most large-scale cortical network models approximate the spike trains of LGN neurons as simple Poisson point processes. However, many studies have shown that neurons in the early visual pathway are capable of spiking with high temporal precision and their discharges are not Poisson-like. To gain an understanding of how response variability in the LGN influences the behavior of V1, we study response properties of model V1 neurons that receive purely feedforward inputs from LGN cells modeled either as noisy leaky integrate-and-fire (NLIF) neurons or as inhomogeneous Poisson processes. We first demonstrate that the NLIF model is capable of reproducing many experimentally observed statistical properties of LGN neurons. Then we show that a V1 model in which the LGN input to a V1 neuron is modeled as a group of NLIF neurons produces higher orientation selectivity than the one with Poisson LGN input. The second result implies that statistical characteristics of LGN spike trains are important for V1's function. We conclude that physiologically motivated models of V1 need to include more realistic LGN spike trains that are less noisy than inhomogeneous Poisson processes.

  8. 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.)

  9. 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.)

  10. 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

  11. Pharmacological characterisation of the highly NaV1.7 selective spider venom peptide Pn3a

    OpenAIRE

    Deuis, J. R.; Dekan, Z.; Wingerd, J. S.; Smith, J. J.; Munasinghe, N. R.; Bhola, R. F.; Imlach, W. L.; Herzig, V.; Armstrong, D. A.; Rosengren, K. J.; Bosmans, F.; Waxman, S. G.; Dib-Hajj, S. D.; Escoubas, P.; Minett, M. S.

    2017-01-01

    Human genetic studies have implicated the voltage-gated sodium channel NaV1.7 as a therapeutic target for the treatment of pain. A novel peptide, μ-theraphotoxin-Pn3a, isolated from venom of the tarantula Pamphobeteus nigricolor, potently inhibits NaV1.7 (IC50 0.9 nM) with at least 40-1000-fold selectivity over all other NaV subtypes. Despite on-target activity in small-diameter dorsal root ganglia, spinal slices, and in a mouse model of pain induced by NaV1.7 activation, Pn3a alone displayed...

  12. Pharmacological characterisation of the highly NaV1.7 selective spider venom peptide Pn3a

    OpenAIRE

    Jennifer R. Deuis; Zoltan Dekan; Joshua S. Wingerd; Jennifer J. Smith; Nehan R. Munasinghe; Rebecca F. Bhola; Wendy L. Imlach; Volker Herzig; David A. Armstrong; K. Johan Rosengren; Frank Bosmans; Stephen G. Waxman; Sulayman D. Dib-Hajj; Pierre Escoubas; Michael S. Minett

    2017-01-01

    Human genetic studies have implicated the voltage-gated sodium channel NaV1.7 as a therapeutic target for the treatment of pain. A novel peptide, ?-theraphotoxin-Pn3a, isolated from venom of the tarantula Pamphobeteus nigricolor, potently inhibits NaV1.7 (IC50 0.9?nM) with at least 40?1000-fold selectivity over all other NaV subtypes. Despite on-target activity in small-diameter dorsal root ganglia, spinal slices, and in a mouse model of pain induced by NaV1.7 activation, Pn3a alone displayed...

  13. Proceedings of the third international conference on containment design and operation. v.1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    The second international conference on containment design and operation included sessions on the following topics: performance and regulatory requirements; radionuclide behaviour; severe accident design and analysis; operation, maintenance, leaking and aging of containment systems; thermal hydraulic behaviour of containment systems; hydrogen mixing and mitigation; design methods and concepts; code validation; structural analysis and response tests; passive safety systems; aerosol behaviour; containment reliability, integrity, and risk assessment; hydrogen deflagration and detonation. Due prominence was given to CANDU and other PHWR reactors. The individual papers have been abstracted separately.

  14. Proceedings of the third international conference on containment design and operation. v.1

    International Nuclear Information System (INIS)

    1994-01-01

    The second international conference on containment design and operation included sessions on the following topics: performance and regulatory requirements; radionuclide behaviour; severe accident design and analysis; operation, maintenance, leaking and aging of containment systems; thermal hydraulic behaviour of containment systems; hydrogen mixing and mitigation; design methods and concepts; code validation; structural analysis and response tests; passive safety systems; aerosol behaviour; containment reliability, integrity, and risk assessment; hydrogen deflagration and detonation. Due prominence was given to CANDU and other PHWR reactors. The individual papers have been abstracted separately

  15. 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

  16. 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.)

  17. 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.)

  18. 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.

  19. 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.

  20. BADGER v1.0: A Fortran equation of state library

    Science.gov (United States)

    Heltemes, T. A.; Moses, G. A.

    2012-12-01

    The BADGER equation of state library was developed to enable inertial confinement fusion plasma codes to more accurately model plasmas in the high-density, low-temperature regime. The code had the capability to calculate 1- and 2-T plasmas using the Thomas-Fermi model and an individual electron accounting model. Ion equation of state data can be calculated using an ideal gas model or via a quotidian equation of state with scaled binding energies. Electron equation of state data can be calculated via the ideal gas model or with an adaptation of the screened hydrogenic model with ℓ-splitting. The ionization and equation of state calculations can be done in local thermodynamic equilibrium or in a non-LTE mode using a variant of the Busquet equivalent temperature method. The code was written as a stand-alone Fortran library for ease of implementation by external codes. EOS results for aluminum are presented that show good agreement with the SESAME library and ionization calculations show good agreement with the FLYCHK code. Program summaryProgram title: BADGERLIB v1.0 Catalogue identifier: AEND_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEND_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 41 480 No. of bytes in distributed program, including test data, etc.: 2 904 451 Distribution format: tar.gz Programming language: Fortran 90. Computer: 32- or 64-bit PC, or Mac. Operating system: Windows, Linux, MacOS X. RAM: 249.496 kB plus 195.630 kB per isotope record in memory Classification: 19.1, 19.7. Nature of problem: Equation of State (EOS) calculations are necessary for the accurate simulation of high energy density plasmas. Historically, most EOS codes used in these simulations have relied on an ideal gas model. This model is inadequate for low

  1. 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

  2. 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

  3. 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.)

  4. Evaluation of the I. Stage of decommissioning and implementation of the II. Stage of decommissioning of NPP V1

    International Nuclear Information System (INIS)

    Hrasnova, E.

    2015-01-01

    In this paper author deals with following aspects: 1. Introduction of company Nuclear and Decommissioning Company, plc; 2. Evaluation of the I. stage of decommissioning and implementation of the II. Stage of decommissioning of NPP V1; (author)

  5. Simulations of corrosion product transfer with the OSCAR V1.2 code

    International Nuclear Information System (INIS)

    Dacquait, F.; Francescatto, J.; Broutin, F.; Genin, J.B.; Benier, G.; Girard, M.; You, D.; Ranchoux, G.; Bonnefon, J.; Bachet, M.; Riot, G.

    2012-09-01

    Activated Corrosion Products (ACPs) generate a radiation field in PWRs, which is the major contributor to the dose absorbed by nuclear power plant staff working during shutdown operations and maintenance. Therefore, a thorough understanding of the mechanisms that control the corrosion product transfer is of the highest importance. Since the 1970's, the R and D strategy in France has been based on experiments in test loops representative of PWR conditions, on in-situ gamma spectrometry measurements of the PWR primary system contamination and on simulation code development. The simulation of corrosion product transfers in PWR primary circuits is a major challenge since it involves many physical and chemical phenomena including: corrosion, dissolution, precipitation, erosion, deposition, convection, activation... In addition to the intrinsic difficulty of multi-physics modelling, the primary systems present severe operating conditions (300 deg. C, 150 bar, neutron flux, fluid velocity up to 15 m.s -1 and very low corrosion product concentrations). The purpose of the OSCAR code, developed by the CEA in cooperation with EDF and AREVA NP, is to predict the PWR primary system contamination by corrosion and fission products. The OSCAR code is considered to be not only a tool for numerical simulations and predictions (operational practices improvements and new-built PWRs design) but also one that might combine and organise all new knowledge useful to progress on contamination. The OSCAR code for Products of Corrosion, OSCAR PC, allows researchers to analyse the corrosion product behaviour and to calculate the ACP volume and surface activities of the primary and auxiliary systems. In the new version, OSCAR PC V1.2, the corrosion product transfer in the particulate form is enhanced and a new feature is the possibility to simulate cold shutdowns. In order to validate this version, the contamination transfer has been simulated in 5 French PWRs with different operating and

  6. 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.)

  7. 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.)

  8. Pharmacological characterisation of the highly NaV1.7 selective spider venom peptide Pn3a.

    Science.gov (United States)

    Deuis, Jennifer R; Dekan, Zoltan; Wingerd, Joshua S; Smith, Jennifer J; Munasinghe, Nehan R; Bhola, Rebecca F; Imlach, Wendy L; Herzig, Volker; Armstrong, David A; Rosengren, K Johan; Bosmans, Frank; Waxman, Stephen G; Dib-Hajj, Sulayman D; Escoubas, Pierre; Minett, Michael S; Christie, Macdonald J; King, Glenn F; Alewood, Paul F; Lewis, Richard J; Wood, John N; Vetter, Irina

    2017-01-20

    Human genetic studies have implicated the voltage-gated sodium channel Na V 1.7 as a therapeutic target for the treatment of pain. A novel peptide, μ-theraphotoxin-Pn3a, isolated from venom of the tarantula Pamphobeteus nigricolor, potently inhibits Na V 1.7 (IC 50 0.9 nM) with at least 40-1000-fold selectivity over all other Na V subtypes. Despite on-target activity in small-diameter dorsal root ganglia, spinal slices, and in a mouse model of pain induced by Na V 1.7 activation, Pn3a alone displayed no analgesic activity in formalin-, carrageenan- or FCA-induced pain in rodents when administered systemically. A broad lack of analgesic activity was also found for the selective Na V 1.7 inhibitors PF-04856264 and phlotoxin 1. However, when administered with subtherapeutic doses of opioids or the enkephalinase inhibitor thiorphan, these subtype-selective Na V 1.7 inhibitors produced profound analgesia. Our results suggest that in these inflammatory models, acute administration of peripherally restricted Na V 1.7 inhibitors can only produce analgesia when administered in combination with an opioid.

  9. Chemical modification of Art v 1, a major mugwort pollen allergen, by cis-aconitylation and citraconylation

    Directory of Open Access Journals (Sweden)

    DRAGANA STANIĆ

    2009-04-01

    Full Text Available Art v 1 is the major allergen of mugwort (Artemisia vulgaris pollen, a significant cause of hay fever all over Europe. Specific immunotherapy is the only treatment modality for allergic disease. Application of modified allergens makes the treatment safer and more efficient. In this work, two out of three (citraconic anhydride, cis-aconitic anhydride, 2,3-dimethylmaleic anhydride tested anhydrides were proven to be suitable for chemical modifications of allergens. Art v 1 was modified by cis-aconitylation and citraconylation in order to obtain derivatives of Art v 1 that may be suitable for further immunological testing. Acylation of Art v 1 gave derivatives (caaArt v 1 and citArt v 1 with about 80 % modified amino groups. The derivatives were in the monomeric form and had dramatically reduced pI values. Both derivatives were relatively stable at neutral pH values, while the acyl groups undergo hydrolysis under acidic conditions. Modification of allergens by cis-aconitylation and citraconylation could be a new tool for obtaining allergoids.

  10. Double-push skating versus V2 and V1 skating on uphill terrain in cross-country skiing.

    Science.gov (United States)

    Stöggl, Thomas; Kampel, Wolfgang; Müller, Erich; Lindinger, Stefan

    2010-01-01

    The aims of the study were a) to compare the double-push skating technique with the V2 and the V1 skating techniques on an uphill terrain by a kinematic and kinetic analysis, b) to provide kinetic and kinematic data of the V1 technique at maximal skiing speeds, and c) to test the hypotheses that the double-push skating technique is faster compared with the V2 and the V1 skating techniques. Six elite skiers performed maximum speed sprints over a 60-m uphill section (7 degrees -10 degrees) using the double-push, the V2, and the V1 techniques. Pole and plantar forces and cycle characteristics were analyzed. The double-push skating technique was approximately 4.3% faster (P push and the V2 techniques demonstrated longer cycle lengths, lower cycle rates (both P push technique compared with the V2 technique (all P values push technique compared with the other two techniques (P push techniques compared with the V2 technique stress the mechanical advantage of those techniques on uphill terrain. Because of larger cycle lengths, lower cycle rate, longer recovery times, and equal poling frequency, the double-push technique might be seen as more economic on steep uphills compared with the V1 technique. From a tactical point of view compared with the V1 technique, the double-push technique needs less space due to less lateral displacement, and no technique transitions are necessary when entering and leaving an uphill section.

  11. Contrast normalization contributes to a biologically-plausible model of receptive-field development in primary visual cortex (V1)

    Science.gov (United States)

    Willmore, Ben D.B.; Bulstrode, Harry; Tolhurst, David J.

    2012-01-01

    Neuronal populations in the primary visual cortex (V1) of mammals exhibit contrast normalization. Neurons that respond strongly to simple visual stimuli – such as sinusoidal gratings – respond less well to the same stimuli when they are presented as part of a more complex stimulus which also excites other, neighboring neurons. This phenomenon is generally attributed to generalized patterns of inhibitory connections between nearby V1 neurons. The Bienenstock, Cooper and Munro (BCM) rule is a neural network learning rule that, when trained on natural images, produces model neurons which, individually, have many tuning properties in common with real V1 neurons. However, when viewed as a population, a BCM network is very different from V1 – each member of the BCM population tends to respond to the same dominant features of visual input, producing an incomplete, highly redundant code for visual information. Here, we demonstrate that, by adding contrast normalization into the BCM rule, we arrive at a neurally-plausible Hebbian learning rule that can learn an efficient sparse, overcomplete representation that is a better model for stimulus selectivity in V1. This suggests that one role of contrast normalization in V1 is to guide the neonatal development of receptive fields, so that neurons respond to different features of visual input. PMID:22230381

  12. Anodal tDCS to V1 blocks visual perceptual learning consolidation.

    Science.gov (United States)

    Peters, Megan A K; Thompson, Benjamin; Merabet, Lotfi B; Wu, Allan D; Shams, Ladan

    2013-06-01

    This study examined the effects of visual cortex transcranial direct current stimulation (tDCS) on visual processing and learning. Participants performed a contrast detection task on two consecutive days. Each session consisted of a baseline measurement followed by measurements made during active or sham stimulation. On the first day, one group received anodal stimulation to primary visual cortex (V1), while another received cathodal stimulation. Stimulation polarity was reversed for these groups on the second day. The third (control) group of subjects received sham stimulation on both days. No improvements or decrements in contrast sensitivity relative to the same-day baseline were observed during real tDCS, nor was any within-session learning trend observed. However, task performance improved significantly from Day 1 to Day 2 for the participants who received cathodal tDCS on Day 1 and for the sham group. No such improvement was found for the participants who received anodal stimulation on Day 1, indicating that anodal tDCS blocked overnight consolidation of visual learning, perhaps through engagement of inhibitory homeostatic plasticity mechanisms or alteration of the signal-to-noise ratio within stimulated cortex. These results show that applying tDCS to the visual cortex can modify consolidation of visual learning. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Versican V1 Overexpression Induces a Myofibroblast-Like Phenotype in Cultured Fibroblasts.

    Directory of Open Access Journals (Sweden)

    Jon M Carthy

    Full Text Available Versican, a chondroitin sulphate proteoglycan, is one of the key components of the provisional extracellular matrix expressed after injury. The current study evaluated the hypothesis that a versican-rich matrix alters the phenotype of cultured fibroblasts.The full-length cDNA for the V1 isoform of human versican was cloned and the recombinant proteoglycan was expressed in murine fibroblasts. Versican expression induced a marked change in fibroblast phenotype. Functionally, the versican-expressing fibroblasts proliferated faster and displayed enhanced cell adhesion, but migrated slower than control cells. These changes in cell function were associated with greater N-cadherin and integrin β1 expression, along with increased FAK phosphorylation. The versican-expressing fibroblasts also displayed expression of smooth muscle α-actin, a marker of myofibroblast differentiation. Consistent with this observation, the versican fibroblasts displayed increased synthetic activity, as measured by collagen III mRNA expression, as well as a greater capacity to contract a collagen lattice. These changes appear to be mediated, at least in part, by an increase in active TGF-β signaling in the versican expressing fibroblasts, and this was measured by phosphorylation and nuclear accumulation of SMAD2.Collectively, these data indicate versican expression induces a myofibroblast-like phenotype in cultured fibroblasts.

  14. Crustal moment of inertia of glitching pulsars with the KDE0v1 Skyrme interaction

    Energy Technology Data Exchange (ETDEWEB)

    Madhuri, K.; Routray, T.R.; Pattnaik, S.P. [Sambalpur University, School of Physics, Jyotivihar (India); Basu, D.N. [Variable Energy Cyclotron Center, Kolkata (India)

    2017-07-15

    The mass, radius and crustal fraction of moment of inertia in neutron stars are calculated using β-equilibrated nuclear matter obtained from the Skyrme effective interaction. The transition density, pressure and proton fraction at the inner edge separating the liquid core from the solid crust of the neutron stars are determined from the thermodynamic stability conditions using the KDE0v1 set. The neutron star masses obtained by solving the Tolman-Oppenheimer-Volkoff equations using neutron star matter obtained from this set are able to describe highly massive compact stars ∝ 2M {sub CircleDot}. The crustal fraction of the moment of inertia can be extracted from studying pulsar glitches. This fraction is highly dependent on the core-crust transition pressure and corresponding density. These results for pressure and density at core-crust transition together with the observed minimum crustal fraction of the total moment of inertia provide a limit for the radius of the Vela pulsar, R ≥ 3.69 + 3.44M/M {sub CircleDot}. Present calculations suggest that the crustal fraction of the total moment of inertia can be ∝ 6.3% due to crustal entrainment caused by the Bragg reflection of unbound neutrons by lattice ions. (orig.)

  15. V1.42In1.83Mo15Se19

    Directory of Open Access Journals (Sweden)

    Michel Potel

    2010-10-01

    Full Text Available The structure of the title compound, vanadium indium pentadecamolybdenum nonadecaselenide, V1.42In1.83Mo15Se19, is isotypic with In2.9Mo15Se19 [Grüttner et al. (1979. Acta Cryst. B35, 285–292]. It is characterized by two cluster units Mo6Sei8Sea6 and Mo9Sei11Sea6 (where i represents inner and a apical atoms that are present in a 1:1 ratio. The cluster units are centered at Wyckoff positions 2b and 2c and have point-group symmetry overline{3} and overline{6}, respectively. The clusters are interconnected through additional Mo—Se bonds. In the title compound, the V3+ cations replace the trivalent indium atoms present in In2.9Mo15Se19, and a deficiency is observed on the monovalent indium site. One Mo, one Se and the V atom are situated on mirror planes, and two other Se atoms and the In atom are situated on threefold rotation axes.

  16. Synthesis and characterization of perovskites type La(Fe_xV_1_-_x)O_3

    International Nuclear Information System (INIS)

    Tupan, Lilian Felipe da Silva

    2014-01-01

    Perovskites of the La(Fe_xV_1_-_x)O_3 type were synthesized by solid state reaction and by arc-melting. The samples prepared were structurally characterized by X-ray diffraction and regarding the magnetic and hyperfine properties by "5"7Fe Mössbauer spectroscopy. The results revealed that the samples crystallized mostly with orthorhombic structure, in the Pbnm space group. The lattice parameters of the pseudo-ternary compounds decreased linearly with the progressive substitution of iron by vanadium, in agreement with the Vegard's law. It was also observed the reduction of the hyperfine magnetic field which changes from a well defined sextet of 51,8 T, obtained for LaFeO_3, to a magnetic field distribution and, further, to a paramagnetic component for the richest vanadium samples. Low temperature Mössbauer spectroscopy measurements were additionally performed for the La(Fe_0_,_2V_0_,_8)O_3 sample. It was shown that the sample recovers the magnetic order with decreasing temperature. These results reveal that the coexistence of iron-vanadium results in an even more complicated magnetic behavior, decreasing the magnetic transition temperature, as replacement of iron by vanadium in orthoferrite increases. (author)

  17. Perceptual Decision Making Through the Eyes of a Large-scale Neural Model of V1

    Directory of Open Access Journals (Sweden)

    Jianing eShi

    2013-04-01

    Full Text Available Sparse coding has been posited as an efficient information processing strategy employed by sensory systems, particularly visual cortex. Substantial theoretical and experimental work has focused on the issue of sparse encoding, namely how the early visual system maps the scene into a sparse representation. In this paper we investigate the complementary issue of sparse decoding, for example given activity generated by a realistic mapping of the visual scene to neuronal spike trains, how do downstream neurons best utilize this representation to generate a decision. Specifically we consider both sparse (L1 regularized and non-sparse (L2 regularized linear decoding for mapping the neural dynamics of a large-scale spiking neuron model of primary visual cortex (V1 to a two alternative forced choice (2-AFC perceptual decision. We show that while both sparse and non-sparse linear decoding yield discrimination results quantitatively consistent with human psychophysics, sparse linear decoding is more efficient in terms of the number of selected informative dimension.

  18. Correlations in V1 are reduced by stimulation outside the receptive field.

    Science.gov (United States)

    Snyder, Adam C; Morais, Michael J; Kohn, Adam; Smith, Matthew A

    2014-08-20

    The trial-to-trial response variability of nearby cortical neurons is correlated. These correlations may strongly influence population coding performance. Numerous studies have shown that correlations can be dynamically modified by attention, adaptation, learning, and potent stimulus drive. However, the mechanisms that influence correlation strength remain poorly understood. Here we test whether correlations are influenced by presenting stimuli outside the classical receptive field (RF) of visual neurons, where they recruit a normalization signal termed surround suppression. We recorded simultaneously the activity of dozens of cells using microelectrode arrays implanted in the superficial layers of V1 in anesthetized, paralyzed macaque monkeys. We presented annular stimuli that encircled--but did not impinge upon--the RFs of the recorded cells. We found that these "extra-classical" stimuli reduced correlations in the absence of stimulation of the RF, closely resembling the decorrelating effects of stimulating the RFs directly. Our results suggest that normalization signals may be an important mechanism for modulating correlations. Copyright © 2014 the authors 0270-6474/14/3411222-06$15.00/0.

  19. 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.)

  20. 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

  1. Validity and Reliability of Adult ADHD Self-Report Scale Thai Version (ASRS-V1.1 TH).

    Science.gov (United States)

    Kiatrungrit, Komsan; Putthisri, Suwannee; Hongsanguansri, Sirichai; Wisajan, Pattaraporn; Jullagate, Sudawan

    2017-08-25

    The adult ADHD Self-Report Scale Thai version (ASRS-V1.1) (18 items) is a questionnaire for screening adult ADHD. To test the validity and reliability of the 18-question ASRS-V1.1 Thai version (ASRS-V1.1 TH) as a screening tool for adult ADHD. The original 18-question ASRS-V1.1 version was translated into Thai. The process was composed of forward-translation, synthesis of the translation, and back translation. Cross cultural adaptation, field testing, and final adjustment were completed consecutively. The 18-question ASRS-V1.1 TH were sent to 1,500 parents of kindergarten and elementary school students in Bangkok, Thailand. The diagnostic interview was randomly selected for 50 parents from the positive result group and 50 parents from the negative result group. The clinical interview for confirming diagnosis was run by 3 psychiatrists who were blinded to the results and used DSM-5 ADHD criteria for diagnosis. The 18-question ASRS-V1.1 TH had satisfactory internal consistency (Cronbach's alpha = 0.92: Cronbach's alpha = 0.87 for inattentive scale, Cronbach's alpha = 0.84 for hyperactive / impulsive scale). For testing the criteria validity, the questionnaire has an adequate. The AUC from the first 6 questions was 0.80 (95% CI: 0.68-0.92) while from the 18 questions was 0.71(95% CI: 0.55-0.86). The 18-question ASRS-V1.1TH is a psychometrically reliable and valid measure for screening adult ADHD in Thai clinical samples, especially the first 6 questions of the questionnaire.

  2. Linking retinotopic fMRI mapping and anatomical probability maps of human occipital areas V1 and V2.

    Science.gov (United States)

    Wohlschläger, A M; Specht, K; Lie, C; Mohlberg, H; Wohlschläger, A; Bente, K; Pietrzyk, U; Stöcker, T; Zilles, K; Amunts, K; Fink, G R

    2005-05-15

    Using functional MRI, we characterized field sign maps of the occipital cortex and created three-dimensional maps of these areas. By averaging the individual maps into group maps, probability maps of functionally defined V1 or V2 were determined and compared to anatomical probability maps of Brodmann areas BA17 and BA18 derived from cytoarchitectonic analysis (Amunts, K., Malikovic, A., Mohlberg, H., Schormann, T., Zilles, K., 2000. Brodmann's areas 17 and 18 brought into stereotaxic space-where and how variable? NeuroImage 11, 66-84). Comparison of areas BA17/V1 and BA18/V2 revealed good agreement of the anatomical and functional probability maps. Taking into account that our functional stimulation (due to constraints of the visual angle of stimulation achievable in the MR scanner) only identified parts of V1 and V2, for statistical evaluation of the spatial correlation of V1 and BA17, or V2 and BA18, respectively, the a priori measure kappa was calculated testing the hypothesis that a region can only be part of functionally defined V1 or V2 if it is also in anatomically defined BA17 or BA18, respectively. kappa = 1 means the hypothesis is fully true, kappa = 0 means functionally and anatomically defined visual areas are independent. When applying this measure to the probability maps, kappa was equal to 0.84 for both V1/BA17 and V2/BA18. The data thus show a good correspondence of functionally and anatomically derived segregations of early visual processing areas and serve as a basis for employing anatomical probability maps of V1 and V2 in group analyses to characterize functional activations of early visual processing areas.

  3. Decomposition of BOLD Activity into Tuned and Untuned Components Reveals Cohabitation of Stimulus and Choice Information in V1

    Directory of Open Access Journals (Sweden)

    Kyoung Whan Choe

    2012-10-01

    Full Text Available Recent studies on V1 report top-down modulation of input-driven responses of sensory neurons, implying that exogenous sensory drives and endogenous top-down drives jointly determine V1 responses. By measuring fMRI responses in conjunction with a classification task on ambiguous ring stimuli, we sought to understand how V1 carries out its encoding operation on afferent currents while being adaptively modulated by top-down currents associated with perceptual tasks. Population activity of V1, as in its raw eccentricity profiles, failed to resolve the threshold differences between the ring stimuli due to large moment-to-moment fluctuations. The analysis of variance indicated that stimulus-evoked responses explain only one-fifth of the total variance and fMRI responses were highly correlated among eccentricity-bins, implying that a substantial fraction of V1 responses fluctuate as a whole. This led us to decompose the raw fMRI responses into untuned and tuned components: average response across eccentricity-bins and residual responses from the average, respectively, the former varying only in time and the latter varying in both space and time. The tuned responses revealed the veridical encoding operation of V1 by readily distinguishing between the ring stimuli, which was impossible with the raw fMRI responses. In contrast, the untuned were correlated with two major aspects of choice behavior—inter-trial variability in response time and inter-subject variability in response bias. We propose that this cohabitation of stimulus and choice information in V1 indicates the presence of top-down exertion of gain modulation on the early processing stage by the high-tier stage that accumulates evidence for perceptual choices.

  4. Phase Locking of Multiple Single Neurons to the Local Field Potential in Cat V1.

    Science.gov (United States)

    Martin, Kevan A C; Schröder, Sylvia

    2016-02-24

    The local field potential (LFP) is thought to reflect a temporal reference for neuronal spiking, which may facilitate information coding and orchestrate the communication between neural populations. To explore this proposed role, we recorded the LFP and simultaneously the spike activity of one to three nearby neurons in V1 of anesthetized cats during the presentation of drifting sinusoidal gratings, binary dense noise stimuli, and natural movies. In all stimulus conditions and during spontaneous activity, the average LFP power at frequencies >20 Hz was higher when neurons were spiking versus not spiking. The spikes were weakly but significantly phase locked to all frequencies of the LFP. The average spike phase of the LFP was stable across high and low levels of LFP power, but the strength of phase locking at low frequencies (≤10 Hz) increased with increasing LFP power. In a next step, we studied how strong stimulus responses of single neurons are reflected in the LFP and the LFP-spike relationship. We found that LFP power was slightly increased and phase locking was slightly stronger during strong compared with weak stimulus-locked responses. In summary, the coupling strength between high frequencies of the LFP and spikes was not strongly modulated by LFP power, which is thought to reflect spiking synchrony, nor was it strongly influenced by how strongly the neuron was driven by the stimulus. Furthermore, a comparison between neighboring neurons showed no clustering of preferred LFP phase. We argue that hypotheses on the relevance of phase locking in their current form are inconsistent with our findings. Copyright © 2016 the authors 0270-6474/16/362494-09$15.00/0.

  5. VizieR Online Data Catalog: Hubble Source Catalog (V1 and V2) (Whitmore+, 2016)

    Science.gov (United States)

    Whitmore, B. C.; Allam, S. S.; Budavari, T.; Casertano, S.; Downes, R. A.; Donaldson, T.; Fall, S. M.; Lubow, S. H.; Quick, L.; Strolger, L.-G.; Wallace, G.; White, R. L.

    2016-10-01

    The HSC v1 contains members of the WFPC2, ACS/WFC, WFC3/UVIS and WFC3/IR Source Extractor source lists from HLA version DR8 (data release 8). The crossmatching process involves adjusting the relative astrometry of overlapping images so as to minimize positional offsets between closely aligned sources in different images. After correction, the astrometric residuals of crossmatched sources are significantly reduced, to typically less than 10mas. The relative astrometry is supported by using Pan-STARRS, SDSS, and 2MASS as the astrometric backbone for initial corrections. In addition, the catalog includes source nondetections. The crossmatching algorithms and the properties of the initial (Beta 0.1) catalog are described in Budavari & Lubow (2012ApJ...761..188B). The HSC v2 contains members of the WFPC2, ACS/WFC, WFC3/UVIS and WFC3/IR Source Extractor source lists from HLA version DR9.1 (data release 9.1). The crossmatching process involves adjusting the relative astrometry of overlapping images so as to minimize positional offsets between closely aligned sources in different images. After correction, the astrometric residuals of crossmatched sources are significantly reduced, to typically less than 10mas. The relative astrometry is supported by using Pan-STARRS, SDSS, and 2MASS as the astrometric backbone for initial corrections. In addition, the catalog includes source nondetections. The crossmatching algorithms and the properties of the initial (Beta 0.1) catalog are described in Budavari & Lubow (2012ApJ...761..188B). Hubble Source Catalog Acknowledgement: Based on observations made with the NASA/ESA Hubble Space Telescope, and obtained from the Hubble Legacy Archive, which is a collaboration between the Space Telescope Science Institute (STScI/NASA), the Space Telescope European Coordinating Facility (ST-ECF/ESAC/ESA) and the Canadian Astronomy Data Centre (CADC/NRC/CSA). (2 data files).

  6. Application of the MASH v1.0 Code System to radiological warfare radiation threats

    International Nuclear Information System (INIS)

    Johnson, J.O.; Santoro, R.T.; Smith, M.S.

    1994-01-01

    Nuclear hardening capabilities of US and foreign ground force systems is a primary concern of the Department of Defense (DoD) and US Army. The Monte Carlo Adjoint Shielding Code System -- MASH v1.0 was developed at Oak Ridge National Laboratory (ORNL) to analyze these capabilities, i.e. the shielding effectiveness, for prompt radiation from a nuclear weapon detonation. Rapidly changing world events and the proliferation of nuclear weapons related technology have increased the kinds of nuclear threats to include intentionally dispersed radiation sources and fallout from tactical nuclear weapons used in the modern AirLand battlefield scenario. Consequently, a DoD area of increasing interest focuses on determining the shielding effectiveness of foreign and US armored vehicles to radiological warfare and fallout radiation threats. To demonstrate the applicability of MASH for analyzing dispersed radiation source problems, calculations have been completed for two distributed sources; a dispersed radiation environment simulated by a uniformly distributed 60 Co source, and a 235 U fission weapon fallout source. Fluence and dose assessments were performed for the free-field, the inside of a steel-walled two-meter box, in a phantom standing in the free-field, and in a phantom standing in the two-meter box. The results indicate substantial radiation protection factors for the 60 Co dispersed radiation source and the fallout source compared to the prompt radiation protection factors. The dose protection factors ranged from 40 to 95 for the two-meter box and from 55 to 123 for the mid-gut position of the phantom standing in the box. The results further indicate that a 60 Co source might be a good first order approximation for a tactical fission weapon fallout protection factor analysis

  7. 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.

  8. 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)

  9. 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.

  10. Simulation of reactivity-initiated accident transients on UO2-M5® fuel rods with ALCYONE V1.4 fuel performance code

    Directory of Open Access Journals (Sweden)

    Isabelle Guénot-Delahaie

    2018-03-01

    Full Text Available The ALCYONE multidimensional fuel performance code codeveloped by the CEA, EDF, and AREVA NP within the PLEIADES software environment models the behavior of fuel rods during irradiation in commercial pressurized water reactors (PWRs, power ramps in experimental reactors, or accidental conditions such as loss of coolant accidents or reactivity-initiated accidents (RIAs. As regards the latter case of transient in particular, ALCYONE is intended to predictively simulate the response of a fuel rod by taking account of mechanisms in a way that models the physics as closely as possible, encompassing all possible stages of the transient as well as various fuel/cladding material types and irradiation conditions of interest. On the way to complying with these objectives, ALCYONE development and validation shall include tests on PWR-UO2 fuel rods with advanced claddings such as M5® under “low pressure–low temperature” or “high pressure–high temperature” water coolant conditions.This article first presents ALCYONE V1.4 RIA-related features and modeling. It especially focuses on recent developments dedicated on the one hand to nonsteady water heat and mass transport and on the other hand to the modeling of grain boundary cracking-induced fission gas release and swelling. This article then compares some simulations of RIA transients performed on UO2-M5® fuel rods in flowing sodium or stagnant water coolant conditions to the relevant experimental results gained from tests performed in either the French CABRI or the Japanese NSRR nuclear transient reactor facilities. It shows in particular to what extent ALCYONE—starting from base irradiation conditions it itself computes—is currently able to handle both the first stage of the transient, namely the pellet-cladding mechanical interaction phase, and the second stage of the transient, should a boiling crisis occur.Areas of improvement are finally discussed with a view to simulating and

  11. 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

  12. 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.

  13. Comparative accident analyses for a KONVOI-type PWR using the integral codes ASTEC V1.33 and MELCOR 1.8.6

    International Nuclear Information System (INIS)

    Reinke, Nils; Erdmann, Walter; Nowack, Holger; Sonnenkalb, Martin

    2010-08-01

    In the frame of the project RS1180 funded by the German Federal Ministry for Economics and Technology (BMWi) calculations have been carried out with the integral code ASTEC V1.33 p3 developed by GRS for two postulated accidents in a nuclear power plant with KONVOI type a pressurized water reactor and compared to calculations with MELCOR 1.8.6 YU. Major objective was to assess the capability of ASTEC for application in level 2 probabilistic safety analyses (PSA). In particular, it was investigated to which extent ASTEC is able to perform such integral calculations meeting criteria with regard to both reasonable calculation time and specific boundary conditions necessary for PSA analyses. Two exemplary accidents were selected: - A transient with loss of steam generator feed water, - A small break loss of coolant accident (50 cm 2 ) in the cold leg of the coolant line connected to the pressurizer. In principle, the results demonstrate the capability of ASTEC V1.33 to carry out such PSA level 2 calculations. In addition, it has to be noted that for both ASTEC and MELCOR the requirements in view of the quality of the results leads to prolonged calculation times due to more detailed nodalisations of the whole plant. This is valid for the core region as well as for the primary circuit and for the containment. Consequently, calculation times in the order of one day to two weeks are accomplished, thereby excluding extensive parameter analyses in order to assess the sensitivity of the calculation results. Concerning the quality of the results a good agreement can be stated between ASTEC and MELCOR results in terms of global data. In detail some results are sensitive to user effects. Here, the nodalisation seems to be of major influence besides differences in modeling specific phenomena. The comparison suggests that in particular the influence of the nodalisation defined by the user and depending on the user's experience should be carefully evaluated. Since some

  14. Colonoscopic allergen provocation test with rBet v 1 in patients with pollen-associated food allergy.

    Science.gov (United States)

    Pickert, C N; Lorentz, A; Manns, M P; Bischoff, S C

    2012-10-01

    After consumption of fruits, nuts, and vegetables, several patients with pollen allergy experience gastrointestinal (GI) tract symptoms that are possibly caused by pollen-associated food allergy. The aim of this study was to evaluate the colonoscopic allergen provocation (COLAP) test using the recombinant birch pollen allergen Bet v 1 (rBet v 1) for in vivo diagnosis of pollen-associated food allergy manifesting in the GI tract. Thirty-four patients with a history of adverse reactions to food, GI tract symptoms, and birch pollen pollinosis and five healthy controls underwent COLAP test. Twenty minutes after endoscopic challenge of the cecal mucosa with rBet v 1, the mucosal wheal and flare reaction was registered semiquantitatively, and tissue biopsy specimens were examined for eosinophil mucosal activation. The mucosal reaction to rBet v 1 was correlated with the presence of pollinosis (P = 0.004), history of adverse reaction to Bet v 1-associated food allergens (P = 0.001), and tissue eosinophils' activation (P foods and in four of 18 (22%) patients with a negative history (P food allergy manifesting in the GI tract. © 2012 John Wiley & Sons A/S.

  15. Hybrid superconducting a.c. current limiter extrapolation 63 kV-1 250 A

    Science.gov (United States)

    Tixador, P.; Levêque, J.; Brunet, Y.; Pham, V. D.

    1994-04-01

    (150 V/50 A) a permis de valider expérimentalement cette conception. Nous aborderons l'extrapolation d'un limiteur de taille industrielle (63 kV/1 250 A). Les résultats seront comparés à des limiteurs supraconducteurs résistifs et de type DASC.

  16. Population activity statistics dissect subthreshold and spiking variability in V1.

    Science.gov (United States)

    Bányai, Mihály; Koman, Zsombor; Orbán, Gergő

    2017-07-01

    Response variability, as measured by fluctuating responses upon repeated performance of trials, is a major component of neural responses, and its characterization is key to interpret high dimensional population recordings. Response variability and covariability display predictable changes upon changes in stimulus and cognitive or behavioral state, providing an opportunity to test the predictive power of models of neural variability. Still, there is little agreement on which model to use as a building block for population-level analyses, and models of variability are often treated as a subject of choice. We investigate two competing models, the doubly stochastic Poisson (DSP) model assuming stochasticity at spike generation, and the rectified Gaussian (RG) model tracing variability back to membrane potential variance, to analyze stimulus-dependent modulation of both single-neuron and pairwise response statistics. Using a pair of model neurons, we demonstrate that the two models predict similar single-cell statistics. However, DSP and RG models have contradicting predictions on the joint statistics of spiking responses. To test the models against data, we build a population model to simulate stimulus change-related modulations in pairwise response statistics. We use single-unit data from the primary visual cortex (V1) of monkeys to show that while model predictions for variance are qualitatively similar to experimental data, only the RG model's predictions are compatible with joint statistics. These results suggest that models using Poisson-like variability might fail to capture important properties of response statistics. We argue that membrane potential-level modeling of stochasticity provides an efficient strategy to model correlations. NEW & NOTEWORTHY Neural variability and covariability are puzzling aspects of cortical computations. For efficient decoding and prediction, models of information encoding in neural populations hinge on an appropriate model of

  17. Chemistry studies in support of Phebus-FP: multicomponent aerosol behaviour. V. 1

    International Nuclear Information System (INIS)

    1992-01-01

    A major programme of integral tests has been completed in the Falcon facility at Winfrith. This two-year programme was designed to study the transport of fission product vapours and aerosols under severe accident conditions. Simulant or trace-irradiated fuel samples were heated up to 2000 deg K together with bulk-reactor materials, and the transport of the released fission products was followed through a pathway that simulated to some degree the upper plenum, hot-leg structures and the containment. Various analytical techniques were used to provide information on the chemical species and physical forms of the release. Mass spectrometry was developed to sample the high-temperature vapours at ambient pressure and determine their chemical forms, on-line gamma-ray spectroscopy was used to distinguish between gas-borne and deposited radionuclides, and speciation samplers (Maypacks) were used to follow the chemical behaviour of iodine within the containment vessel as a function of time. The experiments were designed and analysed with the assistance of modelling specialists to maximize the benefit of this work for the assessment and development of primary circuit and containment codes

  18. DeCART v1.2 User's Manual

    Energy Technology Data Exchange (ETDEWEB)

    Cho, J. Y.; Kim, K. S.; Kim, H. Y.; Lee, C. C.; Zee, S. Q; Joo, H. G

    2007-07-15

    DeCART (Deterministic Core Analysis based on Ray Tracing) is a whole core neutron transport code capable of direct subpin level flux calculation at power generating conditions. It does not require a priori homogenization nor group condensation needed in conventional reactor physics calculations. The depletion and transient calculation capabilities are also available. This manual serves as a self-sufficient guide to use the code. First of all, the various features of the code are explained which encompass various modeling options as well as the basic calculation functionalities. The instructions for running the code are also given with a description of the output files generated. Next, the underlying concepts and principles of preparing a DeCART model for a problem under consideration are presented. Each part of the input needed to specify the geometry, material composition, thermal operating condition, program execution control parameters are explained with examples. The descriptions of all the input cards are then followed. Finally, various sample model inputs ranging from a simple 2D pin cell to a realistic 3D core problem, steady-state to transient problems, and from rectangular to hexagonal core problems are presented.

  19. DeCART v1.1 user's manual

    Energy Technology Data Exchange (ETDEWEB)

    Cho, J. Y.; Kim, K. S.; Kim, H. Y.; Lee, C. C.; Zee, S. Q.; Joo, H. G

    2005-03-15

    DeCART (Deterministic Core Analysis based on Ray Tracing) is a whole core neutron transport code capable of direct subpin level flux calculation at power generating conditions. It does not require a priori homogenization nor group condensation needed in conventional reactor physics calculations. The depletion and transient calculation capabilities are also available. This manual serves as a self-sufficient guide to use the code. First of all, the various features of the code are explained which encompass various modeling options as well as the basic calculation functionalities. The instructions for running the code are also given with a description of the output files generated. Next, the underlying concepts and principles of preparing a DeCART model for a problem under consideration are presented. Each part of the input needed to specify the geometry, material composition, thermal operating condition, program execution control parameters are explained with examples. The descriptions of all the input cards are then followed. Finally, various sample model inputs ranging from a simple 2D pin cell to a realistic 3D core problem, steady-state to transient problems, are presented.

  20. Engineering of beam direct conversion for a 120-kV, 1-MW ion beam

    International Nuclear Information System (INIS)

    Barr, W.L.; Doggett, J.N.; Hamilton, G.W.; Kinney, J.D.; Moir, R.W.

    1977-01-01

    Practical systems for beam direct conversion are required to recover the energy from ion beams at high efficiency and at very high beam power densities in the environment of a high-power, neutral-injection system. Such an experiment is now in progress using a 120-kV beam with a maximum total current of 20 A. After neutralization, the H + component to be recovered will have a power of approximately 1MW. A system testing these concepts has been designed and tested at 15 kV, 2 kW in preparation for the full-power tests. The engineering problems involved in the full-power tests affect electron suppression, gas pumping, voltage holding, diagnostics, and measurement conditions. Planning for future experiments at higher power includes the use of cryopumping and electron suppression by a magnetic field rather than by an electrostatic field. Beam direct conversion for large fusion experiments and reactors will save millions of dollars in the cost of power supplies and electricity and will dispose of the charged beam under conditions that may mot be possible by other techniques

  1. Engineering of beam direct conversion for a 120-kV, 1-MW ion beam

    International Nuclear Information System (INIS)

    Barr, W.L.; Doggett, J.N.; Hamilton, G.W.; Kinney, J.D.; Moir, R.W.

    1977-01-01

    Practical systems for beam direct conversion are required to recover the energy from ion beams at high efficiency and at very high beam power densities in the environment of a high-power, neutral-injection system. Such an experiment is now in progress using a 120-kV beam with a maximum total current of 20 A. After neutralization, the H + component to be recovered will have a power of approximately 1 MW. A system testing these concepts has been designed and tested at 15 kV, 2 kW in preparation for the full-power tests. The engineering problems involved in the full-power tests affect electron suppression, gas pumping, voltage holding, diagnostics, and measurement conditions. Planning for future experiments at higher power includes the use of cryopumping and electron suppression by a magnetic field rather than by an electrostatic field. Beam direct conversion for large fusion experiments and reactors will save millions of dollars in the cost of power supplies and electricity and will dispose of the charged beam under conditions that may not be possible by other techniques

  2. 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

  3. 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

  4. 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.)

  5. 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)

  6. 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

  7. 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.)

  8. 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.)

  9. 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.)

  10. Cardiac sodium channel NaV1.5 distribution in myocytes via interacting proteins: the multiple pool model.

    Science.gov (United States)

    Shy, Diana; Gillet, Ludovic; Abriel, Hugues

    2013-04-01

    The cardiac sodium current (INa) is responsible for the rapid depolarization of cardiac cells, thus allowing for their contraction. It is also involved in regulating the duration of the cardiac action potential (AP) and propagation of the impulse throughout the myocardium. Cardiac INa is generated by the voltage-gated Na(+) channel, NaV1.5, a 2016-residue protein which forms the pore of the channel. Over the past years, hundreds of mutations in SCN5A, the human gene coding for NaV1.5, have been linked to many cardiac electrical disorders, including the congenital and acquired long QT syndrome, Brugada syndrome, conduction slowing, sick sinus syndrome, atrial fibrillation, and dilated cardiomyopathy. Similar to many membrane proteins, NaV1.5 has been found to be regulated by several interacting proteins. In some cases, these different proteins, which reside in distinct membrane compartments (i.e. lateral membrane vs. intercalated disks), have been shown to interact with the same regulatory domain of NaV1.5, thus suggesting that several pools of NaV1.5 channels may co-exist in cardiac cells. The aim of this review article is to summarize the recent works that demonstrate its interaction with regulatory proteins and illustrate the model that the sodium channel NaV1.5 resides in distinct and different pools in cardiac cells. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Cardiac Pathways of Differentiation, Metabolism and Contraction. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Performance of the Adult ADHD Self-Report Scale-v1.1 in Adults with Major Depressive Disorder

    Directory of Open Access Journals (Sweden)

    Boadie W. Dunlop

    2018-03-01

    Full Text Available Attention deficit/hyperactivity disorder (ADHD is an under-recognized comorbid disorder among patients with mood disorders. ADHD is an independent risk factor for suicidal ideation and behavior and contributes to many aspects of impaired function in adults. Diagnosis of ADHD in Major Depressive Disorder (MDD patients is challenging due to the overlap in cognitive symptoms between the two disorders. The ADHD Self-Report Scale, version 1.1 (ASRS-v1.1 is a widely used screening instrument for ADHD in adults but its accuracy has not been evaluated previously in treatment-seeking MDD patients. We administered the ASRS-v1.1 to 55 healthy controls and 40 adults with a primary psychiatric diagnosis of MDD who were participating in clinical research studies. ADHD diagnosis was assessed via structured interview with the adult ADHD module of the Mini International Neuropsychiatric Interview Plus version 6.0.0 (MINI along with a psychiatrist’s assessment. Overall, full-syndrome ADHD was diagnosed in 12.5% of the MDD patients. MDD patients endorsed all 18 items of the ASRS-v1.1 more frequently than the healthy controls and the number of ASRS-v1.1 items endorsed correlated with levels of anxiety in the MDD patients. The ASRS-v1.1 demonstrated fair performance for identifying full syndrome DSM-IV ADHD diagnosis, with sensitivity 60%, specificity: 68.6%, positive predictive value 21.4%, negative predictive value 92.3% and total classification accuracy of 67.5%. Positive predictive value improved substantially when the ADHD criterion requiring symptom onset before age 7 was omitted. In adult MDD patients, a negative ASRS-v1.1 screen strongly suggests the absence of ADHD but positive screen results require careful evaluation to determine whether self-reported ADHD symptoms simply emerge from depression or whether comorbid ADHD is present.

  12. Theoretical understanding on the v(1)-SO4(2-) band perturbed by the formation of magnesium sulfate ion pairs.

    Science.gov (United States)

    Zhang, Hao; Zhang, Yun-Hong; Wang, Feng

    2009-02-01

    The factors determining the spectroscopic characteristics of the v(1)-SO4(2-) band of the MgSO4 ion pairs are discussed via ab initio calculation, including coupling effect, hydrogen bonding effect, and direct contact effect of Mg2+ with SO4(2-). With the calculation of the heavy water hydrated contact ion pairs (CIP), the overlap between the librations of water and the v(1)-SO4(2-) band can be separated, and thus the coupling effect is abstracted, and this coupling effect leads to a blue shift for the v(1)-SO4(2-) band of 5.6 cm(-1) in the monodentate CIP and 3.6 cm(-1) in the bidentate CIP. The hydrogen bonding between each water molecule without relation to Mg2+ and the sulfate ion makes the v(1)-SO4(2-) band blue shift of 3.7 cm(-1). When the outer-sphere water around Mg2+ are hydrogen bonded between SO4(2-) and Mg2+, it will make the largest disturbance to the v(1)-SO4(2-) band. Moreover, the inner-sphere water can affect the v(1)-SO4(2-) band conjunct with the direct contact of Mg2+ with SO4(2-), showing a blue shift of 14.4 cm(-1) in the solvent-shared ion pair, 22.6 cm(-1) in the monodentate CIP, 4.3 cm(-1) in the bidentate CIP, and 21.4 cm(-1) in the tridentate CIP. At last, the Raman spectral evolution in the efflorescence production process is tried to be rationalized. The shoulder at 995 cm(-1) is attributed to the monodentate CIP with 2-3 outer-sphere water molecules, whereas the new peak at 1021 cm(-1) at high concentration is assigned to the formation of aqueous triple ion.

  13. 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

  14. Nuclear energetics as environmentally affable source - present and and future

    International Nuclear Information System (INIS)

    Suchomel, J.

    2002-01-01

    In this paper the situation in nuclear energetics in the world in 2000 year is presented. Climatic changes initiated by burning of the fossil fuels an influence of nuclear energetics are discussed. Author informs that European Union and U.S.A. supports developing of nuclear energetics. Nuclear phobia from radiation risk of some inhabitants is compared with risks of other man activities. Possibilities of the electricity production by alternative sources are compared. Liability of the Slovak Republic for decommissioning of two reactor of the V-1 Jaslovske Bohunice NPP in 2006 and 2008, which is compared with the Program of safety improvement of these reactors are discussed. Author and Slovak Nuclear Society accept gladly the suggestion of government of the Slovak Republic that they reassess this liability. The best alternative for decommissioned Jaslovske Bohunice NPP will be the completion of the 3 rd and 4 th blocks of the Mochovce NPP

  15. Distribution of calcium channel Ca(V)1.3 immunoreactivity in the rat spinal cord and brain stem.

    Science.gov (United States)

    Sukiasyan, N; Hultborn, H; Zhang, M

    2009-03-03

    The function of local networks in the CNS depends upon both the connectivity between neurons and their intrinsic properties. An intrinsic property of spinal motoneurons is the presence of persistent inward currents (PICs), which are mediated by non-inactivating calcium (mainly Ca(V)1.3) and/or sodium channels and serve to amplify neuronal input signals. It is of fundamental importance for the prediction of network function to determine the distribution of neurons possessing the ion channels that produce PICs. Although the distribution pattern of Ca(V)1.3 immunoreactivity (Ca(V)1.3-IR) has been studied in some specific central nervous regions in some species, so far no systematic investigations have been performed in both the rat spinal cord and brain stem. In the present study this issue was investigated by immunohistochemistry. The results indicated that the Ca(V)1.3-IR neurons were widely distributed across different parts of the spinal cord and the brain stem although with variable labeling intensities. In the spinal gray matter large neurons in the ventral horn (presumably motoneurons) tended to display higher levels of immunoreactivity than smaller neurons in the dorsal horn. In the white matter, a subset of glial cells labeled by an oligodendrocyte marker was also Ca(V)1.3-positive. In the brain stem, neurons in the motor nuclei appeared to have higher levels of immunoreactivity than those in the sensory nuclei. Moreover, a number of nuclei containing monoaminergic cells, for example the locus coeruleus, were also strongly immunoreactive. Ca(V)1.3-IR was consistently detected in the neuronal perikarya regardless of the neuronal type. However, in the large neurons in the spinal ventral horn and the cranial motor nuclei the Ca(V)1.3-IR was clearly detectable in first and second order dendrites. These results indicate that in the rat spinal cord and brain stem Ca(V)1.3 is probably a common calcium channel used by many kinds of neurons to facilitate the neuronal

  16. Persistent modification of Na{sub v}1.9 following chronic exposure to insecticides and pyridostigmine bromide

    Energy Technology Data Exchange (ETDEWEB)

    Nutter, Thomas J., E-mail: tnutter@dental.ufl.edu; Cooper, Brian Y., E-mail: bcooper@dental.ufl.edu

    2014-06-15

    Many veterans of the 1991 Gulf War (GW) returned from that conflict with a widespread chronic pain affecting deep tissues. Recently, we have shown that a 60 day exposure to the insecticides permethrin, chlorpyrifos, and pyridostigmine bromide (NTPB) had little influence on nociceptor action potential forming Na{sub v}1.8, but increased K{sub v}7 mediated inhibitory currents 8 weeks after treatment. Using the same exposure regimen, we used whole cell patch methods to examine whether the influences of NTPB could be observed on Na{sub v}1.9 expressed in muscle and vascular nociceptors. During a 60 day exposure to NTPB, rats exhibited lowered muscle pain thresholds and increased rest periods, but these measures subsequently returned to normal levels. Eight and 12 weeks after treatments ceased, DRG neurons were excised from the sensory ganglia. Whole cell patch studies revealed little change in voltage dependent activation and deactivation of Na{sub v}1.9, but significant increases in the amplitude of Na{sub v}1.9 were observed 8 weeks after exposure. Cellular studies, at the 8 week delay, revealed that NTPB also significantly prolonged action potential duration and afterhyperpolarization (22 °C). Acute application of permethrin (10 μM) also increased the amplitude of Na{sub v}1.9 in skin, muscle and vascular nociceptors. In conclusion, chronic exposure to Gulf War agents produced long term changes in the amplitude of Na{sub v}1.9 expressed in muscle and vascular nociceptors. The reported increases in K{sub v}7 amplitude may have been an adaptive response to increased Na{sub v}1.9, and effectively suppressed behavioral pain measures in the post treatment period. Factors that alter the balance between Na{sub v}1.9 and K{sub v}7 could release spontaneous discharge and produce chronic deep tissue pain. - Highlights: • Rats were treated 60 days with permethrin, chlorpyrifos and pyridostigmine bromide. • 8 weeks after treatments, Nav1.9 activation and deactivation were

  17. 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.)

  18. Modernized accurate methods for processing of in-core measurement signals in WWER reactors

    International Nuclear Information System (INIS)

    Polak, T.

    1996-01-01

    Utilization of the new accurate WIMS-KAERI library (WIMKAL-88) to generate the following characteristics for Rhodium SPND: Sensitivity depletion law by high (approx= 75%) burnup of emitter; influence of burnup-history on depletion law course; influence of neutron spectrum change on Rh-SPND sensitivity caused by change of fuel enrichment, fuel burnup, moderator temperature, concentration of boracid, central pin power rate and concentration of Xe 135 ; generating and experimental testing of Rh-SPND signal to linear pin power rate and signal to neutron flux conversion factors. Rh-SPND instrumentation optimization (reduction) related to safety and operational aspects as needed for 3D power surveillance in WWER-1000 reactors. Analysis of SPND reduction from 64x7 to 46x7 by method of Shannon information entropy optimization. Influence of reduction on accuracy of 3D power distribution reconstruction. Physical methods of 3D power distribution unfolding in new modernized on-line I and C system in NPP J. Bohunice with in-core measurements according to 210 thermocouples and 36x7 Rh-SPNDs. Program system TOPRE under QNX operating system network in FORTRAN 77, neutronic background calculations by macrocode MOBY-DICK. (author). 10 refs, 6 figs, 7 tabs

  19. A successful approach for the implementation of symptom-based emergency operating procedures for VVER reactors

    International Nuclear Information System (INIS)

    Lhoest, V.; Prior, R.; Pascal, G.

    2000-01-01

    The paper provides an overview of the organization, the progress and the results of the various Emergence Operating Procedure (EOP) development programs for VVER type reactors conducted by Westinghouse so far. The detailed working process is presented through the solutions to some major plant issues. The EOPs have been developed for the Temelin, Dukovany, Bohunice, Mochovce and Paks VVER nuclear power plants. The procedures are developed in working teams of experts from the utility and Westinghouse. The completion of the programs constitute an indication of the overall success of this approach. This is further reinforced by the general acceptance of the new procedures by the plant personnel, together with the good results obtained so far from procedure testing. This is also confirmed by a new PSA-level 1 analysis for Dukovany plant, which shows a significant improvement in the overall plant safety. This means a 20% reduction in the Core Damage Frequency due to the introduction of the new EOPs. The fact that some modifications have been implemented to the plants to solve design weaknesses identified in the course of this programs also constitute a positive result

  20. 76 FR 13082 - Amendment of VOR Federal Airways V-1, V-7, V-11 and V-20; Kona, HI

    Science.gov (United States)

    2011-03-10

    ... V-20; Kona, HI AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: This action amends four VHF Omnidirectional Range (VOR) Federal airways in the vicinity of Kona, HI; V- 1, V-7... Keahole Airport property Kailua-Kona, HI. This will enhance the management of aircraft operations over...

  1. Transcriptional and electrophysiological consequences of KChIP2-mediated regulation of CaV1.2

    DEFF Research Database (Denmark)

    Thomsen, Morten B; Foster, Erika; Nguyen, Katherine H

    2009-01-01

    previous finding. Using gene-chip and real-time PCR techniques, we find that KChIP2(-/-) mice have an increased transcriptional activity of the calcium channel beta(2) subunit, CACNB2, whereas the expression of Ca(V)1.2 is preserved. Although I(to,f) is absent and I(Ca,L) is decreased in myocytes from KCh...

  2. TENCompetence Learning Design Toolkit, Runtime component, ccsi_v3_2_10c_v1_4

    NARCIS (Netherlands)

    Sharples, Paul; Popat, Kris; Llobet, Lau; Santos, Patricia; Hernández-Leo, Davinia; Miao, Yongwu; Griffiths, David; Beauvoir, Phillip

    2010-01-01

    Sharples, P., Popat, K., Llobet, L., Santos, P., Hernandez-Leo, D., Miao, Y., Griffiths, D. & Beauvoir, P. (2009) TENCompetence Learning Design Toolkit, Runtime component, ccsi_v3_2_10c_v1_4 This release is composed of three files corresponding to CopperCore Service Integration (CCSI) v3.2-10cv1.4,

  3. Non-volatile resistive switching in the Mott insulator (V1-xCrx)2O3

    Science.gov (United States)

    Querré, M.; Tranchant, J.; Corraze, B.; Cordier, S.; Bouquet, V.; Députier, S.; Guilloux-Viry, M.; Besland, M.-P.; Janod, E.; Cario, L.

    2018-05-01

    The discovery of non-volatile resistive switching in Mott insulators related to an electric-field-induced insulator to metal transition (IMT) has paved the way for their use in a new type of non-volatile memories, the Mott memories. While most of the previous studies were dedicated to uncover the resistive switching mechanism and explore the memory potential of chalcogenide Mott insulators, we present here a comprehensive study of resistive switching in the canonical oxide Mott insulator (V1-xCrx)2O3. Our work demonstrates that this compound undergoes a non-volatile resistive switching under electric field. This resistive switching is induced by a Mott transition at the local scale which creates metallic domains closely related to existing phases of the temperature-pressure phase diagram of (V1-xCrx)2O3. Our work demonstrates also reversible resistive switching in (V1-xCrx)2O3 crystals and thin film devices. Preliminary performances obtained on 880 nm thick layers with 500 nm electrodes show the strong potential of Mott memories based on the Mott insulator (V1-xCrx)2O3.

  4. Development of a human vasopressin V-1a-receptor antagonist from an evolutionary-related insect neuropeptide

    Czech Academy of Sciences Publication Activity Database

    Di Giglio, M. G.; Muttenthaler, M.; Harpsoe, K.; Liutkeviciute, Z.; Keov, P.; Eder, T.; Rattei, T.; Arrowsmith, S.; Wray, S.; Marek, Aleš; Elbert, Tomáš; Alewood, P. F.; Gloriam, D. E.; Gruber, C. W.

    2017-01-01

    Roč. 7, Feb 1 (2017), č. článku 41002. ISSN 2045-2322 Institutional support: RVO:61388963 Keywords : neuropeptide * inotocin * V1aR-antagonist Subject RIV: CE - Biochemistry OBOR OECD: Biochemistry and molecular biology Impact factor: 4.259, year: 2016 https://www.nature.com/articles/srep41002

  5. V1 and v2b interneurons secure the alternating flexor-extensor motor activity mice require for limbed locomotion.

    Science.gov (United States)

    Zhang, Jingming; Lanuza, Guillermo M; Britz, Olivier; Wang, Zhi; Siembab, Valerie C; Zhang, Ying; Velasquez, Tomoko; Alvarez, Francisco J; Frank, Eric; Goulding, Martyn

    2014-04-02

    Reciprocal activation of flexor and extensor muscles constitutes the fundamental mechanism that tetrapod vertebrates use for locomotion and limb-driven reflex behaviors. This aspect of motor coordination is controlled by inhibitory neurons in the spinal cord; however, the identity of the spinal interneurons that serve this function is not known. Here, we show that the production of an alternating flexor-extensor motor rhythm depends on the composite activities of two classes of ventrally located inhibitory neurons, V1 and V2b interneurons (INs). Abrogating V1 and V2b IN-derived neurotransmission in the isolated spinal cord results in a synchronous pattern of L2 flexor-related and L5 extensor-related locomotor activity. Mice lacking V1 and V2b inhibition are unable to articulate their limb joints and display marked deficits in limb-driven reflex movements. Taken together, these findings identify V1- and V2b-derived neurons as the core interneuronal components of the limb central pattern generator (CPG) that coordinate flexor-extensor motor activity. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. 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

  7. 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.)

  8. Nuclear reactor

    International Nuclear Information System (INIS)

    Sakurai, Mikio; Yamauchi, Koki.

    1983-01-01

    Purpose: To improve the channel stability and the reactor core stability in a spontaneous circulation state of coolants. Constitution: A reactor core stabilizing device comprising a differential pressure automatic ON-OFF valve is disposed between each of a plurality of jet pumps arranged on a pump deck. The stabilizing device comprises a piston exerted with a pressure on the lower side of the pump deck by way of a pipeway and a valve for flowing coolants through the bypass opening disposed to the pump deck by the opening and closure of the valve ON-OFF. In a case where the jet pumps are stopped, since the differential pressure between the upper and the lower sides of the pump deck is removed, the valve lowers gravitationally into an opened state, whereby the coolants flow through the bypass opening to increase the spontaneous circulation amount thereby improve the stability. (Yoshino, Y.)

  9. Nuclear reactor

    International Nuclear Information System (INIS)

    Aleite, W.; Bock, H.W.; Struensee, S.

    1976-01-01

    The invention concerns the use of burnable poisons in a nuclear reactor, especially in PWRs, in order to improve the controllability of the reactor. An unsymmetrical arrangement in the lattice is provided, if necessary also by insertion of special rods for these additions. It is proposed to arrange the burnable poisons in fuel elements taken over from a previous burn-up cycle and to distribute them, going out from the side facing the control rods, over not more than 20% of the lenth of the fuel elements. It seems sufficient, for the burnable poisons to bind an initial reactivity of only 0.1% and to become ineffective after normal operation of 3 to 4 months. (ORU) [de

  10. Reactor container

    International Nuclear Information System (INIS)

    Ichiki, Tadaharu; Saba, Kazuhisa.

    1979-01-01

    Purpose: To improve the earthquake resistance as well as reduce the size of a container for a nuclear reactor with no adverse effects on the decrease of impact shock to the container and shortening of construction step. Constitution: Reinforcing profile steel materials are welded longitudinally and transversely to the inner surface of a container, and inner steel plates are secured to the above profile steel materials while keeping a gap between the materials and the container. Reactor shielding wall planted to the base concrete of the container is mounted to the pressure vessel, and main steam pipeways secured by the transverse beams and led to the outside of container is connected. This can improve the rigidity earthquake strength and the safetiness against the increase in the inside pressure upon failures of the container. (Yoshino, Y.)

  11. Reactor container

    International Nuclear Information System (INIS)

    Oyamada, Osamu; Furukawa, Hideyasu; Uozumi, Hiroto.

    1979-01-01

    Purpose: To lower the position of an intermediate slab within a reactor container and fitting a heat insulating material to the inner wall of said intermediate slab, whereby a space for a control rod exchanging device and thermal stresses of the inner peripheral wall are lowered. Constitution: In the pedestal at the lower part of a reactor pressure vessel there is formed an intermediate slab at a position lower than diaphragm floor slab of the outer periphery of the pedestal thereby to secure a space for providing automatic exchanging device of a control rod driving device. Futhermore, a heat insulating material is fitted to the inner peripheral wall at the upper side of the intermediate slab part, and the temperature gradient in the wall thickness direction at the time of a piping rupture trouble is made gentle, and thermal stresses at the inner peripheral wall are lowered. (Sekiya, K.)

  12. Functional alterations of V1 cortex in patients with primary open angle glaucoma using functional MRI retinotopic mapping

    International Nuclear Information System (INIS)

    Shi Linping; Cai Ping; Li Changying; Li Xueqin; Xie Bing; Li Sha; Liu Ting; Chen Xing; Shi Yanshu; Wang Jian

    2011-01-01

    Objective: To evaluate the functional changes of visual cortex (V1) in patients with primary open angle glaucoma (POAG) by fMRI retinotopic mapping technology. Methods: Fifteen POAG patients and 15 healthy volunteers underwent stimulations with fMRI retinotopic mapping stimulus and contrast-reversing checkerboard patterns stimulus on a Siemens Trio 3.0 T MRI whole-body scanner for functional data collection. Comparisons of V1 fMRI responses between the glaucomatous eyes and the healthy eyes of the patients were carried out using paired samples t-test, while independent samples t-test was used to compare V1 fMRI responses and activations between the healthy eyes of patients and the age-, gender- and side- matched eyes of normal people. Differences of V1 cortical functions and visual functions were analyzed by linear correlation analysis when the glaucomatous and the healthy eyes were simulated individually., Results: (1) V1 fMRI responses of the individually stimulated glaucomatous eyes [(1.24±0.72)%] were weaker than those of the healthy eyes [(2.18±0.93)%] (t=4.757, P 0.05). (2) Differences of V1 cortical functions were negatively correlated with those of visual functions in the individually stimulated glaucomatous and healthy eyes (r=-0.887, P< 0.01). (3) The activated area indexes of V1 cortexes in the healthy eyes from patients (0.72±0.12) were lower than those in the matched eyes of normal people (0.85±0.09) (t=-3.801, P<0.01) . Conclusion: Cortical function impairment was in accordance with visual function impairment in glaucoma. Located and quantified measurement with fMRI retinotopic mapping was a useful method for clinical follow-up and evaluation of functional alteration of glaucomatous visual cortex, and a potentially useful means of studying trans-synaptic degeneration of visual pathways of in vivo glaucoma. (authors)

  13. Neutronic reactor

    International Nuclear Information System (INIS)

    Lewis, W.R.

    1978-01-01

    Disclosed is a graphite-moderated, water-cooled nuclear reactor including a plurality of rectangular graphite blocks stacked in abutting relationship in layers, alternate layers having axes which are normal to one another, alternate rows of blocks in alternate layers being provided with a channel extending through the blocks, said channeled blocks being provided with concave sides and having smaller vertical dimensions than adjacent blocks in the same layer, there being nuclear fuel in the channels

  14. Nuclear reactors

    International Nuclear Information System (INIS)

    Humphreys, P.; Davidson, D.F.; Thatcher, G.

    1980-01-01

    The cooling system of a liquid metal cooled fast breeder nuclear reactor of the pool kind is described. It has an intermediate heat exchange module comprising a tube-in-shell heat exchanger and an electromagnetic flow coupler in the base region of the module. Primary coolant is flowed through the heat exchanger being driven by electromagnetic interaction with secondary liquid metal coolant flow effected by a mechanical pump. (author)

  15. Nuclear reactor

    International Nuclear Information System (INIS)

    Jungmann, A.

    1975-01-01

    Between a PWR's reactor pressure vessel made of steel and the biological shield made of concrete there is a gap. This gap is filled up with a heat insulation facting the reactor pressure vessel, for example with insulating concrete segments jacketed with sheet steel and with an additional layer. This layer serves for smooth absorption of compressive forces originating in radial direction from the reactor pressure vessel. It consists of cylinder-segment shaped bricks made of on situ concrete, for instance. The bricks have cooling agent ports in one or several rows which run parallel to the wall of the pressure vessel and in alignment with superposed bricks. Between the layer of bricks and the biological shield or rather the heat insulation, there are joints which are filled, however, with injected mortar. That guarantees a smooth series of connected components resistant tom compression. Besides, a slip foil can be set between the heat insulation and the joining joint filled with mortar for the reduction of the friction at thermal expansions. (TK) [de

  16. Reactor building

    International Nuclear Information System (INIS)

    Ebata, Sakae.

    1990-01-01

    At least one valve rack is disposed in a reactor building, on which pipeways to a main closure valve, valves and bypasses of turbines are placed and contained. The valve rack is fixed to the main body of the building or to a base mat. Since the reactor building is designed as class A earthquake-proofness and for maintaining the S 1 function, the valve rack can be fixed to the building main body or to the base mat. With such a constitution, the portions for maintaining the S 1 function are concentrated to the reactor building. As a result, the dispersion of structures of earthquake-proof portion corresponding to the reference earthquake vibration S 1 can be prevented. Accordingly, the conditions for the earthquake-proof design of the turbine building and the turbine/electric generator supporting rack are defined as only the class B earthquake-proof design conditions. In view of the above, the amount of building materials can be saved and the time for construction can be shortened. (I.S.)

  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. MLR reactor

    International Nuclear Information System (INIS)

    Ryazantsev, E.P.; Egorenkov, P.M.; Nasonov, V.A.; Smimov, A.M.; Taliev, A.V.; Gromov, B.F.; Kousin, V.V.; Lantsov, M.N.; Radchenko, V.P.; Sharapov, V.N.

    1998-01-01

    The Material Testing Loop Reactor (MLR) development was commenced in 1991 with the aim of updating and widening Russia's experimental base to validate the selected directions of further progress of the nuclear power industry in Russia and to enhance its reliability and safety. The MLR reactor is the pool-type one. As coolant it applies light water and as side reflector beryllium. The direction of water circulation in the core is upward. The core comprises 30 FA arranged as hexagonal lattice with the 90-95 mm pitch. The central materials channel and six loop channels are sited in the core. The reflector includes up to 11 loop channels. The reactor power is 100 MW. The average power density of the core is 0.4 MW/I (maximal value 1.0 MW/l). The maximum neutron flux density is 7.10 14 n/cm 2 s in the core (E>0.1 MeV), and 5.10 14 n/cm 2 s in the reflector (E<0.625 eV). In 1995 due to the lack of funding the MLR designing was suspended. (author)

  19. Nuclear reactor

    International Nuclear Information System (INIS)

    Shirakawa, Toshihisa.

    1979-01-01

    Purpose: To prevent cladding tube injuries due to thermal expansion of each of the pellets by successively extracting each of the control rods loaded in the reactor core from those having less number of notches, as well as facilitate the handling work for the control rods. Constitution: A recycle flow control device is provided to a circulation pump for forcibly circulating coolants in the reactor container and an operational device is provided for receiving each of the signals concerning number of notches for each of the control rods and flow control depending on the xenon poisoning effect obtained from the signals derived from the in-core instrument system connected to the reactor core. The operational device is connected with a control rod drive for moving each of the control rods up and down and a recycle flow control device. The operational device is set with a pattern for the aimed control rod power and the sequence of extraction. Upon extraction of the control rods, they are extracted successively from those having less notch numbers. (Moriyama, K.)

  20. Reactor container

    International Nuclear Information System (INIS)

    Hidaka, Masataka; Hatamiya, Shigeo; Kawasaki, Terufumi; Fukui, Toru; Suzuki, Hiroaki; Kataoka, Yoshiyuki; Kawabe, Ryuhei; Murase, Michio; Naito, Masanori.

    1990-01-01

    In order to suppress the pressure elevation in a reactor container due to high temperature and high pressure steams jetted out upon pipeway rupture accidents in the reactor container, the steams are introduced to a pressure suppression chamber for condensating them in stored coolants. However, the ability for suppressing the pressure elevation and steam coagulation are deteriorated due to the presence of inactive incondensible gases. Then, there are disposed a vent channel for introducing the steams in a dry well to a pressure suppression chamber in the reactor pressure vessel, a closed space disposed at the position lower than a usual liquid level, a first channel having an inlet in the pressure suppression chamber and an exit in the closed space and a second means connected by way of a backflow checking means for preventing the flow directing to the closed space. The first paths are present by plurality, a portion of which constitutes a syphon. The incondensible gases and the steams are discharged to the dry well at high pressure by using the difference of the water head for a long cooling time after the pipeway rupture accident. Then, safety can be improved without using dynamic equipments as driving source. (N.H.)

  1. Reactor core in FBR type reactor

    International Nuclear Information System (INIS)

    Masumi, Ryoji; Kawashima, Katsuyuki; Kurihara, Kunitoshi.

    1989-01-01

    In a reactor core in FBR type reactors, a portion of homogenous fuels constituting the homogenous reactor core is replaced with multi-region fuels in which the enrichment degree of fissile materials is lower nearer to the axial center. This enables to condition the composition such that a reactor core having neutron flux distribution either of a homogenous reactor core or a heterogenous reactor core has substantially identical reactivity. Accordingly, in the transfer from the homogenous reactor core to the axially heterogenous reactor core, the average reactivity in the reactor core is substantially equal in each of the cycles. Further, by replacing a portion of the homogenous fuels with a multi-region fuels, thereby increasing the heat generation near the axial center, it is possiable to reduce the linear power output in the regions above and below thereof and, in addition, to improve the thermal margin in the reactor core. (T.M.)

  2. fMRI orientation decoding in V1 does not require global maps or globally coherent orientation stimuli.

    Science.gov (United States)

    Alink, Arjen; Krugliak, Alexandra; Walther, Alexander; Kriegeskorte, Nikolaus

    2013-01-01

    The orientation of a large grating can be decoded from V1 functional magnetic resonance imaging (fMRI) data, even at low resolution (3-mm isotropic voxels). This finding has suggested that columnar-level neuronal information might be accessible to fMRI at 3T. However, orientation decodability might alternatively arise from global orientation-preference maps. Such global maps across V1 could result from bottom-up processing, if the preferences of V1 neurons were biased toward particular orientations (e.g., radial from fixation, or cardinal, i.e., vertical or horizontal). Global maps could also arise from local recurrent or top-down processing, reflecting pre-attentive perceptual grouping, attention spreading, or predictive coding of global form. Here we investigate whether fMRI orientation decoding with 2-mm voxels requires (a) globally coherent orientation stimuli and/or (b) global-scale patterns of V1 activity. We used opposite-orientation gratings (balanced about the cardinal orientations) and spirals (balanced about the radial orientation), along with novel patch-swapped variants of these stimuli. The two stimuli of a patch-swapped pair have opposite orientations everywhere (like their globally coherent parent stimuli). However, the two stimuli appear globally similar, a patchwork of opposite orientations. We find that all stimulus pairs are robustly decodable, demonstrating that fMRI orientation decoding does not require globally coherent orientation stimuli. Furthermore, decoding remained robust after spatial high-pass filtering for all stimuli, showing that fine-grained components of the fMRI patterns reflect visual orientations. Consistent with previous studies, we found evidence for global radial and vertical preference maps in V1. However, these were weak or absent for patch-swapped stimuli, suggesting that global preference maps depend on globally coherent orientations and might arise through recurrent or top-down processes related to the perception of

  3. Allergy immunotherapy with a hypoallergenic recombinant birch pollen allergen rBet v 1-FV in a randomized controlled trial.

    Science.gov (United States)

    Klimek, Ludger; Bachert, Claus; Lukat, Karl-Friedrich; Pfaar, Oliver; Meyer, Hanns; Narkus, Annemie

    2015-01-01

    Pollen extracts and chemically modified allergoids are used successfully in allergen immunotherapy (AIT). Recombinant extracts offer potential advantages with respect to pharmaceutical quality, standardization and dosing. A hypoallergenic recombinant folding variant of the major birch pollen allergen (rBet v 1-FV) was compared with an established native birch preparation. A pre-seasonal, randomized, actively controlled phase II study was performed in birch pollen allergic rhino-conjunctivitis with or without asthma, GINA I/ II. 51 patients (24 rBet v 1-FV, 27 native extract) started therapy with subcutaneous allergen immunotherapy (SCIT). Primary end-point was a combined symptom medication score (SMS), changes in nasal provocation test, visual rating score and specific antibody responses secondary end-points. After one pre-seasonal treatment course the combined SMS was 5.86 (median; IQR: 14.02) for the rBet v 1-FV group versus 12.40 (median; IQR: 9.32) for the comparator during the three weeks pollen season (p = 0.330). After treatment in the second year, scores were 3.00 (median; IQR: 6.50) and 2.93 (4.86) respectively. Allergen tolerance in a nasal provocation test improved to a comparable extent in both groups. Significant increases in birch pollen-specific IgG1 and IgG4 were observed in both treatment groups following the first treatment phase and remained significantly raised until the end of the study. In this first in man, proof of concept phase II trial no statistical difference between rBet v 1-FV and an established natural pollen extract could be observed. rBet v 1-FV could be administered in higher doses than the native protein with no increase in adverse effects. The study was registered in clinicalTrials.gov (NCT00266526).

  4. Pyramidal cells in V1 of African rodents are bigger more branched and more spiny than those in primates.

    Directory of Open Access Journals (Sweden)

    Guy eElston

    2014-02-01

    Full Text Available Pyramidal cells are characterised by markedly different sized dendritic trees, branching patterns and spine density across the cortical mantle. Moreover, pyramidal cells have been shown to differ in structure among homologous cortical areas in different species; however, most of these studies have been conducted in primates. Whilst pyramidal cells have been quantified in a few cortical areas in some other species there are, as yet, no uniform comparative data on pyramidal cell structure in a homologous cortical area among species in different Orders. Here we studied layer III pyramidal cells in V1 of three species of rodents, the greater cane rat, highveld gerbil and four-striped mouse, by the same methodology used to sample data from layer III pyramidal cells in primates. The data reveal markedly different trends between rodents and primates: there is an appreciable increase in the size, branching complexity and number of spines in the dendritic trees of pyramidal cells with increasing size of V1 in the brain in rodents, whereas there is relatively little difference in primates. Moreover, pyramidal cells in rodents are larger, more branched and more spinous than those in primates. For example, the dendritic trees of pyramidal cells in V1 of the cane rat are nearly three times larger, and have more than ten times the number of spines in their basal dendritic trees, than those in V1 of the macaque (7900 and 600, respectively, which has a V1 40 times the size that of the cane rat. It remains to be determined to what extent these differences may result from developmental differences or reflect evolutionary and/or processing specializations.

  5. Systematic Study of Binding of μ-Conotoxins to the Sodium Channel NaV1.4

    Directory of Open Access Journals (Sweden)

    Somayeh Mahdavi

    2014-12-01

    Full Text Available Voltage-gated sodium channels (NaV are fundamental components of the nervous system. Their dysfunction is implicated in a number of neurological disorders, such as chronic pain, making them potential targets for the treatment of such disorders. The prominence of the NaV channels in the nervous system has been exploited by venomous animals for preying purposes, which have developed toxins that can block the NaV channels, thereby disabling their function. Because of their potency, such toxins could provide drug leads for the treatment of neurological disorders associated with NaV channels. However, most toxins lack selectivity for a given target NaV channel, and improving their selectivity profile among the NaV1 isoforms is essential for their development as drug leads. Computational methods will be very useful in the solution of such design problems, provided accurate models of the protein-ligand complex can be constructed. Using docking and molecular dynamics simulations, we have recently constructed a model for the NaV1.4-μ-conotoxin-GIIIA complex and validated it with the ample mutational data available for this complex. Here, we use the validated NaV1.4 model in a systematic study of binding other μ-conotoxins (PIIIA, KIIIA and BuIIIB to NaV1.4. The binding mode obtained for each complex is shown to be consistent with the available mutation data and binding constants. We compare the binding modes of PIIIA, KIIIA and BuIIIB to that of GIIIA and point out the similarities and differences among them. The detailed information about NaV1.4-μ-conotoxin interactions provided here will be useful in the design of new NaV channel blocking peptides.

  6. Development of a human vasopressin V1a-receptor antagonist from an evolutionary-related insect neuropeptide

    Science.gov (United States)

    di Giglio, Maria Giulia; Muttenthaler, Markus; Harpsøe, Kasper; Liutkeviciute, Zita; Keov, Peter; Eder, Thomas; Rattei, Thomas; Arrowsmith, Sarah; Wray, Susan; Marek, Ales; Elbert, Tomas; Alewood, Paul F.; Gloriam, David E.; Gruber, Christian W.

    2017-02-01

    Characterisation of G protein-coupled receptors (GPCR) relies on the availability of a toolbox of ligands that selectively modulate different functional states of the receptors. To uncover such molecules, we explored a unique strategy for ligand discovery that takes advantage of the evolutionary conservation of the 600-million-year-old oxytocin/vasopressin signalling system. We isolated the insect oxytocin/vasopressin orthologue inotocin from the black garden ant (Lasius niger), identified and cloned its cognate receptor and determined its pharmacological properties on the insect and human oxytocin/vasopressin receptors. Subsequently, we identified a functional dichotomy: inotocin activated the insect inotocin and the human vasopressin V1b receptors, but inhibited the human V1aR. Replacement of Arg8 of inotocin by D-Arg8 led to a potent, stable and competitive V1aR-antagonist ([D-Arg8]-inotocin) with a 3,000-fold binding selectivity for the human V1aR over the other three subtypes, OTR, V1bR and V2R. The Arg8/D-Arg8 ligand-pair was further investigated to gain novel insights into the oxytocin/vasopressin peptide-receptor interaction, which led to the identification of key residues of the receptors that are important for ligand functionality and selectivity. These observations could play an important role for development of oxytocin/vasopressin receptor modulators that would enable clear distinction of the physiological and pathological responses of the individual receptor subtypes.

  7. A novel NaV1.5 voltage sensor mutation associated with severe atrial and ventricular arrhythmias.

    Science.gov (United States)

    Wang, Hong-Gang; Zhu, Wandi; Kanter, Ronald J; Silva, Jonathan R; Honeywell, Christina; Gow, Robert M; Pitt, Geoffrey S

    2016-03-01

    Inherited autosomal dominant mutations in cardiac sodium channels (NaV1.5) cause various arrhythmias, such as long QT syndrome and Brugada syndrome. Although dozens of mutations throughout the protein have been reported, there are few reported mutations within a voltage sensor S4 transmembrane segment and few that are homozygous. Here we report analysis of a novel lidocaine-sensitive recessive mutation, p.R1309H, in the NaV1.5 DIII/S4 voltage sensor in a patient with a complex arrhythmia syndrome. We expressed the wild type or mutant NaV1.5 heterologously for analysis with the patch-clamp and voltage clamp fluorometry (VCF) techniques. p.R1309H depolarized the voltage-dependence of activation, hyperpolarized the voltage-dependence of inactivation, and slowed recovery from inactivation, thereby reducing the channel availability at physiologic membrane potentials. Additionally, p.R1309H increased the "late" Na(+) current. The location of the mutation in DIIIS4 prompted testing for a gating pore current. We observed an inward current at hyperpolarizing voltages that likely exacerbates the loss-of-function defects at resting membrane potentials. Lidocaine reduced the gating pore current. The p.R1309H homozygous NaV1.5 mutation conferred both gain-of-function and loss-of-function effects on NaV1.5 channel activity. Reduction of a mutation-induced gating pore current by lidocaine suggested a therapeutic mechanism. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Molten salt reactors: reactor cores

    International Nuclear Information System (INIS)

    1983-01-01

    In this critical analysis of the MSBR I project are examined the problems concerning the reactor core. Advantages of breeding depend essentially upon solutions to technological problems like continuous reprocessing or graphite behavior under neutron irradiation. Graphite deformation, moderator unloading, control rods and core instrumentation require more studies. Neutronics of the core, influence of core geometry and salt composition, fuel evolution, and thermohydraulics are reviewed [fr

  9. Increased SRP reactor power

    International Nuclear Information System (INIS)

    MacAfee, I.M.

    1983-01-01

    Major changes in the current reactor hydraulic systems could be made to achieve a total of about 1500 MW increase of reactor power for P, K, and C reactors. The changes would be to install new, larger heat exchangers in the reactor buildings to increase heat transfer area about 24%, to increase H 2 O flow about 30% per reactor, to increase D 2 O flow 15 to 18% per reactor, and increase reactor blanket gas pressure from 5 psig to 10 psig. The increased reactor power is possible because of reduced inlet temperature of reactor coolant, increased heat removal capacity, and increased operating pressure (larger margin from boiling). The 23% reactor power increase, after adjustment for increased off-line time for reactor reloading, will provide a 15% increase of production from P, K, and C reactors. Restart of L Reactor would increase SRP production 33%

  10. Memory-guided drawing training increases Granger causal influences from the perirhinal cortex to V1 in the blind.

    Science.gov (United States)

    Cacciamani, Laura; Likova, Lora T

    2017-05-01

    The perirhinal cortex (PRC) is a medial temporal lobe structure that has been implicated in not only visual memory in the sighted, but also tactile memory in the blind (Cacciamani & Likova, 2016). It has been proposed that, in the blind, the PRC may contribute to modulation of tactile memory responses that emerge in low-level "visual" area V1 as a result of training-induced cortical reorganization (Likova, 2012, 2015). While some studies in the sighted have indicated that the PRC is indeed structurally and functionally connected to the visual cortex (Clavagnier, Falchier, & Kennedy, 2004; Peterson, Cacciamani, Barense, & Scalf, 2012), the PRC's direct modulation of V1 is unknown-particularly in those who lack the visual input that typically stimulates this region. In the present study, we tested Likova's PRC modulation hypothesis; specifically, we used fMRI to assess the PRC's Granger causal influence on V1 activation in the blind during a tactile memory task. To do so, we trained congenital and acquired blind participants on a unique memory-guided drawing technique previously shown to result in V1 reorganization towards tactile memory representations (Likova, 2012). The tasks (20s each) included: tactile exploration of raised line drawings of faces and objects, tactile memory retrieval via drawing, and a scribble motor/memory control. FMRI before and after a week of the Cognitive-Kinesthetic training on these tasks revealed a significant increase in PRC-to-V1 Granger causality from pre- to post-training during the memory drawing task, but not during the motor/memory control. This increase in causal connectivity indicates that the training strengthened the top-down modulation of visual cortex from the PRC. This is the first study to demonstrate enhanced directed functional connectivity from the PRC to the visual cortex in the blind, implicating the PRC as a potential source of the reorganization towards tactile representations that occurs in V1 in the blind brain

  11. Nuclear research reactors

    International Nuclear Information System (INIS)

    1985-01-01

    It's presented data about nuclear research reactors in the world, retrieved from the Sien (Nuclear and Energetic Information System) data bank. The information are organized in table forms as follows: research reactors by countries; research reactors by type; research reactors by fuel and research reactors by purpose. (E.G.) [pt

  12. Nuclear reactor physics course for reactor operators

    International Nuclear Information System (INIS)

    Baeten, P.

    2006-01-01

    The education and training of nuclear reactor operators is important to guarantee the safe operation of present and future nuclear reactors. Therefore, a course on basic 'Nuclear reactor physics' in the initial and continuous training of reactor operators has proven to be indispensable. In most countries, such training also results from the direct request from the safety authorities to assure the high level of competence of the staff in nuclear reactors. The aim of the basic course on 'Nuclear Reactor Physics for reactor operators' is to provide the reactor operators with a basic understanding of the main concepts relevant to nuclear reactors. Seen the education level of the participants, mathematical derivations are simplified and reduced to a minimum, but not completely eliminated

  13. Nuclear reactor

    International Nuclear Information System (INIS)

    Jolly, R.

    1979-01-01

    The support grid for the fuel rods of a liquid metal cooled fast breeder reactor has a regular hexagonal contour and contains a large number of unit cells arranged honeycomb fashion. The totality of these cells make up a hexagonal shape. The grid contains a number of strips of material, and there is a window in each of three sidewalls staggered by one sidewall. The other sidewalls have embossed protrusions, thus generating a guide lining or guide bead. The windows reduce the rigidity of the areas in the middle between the ends of the cells. (DG) [de

  14. Nuclear reactor

    International Nuclear Information System (INIS)

    Anthony, A.J.; Gruber, E.A.

    1979-01-01

    A nuclear reactor with control rods in channels between fuel assemblies wherein the fuel assemblies incorporate guide rods which protrude outwardly into the control rod channels to prevent the control rods from engaging the fuel elements. The guide rods also extend back into the fuel assembly such that they are relatively rigid members. The guide rods are tied to the fuel assembly end or support plates and serve as structural members which are supported independently of the fuel element. Fuel element spacing and support means may be attached to the guide rods. 9 claims

  15. Upgrading of existing NPPs with 440 and 1000 MW WWER type pressurized water reactors for severe external loading conditions. Proceedings. Working material. V. 1, 2

    Energy Technology Data Exchange (ETDEWEB)

    Godoy, A; Gurpinar, A [eds.; International Atomic Energy Agency, Division of Nuclear Installation Safety, Vienna (Austria)

    1993-07-01

    The Seminar was intended to provide the opportunity for the exchange of updated information concerning the state-of-the-art related to structural safety of the WWER 440 and 1000 MW nuclear power plants operating or under construction in the Russian Federation and several Eastern European countries. Codes and standards, design assumptions, seismic upgrading and requalification activities, recent verification by experimental methods as well as the corresponding reanalysis and reevaluation procedures were included in the scope. Also presented and discussed were the results of recent studies of typical structures and components under seismic loading. The Seminar was divided into five working sessions. Each session consisted of several presentations by invited speakers and extensive discussions. The topic of discussions involved the following: standards used during design phase, input load definitions and criteria, evaluation of as-built conditions and walk down information, site-specific dynamic response of structures based on recent studies and evaluation of results, capacity evaluations of components and systems based on updated acceptance criteria and strengthening concepts, functional qualification of active mechanical and electrical components and systems.

  16. Upgrading of existing NPPs with 440 and 1000 MW WWER type pressurized water reactors for severe external loading conditions. Proceedings. Working material. V. 1, 2

    International Nuclear Information System (INIS)

    Godoy, A.; Gurpinar, A.

    1993-01-01

    The Seminar was intended to provide the opportunity for the exchange of updated information concerning the state-of-the-art related to structural safety of the WWER 440 and 1000 MW nuclear power plants operating or under construction in the Russian Federation and several Eastern European countries. Codes and standards, design assumptions, seismic upgrading and requalification activities, recent verification by experimental methods as well as the corresponding reanalysis and reevaluation procedures were included in the scope. Also presented and discussed were the results of recent studies of typical structures and components under seismic loading. The Seminar was divided into five working sessions. Each session consisted of several presentations by invited speakers and extensive discussions. The topic of discussions involved the following: standards used during design phase, input load definitions and criteria, evaluation of as-built conditions and walk down information, site-specific dynamic response of structures based on recent studies and evaluation of results, capacity evaluations of components and systems based on updated acceptance criteria and strengthening concepts, functional qualification of active mechanical and electrical components and systems

  17. User manual of Visual Balan V. 1.0 Interactive code for water balances and refueling estimation

    International Nuclear Information System (INIS)

    Samper, J.; Huguet, L.; Ares, J.; Garcia, M. A.

    1999-01-01

    This document contains the Users Manual of Visual Balan V1.0, an updated version of Visual Balan V0.0 (Samper et al., 1997). Visual Balan V1.0 performs daily water balances in the soil, the unsaturated zone and the aquifer in a user-friendly environment which facilitates both the input data process and the postprocessing of results. The main inputs of the balance are rainfall and irrigation while the outputs are surface runoff, evapotranspiration, interception, inter flow and groundwater flow. The code evaluates all these components in a sequential manner by starting with rainfall and irrigation, which must be provided by the user, and continuing with interception, surface runoff, evapotranspiration, and potential recharge (water flux crossing the bottom of the soil). This potential recharge is the input to the unsaturated zone where water can flow horizontally as subsurface flow (inter flow) or vertically as percolation into the aquifer. (Author)

  18. Channeling Vision: CaV1.4—A Critical Link in Retinal Signal Transmission

    Directory of Open Access Journals (Sweden)

    D. M. Waldner

    2018-01-01

    Full Text Available Voltage-gated calcium channels (VGCC are key to many biological functions. Entry of Ca2+ into cells is essential for initiating or modulating important processes such as secretion, cell motility, and gene transcription. In the retina and other neural tissues, one of the major roles of Ca2+-entry is to stimulate or regulate exocytosis of synaptic vesicles, without which synaptic transmission is impaired. This review will address the special properties of one L-type VGCC, CaV1.4, with particular emphasis on its role in transmission of visual signals from rod and cone photoreceptors (hereafter called “photoreceptors,” to the exclusion of intrinsically photoreceptive retinal ganglion cells to the second-order retinal neurons, and the pathological effects of mutations in the CACNA1F gene which codes for the pore-forming α1F subunit of CaV1.4.

  19. The impact of nitration on the structure and immunogenicity of the major birch pollen allergen Bet v 1.0101.

    Directory of Open Access Journals (Sweden)

    Chloé Ackaert

    Full Text Available Allergy prevalence has increased in industrialized countries. One contributing factor could be pollution, which can cause nitration of allergens exogenously (in the air or endogenously (in inflamed lung tissue. We investigated the impact of nitration on both the structural and immunological behavior of the major birch pollen allergen Bet v 1.0101 to determine whether nitration might be a factor in the increased incidence of allergy. Bet v 1.0101 was nitrated with tetranitromethane. Immune effects were assessed by measuring the proliferation of specific T-cell lines (TCLs upon stimulation with different concentrations of nitrated and unmodified allergen, and by measurement of cytokine release of monocyte-derived dendritic cells (moDCs and primary DCs (primDCs stimulated with nitrated versus unmodified allergen. HPLC-MS, crystallography, gel electrophoresis, amino acid analysis, size exclusion chromatography and molecular dynamics simulation were performed to characterize structural changes after nitration of the allergen. The proliferation of specific TCLs was higher upon stimulation with the nitrated allergen in comparison to the unmodified allergen. An important structural consequence of nitration was oligomerization. Moreover, analysis of the crystal structure of nitrated Bet v 1.0101 showed that amino acid residue Y83, located in the hydrophobic cavity, was nitrated to 100%. Both moDCs and primDCs showed decreased production of TH1-priming cytokines, thus favoring a TH2 response. These results implicate that nitration of Bet v 1.0101 might be a contributing factor to the observed increase in birch pollen allergy, and emphasize the importance of protein modifications in understanding the molecular basis of allergenicity.

  20. Mechanism of μ-conotoxin PIIIA binding to the voltage-gated Na+ channel NaV1.4.

    Directory of Open Access Journals (Sweden)

    Rong Chen

    Full Text Available Several subtypes of voltage-gated Na+ (NaV channels are important targets for pain management. μ-Conotoxins isolated from venoms of cone snails are potent and specific blockers of different NaV channel isoforms. The inhibitory effect of μ-conotoxins on NaV channels has been examined extensively, but the mechanism of toxin specificity has not been understood in detail. Here the known structure of μ-conotoxin PIIIA and a model of the skeletal muscle channel NaV1.4 are used to elucidate elements that contribute to the structural basis of μ-conotoxin binding and specificity. The model of NaV1.4 is constructed based on the crystal structure of the bacterial NaV channel, NaVAb. Six different binding modes, in which the side chain of each of the basic residues carried by the toxin protrudes into the selectivity filter of NaV1.4, are examined in atomic detail using molecular dynamics simulations with explicit solvent. The dissociation constants (Kd computed for two selected binding modes in which Lys9 or Arg14 from the toxin protrudes into the filter of the channel are within 2 fold; both values in close proximity to those determined from dose response data for the block of NaV currents. To explore the mechanism of PIIIA specificity, a double mutant of NaV1.4 mimicking NaV channels resistant to μ-conotoxins and tetrodotoxin is constructed and the binding of PIIIA to this mutant channel examined. The double mutation causes the affinity of PIIIA to reduce by two orders of magnitude.

  1. The Role of Attention in Figure-Ground Segregation in Areas V1 and V4 of the Visual Cortex

    OpenAIRE

    Poort, Jasper; Raudies, Florian; Wannig, Aurel; Lamme, Victor A.F.; Neumann, Heiko; Roelfsema, Pieter R.

    2012-01-01

    Our visual system segments images into objects and background. Figure-ground segregation relies on the detection of feature discontinuities that signal boundaries between the figures and the background and on a complementary region-filling process that groups together image regions with similar features. The neuronal mechanisms for these processes are not well understood and it is unknown how they depend on visual attention. We measured neuronal activity in V1 and V4 in a task where monkeys e...

  2. High Temperature Creep of an Al-8,5Fe-1,3V-1,7Si Alloy

    Czech Academy of Sciences Publication Activity Database

    Kuchařová, Květa; Zhu, S. J.; Čadek, Josef

    2002-01-01

    Roč. 40, č. 2 (2002), s. 69-84 ISSN 0023-432X R&D Projects: GA AV ČR IBS2041001 Institutional research plan: CEZ:AV0Z2041904 Keywords : Al-8,5Fe 1,3V 1,7Si alloy * creep behavior , true threshold stress Subject RIV: JI - Composite Materials Impact factor: 0.493, year: 2002

  3. Analysis of Location of Laminar-Turbulent Transition on the FX 66-S-196 V1 Airfoil

    Directory of Open Access Journals (Sweden)

    Laurynas Naujokaitis

    2011-04-01

    Full Text Available The transition location on the FX 66‑S‑196 V1 wing section was analyzed with the using interactive program XFOIL of Mark Drela, MIT. Calculated results of transition location were compared with published measurement data from a wind tunnel at Delft University of Technology (Netherlands. The airfoil was analyzed at the Reynolds number Re = 0,5·106 and Re = 1,5·106. Article in Lithuanian

  4. Glycosylation of alpha(2)delta(1) subunit: a sweet talk with Ca(v)1.2 channels

    Czech Academy of Sciences Publication Activity Database

    Lazniewska, Joanna; Weiss, Norbert

    2016-01-01

    Roč. 35, č. 3 (2016), s. 239-242 ISSN 0231-5882 R&D Projects: GA ČR GA15-13556S; GA MŠk 7AMB15FR015 Institutional support: RVO:61388963 Keywords : calcium channel * Ca(v)1.2 channel * ancillary subunit * alpha(2)delta(1) subunit * glycosylation * trafficking Subject RIV: CE - Biochemistry Impact factor: 1.170, year: 2016

  5. Nuclear reactors

    International Nuclear Information System (INIS)

    Prescott, R.F.; George, B.V.; Baglin, C.J.

    1979-01-01

    In a nuclear reactor (e.g. one having coolant down-flow through a core to a hearth below) thermal insulation (e.g. of a floor of the hearth) comprises a layer of bricks and a layer of tiles thereon, with smaller clearances between the tiles than between the bricks but with the bricks being of reduced cross-section immediately adjacent the tiles so as to be surrounded by interconnected passages, of relatively large dimensions, constituting a continuous chamber extending behind the layer of tiles. By this arrangement, lateral coolant flow in the inter-brick clearances is much reduced. The reactor core is preferably formed of hexagonal columns, supported on diamond-shaped plates each supported on a pillar resting on one of the hearth-floor tiles. Each plate has an internal duct, four upper channels connecting the duct with coolant ducts in four core columns supported by the plate, and lower channels connecting the duct to a downwardly-open recess common to three plates, grouped to form a hexagon, at their mutually-adjacent corners. This provides mixing, and temperature-averaging, of coolant from twelve columns

  6. Reactor container

    International Nuclear Information System (INIS)

    Oikawa, Hirohide; Otonari, Jun-ichiro; Tozaki, Yuka.

    1993-01-01

    Partition walls are disposed between a reactor pressure vessel and a suppression chamber to separate a dry well to an upper portion and a lower portion. A communication pipe is disposed to the partition walls. One end of the communication pipe is opened in an upper portion of the dry well at a position higher than a hole disposed to a bent tube of the suppression chamber. When coolants overflow from a depressurization valve by an erroneous operation of an emergency reactor core cooling device, the coolants accumulate in the upper portion of the dry well. When the pipeline is ruptured at the upper portion of the pressure vessel, only the inside of the pressure vessel and the upper portion of the dry well are submerged in water. In this case, the water level of the coolants does not elevate to the opening of the commuication pipe but they flow into the suppression chamber from the hole disposed to the bent tube. Since the coolants do not flow out to the lower portion of the dry well, important equipments such as control rod drives disposed at the lower portion of the dry wall can be prevented from submerging in water. (I.N.)

  7. Reactor monitor

    International Nuclear Information System (INIS)

    Takada, Tamotsu.

    1992-01-01

    The device of the present invention monitors a reactor so that each of the operations for the relocation of fuel assemblies and the withdrawal and the insertion of control rods upon exchange of fuel assemblies and control rods in the reactor. That is, when an operator conducts relocating operation by way of a fuel assembly operation section, the device of the present invention judges whether the operation indication is adequate or not, based on the information of control rod arrangement in a control rod memory section. When the operation indication is wrong, a stop signal is sent to a fuel assembly relocating device. Further, when the operator conducts control rod operation by way of a control rod operation section, the device of the present invention judges in the control rod withdrawal judging section, as to whether the operation indication given by the operator is adequate or not by comparing it with fuel assembly arrangement information. When the operation indication is wrong, a stop signal is sent to control rod drives. With such procedures, increase of nuclear heating upon occurrence of erroneous operation can be prevented. (I.S.)

  8. Nuclear reactors

    International Nuclear Information System (INIS)

    Matheson, J.E.

    1983-01-01

    A nuclear reactor has an upper and a lower grid plate. Protrusions project from the upper grid plate. Fuel assemblies having end fittings fit between the grid plates. An arrangement is provided for accepting axial forces generated during the operation of the nuclear reactor by the flow of the cooling medium and thermal expansion and irradiation-induced growth of the fuel assembly, which comprises rods. Each fuel assembly rests on the lower grid plate and its upper end is elastically supported against the upper grid plate by the above-mentioned arrangement. The arrangement comprises four (for example) torsion springs each having a torsion tube and a torsion bar nested within the torsion tube and connected at one end thereto. The other end of the torsion bar is connected to an associated one of four lever arms. The torsion tube is rigidly connected to the other end fitting and the springs are disposed such that the lever arms are biassed against the protrusions. (author)

  9. Biophysical characterization data of the artificial protein Octarellin V.1 and binding test with its X-ray helpers

    Directory of Open Access Journals (Sweden)

    Maximiliano Figueroa

    2016-09-01

    Full Text Available The artificial protein Octarellin V.1 (http://dx.doi.org/10.1016/j.jsb.2016.05.004 [1] was obtained through a direct evolution process over the de novo designed Octarellin V (http://dx.doi.org/10.1016/S0022-2836(0201206-8 [2]. The protein has been characterized by circular dichroism and fluorescence techniques, in order to obtain data related to its thermo and chemical stability. Moreover, the data for the secondary structure content studied by circular dichroism and infra red techniques is reported for the Octarellin V and V.1. Two crystallization helpers, nanobodies (http://dx.doi.org/10.1038/nprot.2014.039 [3] and αRep (http://dx.doi.org/10.1016/j.jmb.2010.09.048 [4], have been used to create stable complexes. Here we present the data obtained of the binding characterization of the Octarellin V.1 with the crystallization helpers by isothermal titration calorimetry. Keywords: Artificial proteins, Circular dichroism, Crystallization helpers, Infra red spectroscopy, Protein design, Isothermal Titration Calorimetry

  10. Spatial and temporal characteristics of V1 microstimulation during chronic implantation of a microelectrode array in a behaving macaque

    Science.gov (United States)

    Davis, T. S.; Parker, R. A.; House, P. A.; Bagley, E.; Wendelken, S.; Normann, R. A.; Greger, B.

    2012-12-01

    Objective. It has been hypothesized that a vision prosthesis capable of evoking useful visual percepts can be based upon electrically stimulating the primary visual cortex (V1) of a blind human subject via penetrating microelectrode arrays. As a continuation of earlier work, we examined several spatial and temporal characteristics of V1 microstimulation. Approach. An array of 100 penetrating microelectrodes was chronically implanted in V1 of a behaving macaque monkey. Microstimulation thresholds were measured using a two-alternative forced choice detection task. Relative locations of electrically-evoked percepts were measured using a memory saccade-to-target task. Main results. The principal finding was that two years after implantation we were able to evoke behavioural responses to electric stimulation across the spatial extent of the array using groups of contiguous electrodes. Consistent responses to stimulation were evoked at an average threshold current per electrode of 204 ± 49 µA (mean ± std) for groups of four electrodes and 91 ± 25 µA for groups of nine electrodes. Saccades to electrically-evoked percepts using groups of nine electrodes showed that the animal could discriminate spatially distinct percepts with groups having an average separation of 1.6 ± 0.3 mm (mean ± std) in cortex and 1.0° ± 0.2° in visual space. Significance. These results demonstrate chronic perceptual functionality and provide evidence for the feasibility of a cortically-based vision prosthesis for the blind using penetrating microelectrodes.

  11. Elementary properties of CaV1.3 Ca(2+) channels expressed in mouse cochlear inner hair cells.

    Science.gov (United States)

    Zampini, Valeria; Johnson, Stuart L; Franz, Christoph; Lawrence, Neil D; Münkner, Stefan; Engel, Jutta; Knipper, Marlies; Magistretti, Jacopo; Masetto, Sergio; Marcotti, Walter

    2010-01-01

    Mammalian cochlear inner hair cells (IHCs) are specialized to process developmental signals during immature stages and sound stimuli in adult animals. These signals are conveyed onto auditory afferent nerve fibres. Neurotransmitter release at IHC ribbon synapses is controlled by L-type Ca(V)1.3 Ca(2+) channels, the biophysics of which are still unknown in native mammalian cells. We have investigated the localization and elementary properties of Ca(2+) channels in immature mouse IHCs under near-physiological recording conditions. Ca(V)1.3 Ca(2+) channels at the cell pre-synaptic site co-localize with about half of the total number of ribbons present in immature IHCs. These channels activated at about 70 mV, showed a relatively short first latency and weak inactivation, which would allow IHCs to generate and accurately encode spontaneous Ca(2+) action potential activity characteristic of these immature cells. The Ca(V)1.3 Ca(2+) channels showed a very low open probability (about 0.15 at 20 mV: near the peak of an action potential). Comparison of elementary and macroscopic Ca(2+) currents indicated that very few Ca(2+) channels are associated with each docked vesicle at IHC ribbon synapses. Finally, we found that the open probability of Ca(2+) channels, but not their opening time, was voltage dependent. This finding provides a possible correlation between presynaptic Ca(2+) channel properties and the characteristic frequency/amplitude of EPSCs in auditory afferent fibres.

  12. CP determination and tests for CP or P violation by the V1V2 decay mode

    International Nuclear Information System (INIS)

    Nelson, C.A.

    1984-01-01

    A decay mode such as phiphi, UPSILONUPSILON, K/sup asterisk+/K/sup asterisk-/, or D/sup asterisk+/D/sup asterisk-/ can be used to distinguish between a neutral spin-0 technipion and a neutral spin-0 Higgs particle. By this generalization of phiphi parity test, the CP eigenvalue γ/sub C/P can be determined for an X particle of any spin J which decays CP invariantly into VV, or VV-bar, where each vector meson either decays into two spin-0 bosons, or is ω. The absence in a VV, or VV-bar, decay channel of sin2phi and sinphi terms in the azimuthal distribution is due to CP invariance and/or P invariance. For a V 1 V 2 decay channel without a V 1 bold-arrow-left-rightV 2 exchange property, and in a mode like K/sup asterisk+/K /sup asterisk0/, such terms would imply that P is violated. For a V 1 V 2 mode such as phiω where each vector meson is its own antiparticle, such terms would imply that both P and CP are violated; when CP invariance holds, the γ/sub C/P(-)/sup J/ eigenvalue of X can be determined provided certain amplitudes do not accidentally vanish

  13. NaV1.6a is required for normal activation of motor circuits normally excited by tactile stimulation

    Science.gov (United States)

    Low, Sean E.; Zhou, Weibin; Choong, Xinling; Saint-Amant, Louis; Sprague, Shawn M.; Hirata, Hiromi; Cui, Wilson W.; Hume, Richard I.; Kuwada, John Y.

    2010-01-01

    A screen for zebrafish motor mutants identified two non-complementing alleles of a recessive mutation that were named non-active (navmi89 and navmi130). nav embryos displayed diminished spontaneous and touch-evoked escape behaviors during the first three days of development. Genetic mapping identified the gene encoding NaV1.6a (scn8aa) as a potential candidate for nav. Subsequent cloning of scn8aa from the two alleles of nav uncovered two missense mutations in NaV1.6a that eliminated channel activity when assayed heterologously. Furthermore the injection of RNA encoding wild type scn8aa rescued the nav mutant phenotype indicating that scn8aa was the causative gene of nav. In vivo electrophysiological analysis of the touch-evoked escape circuit indicated that voltage-dependent inward current was decreased in mechanosensory neurons in mutants, but they were able to fire action potentials. Furthermore tactile stimulation of mutants activated some neurons downstream of mechanosensory neurons but failed to activate the swim locomotor circuit in accord with the behavioral response of initial escape contractions but no swimming. Thus mutant mechanosensory neurons appeared to respond to tactile stimulation but failed to initiate swimming. Interestingly fictive swimming could be initiated pharmacologically suggesting that a swim circuit was present in mutants. These results suggested that NaV1.6a was required for touch-induced activation of the swim locomotor network. PMID:20225246

  14. Early Posttransplant Isolated v1 Lesion Does Not Need to Be Treated and Does Not Lead to Increased Fibrosis

    Directory of Open Access Journals (Sweden)

    Irfan Moinuddin

    2016-01-01

    Full Text Available Acute vascular rejection (AVR is characterized by intimal arteritis in addition to tubulitis and interstitial inflammation. It is associated with a poorer prognosis compared to tubulointerstitial rejection (AIR and AVR is associated with a higher rate of graft loss than AIR. The prognosis and treatment of arteritis without tubulitis and interstitial inflammation (isolated v1 lesion are still controversial. We report a case of a patient who had a biopsy of the kidney allograft for evaluation of slow graft function. The biopsy revealed an isolated v1 lesion. However, we chose not to augment immunosuppression. The patient’s kidney allograft function improved over time with close monitoring. Repeat biopsy a year later showed no evidence of endothelialitis and relatively unchanged fibrosis and no other abnormalities. Although it is suggested that most cases of isolated v1 lesions will respond to corticosteroids or T cell depleting therapies, some cases will improve with conservative management. Further studies are needed to determine which cases could be managed conservatively.

  15. Reactor core fuel management

    International Nuclear Information System (INIS)

    Silvennoinen, P.

    1976-01-01

    The subject is covered in chapters, entitled: concepts of reactor physics; neutron diffusion; core heat transfer; reactivity; reactor operation; variables of core management; computer code modules; alternative reactor concepts; methods of optimization; general system aspects. (U.K.)

  16. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T [Huntington Beach, CA; Sahimi, Muhammad [Altadena, CA; Fayyaz-Najafi, Babak [Richmond, CA; Harale, Aadesh [Los Angeles, CA; Park, Byoung-Gi [Yeosu, KR; Liu, Paul K. T. [Lafayette Hill, PA

    2011-03-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  17. Reactor outage schedule (tentative)

    Energy Technology Data Exchange (ETDEWEB)

    Walton, R.P.

    1969-11-01

    This single page document is the November 1, 1969 reactor refueling outage schedule for the Hanford Production Reactor. It also contains data on the amounts and types of fuels to be loaded and relocated in the production reactor.

  18. Reactor outage schedule (tentative)

    Energy Technology Data Exchange (ETDEWEB)

    Walton, R.P.

    1969-10-01

    This single page document is the October 1, 1969 reactor refueling outage schedule for the Hanford Production Reactor. It also contains data on the amounts and types of fuels to be loaded and relocated in the Production Reactor.

  19. Reactor outage schedule (tentative)

    Energy Technology Data Exchange (ETDEWEB)

    Walton, R.P.

    1969-10-15

    This single page document is the October 15, 1969 reactor refueling outage schedule for the Hanford Production Reactor. It also contains data on the amounts and types of fuels to be loaded and relocated in the Production Reactor.

  20. Reactor outage schedule (tentative)

    Energy Technology Data Exchange (ETDEWEB)

    Walton, R.P.

    1969-09-15

    This single page document is the September 15, 1969 reactor refueling outage schedule for the Hanford Production Reactor. It also contains data on the amounts and types of fuels to be loaded and relocated in the Production Reactor.

  1. Reactor outage schedule (tentative)

    Energy Technology Data Exchange (ETDEWEB)

    Walton, R.P.

    1969-12-15

    This single page document is the December 16, 1969 reactor refueling outage schedule for the Hanford Production Reactor. It also contains data on the amounts and types of fuels to be loaded and relocated in the Production reactor.

  2. Reactor outage schedule (tentative)

    Energy Technology Data Exchange (ETDEWEB)

    Walton, R.P.

    1969-12-01

    This single page document is the December 1, 1969 reactor refueling outage schedule for the Hanford Production Reactor. It also contains data on the amounts and types of fuels to be loaded and relocated in the Production reactor.

  3. Reactor theory and power reactors. 1. Calculational methods for reactors. 2. Reactor kinetics

    International Nuclear Information System (INIS)

    Henry, A.F.

    1980-01-01

    Various methods for calculation of neutron flux in power reactors are discussed. Some mathematical models used to describe transients in nuclear reactors and techniques for the reactor kinetics' relevant equations solution are also presented

  4. MgATP hydrolysis destabilizes the interaction between subunit H and yeast V1-ATPase, highlighting H's role in V-ATPase regulation by reversible disassembly.

    Science.gov (United States)

    Sharma, Stuti; Oot, Rebecca A; Wilkens, Stephan

    2018-05-12

    Vacuolar H+-ATPases (V-ATPases; V1Vo-ATPases) are rotary motor proton pumps that acidify intracellular compartments and in some tissues, the extracellular space. V-ATPase is regulated by reversible disassembly into autoinhibited V1-ATPase and Vo proton channel sectors. An important player in V-ATPase regulation is subunit H, which binds at the interface of V1 and Vo. H is required for MgATPase activity in holo V-ATPase, but also for stabilizing the MgADP inhibited state in membrane detached V1. However, how H fulfills these two functions is poorly understood. To characterize the H-V1 interaction and its role in reversible disassembly, we determined binding affinities of full length H and its N-terminal domain (HNT) for an isolated heterodimer of subunits E and G (EG), the N-terminal domain of subunit a (aNT), and V1 lacking subunit H (V1ΔH). Using isothermal titration calorimetry (ITC) and biolayer interferometry (BLI), we show that HNT binds EG with moderate affinity, that full length H binds aNT weakly, and that both H and HNT bind V1ΔH with high affinity. We also found that only one molecule of HNT binds V1ΔH with high affinity, suggesting conformational asymmetry of the three EG heterodimers in V1ΔH. Moreover, MgATP hydrolysis-driven conformational changes in V1 destabilized the interaction of H, or HNT, with V1ΔH, suggesting an interplay between MgADP inhibition and subunit H. Our observation that H binding is affected by MgATP hydrolysis in V1 points to H's role in the mechanism of reversible disassembly. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

  5. The CEA research reactors

    International Nuclear Information System (INIS)

    Schwartz, J.P.

    1993-01-01

    Two main research reactors, specifically designed, PEGASE reactor and Laue-Langevin high flux reactor, are presented. The PEGASE reactor was designed at the end of the 50s for the study of the gas cooled reactor fuel element behaviour under irradiation; the HFR reactor, was designed in the late 60s to serve as a high yield and high level neutron source. Historical backgrounds, core and fuel characteristics and design, flux characteristics, etc., are presented. 5 figs

  6. Atomic reactor thermal engineering

    International Nuclear Information System (INIS)

    Kim, Gwang Ryong

    1983-02-01

    This book starts the introduction of atomic reactor thermal engineering including atomic reaction, chemical reaction, nuclear reaction neutron energy and soon. It explains heat transfer, heat production in the atomic reactor, heat transfer of fuel element in atomic reactor, heat transfer and flow of cooler, thermal design of atomic reactor, design of thermodynamics of atomic reactor and various. This deals with the basic knowledge of thermal engineering for atomic reactor.

  7. Report of the ASSET (Assessment of Safety Significant Events Team) follow-up mission to the Bohunice (units 1-2) nuclear power plant in Slovakia 5-9 July 1993. Root cause analysis of operational events with a view to enhancing the prevention of accidents

    International Nuclear Information System (INIS)

    1993-01-01

    This Report of the IAEA Assessment of Safety Significant Events Team (ASSET) presents the results of the team's review of the status of implementation of the recommendations made by the 1988 ASSET mission to Bohunice nuclear power plant in Slovakia, and of progress made by plant management in prevention of incidents. The findings, conclusions and suggestions presented herein reflect the views of the ASSET experts. They are provided for consideration by the responsible Slovakian authorities. The ASSET team's views presented in this report are based on review of the documentation made available and on the discussions with plant staff. The report includes the official response of the operating and regulatory organizations of Slovakia to the ASSET findings and conclusions. Figs, tabs

  8. Nuclear reactor types

    International Nuclear Information System (INIS)

    Jones, P.M.S.

    1987-01-01

    The characteristics of different reactor types designed to exploit controlled fission reactions are explained. Reactors vary from low power research devices to high power devices especially designed to produce heat, either for direct use or to produce steam to drive turbines to generate electricity or propel ships. A general outline of basic reactors (thermal and fast) is given and then the different designs considered. The first are gas cooled, including the Magnox reactors (a list of UK Magnox stations and reactor performance is given), advanced gas cooled reactors (a list of UK AGRs is given) and the high temperature reactor. Light water cooled reactors (pressurized water [PWR] and boiling water [BWR] reactors) are considered next. Heavy water reactors are explained and listed. The pressurized heavy water reactors (including CANDU type reactors), boiling light water, steam generating heavy water reactors and gas cooled heavy water reactors all come into this category. Fast reactors (liquid metal fast breeder reactors and gas cooled fast reactors) and then water-cooled graphite-moderated reactors (RBMK) (the type at Chernobyl-4) are discussed. (U.K.)

  9. Reactor safety

    International Nuclear Information System (INIS)

    Meneley, D.A.

    The people of Ontario have begun to receive the benefits of a low cost, assured supply of electrical energy from CANDU nuclear stations. This indigenous energy source also has excellent safety characteristics. Safety has been one of the central themes of the CANDU development program from its very beginning. A great deal of work has been done to establish that public risks are small. However, safety design criteria are now undergoing extensive review, with a real prospect of more stringent requirements being applied in the future. Considering the newness of the technology it is not surprising that a consensus does not yet exist; this makes it imperative to discuss the issues. It is time to examine the policies and practice of reactor safety management in Canada to decide whether or not further restrictions are justified in the light of current knowledge

  10. Nuclear reactor

    International Nuclear Information System (INIS)

    Schabert, H.P.; Weber, R.; Bauer, A.

    1975-01-01

    The refuelling of a PWR power reactor of about 1,200 MWe is performed by a transport pipe in the containment leading from an external to an internal fuel pit. A wagon to transport the fuel elements can go from a vertical loading position to an also vertical deloading position in the inner fuel pit via guide rollers. The necessary horizontal movement is effected by means of a cable line through the transport pipe which is inclined at least 10 0 . Gravity thus helps in the movement to the deloading position. The cable line with winch is fastened outside the containment. Swivelling devices tip the wagon from the horizontal to the vertical position or vice versa. Loading and deloading are done laterally. (TK/LH) [de

  11. Nuclear reactor

    International Nuclear Information System (INIS)

    Schweiger, F.; Glahe, E.

    1976-01-01

    In a nuclear reactor of the kind which is charged with spherical reaction elements and in which control rods are arranged to be thrust directly into the charge, each control rod has at least one screw thread on its external surface so that as the rod is thrust into the charge it is caused to rotate and thus make penetration easier. The length of each control rod may have two distinct portions, a latter portion which carries a screw thread and a lead-in portion which is shorter than the latter portion and which may carry a thread of greater pitch than that on the latter portion or may have a number of axially extending ribs instead of a thread

  12. Reactor container

    International Nuclear Information System (INIS)

    Furukawa, Hideyasu; Oyamada, Osamu; Uozumi, Hiroto.

    1976-01-01

    Purpose: To provide a container for a reactor provided with a pressure suppressing chamber pool which can prevent bubble vibrating load, particularly negative pressure generated at the time of starting to release exhaust from a main steam escape-safety valve from being transmitted to a lower liner plate of the container. Constitution: This arrangement is characterized in that a safety valve exhaust pool for main steam escape, in which a pressure suppressing chamber pool is separated and intercepted from pool water in the pressure suppressing chamber pool, a safety valve exhaust pipe is open into said safety valve exhaust pool, and an isolator member, which isolates the bottom liner plate in the pressure suppressing chamber pool from the pool water, is disposed on the bottom of the safety valve exhaust pool. (Nakamura, S.)

  13. Nuclear reactors

    International Nuclear Information System (INIS)

    Prescott, R.F.

    1976-01-01

    In the system described the fuel elements are arranged vertically in groups and are supported in such a manner as to tend to tilt them towards the center of the respective group, the fuel elements being urged laterally into abutment with one another. The elements have interlocking bearing pads, whereby lateral movement of adjacent elements is resisted; this improves the stability of the reactor core during refuelling operations. Fuel elements may comprise clusters of parallel fuel pins enclosed in a wrapper of hexagonal cross section, with bearing pads in the form of spline-like ribs located on each side of the wrapper and extending parallel to the longitudinal axis of the fuel element, being interlockable with ribs on pads of adjacent fuel elements. The arrangement is applicable to a reactor core in which fuel elements and control rod guide tubes are arranged in modules each of which comprises a cluster of at least three fuel elements, one of which is rigidly supported whilst the others are resiliently tilted towards the center of the cluster so as to lean on the rigidly supported element. It is also applicable to modules comprising a cluster of six fuel elements, each resiliently tilted towards a central void to form a circular arch. The modules may include additional fuel elements located outside the clusters and also resiliently tilted towards the central voids, the latter being used to accommodate control rod guide tubes. The need for separate structural members to act as leaning posts is thus avoided. Such structural members are liable to irradiation embrittlement, that could lead to core failure. (U.K.)

  14. 75 FR 54627 - ICLUS v1.3 User's Manual: ArcGIS Tools and Datasets for Modeling U.S. Housing Density Growth

    Science.gov (United States)

    2010-09-08

    ...'s guide titled, ``ICLUS v1.3 User's Manual: ArcGIS Tools and Datasets for Modeling U.S. Housing...: ``ICLUS v1.3 User's Manual: ArcGIS Tools and Datasets for Modeling U.S. Housing Density Growth'' and the... final document title, ``ICLUS v1.3 User's Manual: ArcGIS Tools and Datasets for Modeling U.S. Housing...

  15. Nuclear reactor neutron shielding

    Science.gov (United States)

    Speaker, Daniel P; Neeley, Gary W; Inman, James B

    2017-09-12

    A nuclear reactor includes a reactor pressure vessel and a nuclear reactor core comprising fissile material disposed in a lower portion of the reactor pressure vessel. The lower portion of the reactor pressure vessel is disposed in a reactor cavity. An annular neutron stop is located at an elevation above the uppermost elevation of the nuclear reactor core. The annular neutron stop comprises neutron absorbing material filling an annular gap between the reactor pressure vessel and the wall of the reactor cavity. The annular neutron stop may comprise an outer neutron stop ring attached to the wall of the reactor cavity, and an inner neutron stop ring attached to the reactor pressure vessel. An excore instrument guide tube penetrates through the annular neutron stop, and a neutron plug comprising neutron absorbing material is disposed in the tube at the penetration through the neutron stop.

  16. Verification of the AZNHEX code v.1.4 with MCNP6 for different reference cases; Verificacion del codigo AZNHEX v.1.4 con MCNP6 para diferentes casos de referencia

    Energy Technology Data Exchange (ETDEWEB)

    Galicia A, J.; Francois L, J. L.; Bastida O, G. E. [UNAM, Facultad de Ingenieria, Departamento de Sistemas Energeticos, Ciudad Universitaria, Circuito Exterior s/n, 04510 Ciudad de Mexico (Mexico); Del Valle G, E., E-mail: jgaliciaa87@gmail.com [IPN, Escuela Superior de Fisica y Matematicas, Av. IPN s/n, 07738 Ciudad de Mexico (Mexico)

    2017-09-15

    The codes that make up the AZTLAN platform (AZTHECA, AZTRAN, AZKIND and AZNHEX) are currently in the testing phase simulating a variety of nuclear reactor assemblies and cores to compare and validate the results obtained for a particular case, with codes globally used in the nuclear area such as CASMO, Serpent and MCNP. The objective of this work is to continue improving the future versions of the codes of the AZTLAN platform so that accurate and reliable results can be obtained for the user. To test the current version of the AZNHEX code, 3 cases were taken into account, the first being the simulation of a VVER-440 reactor assembly; for the second case, the assembly of a fast reactor cooled with helium was simulated and for the third case it was decided to take up the case of the core of a fast reactor cooled with sodium, this because the previous versions of AZNHEX did not show adequate results and, in addition, they presented a considerable amount of limitations. The comparison and validation of the results (neutron multiplication factor, radial power, radial flow, axial power) for these three cases were made using the code MCNP6. The results obtained show that this version of AZNHEX produces values of the neutron multiplication factor and the neutron and power flow distributions very close to those of MCNP6. (Author)

  17. IgE and allergen-specific immunotherapy-induced IgG4 recognize similar epitopes of Bet v 1, the major allergen of birch pollen.

    Science.gov (United States)

    Groh, N; von Loetzen, C S; Subbarayal, B; Möbs, C; Vogel, L; Hoffmann, A; Fötisch, K; Koutsouridou, A; Randow, S; Völker, E; Seutter von Loetzen, A; Rösch, P; Vieths, S; Pfützner, W; Bohle, B; Schiller, D

    2017-05-01

    Allergen-specific immunotherapy (AIT) with birch pollen generates Bet v 1-specific immunoglobulin (Ig)G 4 which blocks IgE-mediated hypersensitivity mechanisms. Whether IgG 4 specific for Bet v 1a competes with IgE for identical epitopes or whether novel epitope specificities of IgG 4 antibodies are developed is under debate. We sought to analyze the epitope specificities of IgE and IgG 4 antibodies from sera of patients who received AIT. 15 sera of patients (13/15 received AIT) with Bet v 1a-specific IgE and IgG 4 were analyzed. The structural arrangements of recombinant (r)Bet v 1a and rBet v 1a _11x , modified in five potential epitopes, were analyzed by circular dichroism and nuclear magnetic resonance spectroscopy. IgE binding to Bet v 1 was assessed by ELISA and mediator release assays. Competitive binding of monoclonal antibodies specific for Bet v 1a and serum IgE/IgG 4 to rBet v 1a and serum antibody binding to a non-allergenic Bet v 1-type model protein presenting an individual epitope for IgE was analyzed in ELISA and western blot. rBet v 1a _11x had a Bet v 1a - similar secondary and tertiary structure. Monomeric dispersion of rBet v 1a _11x was concentration and buffer-dependent. Up to 1500-fold increase in the EC 50 for IgE-mediated mediator release induced by rBet v 1a _11x was determined. The reduction of IgE and IgG 4 binding to rBet v 1a _11x was comparable in 67% (10/15) of sera. Bet v 1a-specific monoclonal antibodies inhibited binding of serum IgE and IgG 4 to 66.1% and 64.9%, respectively. Serum IgE and IgG 4 bound specifically to an individual epitope presented by our model protein in 33% (5/15) of sera. Patients receiving AIT develop Bet v 1a-specific IgG 4 which competes with IgE for partly identical or largely overlapping epitopes. The similarities of epitopes for IgE and IgG 4 might stimulate the development of epitope-specific diagnostics and therapeutics. © 2016 John Wiley & Sons Ltd.

  18. Dissecting Reactor Antineutrino Flux Calculations

    Science.gov (United States)

    Sonzogni, A. A.; McCutchan, E. A.; Hayes, A. C.

    2017-09-01

    Current predictions for the antineutrino yield and spectra from a nuclear reactor rely on the experimental electron spectra from 235U, 239Pu, 241Pu and a numerical method to convert these aggregate electron spectra into their corresponding antineutrino ones. In the present work we investigate quantitatively some of the basic assumptions and approximations used in the conversion method, studying first the compatibility between two recent approaches for calculating electron and antineutrino spectra. We then explore different possibilities for the disagreement between the measured Daya Bay and the Huber-Mueller antineutrino spectra, including the 238U contribution as well as the effective charge and the allowed shape assumption used in the conversion method. We observe that including a shape correction of about +6 % MeV-1 in conversion calculations can better describe the Daya Bay spectrum. Because of a lack of experimental data, this correction cannot be ruled out, concluding that in order to confirm the existence of the reactor neutrino anomaly, or even quantify it, precisely measured electron spectra for about 50 relevant fission products are needed. With the advent of new rare ion facilities, the measurement of shape factors for these nuclides, for many of which precise beta intensity data from TAGS experiments already exist, would be highly desirable.

  19. The Contributions of the on and off Gain Difference to the Contextual Effect in Macaque Monkey V1

    Directory of Open Access Journals (Sweden)

    Kuo-Sheng Lee

    2012-10-01

    Full Text Available In macaque monkey V1, the response amplitudes of ON and OFF sub-regions of simple receptive fields are about equal for cells in the input layer 4c, but the OFF responses tend to be greater than the ON responses for layer-2/3 cells. This OFF-over-ON bias is evident when receptive fields are mapped with sparse noise (a series of dark or bright squares shown in different space and time but is weaker with Hartleys (gratings shown briefly at different orientations and spatial frequencies. One possible mechanism for the receptive-field mismatch in layer 2/3 of V1 is the difference between ON and OFF response gains caused by different degrees of sparseness between Hartleys and sparse noise. Here we manipulated the relative strength of ON and OFF sparse-noise responses until the receptive field similarity (RFS, quantified as the pixel-by-pixel correlation between two maps between sparse-noise and Hartley maps reached the maximum. On average, the relative strength of ON/OFF responses in sparse-noise maps should be increased to approximately two times of their origins in order to match closely their Hartley compartments for layer-2/3 neurons (1.93±0.19; mean±S.E.M.. The sole change in response gain largely increased the RFS between Hartley and sparse-noise maps (on average the RFS increases from 0.35 to 0.58, and it could account for approximately 81% of the overall differences between the two maps. In summary, the difference in ON and OFF gains under different visual stimulations is one critical mechanism underlying the contextual effect in the superficial layer of V1.

  20. Elementary properties of CaV1.3 Ca2+ channels expressed in mouse cochlear inner hair cells

    Science.gov (United States)

    Zampini, Valeria; Johnson, Stuart L; Franz, Christoph; Lawrence, Neil D; Münkner, Stefan; Engel, Jutta; Knipper, Marlies; Magistretti, Jacopo; Masetto, Sergio; Marcotti, Walter

    2010-01-01

    Mammalian cochlear inner hair cells (IHCs) are specialized to process developmental signals during immature stages and sound stimuli in adult animals. These signals are conveyed onto auditory afferent nerve fibres. Neurotransmitter release at IHC ribbon synapses is controlled by L-type CaV1.3 Ca2+ channels, the biophysics of which are still unknown in native mammalian cells. We have investigated the localization and elementary properties of Ca2+ channels in immature mouse IHCs under near-physiological recording conditions. CaV1.3 Ca2+ channels at the cell pre-synaptic site co-localize with about half of the total number of ribbons present in immature IHCs. These channels activated at about −70 mV, showed a relatively short first latency and weak inactivation, which would allow IHCs to generate and accurately encode spontaneous Ca2+ action potential activity characteristic of these immature cells. The CaV1.3 Ca2+ channels showed a very low open probability (about 0.15 at −20 mV: near the peak of an action potential). Comparison of elementary and macroscopic Ca2+ currents indicated that very few Ca2+ channels are associated with each docked vesicle at IHC ribbon synapses. Finally, we found that the open probability of Ca2+ channels, but not their opening time, was voltage dependent. This finding provides a possible correlation between presynaptic Ca2+ channel properties and the characteristic frequency/amplitude of EPSCs in auditory afferent fibres. PMID:19917569

  1. Synthesis and magnetic properties of PrFe11V1-xTix and their nitrides

    International Nuclear Information System (INIS)

    Tang, S.L.; Wang, B.W.; Zhang, C.; Jin, X.M.; Zhang, S.Y.; Du, Y.W.

    1997-01-01

    We have succeeded in synthesizing PrFe 11 V 1-x Ti x (x=0.2 1) compound and their nitrides with the ThMn 12 -type structure. The phase formation and magnetic properties have been investigated by x-ray diffraction, differential thermometric analysis, and magnetic measurement. The stable temperature range of the 1-12 phase for PrFe 11 V 1-x Ti x alloys has been determined as a function of Ti content. PrFe 11 V compounds with the ThMn 12 -type structure do not exist and PrFe 11 Ti compounds with the TnMn 12 -type structure are obtained by annealing in a narrow temperature range between 1303 and 1383 K. Furthermore, 1-12 phase with the ThMn 12 -type structure can be obtained at lower temperature and wider temperature range with decreasing Ti content x (0.2≤x≤1). PrFe 11 V 1-x Ti x N y with x=0.2 1 has a T c of about 730 785 K, B a larger than 8 T and M s in the range 144 148 emu/g. These intrinsic magnetic properties are highly favorable for permanent magnet applications. As a preliminary, an intrinsic coercivity of 5.4 kOe is obtained for PrFe 11 V 0.5 Ti 0.5 N y at room temperature by using mechanical alloying technique. copyright 1997 American Institute of Physics

  2. X-ray Photoelectron Spectroscopy study of CaV1-xMoxO3-δ

    Science.gov (United States)

    Belyakov, S. A.; Kuznetsov, M. V.; Shkerin, S. N.

    2018-06-01

    An investigation was carried out on perovskite-based derivatives of CaV1-xMoxO3-δ using X-ray Photoelectron Spectroscopy (XPS). According to the XRD pattern, the area of homogeneity covers the region from x = 0 to x = 0.6. Wide XPS-peaks of Ca, V, Mo and O are observed, signalling that elements are presented in multiple states. A model for explaining the large chemical shifts of XPS peaks due to different charging effects on different parts of the sample surface is proposed.

  3. FBG_SiMul V1.0: Fibre Bragg grating signal simulation tool for finite element method models

    Directory of Open Access Journals (Sweden)

    G. Pereira

    2016-01-01

    Full Text Available FBG_SiMul V1.0 is a tool to study and design the implementation of fibre Bragg grating (FBG sensors solutions in any arbitrary loaded structure or application. The software removes the need for a fibre optic expert user and makes the sensor response of a structural health monitoring solution using FBG sensors more simple and fast. The software uses a modified T-Matrix method to simulate the FBG reflected spectrum based on the stress and strain from a finite element method model. The article describes the theory and algorithm implementation, followed by an empirical validation.

  4. Thermal-deformation effect of welding on A 1 reactor pressure vessel weld joints properties and state of stress

    International Nuclear Information System (INIS)

    Becka, J.; Kupka, I.

    1976-01-01

    The methods are compared of electroslag welding and of arc welding with a view to their possible application in welding the Bohunice A-1 reactor pressure vessel. Considered are the thermal deformation effects of welding on the physical properties and the stress present in welded joints. For testing, plates were used having the dimensions of 1100x2300x200 mm and rings with 4820 mm outer diameter, 1800 mm height and 170 mm thickness made of steel CSN 413O30 modified with Ni, Al+Ti. The deformation effect of welding on the residual surface and triaxial stress, the specific stored energy, the initiation temperature of brittle crack and the critical size of the initiation defect corresponding to the thermal deformation effect of welding were determined. It was found that for electroslag welding, there is a low probability of crack formation in the joints, a low level of residual stress and a low level of specific stored energy in a relatively wide joint zone. For arc welding there is a considerable probability of defect formation in the vicinity of the sharp boundary of the joint, a high level of the triaxial state of stress in the tensile region, and a high level of specific stored energy concentrated in the narrow zone of weld joints. The recommended thermal process is given for welding pressure vessels made of the CSN 413030 steel modified with Ni, Al+Ti, and 150 to 200 mm in thickness. (J.P.)

  5. FBR type reactor

    International Nuclear Information System (INIS)

    Kimura, Kimitaka; Fukuie, Ken; Iijima, Tooru; Shimpo, Masakazu.

    1994-01-01

    In an FBR type reactor for exchanging fuels by pulling up reactor core upper mechanisms, a connection mechanism is disposed for connecting the top of the reactor core and the lower end of the reactor core upper mechanisms. In addition, a cylindrical body is disposed surrounding the reactor core upper mechanisms, and a support member is disposed to the cylindrical body for supporting an intermediate portion of the reactor core upper mechanisms. Then, the lower end of the reactor core upper mechanisms is connected to the top of the reactor core. Same displacements are caused to both of them upon occurrence of earthquakes and, as a result, it is possible to eliminate mutual horizontal displacement between a control rod guide hole of the reactor core upper mechanisms and a control rod insertion hole of the reactor core. In addition, since the intermediate portion of the reactor core upper mechanisms is supported by the support member disposed to the cylindrical body surrounding the reactor core upper mechanisms, deformation caused to the lower end of the reactor core upper mechanisms is reduced, so that the mutual horizontal displacement with respect to the control rod insertion hole of the reactor core can be reduced. As a result, performance of control rod insertion upon occurrence of the earthquakes is improved, so that reactor shutdown is conducted more reliably to improve reactor safety. (N.H.)

  6. The prototype fast reactor

    International Nuclear Information System (INIS)

    Broomfield, A.M.

    1985-01-01

    The paper concerns the Prototype Fast Reactor (PFR), which is a liquid metal cooled fast reactor power station, situated at Dounreay, Scotland. The principal design features of a Fast Reactor and the PFR are given, along with key points of operating history, and health and safety features. The role of the PFR in the development programme for commercial reactors is discussed. (U.K.)

  7. Department of reactor technology

    International Nuclear Information System (INIS)

    1980-01-01

    The activities of the Department of Reactor Technology at Risoe during 1979 are described. The work is presented in five chapters: Reactor Engineering, Reactor Physics and Dynamics, Heat Transfer and Hydraulics, The DR 1 Reactor, and Non-Nuclear Activities. A list of the staff and of publications is included. (author)

  8. NCSU Reactor Sharing Program

    International Nuclear Information System (INIS)

    Perez, P.B.

    1993-01-01

    The Nuclear Reactor Program at North Carolina State University provides the PULSTAR Research Reactor and associated facilities to eligible institutions with support, in part, from the Department of Energy Reactor Sharing Program. Participation in the NCSU Reactor Sharing Program continues to increase steadily with visitors ranging from advance high school physics and chemistry students to Ph.D. level research from neighboring universities

  9. Reactor safety method

    International Nuclear Information System (INIS)

    Vachon, L.J.

    1980-01-01

    This invention relates to safety means for preventing a gas cooled nuclear reactor from attaining criticality prior to start up in the event the reactor core is immersed in hydrogenous liquid. This is accomplished by coating the inside surface of the reactor coolant channels with a neutral absorbing material that will vaporize at the reactor's operating temperature

  10. Localisation of SCN10A gene product Na(v)1.8 and novel pain-related ion channels in human heart.

    Science.gov (United States)

    Facer, Paul; Punjabi, Prakash P; Abrari, Andleeb; Kaba, Riyaz A; Severs, Nicholas J; Chambers, John; Kooner, Jaspal S; Anand, Praveen

    2011-01-01

    We have shown that the gene SCN10A encoding the sodium channel Na(v)1.8 is a susceptibility factor for heart block and serious ventricular arrhythmia. Since Na(v)1.8 is known to be present in nerve fibres that mediate pain, it may be related to both cardiac pain and dysrhythmia. The localisation of Na(v)1.8 and other key nociceptive ion channels, including Na(v)1.7, Na(v)1.9, capsaicin receptor TRPV1, and purinergic receptor P2X(3), have not been reported in human heart. The aim of this study was to determine the distribution of Na(v)1.8, related sodium and other sensory channels in human cardiac tissue, and correlate their density with sympathetic nerves, regenerating nerves (GAP-43), and vascularity. Human heart atrial appendage tissues (n = 13) were collected during surgery for valve disease. Tissues were investigated by immunohistology using specific antibodies to Na(v)1.8 and other markers. Na(v)1.8 immunoreactivity was detected in nerve fibres and fascicles in the myocardium, often closely associated with small capillaries. Na(v)1.8 nerve fibres per mm(2) correlated significantly with vascular markers. Na(v)1.8-immunoreactivity was present also in cardiomyocytes with a similar distribution pattern to that seen with connexins, the specialised gap junction proteins of myocardial intercalated discs. Na(v)1.5-immunoreactivity was detected in cardiomyocytes but not in nerve fibres. Na(v)1.7, Na(v)1.9, TRPV1, P2X(3)/P2X(2), and GAP43 positive nerve fibres were relatively sparse, whereas sympathetic innervation and connexin43 were abundant. We conclude that sodium channel Na(v)1.8 is present in sensory nerves and cardiomyocytes of human heart. Na(v)1.8 and other pain channels provide new targets for the understanding and treatment of cardiac pain and dysrhythmia.

  11. Physics of nuclear reactors

    International Nuclear Information System (INIS)

    Baeten, Peter

    2006-01-01

    This course gives an introduction to Nuclear Reactor Physics. The first chapter explains the most important parameters and concepts in nuclear reactor physics such as fission, cross sections and the effective multiplication factor. Further on, in the second chapter, the flux distributions in a stationary reactor are derived from the diffusion equation. Reactor kinetics, reactor control and reactor dynamics (feedback effects) are described in the following three chapters. The course concludes with a short description of the different types of existing and future reactors. (author)

  12. Reactor core and initially loaded reactor core of nuclear reactor

    International Nuclear Information System (INIS)

    Koyama, Jun-ichi; Aoyama, Motoo.

    1989-01-01

    In BWR type reactors, improvement for the reactor shutdown margin is an important characteristic condition togehter with power distribution flattening . However, in the reactor core at high burnup degree, the reactor shutdown margin is different depending on the radial position of the reactor core. That is , the reactor shutdown margin is smaller in the outer peripheral region than in the central region of the reactor core. In view of the above, the reactor core is divided radially into a central region and as outer region. The amount of fissionable material of first fuel assemblies newly loaded in the outer region is made less than the amount of the fissionable material of second fuel assemblies newly loaded in the central region, to thereby improve the reactor shutdown margin in the outer region. Further, the ratio between the amount of the fissionable material in the upper region and that of the fissionable material in the lower portion of the first fuel assemblies is made smaller than the ratio between the amount of the fissionable material in the upper region and that of the fissionable material in the lower region of the second fuel assemblies, to thereby obtain a sufficient thermal margin in the central region. (K.M.)

  13. Nuclear reactors. Introduction

    International Nuclear Information System (INIS)

    Boiron, P.

    1997-01-01

    This paper is an introduction to the 'nuclear reactors' volume of the Engineers Techniques collection. It gives a general presentation of the different articles of the volume which deal with: the physical basis (neutron physics and ionizing radiations-matter interactions, neutron moderation and diffusion), the basic concepts and functioning of nuclear reactors (possible fuel-moderator-coolant-structure combinations, research and materials testing reactors, reactors theory and neutron characteristics, neutron calculations for reactor cores, thermo-hydraulics, fluid-structure interactions and thermomechanical behaviour of fuels in PWRs and fast breeder reactors, thermal and mechanical effects on reactors structure), the industrial reactors (light water, pressurized water, boiling water, graphite moderated, fast breeder, high temperature and heavy water reactors), and the technology of PWRs (conceiving and building rules, nuclear parks and safety, reactor components and site selection). (J.S.)

  14. Corrosion technology. V. 1

    International Nuclear Information System (INIS)

    Khan, I.H.

    1989-01-01

    This book has been produced for dissemination of information on corrosion technology, corrosion hazards and its control. Chapter one of this book presents an overall view of the subject and chapter 2-5 deals with electrochemical basics, types of corrosion, pourbaix diagrams and form of corrosion. The author explains polarization/kinetics of corrosion, passivity, aqueous corrosion and corrosion testing and monitoring in 6-11 chapters. The author hopes it will provide incentive to all those interested in the corrosion technology. (A.B.)

  15. AFA's annals. V. 1

    International Nuclear Information System (INIS)

    1990-01-01

    The meeting of the Argentine Physics Association (AFA) held in 1989 is intended to expose the scientific works of its associates as well as of specially invited scientists. It also aims to diffuse the advances of physical science and its applications in the Argentine scientific community. The papers included in this work are representative of physical research in the country. The subjects of research were: mathematical methods in physics; classical and quantum physics, mechanics and fields; statistical physics and thermodynamics; nuclear physics; atomic physics, elementary particles and fields; optics and optical spectroscopy; fluid dynamics; plasma physics and electric discharges; condensed matter; applied physics: instruments, physical chemistry, biophysics, medical physics and biomedical engineering [es

  16. Thermonuclear reactor

    International Nuclear Information System (INIS)

    Yasutomi, Yoshiyuki; Nakagawa, Moroo; Sawai, Yuichi; Chiba, Akio; Suzuki, Yasutaka.

    1997-01-01

    Silicon composited with reinforcing metals is used for a divertor cooling substrate having an effect as a cooling tube to provide a silicon base composite material having increased electric resistance and toughness. The blending ratio of reinforcing materials in the form of granules, whiskers or long fibers is controlled in order to control heat conductivity, electric resistivity and mechanical performances. The divertor cooling substrate comprising the silicon base composite material is integrated with a plasma facing material. The production method therefor includes ordinary metal matrix composite forming methods such as powder metallurgy, melting penetration method, high pressure solidification casting method, centrifugal casting method and vacuum casting method. Since the cooling plate is constituted with the light metal and highly electric resistant metal base composite material, sharing force due to eddy current can be reduced, and radiation exposure can be minimized. Accordingly, a cooling structure for a thermonuclear reactor effective for the improvement of environmental problems caused by waste disposal can be attained. (N.H.)

  17. Nuclear reactor

    International Nuclear Information System (INIS)

    Irion, L.; Tautz, J.; Ulrych, G.

    1976-01-01

    This additional patent complements the arrangement of non-return valves to prevent loss of cooling water on fracture of external tubes in the main coolant circuit (according to PS 24 24 427.7) by ensuring that the easily movable valves only operate in case of a fault, but do not flutter in operation, because the direction of flow is not the same at each location where they are installed. The remedy for this undesirable effect consists of allocating 1 non-return valve unit with 5 to 10 valves to each (of several) ducts for the cooling water intake. These units are installed in the annular space between the reactor vessel and the pressure vessel below the inlet of the ducts. Due to flow guidance surfaces in the same space, the incoming cooling water is deflected downwards and as the guiding surfaces are closed at the sides, must pass parallel to the valves of the non-return valve unit. On fracture of the external cooling water inlet pipe concerned, all valves of this unit close due to reversal of flow on the outlet side. (TK) [de

  18. Nuclear reactors

    International Nuclear Information System (INIS)

    Pearson, K.G.

    1977-01-01

    Reference is made to auxiliary means of cooling the nuclear fuel clusters used in light or heavy water cooled nuclear reactors. One method is to provide one or more spray cooling tubes. From holes in the side walls of those tubes coolant water may be sprayed laterally into the cluster against the rods. The flow of main coolant may thus be supplemented or even replaced by the auxiliary coolant. A difficulty, however, is that only those fuel rods close to a spray cooling tube can readily be reached by the auxiliary coolant. In the arrangement described, where the fuel rods are spaced apart by transverse grids, at least one of the interspaces between the grids is provided with an axially extending auxiliary coolant conduit having lateral holes through which an auxiliary coolant is sprayed into the cluster. A deflector is provided that extends from a transverse grid into a position in front of the holes and deflects auxiliary coolant on to parts of the fuel rods otherwise inaccessible to the auxiliary coolant. The construction of the deflector is described. (U.K.)

  19. Irradiation Embrittlement Monitoring Programs of RPV's in the Slovak Republic NPP's

    International Nuclear Information System (INIS)

    Kupca, Ludovik

    2006-01-01

    Four types of surveillance programs were (are) realized in Slovak NPP's: 'Standard Surveillance Specimen Program' (SSSP) was finished in Jaslovske Bohunice V-2 Nuclear Power Plant (NPP) Units 3 and 4, 'Extended Surveillance Specimen Program' (ESSP), was prepared for Jaslovske Bohunice NPP V-2 with aim to validate the SSSP results, For the Mochovce NPP Unit 1 and 2 was prepared completely new surveillance program 'Modern Surveillance Specimen Program' (MSSP), based on the philosophy that the results of MSSP must be available during all NPP service life, For the Bohunice V-1 NPP was finished 'New Surveillance Specimen Program' (NSSP) coordinated by IAEA, which gave arguments for prolongation of service life these units for minimum 20 years, New Advanced Surveillance Specimen Program (ASSP) for Bohunice V-2 NPP (units 3 and 4) and Mochovce NPP (units 1, 2) is approved now. ASSP is dealing with the irradiation embrittlement of heat affected zone (HAZ) and RPV's austenitic cladding, which were not evaluated till this time in surveillance programs. SSSP started in 1979 and was finished in 1990. ESSP program started in 1995 and will be finished in 2007, was prepared with aim of: increasing of neutron fluence measurement accuracy, substantial improvement the irradiation temperature measurement, fixed orientation of samples to the centre of the reactor core, minimum differences of neutron dose for all the Charpy-V notch and COD specimens, the dose rate effect evaluation. In the year 1996 was started the new surveillance specimen program for the Mochovce RPV's unit-1 and 2, based on the fundamental postulate - to provide the irradiation embrittlement monitoring till the end of units operation. The 'New Surveillance Specimen Program' (NSSP) prepared in the year 1999 for the Bohunice V-1 NPP was finished in the year 2004. Main goal of this program was to evaluate the weld material properties degradation due to the irradiation and recovery efficiency by annealing too. The

  20. Nuclear reactor coolant channels

    International Nuclear Information System (INIS)

    Macbeth, R.V.

    1978-01-01

    A nuclear reactor coolant channel is described that is suitable for sub-cooled reactors as in pressurised water reactors as well as for bulk boiling, as in boiling water reactors and steam generating nuclear reactors. The arrangement aims to improve heat transfer between the fuel elements and the coolant. Full constructional details are given. See also other similar patents by the author. (U.K.)

  1. Fast breeder reactors

    International Nuclear Information System (INIS)

    Heinzel, V.

    1975-01-01

    The author gives a survey of 'fast breeder reactors'. In detail the process of breeding, the reasons for the development of fast breeders, the possible breeder reactors, the design criteria, fuels, cladding, coolant, and safety aspects are reported on. Design data of some experimental reactors already in operation are summarized in stabular form. 300 MWe Prototype-Reactors SNR-300 and PFR are explained in detail and data of KWU helium-cooled fast breeder reactors are given. (HR) [de

  2. Structural basis for diverse N-glycan recognition by HIV-1-neutralizing V1-V2-directed antibody PG16

    Energy Technology Data Exchange (ETDEWEB)

    Pancera, Marie; Shahzad-ul-Hussan, Syed; Doria-Rose, Nicole A.; McLellan, Jason S.; Bailer, Robert T.; Dai, Kaifan; Loesgen, Sandra; Louder, Mark K.; Staupe, Ryan P.; Yang, Yongping; Zhang, Baoshan; Parks, Robert; Eudailey, Joshua; Lloyd, Krissey E.; Blinn, Julie; Alam, S. Munir; Haynes, Barton F.; Amin, Mohammed N.; Wang, Lai-Xi; Burton, Dennis R.; Koff, Wayne C.; Nabel, Gary J.; Mascola, John R.; Bewley, Carole A; Kwong, Peter D. [NIH; (Scripps); (Duke); (Maryland-MED); (IAVI)

    2013-08-05

    HIV-1 uses a diverse N-linked-glycan shield to evade recognition by antibody. Select human antibodies, such as the clonally related PG9 and PG16, recognize glycopeptide epitopes in the HIV-1 V1–V2 region and penetrate this shield, but their ability to accommodate diverse glycans is unclear. Here we report the structure of antibody PG16 bound to a scaffolded V1–V2, showing an epitope comprising both high mannose–type and complex-type N-linked glycans. We combined structure, NMR and mutagenesis analyses to characterize glycan recognition by PG9 and PG16. Three PG16-specific residues, arginine, serine and histidine (RSH), were critical for binding sialic acid on complex-type glycans, and introduction of these residues into PG9 produced a chimeric antibody with enhanced HIV-1 neutralization. Although HIV-1–glycan diversity facilitates evasion, antibody somatic diversity can overcome this and can provide clues to guide the design of modified antibodies with enhanced neutralization.

  3. Physical interaction of junctophilin and the CaV1.1 C terminus is crucial for skeletal muscle contraction.

    Science.gov (United States)

    Nakada, Tsutomu; Kashihara, Toshihide; Komatsu, Masatoshi; Kojima, Katsuhiko; Takeshita, Toshikazu; Yamada, Mitsuhiko

    2018-04-24

    Close physical association of Ca V 1.1 L-type calcium channels (LTCCs) at the sarcolemmal junctional membrane (JM) with ryanodine receptors (RyRs) of the sarcoplasmic reticulum (SR) is crucial for excitation-contraction coupling (ECC) in skeletal muscle. However, the molecular mechanism underlying the JM targeting of LTCCs is unexplored. Junctophilin 1 (JP1) and JP2 stabilize the JM by bridging the sarcolemmal and SR membranes. Here, we examined the roles of JPs in localization and function of LTCCs. Knockdown of JP1 or JP2 in cultured myotubes inhibited LTCC clustering at the JM and suppressed evoked Ca 2+ transients without disrupting JM structure. Coimmunoprecipitation and GST pull-down assays demonstrated that JPs physically interacted with 12-aa residues in the proximal C terminus of the Ca V 1.1. A JP1 mutant lacking the C terminus including the transmembrane domain (JP1ΔCT) interacted with the sarcolemmal/T-tubule membrane but not the SR membrane. Expression of this mutant in adult mouse muscles in vivo exerted a dominant-negative effect on endogenous JPs, impairing LTCC-RyR coupling at triads without disrupting JM morphology, and substantially reducing Ca 2+ transients without affecting SR Ca 2+ content. Moreover, the contractile force of the JP1ΔCT-expressed muscle was dramatically reduced compared with the control. Taken together, JPs recruit LTCCs to the JM through physical interaction and ensure robust ECC at triads in skeletal muscle.

  4. Na(v)1.8 channelopathy in mutant mice deficient for myelin protein zero is detrimental to motor axons

    DEFF Research Database (Denmark)

    Moldovan, Mihai; Alvarez Herrero, Susana; Pinchenko, Volodymyr

    2011-01-01

    Myelin protein zero mutations were found to produce Charcot-Marie-Tooth disease phenotypes with various degrees of myelin impairment and axonal loss, ranging from the mild 'demyelinating' adult form to severe and early onset forms. Protein zero deficient homozygous mice ( ) show a severe and prog......Myelin protein zero mutations were found to produce Charcot-Marie-Tooth disease phenotypes with various degrees of myelin impairment and axonal loss, ranging from the mild 'demyelinating' adult form to severe and early onset forms. Protein zero deficient homozygous mice ( ) show a severe...... and progressive dysmyelinating neuropathy from birth with compromised myelin compaction, hypomyelination and distal axonal degeneration. A previous study using immunofluorescence showed that motor nerves deficient of myelin protein zero upregulate the Na(V)1.8 voltage gated sodium channel isoform, which...... is normally present only in restricted populations of sensory axons. The aim of this study was to investigate the function of motor axons in protein zero-deficient mice with particular emphasis on ectopic Na(V)1.8 voltage gated sodium channel. We combined 'threshold tracking' excitability studies...

  5. Texture Segregation Causes Early Figure Enhancement and Later Ground Suppression in Areas V1 and V4 of Visual Cortex.

    Science.gov (United States)

    Poort, Jasper; Self, Matthew W; van Vugt, Bram; Malkki, Hemi; Roelfsema, Pieter R

    2016-10-01

    Segregation of images into figures and background is fundamental for visual perception. Cortical neurons respond more strongly to figural image elements than to background elements, but the mechanisms of figure-ground modulation (FGM) are only partially understood. It is unclear whether FGM in early and mid-level visual cortex is caused by an enhanced response to the figure, a suppressed response to the background, or both.We studied neuronal activity in areas V1 and V4 in monkeys performing a texture segregation task. We compared texture-defined figures with homogeneous textures and found an early enhancement of the figure representation, and a later suppression of the background. Across neurons, the strength of figure enhancement was independent of the strength of background suppression.We also examined activity in the different V1 layers. Both figure enhancement and ground suppression were strongest in superficial and deep layers and weaker in layer 4. The current-source density profiles suggested that figure enhancement was caused by stronger synaptic inputs in feedback-recipient layers 1, 2, and 5 and ground suppression by weaker inputs in these layers, suggesting an important role for feedback connections from higher level areas. These results provide new insights into the mechanisms for figure-ground organization. © The Author 2016. Published by Oxford University Press.

  6. Areas V1 and V2 show microsaccade-related 3-4-Hz covariation in gamma power and frequency.

    Science.gov (United States)

    Lowet, E; Roberts, M J; Bosman, C A; Fries, P; De Weerd, P

    2016-05-01

    Neuronal gamma-band synchronization (25-80 Hz) in visual cortex appears sustained and stable during prolonged visual stimulation when investigated with conventional averages across trials. However, recent studies in macaque visual cortex have used single-trial analyses to show that both power and frequency of gamma oscillations exhibit substantial moment-by-moment variation. This has raised the question of whether these apparently random variations might limit the functional role of gamma-band synchronization for neural processing. Here, we studied the moment-by-moment variation in gamma oscillation power and frequency, as well as inter-areal gamma synchronization, by simultaneously recording local field potentials in V1 and V2 of two macaque monkeys. We additionally analyzed electrocorticographic V1 data from a third monkey. Our analyses confirm that gamma-band synchronization is not stationary and sustained but undergoes moment-by-moment variations in power and frequency. However, those variations are neither random and nor a possible obstacle to neural communication. Instead, the gamma power and frequency variations are highly structured, shared between areas and shaped by a microsaccade-related 3-4-Hz theta rhythm. Our findings provide experimental support for the suggestion that cross-frequency coupling might structure and facilitate the information flow between brain regions. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  7. The role of attention in figure-ground segregation in areas V1 and V4 of the visual cortex.

    Science.gov (United States)

    Poort, Jasper; Raudies, Florian; Wannig, Aurel; Lamme, Victor A F; Neumann, Heiko; Roelfsema, Pieter R

    2012-07-12

    Our visual system segments images into objects and background. Figure-ground segregation relies on the detection of feature discontinuities that signal boundaries between the figures and the background and on a complementary region-filling process that groups together image regions with similar features. The neuronal mechanisms for these processes are not well understood and it is unknown how they depend on visual attention. We measured neuronal activity in V1 and V4 in a task where monkeys either made an eye movement to texture-defined figures or ignored them. V1 activity predicted the timing and the direction of the saccade if the figures were task relevant. We found that boundary detection is an early process that depends little on attention, whereas region filling occurs later and is facilitated by visual attention, which acts in an object-based manner. Our findings are explained by a model with local, bottom-up computations for boundary detection and feedback processing for region filling. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Vasotocin neurons and septal V1a-like receptors potently modulate songbird flocking and responses to novelty.

    Science.gov (United States)

    Kelly, Aubrey M; Kingsbury, Marcy A; Hoffbuhr, Kristin; Schrock, Sara E; Waxman, Brandon; Kabelik, David; Thompson, Richmond R; Goodson, James L

    2011-06-01

    Previous comparisons of territorial and gregarious finches (family Estrildidae) suggest the hypothesis that arginine vasotocin (VT) neurons in the medial bed nucleus of the stria terminalis (BSTm) and V(1a)-like receptors in the lateral septum (LS) promote flocking behavior. Consistent with this hypothesis, we now show that intraseptal infusions of a V(1a) antagonist in male zebra finches (Taeniopygia guttata) reduce gregariousness (preference for a group of 10 versus 2 conspecific males), but have no effect on the amount of time that subjects spend in close proximity to other birds ("contact time"). The antagonist also produces a profound increase in anxiety-like behavior, as exhibited by an increased latency to feed in a novelty-suppressed feeding test. Bilateral knockdown of VT production in the BSTm using LNA-modified antisense oligonucleotides likewise produces increases in anxiety-like behavior and a potent reduction in gregariousness, relative to subjects receiving scrambled oligonucleotides. The antisense oligonucleotides also produced a modest increase in contact time, irrespective of group size. Together, these combined experiments provide clear evidence that endogenous VT promotes preferences for larger flock sizes, and does so in a manner that is coupled to general anxiolysis. Given that homologous peptide circuitry of the BSTm-LS is found across all tetrapod vertebrate classes, these findings may be predictive for other highly gregarious species. Published by Elsevier Inc.

  9. Repeated functional convergent effects of NaV1.7 on acid insensitivity in hibernating mammals.

    Science.gov (United States)

    Liu, Zhen; Wang, Wei; Zhang, Tong-Zuo; Li, Gong-Hua; He, Kai; Huang, Jing-Fei; Jiang, Xue-Long; Murphy, Robert W; Shi, Peng

    2014-02-07

    Hibernating mammals need to be insensitive to acid in order to cope with conditions of high CO2; however, the molecular basis of acid tolerance remains largely unknown. The African naked mole-rat (Heterocephalus glaber) and hibernating mammals share similar environments and physiological features. In the naked mole-rat, acid insensitivity has been shown to be conferred by the functional motif of the sodium ion channel NaV1.7. There is now an opportunity to evaluate acid insensitivity in other taxa. In this study, we tested for functional convergence of NaV1.7 in 71 species of mammals, including 22 species that hibernate. Our analyses revealed a functional convergence of amino acid sequences, which occurred at least six times independently in mammals that hibernate. Evolutionary analyses determined that the convergence results from both parallel and divergent evolution of residues in the functional motif. Our findings not only identify the functional molecules responsible for acid insensitivity in hibernating mammals, but also open new avenues to elucidate the molecular underpinnings of acid insensitivity in mammals.

  10. Response evaluation criteria for solid tumours in dogs (v1.0): a Veterinary Cooperative Oncology Group (VCOG) consensus document.

    Science.gov (United States)

    Nguyen, S M; Thamm, D H; Vail, D M; London, C A

    2015-09-01

    In veterinary medical oncology, there is currently no standardized protocol for assessing response to therapy in solid tumours. The lack of such a formalized guideline makes it challenging to critically compare outcome measures across various treatment protocols. The Veterinary Cooperative Oncology Group (VCOG) membership consensus document presented here is based on the recommendations of a subcommittee of American College of Veterinary Internal Medicine (ACVIM) board-certified veterinary oncologists. This consensus paper has used the human response evaluation criteria in solid tumours (RECIST v1.1) as a framework to establish standard procedures for response assessment in canine solid tumours that is meant to be easy to use, repeatable and applicable across a variety of clinical trial structures in veterinary oncology. It is hoped that this new canine RECIST (cRECIST v1.0) will be adopted within the veterinary oncology community and thereby facilitate the comparison of current and future treatment protocols used for companion animals with cancer. © 2013 Blackwell Publishing Ltd.

  11. Crystallization and preliminary X-ray analysis of birch-pollen allergen Bet v 1 in complex with a murine monoclonal IgG Fab' fragment

    DEFF Research Database (Denmark)

    Spangfort, M D; Mirza, Osman Asghar; Gajhede, M

    1999-01-01

    of the clinical symptoms of allergy. In order to study the structural basis of allergen-antibody interaction, a complex between the major birch-pollen allergen Bet v 1 and a Fab' fragment isolated from the murine monoclonal Bet v 1 antibody BV16 has been crystallized. Complex crystals belong to space group P1...

  12. Distal C terminus of CaV1.2 channels plays a crucial role in the neural differentiation of dental pulp stem cells.

    Directory of Open Access Journals (Sweden)

    Jianping Ge

    Full Text Available L-type voltage-dependent CaV1.2 channels play an important role in the maintenance of intracellular calcium homeostasis, and influence multiple cellular processes. C-terminal cleavage of CaV1.2 channels was reported in several types of excitable cells, but its expression and possible roles in non-excitable cells is still not clear. The aim of this study was to determine whether distal C-terminal fragment of CaV1.2 channels is present in rat dental pulp stem cells and its possible role in the neural differentiation of rat dental pulp stem cells. We generated stable CaV1.2 knockdown cells via short hairpin RNA (shRNA. Rat dental pulp stem cells with deleted distal C-terminal of CaV1.2 channels lost the potential of differentiation to neural cells. Re-expression of distal C-terminal of CaV1.2 rescued the effect of knocking down the endogenous CaV1.2 on the neural differentiation of rat dental pulp stem cells, indicating that the distal C-terminal of CaV1.2 is required for neural differentiation of rat dental pulp stem cells. These results provide new insights into the role of voltage-gated Ca(2+ channels in stem cells during differentiation.

  13. Selepressin, a novel selective vasopressin V1A agonist, is an effective substitute for norepinephrine in a phase IIa randomized, placebo-controlled trial in septic shock patients

    DEFF Research Database (Denmark)

    Russell, James A; Vincent, Jean-Louis; Kjølbye, Anne Louise

    2017-01-01

    BACKGROUND: Vasopressin is widely used for vasopressor support in septic shock patients, but experimental evidence suggests that selective V1A agonists are superior. The initial pharmacodynamic effects, pharmacokinetics, and safety of selepressin, a novel V1A-selective vasopressin analogue, was e...

  14. The L-Type Voltage-Gated Calcium Channel Ca [subscript V] 1.2 Mediates Fear Extinction and Modulates Synaptic Tone in the Lateral Amygdala

    Science.gov (United States)

    Temme, Stephanie J.; Murphy, Geoffrey G.

    2017-01-01

    L-type voltage-gated calcium channels (LVGCCs) have been implicated in both the formation and the reduction of fear through Pavlovian fear conditioning and extinction. Despite the implication of LVGCCs in fear learning and extinction, studies of the individual LVGCC subtypes, Ca[subscript V]1.2 and Ca[subscript V] 1.3, using transgenic mice have…

  15. Experience with quality of training of personnel in start-up, operation and maintenance of nuclear power plants

    International Nuclear Information System (INIS)

    Ziman, V.; Alaxin, E.

    1983-01-01

    The theoretical education of personnel takes place in the branch training centre in Jaslovske Bohunice and in the concern training centre of the Slovak Power Plants. Practical training takes place in the Bohunice V-1 power plant. Selected specialists are trained in the training centre of the Novo Voronezh nuclear power plant, at the Paks nuclear plant and in the training centre of the Tusimice power plant. The recruitment, selection, schooling, practical training and placement of personnel and their assignment to posts is done in such a manner as to make sure that the complexly trained personnel is available 6 months to 3 years prior to the physical start-up of the nuclear power plant. The training of university graduates for the post of reactor operator takes 18 months or more. Trained personnel attend in-service training courses in form of complementary courses whose content includes such problems as the elimination of typified possible accidents, on the basis of the analysis of all failures which occurred in the previous period. The rising quality of personnel training at the Bohunice V-1 nuclear power plant is reflected in the decreasing number of failures caused by the human factor and in the increased availability of the power units. (M.D.)

  16. Reactor Physics Training

    International Nuclear Information System (INIS)

    Baeten, P.

    2007-01-01

    University courses in nuclear reactor physics at the universities consist of a theoretical description of the physics and technology of nuclear reactors. In order to demonstrate the basic concepts in reactor physics, training exercises in nuclear reactor installations are also desirable. Since the number of reactor facilities is however strongly decreasing in Europe, it becomes difficult to offer to students a means for demonstrating the basic concepts in reactor physics by performing training exercises in nuclear installations. Universities do not generally possess the capabilities for performing training exercises. Therefore, SCK-CEN offers universities the possibility to perform (on a commercial basis) training exercises at its infrastructure consisting of two research reactors (BR1 and VENUS). Besides the organisation of training exercises in the framework of university courses, SCK-CEN also organizes theoretical courses in reactor physics for the education and training of nuclear reactor operators. It is indeed a very important subject to guarantee the safe operation of present and future nuclear reactors. In this framework, an understanding of the fundamental principles of nuclear reactor physics is also necessary for reactor operators. Therefore, the organisation of a basic Nuclear reactor physics course at the level of reactor operators in the initial and continuous training of reactor operators has proven to be indispensable. In most countries, such training also results from the direct request from the safety authorities to assure the high level of competence of the staff in nuclear reactors. The objectives this activity are: (1) to provide training and education activities in reactor physics for university students and (2) to organise courses in nuclear reactor physics for reactor operators

  17. Voltage-gated potassium channel (K(v) 1) autoantibodies in patients with chagasic gut dysmotility and distribution of K(v) 1 channels in human enteric neuromusculature (autoantibodies in GI dysmotility).

    Science.gov (United States)

    Hubball, A W; Lang, B; Souza, M A N; Curran, O D; Martin, J E; Knowles, C H

    2012-08-01

    Autoantibodies directed against specific neuronal antigens are found in a significant number of patients with gastrointestinal neuromuscular diseases (GINMDs) secondary to neoplasia. This study examined the presence of antineuronal antibodies in idiopathic GINMD and GINMD secondary to South American Trypanosomiasis. The GI distribution of voltage-gated potassium channels (VGKCs) was also investigated. Seventy-three patients were included in the study with diagnoses of primary achalasia, enteric dysmotility, chronic intestinal pseudo-obstruction, esophageal or colonic dysmotility secondary to Chagas' disease. Sera were screened for specific antibodies to glutamic acid decarboxylase, voltage-gated calcium channels (VGCCs; P/Q subtype), nicotinic acetylcholine receptors (nAChRs; α3 subtype), and voltage-gated potassium channels (VGKCs, K(V) 1 subtype) using validated immunoprecipitation assays. The distribution of six VGKC subunits (K(V) 1.1-1.6), including those known to be antigenic targets of anti-VGKC antibodies was immunohistochemically investigated in all main human GI tract regions. Three patients (14%) with chagasic GI dysmotility were found to have positive anti-VGKC antibody titers. No antibodies were detected in patients with idiopathic GINMD. The VGKCs were found in enteric neurons at every level of the gut in unique yet overlapping distributions. The VGKC expression in GI smooth muscle was found to be limited to the esophagus. A small proportion of patients with GI dysfunction secondary to Chagas' disease have antibodies against VGKCs. The presence of these channels in the human enteric nervous system may have pathological relevance to the growing number of GINMDs with which anti-VGKC antibodies have been associated. © 2012 Blackwell Publishing Ltd.

  18. Projections to early visual areas V1 and V2 in the calcarine fissure from parietal association areas in the macaque.

    Directory of Open Access Journals (Sweden)

    Elena eBorra

    2011-06-01

    Full Text Available Non-extrastriate projections to area V1 in monkeys, now demonstrated by several anatomical studies, are potential substrates of physiologically documented multisensory effects in primary sensory areas. The full network of projections among association and primary areas, however, is likely to be complex and is still only partially understood. In the present report, we used the anterograde tracer biotinylated dextran amine to investigate projections to areas V1 and V2 from subdivisions of the parietal association cortex in macaque. Parietal cortex was chosen to allow comparisons between projections from this higher association area and from other previously reported areas. In addition, we were interested in further elucidating pathways to areas V1 and V2 from parietal areas, as potentially contributing to attention and active vision. Of eight cases, three brains had projections only to area V2, and the five others projected to both areas V1 and V2. Terminations in area V1 were sparse. These were located in supragranular layers I, II, upper III; occasionally in IVB; and in layer VI. Terminations in V2 were denser, and slightly more prevalent in the supragranular layers. For both areas, terminations were in the calcarine region, corresponding to the representation of the peripheral visual field. By reconstructions of single axons, we demonstrated that four of nine axons had collaterals, either to V1 and V2 (n=1 or to area V1 and a ventral area likely to be TEO (n=3. In area V1, axons extended divergently in layer VI as well as layer I. Overall, these and previous results suggest a nested connectivity architecture, consisting of multiple direct and indirect recurrent projections from association areas to area V1. Terminations in area V1 are not abundant, but could be potentiated by the network of indirect connections.

  19. CaV1.3 L-type Ca2+ channels modulate depression-like behaviour in mice independent of deaf phenotype.

    Science.gov (United States)

    Busquet, Perrine; Nguyen, Ngoc Khoi; Schmid, Eduard; Tanimoto, Naoyuki; Seeliger, Mathias W; Ben-Yosef, Tamar; Mizuno, Fengxia; Akopian, Abram; Striessnig, Jörg; Singewald, Nicolas

    2010-05-01

    Mounting evidence suggests that voltage-gated L-type Ca2+ channels can modulate affective behaviour. We therefore explored the role of CaV1.3 L-type Ca2+ channels in depression- and anxiety-like behaviours using CaV1.3-deficient mice (CaV1.3-/-). We showed that CaV1.3-/- mice displayed less immobility in the forced swim test as well as in the tail suspension test, indicating an antidepressant-like phenotype. Locomotor activity in the home cage or a novel open-field test was not influenced. In the elevated plus maze (EPM), CaV1.3-/- mice entered the open arms more frequently and spent more time there indicating an anxiolytic-like phenotype which was, however, not supported in the stress-induced hyperthermia test. By performing parallel experiments in Claudin 14 knockout mice (Cldn14-/-), which like CaV1.3-/- mice are congenitally deaf, an influence of deafness on the antidepressant-like phenotype could be ruled out. On the other hand, a similar EPM behaviour indicative of an anxiolytic phenotype was also found in the Cldn14-/- animals. Using electroretinography and visual behavioural tasks we demonstrated that at least in mice, CaV1.3 channels do not significantly contribute to visual function. However, marked morphological changes were revealed in synaptic ribbons in the outer plexiform layer of CaV1.3-/- retinas by immunohistochemistry suggesting a possible role of this channel type in structural plasticity at the ribbon synapse. Taken together, our findings indicate that CaV1.3 L-type Ca2+ channels modulate depression-like behaviour but are not essential for visual function. The findings raise the possibility that selective modulation of CaV1.3 channels could be a promising new therapeutic concept for the treatment of mood disorders.

  20. Age and sex differences in oxytocin and vasopressin V1a receptor binding densities in the rat brain: focus on the social decision-making network.

    Science.gov (United States)

    Smith, Caroline J W; Poehlmann, Max L; Li, Sara; Ratnaseelan, Aarane M; Bredewold, Remco; Veenema, Alexa H

    2017-03-01

    Oxytocin (OT) and vasopressin (AVP) regulate various social behaviors via activation of the OT receptor (OTR) and the AVP V1a receptor (V1aR) in the brain. Social behavior often differs across development and between the sexes, yet our understanding of age and sex differences in brain OTR and V1aR binding remains incomplete. Here, we provide an extensive analysis of OTR and V1aR binding density throughout the brain in juvenile and adult male and female rats, with a focus on regions within the social decision-making network. OTR and V1aR binding density were higher in juveniles than in adults in regions associated with reward and socio-spatial memory and higher in adults than in juveniles in key regions of the social decision-making network and in cortical regions. We discuss possible implications of these shifts in OTR and V1aR binding density for the age-specific regulation of social behavior. Furthermore, sex differences in OTR and V1aR binding density were less numerous than age differences. The direction of these sex differences was region-specific for OTR but consistently higher in females than in males for V1aR. Finally, almost all sex differences in OTR and V1aR binding density were already present in juveniles and occurred in regions with denser binding in adults compared to juveniles. Possible implications of these sex differences for the sex-specific regulation of behavior, as well potential underlying mechanisms, are discussed. Overall, these findings provide an important framework for testing age- and sex-specific roles of OTR and V1aR in the regulation of social behavior.