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Sample records for ra-3 reactor boron

  1. A Small-Animal Irradiation Facility for Neutron Capture Therapy Research at the RA-3 Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Emiliano Pozzi; David W. Nigg; Marcelo Miller; Silvia I. Thorp; Amanda E. Schwint; Elisa M. Heber; Veronica A. Trivillin; Leandro Zarza; Guillermo Estryk

    2007-11-01

    The National Atomic Energy Commission of Argentina (CNEA) has constructed a thermal neutron source for use in Boron Neutron Capture Therapy (BNCT) applications at the RA-3 research reactor facility located in Buenos Aires. The Idaho National Laboratory (INL) and CNEA have jointly conducted some initial neutronic characterization measurements for one particular configuration of this source. The RA-3 reactor (Figure 1) is an open pool type reactor, with 20% enriched uranium plate-type fuel and light water coolant. A graphite thermal column is situated on one side of the reactor as shown. A tunnel penetrating the graphite structure enables the insertion of samples while the reactor is in normal operation. Samples up to 14 cm height and 15 cm width are accommodated.

  2. Toward a clinical application of ex situ boron neutron capture therapy for lung tumors at the RA-3 reactor in Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Farías, R. O.; Trivillin, V. A.; Portu, A. M.; Schwint, A. E.; González, S. J., E-mail: srgonzal@cnea.gov.ar [Comisión Nacional de Energía Atómica (CNEA), San Martín 1650, Argentina and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires 1033 (Argentina); Garabalino, M. A.; Monti Hughes, A.; Pozzi, E. C. C.; Thorp, S. I.; Curotto, P.; Miller, M. E.; Santa Cruz, G. A.; Saint Martin, G. [Comisión Nacional de Energía Atómica (CNEA), San Martín 1650 (Argentina); Ferraris, S.; Santa María, J.; Rovati, O.; Lange, F. [CIDME, Universidad Maimónides, Buenos Aires 1405 (Argentina); Bortolussi, S. [Istituto Nazionale di Fisica Nucleare, Sezione di Pavia 27100 (Italy); Altieri, S. [Istituto Nazionale di Fisica Nucleare, Sezione di Pavia 27100, Italy and Dipartimento di Fisica, Università di Pavia, Pavia 27100 (Italy)

    2015-07-15

    Purpose: Many types of lung tumors have a very poor prognosis due to their spread in the whole organ volume. The fact that boron neutron capture therapy (BNCT) would allow for selective targeting of all the nodules regardless of their position, prompted a preclinical feasibility study of ex situ BNCT at the thermal neutron facility of RA-3 reactor in the province of Buenos Aires, Argentina. (L)-4p-dihydroxy-borylphenylalanine fructose complex (BPA-F) biodistribution studies in an adult sheep model and computational dosimetry for a human explanted lung were performed to evaluate the feasibility and the therapeutic potential of ex situ BNCT. Methods: Two kinds of boron biodistribution studies were carried out in the healthy sheep: a set of pharmacokinetic studies without lung excision, and a set that consisted of evaluation of boron concentration in the explanted and perfused lung. In order to assess the feasibility of the clinical application of ex situ BNCT at RA-3, a case of multiple lung metastases was analyzed. A detailed computational representation of the geometry of the lung was built based on a real collapsed human lung. Dosimetric calculations and dose limiting considerations were based on the experimental results from the adult sheep, and on the most suitable information published in the literature. In addition, a workable treatment plan was considered to assess the clinical application in a realistic scenario. Results: Concentration-time profiles for the normal sheep showed that the boron kinetics in blood, lung, and skin would adequately represent the boron behavior and absolute uptake expected in human tissues. Results strongly suggest that the distribution of the boron compound is spatially homogeneous in the lung. A constant lung-to-blood ratio of 1.3 ± 0.1 was observed from 80 min after the end of BPA-F infusion. The fact that this ratio remains constant during time would allow the blood boron concentration to be used as a surrogate and indirect

  3. Course of operators of the RA-3 reactor

    International Nuclear Information System (INIS)

    Caligiuri, G.A.

    1983-01-01

    Description of the fundamental principles of the nuclear reactors' control systems. The RA-3 reactor's control and measurement systems are principally described, without setting aside the basic criteria for the design of an appropriate instrumentation for the control of a nuclear reactor, as well as the theory on which the functioning of the several detectors and equipments used in a nuclear instrumentation are based. The main purpose of this course is that of serving, preferentially as a text, for the training of personnel which shall perform operation tasks in this reactor. The work includes three well-defined sections. The first two ones make an introduction to the subject, while the third one, extending to more than half-work, deals with the general description of the system in which the control and operation logic of RA-3 are included. (R.J.S) [es

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

    International Nuclear Information System (INIS)

    Vicens, Hugo E.; Quintana, Jorge A.

    2001-01-01

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

  5. Radiation protection at the RA Reactor in 1993, RA research reactor, Part

    International Nuclear Information System (INIS)

    Ninkovic, M.; Pavlovic, R.; Mandic, M.; Sipka, V.; Grsic, Z.

    1993-01-01

    Radiation protection tasks which enable safe operation of the RA reactor, and are defined according the the legal regulations and IAEA safety recommendations are sorted into four categories in this report: (1) Control of the working environment, dosimetry and radiation protection at the RA reactor; (2) decontamination, collecting and treatment of fluid effluents and solid wastes; (3) Radioactivity control in the vicinity of the reactor and (4)meteorology measurements; (3). Each of the category is described as a separate annex of this report [sr

  6. RA Reactor; Reaktor RA

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1978-02-15

    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. [Serbo-Croat] Pored osnovnih karakeristika reaktora RA, organizacije rada i finansijskih pokazatelja, razmatra se stanje opreme reaktora nakon 18 godina rada, pitanja dozvole za rad sa 80% obogacenim gorivom, problem skladistenja isluzenog goriva u bazenu zgrade reaktora i potreba za obnavljanjem komponenti opreme, pre svega elektronske.

  7. RA Research nuclear reactor, Part II: radiation protection at the RA reactor in 1987

    International Nuclear Information System (INIS)

    Ninkovic, M.; Ajdacic, N.; Zaric, M.; Vukovic, Z.

    1987-01-01

    Radiation protection tasks which enable safe operation of the RA reactor, and are defined according the the legal regulations and IAEA safety recommendations are sorted into four categories in this report: (1) Control of the working environment, dosimetry at the RA reactor and radiation protection; (2) Radioactivity control in the vicinity of the reactor and meteorology measurements; (3) Decontamination and relevant actions, collecting and treatment of fluid effluents; and and solid radioactive wastes [sr

  8. Radiation protection at the RA Reactor in 1988, Part -2, RA reactor annual report

    International Nuclear Information System (INIS)

    Ninkovic, M.; Ajdacic, N.; Zaric, M.; Vukovic, Z.

    1988-01-01

    Radiation protection tasks which enable safe operation of the RA reactor, and are defined according the the legal regulations and IAEA safety recommendations are sorted into four categories in this report: (1) Control of the working environment, dosimetry at the RA reactor and radiation protection; (2) Radioactivity control in the vicinity of the reactor and meteorology measurements; (3) Decontamination and relevant actions, collecting and treatment of fluid effluents; and and solid radioactive wastes [sr

  9. RA Reactor; Reaktor RA

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1989-07-01

    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. [Serbo-Croat] Ovo (prvo) poglavlje sadrzi sledece: Opis reaktora RA; semu organizacije rada i rukovodjenja; prava i duznosti direktora i rukovodioca pogona reaktora, propise o rezimu rada i kretanja u zgradi reaktora, propise o izvodjenju eksperimenata, propise o unosenju uzoraka u eksperimentalne kanale reaktora.

  10. RA Reactor operation and maintenance (I-IX), part VII, Task 3.08/04, Refurbishment of the RA reactor

    International Nuclear Information System (INIS)

    Zecevic, V.

    1963-12-01

    This volume covers the following reports concerned with the maintenance and repair work of the RA reactor: repair of the technical water system; maintenance of the transportation equipment; vacuuming and drying during refurbishment; repair and decontamination of the distillation device; and the report on participation of the operational dosimetry division in the RA reactor refurbishment activities

  11. Radiation protection at the RA Reactor in 1998, RA reactor annual report, Part -2

    International Nuclear Information System (INIS)

    Ninkovic, M.; Pavlovic, R.; Mandic, M.; Pavlovic, S.; Grsic, Z.

    1998-01-01

    Radiation protection tasks which enable safe operation of the RA reactor, and are defined according the the legal regulations and IAEA safety recommendations are sorted into four categories in this report: (1) Control of the working environment, dosimetry at the RA reactor; (2) Radioactivity control in the vicinity of the reactor and meteorology measurements; (3) Collecting and treatment of fluid effluents; and (4) radioactive wastes, decontamination and actions. Each of the category is described as a separate annex of this report [sr

  12. RA Reactor operation and maintenance (I-IX), Part IV, Task 3.08/04, Refurbishment of the RA reactor

    International Nuclear Information System (INIS)

    Zecevic, V.

    1963-12-01

    This volume contains reports describing maintenance and repair work of the RA reactor instrumentation, equipment of the reactor dosimetry control system, and equipment for regulation and control systems

  13. RA reactor exploitation, task 3.08/01

    International Nuclear Information System (INIS)

    Zecevic, V.

    1963-01-01

    During 1963 the RA reactor was operated for 1852 hours at mean power of 5.7 MW (total power production was 10716 MWh). Reactor was used for irradiation according to the demand of 356 users, and 15 experiments. The reason for decreased operation in comparison with the previous year was repair of all the reactor equipment and decontamination of the heavy water system. This report contains detailed data about reactor power, reactivity changes and fuel burnup. Mean monthly usage of the reactor experimental channels as well as samples which were irradiated are part of this report

  14. RA reactor exploitation, task 3.08/01; Zadatak 3.08/01 - Eksploatacija reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

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

    1963-12-15

    During 1963 the RA reactor was operated for 1852 hours at mean power of 5.7 MW (total power production was 10716 MWh). Reactor was used for irradiation according to the demand of 356 users, and 15 experiments. The reason for decreased operation in comparison with the previous year was repair of all the reactor equipment and decontamination of the heavy water system. This report contains detailed data about reactor power, reactivity changes and fuel burnup. Mean monthly usage of the reactor experimental channels as well as samples which were irradiated are part of this report.

  15. RA Research nuclear reactor Part 1, RA Reactor operation and maintenance in 1987

    International Nuclear Information System (INIS)

    Sotic, O.; Martinc, R.; Cupac, S.; Sulem, B.; Badrljica, R.; Majstorovic, D.; Sanovic, V.

    1987-01-01

    RA research reacto was not operated due to the prohibition issued in 1984 by the Government of Serbia. Three major tasks were finished in order to fulfill the licensing regulations about safety of nuclear facilities which is the condition for obtaining permanent operation licence. These projects involved construction of the emergency cooling system, reconstruction of the existing special ventilation system, and renewal of the system for electric power supply of the reactor systems. Renewal of the RA reactor instrumentation system was initiated. Design project was done by the Russian Atomenergoeksport, and is foreseen to be completed by the end of 1988. The RA reactor safety report was finished in 1987. This annual report includes 8 annexes concerning reactor operation, activities of services and financial issues, and three special annexes: report on testing the emergency cooling system, report on renewal of the RA reactor and design specifications for reactor renewal and reconstruction [sr

  16. RA Research reactor, Annual report 1988

    International Nuclear Information System (INIS)

    Sotic, O.

    1988-12-01

    Annual report concerning the project 'RA research nuclear reactor' for 1989, financed by the Serbian ministry of science is divided into two parts. First part is concerned with RA reactor operation and maintenance, which is the task of the Division for reactor engineering of the Institute for multidisciplinary studies and RA reactor engineering. Second part deals with radiation protection activities at the RA reactor which is the responsibility of the Institute for radiation protection. Scientific council of the Institute for multidisciplinary studies and RA reactor engineering has stated that this report describes adequately the activity and tasks fulfilled at the RA reactor in 1989. The scope and the quality of the work done were considered successful both concerning the maintenance and reconstruction, as well as radiation protection activities [sr

  17. 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

  18. 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

  19. RA-0 reactor. New neutronic calculations; Reactor RA-0. Nuevos calculos neutronicos

    Energy Technology Data Exchange (ETDEWEB)

    Rumis, D; Leszczynski, F

    1991-12-31

    An updating of the neutronic calculations performed at the RA-0 reactor, located at the Natural, Physical and Exact Sciences Faculty of Cordoba National University, are herein described. The techniques used for the calculation of a reactor like the RA-0 allows prediction in detail of the flux behaviour in the core`s interior and in the reflector, which will be helpful for experiments design. In particular, the use of WIMSD4 code to make calculations on the reactor implies a novelty in the possible applications of this code to solve the problems that arise in practice. (Author). [Espanol] En este trabajo se actualizan los calculos neutronicos realizados para el reactor RA-0, instalado en la Facultad de Ciencias Exactas, Fisicas y Naturales de la Universidad Nacional de Cordoba. Se describen los calculos realizados hasta la fecha y los resultados obtenidos. Las tecnicas incorporadas al calculo de un reactor como el RA-0 permiten predecir en detalle el comportamiento del flujo en el interior del nucleo y en el reflector, lo que sera una importante ayuda en el diseno de experimentos. En particular, el empleo del codigo WIMSD4 para calculos del reactor completo constituye una novedad en las posibles aplicaciones de ese codigo para resolver problemas que se presentan en la practica. (Autor).

  20. RA Reactor operation and maintenance (I-IX), Part IV, Task 3.08/04, Refurbishment of the RA reactor; Pogon i odrzavanje reaktora RA (I-IX), IV Deo, Zadatak 3.08/04 Remont reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

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

    1963-12-15

    This volume contains reports describing maintenance and repair work of the RA reactor instrumentation, equipment of the reactor dosimetry control system, and equipment for regulation and control systems.

  1. Use of plate fuel elements for the RA3 reactor

    International Nuclear Information System (INIS)

    Parodi, C.; Parkanski, D.; Higa, M.; Marajofsky, A.

    1992-01-01

    The RA3 reactor is a pool reactor, redesigned for 5 MW dissipation. Nineteen plates are used in each fuel element. The utilization of 20% enriched U, gives the possibility of the development of rod type fuel with Al/U 3 O 8 cermets. The thermohydraulic and neutronic conditions are studied in this work in order to satisfy the stipulated power. In addition, the fabrication conditions of Al/U 3 O 8 and Al/U 3 O 8 /Zr H 2 cermets with densities within the limits imposed by the thermohydraulics and neutronics conditions are studied. (author)

  2. RA Research nuclear reactor - Annual report 1987

    International Nuclear Information System (INIS)

    1987-12-01

    Annual report concerning the project 'RA research nuclear reactor' for 1987, financed by the Serbian ministry of science is divided into two parts. First part is concerned with RA reactor operation and maintenance, which is the task of the Division for reactor engineering of the Institute for multidisciplinary studies and RA reactor engineering. Second part deals with radiation protection activities at the RA reactor which is the responsibility of the Institute for radiation protection. Scientific council of the Institute for multidisciplinary studies and RA reactor engineering has stated that this report describes adequately the activity and tasks fulfilled at the RA reactor in 1989. The scope and the quality of the work done were considered successful both concerning the maintenance and reconstruction, as well as radiation protection activities [sr

  3. Research nuclear reactor RA - Annual Report 1989

    International Nuclear Information System (INIS)

    Sotic, O.

    1989-12-01

    Annual report concerning the project 'RA research nuclear reactor' for 1989, financed by the Serbian ministry of science is divided into two parts. First part is concerned with RA reactor operation and maintenance, which is the task of the Division for reactor engineering of the Institute for multidisciplinary studies and RA reactor engineering. Second part deals with radiation protection activities at the RA reactor which is the responsibility of the Institute for radiation protection. Scientific council of the Institute for multidisciplinary studies and RA reactor engineering has stated that this report describes adequately the activity and tasks fulfilled at the RA reactor in 1989. The scope and the quality of the work done were considered successful both concerning the maintenance and reconstruction, as well as radiation protection activities [sr

  4. RA Reactor operation and maintenance (I-IX), part VII, Task 3.08/04, Refurbishment of the RA reactor; Pogon i odrzavanje reaktora (I-IX), VII Deo, Zadatak 3.08/04 Remont reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

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

    1963-12-15

    This volume covers the following reports concerned with the maintenance and repair work of the RA reactor: repair of the technical water system; maintenance of the transportation equipment; vacuuming and drying during refurbishment; repair and decontamination of the distillation device; and the report on participation of the operational dosimetry division in the RA reactor refurbishment activities.

  5. Reproduction of the RA reactor fuel element fabrication; Reprodukcija izrade gorivnog elementa za reaktor RA

    Energy Technology Data Exchange (ETDEWEB)

    Novakovic, M [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1961-12-15

    This document includes the following nine reports: Final report on task 08/12 - testing the Ra reactor fuel element; design concept for fabrication of RA reactor fuel element; investigation of the microstructure of the Ra reactor fuel element; Final report on task 08/13 producing binary alloys with Al, Mo, Zr, Nb and B additions; fabrication of U-Al alloy; final report on tasks 08/14 and 08/16; final report on task 08/32 diffusion bond between the fuel and the cladding of the Ra reactor fuel element; Final report on task 08/33, fabrication of the RA reactor fuel element cladding; and final report on task 08/36, diffusion of solid state metals. Ovaj rad sadrzi devet priloga: 1. Zavrsni izvestaj o podzadatku 08/12, ispitivanje elementa goriva reaktora RA; 2. Koncepcija izrade gorivnog elementa reaktora RA; 3. Ispitivanje mikrostrukture gorivnog elementa reaktora RA; 4. Zavrsni izvestaj o podzadatku 08/13, dobijanje binarnih legura urana sa legirajucim komponentama Al, Mo, Zr, Nb i B; 5. Dobijanje legure U-Al; 6. Zavrsni izvestaj o podzadacima 08/14 i 08/16; 7. Zavrsni izvestaj o podzadatku 08/32, difuziona veza goriva i kosuljice gorivnog elementa reaktora RA; 8. Zavrsni izvestaj o podzadatku 08/33, izrada kosuljice gorivnog elementa reaktora RA; 9. Zavrsni izvestaj o podzadatku 08/36, difuzija kod metala u cvrstom stanju.

  6. RA Research nuclear reactor, Part II - radiation protection at the RA nuclear reactor in 1984; Istrazivacki nuklearni reaktor RA - Deo II - zastita od zracenja kod nuklearnog reaktora RA u 1984. godini

    Energy Technology Data Exchange (ETDEWEB)

    Ninkovic, M; Ajdacic, N; Zaric, M; Vukovic, Z [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

    1984-12-15

    Radon protection tasks which enable safe operation of the RA reactor, and are defined according the the legal regulations and IAEA safety recommendations are sorted into four categories in this report: (1) Control of the working environment, dosimetry at the RA reactor; (2) Radioactivity control in the vicinity of the reactor and meteorology measurements; (3) Collecting and treatment of fluid effluents; and (4) radioactive wastes, decontamination and actions. Each category is described as a separate annex of this report.

  7. Measurements of neutron flux in the RA reactor

    International Nuclear Information System (INIS)

    Raisic, N.

    1961-12-01

    This report includes the following separate parts: Thermal neutron flux in the experimental channels od RA reactor; Epithermal neutron flux in the experimental channels od RA reactor; Fast neutron flux in the experimental channels od RA reactor; Thermal neutron flux in the thermal column and biological experimental channel; Neutronic measurements in the RA reactor cell; Temperature reactivity coefficient of the RA reactor; design of the device for measuring the activity of wire [sr

  8. Regulations for RA reactor operation; Propisi nuklearnog reaktora 'RA'

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1980-09-15

    Regulations for RA reactor operation are written in accordance with the legal regulations defined by the Law about radiation protection and related legal acts, as well as technical standards according to the IAEA recommendations. The contents of this book include: fundamental data about the reactor; legal regulations for reactor operation; organizational scheme for reactor operation; general and detailed instructions for operation, behaviour in the reactor building, performing experiments; operating rules for operation under steady state and accidental conditions. [Serbo-Croat] Propisi o radu nuklearnog reaktora RA pisani su tako da svi zakonski propisi definisani 'Zakonom o zastiti od jonizujuceg zracenja' i pratecim propisima (devet pravilnika) kao i tehnicke norme prema preporukama MAAE budu postovani u punoj meri pri radu reaktora. Sadrzaj ove knjige obuhvata: osnovne podatke o reaktoru; zakonske propise; organizaciju rada reaktora RA; opste propise o rezimu rada, kretanju u zgradi reaktora, izvodjenju eksperimenata; pogonske propise za rad u normalnom rezimu i u slucaju udesa.

  9. The design of a fuel element for the RA-3 reactor (Ezeiza Atomic Center)

    International Nuclear Information System (INIS)

    Agueda, Horacio C.; Estevez, Esteban; Gerding, Jose R.; Markiewicz, Mario E.

    2003-01-01

    Some features of the mechanical design of the low enrichment fuel element for the RA-3 reactor are described, with emphasis in those aspects of the original design that have been modified considering the experience acquired in the design of other fuel elements. The proposed modification is based fundamentally on the replacement of all welded joints by screwed joints, which facilitates the manufacture of the fuel element, avoiding the distortions produced by the welds used at present and contributing to the fulfillment of the foreseen tolerances. A basic characteristic of this design is a careful manufacture of the fuel element's structural components in order to assure an assembling of the fuel element that fulfills the tolerances intrinsically required. The fuel is designed for the RA-3 reactor and uses U 3 O 8 or U 3 Si 2 as carrying phase of the fissile material with an enrichment of 19.70% of 235 U. The design verification was performed by analytical and numerical methods, and is supported by testing of materials in laboratory, hydrodynamics tests and performance evaluations of the fuel elements in the RA-3 reactor. (author)

  10. Measurements of neutron flux in the RA reactor; Merenje karakteristika neutronskog fluksa u reaktoru RA

    Energy Technology Data Exchange (ETDEWEB)

    Raisic, N [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1961-12-15

    This report includes the following separate parts: Thermal neutron flux in the experimental channels od RA reactor; Epithermal neutron flux in the experimental channels od RA reactor; Fast neutron flux in the experimental channels od RA reactor; Thermal neutron flux in the thermal column and biological experimental channel; Neutronic measurements in the RA reactor cell; Temperature reactivity coefficient of the RA reactor; design of the device for measuring the activity of wire. [Serbo-Croat] Ovaj izvestaj sadrzi sledece referate: Fluks termalnih neutrona u eksperimentalnim kanalima reaktora RA; Fluks epitermalnih neutrona u eksperimentalnim kanalima reaktora RA; Fluks brzih neutrona u eksperimentalnim kanalima reaktora RA; Fluks termalnih neurona u termalnoj koloni i bioloskom eksperimentalnom kanalu; Neutronska merenja u elementarnoj celiji reaktora RA; Temperaturni koeficijent reaktivnosti reaktora RA; Projekat uredjaja za merenje radioaktivnosti zice.

  11. RA Research reactor, Annual report 1988; Istrazivacki nuklearni reaktor RA - Izvestaj za 1988. godinu

    Energy Technology Data Exchange (ETDEWEB)

    Sotic, O [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1988-12-15

    Annual report concerning the project 'RA research nuclear reactor' for 1989, financed by the Serbian ministry of science is divided into two parts. First part is concerned with RA reactor operation and maintenance, which is the task of the Division for reactor engineering of the Institute for multidisciplinary studies and RA reactor engineering. Second part deals with radiation protection activities at the RA reactor which is the responsibility of the Institute for radiation protection. Scientific council of the Institute for multidisciplinary studies and RA reactor engineering has stated that this report describes adequately the activity and tasks fulfilled at the RA reactor in 1989. The scope and the quality of the work done were considered successful both concerning the maintenance and reconstruction, as well as radiation protection activities. [Serbo-Croat] Godisnji izvestaj po projektu 'Istrazivacki nuklearni reaktor RA' za 1989. godinu, koji finansira republicka zajednica za nauku SR Srbije po ugovoru br. 3705/1 sastoji se iz dva dela. Prvi deo obuhvata pogon i odrzavanje nuklearnog reaktora RA, sto predstavlja obavezu Odeljenja za reaktorski inzenjering u sastavu OOUR Instituta za multidisciplinarna istrazivanja i inzenjering RA. Drugi deo obuhvata poslove zastite od zracenja na reaktoru RA, sto predstavlja obavezu OOUR Instituta za zastitu od zracenja 'Zastita'. Naucno vece Instituta za multidisciplinarna istrazivanja i inzenjering RA ocenilo je da sadrzina ovog izvestaja odgovara izvrsenim poslovima na reaktoru RA u 1989. godini. Pozitivno se ocenjuje obim i kvalitet izvrsenih radova kako u pogledu odrzavanja i rekonstrukcije reaktora, tako i u pogledu poslova zastite od zracenja izvrsenih kod njega.

  12. RA Reactor applications, Annex A

    International Nuclear Information System (INIS)

    Cupac, S.; Vukadin, Z.

    2000-01-01

    Full text: In 2000 Ra reactor was not operated. New instrumentation is not complete, without it, it is not possible to think about reactor start-up. Since 1985, when reactor operation was forbidden, there are 480 fuel elements left in 48 fuel channels in the reactor core. Heavy water was removed from the reactor core because of the repair of the heavy water pumps in 1986. The old instrumentation was removed. Eleven years after being left to its own destiny, it would be difficult to imagine that anybody would think of reactor restart without examining the state of reactor vessel and other vital reactor components. Maintaining the reactor under existing conditions without final decision about restart or permanent shutdown is destructive for this nuclear facility. The existing state that pertains for more than 10 years would have only one result, destruction of the RA reactor [sr

  13. RA Reactor applications, Annex A

    International Nuclear Information System (INIS)

    Cupac, S.; Vukadin, Z.

    1998-01-01

    Full text: In 1998 Ra reactor was not operated. New instrumentation is not complete, without it, it is not possible to think about reactor start-up. Since 1985, when reactor operation was forbidden, there are 480 fuel elements left in 48 fuel channels in the reactor core. Heavy water was removed from the reactor core because of the repair of the heavy water pumps in 1986. The old instrumentation was removed. Eleven years after being left to its own destiny, it would be difficult to imagine that anybody would think of reactor restart without examining the state of reactor vessel and other vital reactor components. Maintaining the reactor under existing conditions without final decision about restart or permanent shutdown is destructive for this nuclear facility. The existing state that pertains for more than 10 years would have only one result, destruction of the RA reactor [sr

  14. RA Reactor applications, Annex A

    International Nuclear Information System (INIS)

    Cupac, S.; Vukadin, Z.

    1996-01-01

    Full text: In 2000 Ra reactor was not operated. New instrumentation is not complete, without it, it is not possible to think about reactor start-up. Since 1985, when reactor operation was forbidden, there are 480 fuel elements left in 48 fuel channels in the reactor core. Heavy water was removed from the reactor core because of the repair of the heavy water pumps in 1986. The old instrumentation was removed. Eleven years after being left to its own destiny, it would be difficult to imagine that anybody would think of reactor restart without examining the state of reactor vessel and other vital reactor components. Maintaining the reactor under existing conditions without final decision about restart or permanent shutdown is destructive for this nuclear facility. The existing state that pertains for more than 10 years would have only one result, destruction of the RA reactor [sr

  15. Reproduction of the RA reactor fuel element fabrication

    International Nuclear Information System (INIS)

    Novakovic, M.

    1961-12-01

    This document includes the following nine reports: Final report on task 08/12 - testing the Ra reactor fuel element; design concept for fabrication of RA reactor fuel element; investigation of the microstructure of the Ra reactor fuel element; Final report on task 08/13 producing binary alloys with Al, Mo, Zr, Nb and B additions; fabrication of U-Al alloy; final report on tasks 08/14 and 08/16; final report on task 08/32 diffusion bond between the fuel and the cladding of the Ra reactor fuel element; Final report on task 08/33, fabrication of the RA reactor fuel element cladding; and final report on task 08/36, diffusion of solid state metals [sr

  16. RA Research nuclear reactor Part 1, RA Reactor operation and maintenance in 1987; Istrazivacki nuklearni reaktor RA Deo 1 - Pogon i odrzavanje nuklearnog reaktora RA u 1987. godini

    Energy Technology Data Exchange (ETDEWEB)

    Sotic, O; Martinc, R; Cupac, S; Sulem, B; Badrljica, R; Majstorovic, D; Sanovic, V [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1987-12-15

    RA research reacto was not operated due to the prohibition issued in 1984 by the Government of Serbia. Three major tasks were finished in order to fulfill the licensing regulations about safety of nuclear facilities which is the condition for obtaining permanent operation licence. These projects involved construction of the emergency cooling system, reconstruction of the existing special ventilation system, and renewal of the system for electric power supply of the reactor systems. Renewal of the RA reactor instrumentation system was initiated. Design project was done by the Russian Atomenergoeksport, and is foreseen to be completed by the end of 1988. The RA reactor safety report was finished in 1987. This annual report includes 8 annexes concerning reactor operation, activities of services and financial issues, and three special annexes: report on testing the emergency cooling system, report on renewal of the RA reactor and design specifications for reactor renewal and reconstruction. [Serbo-Croat] Reaktor RA nije radio usled zabrane Izvsnog veca Skupstine Srbije od 27. avgusta 1984. U cilju povecanja pouzdanosti rada reaktora a da bi se udovoljilo zakonskim propisima sto je uslov za dobijanje stalne dozvole za rad realizovana su tri velika zahvata na reaktoru RA. Ovi zahvati obuhvatili su izgradnju sistema za hladjenje jezgra reaktora u slucaju nuzde, rekonstukciju postojeceg sistema specijalne ventilacije i rekonstrukciju sistema napajanja elektricnom energijom neophodnih potrosaca reaktora RA. Zapoceti su radovi na modernizaciji intrumentacije reaktora RA, projekat je izradjen u sovjetskoj organizaciji Atomenergoeksport, a trebalo bi da se realizuje do kraja 1989. godine. U cilju povecanja prostora za skladistenje ozracenog nuklearnog goriva i njegovog efikasnijeg koriscenja, izradjen je su projekti za rekonstrukciju postojecih uredjaja za rukovanje gorivom, povecanje smestajnog kapaciteta i preciscavanje vode u bazenima za odlezavanje. Realizaija ovih

  17. Measurements at the RA Reactor related to the VISA-2 project - Part 1, Start-up of the RA reactor and measurement of new RA reactor core parameters

    International Nuclear Information System (INIS)

    Markovic, H.

    1962-07-01

    The objective of the measurements was determining the neutron flux in the RA reactor core. Since the number of fuel channels is increased from 56 to 68 within the VISA-2 project, it was necessary to attain criticality of the RA reactor and measure the neutron flux properties. The 'program of RA reactor start-up' has been prepared separately and it is included in this report. Measurements were divided in two phases. First phase was measuring of the neutron flux after the criticality was achieved but at zero power. During phase two measurements were repeated at several power levels, at equilibrium xenon poisoning. This report includes experimental data of flux distributions and absolute values of the thermal and fast neutron flux in the RA reactor experimental channels and values of cadmium ratio for determining the neutron epithermal flux. Data related to calibration of regulatory rods for cold un poisoned core are included [sr

  18. Research nuclear reactor RA - Annual Report 1989; Istrazivacki nuklearni reaktor RA - Izvestaj za 1989. godinu

    Energy Technology Data Exchange (ETDEWEB)

    Sotic, O [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1989-12-15

    Annual report concerning the project 'RA research nuclear reactor' for 1989, financed by the Serbian ministry of science is divided into two parts. First part is concerned with RA reactor operation and maintenance, which is the task of the Division for reactor engineering of the Institute for multidisciplinary studies and RA reactor engineering. Second part deals with radiation protection activities at the RA reactor which is the responsibility of the Institute for radiation protection. Scientific council of the Institute for multidisciplinary studies and RA reactor engineering has stated that this report describes adequately the activity and tasks fulfilled at the RA reactor in 1989. The scope and the quality of the work done were considered successful both concerning the maintenance and reconstruction, as well as radiation protection activities. [Serbo-Croat] Godisnji izvestaj po projektu 'Istrazivacki nuklearni reaktor RA' za 1989. godinu, koji finansira republicka zajednica za nauku SR Srbije po ugovoru br. 3705/1 sastoji se iz dva dela. Prvi deo obuhvata pogon i odrzavanje nuklearnog reaktora RA, sto predstavlja obavezu Odeljenja za reaktorski inzenjering u sastavu OOUR Instituta za multidisciplinarna istrazivanja i inzenjering RA. Drugi deo obuhvata poslove zastite od zracenja na reaktoru RA, sto predstavlja obavezu OOUR Instituta za zastitu od zracenja 'Zastita'. Naucno vece Instituta za multidisciplinarna istrazivanja i inzenjering RA ocenilo je da sadrzina ovog izvestaja odgovara izvrsenim poslovima na reaktoru RA u 1989. godini. Pozitivno se ocenjuje obim i kvalitet izvrsenih radova kako u pogledu odrzavanja i rekonstrukcije reaktora, tako i u pogledu poslova zastite od zracenja izvrsenih kod njega.

  19. Dosimetry and radiobiology at the new RA-3 reactor boron neutron capture therapy (BNCT) facility: Application to the treatment of experimental oral cancer

    Energy Technology Data Exchange (ETDEWEB)

    Pozzi, E. [Research and Production Reactors, National Atomic Energy Commission, Ezeiza Atomic Center (Argentina); Department of Radiobiology, National Atomic Energy Commission, Constituyentes Atomic Center (Argentina)], E-mail: epozzi@cnea.gov.ar; Nigg, D.W. [Idaho National Laboratory, Idaho Falls (United States); Miller, M.; Thorp, S.I. [Instrumentation and Control Department, National Atomic Energy Commission, Ezeiza Atomic Center (Argentina); Heber, E.M. [Department of Radiobiology, National Atomic Energy Commission, Constituyentes Atomic Center (Argentina); Zarza, L.; Estryk, G. [Research and Production Reactors, National Atomic Energy Commission, Ezeiza Atomic Center (Argentina); Monti Hughes, A.; Molinari, A.J.; Garabalino, M. [Department of Radiobiology, National Atomic Energy Commission, Constituyentes Atomic Center (Argentina); Itoiz, M.E. [Department of Radiobiology, National Atomic Energy Commission, Constituyentes Atomic Center (Argentina); Department of Oral Pathology, Faculty of Dentistry, University of Buenos Aires (Argentina); Aromando, R.F. [Department of Oral Pathology, Faculty of Dentistry, University of Buenos Aires (Argentina); Quintana, J. [Research and Production Reactors, National Atomic Energy Commission, Ezeiza Atomic Center (Argentina); Trivillin, V.A.; Schwint, A.E. [Department of Radiobiology, National Atomic Energy Commission, Constituyentes Atomic Center (Argentina)

    2009-07-15

    The National Atomic Energy Commission of Argentina (CNEA) constructed a novel thermal neutron source for use in boron neutron capture therapy (BNCT) applications at the RA-3 research reactor facility located in Buenos Aires. The aim of the present study was to perform a dosimetric characterization of the facility and undertake radiobiological studies of BNCT in an experimental model of oral cancer in the hamster cheek pouch. The free-field thermal flux was 7.1x10{sup 9} n cm{sup -2} s{sup -1} and the fast neutron flux was 2.5x10{sup 6} n cm{sup -2} s{sup -1}, indicating a very well-thermalized neutron field with negligible fast neutron dose. For radiobiological studies it was necessary to shield the body of the hamster from the neutron flux while exposing the everted cheek pouch bearing the tumors. To that end we developed a lithium (enriched to 95% in {sup 6}Li) carbonate enclosure. Groups of tumor-bearing hamsters were submitted to BPA-BNCT, GB-10-BNCT, (GB-10+BPA)-BNCT or beam only treatments. Normal (non-cancerized) hamsters were treated similarly to evaluate normal tissue radiotoxicity. The total physical dose delivered to tumor with the BNCT treatments ranged from 6 to 8.5 Gy. Tumor control at 30 days ranged from 73% to 85%, with no normal tissue radiotoxicity. Significant but reversible mucositis in precancerous tissue surrounding tumors was associated to BPA-BNCT. The therapeutic success of different BNCT protocols in treating experimental oral cancer at this novel facility was unequivocally demonstrated.

  20. Dosimetry and radiobiology at the new RA-3 reactor boron neutron capture therapy (BNCT) facility: Application to the treatment of experimental oral cancer

    International Nuclear Information System (INIS)

    Pozzi, E.; Nigg, D.W.; Miller, M.; Thorp, S.I.; Heber, E.M.; Zarza, L.; Estryk, G.; Monti Hughes, A.; Molinari, A.J.; Garabalino, M.; Itoiz, M.E.; Aromando, R.F.; Quintana, J.; Trivillin, V.A.; Schwint, A.E.

    2009-01-01

    The National Atomic Energy Commission of Argentina (CNEA) constructed a novel thermal neutron source for use in boron neutron capture therapy (BNCT) applications at the RA-3 research reactor facility located in Buenos Aires. The aim of the present study was to perform a dosimetric characterization of the facility and undertake radiobiological studies of BNCT in an experimental model of oral cancer in the hamster cheek pouch. The free-field thermal flux was 7.1x10 9 n cm -2 s -1 and the fast neutron flux was 2.5x10 6 n cm -2 s -1 , indicating a very well-thermalized neutron field with negligible fast neutron dose. For radiobiological studies it was necessary to shield the body of the hamster from the neutron flux while exposing the everted cheek pouch bearing the tumors. To that end we developed a lithium (enriched to 95% in 6 Li) carbonate enclosure. Groups of tumor-bearing hamsters were submitted to BPA-BNCT, GB-10-BNCT, (GB-10+BPA)-BNCT or beam only treatments. Normal (non-cancerized) hamsters were treated similarly to evaluate normal tissue radiotoxicity. The total physical dose delivered to tumor with the BNCT treatments ranged from 6 to 8.5 Gy. Tumor control at 30 days ranged from 73% to 85%, with no normal tissue radiotoxicity. Significant but reversible mucositis in precancerous tissue surrounding tumors was associated to BPA-BNCT. The therapeutic success of different BNCT protocols in treating experimental oral cancer at this novel facility was unequivocally demonstrated.

  1. Biological dosimetry studies for boron neutron capture therapy at the RA-1 research reactor facility

    International Nuclear Information System (INIS)

    Trivillin, Veronica A.; Heber, Elisa M.; Itoiz, Maria E.; Schwint, Amanda E.; Castillo, Jorge

    2004-01-01

    Initial physical dosimetry measurements have been completed using activation spectrometry and thermoluminescent dosimeters to characterize the BNCT facility developed at the RA-1 research reactor operated by the National Atomic Energy Commission in Buenos Aires. Biological dosimetry was performed employing the hamster cheek pouch oral cancer model previously validated for BNCT studies by our group. Results indicate that the RA-1 neutron source produces useful dose rates for BNCT studies but that some improvements in the initial configuration will be needed to optimize the spectrum for thermal-neutron BNCT research applications. (author)

  2. Possibilities for power reactor structural material and fuel testing in reactor RA; Mogucnosti reaktora RA za testiranje konstrukcionih materijala i goriva energetskih reaktora

    Energy Technology Data Exchange (ETDEWEB)

    Martinc, R; Lazarevic, Dj; Stefanovic, D; Cupac, S; Pesic, M [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1978-05-15

    Nuclear reactor RA at Vinca has been designed as a high flux general purpose research reactor. Among other it was intended to play a role of material testing reactor. A scope of activities of Material Laboratory and Reactor RA Department of Boris Kidric Institute is presented in this report. Reactor RA capacity for reactor structural material and fuel irradiation is also described. The increase of RA reactor irradiation capacity is based on the improvement of VISA type fuel channel for fast neutron irradiations, as well as on the general neutron flux increase, due to introduction of highly enriched uranium fuel into reactor core and the advanced in-core fuel management. The irradiation capacities described allow for the reactor material and fuel testing to the considerable extent. Istrazivacki reaktor RA u Vinci je projektovan kao visokofluksni istrazivacki reaktor opste namene. Pored ostalog, on je namenjen i za testiranje reaktorskih konstrukcionih materijala i goriva. U radu je dat pregled aktivnosti Laboratorije za materijale IBK i reaktora RA na tom podrucju, kao i opis povecanih mogucnosti reaktora RA za ozracivanje reaktorskih materijala i goriva u cilju njihovog testiranja. Povecanje mogucnosti reaktora RA zasniva se na usavrsavanju specijalnog gorivnog kanala tipa VISA (za ozracivanje materijala brzim neutronima), kao i na opstem povecanju neutronskog fluksa na osnovu uvodjenja i nacina koriscenja visokoobogacenog uranskog goriva u reaktoru RA. Opisane mogucnosti reaktora RA dozvoljavaju u znatnoj meri ispitivanje konstrukcionih materijala i goriva energetskih reaktora.

  3. In vivo BNCT in experimental and spontaneous tumors at RA-1 reactor

    International Nuclear Information System (INIS)

    Trivillin, Veronica A.; Heber, Elisa M.; Itoiz, Maria E.; Schwint, Amanda E.; Nigg, David W.

    2003-01-01

    Within the search for new applications of Boron Neutron Capture Therapy (BNCT) and the basic research oriented towards the study of BNCT radiobiology to optimize its therapeutic gain, we previously proposed and validated the hamster cheek pouch oral cancer model and showed, for the first time, the success of BNCT to treat oral cancer in an experimental model. The staff of the Ra-1 Reactor (Constituyentes Atomic Center) adapted the thermal beam and physical set-up to perform in vivo BNCT of superficial tumors in small animals. We preformed a preliminary characterization of the thermal beam, performed beam only irradiation of normal and tumor bearing hamsters and in vivo BNCT of experimental oral squamous cell carcinomas in hamsters mediated by boron phenylalanine (BPA) and GB-10 (Na 2 10 B 10 H 10 ). Having demonstrated the absence of radio toxic effects in healthy tissue and a therapeutic effect of in vivo BNCT in hamster cheek pouch tumors employing the Ra-1 thermal beam, we performed a feasibility study of the treatment by BNCT of 3 terminal cases of spontaneous head and neck squamous cell carcinoma in cats following the corresponding biodistribution studies. This was the first treatment of spontaneous tumors by BNCT in our country and the first treatment by BNCT in cats worldwide. This preclinical study in terminal cases showed significant tumor control by BNCT with no damage to normal tissue. (author)

  4. Irradiation of an uranium silicide prototype in RA-3 reactor

    International Nuclear Information System (INIS)

    Calabrese, R.; Estrik, G.; Notari, C.

    1996-01-01

    The factibility of irradiation of an uranium silicide (U 3 Si 2 ) prototype in the RA-3 reactor was studied. The standard RA-3 fuel element uses U 3 O 8 as fissible material. The enrichment of both standard and prototype is the same: 20% U 235 and also the frame geometry and number of plates is identical. The differences are in the plate dimensions and the fissile content which is higher in the prototype. The cooling conditions of the core allow the insertion of the prototype in any core position, even near the water trap, if the overall power is kept below 5Mw. Nevertheless, the recommendation was to begin irradiation near the periphery and later on move the prototype towards more central positions in order to increase the burnup rate. The prototype was effectively introduced in a peripheral position and the thermal fluxes were measured between plates with the foil activation technique. These were also evaluated with the fuel management codes and a reasonable agreement was found. (author). 5 refs., 3 figs., 3 tabs

  5. Research nuclear reactor RA, Annual Report 2001

    International Nuclear Information System (INIS)

    Sotic, O.

    2002-01-01

    During 2001, activities at the RA research nuclear reactor in were performed according to the Contract about financing of the RA reactor for the period January-December 2001, signed by the Ministry of Science, technology and development of the Republic of Serbia. RA reactor was not operated since shutdown in August 1984. Although, the most of the planned reconstruction activities were finished until 1991, the most important, which was concerned with exchange of the reactor instrumentation, financed by the IAEA, was interrupted due to international sanctions imposed on the country. Since 1992, all the renewal and reconstruction activities were ceased. Continuous aging and degradation of the equipment and facilities demand decision making about the future status of the Ra reactor. Until this decision is made it is an obligation to maintain control and maintenance of ventilation system, power supply, internal transportation system, spent fuel storage, hot cells, electronic fuel surveillance system, and part of the stationary dosimetry system. In 2001, apart from the mentioned activities, actions were undertaken related to maintenance of the reactor building and installations. The most important tasks fulfilled were: protection of the roof of the ventilation system building, purchase and installing the fire protection system and twelve new battery cells in the reactor building. There were no actions concerned with improvement of the conditions for intermediate spent fuel storage. With the support of IAEA, actions were initiated for possible transport of the spent fuel tu Russia. At the end of 2001, preparations were started for possible future decommissioning of the RA reactor. After, renewal of the membership of our country in the IAEA, the Government of Yugoslavia has declared its attitude about the intention of RA reactor decommissioning at the General Conference in September 2001 [sr

  6. RA Reactor operation and maintenance (I-IX), part VI, Task 3.08/04, Refurbishment of the RA reactor; Pogon i odrzavanje reaktora (I-IX), VI Deo, Zadatak 3.08/04 Remont reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

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

    1963-12-15

    During the period planned for maintenance and refurbishment of the RA reactor the gas reactor system including the ventilation system was inspected and tested, the components were cleaned. This report describes detailed instructions and actions concerning repair and decontamination of the gas and ventilation systems components.

  7. Nuclear Reactor RA Safety Report, Vol. 4, Reactor

    International Nuclear Information System (INIS)

    1986-11-01

    RA research reactor is thermal heavy water moderated and cooled reactor. Metal uranium 2% enriched fuel elements were used at the beginning of its operation. Since 1976, 80% enriched uranium oxide dispersed in aluminium fuel elements were gradually introduced into the core and are the only ones presently used. Reactor core is cylindrical, having diameter 40 cm and 123 cm high. Reaktor core is made up of 82 fuel elements in aluminium channels, lattice is square, lattice pitch 13 cm. Reactor vessel is cylindrical made of 8 mm thick aluminium, inside diameter 140 cm and 5.5 m high surrounded with neutron reflector and biological shield. There is no containment, the reactor building is playing the shielding role. Three pumps enable circulation of heavy water in the primary cooling circuit. Degradation of heavy water is prevented by helium cover gas. Control rods with cadmium regulate the reactor operation. There are eleven absorption rods, seven are used for long term reactivity compensation, two for automatic power regulation and two for safety shutdown. Total anti reactivity of the rods amounts to 24%. RA reactor is equipped with a number of experimental channels, 45 vertical (9 in the core), 34 in the graphite reflector and two in the water biological shield; and six horizontal channels regularly distributed in the core. This volume include detailed description of systems and components of the RA reactor, reactor core parameters, thermal hydraulics of the core, fuel elements, fuel elements handling equipment, fuel management, and experimental devices [sr

  8. Radiation protection at reactors RA and RB

    International Nuclear Information System (INIS)

    Ninkovic, M.

    2003-02-01

    Radiation protection activities at the RA and RB reactors are imposed by the existing legal regulations and international recommendations in this field. This annual report contains five parts which cover the following topics: Radiation safety, dosimetry control and technical radiation protection at reactors RA and RB; Handling of radioactive waste, actions and decontamination; Control of the environment (surroundings of RA and RB reactors) and meteorological measurements; Control of internal contamination and internal exposure; Health control od personnel exposed to radiation. Personnel as well as financial data are part of this report

  9. RA Research reactor, Part 1, Operation and maintenance of the RA nuclear reactor for 1986

    International Nuclear Information System (INIS)

    Sotic, O.; Martinc, R.; Cupac, S.; Sulem, B.; Badrljica, R.; Majstorovic, D.; Sanovic, V.

    1986-01-01

    In order to enable future reliable operation of the RA reactor, according to new licensing regulations, three major tasks started in 1984 were fulfilled: building of the new emergency system, reconstruction of the existing ventilation system, and reconstruction of the power supply system. Simultaneously in 1985/1986 renewal of the instrumentation and reconstruction of the system for handling and storage of the spent fuel in the reactor building have started. Design projects for these tasks are almost finished and the reconstruction of both systems is expected to be finished until 1988 and mid 1989 respectively. RA reactor Safety report was finished according to the recommendations of the IAEA. Investments in 1986 were used for 8000 kg of heavy water, maintenance of reactor systems and supply of new components, reconstruction of reactor systems. This report includes 8 annexes concerning reactor operation, activities of services and financial issues [sr

  10. Boron neutron capture synovectomy (BNCS) as a potential therapy for rheumatoid arthritis: radiobiological studies at RA-1 Nuclear Reactor in a model of antigen-induced arthritis in rabbits

    International Nuclear Information System (INIS)

    Trivillin, Veronica A.; Schwint, Amanda E.; Bruno, Leandro J.; Gatti, David A.; Stur, Mariela; Garabalino, Marcela A.; Hughes, Andrea Monti; Castillo, Jorge; Wentzeis, Luis; Scolari, Hugo; Pozzi, Emiliano C.C.; Feldman, Sara

    2016-01-01

    Rheumatoid arthritis is a chronic autoimmune pathology characterized by the proliferation and inflammation of the synovium. Boron neutron capture synovectomy (BNCS), a binary treatment modality that combines the preferential incorporation of boron carriers to target tissue and neutron irradiation, was proposed to treat the pathological synovium in arthritis. In a previous biodistribution study, we showed the incorporation of therapeutically useful boron concentrations to the pathological synovium in a model of antigen-induced arthritis (AIA) in rabbits, employing two boron compounds approved for their use in humans, i.e., decahydrodecaborate (GB-10) and boronophenylalanine (BPA). The aim of the present study was to perform low-dose BNCS studies at the RA-1 Nuclear Reactor in the same model. Neutron irradiation was performed post intra-articular administration of BPA or GB-10 to deliver 2.4 or 3.9 Gy, respectively, to synovium (BNCS-AIA). AIA and healthy animals (no AIA) were used as controls. The animals were followed clinically for 2 months. At that time, biochemical, magnetic resonance imaging (MRI) and histological studies were performed. BNCS-AIA animals did not show any toxic effects, swelling or pain on palpation. In BNCS-AIA, the post-treatment levels of TNF-α decreased in four of six rabbits and IFN-γ levels decreased in five of six rabbits. In all cases, MRI images of the knee joint in BNCS-AIA resembled those of no AIA, with no necrosis or periarticular effusion. Synovial membranes of BNCS-AIA were histologically similar to no AIA. BPA-BNCS and GB-10-BNCS, even at low doses, would be therapeutically useful for the local treatment of rheumatoid arthritis. (orig.)

  11. Boron neutron capture synovectomy (BNCS) as a potential therapy for rheumatoid arthritis: radiobiological studies at RA-1 Nuclear Reactor in a model of antigen-induced arthritis in rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Trivillin, Veronica A.; Schwint, Amanda E. [Comision Nacional de Energia Atomica (CNEA), Department of Radiobiology, San Martin, Provincia Buenos Aires (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Ciudad Autonoma de Buenos Aires (Argentina); Bruno, Leandro J.; Gatti, David A. [Universidad Nacional de Rosario, LABOATEM (Laboratorio de Biologia Osteoarticular, Ingenieria Tisular y Terapias Emergentes), Facultad de Ciencias Medicas, Rosario (Argentina); Stur, Mariela [Universidad Nacional de Rosario, Catedra de Diagnostico por Imagenes, Facultad de Ciencias Medicas, Rosario (Argentina); Garabalino, Marcela A.; Hughes, Andrea Monti [Comision Nacional de Energia Atomica (CNEA), Department of Radiobiology, San Martin, Provincia Buenos Aires (Argentina); Castillo, Jorge; Wentzeis, Luis; Scolari, Hugo [Comision Nacional de Energia Atomica (CNEA), Department of Reactors, San Martin, Provincia Buenos Aires (Argentina); Pozzi, Emiliano C.C. [Comision Nacional de Energia Atomica (CNEA), Department of Research and Production Reactors, Ezeiza, Province Buenos Aires (Argentina); Feldman, Sara [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Ciudad Autonoma de Buenos Aires (Argentina); Universidad Nacional de Rosario, LABOATEM (Laboratorio de Biologia Osteoarticular, Ingenieria Tisular y Terapias Emergentes), Facultad de Ciencias Medicas, Rosario (Argentina)

    2016-11-15

    Rheumatoid arthritis is a chronic autoimmune pathology characterized by the proliferation and inflammation of the synovium. Boron neutron capture synovectomy (BNCS), a binary treatment modality that combines the preferential incorporation of boron carriers to target tissue and neutron irradiation, was proposed to treat the pathological synovium in arthritis. In a previous biodistribution study, we showed the incorporation of therapeutically useful boron concentrations to the pathological synovium in a model of antigen-induced arthritis (AIA) in rabbits, employing two boron compounds approved for their use in humans, i.e., decahydrodecaborate (GB-10) and boronophenylalanine (BPA). The aim of the present study was to perform low-dose BNCS studies at the RA-1 Nuclear Reactor in the same model. Neutron irradiation was performed post intra-articular administration of BPA or GB-10 to deliver 2.4 or 3.9 Gy, respectively, to synovium (BNCS-AIA). AIA and healthy animals (no AIA) were used as controls. The animals were followed clinically for 2 months. At that time, biochemical, magnetic resonance imaging (MRI) and histological studies were performed. BNCS-AIA animals did not show any toxic effects, swelling or pain on palpation. In BNCS-AIA, the post-treatment levels of TNF-α decreased in four of six rabbits and IFN-γ levels decreased in five of six rabbits. In all cases, MRI images of the knee joint in BNCS-AIA resembled those of no AIA, with no necrosis or periarticular effusion. Synovial membranes of BNCS-AIA were histologically similar to no AIA. BPA-BNCS and GB-10-BNCS, even at low doses, would be therapeutically useful for the local treatment of rheumatoid arthritis. (orig.)

  12. RA Reactor applications, Annex A

    International Nuclear Information System (INIS)

    Martinc, R.; Cupac, S.; Stanic, A.

    1990-01-01

    RA reactor was not operated during the past five years due to the renewal and reconstruction of the reactor systems, which in underway. In the period from 1986-1990, reactor was operated only 144 MWh in 1986, for the need of testing the reactor systems and possibility of irradiating 125 I. Reactor will not be operated in 1991 because of the exchange of complete instrumentation which is planned to be finished by the end of 1991. It is expected to start operation in May 1992. That is why this annex includes the plan of reactor operation for period of nine months starting from from the moment of start-up. It is planned to operate the reactor at 0.02 MW power first three months, to increase the power gradually and reach 3.5 MW after 8 months of operation. It is foreseen to operate the reactor at 4.7 MW from the tenth month on [sr

  13. Moderators for the design of a cold neutron source for the RA 3 reactor

    International Nuclear Information System (INIS)

    Cantargi, F; Sbaffoni, M; Granada, R

    2004-01-01

    The cold neutron production of hydrogenous materials was studied, taking into account their radiation resistance, for the conceptual design of a cold neutron source for the RA-3 reactor.Low spontaneous release of chemical energy was found in mesitylene.Libraries for hidrogen in mesitylene were generated using the NJOY nuclear processing system and the resulting cross sections were compared with experimental data.Good agreement between measurements and calculations was found in those cases where data are available.New calculations using the RA-3 geometry and these validated libraries will be performed [es

  14. RA Research nuclear reactor - Annual report 1987; Istrazivacki nuklearni reaktor RA - Izvestaj o radu za 1987. godinu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1987-12-15

    Annual report concerning the project 'RA research nuclear reactor' for 1987, financed by the Serbian ministry of science is divided into two parts. First part is concerned with RA reactor operation and maintenance, which is the task of the Division for reactor engineering of the Institute for multidisciplinary studies and RA reactor engineering. Second part deals with radiation protection activities at the RA reactor which is the responsibility of the Institute for radiation protection. Scientific council of the Institute for multidisciplinary studies and RA reactor engineering has stated that this report describes adequately the activity and tasks fulfilled at the RA reactor in 1989. The scope and the quality of the work done were considered successful both concerning the maintenance and reconstruction, as well as radiation protection activities. [Serbo-Croat] Godisnji izvestaj po projektu 'Istrazivacki nuklearni reaktor RA' za 1987. godinu, koji finansira republicka zajednica za nauku SR Srbije po ugovoru br. 3509/1 sastoji se iz dva dela. Prvi deo obuhvata pogon i odrzavanje nuklearnog reaktora RA, sto predstavlja obavezu Odeljenja za reaktorski inzenjering u sastavu OOUR Instituta za multidisciplinarna istrazivanja i inzenjering RA. Drugi deo obuhvata poslove zastite od zracenja na reaktoru RA, sto predstavlja obavezu OOUR Instituta za zastitu od zracenja 'Zastita'. Naucno vece Instituta za multidisciplinarna istrazivanja i inzenjjring RA ocenilo je da sadrzina ovog izvestaja odgovara izvrsenim poslovima na reaktoru RA u 1989. godini. Pozitivno se ocenjuje obim i kvalitet izvrsenih radova kako u pogledu odrzavanja i rekonstrukcije reaktora, tako i u pogledu poslova zastite od zracenja izvrsenih kod njega.

  15. Kinetic parameters of the RB and RA reactors

    Energy Technology Data Exchange (ETDEWEB)

    Petrovic, M; Obradovic, D [Institute of nuclear sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

    1965-12-15

    In the paper the expressions for transfer functions of the zero power reactors, as well as power reactors of the RA reactor type are given, based on the space independent model. The modulation method for reactor transfer function measurements is explained. The results of the measurement and interpretation are given. The measurement were done on the RB and RA reactors in 'Boris Kidrich' Institute for Nuclear Sciences in Vincha (author)

  16. Research nuclear reactor RA - Annual Report 1994

    International Nuclear Information System (INIS)

    Sotic, O.

    1994-12-01

    Activities related to revitalisation of the RA reactor stared in 1986, were continued in 1991. A number of interventions on the reactor components were finished that are supposed to enable continuous and reliable operation. The last, and at the same time largest action, related to exchange of complete reactor instrumentation is underway, but it is behind the schedule in 1991 because the delivery of components from USSR is late. Production of this instruments is financed by the IAEA according to the contract signed in December 1988 with Russian Atomenergoexport. According to this contract, it has been planned that the RA reactor instrumentation should be delivered to the Vinca Institute by the end of 1990. Only 56% of the instrumentation was delivered until September 1991. Since then any delivery of components to Yugoslavia was stopped because of the temporary embargo imposed by the IAEA. In 1991 most of the existing RA reactor instrumentation was dismantled, only the part needed for basic measurements when reactor is not operated, was maintained. Activities related to improvement of Russian project were continued in 1994. Control and maintenance of the reactor components was done regularly and efficiently. Extensive repair of the secondary coolant loop is almost finished and will be completed in the first part of 1995 according to existing legal procedures and IAEA recommendations. Fuel inspection by the IAEA safeguards inspectors was done on a monthly basis. There have been on the average 47 employees at the RA reactor which is considered sufficient for maintenance and repair conditions. Research reactor RA Annual report for year 1991 is divided into two main parts to cover: (1) operation and maintenance and (2) activities related to radiation protection [sr

  17. RA reactor operation and maintenance in 1996, Part 1

    International Nuclear Information System (INIS)

    Sotic, O.; Cupac, S.; Sulem, B.; Zivotic, Z.; Mikic, N.; Tanaskovic, M.

    1996-01-01

    During the previous period RA reactor was not operated because the Committee of Serbian ministry for health and social care has cancelled the operation licence in August 1984. The reason was the non existing emergency cooling system and lack of appropriate filters in the special ventilation system. The planned major tasks were fulfilled: building of the new emergency cooling system, reconstruction of the existing ventilation system, and renewal of the reactor power supply system. The existing RA reactor instrumentation was dismantled. Renewal of the reactor instrumentation was started but but it is behind the schedule because the delivery of components from USSR was stopped for political reasons. Since the RA reactor is shutdown since 1984, it is high time for decision making of its future status. Possible solutions for the future status of the RA reactor discussed in this report are: renewal of reactor components for the reactor restart, conservation of the reactor (temporary shutdown) or permanent reactor shutdown. Control and maintenance of the reactor instrumentation and devices was done regularly but dependent on the availability of the spare parts and financial means. Training of the existing personnel and was done regularly, but the new staff has no practical training since the reactor is not operated. Lack of financial support influenced strongly the status of RA reactor [sr

  18. RA-0 reactor. New neutronic calculations

    International Nuclear Information System (INIS)

    Rumis, D.; Leszczynski, F.

    1990-01-01

    An updating of the neutronic calculations performed at the RA-0 reactor, located at the Natural, Physical and Exact Sciences Faculty of Cordoba National University, are herein described. The techniques used for the calculation of a reactor like the RA-0 allows prediction in detail of the flux behaviour in the core's interior and in the reflector, which will be helpful for experiments design. In particular, the use of WIMSD4 code to make calculations on the reactor implies a novelty in the possible applications of this code to solve the problems that arise in practice. (Author) [es

  19. RA Research nuclear reactor, Part I - RA nuclear reactor operation, maintenance and utilization in 1983

    International Nuclear Information System (INIS)

    Sotic, O.; Martinc, R.; Kozomara-Maic, S.; Cupac, S.; Raickovic, N.; Radivojevic, J.; Badrljica, R.; Majstorovic, D.; Sanovic, V.

    1983-12-01

    After regular shutdown in November 1982, inspection of the fuel elements from the RA reactor core which was done from December 1982 - February 1983 has shown that there are deposits of aluminium oxides on the surface of the fuel cladding. After restart The RA reactor was operated at power levels from 1.8 - 2 MW, with 80% enriched uranium dioxide fuel elements. It was found that there was no corrosion of the fuel element cladding and that it was not possible to find the cause of surface deposition on the cladding surfaces without further operation. It was decided to purify the heavy water permanently during operation and to increase the heavy water flow by operating two pumps. This procedure was adopted in order to decrease the possibility of corrosion. The Safety committee of the Institute has approved this procedure for operating the RA reactor in 1983. The core was made of 80% enriched fuel, critical experiments were done until June 1983, and after that the operation was continued at power levels up to 2 MW [sr

  20. Research nuclear reactor RA - Annual Report 1991

    International Nuclear Information System (INIS)

    Sotic, O.

    1992-01-01

    Activities related to revitalisation of the RA reactor stared in 1986, were continued in 1991. A number of interventions on the reactor components were finished that are supposed to enable continuous and reliable operation. The last, and at the same time largest action, related to exchange of complete reactor instrumentation is underway, but it is behind the schedule in 1991 because the delivery of components from USSR is late. Production of this instruments is financed by the IAEA according to the contract signed in December 1988 with Russian Atomenergoexport. According to this contract, it has been planned that the RA reactor instrumentation should be delivered to the Vinca Institute by the end of 1990. Only 56% of the instrumentation was delivered until September 1991. Since then any delivery of components to Yugoslavia was stopped because of the temporary embargo imposed by the IAEA. In 1991 most of the existing RA reactor instrumentation was dismantled, only the part needed for basic measurements when reactor is not operated, was maintained. Construction of some support elements is almost finished by the local staff. The Institute has undertaken this activity in order to speed up the ending of the project. If all the planned instrumentation would not arrive until the end of March 1992, it would not be possible to start the RA reactor testing operation in the first part of 1993, as previously planned. In 1991, 53 staff members took part in the activities during 1991, which is considered sufficient for maintenance and repair conditions. Research reactor RA Annual report for year 1991 is divided into two main parts to cover: (1) operation and maintenance and (2) activities related to radiation protection [sr

  1. Research nuclear reactor RA - Annual Report 1997; Istrazivacki nuklearni reaktor RA - Izvestaj za 1997. godinu

    Energy Technology Data Exchange (ETDEWEB)

    Sotic, O [Vinca Institute of Nuclear Sciences, Beograd (Serbia and Montenegro)

    1997-12-01

    RA reactor is not in operation since 1984, activities related to revitalisation of the RA reactor started in 1986. The planned actions related to renewal of the reactor components were finished except for the most important action, related to exchange of complete reactor instrumentation which was delayed. Only 80% of the instrumentation was delivered until September 1991. Since then any delivery of components to Yugoslavia was stopped because of the sanctions imposed to our country. The existing RA reactor instrumentation was dismantled. Control and maintenance of the reactor components was done regularly and efficiently. Fuel inspection by the IAEA safeguards inspectors was done on a monthly basis. There have been on the average 42 employees at the RA reactor which is considered sufficient for maintenance and repair conditions. The problem of financing the reactor activities and maintenance remains unsolved. Research reactor RA Annual report for year 1997 is divided into two main parts to cover: (1) operation and maintenance and (2) activities related to radiation protection. [Serbo-Croat] Reaktor RA nije u pogonu od 1984, aktivnosti na revitalizaciji, rekostrukciji i modernizaciji reaktorski sistema zapocete su 1986. godine. Okoncan je niz zahvata na opremi postrojenja kojima ce se u narednom periodu omoguciti kontinualan i pouzdan rad ovog reaktora. Poslednji, i ujedno najveci zahvat, koji se odnosi na zamenu celokupne instrumentacije kasni zbog zastoja u isporuci opreme koja se izradjuje u Sovjetskom savezu. Do septembra 1991. godine isporuceno svega 80% od predvidjene kolicine. Od tada je svaka isporuka obustavljena, a razlog je privremena zabrana na sve isporuke opreme za Jugoslaviju usled sankcija uvedenih od strane organizacije Ujedinjenih nacija. Demontirana je postojeca instrumentacija. Kontrola i odrzavanje celopkupne opreme postrojenja, kao i remontni radovi izvrsavani su redovno i efikasno. Kontrola goriva od strane safeguard inspektora MAAE obavljana

  2. Regulations for RA reactor operation

    International Nuclear Information System (INIS)

    1980-09-01

    Regulations for RA reactor operation are written in accordance with the legal regulations defined by the Law about radiation protection and related legal acts, as well as technical standards according to the IAEA recommendations. The contents of this book include: fundamental data about the reactor; legal regulations for reactor operation; organizational scheme for reactor operation; general and detailed instructions for operation, behaviour in the reactor building, performing experiments; operating rules for operation under steady state and accidental conditions [sr

  3. RA research reactor, Part 1, Operation and maintenance of the RA nuclear reactor for 1985

    International Nuclear Information System (INIS)

    Sotic, O.; Martinc, R.; Cupac, S.; Sulem, B.; Badrljica, R.; Majstorovic, D.; Sanovic, V.

    1985-01-01

    According to the plan, RA reactor was to be in operation in mid September 1985. But, since the building of the emergency cooling system, nor the reconstruction of the existing special ventilation system were not finished until the end of August reactor was not operated during 1985. During the previous four years reactor operation was limited by the temporary operating license issued by the Committee of Serbian ministry for health and social care, which was cancelled in August 1984. The reason was the non existing emergency cooling system and lack of appropriate filters in the special ventilation system. This temporary license has limited the reactor power to 2 MW from 1981-1984. Control and maintenance of the reactor instrumentation and tools was done regularly but dependent on the availability of the spare parts. In order to enable future reliable operation of the RA reactor, according to new licensing regulations, during 1984, three major tasks have started: building of the new emergency system, reconstruction of the existing ventilation system, and renewal of the reactor instrumentation. IAEA has approved the amount of 1,300,000 US dollars for the renewal of the instrumentation [sr

  4. Operation and maintenance of the RA reactor in 1964, I-II, Part II; Pogon i odrzavanje reaktora RA u 1964. godini, I-II, II Deo

    Energy Technology Data Exchange (ETDEWEB)

    Pavicevic, M [Institute of Nuclear Sciences Boris Kidric, Reaktor RA, Vinca, Beograd (Serbia and Montenegro)

    1964-12-15

    This volume of the report contains the following 15 Annexes: Improvement of the fuel cycle economy (record No. 37009803 in INIS DB); Analysis of neutron flux increase in horizontal experimental channels of the RA reactor record No. 37005698 in INIS DB); Application of the critical system for determining the thermal neutron flux in a research reactor with central horizontal reflector ( record No. 37055005 in INIS DB); Determining the capacity of the RA reactor heat exchanger dependent on the coolant water temperature and flow; Operation of the RA reactor in forced regime; Analysis of the CEN-132 heavy water pumps failures at the RA reactor from decontamination till present; Modifications in the vacuum loop of the distillation system; Report on decontamination of the evaporator and cleaning of the condenser of the distillation system; Operation of reactor at nominal power with reduced D{sub 2}O circulation; Cooling of the RA reactor with reduced flow rate in the heavy water loop; Measurement of the heavy water level in the fuel channels of the RA reactor; Conclusions of the experts group of the RA reactor at the meeting held on November 2 and 3 1964; Conclusions of the experts group at the meeting held on November 23 1964; After heat and the cooling problem after RA reactor shut-down; Measurement of noise and vibrations on the Ra reactor heavy water system; Calculation and measurement of the uranium temperature during irradiation in the experimental channel in the reflector of the RA reactor; Temperature measurement of the reactor materials samples irradiated in the fuel channels of the RA reactor; Study of the modifications in the synchronous generators, heavy water pumps and condenser batteries of the RA reactor.

  5. RA reactor reactivity changes before refurbishment - Task 3.08/02; Zadatak 3.08/02 - Promene reaktivnosti reaktora RA do remonta

    Energy Technology Data Exchange (ETDEWEB)

    Dobrosavljevic, N; Strugar, P; Stamenkovic, S [Institute of Nuclear Sciences Boris Kidric, Reaktor RA, Vinca, Beograd (Serbia and Montenegro)

    1963-12-15

    From the the end of 1959, when the RA reactor started operation until January 1963 reactor was operated with the initial fuel batch of 56 fuel channels. After 310 MWd 68 fuel channels were added to the reactor core, and after further 357 MWd the core was filled up to the maximum of 88 fuel channels. Basic reactor parameters were systematically measured during two years of operation. This report covers the measurements concerned directly with the reactor operation: calibration of the control rods and their reactivity worths during operation, determining the total built-in reactivity excess and its change during burnup, determination of reactivity dependence on the temperature, xenon effect in the core.

  6. RA Reactor operation and maintenance (I-IX), Part I

    International Nuclear Information System (INIS)

    Zecevic, V.

    1963-12-01

    The report on RA reactor operation and maintenance for year 1963 is divided in six tasks. This volume contains the introductory report, and three tasks of the final report, namely reactor exploitation, reactivity changes of the RA reactor before repair, planning of refuelling

  7. RA reactor operation and maintenance in 1992, Part 1

    International Nuclear Information System (INIS)

    Sotic, O.; Cupac, S.; Sulem, B.; Zivotic, Z.; Majstorovic, D.; Tanaskovic, M.

    1992-01-01

    During 1992 Ra reactor was not in operation. All the activities were fulfilled according to the previously adopted plan. Basic activities were concerned with revitalisation of the RA reactor and maintenance of reactor components. All the reactor personnel was busy with reconstruction and renewal of the existing reactor systems and building of the new systems, maintenance of the reactor devices. Part of the staff was trained for relevant tasks and maintenance of reactor systems [sr

  8. Status of the RA research reactor decommissioning project

    International Nuclear Information System (INIS)

    Ljubenov, V.; Nikolic, D.; Pesic, M.; Milosevic, M.; Kostic, Lj.; Steljic, M.; Sotic, O.; Antic, D. . E-mail address of corresponding author: vladan@vin.bg.ac.yu; Ljubenov, V.)

    2005-01-01

    The 6.5 MW heavy water RA research reactor at the VINCA Institute of Nuclear Sciences operated from 1959 to 1984. After 18 years of extended shutdown in 2002 it was decided that the reactor shutdown should be final. Preliminary decommissioning activities have been initiated by the end of 2002 under the Technical Co-operation Programme of the International Atomic Energy Agency. The objective of the project is to implement safe, timely and cost-effective decommissioning of the RA reactor up to unrestricted use of the site. Decommissioning project is closely related to two other projects: Safe Removal of the RA Reactor Spent Nuclear Fuel and Radioactive Waste Management in VINCA Institute. The main phases of the project include preparation of the detailed decommissioning plan, radiological characterization of the reactor site, dismantling and removal of the reactor components and structures, decontamination, final radiological site survey and the documentation of all the activities in order to obtain the approval for unrestricted use of the facility site. In this paper a review of the activities related to the preparation and realization of the RA reactor decommissioning project is given. Status of the project's organizational and technical aspects as for July 2004 are presented and plans for the forthcoming phases of the project realization are outlined. (author)

  9. RA Research reactor, Part 1, Operation and maintenance of the RA nuclear reactor for 1986; Istrazivacki nuklearni reaktor RA, deo 1, pogon i odrzavanje nukleanog reaktora RA u 1986. godini

    Energy Technology Data Exchange (ETDEWEB)

    Sotic, O; Martinc, R; Cupac, S; Sulem, B; Badrljica, R; Majstorovic, D; Sanovic, V [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1986-12-01

    In order to enable future reliable operation of the RA reactor, according to new licensing regulations, three major tasks started in 1984 were fulfilled: building of the new emergency system, reconstruction of the existing ventilation system, and reconstruction of the power supply system. Simultaneously in 1985/1986 renewal of the instrumentation and reconstruction of the system for handling and storage of the spent fuel in the reactor building have started. Design projects for these tasks are almost finished and the reconstruction of both systems is expected to be finished until 1988 and mid 1989 respectively. RA reactor Safety report was finished according to the recommendations of the IAEA. Investments in 1986 were used for 8000 kg of heavy water, maintenance of reactor systems and supply of new components, reconstruction of reactor systems. This report includes 8 annexes concerning reactor operation, activities of services and financial issues. [Serbo-Croat] Sa ciljem da se obezbedi pouzdan rad reaktora RA a u skladu sa zakonskim propisima, zavrsena su tri velika zahvata zapoceta 1984: izgradnja novog sistema za udesno hladjenje, rekonstrukcija postojeceg sistema za ventilaciju, i modernizacija reaktorske instrumentacije. Istovremeno tokom 1985/1986. zapoceta je modernizacija instrumentacije i rekonstrukcija sistema za rukovanje i skladistenje iskoriscenog goriva u zgradi reaktora. Projekti za navedene radove su vec zavrseni ili su u zavrsnoj fazi, a ocekuje se da ce rekonstrukcija oba sistema biti zavrsena do kraja 1988. odnosno sredine 1989. godine. Izrada izvestaja o sigurnosti reaktora RA, prema preporukama MAAE zavrsena je 1986. Investiciona ulaganja na reaktoru Ra u 1986. iskoriscena su za: nabavku 8000 kg teske vode, za investiciono odrzavanje reaktorskih sistema i nabavku opreme, za rekonstrukciju reaktorskih sistema. Ovaj izvestaj sadrzi 8 priloga koji opisuju rad reaktora, rad strucnih sluzbi i finansiranje.

  10. Instructions for RA reactor decontamination - Annex 10; Prilog 10 - Uputstvo za dekontaminaciju Reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1963-12-15

    Instructions for RA reactor decontamination includes: action plan for decontamination of the heavy water system by 7% water solution of H{sub 3}PO{sub 4} + 2% CrO{sub 3} acid; description of the preparatory work including calculation of the pipes volume and installation of special pipes; detailed instructions for decontamination procedure. [Serbo-Croat] Uputstvo za dekontaminaciju Reaktora RA sadrzi: plan operacija za dekontaminaciju sistema teske vode 7% vodenim rastvorom kiseline H{sub 3}PO{sub 4} + 2% CrO{sub 3}; opis pripremnih radova ukljucujuci proracun zapremine covovoda i montiranje posebnih cevovoda; detaljno uputstvo za izvodjenje operacija pri dekontaminaciji.

  11. Analysis of a possible experimental assessment of a prototype fuel element containing burnable poison in the RA-3 reactor

    International Nuclear Information System (INIS)

    Lerner, Ana Maria; Madariaga, Marcelo

    2002-01-01

    The Argentine RA-3 research reactor (5 MW) is presently operated with LEU fuel by the National Atomic Energy Commission (CNEA). It belongs to the group of nuclear installations controlled, from the radiological and nuclear safety point of view, by the Nuclear Regulatory Authority (ARN). A new type of fuel elements containing burnable absorbers, with similar enrichment as the standard fuel elements but greater fissile contents, has recently been proposed for a new Argentine reactor design (RRR). In this framework the ARN considers interesting, if technically possible, the performance of an experiment in the RA-3 reactor. The experiment might enable, for such fuel element containing burnable poison, the verification of its neutronic behaviour under irradiation as well as a validation of the calculation line by comparison to measured values. It should be desirable that such experiment could reproduce as much as possible those conditions estimated for the RRR reactor, still under design in Argentina, having Silicide fuel elements with burnable poison, in the shape of cadmium wires in their structure. We here analyse a possible experiment consisting in the loading of a prototype fuel element with burnable poison in a normally loaded RA-3 core configuration. It would essentially be a standard RA-3 fuel element, having cadmium wires in its frame. This experiment would enable the verification of the prototype behaviour under irradiation, its operation limits and conditions, and particularly, the reactivity safety margins established in Argentine Standards, both calculated and measured. The main part of the experiment would imply some 200 full power days of operation at 5 MW, which would be drastically reduced if the reactor power is increased to 10 MW, as foreseen. We also show that under the proposed conditions, the experiment would not represent a significant penalty to the reactor normal operation. (author)

  12. Adsorption of boron from boron-containing wastewaters by ion exchange in a continuous reactor

    International Nuclear Information System (INIS)

    Yilmaz, A. Erdem; Boncukcuoglu, Recep; Yilmaz, M. Tolga; Kocakerim, M. Muhtar

    2005-01-01

    In this study, boron removal from boron-containing wastewaters prepared synthetically was investigated. The experiments in which Amberlite IRA 743, boron specific resin was used were carried out in a column reactor. The bed volume of resin, boron concentration, flow rate and temperature were selected as experimental parameters. The experimental results showed that percent of boron removal increased with increasing amount of resin and with decreasing boron concentration in the solution. Boron removal decreased with increasing of flow rate and the effect of temperature on the percent of total boron removal increased the boron removal rate. As a result, it was seen that about 99% of boron in the wastewater could be removed at optimum conditions

  13. Research nuclear reactor RA - Annual Report 1996; Istrazivacki nuklearni reaktor RA - Izvestaj za 1996. godinu

    Energy Technology Data Exchange (ETDEWEB)

    Sotic, O [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1996-12-01

    Activities related to revitalisation of the RA reactor started in 1986, were continued in 1996. All the planned actions related to renewal of the reactor components were finished. The last, and at the same time most important action, related to exchange of complete reactor instrumentation is underway, delayed. The delivery of components from USSR is late. Production of this instruments is financed by the IAEA according to the contract signed in December 1988 with Russian Atomenergoexport. According to this contract, it has been planned that the RA reactor instrumentation should be delivered to the Vinca Institute by the end of 1990. Only 80% of the instrumentation was delivered until September 1991. Since then any delivery of components to Yugoslavia was stopped because of the temporary embargo imposed by the IAEA. The existing RA reactor instrumentation was dismantled. Control and maintenance of the reactor components was done regularly and efficiently. Fuel inspection by the IAEA safeguards inspectors was done on a monthly basis. There have been on the average 43 employees at the RA reactor which is considered sufficient for maintenance and repair conditions. The problem of financing the reactor activities and maintenance remains unsolved. Research reactor RA Annual report for year 1996 is divided into two main parts to cover: (1) operation and maintenance and (2) activities related to radiation protection. [Serbo-Croat] U toku 1996. godine nastavljeni su poslovi na revitalizaciji reaktora RA, zapocetoj 1986. godine. Okoncan je niz zahvata na opremi postrojenja kojima ce se u narednom periodu omoguciti kontinualan i pouzdan rad ovog reaktora. Poslednji, i ujedno najveci zahvat, koji se odnosi na zamenu celokupne instrumentacije kasni zbog zastoja u isporuci opreme koja se izradjuje u Sovjetskom savezu. Izradu ove opreme finansira Medjunarodna agencija za atomsku energiju kroz ugovor sklopljen decembra 1988. godine sa moskovskom firmom Atomenergoexport. Prema tom

  14. RA research reactor - properties and experimental capabilities

    International Nuclear Information System (INIS)

    Milosevic, M.; Martinc, R.

    1978-01-01

    The brief survey of the Reactor RA exploitation experience, as well as the reactor equipment state, after 18 years of operation is presented. The results of efforts spent on reactor characteristics improvement in order to ensure safe and reliable reactor operation for next 15-20 years, are described [sr

  15. Boron Neutron Capture Therapy (BCNT) for the Treatment of Liver Metastases: Biodistribution Studies of Boron Compounds in an Experimental Model

    Energy Technology Data Exchange (ETDEWEB)

    Marcela A. Garabalino; Andrea Monti Hughes; Ana J. Molinari; Elisa M. Heber; Emiliano C. C. Pozzi; Maria E. Itoiz; Veronica A. Trivillin; Amanda E. Schwint; Jorge E. Cardoso; Lucas L. Colombo; Susana Nievas; David W. Nigg; Romina F. Aromando

    2011-03-01

    Abstract We previously demonstrated the therapeutic efficacy of different boron neutron capture therapy (BNCT) protocols in an experimental model of oral cancer. BNCT is based on the selective accumulation of 10B carriers in a tumor followed by neutron irradiation. Within the context of exploring the potential therapeutic efficacy of BNCT for the treatment of liver metastases, the aim of the present study was to perform boron biodistribution studies in an experimental model of liver metastases in rats. Different boron compounds and administration conditions were assayed to determine which administration protocols would potentially be therapeutically useful in in vivo BNCT studies at the RA-3 nuclear reactor. A total of 70 BDIX rats were inoculated in the liver with syngeneic colon cancer cells DHD/K12/TRb to induce the development of subcapsular tumor nodules. Fourteen days post-inoculation, the animals were used for biodistribution studies. We evaluated a total of 11 administration protocols for the boron compounds boronophenylalanine (BPA) and GB-10 (Na210B10H10), alone or combined at different dose levels and employing different administration routes. Tumor, normal tissue, and blood samples were processed for boron measurement by atomic emission spectroscopy. Six protocols proved potentially useful for BNCT studies in terms of absolute boron concentration in tumor and preferential uptake of boron by tumor tissue. Boron concentration values in tumor and normal tissues in the liver metastases model show it would be feasible to reach therapeutic BNCT doses in tumor without exceeding radiotolerance in normal tissue at the thermal neutron facility at RA-3.

  16. RA Research reactor, Annual report 1986; Istrazivacki nuklearni reaktor RA - Izvestaj za 1986. godinu

    Energy Technology Data Exchange (ETDEWEB)

    Sotic, O [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1986-12-01

    Research reactor RA Annual report for year 1985 is divided into two main parts to cover: (1) operation and maintenance and (2) activities related to radiation protection. [Serbo-Croat] Godisnji izvestaj po projektu 'Istrazivacki nuklearni reaktor RA' za 1986 godinu sastoji se od dva dela: prvi deo obuhvata pogon i odzavanje reaktora RA, a drugi poslove zastite od zracenja na reaktoru RA.

  17. RA reactor operation and maintenance in 1989, Part 1

    International Nuclear Information System (INIS)

    Sotic, O.; Martinc, R.; Cupac, S.; Sulem, B.; Zivotic, Z.; Majstorovic, D.; Sanovic, V.

    1989-01-01

    During the previous period RA reactor was not operated because the Committee of Serbian ministry for health and social care has cancelled the operation licence in July 1984. The reason was the non existing emergency cooling system and lack of appropriate filters in the special ventilation system. The following major tasks were fulfilled: building of the new emergency cooling system, reconstruction of the existing ventilation system, and renewal of the power supply system. Project concerned with renewal of RA reactor complete instrumentation was started at the end of 1988. Contract was signed between the IAEA and Soviet Atomenergoexport for supplying the new instrumentation for the RA reactor. Project concerned with increase of the storage space and the efficiency of handling the spent fuel elements has started in 1988. In 1989, device for water purification designed by the reactor staff started operation and spent fuel handling equipment is being mounted. Training of the existing personnel and was done regularly, but the new staff has no practical training since the reactor is not operated. Lack of financial support influenced strongly the status of RA reactor [sr

  18. RA Research nuclear reactor, Part 1, RA reactor operation and maintenance in 1993, with comparative review for the period 1991 - 1993, Annex 3

    International Nuclear Information System (INIS)

    Sotic, O.; Cupac, S.; Sulem, B.; Zivotic, Z.; Mikic, N.; Tanaskovic, M.

    1993-01-01

    RA reactor was not operated during 1993 because of the complete instrumentation exchange. Although it has been planned to exchange the complete instrumentation until the end of 1993, and to start reactor operation in the first half of 1993 this was not fulfilled because the instrumentation was not delivered until the end of 1993. Main activities during past seven years were related to construction of the emergency cooling system; repair and reconstruction of the system for handling the spent fuel and improvement of spent fuel storage conditions; exchange of the aged instrumentation. Other reactor components and systems, reactor core, primary coolant loop and gas circulation system are in good condition concerning future start-up [sr

  19. Preparations for the shipment of RA-3 reactor irradiated fuel

    International Nuclear Information System (INIS)

    Goldschmidt, Adrian; Novara, Oscar; Lafuente, Jose

    2002-01-01

    During the last quarter of 2000, in the Radioactive Waste Management Area of the Argentine National Commission of Atomic Energy (CNEA), located at Ezeiza Atomic Center (CAE), activities associated to the shipment of 207 MTR spent fuels containing high enrichment uranium were carried out within the Foreign Research Reactor/Domestic Research Reactor Receipt Program launched by the US Department of Energy (DOE). The MTR spent fuel shipped to Savannah River Site (SRS) was fabricated in Argentina with 90% enriched uranium of US origin and it was utilized in the operation of the research and radioisotope production reactor RA-3 from 1968 until 1987. After a cooling period at the reactor, the spent fuel was transferred to the Central Storage Facility (CSF) located in the waste management area of CAE for interim storage. The spent fuel (SF) inventory consisted of 166 standard assemblies (SA) and 41 control assemblies (CA). Basically, the activities performed were the fuel conditioning operations inside the storage facility (remote transference of the assemblies to the operation pool, fuel cropping, fuel re-identification, loading in transport baskets, etc.) conducted by CNEA. The loading of the filled baskets in the transport casks (NAC-LWT) by means of intermediate transfer systems and loaded casks final preparations were conducted by NAC personnel (DOE's contractor) with the support of CNEA personnel. (author)

  20. RA Reactor operation and maintenance (I-IX), Part I; Pogon i odrzavanje reaktora RA (I-IX), I Deo

    Energy Technology Data Exchange (ETDEWEB)

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

    1963-12-15

    The report on RA reactor operation and maintenance for year 1963 is divided in six tasks. This volume contains the introductory report, and three tasks of the final report, namely reactor exploitation, reactivity changes of the RA reactor before repair, planning of refuelling.

  1. The determination of boron and carbon in reactor grade boron carbide

    International Nuclear Information System (INIS)

    Crossley, D.; Wood, A.J.; McInnes, C.A.J.; Jones, I.G.

    1978-09-01

    The sealed tube method of dissolution at high temperature and pressure has been successfully applied in the analysis of reactor grade boron carbide for the determination of boron. A 50 mg sample of boron carbide is completely dissolved by heating with concentrated nitric acid in a sealed tube at 300 0 C. The boron content of the resultant sample solution is determined by the mannitol potentiometric titration method. The precision of the method for the determination of 2.5 mg of boron using the Harwell automatic potentiometric titrator is 0.2% (coefficient of variation). The carbon content of a boron carbide sample is determined by combustion of the sample at 1050 0 C in a stream of oxygen using vanadium pentoxide to ensure the complete oxidation of the sample. The carbon dioxide produced from the sample is measured manometrically and the precision of the method for the determination of 4 mg of carbon is 0.4% (coefficient of variation). (author)

  2. Measurements at the RA Reactor related to the VISA-2 project - Part 1, Start-up of the RA reactor and measurement of new RA reactor core parameters; Fizicka merenja na reaktoru RA u vezi projekta VISA-2 - I deo, Pustanje u rad reaktora RA i merenje fizickih parametara novog jezgra reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

    Markovic, H [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1962-07-15

    The objective of the measurements was determining the neutron flux in the RA reactor core. Since the number of fuel channels is increased from 56 to 68 within the VISA-2 project, it was necessary to attain criticality of the RA reactor and measure the neutron flux properties. The 'program of RA reactor start-up' has been prepared separately and it is included in this report. Measurements were divided in two phases. First phase was measuring of the neutron flux after the criticality was achieved but at zero power. During phase two measurements were repeated at several power levels, at equilibrium xenon poisoning. This report includes experimental data of flux distributions and absolute values of the thermal and fast neutron flux in the RA reactor experimental channels and values of cadmium ratio for determining the neutron epithermal flux. Data related to calibration of regulatory rods for cold un poisoned core are included. [Serbo-Croat] Svrha merenja je odredjivanje neutronskog fluksa u reaktoru RA. S obzirom na uvecani broj tehnoloskih kanala of 56 na 68 u vezi projekta VISA-2, bilo je potrebno ponovo dovesti reaktora RA do kriticnosti i izvrsiti merenja karakteristika fluksa neutrona. Posebno je pripremljen 'program pustanja u pogon reaktora RA', koji je sadrzan u ovom dokumentu. Program merenja bio je podeljen na dve faze. Prva faza je merenje fluksa pre podizanju reaktora na nominalnu snagu. Slicna merenja vrsena su i na vecim snagama u drugoj fazi, pod uslovima ravnoteznog zatrovanja reaktora ksenonom, jer se tada pokazuju izvesne promene u odgovarajucim karakteristikama fluksa neutrona. Ovaj izvestaj sadrzi merene vrednosti raspodele fluksa i apsolutne vrednosti termalnih i brzih neutrona kao i kadmijumskih odnosa koji su korisceni za odredjivanje fluksa epitermalnih neutrona. Opisana je kalibracija regulacionih sipki za hladan nezatrovan reaktor.

  3. Actions needed for RA reactor exploitation - I-IV, Part I, Thermotechnical experiments related to RA reactor hot start-up; Radovi za potrebe eksploatacije reaktora RA - I-IV, I Deo, Termotehnicki eksperimenti u vezi pustanja rektora RA na snagu

    Energy Technology Data Exchange (ETDEWEB)

    Novakovic, M [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1961-12-15

    Heavy water coolant loop of the RA reactor includes the reactor, circulation pumps, heat exchangers and pipes. The objective of this task was measuring the thermal parameters of the RA reactor during operation. This report contains the results of the experiment, calculations of thermal regime for the outer and inner tubes, maximum temperature of the fuel element, fluid flow rate in the reactor channels, temperature of the coolant and fuel element cladding.

  4. Reactivity balance for a soluble boron-free small modular reactor

    Directory of Open Access Journals (Sweden)

    Lezani van der Merwe

    2018-06-01

    Full Text Available Elimination of soluble boron from reactor design eliminates boron-induced reactivity accidents and leads to a more negative moderator temperature coefficient. However, a large negative moderator temperature coefficient can lead to large reactivity feedback that could allow the reactor to return to power when it cools down from hot full power to cold zero power. In soluble boron-free small modular reactor (SMR design, only control rods are available to control such rapid core transient.The purpose of this study is to investigate whether an SMR would have enough control rod worth to compensate for large reactivity feedback. The investigation begins with classification of reactivity and completes an analysis of the reactivity balance in each reactor state for the SMR model.The control rod worth requirement obtained from the reactivity balance is a minimum control rod worth to maintain the reactor critical during the whole cycle. The minimum available rod worth must be larger than the control rod worth requirement to manipulate the reactor safely in each reactor state. It is found that the SMR does have enough control rod worth available during rapid transient to maintain the SMR at subcritical below k-effectives of 0.99 for both hot zero power and cold zero power. Keywords: Control Rod Worth, Reactivity Balance, Reactivity Feedback, Small Modular Reactor, Soluble Boron Free

  5. A study of computational dosimetry and boron biodistribution for ex – situ lung BNCT at RA-3 Reactor

    International Nuclear Information System (INIS)

    Garabalino, M.A.; Trivillin, V. A.; Monti Hughes, A.; Pozzi, E.C.C.; Thorp, S.; Curotto, P; Miller, M.; Santa Cruz, G.A.; Saint Martin, G.; Schwint, A.E.; González, S.J.; Farías, R.O; Portu, A.; Ferraris, S.; Santa María, J.; Lange, F.; Bortolussi, S.; Altieri, S.

    2013-01-01

    Within the context of the preclinical ex-situ BNCT Project for the treatment of diffuse lung metastases, we performed boron biodistribution studies in a sheep model and computational dosimetry studies in human lung to evaluate the potential therapeutic efficacy of the proposed technique. Herein we report preliminary data that supports the use of the sheep model as an adequate human surrogate in terms of boron kinetics and uptake in clinically relevant tissues. Furthermore, the estimation of the potential therapeutic efficacy of the proposed treatment in humans, based on boron uptake values in the large animal model, yields promising tumor control probability values even in the most conservative scenario considered. (author)

  6. RA reactor operation and maintenance

    International Nuclear Information System (INIS)

    Zecevic, V.

    1963-02-01

    This volume includes the final report on RA reactor operation and utilization of the experimental facilities in 1962, detailed analysis of the system for heavy water distillation and calibration of the system for measuring the activity of the air

  7. Nuclear reactors sources of contamination - RA reactor in Vinca as an example; Nuklearni reaktori kao izvori kontaminacije - Primer reaktora RA u Vinci -

    Energy Technology Data Exchange (ETDEWEB)

    Mitrovic, S; Djukic, Z; Dobrosavljevic, N [Institute of nuclear sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

    1966-03-15

    This study contains an analysis of possible contamination caused by reactor accidents. In addition to description of maximum credible accident impacts on the environment it covers the prevention and procedures to be undertaken in case of accident. The RA reactor was taken as an example. Since the probability of maximum credible accident is very low minor accident that could cause fission products release were analyzed. Analysis of the spent fuel storage pool at the RA reactor is included as well.

  8. Irradiation of an uranium silicide prototype in RA-3 reactor; Irradiacion de un elemento combustible prototipo de siliciuro de uranio en el RA-3

    Energy Technology Data Exchange (ETDEWEB)

    Calabrese, R; Estrik, G; Notari, C [Comision Nacional de Energia Atomica, San Martin (Argentina). Unidad de Actividad Reactores y Centrales Nucleares

    1997-12-31

    The factibility of irradiation of an uranium silicide (U{sub 3} Si{sub 2}) prototype in the RA-3 reactor was studied. The standard RA-3 fuel element uses U{sub 3} O{sub 8} as fissible material. The enrichment of both standard and prototype is the same: 20% U{sub 235} and also the frame geometry and number of plates is identical. The differences are in the plate dimensions and the fissile content which is higher in the prototype. The cooling conditions of the core allow the insertion of the prototype in any core position, even near the water trap, if the overall power is kept below 5Mw. Nevertheless, the recommendation was to begin irradiation near the periphery and later on move the prototype towards more central positions in order to increase the burnup rate. The prototype was effectively introduced in a peripheral position and the thermal fluxes were measured between plates with the foil activation technique. These were also evaluated with the fuel management codes and a reasonable agreement was found. (author). 5 refs., 3 figs., 3 tabs.

  9. Nuclear Reactor RA Safety Report, Vol. 8, Auxiliary system

    International Nuclear Information System (INIS)

    1986-11-01

    This volume describes RA reactor auxiliary systems, as follows: special ventilation system, special drainage system, hot cells, systems for internal transport. Ventilation system is considered as part of the reactor safety and protection system. Its role is eliminate possible radioactive particles dispersion in the environment. Special drainage system includes pipes and reservoirs with the safety role, meaning absorption or storage of possible radioactive waste water from the reactor building. Hot cells existing in the RA reactor building are designed for production of sealed radioactive sources, including packaging and transport [sr

  10. RA research nuclear reactor - Annual report 1985; Istrazivacki nuklearni reaktor RA - Izvestaj za 1985. godinu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1985-12-01

    Research reactor RA Annual report for year 1985 is divided into two main parts to cover: (1) operation and maintenance and (2) activities related to radiation protection. [Serbo-Croat] Godisnji izvestaj po projektu 'Istrazivacki nuklearni reaktor RA' za 1985 godinu sastoji se od dva dela: prvi deo obuhvata pogon i odzavanje reaktora RA, a drugi poslove zastite od zracenja na reaktoru RA.

  11. RA reactor operation and maintenance; Pogon i odrzavanje reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

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

    1963-02-15

    This volume includes the final report on RA reactor operation and utilization of the experimental facilities in 1962, detailed analysis of the system for heavy water distillation and calibration of the system for measuring the activity of the air.

  12. Research nuclear reactor RA - Annual Report 1991; Istrazivacki nuklearni reaktor RA - Izvestaj za 1991. godinu

    Energy Technology Data Exchange (ETDEWEB)

    Sotic, O [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1992-01-01

    Activities related to revitalisation of the RA reactor stared in 1986, were continued in 1991. A number of interventions on the reactor components were finished that are supposed to enable continuous and reliable operation. The last, and at the same time largest action, related to exchange of complete reactor instrumentation is underway, but it is behind the schedule in 1991 because the delivery of components from USSR is late. Production of this instruments is financed by the IAEA according to the contract signed in December 1988 with Russian Atomenergoexport. According to this contract, it has been planned that the RA reactor instrumentation should be delivered to the Vinca Institute by the end of 1990. Only 56% of the instrumentation was delivered until September 1991. Since then any delivery of components to Yugoslavia was stopped because of the temporary embargo imposed by the IAEA. In 1991 most of the existing RA reactor instrumentation was dismantled, only the part needed for basic measurements when reactor is not operated, was maintained. Construction of some support elements is almost finished by the local staff. The Institute has undertaken this activity in order to speed up the ending of the project. If all the planned instrumentation would not arrive until the end of March 1992, it would not be possible to start the RA reactor testing operation in the first part of 1993, as previously planned. In 1991, 53 staff members took part in the activities during 1991, which is considered sufficient for maintenance and repair conditions. Research reactor RA Annual report for year 1991 is divided into two main parts to cover: (1) operation and maintenance and (2) activities related to radiation protection. [Serbo-Croat] U 1991. godini nastavljeni su poslovi na revitalizaciji reaktora RA, zapocetoj 1986. godine. Okoncan je niz zahvata na opremi postrojenja kojima ce se u narednom periodu omoguciti kontinualan i pouzdan rad ovog reaktora. Poslednji, i ujedno najveci

  13. RA Research reactor, Annual report 1971

    International Nuclear Information System (INIS)

    Milosevic, D. et al.

    1971-12-01

    During 1971, the RA Reactor was operated at nominal power of 6.5 MW for 190 days, and 50 days at lower power levels. Total production mounted to 31606 MWh which is 5.3% higher than planned, and the highest annual level since the reactor started operation. Reactor was used for irradiation and experiments according to the demand of 425 users, of which 370 from the Institute and 55 external users. This report contains detailed data about reactor power and experiments performed in 1971. Discrepancies from the action plan, meaning higher production was achieved in June and December due to special demand of the users. Total number of interruptions was lower than during all the previous years, and were caused mainly due to power cuts during reactor operation. There was no longer interruption caused by failures of the equipment. There was only on scram shutdown during this year caused by a false signal of the reactor control instrumentation. Shorter interruptions resulted from breaking of connectors in the technical water pipe system caused by soil sliding near the pumping station on the Danube. Total personnel exposure dose was lower than during previous years. There was no accident nor any event that could be called accidental. Decontamination od surfaces was less than during previous years. It was concluded that the successful operation in 1971 resulted from efficient work during past years. But, some of the activities were interrupted due to undefined policy concerned with operation of the RA reactor and financial issues. This involves study of the possibility to use highly enriched fuel that would increase the useful neutron flux and the reactor compatibility with similar reactors for the future ten years. Another project that has been interrupted is construction of the emergency core cooling system which is important for the reactor safety. Financial problems have influenced not only the reactor operation but the number of employees, which could cause negative

  14. Safety shutdowns and failures of the RA reactor equipment; Sigurnosna zaustavljanja i kvarovi opreme na reaktoru RA

    Energy Technology Data Exchange (ETDEWEB)

    Mitrovic, S [Institut za nuklearne nauke ' Boris Kidric' , Vinca, Belgrade (Yugoslavia)

    1966-07-01

    This report is an attempt of statistical analysis of the failures occurred during RA reactor operation. A list of failures occurred on the RA equipment during 1965 is included. Failures were related to the following systems: dosimetry system (22%), safety and control system (7%), heavy water system (2%), technical water (4%), helium system (2%), measuring instruments (30%), transport, ventilation, power supply systems (32%). A review of safety shutdowns from 1962 to 1966 is included as well, as a comparison with three similar reactors. Although the number of events used for statistical analysis was not adequate, it has been concluded that RA reactor operation was stable and reliable.

  15. RA research reactor in 'Vinca' Institute-approach to the decommissioning

    International Nuclear Information System (INIS)

    Ljubenov, V.Lj.; Pesic, M.P.; Sotic, O.

    2002-01-01

    In this paper short overview of decommissioning process of research reactors according to IAEA standards and world practice is given. Basic technical characteristics and details of operational history of the RA research reactor in Vinca Institute of Nuclear Sciences are present. The main nuclear and radiation safety problems related to the RA reactor facility are defined and the outlines of the future decommissioning project are proposed. (author)

  16. Power measurement of the RA-3 reactor using the neutron noise technique and {sup 16}N; Medicion de la potencia del reactor RA-3, mediante la tecnica de ruido neutronico y nitrogeno 16

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, Angel [Comision Nacional de Energia Atomica, General San Martin (Argentina). Dept. Reactores y Centrales Nucleares

    2003-07-01

    This work describes a measurement method based on the neutron noise technique which is used for determining the relation between the power and the currents of two ionization chambers. These chambers are sensitive to the gamma radiation from the {sup 16}N decay produced in the RA-3 reactor core. The power during operation is obtained from the calibration factors by measuring those currents. As this calibration factors depend on the cooler flow that circulates in the reactor core and in the {sup 16}N measuring system, an estimator, that is a function of the ratio of this currents, is proposed in order to detect flow changes. (author)

  17. RA reactor operation and maintenance in 1992, Part 1; Deo 1 - Pogon i odrzavanje nuklearnog reaktoro RA u 1992. Godini

    Energy Technology Data Exchange (ETDEWEB)

    Sotic, O; Cupac, S; Sulem, B; Zivotic, Z; Majstorovic, D; Tanaskovic, M [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1992-12-01

    During 1992 Ra reactor was not in operation. All the activities were fulfilled according to the previously adopted plan. Basic activities were concerned with revitalisation of the RA reactor and maintenance of reactor components. All the reactor personnel was busy with reconstruction and renewal of the existing reactor systems and building of the new systems, maintenance of the reactor devices. Part of the staff was trained for relevant tasks and maintenance of reactor systems. [Serbo-Croat] U toku 1992 godine poslovi u okviru projekta 'Istrazivacki nuklearni reaktor RA' obavljani su u skladu sa programom i planom rada. Osnovne aktivnosti na kojima je radjeno odnosile su se na revitalizaciju reaktora RA, kao i na odrzavanje opreme. U ovom periodu reaktor nije bio u pogonu. Svo osoblje je bilo angazovano na poslovima rekonstrukcije i modernizacije postojecih i dogradnje novih reaktorskih sistema, na odrzavanju opreme a deo tehnickog osoblja je bio obucavan za vrsenje odgovarajucih poslova u pogonu i odrzavanju opreme.

  18. Communications programme for the RA nuclear reactor decommission

    International Nuclear Information System (INIS)

    Milanovic, S.; Antic, D.

    2002-01-01

    During the decommissioning of the RA research nuclear reactor at the VINCA Institute of Nuclear Sciences, an adequate number of radiation and contamination surveys should be conduced to assure radiological safety of the workers, the public and the environment. Public would like to know more about the nuclear and radiological safety. The communications programme defines the ways to informing the public, its representatives and the information media about the health and safety aspects of the activities during the RA nuclear reactor decommission. (author)

  19. Research nuclear reactor RA - Annual Report 1994; Istrazivacki nuklearni reaktor RA - Izvestaj za 1994. godinu

    Energy Technology Data Exchange (ETDEWEB)

    Sotic, O [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1994-12-01

    Activities related to revitalisation of the RA reactor stared in 1986, were continued in 1991. A number of interventions on the reactor components were finished that are supposed to enable continuous and reliable operation. The last, and at the same time largest action, related to exchange of complete reactor instrumentation is underway, but it is behind the schedule in 1991 because the delivery of components from USSR is late. Production of this instruments is financed by the IAEA according to the contract signed in December 1988 with Russian Atomenergoexport. According to this contract, it has been planned that the RA reactor instrumentation should be delivered to the Vinca Institute by the end of 1990. Only 56% of the instrumentation was delivered until September 1991. Since then any delivery of components to Yugoslavia was stopped because of the temporary embargo imposed by the IAEA. In 1991 most of the existing RA reactor instrumentation was dismantled, only the part needed for basic measurements when reactor is not operated, was maintained. Activities related to improvement of Russian project were continued in 1994. Control and maintenance of the reactor components was done regularly and efficiently. Extensive repair of the secondary coolant loop is almost finished and will be completed in the first part of 1995 according to existing legal procedures and IAEA recommendations. Fuel inspection by the IAEA safeguards inspectors was done on a monthly basis. There have been on the average 47 employees at the RA reactor which is considered sufficient for maintenance and repair conditions. Research reactor RA Annual report for year 1991 is divided into two main parts to cover: (1) operation and maintenance and (2) activities related to radiation protection. [Serbo-Croat] U 1994. godini nastavljeni su poslovi na revitalizaciji reaktora RA, zapocetoj 1986. godine. Okoncan je niz zahvata na opremi postrojenja kojima ce se u narednom periodu omoguciti kontinualan i

  20. Future prospects of reactor Ra at VINCA institute

    International Nuclear Information System (INIS)

    Davidovic, M.; Babic-Stojic, B.; Dobrijevic, R.

    1997-01-01

    Reactor RA at Nuclear Research Institute Vinca belongs to a group of the medium thermal neutron flux reactors, according to classification at end of nineties. At the beginning reactor RA has been used as a powerful source of neutrons and gamma-quanta for various experiments (interaction of neutrons and gamma-quanta with materials) and for production of artificial radioactive materials for commercial use. Very successful utilization of this neutron spectrum has been in its use for structural studies of crystal materials and liquid metals, for magnetic structure studies of various magnetic materials, as well as, dynamic properties of ferro magnetics, ferroelectrics, etc. This kind of spectrometers still exist at reactor RA and with an improved detection system could be used again if reactor starts functioning. Besides this, a part of activity was devoted to construction of neutron guide tubes for thermal neutrons and this could also be accomplished relatively easy in the future. A part of the activities of the reactor should in the future be devoted to the training of students in the field of solid state physics and nuclear physics. Particular attention will be paid to the use of established technologies in production of radioactive isotopes and a new class of isotopes for custom use will be developed as well as highly commercial and prospective products (silicon doping, radiography, etc.). (author)

  1. Nuclear Reactor RA Safety Report, Vol. 14, Safety protection measures

    International Nuclear Information System (INIS)

    1986-11-01

    Nuclear reactor accidents can be caused by three type of errors: failure of reactor components including (1) control and measuring instrumentation, (2) errors in operation procedure, (3) natural disasters. Safety during reactor operation are secured during its design and construction and later during operation. Both construction and administrative procedures are applied to attain safe operation. Technical safety features include fission product barriers, fuel elements cladding, primary reactor components (reactor vessel, primary cooling pipes, heat exchanger in the pump), reactor building. Safety system is the system for safe reactor shutdown and auxiliary safety system. RA reactor operating regulations and instructions are administrative acts applied to avoid possible human error caused accidents [sr

  2. RA reactor operation and maintenance in 1994, Part 1

    International Nuclear Information System (INIS)

    Sotic, O.; Cupac, S.; Sulem, B.; Zivotic, Z.; Mikic, N.; Tanaskovic, M.

    1994-01-01

    During the previous period RA reactor was not operated because the Committee of Serbian ministry for health and social care has cancelled the operation licence in August 1984. The reason was the non existing emergency cooling system and lack of appropriate filters in the special ventilation system. The planned major tasks were fulfilled: building of the new emergency cooling system, reconstruction of the existing ventilation system, and renewal of the reactor power supply system. The existing RA reactor instrumentation was dismantled, only the part needed for basic measurements when reactor is not operated, was maintained. Renewal of the reactor instrumentation was started but but it is behind the schedule because the delivery of components from USSR was stopped for political reasons. The spent fuel elements used from the very beginning of reactor operation are stored in the existing pools. Project concerned with increase of the storage space and the efficiency of handling the spent fuel elements has started in 1988 and was fulfilled in 1990. Control and maintenance of the reactor instrumentation and tools was done regularly but dependent on the availability of the spare parts. Training of the existing personnel and was done regularly, but the new staff has no practical training since the reactor is not operated. Lack of financial support influenced strongly the status of RA reactor [sr

  3. Status of RA3 conversion studies

    International Nuclear Information System (INIS)

    Testoni, J.

    1983-01-01

    Studies carried out at CNEA in Argentina for the conversion of the RA3 3.5 MW reactor to LEU fuel dealt with neutronic, thermal hydraulic, safety analysis, as well as fuel manufacture. Some of the results for the neutronic studies are reported

  4. RA reactor building and installations; Zgrada 'RA' i instalacije

    Energy Technology Data Exchange (ETDEWEB)

    Badrljica, R; Sanovic, V; Skoric, M [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1985-08-15

    RA reactor building is made of reinforced concrete and bricks. It is closed facility with a limited number of controlled openings, doors and windows. The site of the building is 100 m above the sea level, 20 m above the mean Danube level and 8 m above the level of the neighbouring stream Mlaka. The building consists of three parts: central prismatic part, annex - surrounding the central part and the sanitary corridor. The biggest space is the reactor hall. In addition to the detailed description and drawings of the reactor building this documents includes design specifications of: electrical installation, water supply system, sewage system, ventilation and heating, gas and compressed air systems. A separate chapter is devoted to fire protection. Zgrada reaktora RA izgradjena je od armiranog betona i opeke, kao zatvoreni objekat ogranicenog broja kontolisanih otvora, sa ogranicenim brojem vrata i prozora. Plato na kojem je zgrada izgradjena nalazi se na 100 m nadmorske visine, na 20 m iznad srednjeg vodostaja Dunava i 8 m iznad nivoa obliznjeg potoka Mlaka. Zgrada se sastoji iz tri dela: sredisnjeg prizmaticnog dela, aneksa - prstenastog okvira sredisnog dela i sanitarnog propusnika. Pojedinacno najveci prostor zauzima reaktorska hala. Pored detaljnog opisa i plana zgrade, ovaj dokument sadrzi projekat elektricne instalacije, projekat vodovoda i kanalizacije, ventilacije i grejanja, instalacije gasa i komprimovanog vazduha. Posebno poglavlje posveceno je protivpozarnoj zastiti.

  5. Research nuclear reactor RA - Annual report 1992; Istrazivacki nuklearni reaktor RA - Izvestaj za 1992. godinu

    Energy Technology Data Exchange (ETDEWEB)

    Sotic, O [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1992-12-01

    Research reactor RA Annual report for year 1992 is divided into two main parts to cover: (1) operation and maintenance and (2) activities related to radiation protection. First part includes 8 annexes describing reactor operation, activities of services for maintenance of reactor components and instrumentation, financial report and staffing. Second annex B is a paper by Z. Vukadin 'Recurrence formulas for evaluating expansion series of depletion functions' published in 'Kerntechnik' 56, (1991) No.6 (INIS record no. 23024136. Second part of the report is devoted to radiation protection issues and contains 4 annexes with data about radiation control of the working environment and reactor environment, description of decontamination activities, collection of radioactive wastes, and meteorology data. [Serbo-Croat] Godisnji izvestaj o radu nuklearnog reaktora RA za 1992. godinu sastoji se od dva dela: prvi deo obuhvata pogon i odzavanje reaktora RA, a drugi poslove zastite od zracenja na reaktoru RA. Prvi deo sadrzi 8 priloga, koji opisuju rad reaktora i poslove sluzbi za odrzavanje opreme i komponenti, finansijski izvestaj, kadrovsku strukturu osoblja reaktora. Drugi prilog (B) je rad Z. Vukadina 'Recurrence formulas for evaluating expansion series of depletion functions' objavljen u casopisu Kerntechnik, 1991. Drugi deo izvestaja o poslovima zastite od zracenja sadrzi 4 priloga sa podacima radijacione kontrole radne sredine i okoline reaktora, opis poslova dekontaminacije i sakupljanja radioaktivnih materija, kao i meteoroloske podatke.

  6. Nuclear Reactor RA Safety Report, Vol. 1, Introduction; Izvestaj o sigurnosti nuklearnog reaktora RA, Knjiga 1, Uvod

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1986-11-01

    Based on the agreement between governments of Socialist Federal Republic of Yugoslavia and USSR of January 28 1956, a contract was signed about construction of RA research reactor in the Boris Kidric Institute of nuclear sciences. Building of the RA reactor started in 1956, and has reached criticality in 1959. Since then it has been in almost permanent operation, except for five longer shutdown periods: in 1963 because of heavy water and primary coolant system contamination with cobalt; in 1970 because of transporting the heavy water to France for isotopic regeneration; in 1979/1980 and 1983 because of aluminium oxyhydrate deposition on the fuel element cladding in reactor active region; in 1985/1986 because of ventilation system reconstruction and construction of emergency core cooling system. RA reactor is a heavy water cooled and heavy water moderated research reactor. Since the beginning of its operation, 2% enriched metal uranium fuel was used. From 1976, 80% enriched uranium oxide fuel elements were used partially in some core regions and since 1981 the complete core was filled with this highly enriched fuel. RA reactor was designed to operate under normal conditions at 6.5 MW power and at 10 MW power under forced regime. As a powerful neutron source the reactor was meant to be used for research in the field of reactor and neutron physics, solid state physics, radiation chemistry, biology and radioactive isotopes production. RA reactor was build by Yugoslav companies based on USSR basic design project. Main components of the systems were produced in USSR. [Serbo-Croat] Na osnovu Sporazuma izmedju vlada SFRJ i SSSR od 28. januara 1956. godine, sklopljen je ugovor o izgradnji istrazivackog reaktora RA u Institutu za nuklearne nauke Boris Kidric u Vinci. Reaktor RA je poceo da se gradi 1956. godine, a kriticnost je postigao 1959. godine. Od tada je takoreci neprekidno bio u radu, izuzev u pet slucajeva duzeg stajanja: 1963. godine - zbog kontaminacije teske vode

  7. Nuclear Reactor RA Safety Report, Vol. 8, Auxiliary system; Izvestaj o sigurnosti nuklearnog reaktora RA, Knjiga 8, Pomocni sistemi

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1986-11-01

    This volume describes RA reactor auxiliary systems, as follows: special ventilation system, special drainage system, hot cells, systems for internal transport. Ventilation system is considered as part of the reactor safety and protection system. Its role is eliminate possible radioactive particles dispersion in the environment. Special drainage system includes pipes and reservoirs with the safety role, meaning absorption or storage of possible radioactive waste water from the reactor building. Hot cells existing in the RA reactor building are designed for production of sealed radioactive sources, including packaging and transport. [Serbo-Croat] Ova knjiga obuhvata opis pomocnih sistem reaktora RA: sistem specijalne ventilacije, sistem specijalne kanalizacije, vruce komore, sistemi za unutrasnji transport. Ventilacioni sistem je znacajan deo sistema zastite i sigurnosti reaktora. Njegova je uloga da onemoguci disperziju radioaktivnih cestica u okolinu. Sistem specijalne kanalizacije sastoji se od agregata, cevovoda i rezervoara sa sigurnosnom armaturom i ima zadatak da prihvata i u sebe deponuje radioaktivne otpadne vode iz objekarta reaktora RA. U zgradi reaktora RA postoje vruce komore koje su namenjene za proizvodnju zatvorenih izvora zracenje, ukljucujuci i mehanicku obradu, prepakivanje i transport.

  8. Tasks related to increase of RA reactor exploitation and experimental potential, 03. Crane for handling the vertical experimental channels of the RA reactor - design project

    International Nuclear Information System (INIS)

    Pavicevic, M.

    1963-07-01

    Within the work related to improvement of experimental potential of the RA reactor, this document describes the design project of the new crane for handling the vertical experimental channels of the RA reactor, engineering drawings of the crane main elements, mechanical part, design project of the electrical part of the crane and cost estimation

  9. Nuclear Reactor RA Safety Report, Vol. 14, Safety protection measures; Izvestaj o sigurnosti nuklearnog reaktora RA, Knjiga 14, Sigurnosne zastitne mere

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1986-11-01

    Nuclear reactor accidents can be caused by three type of errors: failure of reactor components including (1) control and measuring instrumentation, (2) errors in operation procedure, (3) natural disasters. Safety during reactor operation are secured during its design and construction and later during operation. Both construction and administrative procedures are applied to attain safe operation. Technical safety features include fission product barriers, fuel elements cladding, primary reactor components (reactor vessel, primary cooling pipes, heat exchanger in the pump), reactor building. Safety system is the system for safe reactor shutdown and auxiliary safety system. RA reactor operating regulations and instructions are administrative acts applied to avoid possible human error caused accidents. [Serbo-Croat] Uzroci udesa na nuklearnim reaktorima mogu se svrstati u jednu od sledece tri grupe: (1) otkaz pojedinih delova opreme, ukljucujuci mernu i kontrolnu instrumentaciju, (2) greske u pogonu i eksploataciji, (3) prirodne nepogode, katastrofe. Bezbednost i sigurnost u radu nuklearnog reaktora osiguravaju se odredjenim merama koje se preduzimaju pri njegovoj izgradnji i kasnije njegovoj elsploataciji. Te mere se mogu podeliti u sledece dve kategorije: (1) mere tehnicke zastite, i (2) administrativne mere. Mere tehnicke zastite sastoje se od barijere fissionih produkata, kosuljice gorivnih elemenata, primarnog kola reaktora RA (reaktorski sud, cevovod primarnog kola, toploizmenjivac u pimpi), zgrada reaktora. Sigurnosni sistem cini sistem za sigurnosno zaustavljanje reaktora i pomocni sigurnosni sistem. Kroz odgovarajuce propise i uputstva za rad na reaktoru RA primenjene su administrativne mere neophodne za sprecavanje udes koji bi mogao nastati kao posledica ljudskog faktora.

  10. Calculation of research reactor RA power at uncontrolled reactivity changes

    International Nuclear Information System (INIS)

    Cupac, S.

    1978-01-01

    The safety analysis of research reactor RA involves also the calculation of reactor power at uncontrolled reactivity changes. The corresponding computer code, based on Point Kinetics Model has been made. The short review of method applied for solving kinetic equations is given and several examples illustrating the reactor behaviour at various reactivity changes are presented. The results already obtained are giving rather rough picture of reactor behaviour in considered situations. This is the consequence of using simplified feed back and reactor cooling models, as well as temperature reactivity coefficients, which do not correspond to the actual reactor RA structure (which is now only partly fulfilled with 80% enriched uranium fuel). (author) [sr

  11. Modelling of the RA-1 reactor using a Monte Carlo code; Modelado del reactor RA-1 utilizando un codigo Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Quinteiro, Guillermo F; Calabrese, Carlos R [Comision Nacional de Energia Atomica, General San Martin (Argentina). Dept. de Reactores y Centrales Nucleares

    2000-07-01

    It was carried out for the first time, a model of the Argentine RA-1 reactor using the MCNP Monte Carlo code. This model was validated using data for experimental neutron and gamma measurements at different energy ranges and locations. In addition, the resulting fluxes were compared with the data obtained using a 3D diffusion code. (author)

  12. CAC-RA1 1958-1998. The first years of the Constituyentes Atomic Center (CAC). History of the first Argentine nuclear reactor (RA-1); CAC-RA-1 1958-1998. Los primeros anios del CAC. Historia del primer reactor nuclear argentino (RA-1)

    Energy Technology Data Exchange (ETDEWEB)

    Forlerer, Elena; Palacios, Tulio A [comps.

    1998-07-01

    After giving the milestones of the development of the Constituyentes Atomic Center since 1957, the history of the construction of the first nuclear reactor (RA-1) in Argentina, including the local fabrication of its fuel elements, is surveyed. The RA-1 reached criticality on January 17, 1958. The booklet commemorates the 40th year of the reactor operation.

  13. Optimization of the neutron calculation model for the RA-6 reactor

    International Nuclear Information System (INIS)

    Coscia, G.A.

    1981-01-01

    A model for the neutronic calculation of the RA-6 reactor which includes the codes ANISN and EQUIPOSE is analyzed. Starting with a brief description of the reactor, the core and its parts, the general scheme of calculation applied is presented. The fuel elements used were those which are utilized in the RA-3 reactor; this is of the MTR type with 90% enriched uranium. With the approximations used, an analysis of such model of calculation was made, trying to optimize it by reducing, if possible, the calculation time without loosing accuracy. In order to improve the calculation model, it is recomended a cross section data library specific for the enrichment of the fuel considered 90% and the incorporation of a more advanced code than EQUIPOISE which would be DIXYBAR. (M.E.L.) [es

  14. Operation and maintenance of the RA reactor, RA Research reactor. Annual report 1976; Pogon i odrzavanje reaktora RA, Izvestaj o radu u 1976. godini

    Energy Technology Data Exchange (ETDEWEB)

    Martinc, R [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1976-12-15

    During 1976 the Ra reactor was operating for about 30% shorter period than usual. The reason were extraordinary repair activities within regular and investment maintenance as well as repair of failures caused by neglected maintenance during previous 6 years. Delay was caused by unavailability of fuel (2% enriched fuel elements are spent) and the new 80% enriched fuel demanded experimental and theoretical analyses before being introduced into the core. Safety analyses concerned with using 80% enriched fuel both experimental and theoretical were successfully fulfilled. The December 1976 successful experimental campaign can be marked as end of the 17 years period of using 2% enriched fuel and start of the new period of using highly enriched fuel. This is significant not only for the reactor itself but for the users, because it would result in increase of neutron flux by 50% with the increase of costs by only 4%. Demand was submitted for obtaining the final license for transition operating regime with highly enriched fuel which would save at least 2 200 000 dinars. This will enable reactor operation in 1977 and later on, without interruption by 'critical' and other experiments related to new highly enriched fuel. A high number of repair and other urgent activities were fulfilled in order to enable safe operation. Some of these activities were done never before and some were neglected during past 6 years. The most important tasks were: purchase of Al tubes made of special alloy, fabrication and mounting of the fuel channel; overall investigation of reactor vessel leakage; repair of the heavy water pump; exchange of two vertical channels. basic equipment for construction of emergency cooling system was purchased. Hot cells are equipped for independent utilisation. [Serbo-Croat] Reaktor RA je u 1976. godini radio za oko 30% krace vreme od uobicajenog. Razlog su bill izuzetno veliki obim remontnih i drugih radova u okviru tekuceg i investicionog odrzavanja, kao i krupnih

  15. Power measurement of the RA-3 reactor using the neutron noise technique and 16N

    International Nuclear Information System (INIS)

    Gomez, Angel

    2003-01-01

    This work describes a measurement method based on the neutron noise technique which is used for determining the relation between the power and the currents of two ionization chambers. These chambers are sensitive to the gamma radiation from the 16 N decay produced in the RA-3 reactor core. The power during operation is obtained from the calibration factors by measuring those currents. As this calibration factors depend on the cooler flow that circulates in the reactor core and in the 16 N measuring system, an estimator, that is a function of the ratio of this currents, is proposed in order to detect flow changes. (author)

  16. Measurements of neutron flux in the RA reactor; Merenje karakteristika neutronskog fluksa u reaktoru RA

    Energy Technology Data Exchange (ETDEWEB)

    Raisic, N [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1961-12-15

    This report includes results of the following measurements performed at the RA reactor: thermal neutron flux in the experimental channels, epithermal and fast neutron flux, neutron flux in the biological shield, neutron flux distribution in the reactor cell.

  17. Conclusions of the experts group of the RA reactor at the meeting held on November 2 and 3 1964 - Annex 12a

    International Nuclear Information System (INIS)

    Pavicevic, M.

    1964-01-01

    Conclusions of the experts group of the RA reactor are related to: analyses of reactor operation at 6.5 MW power with heavy water coolant flow of 250 m 3 /h (2 pumps rotation speed 1500 rotations/min); decisions of future operation; further preparation activities related to reactor operation in forced regime and reduced cooling conditions

  18. IV Training program for the staff of the laboratory for the RA reactor exploitation; IV Programi obuke osoblja Laboratorije za eksploataciju reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1960-07-01

    All the staff members of the laboratory for RA reactor exploitation are obliged to learn the following: fundamental properties of the RA reactor, the role and functionality of the reactor components, basic and auxiliary reactor systems, basics of radioactivity, measures for preventing contamination. The personnel working in shifts must be acquainted with the regulations and instructions for reactor operation. Training programs for reactor operators, mechanics, electricians, instrumentators and dosimetrysts are described separately. Svi saradnici Laboratorije za eksploataciju reaktora RA moraju poznavati sledece oblasti: Osnovne karakeristike reaktora RA, princip rada, ulogu i funkcionisanje komponenti reaktora, osnovnih i pomocnih sistema reaktora; osnovne pojmove o radioaktivnom zracenju, mere za sprecavanje kontaminacije. Osoblje koje radi u smenama mora dodatno poznavati propise i uputstva za rad reaktora. Posebno je naveden program obuke operatora reaktora, mehanicara, electricara, instrumentatora, dozimetrista.

  19. RA research reactor - potentials and prospective

    International Nuclear Information System (INIS)

    Sotic, O.

    1984-01-01

    Since December 1959, the RA reactor was operated successfully, except for a few shorter periods needed for maintenance and a four longer shutdown periods caused by decrease in the heavy water quality. Accordingly, reconstruction of some reactor systems was started at the beginning of this decad, as well as increase of its experimental potential which would enable its efficient reliable operation in the future period. Reconstruction is concerned with emergency core cooling system, special ventilation system, and modernization of the reactor instrumentation. Improvement of the experimental potential is related to modifications of the neutron scattering instruments. Development of methods for isotope production is described as well. Design of the reactor experimental loop with external cooling system will be of significant importance in improvement of reactor potential in the future

  20. Research nuclear reactor RA - Annual Report 1990 with the comparative evaluation for the period 1986-1990

    International Nuclear Information System (INIS)

    Sotic, O.

    1990-12-01

    Annual report concerning the project 'RA research nuclear reactor' for 1990, financed by the Serbian ministry of science is divided into two parts. First part is concerned with RA reactor operation and maintenance, which is the task of the Division for reactor engineering of the Institute for multidisciplinary studies and RA reactor engineering. Second part deals with radiation protection activities at the RA reactor which is the responsibility of the Institute for radiation protection. Scientific council of the Institute for multidisciplinary studies and RA reactor engineering has stated that this report describes adequately the activity and tasks fulfilled at the RA reactor in 1989. The scope and the quality of the work done were considered successful both concerning the maintenance and reconstruction, as well as radiation protection activities [sr

  1. RA Research nuclear reactor, Part I - RA nuclear reactor operation, maintenance and utilization in 1984

    International Nuclear Information System (INIS)

    Sotic, O.; Martinc, R.; Cupac, S.; Sulem, B.; Badrljica, R.; Majstorovic, D.; Sanovic, V.

    1984-12-01

    During the 1984 the reactor operation was limited by the temporary operating license issued by the Committee of Serbian ministry for health and social care. The reason was the non existing emergency cooling system and lack of appropriate filters in the special ventilation system. This temporary license has limited the reactor power to 2 MW from 1981. Operation of the primary cooling system was changed in order to avoid appearance of the previously noticed aluminium oxyhydrate on the surface of the fuel element claddings. The new cooling regime enabled more efficient heavy water purification. Control and maintenance of the reactor instrumentation and tools was done regularly but dependent on the availability of the spare parts. In order to enable future reliable operation of the RA reactor, according to new licensing regulations, during 1984, three major tasks are planned: building of the new emergency system, reconstruction of the existing ventilation system, and renewal of the reactor instrumentation. Financing of the planned activities will be partly covered by the IAEA. this Part I of the report includes 8 Annexes describing in detail the reactor operation, and 6 special papers dealing with the problems of reactor operation and utilization

  2. RA Research reactor, Part 1, Operation and maintenance of the RA nuclear reactor for 1988

    International Nuclear Information System (INIS)

    Sotic, O.; Martinc, R.; Cupac, S.; Sulem, B.; Badrljica, R.; Majstorovic, D.; Sanovic, V.

    1988-01-01

    According to the action plan for 1988, operation of the RA reactor should have been restarted in October, but the operating license was not obtained. Control and maintenance of the reactor components was done regularly and efficiently dependent on the availability of the spare parts. The major difficulty was maintenance of the reactor instrumentation. Period of the reactor shutdown was used for repair of the heavy water pumps in the primary coolant loop. With the aim to ensure future safe and reliable reactor operation, action were started concerning renewal of the reactor instrumentation. Design project was done by the soviet company Atomenergoeksport. The contract for constructing this equipment was signed, and it is planned that the equipment will be delivered by the end of 1990. In order to increase the space for storage of the irradiated fuel elements and its more efficient usage, projects were started concerned with reconstruction of the existing fuel handling equipment, increase of the storage space and purification of the water in the fuel storage pools. These projects are scheduled to be finished in mid 1989. This report includes 8 annexes concerning reactor operation, activities of services and financial issues [sr

  3. RA Research reactor, Part I: Technical and operational properties of the RA reactor; Analiza sigurnosti rada Reaktora RA I-III, Deo I: Tehnicke i pogonske karakteristike reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

    Raisic, N; Zecevic, V; Nikolic, M; Popovic, B; Milosevic, M; Milic, M; Strugar, P; Pesic, M; Nikolic, V; Rajic, M; Radivojevic, J; Jankovic, M [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1963-02-15

    RA reactor is a research reactor with rather high power density. Apart from research it is used for isotope production and industrial applications due to high reactivity excess (about 11%). It is a thermal reactor, heavy water moderated, cooled by D{sub 2}O, and H{sub 2}O, with a graphite reflector. Nominal power is 6.5 MW. Fuel is 2% enriched metal uranium, reactor core height is 1220 mm, and diameter is 1405 mm. Reactor lattice is square with lattice pitch 130 mm. There is 6 horizontal experimental channels and a graphite column. There is a total of 84 fuel channels and 45 experimental channels in the core. Maximum thermal neutron flux is 5.5 10{sup 13} n/cm{sup 2} s at nominal power level.

  4. Safety analysis of RA reactor operation, I-II, Part I - RA reactor technical and operation characteristics; Analiza sigurnosti rada reaktora RA - I-III, I deo - Tehnicke i pogonske karakteristike reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

    Raisic, N [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1963-02-15

    RA research reactor is a thermal, heavy water moderated system with graphite reflector having nominal power 6.5 MW. The 2% enriched metal uranium fuel in the reactor core produces mean thermal neutron flux of 2.9 10{sup 13} neutrons/cm{sup 2} s, and maximum neutron flux 5.5 10{sup 13} neutrons/cm{sup 2} s. main components of the reactor described in this report are: rector core, reflector, biological shield, heavy water cooling system, ordinary water cooling system, helium system, reactor control system, reactor safety system, dosimetry system, power supply system, and fuel transport system. Detailed reactor properties and engineering drawings of all the system are part of this volume.

  5. Conclusions of the experts group of the RA reactor at the meeting held on November 2 and 3 1964 - Annex 12a; Prilog 12a - Zakljucci sa sastanka Strucnog kolegijuma reaktora RA odrzanog na dan 2. i 3. novembra 1964. godine

    Energy Technology Data Exchange (ETDEWEB)

    Pavicevic, M [Institute of Nuclear Sciences Boris Kidric, Reaktor RA, Vinca, Beograd (Serbia and Montenegro)

    1964-12-15

    Conclusions of the experts group of the RA reactor are related to: analyses of reactor operation at 6.5 MW power with heavy water coolant flow of 250 m{sup 3}/h (2 pumps rotation speed 1500 rotations/min); decisions of future operation; further preparation activities related to reactor operation in forced regime and reduced cooling conditions.

  6. Safety analysis of an irradiation device for 99Mo production in RA-3 reactor

    International Nuclear Information System (INIS)

    Lerner, Ana Maria; Madariaga, Marcelo; Waldman, Ricardo

    2000-01-01

    The Argentine RA-3 research reactor (5 MW) has been converted to LEU fuel more than nine years ago. Since then, it has been operating with LEU fuel, which has been designed and fabricated at the National Atomic Energy Commission (CNEA). The Nuclear Regulatory Authority (ARN) is the institution in charge of the installation safety control. It is under this framework that the ARN has elaborated a neutronic calculation model for the RA-3 core, paying special attention to the device presently used for the irradiation of (HEU) 235 U targets required to obtain 9 '9Mo as a fission product. A regulatory analysis of results is carried out in the framework of ARN standards for fixed experiments. For such purpose, calculated reactivity values associated with such device are compared with recently measured values at the installation. Finally, and according to guidelines established in the first part of this work, a calculation model for a new device proposed by CNEA for the irradiation of metallic (LEU) uranium targets and still at its design stage, is here analysed. (author)

  7. Nuclear Reactor RA Safety Report, Vol. 13, Causes of possible accidents

    International Nuclear Information System (INIS)

    1986-11-01

    This volume includes the analysis of possible accidents on the RA research reaktor. Any unwanted action causing decrease of integrity of any of the reactor safety barriers is considered to be a reactor accident. Safety barriers are: fuel element cladding, reactor vessel, biogical shield, and reactor building. Reactor accidents can be classified in four categories: (1) accidents caused by reactivity changes; (2) accidents caused by mis function of the cooling system; (3) accidents caused by errors in fuel management and auxiliary systems; (4) accidents caused by natural or other external disasters. The analysis of possible causes of reactor accidents includes the analysis of possible impacts on the reactor itself and the environment [sr

  8. RA reactor action plan for 1977 - Annex VI; Prilog VI - Plan rada reaktora RA za 1977. godinu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1976-12-15

    In the RA reactor action plan for 1977 it is foreseen that the reactor would be operated for 181 days, mostly at nominal power of 6.5 MW. It is planned to produce 28236 MWh in total. Five reactor core exchanges (refuelling) are planned. The plan includes time for repair of components as well as for cooling. [Serbo-Croat] Plan rada reaktora RA predvidja rad tokom 181 dana, vecim delom na nominalnoj snazi od 6,5 MW tokom 1977. godine. Planirano je da ukupni rad iznosi 28236 MWh. Planom je predvidjeno i pet izmena goriva kao i vreme potrebno za remont opreme i hladjenje.

  9. Nuclear Reactor RA Safety Report, Format and Contents

    International Nuclear Information System (INIS)

    1986-11-01

    This is a new complete version of the safety report of nuclear reactor RA is made according to the recommendations of the IAEA. Report includes all the relevant data needed for evaluation of safe operation of this nuclear facility. Each of seven volumes of this report cover separate topics as follows: (1) introduction; (2) Site characteristics; (3) description of the reactor building and installations; (4) description of the reactor; (5) description of the coolant system; (6) description of the regulation and safety instrumentation; (7) description of the power supply system; (8) description of the auxiliary systems; (9) radiation protection issues; (10) radioactive waste management (11) reactor operation; (12) accident analysis during previous operation; (13) analysis of possible accident causes; (14) safety analysis and preventive actions: (15) analysis of significant accidents; (16) analysis of maximum possible accident; (17) environmental impact analysis in case of accident [sr

  10. Tasks related to increase of RA reactor exploitation and experimental potential, 03. Crane for handling the vertical experimental channels of the RA reactor - design project; Radovi na povecanju eksploatacionih i eksperimentalnih mogucnosti reaktora RA, 03. Kran za opsluzivanje vertikalnih eksperimentalnih kanala reaktora RA - izrada projekta

    Energy Technology Data Exchange (ETDEWEB)

    Pavicevic, M [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1963-07-15

    Within the work related to improvement of experimental potential of the RA reactor, this document describes the design project of the new crane for handling the vertical experimental channels of the RA reactor, engineering drawings of the crane main elements, mechanical part, design project of the electrical part of the crane and cost estimation.

  11. Calculation of neutron spectra in the reactor cell of the RA experimental reactor in Vinca

    International Nuclear Information System (INIS)

    Bosevski, T.; Altiparmakov, D.; Marinkovic, N.

    1974-01-01

    In the frame of neutron properties of RA experimental reactor the study of energy neutron spectra in the reactor cell are planned. Complex reactor cell geometry, nine cylindrical regions causes high space-energy variations of neutron flux with a significant gradient both in energy and space variables. Treatment of such a complex problem needs adequate methodology which ensures reliable results and control of accuracy. This paper describes in detail the method for calculating group constants based on lattice cell calculation for the need of calculation of reactor core parameters. In 26 group approximation for the energy region from 0 - 10.5 MeV, values of neutron spectra are obtained in 18 space points chosen to describe, with high accuracy, integral reactor cell parameters of primary importance for the reactor core calculation. Obtained space-energy distribution of neutron flux in the reactor cell is up to now unique in the study of neutron properties of Ra reactor [sr

  12. Chemical dosimetry at the RA reactor; Hemijska dozimetrija reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

    Gal, O [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1961-12-15

    This report presents the results of measurements of absorbed doses axial and radial distribution in the vertical experimental channels of the RA reactor. Measurements were done in channels VK-5, VK-7, VK-9 and GF-36. Results were compared to the results of calorimetry measurements and measured neutron flux values performed by other laboratories. Fricke and oxalate dosemeters were used in addition to the cobalt indicators.

  13. Waste Management During RA Reactor Decommissioning

    International Nuclear Information System (INIS)

    Markovic, M.; Avramovic, I.

    2008-01-01

    The objective of radioactive waste management during the RA reactor decommissioning is to deal with radioactive waste in a manner that protects human health and the environment now and in the future. The estimation of waste quantities to be expected during decommissioning is a very important step in the initial planning. (author)

  14. The RA nuclear research reactor at VINCA Institute as an engineering and scientific challenge

    International Nuclear Information System (INIS)

    Mesarovic, M.

    1997-01-01

    The RA nuclear research at the Vinca Institute of Nuclear Sciences is the largest nuclear research facility in Yugoslavia and belongs to that generation of research reactors which have had an important contribution to nuclear technology development. As these older reactors were generally not built to specific nuclear standards, new safety systems had to be installed at the RA reactor for a renewal of its operating licence in 1984 and it was shut down, after 25 years of operation. Although all the required and several additional systems were built for the restart of the RA reactor, a disruption of foreign delivery of new control equipment caused its conversion to a 'dormant' facility, and it is still out of operation. Therefore, the future status of the RA reactor presents an engineering and scientific challenge to the engineers and scientists from Yugoslavia and other countries that may be interested to participate. To attract their attention on the subject, principal features of the RA reactor and its present status are described in detail, based on a recent engineering economic and safety evaluation. A comparative review of the world research reactors is also presented.(author)

  15. Decommissioning strategy for the 'RA' research nuclear reactor at the 'Vinca' Institute

    International Nuclear Information System (INIS)

    Matausek, M.V.

    2000-01-01

    Adopting the global strategy for decommissioning of the research reactor RA at the Vinca Institute and preliminary planning of particular activities is necessary independently on the decision of the future status of this reactor, namely even in the case that it is decided to complete the modernization and to use the reactor again. In this paper the global decommissioning strategy for the RA reactor is proposed, as well as the optimal time schedule of particular activities, based on the relevant experiences from other countries (author) [sr

  16. Research nuclear reactor RA - Annual Report 1995, with comparative review for period 1991-1995

    International Nuclear Information System (INIS)

    Sotic, O.

    1995-12-01

    Activities related to revitalisation of the RA reactor started in 1986, were continued during period 1991-1995. All the planned actions related to renewal of the reactor components were finished. The last, and at the same time most important action, related to exchange of complete reactor instrumentation is underway, delayed. The delivery of components from USSR is late. Production of this instruments is financed by the IAEA according to the contract signed in December 1988 with Russian Atomenergoexport. According to this contract, it has been planned that the RA reactor instrumentation should be delivered to the Vinca Institute by the end of 1990. Only 56% of the instrumentation was delivered until September 1991. Since then any delivery of components to Yugoslavia was stopped because of the temporary embargo imposed by the IAEA. The existing RA reactor instrumentation was dismantled. Control and maintenance of the reactor components was done regularly and efficiently. Fuel inspection by the IAEA safeguards inspectors was done on a monthly basis. There have been on the average 47 employees at the RA reactor which is considered sufficient for maintenance and repair conditions. The problem of financing the reactor activities and maintenance remains unsolved during the period 1991-1995. This research reactor RA Annual is divided into two main parts to cover: (1) operation and maintenance and (2) activities related to radiation protection [sr

  17. Regulations and instructions for RA reactor operation

    International Nuclear Information System (INIS)

    1989-01-01

    This regulatory guide consists of following 4 chapters: Description of the RA reactor, organization scheme, regulations for performing experiments; Regulations for staff on duty; Instructions for operating the vacuum systems, heavy water and helium systems; and evacuation in case of accident [sr

  18. Research nuclear reactor RA - Annual report 1992

    International Nuclear Information System (INIS)

    Sotic, O.

    1992-12-01

    Research reactor RA Annual report for year 1992 is divided into two main parts to cover: (1) operation and maintenance and (2) activities related to radiation protection. First part includes 8 annexes describing reactor operation, activities of services for maintenance of reactor components and instrumentation, financial report and staffing. Second annex B is a paper by Z. Vukadin 'Recurrence formulas for evaluating expansion series of depletion functions' published in 'Kerntechnik' 56, (1991) No.6 (INIS record no. 23024136. Second part of the report is devoted to radiation protection issues and contains 4 annexes with data about radiation control of the working environment and reactor environment, description of decontamination activities, collection of radioactive wastes, and meteorology data [sr

  19. Radiation protection at the RA Reactor in 1984, Part -2, Annex 2a: Radioactivity control of the RA reactor environment - atmospheric precipitations, dust, water, soil, plants, fruit.

    International Nuclear Information System (INIS)

    Ajdacic, N.; Martic, M.; Jovanovic, J.

    1984-01-01

    Control of radioactivity in the biosphere in the vicinity of the RA reactor is part of the radioactivity control done regularly for the whole territory of the Vinca institute. During 1984 control was conducted according to the plan. According to the measured data no significant changes have been found in the surroundings of the RA reactor. All the analysed samples have followed the activity values of the precipitations

  20. Design study of eventual core conversion for the research reactor RA

    International Nuclear Information System (INIS)

    Matausek, M. V.; Marinkovic, N.

    1998-01-01

    Main options are specified for the future status of the 6.5 MW heavy water research reactor RA. Arguments pro and contra restarting the reactor are presented. When considering the option to restart the RA reactor, possibilities to improve its neutronic parameters, such as neutron flux values and irradiation capabilities are discussed, as well as the compliance with the worldwide activities of Reduced Enrichment for Research and Test Reactors (RERTR) program. Possibility of core conversion is examined. Detailed reactor physics design calculations are performed for different fuel types and uranium loading. For different fuel management schemes results are presented for the effective, multiplication factor, power distribution, fuel burnup and consumption. It is shown that, as far as reactor core parameters are considered, conversion to lower enrichment fuel could be easily accomplished. However, conversion to the lower enrichment could only be justified if combined with improvement of some other reactor attributes. (author)

  1. Research nuclear reactor RA - Annual Report 1975. Operation and maintenance; Istrazivacki nuklearni reaktor RA - Izvestaj za 1975. godinu - Pogon i odrzavanje

    Energy Technology Data Exchange (ETDEWEB)

    Martinc, R [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1976-01-15

    The plan for 1975 was successfully fulfilled. This is reflected in research related to improvement of operating properties of the RA reactor, mostly due to the effort of the RA staff employed in operation and maintenance of the reactor. Fuel saving achieved by this activity amounted to about 38% (80% enriched fuel). Preliminary work is done, concerned with new reactor core with highly enriched fuel. This is a significant saving as well. New fuel elements have arrived at the end of this year. It is going to enable increase of neutron flux by 50% without changing the nominal operating power. The possibility of further improvement of the reactor are analyzed, to enable material testing and production of radioactive sources. Mid term plan for reactor operation was made according to this analysis. It is planned to further increase the neutron flux in isolated smaller zones, and building new experimental loops with cooling and fast neutron converters. Much was done to increase the safety level of reactor operation and preparing the safety report. [Serbo-Croat] Izvrsenje zadataka u 1975. godini bilo je uspesno. To se ogleda u povecanju istrazivackog rada vezanog za poboljsanje eksploatacionih karakteristika reaktora RA, pretezno koriscenjem sopstvenog kadra angazovanog u pogonu i odrzavanju reaktora. Ovim radom postignuta je usteda goriva od oko 38% (80% obogaceno gorivo). Izvrseni su preliminarni radovi na prevodjenju reaktora RA na novo gorivo, sto je takodje velika usteda. Novo gorivo je stiglo krajem godine i ono ce obezbediti porast neutronskog fluksa od 50%, bez promene nominalne snage reaktora. Izvrsena je analiza mogucnosti daljeg usavrsavanja reaktora za potrebe ispitivanja materijala kao i proizvodnju radioaktivnih izvora. Na osnovu ove analize nacinjen je srednjorocni program rada reaktora RA sa tezistem na daljem povecanju fluksa u izdvojenim manjim zonama i ugradnju 'hladjenih petlji' i brzih konvertora. Mnogo je ucinjeno na povecanju stepena sigurnosti

  2. RA reactor kinetic parameters - Progress report; Kineticki parametri reaktora RA - Izvestaj o napredovanju -

    Energy Technology Data Exchange (ETDEWEB)

    Petrovic, M; Obradovic, D; Jevtovic, V; Velickovic, Lj [Institute of nuclear sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

    1965-11-15

    The objective of nuclear reactor kinetics study is to analyze the stability of reactor operation in practice. The obtained parameters should define the needed properties of automatic control system relevant for the stability of the designed reactor system. Refining the analytical models is done by using the analysis and interpretation of experimental data. Results of measured the reactor response obtained by using the reactor oscillator ROB-1 are explained by using the space independent model of the zero power reactor, by power reactor model with one feedback circuit, and by a complex model. It was assumed that the perturbations of the system are small and that linearized kinetic equations could be used. Linearized kinetic equation of the reactor system are transformed into the frequency region in order to analyze the measured values directly. The objective of this paper is to measure the RA reactor kinetics parameters, and analyze the stability of reactor operation at power levels high than nominal. Istrazivanja u oblasti kinetike nuklearnih reaktora imaju za cilj da dovedu analizu stabilnosti rada reaktora na nivo 'radne tehnologije'. Dobijeni pararametri treba da specificiraju potrebne karakteristike sistema automatske kontrole za odgovarajucu stabilnost projektovanog reaktorskog sistema. Doterivanjem analitickih modela do takvog nivoa da se zapazeni fenomeni mogu anailitcki predvideti ide preko analize i interpretacije eksperimentalnih podataka. Eksperimentalni rezultati merenja odziva reaktora, izvedeni reaktorskim oscilatorom ROB-1, interpretirani su na osnovu prostorno nezavisnog modela za reaktor nulte snage, modelom reaktora snage sa jednim kolom povratne sprege, kao i kompleksnim modelom. U ovom radu se poslo od toga da su perturbacije parametara sistema male, pa se mogu upotrebiti linearizovane kineticke jednacine. Linearizovane kineticke jednacine reaktorskog sistema transformirane su u frekventno podrucje s ciljem direktne analize mernih rezultata

  3. RA research reactor - properties and experimental capabilities; Istrazivacki reaktor RA - Tehnicke karakteristike i eksploatacione mogucnosti

    Energy Technology Data Exchange (ETDEWEB)

    Milosevic, M; Martinc, R [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1978-05-15

    The brief survey of the Reactor RA exploitation experience, as well as the reactor equipment state, after 18 years of operation is presented. The results of efforts spent on reactor characteristics improvement in order to ensure safe and reliable reactor operation for next 15-20 years, are described. Prikazani su fragmenti iz eksploatacije reaktora kao i stanje opreme, posle 18 godina rada. Na kraju je dat prikaz sta je preduzeto i sta se preduzima da se poboljsaju karakteristike i poveca sigurnost i bezbednost rada za sledecih 15-20 godina.

  4. Safety analysis of RA Reactor operation I-III; Analiza sigurnosti rada Reaktora RA I - III, IZ-213-0322-1963

    Energy Technology Data Exchange (ETDEWEB)

    Raisic, N [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1963-02-15

    This safety analysis report covers the following three parts: Technical and operational characteristics of the RA reactor; Accidents analysis; and Environmental effects of the maximum possible accident. [Serbo-Croat] Ovaj izvestaj o analizi sigurnosti rada reaktora RA sastoji se od tri dela: Tehnicke i pogonske karakteristike reaktora RA; Analiza akcidenta; i Posledice maksimalno moguceg akcidenta na okolinu reaktora.

  5. RA reactor operation and maintenance, Annual report 1974

    International Nuclear Information System (INIS)

    Milosevic, D. et al

    1974-12-01

    During 1974, RA reactor was operated at nominal power for 194 days and 13 days at lower power levels. The total production was 30711 MWh which is 2.4% higher than planned. Practically there were no discrepancies from the plan. The reactor was used for irradiation and experiments according to the demand of 437 users. This report contains detailed data about reactor power and experiments performed in 1974. Total number of afety shutdowns was 11, of which 8 were caused by power cuts, and 3 due to human error. Maximum individual personnel exposure dose was 50% of the maximum permissible dose. There were no accidents during this year. Decontamination of surfaces was less than during previous years. About 805 m 2 of surfaces and 178 objects were decontaminated. It was concluded that the successful operation in 1974 has a special significance taking into account the financial problems [sr

  6. Research nuclear reactor RA - Annual Report 1975. Operation and maintenance

    International Nuclear Information System (INIS)

    Martinc, R.

    1976-01-01

    The plan for 1975 was successfully fulfilled. This is reflected in research related to improvement of operating properties of the RA reactor, mostly due to the effort of the RA staff employed in operation and maintenance of the reactor. Fuel saving achieved by this activity amounted to about 38% (80% enriched fuel). Preliminary work is done, concerned with new reactor core with highly enriched fuel. This is a significant saving as well. New fuel elements have arrived at the end of this year. It is going to enable increase of neutron flux by 50% without changing the nominal operating power. The possibility of further improvement of the reactor are analyzed, to enable material testing and production of radioactive sources. Mid term plan for reactor operation was made according to this analysis. It is planned to further increase the neutron flux in isolated smaller zones, and building new experimental loops with cooling and fast neutron converters. Much was done to increase the safety level of reactor operation and preparing the safety report [sr

  7. Removal of spent fuel from the TVR reactor for reprocessing and proposals for the RA reactor spent fuel handling

    International Nuclear Information System (INIS)

    Volkov, E.B.; Konev, V.N.; Shvedov, O.V.; Bulkin, S.Yu; Sokolov, A.V.

    2002-01-01

    The 2,5 MW heavy-water moderated and cooled research reactor TVR was located at the Moscow Institute for Theoretical and Experimental Physics site. In 1990 the final batch of spent nuclear fuel (SNF) from the TVR reactor was transported for reprocessing to Production Association (PA) 'Mayak'. This transportation of the SNF was a part of TVR reactor decommissioning. The special technology and equipment was developed in order to fulfill the preparation of TVR SNF for transportation. The design of the TVR reactor and the fuel elements used are similar to the design and fuel elements of the RA reactor. Two different ways of RA spent fuel elements for transportation to reprocessing plant are considered: in aluminum barrels, and in additional cans. The experience and equipment used for the preparing TVR fuel elements for transportation can help the staff of RA reactor to find the optimal way for these technical operations. (author)

  8. Nuclear Reactor RA Safety Report, Vol. 9, Radiation protection

    International Nuclear Information System (INIS)

    1986-11-01

    Instrumentation for Radiation protection existing at the RA reactor is dating mostly from the period 1957-1959 when the reactor has been built. With some minor exception it was produced in USSR. Radiation protection system was constructed based on specific design project, somewhat modified original USSR project which has been indispensable because of some modification of the building design. During the past 27 years no renewal of the instrumentation was done, only maintenance was performed. Instrumentation consists of old electronic devices which caused difficulties and even prevented regular maintenance because of lack of spare parts. Instrumentation for radiation protection at the RA reactor is classified as follows: centralized dosimetry system; stationary dosimetry instrumentation, movable and personal dosimetry systems. Apart from the scheme of dosimetry instrumentation this volume includes description of radiation protection procedures; protection devices; radiation doses and dose limit data; program for environmental radioactivity control; medical control procedures [sr

  9. Optimum RA reactor fuelling scheme

    International Nuclear Information System (INIS)

    Strugar, P.; Nikolic, V.

    1965-10-01

    Ideal reactor refueling scheme can be achieved only by continuous fuel elements movement in the core, which is not possible, and thus approximations are applied. One of the possible approximations is discontinuous movement of fuel elements groups in radial direction. This enables higher burnup especially if axial exchange is possible. Analysis of refueling schemes in the RA reactor core and schemes with mixing the fresh and used fuel elements show that 30% higher burnup can be achieved by applying mixing, and even 40% if reactivity due to decrease in experimental space is taken into account. Up to now, mean burnup of 4400 MWd/t has been achieved, and the proposed fueling scheme with reduction of experimental space could achieve mean burnup of 6300 MWd/t which means about 25 Mwd/t per fuel channel [sr

  10. RA reactor safety analysis, Part II - Accident analysis; Analiza sigurnosti rada Reaktora RA I-III, Deo II - Analiza akcidenta

    Energy Technology Data Exchange (ETDEWEB)

    Raisic, N; Radanovic, Lj; Milovanovic, M; Afgan, N; Kulundzic, P [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1963-02-15

    This part of the RA reactor safety analysis includes analysis of possible accidents caused by failures of the reactor devices and errors during reactor operation. Two types of accidents are analyzed: accidents resulting from uncontrolled reactivity increase, and accidents caused by interruption of cooling.

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

    International Nuclear Information System (INIS)

    Matausek, M.V.; Vukadin, Z.; Pavlovic, S.; Maksin, T.; Idakovic, Z.; Marinkovic, N.

    1997-05-01

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

  12. Determination of the boron content in polyethylene samples using the reactor Orphée

    CERN Document Server

    Gunsing, F; Aberle, O

    2017-01-01

    The boron content of two unknown types of polyethylene has been determined relative to a known reference type. Samples of polyethylene, including a known boron-less one, were irradiated with thermal neutrons at the reactor Orphée at Saclay in France. Prompt gamma rays were measured with a CeBr$_3$ detector and the intensity of the 478~keV line from $^{10}${B}(n,$\\alpha_1\\gamma$)$^{7}{Li*} was extracted.

  13. Basis for calculating boron dilution scenarios in PWR by 3D neutron kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Pla, P., E-mail: patricia_pla@hotmail.com [Univ. of Pisa, San Piero a Grado Nuclear Research Group (GRNSPG), Pisa (Italy); Tech. Univ. of Catalonia, Barcelona (Spain); Parisi, C., E-mail: c.parisi@ing.unipi.it [Univ. of Pisa, San Piero a Grado Nuclear Research Group (GRNSPG), Pisa (Italy); Galetti, R., E-mail: regina@cnen.gov.br [National Commission for Nuclear Energy (CNEN), Rio de Janeiro (Brazil); D' Auria, F.; Galassi, G., E-mail: f.dauria@ing.unipi.it, E-mail: g.galassi@ing.unipi.it [Univ. of Pisa, San Piero a Grado Nuclear Research Group (GRNSPG), Pisa (Italy); Reventos, F., E-mail: francesc.reventos@upc.edu [Tech. Univ. of Catalonia, Barcelona (Spain)

    2011-07-01

    The origin of the performed study was the analysis of 20 cm{sup 2} small break LOCA in the lower plenum in a four-loop PWR nuclear reactor by Relap5 code stand-alone (0DNK) in which boron dilution was observed in more than one loop seal. In order to have a more precise result of the boron dilution NK feedback effect, the original nodalization was refined axially in the core area to couple with PARCS v.2.7 code (3DNK). The neutron macroscopic XSec database was generated by the lattice transport code HELIOS. Before using the new model to predict boron dilution transients, a necessary activity is the qualification of the model (the boron feedback calculated by the Neutronic Cross Sections) against boron changes, so a group of sensitivity calculations injecting more or less borated water in the cold leg were performed either with Relap5 code stand-alone (0DNK) and with Relap5 coupled with PARCS v.2.7 (3DNK) code in order to analyze the reactor power response to the boron injection and the differences using a 0DNK or a coupled 3DNK nodalization. To complete the study a benchmark calculation was performed considering a 20 cm{sup 2} break in the lower plenum, in which the reactor trip by control rods has been disabled and boron injection was simulated in the cold leg. This calculation utilized the Relap5 code stand-alone (0DNK) and the Relap5 coupled with PARCS v.2.7 (3DNK) code, in order to see the differences using a 0DNK or a coupled 3DNK model. Non negligible differences have been found in all cases in the comparison of 0DNK and coupled 3DNK results analyzed, in relation to the core power. These results challenge the evaluation of the uncertainties in case of coupled thermalhydraulic-3DNK calculations. A comprehensive evaluation of the relevant uncertainties of the 3D NK TH coupled calculations is needed. (author)

  14. Basis for calculating boron dilution scenarios in PWR by 3D neutron kinetics

    International Nuclear Information System (INIS)

    Pla, P.; Parisi, C.; Galetti, R.; D'Auria, F.; Galassi, G.; Reventos, F.

    2011-01-01

    The origin of the performed study was the analysis of 20 cm 2 small break LOCA in the lower plenum in a four-loop PWR nuclear reactor by Relap5 code stand-alone (0DNK) in which boron dilution was observed in more than one loop seal. In order to have a more precise result of the boron dilution NK feedback effect, the original nodalization was refined axially in the core area to couple with PARCS v.2.7 code (3DNK). The neutron macroscopic XSec database was generated by the lattice transport code HELIOS. Before using the new model to predict boron dilution transients, a necessary activity is the qualification of the model (the boron feedback calculated by the Neutronic Cross Sections) against boron changes, so a group of sensitivity calculations injecting more or less borated water in the cold leg were performed either with Relap5 code stand-alone (0DNK) and with Relap5 coupled with PARCS v.2.7 (3DNK) code in order to analyze the reactor power response to the boron injection and the differences using a 0DNK or a coupled 3DNK nodalization. To complete the study a benchmark calculation was performed considering a 20 cm 2 break in the lower plenum, in which the reactor trip by control rods has been disabled and boron injection was simulated in the cold leg. This calculation utilized the Relap5 code stand-alone (0DNK) and the Relap5 coupled with PARCS v.2.7 (3DNK) code, in order to see the differences using a 0DNK or a coupled 3DNK model. Non negligible differences have been found in all cases in the comparison of 0DNK and coupled 3DNK results analyzed, in relation to the core power. These results challenge the evaluation of the uncertainties in case of coupled thermalhydraulic-3DNK calculations. A comprehensive evaluation of the relevant uncertainties of the 3D NK TH coupled calculations is needed. (author)

  15. Operation and maintenance of the RA reactor; Pogon i odrzavanje reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

    Petrovic, M; Zecevic, V [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1961-12-15

    During 1961 the RA reactor was used for irradiation of samples for 258 users ( from which 188 from the Institute) and for 34 experiments, this means productions of 5958 MWh. The production was almost four times bigger than during previous year due to the demand of the Laboratories of the Institute. Burnup of the fuel from the first batch was about 30%. This means that the operation time could be much higher. Number of safety shut-downs was 11. The reasons were related to electrical faults, 9 occurrences, failure of the instrument for reactor period measurement, once, and failure of the pump once. This report covers state and operation data of the reactor components, control instruments, devices for reactor protection, dosimetry, heavy water system, helium system, mechanical and electrical equipment. Problems related to training of the staff and lack of personnel are mentioned as well.

  16. 40 years after RA-3 inauguration: anecdotes, stories and one or two lessons learned

    International Nuclear Information System (INIS)

    Briozzo, Federico

    2007-01-01

    The Argentine research and production reactor RA-3 was inaugurated in December 1967 to cover the national demand of radioisotopes for medical use, but it was also intended to increase the national capacity in nuclear technology. 'To learn doing' was the predominant spirit that guided its construction. The experience so acquired allowed the design and construction of several other reactors. Today, the RA-3 not only 'lives' at the Ezeiza Atomic Center... but it is also 'alive' in the reactors built by Argentina in Bariloche, Peru, Algeria, Egypt and Australia. (author) [es

  17. RA Reactor operation and maintenance (I-IX), Part II, Task 3.08/04; Pogon i odrzavanje reaktora RA (I-IX), II Deo, Zadatak 3.08/04

    Energy Technology Data Exchange (ETDEWEB)

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

    1963-12-15

    Repair and maintenance work of the RA reactor components and equipment was longer than planned due to the following reasons: chemical decontamination of the reactor heavy water system indispensable for maintenance of the heavy water pumps; findings of contamination origin changed the maintenance schedule; some construction materials of the heavy water pumps which caused contamination had to be removed; a number of the planned operations had to be performed under increase level of gamma radiation which increased the time needed for repair. This report covers detailed description of all the maintenance and repair work done from 25 Jan to 22 Apr 1963.

  18. RA reactor operation in 1991, Part 1; Deo 1 - Pogon i odrzavanje nuklearnog reaktora RA u 1991. godini

    Energy Technology Data Exchange (ETDEWEB)

    Sotic, O; Cupac, S; Sulem, B; Zivotic, Z; Majstorovic, D; Sanovic, V [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1992-01-01

    During the previous period RA reactor was not operated because the Committee of Serbian ministry for health and social care has cancelled the operation licence in August 1984. The reason was the non existing emergency cooling system and lack of appropriate filters in the special ventilation system. Control and maintenance of the reactor instrumentation and tools was done regularly but dependent on the availability of the spare parts. In order to enable future reliable operation of the RA reactor, according to new licensing regulations, during 1991, three major tasks were fulfilled: building of the new emergency cooling system, reconstruction of the existing ventilation system, and renewal of the reactor power supply system. Renewal of the reactor instrumentation was started but but it is behind the schedule in 1991 because the delivery of components from USSR is late. Production of this instruments is financed by the IAEA according to the contract signed in December 1988 with Russian Atomenergoexport. According to this contract, it has been planned that the RA reactor instrumentation should be delivered to the Vinca Institute by the end of 1990. Since then any delivery of components to Yugoslavia was stopped because of the temporary embargo imposed by the IAEA for political reasons. In 1991 most of the existing RA reactor instrumentation was dismantled, only the part needed for basic measurements when reactor is not operated, was maintained. Training of the existing personnel was done regularly, but lack of financial support prevented employment of new workers that would be needed for operation in shifts and regular maintenance. [Serbo-Croat] U proteklom periodu reaktor RA nije bio u pogonu zato sto je 30. jula Republicki komitet za zdravlje i socijalnu politiku republike Srbije, zabranio njegov rad zbog toga sto reaktor ne poseduje sistem za udesno hladjenje i ne poseduje odgovarajuce filtere u sistemu specijalne ventilacije. Kako bi se ubuduce mogao obezbediti

  19. RA reactor operation and maintenance in 1989, Part 1; Deo 1 - Pogon i odrzavanje nuklearnog reaktora RA u 1989. godini

    Energy Technology Data Exchange (ETDEWEB)

    Sotic, O; Martinc, R; Cupac, S; Sulem, B; Zivotic, Z; Majstorovic, D; Sanovic, V [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1989-12-15

    During the previous period RA reactor was not operated because the Committee of Serbian ministry for health and social care has cancelled the operation licence in July 1984. The reason was the non existing emergency cooling system and lack of appropriate filters in the special ventilation system. The following major tasks were fulfilled: building of the new emergency cooling system, reconstruction of the existing ventilation system, and renewal of the power supply system. Project concerned with renewal of RA reactor complete instrumentation was started at the end of 1988. Contract was signed between the IAEA and Soviet Atomenergoexport for supplying the new instrumentation for the RA reactor. Project concerned with increase of the storage space and the efficiency of handling the spent fuel elements has started in 1988. In 1989, device for water purification designed by the reactor staff started operation and spent fuel handling equipment is being mounted. Training of the existing personnel and was done regularly, but the new staff has no practical training since the reactor is not operated. Lack of financial support influenced strongly the status of RA reactor. [Serbo-Croat] U proteklom periodu reaktor RA nije bio u pogonu zato sto je 30. jula 1984. Republicki komitet za zdravlje i socijalnu politiku republike Srbije, zabranio njegov rad zbog toga sto reaktor ne poseduje sistem za udesno hladjenje i ne poseduje odgovarajuce filtere u sistemu specijalne ventilacije. Zavrseni su radovi na izgradnji sistema za udesno hladjenje, rekonstrukciji postojeceg sistema specijalne ventilacije i rekonstrukciji sistema za napajanje elektricnom energijom. Krajem 1988, medjunarodna agencija za atomsku energiju potpisala je ugovor sa sovjetskom firmom Atomergexport za izradu novog sistema instrumentacije. Sa ciljem da se poveca i efikasnije koristi prostor za skladistenje ozracenog goriva, 1987. godine zapoceta je realizacija projekata preciscavanja vode u bazenima za odlezavanje

  20. Diagrams about RA reactor operation, Annex 7; Prilog 7 - Rad reaktora RA po godinama - dijagrami

    Energy Technology Data Exchange (ETDEWEB)

    Martinc, R [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1976-01-15

    This Annex 7 includes diagrams about RA reactor operation (MWh) from 1960-1975; mean values of reactor power per day and month in 1975, and percent of utilisation of experimental space during 1975. [Serbo-Croat] Ovaj prilog sadrzi dijagrame o radu reaktora (MWh) po godinama (1960-1975); srednje vrednosti dnevne snage reaktora u 1975. godini; rad reakrora (MWh) po mesecima u 1975; procenat iskoriscenja eksperimentalnog prostora u 1975. godini.

  1. Feasibility study to restart the research reactor RA with a converted core

    International Nuclear Information System (INIS)

    Matausek, M.V.; Plecas, I.; Marinkovic, N.

    1999-01-01

    Main options are specified for the future status of the 6.5 MW heavy water research reactor RA. Arguments pro and contra restarting the reactor are presented. When considering the option to restart the RA reactor, possibilities to improve its neutronic parameters, such as neutron flux values and irradiation capabilities, are discussed, as well as the compliance with the worldwide activities of Reduced Enrichment for Research and Test Reactors (RERTR) program. Possibility of core conversion is examined. Detailed reactor physics design calculations are performed for different fuel types and uranium loading. For different fuel management schemes results are presented for the effective multiplication factor, power distribution, fuel burnup and consumption. It is shown that, as far as reactor core parameters are considered, conversion to lower enrichment fuel could be easily accomplished. However, conversion to the lower enrichment could only be justified if combined with improvement of some other reactor attributes. (author)

  2. Physical measurements at the RA reactor related to VISA-2, e. Measurements of flux and reactivity during RA reactor operation and exploitation; Fizicka merenja na reaktoru RA u vezi projekta VISA-2, e. Pracenje fluksa i reaktivnosti u toku eksploatacije reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

    Markovic, H [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1963-05-15

    This report includes the following: characteristics of neutron flux in vertical experimental channels of the RA reactor; characteristics of neutron flux in VISA-2 channels; reactivity changes in the reactor during VISA-2 irradiation including calibration of control rods.

  3. RA Research reactor, Report for the period January-December 2002

    International Nuclear Information System (INIS)

    Pesic, M.; Sotic, O.; Nikolic, A.

    2003-01-01

    During 2002 activities at the RA research nuclear reactor were performed according to the action plan related to maintenance of this facility and Contract about financing the reactor for the period January-december 2002 signed in June 2002 with the Ministry of science, technologies and development of the Republic of Serbia. In July 2002. the the Government of Serbia has finally declared a decision about permanent shutdown of the RA reactor, initiation of reactor decommissioning process, and solving the problem of the spent fuel storage in the reactor building. These decisions demanded new organizational structure in the Institute for efficient completion of the mentioned programs. As previously, the main activities during the reporting period involved maintenance of the systems which must be operated permanently or occasionally and the systems and equipment of special importance for security of the facility. In addition to regular maintenance activities, a series of investment tasks were completed in the reactor building. Special activities were related to nuclear fuel inspection conducted by the IAEA. Significant cooperation with IAEA was achieved after September 2001, when Yugoslavia became again a member of the IAEA. During 2002 a number of significant activities were prepared and completed: transport of fresh highly enriched fuel to Russia; signing the contract with IAEA concerning work on future RA reactor decommissioning program; preliminary analysis and preparation for storage of spent nuclear fuel and future decommissioning. The contracts signed with the IAEA are in complete agreement with decisions of the Serbian government. It is indispensable to create a regulatory body on the government level which would provide needed conditions for completion of these complicated tasks and control performance. At this moment no such body exists and no financial support is provided although this is a condition for obtaining support from the IAEA or any other

  4. Nuclear Reactor RA Safety Report, Vol. 12, Accidents during reactor operation

    International Nuclear Information System (INIS)

    1986-11-01

    This volume includes description and analysis of typical accidents occurred during operation of RA reactor in chronological order, as follows: contamination of primary coolant circuit; leakage of heavy water from the primary coolant loop; contamination of vertical experimental channel; air contamination in the reactor building and loss of circulation of the primary coolant; failures of the vacuum pump and spent fuel packaging device; rupture of the spent fuel element cladding; dethronement's of capsule for irradiation of fuel element; rupture of the vertical experimental channel and contamination of the surroundings; swelling of a fuel element; appearance of deposits on the surface of the fuel elements cladding. The last chapter describes similar accidents occurred on nuclear reactors in the world [sr

  5. Operation of the RA research nuclear reactor under forced regime; Rad istrazivackog nuklearnog reaktora RA u forsiranom rezimu

    Energy Technology Data Exchange (ETDEWEB)

    Mitrovic, S [Institut za nuklearne nauke Boris Kidric, Vinca, Beograd (Yugoslavia)

    1964-07-01

    Ra reactor was designed for operation at nominal power of 6.5 MW and under forced regime. From the start of operation in 1959 until the general refurbishment in 1963 it was not operated under forced regime. At reactor power of 10 MW the mean thermal neutron flux increases from 3 to 4.6 10{sup 13} n cm{sup -2} sec{sup -1}, the maximum neutron flux increases from 6 to 9.3 10{sup 13} n cm{sup -2} sec{sup -1}, and at the exit of the experimental channel it increases from 5 to 7.7 10{sup 9} n cm{sup -2} sec{sup -1}. In order to achieve safer and more suitable operating conditions, winter period of 1963 was chosen for the first increase of reactor power level, because of low temperatures in the secondary coolant loop. This paper contains the most relevant data concerned with the reactor operation at increased power.

  6. Modelling of the RA-1 reactor using a Monte Carlo code

    International Nuclear Information System (INIS)

    Quinteiro, Guillermo F.; Calabrese, Carlos R.

    2000-01-01

    It was carried out for the first time, a model of the Argentine RA-1 reactor using the MCNP Monte Carlo code. This model was validated using data for experimental neutron and gamma measurements at different energy ranges and locations. In addition, the resulting fluxes were compared with the data obtained using a 3D diffusion code. (author)

  7. An evaluation of the worker exposure during the RA reactor decommissioning due to presence of contamination

    International Nuclear Information System (INIS)

    Ljubenov, V.; Simovic, R.

    2005-01-01

    In this paper a possibility to establish the relationship between the presence of the surface contamination in the RA reactor rooms and the worker exposure during the decommissioning activities is discussed. RESRAD-BUILD code and the models typical for the RA reactor has been used to determine annual doses from the supposed activities of the main expected RA reactor contaminants. Different room air exchange rates have been modelled and analysed. (author) [sr

  8. Program of RA reactor start-up to nominal power

    International Nuclear Information System (INIS)

    1959-01-01

    The zero start-up program is followed by the program of RA reactor start-up to nominal power. This program is described in detail and includes the following measurements: radiation characteristics at the exit of the channels; gamma and fast neutron dose distribution in the reactor; influence of absorbers on the reactivity; temperature effect; absolute flux and calibration of ionization chambers; xenon effect; thermal and hydraulics; dosimetry around the reactor; neutron flux in the reactor core and in the reactor hall; heavy water level; thermal characteristics after shutdown. A list of measuring devices and instrumentation is included with the detailed action plan and list of responsible staff members

  9. Boiling in the presence of boron compounds in light water reactors

    International Nuclear Information System (INIS)

    Nakath, Richard

    2014-01-01

    The scope of the thesis on boiling in the presence of boron compounds in light water reactors was to study the effects of the boron compound addition on the heat removal from the fuel elements. For an effective cooling of the fuel elements in case of boiling processes a high heat transfer coefficient is of importance. Up to now experimental studies were not performed under reactor specific conditions, for instance with respect to the geometry of the flow conditions, high temperature and pressure levels were not represented. Therefore the experiments in the frame of the thesis were using reactor specific parameters. The test facility SECA (study into the effects of coolant additives) was designed and constructed. The experiments simulated the conditions of normal PWR operation, accidental PWR and accidental BWR conditions.

  10. Research nuclear reactor RA - Annual Report 1990 with the comparative evaluation for the period 1986-1990; Istrazivacki nuklearni reaktor RA - Izvestaj za 1990. godinu uz uporedni pregled za period 1986 - 1990

    Energy Technology Data Exchange (ETDEWEB)

    Sotic, O [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1990-12-15

    Annual report concerning the project 'RA research nuclear reactor' for 1990, financed by the Serbian ministry of science is divided into two parts. First part is concerned with RA reactor operation and maintenance, which is the task of the Division for reactor engineering of the Institute for multidisciplinary studies and RA reactor engineering. Second part deals with radiation protection activities at the RA reactor which is the responsibility of the Institute for radiation protection. Scientific council of the Institute for multidisciplinary studies and RA reactor engineering has stated that this report describes adequately the activity and tasks fulfilled at the RA reactor in 1989. The scope and the quality of the work done were considered successful both concerning the maintenance and reconstruction, as well as radiation protection activities. [Serbo-Croat] Godisnji izvestaj po projektu 'Istrazivacki nuklearni reaktor RA' za 1990. godinu, koji finansira republicka zajednica za nauku SR Srbije po ugovoru br. 3705/1 sastoji se iz dva dela. Prvi deo obuhvata pogon i odrzavanje nuklearnog reaktora RA, sto predstavlja obavezu Odeljenja za reaktorski inzenjering u sastavu OOUR Instituta za multidisciplinarna istrazivanja i inzenjering RA. Drugi deo obuhvata poslove zastite od zracenja na reaktoru RA, sto predstavlja obavezu OOUR Instituta za zastitu od zracenja 'Zastita'. Naucno vece Instituta za multidisciplinarna istrazivanja i inzenjjring RA ocenilo je da sadrzina ovog izvestaja odgovara izvrsenim poslovima na reaktoru RA u 1989. godini. Pozitivno se ocenjuje obim i kvalitet izvrsenih radova kako u pogledu odrzavanja i rekonstrukcije reaktora, tako i u pogledu poslova zastite od zracenja izvrsenih kod njega.

  11. Program of RA reactor start-up to nominal power; Program dizanja reaktora 'RA' na nominalnu snagu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1959-07-01

    The zero start-up program is followed by the program of RA reactor start-up to nominal power. This program is desed in detail and includes the following measurements: radiation characteristics at the exit of the channels; gamma and fast neutron dose distribution in the reactor; influence of absorbers on the reactivity; temperature effect; absolute flux and calibration of ionization chambers; xenon effect; thermal and hydraulics; dosimetry around the reactor; neutron flux in the reactor core and in the reactor hall; heavy water level; thermal characteristics after shutdown. A list of measuring devices and instrumentation is included with the detailed action plan and list of responsible staff members.

  12. Radiation dosimetry of the reactor RA at Vinca, Measurements by isothermal calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Radak, B; Markovic, V; Draganic, I [Institute of nuclear sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1961-12-15

    1. In this work we have made attempts to: - analyze the problems of reactor radiation dosimetry; - describe the solutions of this problem by the calorimetric method; - present our results of measurements of the reactor RA at Vinca, and to describe the method, apparatus and measuring equipment used. 2. Use was made of the isothermal calorimeter with thermistors which measured the absorbed dose rates within the range 10{sup 4}-10{sup 6} rad/h, with an accuracy of 2-5%. It was shown that the reactor radiation in which the thermal neutron flux is up to the order of magnitude 10{sup 12} n/cm{sup 2}/sec, and the integral thermal neutron flux up to about 10{sup 16} n/cm{sup 2} exerts no significant influence upon the working characteristics out of the thermistors used. 3. Determination was made of the absorbed dose distribution into the gamma-ray and the neutron contribution. For this purpose we used 3 materials: ordinary water, heavy water and graphite. 4. Measurements were carried out in two vertical experimental holes 'VK-5' and 'VK-6' of the reactor RA at several heights. It has been shown that the absorbed dose height distribution agrees well with the thermal flux distribution curve, although the relations of the absorbed doses of the two holes are not in accordance with the corresponding thermal flux relations (author)

  13. Radiation dosimetry of the reactor RA at Vinca, Measurements by isothermal calorimeter

    International Nuclear Information System (INIS)

    Radak, B.; Markovic, V.; Draganic, I.

    1961-01-01

    1. In this work we have made attempts to: - analyze the problems of reactor radiation dosimetry; - describe the solutions of this problem by the calorimetric method; - present our results of measurements of the reactor RA at Vinca, and to describe the method, apparatus and measuring equipment used. 2. Use was made of the isothermal calorimeter with thermistors which measured the absorbed dose rates within the range 10 4 -10 6 rad/h, with an accuracy of 2-5%. It was shown that the reactor radiation in which the thermal neutron flux is up to the order of magnitude 10 12 n/cm 2 /sec, and the integral thermal neutron flux up to about 10 16 n/cm 2 exerts no significant influence upon the working characteristics out of the thermistors used. 3. Determination was made of the absorbed dose distribution into the gamma-ray and the neutron contribution. For this purpose we used 3 materials: ordinary water, heavy water and graphite. 4. Measurements were carried out in two vertical experimental holes 'VK-5' and 'VK-6' of the reactor RA at several heights. It has been shown that the absorbed dose height distribution agrees well with the thermal flux distribution curve, although the relations of the absorbed doses of the two holes are not in accordance with the corresponding thermal flux relations (author)

  14. RA Research nuclear reactor, Part I - RA nuclear reactor operation, maintenance and utilization in 1983; Istrazivacki nuklearni reaktor RA - Deo I - Pogon, odrzavanje i eksploatacija nuklearnog reaktora RA u 1983. godini

    Energy Technology Data Exchange (ETDEWEB)

    Sotic, O; Martinc, R; Kozomara-Maic, S; Cupac, S; Raickovic, N; Radivojevic, J; Badrljica, R; Majstorovic, D; Sanovic, V [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1983-12-15

    After regular shutdown in November 1982, inspection of the fuel elements from the RA reactor core which was done from December 1982 - February 1983 has shown that there are deposits of aluminium oxides on the surface of the fuel cladding. After restart The RA reactor was operated at power levels from 1.8 - 2 MW, with 80% enriched uranium dioxide fuel elements. It was found that there was no corrosion of the fuel element cladding and that it was not possible to find the cause of surface deposition on the cladding surfaces without further operation. It was decided to purify the heavy water permanently during operation and to increase the heavy water flow by operating two pumps. This procedure was adopted in order to decrease the possibility of corrosion. The Safety committee of the Institute has approved this procedure for operating the RA reactor in 1983. The core was made of 80% enriched fuel, critical experiments were done until June 1983, and after that the operation was continued at power levels up to 2 MW. [Serbo-Croat] Pregledom nuklearnog goriva iz tehnoloskih kanala reaktora RA koji je izvrsen u periodu decembear 1982-feburuar 1983. godine nakon zaustavljanja reaktora po isteku novembarske kampanje 1982. godine, ustanovljeno je da ponovo dolazi do stvaranja taloga u obliku hidratisanih oksida aluminiuma na kosuljicama gorivnih elemenata. Nakon ponovnog pustanja u rad, reaktor je do novembra 1981. godine neprekidno bio u pogonu na snagama 1,8 - 2 MW. Jezgro je bilo formirano iskljucivo sa od gorivnih elemenata sa 80% obogacenim uran dioksidom. Utvrdjeno je da kosuljica gorivnog elementa nije korodirala, i da se bez nastval rada ne moze utvrditi uzrok pojave taloga na povrsini kosuljice. Da bi se mogucnost korozije aluminjumskih komponenti u primarnom kolu raktora svela na sto manju meru odluceno je da se vrsi neprekidno preciscavanje teske vode i da se istovremeno poveca protok teske vode radom dve pumpe, Komitet za sigurnost Instituta odobrio je ovakav nacin

  15. CAC-RA1 1958-1998. The first years of the Constituyentes Atomic Center (CAC). History of the first Argentine nuclear reactor (RA-1)

    International Nuclear Information System (INIS)

    Forlerer, Elena; Palacios, Tulio A.

    1998-01-01

    After giving the milestones of the development of the Constituyentes Atomic Center since 1957, the history of the construction of the first nuclear reactor (RA-1) in Argentina, including the local fabrication of its fuel elements, is surveyed. The RA-1 reached criticality on January 17, 1958. The booklet commemorates the 40th year of the reactor operation

  16. Radiation protection at the RA Reactor in 1986, Part -2, Annex 2a, Radioactivity control of the RA reactor environment (atmospheric precipitations, dust, water, soil, plants, fruit...)

    International Nuclear Information System (INIS)

    Ajdacic, N.; Martic, M.; Jovanovic, J.

    1986-01-01

    Control of radioactivity in the biosphere in the vicinity of the RA reactor is part of the radioactivity control done regularly for the whole territory of the Vinca institute (report by the same authors included in this Annex). During 1986 control was conducted according to the plan until May 1, 1986 when a dramatic increase of the precipitations and all other samples from the biosphere was recorded. According to the measured data no significant changes have been found in the surroundings of the RA reactor, until April 29 1986. Since then more detailed control was conducted, the number of samples was increased, apart from standard measuring procedure of total beta activity measurements, gamma spectrometry of all samples was applied. High activity level of the following nuclides was found: Iodine, cerium,cesium, tellurium, ruthenium, barium, lanthanum, etc. As an example activity of ?1?3?1 I in one sample was 564±5 kBq/m 2 [sr

  17. Boron neutron capture therapy (BNCT) translational studies in the hamster cheek pouch model of oral cancer at the new ''B2'' configuration of the RA-6 nuclear reactor

    International Nuclear Information System (INIS)

    Monti Hughes, Andrea; Trivillin, Veronica A.; Schwint, Amanda E.; Longhino, Juan; Boggio, Esteban; Medina, Vanina A.; Martinel Lamas, Diego J.; Garabalino, Marcela A.; Heber, Elisa M.; Pozzi, Emiliano C.C.; Itoiz, Maria E.; Aromando, Romina F.; Nigg, David W.

    2017-01-01

    Boron neutron capture therapy (BNCT) is based on selective accumulation of B-10 carriers in tumor followed by neutron irradiation. We demonstrated, in 2001, the therapeutic effect of BNCT mediated by BPA (boronophenylalanine) in the hamster cheek pouch model of oral cancer, at the RA-6 nuclear reactor. Between 2007 and 2011, the RA-6 was upgraded, leading to an improvement in the performance of the BNCT beam (B2 configuration). Our aim was to evaluate BPA-BNCT radiotoxicity and tumor control in the hamster cheek pouch model of oral cancer at the new ''B2'' configuration. We also evaluated, for the first time in the oral cancer model, the radioprotective effect of histamine against mucositis in precancerous tissue as the dose-limiting tissue. Cancerized pouches were exposed to: BPA-BNCT; BPA-BNCT + histamine; BO: Beam only; BO + histamine; CONTROL: cancerized, no-treatment. BNCT induced severe mucositis, with an incidence that was slightly higher than in ''B1'' experiments (86 vs 67%, respectively). BO induced low/moderate mucositis. Histamine slightly reduced the incidence of severe mucositis induced by BPA-BNCT (75 vs 86%) and prevented mucositis altogether in BO animals. Tumor overall response was significantly higher in BNCT (94-96%) than in control (16%) and BO groups (9-38%), and did not differ significantly from the ''B1'' results (91%). Histamine did not compromise BNCT therapeutic efficacy. BNCT radiotoxicity and therapeutic effect at the B1 and B2 configurations of RA-6 were consistent. Histamine slightly reduced mucositis in precancerous tissue even in this overly aggressive oral cancer model, without compromising tumor control. (orig.)

  18. Boron neutron capture therapy (BNCT) translational studies in the hamster cheek pouch model of oral cancer at the new ''B2'' configuration of the RA-6 nuclear reactor

    Energy Technology Data Exchange (ETDEWEB)

    Monti Hughes, Andrea; Trivillin, Veronica A.; Schwint, Amanda E. [Constituyentes Atomic Center, National Atomic Energy Commission (CNEA), Department of Radiobiology, San Martin, Province Buenos Aires (Argentina); National Research Council (CONICET), Ciudad Autonoma de Buenos Aires (Argentina); Longhino, Juan; Boggio, Esteban [Bariloche Atomic Center, CNEA, Department of Nuclear Engineering, San Carlos de Bariloche, Province Rio Negro (Argentina); Medina, Vanina A.; Martinel Lamas, Diego J. [National Research Council (CONICET), Ciudad Autonoma de Buenos Aires (Argentina); Pontifical Catholic University of Argentina (UCA), Laboratory of Tumoral Biology and Inflammation, School of Medical Sciences, Institute for Biomedical Research (BIOMED CONICET-UCA), Ciudad Autonoma de Buenos Aires (Argentina); Garabalino, Marcela A.; Heber, Elisa M.; Pozzi, Emiliano C.C. [Constituyentes Atomic Center, National Atomic Energy Commission (CNEA), Department of Radiobiology, San Martin, Province Buenos Aires (Argentina); Itoiz, Maria E. [Constituyentes Atomic Center, National Atomic Energy Commission (CNEA), Department of Radiobiology, San Martin, Province Buenos Aires (Argentina); UBA, Department of Oral Pathology, Faculty of Dentistry, Ciudad Autonoma de Buenos Aires (Argentina); Aromando, Romina F. [UBA, Department of Oral Pathology, Faculty of Dentistry, Ciudad Autonoma de Buenos Aires (Argentina); Nigg, David W. [Idaho National Laboratory, Idaho Falls (United States)

    2017-11-15

    Boron neutron capture therapy (BNCT) is based on selective accumulation of B-10 carriers in tumor followed by neutron irradiation. We demonstrated, in 2001, the therapeutic effect of BNCT mediated by BPA (boronophenylalanine) in the hamster cheek pouch model of oral cancer, at the RA-6 nuclear reactor. Between 2007 and 2011, the RA-6 was upgraded, leading to an improvement in the performance of the BNCT beam (B2 configuration). Our aim was to evaluate BPA-BNCT radiotoxicity and tumor control in the hamster cheek pouch model of oral cancer at the new ''B2'' configuration. We also evaluated, for the first time in the oral cancer model, the radioprotective effect of histamine against mucositis in precancerous tissue as the dose-limiting tissue. Cancerized pouches were exposed to: BPA-BNCT; BPA-BNCT + histamine; BO: Beam only; BO + histamine; CONTROL: cancerized, no-treatment. BNCT induced severe mucositis, with an incidence that was slightly higher than in ''B1'' experiments (86 vs 67%, respectively). BO induced low/moderate mucositis. Histamine slightly reduced the incidence of severe mucositis induced by BPA-BNCT (75 vs 86%) and prevented mucositis altogether in BO animals. Tumor overall response was significantly higher in BNCT (94-96%) than in control (16%) and BO groups (9-38%), and did not differ significantly from the ''B1'' results (91%). Histamine did not compromise BNCT therapeutic efficacy. BNCT radiotoxicity and therapeutic effect at the B1 and B2 configurations of RA-6 were consistent. Histamine slightly reduced mucositis in precancerous tissue even in this overly aggressive oral cancer model, without compromising tumor control. (orig.)

  19. Causes of extended shutdown state of 'RA' research reactor in Vinca Institute

    International Nuclear Information System (INIS)

    Pesic, M.; Kolundzija, V.; Ljubenov, V.; Cupac, S.

    2001-01-01

    This paper describes the causes and reasons for extended shutdown state of RA research reactor in the 'Vinca' Institute of Nuclear Sciences. Technical and legal matters that led to decision to stop RA reactor operation in 1984 and further problems related to maintenance and preparation for continuation of operation are given. Influence of nuclear policy of Yugoslav government and the 'Vinca' Institute at prolongation of the reactor shutdown state, as consequence of changing of nuclear programme in the country and the world are discussed and underlined. An overview of the legislation in the field of nuclear safety and regulatory control of radiation sources and radioactive materials in Yugoslavia is presented. (author)

  20. RA reactor Action plan for 1978 - Annex VI; Prilog VI - Plan rada reaktora RA za 1978. godinu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1977-12-15

    This annex include a detailed monthly action plan of the RA reactor for 1978. It was planned that the reactor will operate at nominal and lower power levels for 158 days. The plan is made with the aim to achieve same annual neutron flux as in 1977, which is somewhat higher then the annual production in the period from 1968-1975. [Serbo-Croat] Ovaj prilog sadrzi detaljan plan rada reaktora RA za 1978. godinu. Planirano je da reaktor radi na nominalnoj snazi of 6,5 MW i na manjim snagama ukupno 158 dana. Plan je napravljen tako da se ostvari godisnja proizvodnja neutronskog fluksa u obimu koji je relaizovan 1977. godine sto je nesto vise od godisnje proizvodnje u periodu 1968-1975.

  1. RA Research reactor, Part 1, Operation and maintenance of the RA nuclear reactor for 1988; Istrazivacki nuklearni reaktor RA, deo 1, pogon i odrzavanje nukleanog reaktora RA u 1988. godini

    Energy Technology Data Exchange (ETDEWEB)

    Sotic, O; Martinc, R; Cupac, S; Sulem, B; Badrljica, R; Majstorovic, D; Sanovic, V [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1988-12-15

    According to the action plan for 1988, operation of the RA reactor should have been restarted in October, but the operating license was not obtained. Control and maintenance of the reactor components was done regularly and efficiently dependent on the availability of the spare parts. The major difficulty was maintenance of the reactor instrumentation. Period of the reactor shutdown was used for repair of the heavy water pumps in the primary coolant loop. With the aim to ensure future safe and reliable reactor operation, action were started concerning renewal of the reactor instrumentation. Design project was done by the soviet company Atomenergoeksport. The contract for constructing this equipment was signed, and it is planned that the equipment will be delivered by the end of 1990. In order to increase the space for storage of the irradiated fuel elements and its more efficient usage, projects were started concerned with reconstruction of the existing fuel handling equipment, increase of the storage space and purification of the water in the fuel storage pools. These projects are scheduled to be finished in mid 1989. This report includes 8 annexes concerning reactor operation, activities of services and financial issues. [Serbo-Croat] Prema planu za 1988. godinu, reaktor RA je trebalo da pusten u rad oktobra meseca, medjutim nije dobio dozvolu za nastavak rada. Kontrola i odrzavanje opreme izvrsavani su redovno i efikasno, u granicama koje su diktirane raspolozivoscu repromaterijala i rezervnih delova. Najvecu poteskocu pricinjavalo je odrzavanje instrumentacije. Period stajanja u 1988. godini iskoriscen je za remont teskovodnih pumpi u primarnom kolu hladjenja. U cilju povecanja pouzdanosti rada reaktora zapoceti su radovi na modernizaciji instrumentacije, projekat je izradjen u sovjetskoj organizaciji Atomenergoeksport, sklopljen je ugovor o izradi ove opreme koja bi trebalo da bude isporucena do kraja 1990. U cilju povecanja prostora za skladistenje ozracenog

  2. Simple computational modeling for human extracorporeal irradiation using the BNCT facility of the RA-3 Reactor

    International Nuclear Information System (INIS)

    Farias, Ruben; Gonzalez, S.J.; Bellino, A.; Sztenjberg, M.; Pinto, J.; Thorp, Silvia I.; Gadan, M.; Pozzi, Emiliano; Schwint, Amanda E.; Heber, Elisa M.; Trivillin, V.A.; Zarza, Leandro G.; Estryk, Guillermo; Miller, M.; Bortolussi, S.; Soto, M.S.; Nigg, D.W.

    2009-01-01

    We present a simple computational model of the reactor RA-3 developed using Monte Carlo transport code MCNP. The model parameters are adjusted in order to reproduce experimental measured points in air and the source validation is performed in an acrylic phantom. Performance analysis is carried out using computational models of animal extracorporeal irradiation in liver and lung. Analysis is also performed inside a neutron shielded receptacle use for the irradiation of rats with a model of hepatic metastases.The computational model reproduces the experimental behavior in all the analyzed cases with a maximum difference of 10 percent. (author)

  3. RA reactor operation and maintenance in 1994, Part 1; Deo 1 - Pogon i odrzavanje nuklearnog reaktora RA u 1994. godini

    Energy Technology Data Exchange (ETDEWEB)

    Sotic, O; Cupac, S; Sulem, B; Zivotic, Z; Mikic, N; Tanaskovic, M [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1994-12-01

    During the previous period RA reactor was not operated because the Committee of Serbian ministry for health and social care has cancelled the operation licence in August 1984. The reason was the non existing emergency cooling system and lack of appropriate filters in the special ventilation system. The planned major tasks were fulfilled: building of the new emergency cooling system, reconstruction of the existing ventilation system, and renewal of the reactor power supply system. The existing RA reactor instrumentation was dismantled, only the part needed for basic measurements when reactor is not operated, was maintained. Renewal of the reactor instrumentation was started but but it is behind the schedule because the delivery of components from USSR was stopped for political reasons. The spent fuel elements used from the very beginning of reactor operation are stored in the existing pools. Project concerned with increase of the storage space and the efficiency of handling the spent fuel elements has started in 1988 and was fulfilled in 1990. Control and maintenance of the reactor instrumentation and tools was done regularly but dependent on the availability of the spare parts. Training of the existing personnel and was done regularly, but the new staff has no practical training since the reactor is not operated. Lack of financial support influenced strongly the status of RA reactor. [Serbo-Croat] U proteklom periodu reaktor RA nije bio u pogonu zato sto je 30. jula Republicki komitet za zdravlje i socijalnu politiku republike Srbije, zabranio njegov rad zbog toga sto reaktor ne poseduje sistem za udesno hladjenje i ne poseduje odgovarajuce filtere u sistemu specijalne ventilacije. Zavrseni su radovi na izgradnji sistema za udesno hladjenje, rekonstrukciji postojeceg sistema specijalne ventilacije i rekonstrukciji sistema za napajanje elektricnom energijom. Zapoceti su radovi na modernizaciji, odnosno zameni instrumentacije reaktora ali njegova realizacija kasni

  4. RA Research nuclear reactor, Part I - RA nuclear reactor operation, maintenance and utilization in 1984; Istrazivacki nuklearni reaktor RA - Deo I - Pogon, odrzavanje i eksploatacija nuklearnog reaktora RA u 1984. godini

    Energy Technology Data Exchange (ETDEWEB)

    Sotic, O; Martinc, R; Cupac, S; Sulem, B; Badrljica, R; Majstorovic, D; Sanovic, V [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

    1984-12-15

    During the 1984 the reactor operation was limited by the temporary operating license issued by the Committee of Serbian ministry for health and social care. The reason was the non existing emergency cooling system and lack of appropriate filters in the special ventilation system. This temporary license has limited the reactor power to 2 MW from 1981. Operation of the primary cooling system was changed in order to avoid appearance of the previously noticed aluminium oxyhydrate on the surface of the fuel element claddings. The new cooling regime enabled more efficient heavy water purification. Control and maintenance of the reactor instrumentation and tools was done regularly but dependent on the availability of the spare parts. In order to enable future reliable operation of the RA reactor, according to new licensing regulations, during 1984, three major tasks are planned: building of the new emergency system, reconstruction of the existing ventilation system, and renewal of the reactor instrumentation. Financing of the planned activities will be partly covered by the IAEA. this Part I of the report includes 8 Annexes describing in detail the reactor operation, and 6 special papers dealing with the problems of reactor operation and utilization.

  5. Measurement of neutrons in the RA reactor cell; Merenje neutrona u elementarnoj celiji reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

    Raisic, N; Bosevski, T [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1961-12-15

    A special experimental device was constructed for measuring the neutron flux distribution in the RA reactor cell. This device simulated the reactor cell in order to avoid disturbance in the reactor core. It was made of an aluminium cylindrical vessel having outer diameter same as the vertical experimental channel and contained three fuel slugs. Hole was made in through the center of the fuel slugs and a copper wire was placed in the hole for measuring the thermal neutron flux distribution. It was placed in the experimental channel VK-5 in the location of highest neutron flux. Handling of samples for irradiation was quite simple.

  6. The effect of boron dilution transient on the VVER-1000 reactor core using MCNP and COBRA-EN codes

    Energy Technology Data Exchange (ETDEWEB)

    Jafari, Naser; Talebi, Saeed [Amirkabir Univ. of Technology, Tehran Polytechnic (Iran, Islamic Republic of). Dept. of Energy Engineering and Physics

    2017-07-15

    In this paper, the effect of boron dilution transient, as a consequence of the malfunction of the boron control system, was investigated in a VVER-1000 reactor, and then an appropriate setpoint was determined for the actuation of the emergency protection system to the reactor shutdown. In order to simulate the boron dilution, first, the whole reactor core was simulated by MCNPX code to compute the radial and axial power distribution. Then, the COBRA-EN code was employed using calculated power distribution for analyzing the thermal-hydraulic of hot fuel assembly and for extracting the safety parameters. For the safe operation of the reactor, certain parameters must be in defined specified ranges. Comparison between our results and FSARs data shows that the present modeling provides a good prediction of boron dilution transient with the maximum relative difference about 4%.

  7. Dry storage of MTR spent fuel from the Argentine radioisotope production reactor RA-3

    International Nuclear Information System (INIS)

    Di Marco, A.; Gillaume, E.J.; Ruggirello, G.; Zaweruchi, A.

    1996-01-01

    The nuclear fuel elements of the RA-3 reactor consist in 19 rectangular fuel plates held in position by two lateral structural plates. The whole assembly is coupled to the lower nozzles that fits in the reactor core grid. The inner plates are 1.5 mm thick, 70.5 mm wide and 655 mm long and the outer plates are 100 mm longer. The fuel plates are formed by a core of an AI-U alloy co-laminated between two plates of Al. Enrichment is 90% 235 U. After being extracted from the reactor, the fuel elements have been let to cool down in the reactor storage pool and finally moved to the storage facility. This facility is a grid of vertical underground channels connected by a piping system. The system is filled with processed and controlled water. At the present the storage capacity of the facility is near to be depleted and some indications of deterioration of the fuel elements has been detected. Due to the present status of the facility and the spent fuel stored there, a decision has been taken to proceed to modify the present underwater storage to dry storage. The project consist in: a) Decontamination and conditioning of the storage channels to prepare them for dry storage. b) Disassembly of the fuel elements in hot cells in order to can only the active fuel plates in an adequate tight canister. c) The remnant structural pieces will be treated as low level waste. (author). 10 figs

  8. The epithermal neutron-flux distribution in the reactor RA - Vinca

    International Nuclear Information System (INIS)

    Marinkov, V.; Bikit, I.; Martinc, R.; Veskovic, M.; Slivka, J.; Vaderna, S.

    1987-01-01

    The distribution of the epithermal neutron flux in the reactor RA - Vinca has been measured by means of Zr - activation detectors. In the channel VK-8 non-homogeneous flux distribution was observed (author) [sr

  9. RA Research reactor Annual report 1981 - Part 1, Operation, maintenance and utilization of the RA reactor

    International Nuclear Information System (INIS)

    Sotic, O.; Milosevic, M.; Martinc, R.; Kozomara-Maic, S.; Cupac, S.; Radivojevic, J.; Stamenkovic, D.; Skoric, M.

    1981-12-01

    The RA nuclear reactor stopped operation after March 1979 campaign due to appearance of aluminium oxyhydrates deposits on the surface of fuel element claddings. Relevant decisions of the Sanitary inspection body of the Ministry of health and the Director General of the 'Boris Kidric' Institute of nuclear sciences, Vinca, banned further reactor operation until reasons caused aluminium oxyhydrates deposition are investigated and removed to enable regular reactor operation. Until the end of 1979 and during 1980, after a series of analyses and findings that caused cease of reactor operation, all the preparatory actions needed for restart were performed. Due to the fact that there is no emergency cooling system and no appropriate filtering system at the reactor, and according to the new regulations about start up of nuclear facilities, the Sanitary inspection body made a decision about temporary licence for reactor start-up meaning performance of the 'zero experiment' limiting the operating power to 1% of the nominal power. Accordingly the reactor was restarted on January 21 1981. Criticality was reached with the core made of 80% enriched fuel elements only. After the experiment was finished by the end of March a permission was demanded for operation at higher power levels at full power. Taking into account the state of the reactor components the operating licence was issued limiting the power to 2 MW until reconstruction of the ventilation system and construction of the emergency cooling system are fulfilled. Program of testing operation started on September 15 1981 increasing gradually the operating power. Thus the reactor was operated at 2 MW power for 15 days during November and December. The total production achieved in 1981 was 1698 MWh. This enabled isotopes production at the reactor during last two months. Control and maintenance of the reactor components and systems was done regularly and efficiently within limits imposed by availability of spare parts. The

  10. Nuclear Reactor RA Safety Report, Vol. 15, Analysis of significant accidents; Izvestaj o sigurnosti nuklearnog reaktora RA, Knjiga 15, Analiza znacajnih akcidenata

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1986-11-01

    Power excursions of the RA reactor a mathematical model of reactor kinetic behaviour was formulated to describe power and temperature coefficients for both reactor fuel and moderator. Computer code TM-1 was written for analysis of possible reactor accidents. Power excursions caused by uncontrolled control rod removal and heavy water flow into the central vertical experimental channel were analyzed. Accidents caused by fuel elements handling were discussed including possible fuel element damage. Although the probability for uncontrolled radioactive materials release into the environment is very low, this type of accidents are analyzed as well including the impact on the personnel and the environment. A separate chapter describes analysis of the loss of flow accident. Safety analysis covers the possible damage of the outer steel Ra reactor vessel and the water screens which are part of the water biological shield. [Serbo-Croat] Radi analize dinamickog ponasanja reaktora RA u toku ekskurzije snage formulisan je matematicki model koji opisuje promene snage i temperature goriva i moderatora. Za analizu predpostavljenih akcidenata realizovan je racunarski program TM-1. Analizirane su ekskurzije snage usled nekontrolisanog izvlacenja kontrolnih sipki i punjenja centralnog vertikalnog eksperimentalnog kanala teskom vodom. Analizirani su akcidenti pri rukovanju nuklearnim gorivom ukljucujuci ostecenje nuklearnog goriva. Iako je verovatnoca za nekontrolisano rasturanje radioaktivnog materijala mala, analizirani su i ovakvi moguci akcidenti koji mogu uticati kako na osoblje reaktora tako i na okolinu. Posebno poglavlje obuhvata analizu akcidenta u slucaju prestanka cirkulacije primarnog hladioca. Analiza sigurnosti reaktora obuhvata i moguce ostecenje spoljasnjeg celicnog suda reaktora RA kao i vodenih ekrana koji su deo vodenog bioloskog stita.

  11. RA Reactor operation and maintenance (I-IX), part VIII, Task 3.08/05, Decontamination of the reactor

    International Nuclear Information System (INIS)

    Zecevic, V.

    1963-12-01

    Permanent increase of radiation in the heavy water system was noticed during first three year of the RA reactor operation, even when the reactor was shutdown. It was found that there was no failure of the fuel element cladding. Radioactive cobalt was found in the heavy water which was rather strange. During repair of the heavy water system, it has been found that stellite was used for coating the heavy water pumps. Since stellite is a cobalt alloy, this could have been the source of radioactive cobalt in the heavy water. The stellite coating was damaged due to friction and particle of cobalt appeared in the coolant, they were activated since they were in the core. decontamination of the heavy water and the heavy water coolant loop was a must . Beside the detailed report on the contamination and decontamination of the heavy water system this volume includes 14 annexes describing the investigation of the event and the whole procedure of decontamination

  12. RA Research reactor Annual report 1981 - Part 1, Operation, maintenance and utilization of the RA reactor; Istrazivacki nuklearni reaktor RA, Deo 1 - Pogon, odrzavanje i eksploatacija reaktora u 1981. godini

    Energy Technology Data Exchange (ETDEWEB)

    Sotic, O; Milosevic, M; Martinc, R; Kozomara-Maic, S; Cupac, S; Radivojevic, J; Stamenkovic, D; Skoric, M [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1981-12-15

    The RA nuclear reactor stopped operation after March 1979 campaign due to appearance of aluminium oxyhydrates deposits on the surface of fuel element claddings. Relevant decisions of the Sanitary inspection body of the Ministry of health and the Director General of the 'Boris Kidric' Institute of nuclear sciences, Vinca, banned further reactor operation until reasons caused aluminium oxyhydrates deposition are investigated and removed to enable regular reactor operation. Until the end of 1979 and during 1980, after a series of analyses and findings that caused cease of reactor operation, all the preparatory actions needed for restart were performed. Due to the fact that there is no emergency cooling system and no appropriate filtering system at the reactor, and according to the new regulations about start up of nuclear facilities, the Sanitary inspection body made a decision about temporary licence for reactor start-up meaning performance of the 'zero experiment' limiting the operating power to 1% of the nominal power. Accordingly the reactor was restarted on January 21 1981. Criticality was reached with the core made of 80% enriched fuel elements only. After the experiment was finished by the end of March a permission was demanded for operation at higher power levels at full power. Taking into account the state of the reactor components the operating licence was issued limiting the power to 2 MW until reconstruction of the ventilation system and construction of the emergency cooling system are fulfilled. Program of testing operation started on September 15 1981 increasing gradually the operating power. Thus the reactor was operated at 2 MW power for 15 days during November and December. The total production achieved in 1981 was 1698 MWh. This enabled isotopes production at the reactor during last two months. Control and maintenance of the reactor components and systems was done regularly and efficiently within limits imposed by availability of spare parts. The

  13. Radiation dosimetry of the reactor RA at Vinca, Measurements by isothermal calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Radak, B; Markovic, V; Draganic, I [Institute of Nuclear Sciences Boris Kidric, Department of radiation chemistry, Vinca, Beograd (Serbia and Montenegro)

    1961-10-15

    In this work we have made attempts to: analyze the problems of reactor radiation dosimetry; describe the solution of this problem by the calorimetric method; present our results of measurements on the reactor RA at Vinca, and to describe the method, apparatus and measuring equipment used. Use was made of the isothermal calorimeter with thermistors which measured the absorbed dose rates within the range 10{sup 4}-10{sup 6} rad/h, with an accuracy of 2-5%. It was shown that the reactor radiation in which the thermal neutron flux is up to the order of magnitude 10{sup 12} n/cm{sup 2}/sec, and the integral thermal neutron flux up to about 10{sup 16} n/cm{sup 2} exerts no significant influence upon the working characteristics of the thermistors used. Determination was made of the absorbed dose distribution into the gamma-ray and the neutron contribution. For this purpose we used 3 materials: ordinary water, heavy water and graphite. Measurements were carried out in two vertical experimental holes 'VK-5' and 'VK-9' of the reactor RA at several heights. It has been shown that the absorbed dose height distribution agrees well with the thermal flux distribution curve, although the relations of the absorbed doses of the two holes are not in accordance with the corresponding thermal flux relations (author)

  14. Radiation dosimetry of the reactor RA at Vinca, Measurements by isothermal calorimeter

    International Nuclear Information System (INIS)

    Radak, B.; Markovic, V.; Draganic, I.

    1961-01-01

    In this work we have made attempts to: analyze the problems of reactor radiation dosimetry; describe the solution of this problem by the calorimetric method; present our results of measurements on the reactor RA at Vinca, and to describe the method, apparatus and measuring equipment used. Use was made of the isothermal calorimeter with thermistors which measured the absorbed dose rates within the range 10 4 -10 6 rad/h, with an accuracy of 2-5%. It was shown that the reactor radiation in which the thermal neutron flux is up to the order of magnitude 10 12 n/cm 2 /sec, and the integral thermal neutron flux up to about 10 16 n/cm 2 exerts no significant influence upon the working characteristics of the thermistors used. Determination was made of the absorbed dose distribution into the gamma-ray and the neutron contribution. For this purpose we used 3 materials: ordinary water, heavy water and graphite. Measurements were carried out in two vertical experimental holes 'VK-5' and 'VK-9' of the reactor RA at several heights. It has been shown that the absorbed dose height distribution agrees well with the thermal flux distribution curve, although the relations of the absorbed doses of the two holes are not in accordance with the corresponding thermal flux relations (author)

  15. RA Research reactor, Annual report 1969

    International Nuclear Information System (INIS)

    Milosevic, D. et al.

    1969-12-01

    During 1969, the RA Reactor was operated at nominal power of 6.5 MW for 200 days, and 15 days at lower power levels. Total production mounted to 31131 MWh which is 3.77% higher than planned. Reactor was used for irradiation and experiments according to the demand of 463 users from the Institute and 63 external users. This report contains detailed data about reactor power and experiments performed in 1969. It is concluded that the reactor operated successfully according to the plan. If there had been no problems with power supply during last three months and Danube low water level in September and October the past year would have been the most successful up to now. The number od scram shutdowns was not higher than during past two years in spite of the difficulties in the last quarter. There were three incidents which caused higher personnel exposure during operation. One, was the destruction of the canner with silver (because the time spent in the core was too long) which caused the surface contamination of the platform, the background radiation was 10 to 100 times higher than regular. The other two cases were caused by failure of the device for handling the fuel slugs in the fuel channels during refuelling. Reactor refuelling was done four times during 1969, and 499 fresh fuel slugs were used. Refuelling applied the approach of 'mixing' the fresh fuel slugs with the 'old' fuel slugs in the fuel channel. Decontamination of surfaces was on the same level as previously in spite of the problems with silver. Since two staff members have left, the present number od employees is now the minimum needed for reactor operation and maintenance. It is stated that the operation of components and equipment is on sufficiently high level after ten years of reactor operation. The action plan for 1970 is made according to the same principles as in previous four years but the planned production is decreased to 25000 MWh, because control of important components is needed after ten

  16. Operation and maintenance of the RA reactor, RA Research reactor. Annual report 1976

    International Nuclear Information System (INIS)

    Martinc, R.

    1976-12-01

    During 1976 the Ra reactor was operating for about 30% shorter period than usual. The reason were extraordinary repair activities within regular and investment maintenance as well as repair of failures caused by neglected maintenance during previous 6 years. Delay was caused by unavailability of fuel (2% enriched fuel elements are spent) and the new 80% enriched fuel demanded experimental and theoretical analyses before being introduced into the core. Safety analyses concerned with using 80% enriched fuel both experimental and theoretical were successfully fulfilled. The December 1976 successful experimental campaign can be marked as end of the 17 years period of using 2% enriched fuel and start of the new period of using highly enriched fuel. This is significant not only for the reactor itself but for the users, because it would result in increase of neutron flux by 50% with the increase of costs by only 4%. Demand was submitted for obtaining the final license for transition operating regime with highly enriched fuel which would save at least 2 200 000 dinars. This will enable reactor operation in 1977 and later on, without interruption by 'critical' and other experiments related to new highly enriched fuel. A high number of repair and other urgent activities were fulfilled in order to enable safe operation. Some of these activities were done never before and some were neglected during past 6 years. The most important tasks were: purchase of Al tubes made of special alloy, fabrication and mounting of the fuel channel; overall investigation of reactor vessel leakage; repair of the heavy water pump; exchange of two vertical channels. basic equipment for construction of emergency cooling system was purchased. Hot cells are equipped for independent utilisation [sr

  17. Temperature reactivity coefficient of the RA reactor; Temperaturni koeficijenat reaktivnosti reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

    Raisic, N; Strugar, P; Dobrosavljevic, N [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1961-12-15

    Temperature reactivity coefficient of the RA reactor was determined as follows. Stabilization of moderator temperature and graphite reflector was achieved in the reactor operated at power levels of 20, 100, 500, 1000, 3000 and 5000 kW. Temperature change of the moderator was achieved by changing the water flow rate in the secondary cooling system. The fuel temperature was changed simultaneously. During the measurement at each power level the temperature change was between 30 - 50 deg C. Changing the position of the automated regulator is registered during moderator temperature change, and these changes were used for determining the total reactivity change by using the calibration curves for the automated regulator. In the measured temperature range the the reactivity change was linear and it was possible to determine the total temperature coefficient.

  18. Calculation-measurement comparison for control rods reactivity in RA-3 nuclear reactor

    International Nuclear Information System (INIS)

    Estryk, Guillermo; Gomez, Angel

    2002-01-01

    The RA-3 Nuclear Reactor of the Atomic Energy National Commission from Argentina, begun working with high enrichment fuel elements in 1967, and turned to low enrichment by 1990. During 1999 it was found out that several fuel elements had problems, so more than 50 % of them had to be removed from the core. Because of this, it was planned to go from core 93 to core 94 with special care from nuclear safety point of view. Core 94 was preceded by other five, T-1 to T-5, only as transitory ones. The care implied several nuclear parameters measurements: core reactivity excess, calibration of control rods, etc. Calculations were performed afterwards to simulate those measurements using the neutron diffusion code PUMA. The comparison shows a good agreement for more than 80% of the cases with differences lower than 10% in reactivity. The greatest differences were found in the last part of the control rods calibration and a better calculation of cell constants is planned to be done in order to improve the adjustment. (author)

  19. Up-dating of the RA-0 reactor shielding. Gamma and neutron isodoses

    International Nuclear Information System (INIS)

    Murua, Carlos A.; Chautemps, Norma A.; Ackerley, Alejandro F.; Alexeiew, Vladimiro

    1999-01-01

    A comparative analysis of the historical shielding configurations of the RA-0 reactor is performed and the comparison methodology is described. The gamma and neutron dose mapping of the last two stages of the reactor shielding has been carried out and the results are analysed

  20. RA Research reactor, Annual report 1971; Istrazivacki nuklearni reaktor RA - Izvestaj za 1971. godinu - Pogon i odrzavanje

    Energy Technology Data Exchange (ETDEWEB)

    Milosevic, D et al. [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1971-12-15

    During 1971, the RA Reactor was operated at nominal power of 6.5 MW for 190 days, and 50 days at lower power levels. Total production mounted to 31606 MWh which is 5.3% higher than planned, and the highest annual level since the reactor started operation. Reactor was used for irradiation and experiments according to the demand of 425 users, of which 370 from the Institute and 55 external users. This report contains detailed data about reactor power and experiments performed in 1971. Discrepancies from the action plan, meaning higher production was achieved in June and December due to special demand of the users. Total number of interruptions was lower than during all the previous years, and were caused mainly due to power cuts during reactor operation. There was no longer interruption caused by failures of the equipment. There was only on scram shutdown during this year caused by a false signal of the reactor control instrumentation. Shorter interruptions resulted from breaking of connectors in the technical water pipe system caused by soil sliding near the pumping station on the Danube. Total personnel exposure dose was lower than during previous years. There was no accident nor any event that could be called accidental. Decontamination od surfaces was less than during previous years. It was concluded that the successful operation in 1971 resulted from efficient work during past years. But, some of the activities were interrupted due to undefined policy concerned with operation of the RA reactor and financial issues. This involves study of the possibility to use highly enriched fuel that would increase the useful neutron flux and the reactor compatibility with similar reactors for the future ten years. Another project that has been interrupted is construction of the emergency core cooling system which is important for the reactor safety. Financial problems have influenced not only the reactor operation but the number of employees, which could cause negative

  1. Isolation and characterization of bacteria from wasted ionic exchange resins kept at Area de Gestion Ezeiza belonging to RA-3 Reactor

    International Nuclear Information System (INIS)

    Mosquera Rodriguez, Leon; Pizarro, Ramon A.

    2009-01-01

    A spent ionic exchange resin kept at Area de Gannet's Ezeiza (Age), belonging to RA-3 Reactor, was treated with sterile water. Microorganisms suspended in the aqueous sample were isolated by several methods, broadening as much as possible cell recovery conditions. Bacteria were subject to purity controls and re-isolation when necessary. Characterization of the strains found in the sample included morphological, physiological and biochemical tests as well as stains. Being the spent resins volume reduction at Age the main purpose, a screening experiment is proposed based on bacteria capability to take carbon from the sediment present in the liquid sample. Recovered bacteria are at least the following: Method I: Bacillus cereus, Bacillus circulans, Bacillus sp., Pseudomonas pseudoalcaligenes, Pseudomonas acidovorans, Pseudomonas sp. Method II: Bacillus cereus, Pseudomonas alcaligenes, Flavimonas sp., Agrobacterium sp. Method III: Bacillus circulans, Bacillus sphaericus, Kocuria rosea, Kytococcus sedentarius, Pseudomonas acidovorans. Microorganisms present in the sample are characteristic of those having low microbiological-contamination levels. Way III is an isolation method whose design would lead to find bacteria having the desired properties in order to diminish the volume of RA-3 Reactor spent resins. (author)

  2. Boron biodistribution study in colorectal liver metastases patients in Argentina

    International Nuclear Information System (INIS)

    Cardoso, J.; Nievas, S.; Pereira, M.; Schwint, A.; Trivillin, V.; Pozzi, E.; Heber, E.; Monti Hughes, A.; Sanchez, P.; Bumaschny, E.; Itoiz, M.; Liberman, S.

    2009-01-01

    Ex-situ BNCT for multifocal unresectable liver metastases employing whole or partial autograft techniques requires knowledge of boron concentrations in healthy liver and metastases following perfusion and immersion in Wisconsin solution (W), the procedure employed for organ preservation during ex-situ irradiation. Measurements of boron concentration in blood, liver and metastases following an intravenous infusion of BPA-F in five colorectal liver metastases patients scheduled for surgery were performed. Tissue samples were evaluated for boron content pre and post perfusion and immersion in W. Complementary histological studies were performed. The data showed a dose-dependent BPA uptake in liver, a boron concentration ratio liver/blood close to 1 and a wide spread in the metastases/liver concentration ratios in the range 0.8-3.6, partially attributable to histological variations between samples. Based on the boron concentrations and dose considerations (liver≤ 15 Gy-Eq and tumor≥40 Gy-Eq) at the RA-3 thermal neutron facility (mean flux of about (6±1)x10 9 n cm -2 s -1 ), ex-situ treatment of liver metastases at RA-3 would be feasible.

  3. Biodistribution of Boron compounds in an experimental model of liver metastases for Boron Neutron Capture (BNCT) Studies

    International Nuclear Information System (INIS)

    Garabalino, Marcela A.; Monti Hughes, Andrea; Molinari, Ana J.; Heber, Elisa M.; Pozzi, Emiliano C.C.; Itoiz, Maria E.; Trivillin, Veronica A.; Schwint, Amanda E.; Nievas, Susana; Aromando, Romina F.

    2009-01-01

    Boron Neutron Capture Therapy (BNCT) is a binary treatment modality that involves the selective accumulation of 10 B carriers in tumors followed by irradiation with thermal or epithermal neutrons. The high linear energy transfer alpha particles and recoiling 7 Li nuclei emitted during the capture of a thermal neutron by a 10 B nucleus have a short range and a high biological effectiveness. Thus, BNCT would potentially target neoplastic tissue selectively. In previous studies we demonstrated the therapeutic efficacy of different BNCT protocols in an experimental model of oral cancer. More recently we performed experimental studies in normal rat liver that evidenced the feasibility of treating liver metastases employing a novel BNCT protocol proposed by JEC based on ex-situ treatment and partial liver auto-transplant. The aim of the present study was to perform biodistribution studies with different boron compounds and different administration protocols to determine the protocols that would be therapeutically useful in 'in vivo' BNCT studies at the RA-3 Nuclear Reactor in an experimental model of liver metastases in rats. Materials and Methods. A total of 70 BDIX rats (Charles River Lab., MA, USA) were inoculated in the liver with syngeneic colon cancer cells DH/DK12/TRb (ECACC, UK) to induce the development of subcapsular metastatic nodules. 15 days post-inoculation the animals were used for biodistribution studies. A total of 11 protocols were evaluated employing the boron compounds boronophenylalanine (BPA) and GB-10 (Na 2 10 B 1 -0H 10 ), alone or combined employing different doses and administration routes. Tumor, normal tissue and blood samples were processed for boron measurement by ICP-OES. Results. Several protocols proved potentially useful for BNCT studies in terms of absolute boron concentration in tumor and preferential uptake of boron by tumor tissue, i.e. BPA 15.5 mg 10 B/kg iv + GB-10 50 mg 10 B/kg iv; BPA 46.5 mg 10 B/kg ip; BPA 46.5 mg 10 B/kg ip

  4. Operation, maintenance and utilization of the RA reactor, Annual report 1978; Pogon, odrzavanje i eksploatacija reaktora RA, Izvestaj o radu u 1978. godini

    Energy Technology Data Exchange (ETDEWEB)

    Milosevic, M [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1978-12-15

    It has been planned for 1978 that the RA reactor would be operated for 158 dana at nominal power of 6.5 MW meaning production of 24 648 MWh. The plan was fulfilled since 24 652 MWh was produces. Reactor operation for 158 days is relevant to reactor operation for 200 days in the period before 1975. The reason is increased neutron flux achieved due to improved fuel management and the characteristics of the new 80% enriched fuel. At the end of 1978 the reactor core contained 45% of 80% enriched fuel elements. Increase of neutron flux has shortened the typical time needed for irradiation of the most important samples for isotope production. This significant success in reactor operation is at the same time an obligation for increasing its utilization. Some new trends proposed for increasing reactor utilization capacities were presented at the Conference on utilization of research nuclear reactors in Yugoslavia held in May 1978. [Serbo-Croat] Reaktor RA imao je u planu za 1978. godinu 158 dana rada na nominalnoj snazi od 6.5 MW, sto odgovara radu od 24 648 MWh. Ostvareno je 24 652 MWh sto znaci da je plan ostvaren. Rad reaktora od 158 dana odgovara radu reaktora od 200 dana u periodu pre 1975. godine. Razlog je povecanje neutronskog fluksa zahvaljujuci usavrsenom rukovanju gorivom i karakteristikama novog 80% obogacenog goriva. Krajem 1978. godine 45% jezgra reaktora bilo je popunjeno novim 80% obogacenim gorivom. Povecani neutronski fluks omogucio je skracenje vremena ozracivanja vaznih uzoraka za proizvodnju radioaktivnih izotopa. Ovaj znacajan uspeh je istovremeno obaveza znatno veceg iskoriscenja reaktora RA. Rezultati napora da se postigne vece iskoriscenje reaktora RA prezentirani su na Konferenciji o koriscenju nuklearnih reaktora u Jugoslaviji koja je odrzana u maju 1978.

  5. Application of the neutron noise technique for measurement of reactivity for subcritical reactor RA-4

    International Nuclear Information System (INIS)

    Orso, J; Marenzana, A

    2012-01-01

    Reactor core RA-4 is divided into two parts that come together to start reactor. The reactor with core separate has the largest subcritical condition, this condition is more secure and therefore the reactor shutdown. In this paper measurements are made of the decay constant of the neutron prompt ' P ', using the α-Rossi and α-Feynman methods to calculate the reactivity of the reactor core for different positions. Both techniques are compared and reactivity is obtained for several position of the reactor core using the α-Rossi technical which is obtained a function that gives the reactivity depending on the separation of the core length. Both techniques are verified using a no multiplicative system. Reactivity values for different position of the core obtained by α-Rossi technique are: $[0 cm] = (-11+/-1) dollar, $[3 cm] = (-7+/-1) dollar, $[3.5 cm] (-5.5+/-0.8) dollar, $[4.2 cm] = (-3.8+/-0.3) dollar y $[4.5] = (-3.0+/-0.1) dollar (author)

  6. Measurement of transient hydrodynamic characteristics of the reactor RA primary cooling system

    International Nuclear Information System (INIS)

    Jovic, L.; Majstorovic, D.; Zeljkovic, I.

    1987-01-01

    Experimental study of transient hydrodynamic characteristics of the research nuclear reactor RA by simultaneous measurements of fluid flow and pressure on several locations of the RA primary coolant system is done. Loss of electric power transient on the main circulation pumps is simulated. measurement methodology, data processing and results of measured data analysis are given. (author)

  7. A preclinical study of boron neutron capture therapy (BNCT) of spontaneous tumors in cats at RA-6 in Argentina

    International Nuclear Information System (INIS)

    Trivillin, Veronica A.; Heber, Elisa M.; Itoiz, Maria E.; Schwint, Amanda E.; Calzetta, Osvaldo A.; Blaumann, Hernan R.; Longhino, J.; Rao, Monica; Cantarelli, Maria de los A.

    2005-01-01

    BNCT is a binary treatment modality that combines irradiation with a thermal or epithermal neutron beam with tumor-seeking, boron containing drugs to produce selective irradiation of tumor tissue. Having demonstrated that BNCT mediated by boronophenylalanine (BPA) induced control of experimental squamous cell carcinomas (SCC) of the hamster cheek pouch mucosa with no damage to normal tissue we explored the feasibility and safety of treating spontaneous head and neck tumors, with particular focus on SCC, of terminal feline patients with low dose BPA-BNCT employing the thermal beam of RA-1. Having demonstrated partial tumor control with no radio toxic effects, the aim of the present study was to evaluate the effect of BPA-BNCT on tumor and normal tissue in 3 cases of spontaneous SCC in feline patients employing a higher neutron fluence than in the previous study. The present study was performed at RA-6 with the thermalized epithermal neutron beam. All three irradiations were successful. Except for an initial, moderate and reversible mucositis, no significant radio toxic effects were observed in terms of clinical follow-up, histological examination, biochemical analysis and assessment of autopsy material. Partial tumor control was evidenced in terms of growth inhibition and partial necrosis and improvement in the quality of life during the survival period. Optimization of the therapeutic efficacy of BNCT would require improvement in boron tumor targeting and strategies to increase in-depth dose in large tumors. (author)

  8. Annex 1 - Task 08/12 final report, testing the RA reactor fuel element; Prilog 1 - Zavrsni izvestaj o podzadatku 08/12, Ispitivanje gorivnog elementa reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

    Mihajlovic, A [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1961-12-15

    Testing of the RA reactor fuel element is presented in Annex 2 and 3 of this report. Annex 2 describes the construction of individual parts of the fuel elements and the results of the chemical analyses. Annex 3 shows the microstructure of uranium in the fuel element.

  9. Project RA Research nuclear reactor - Annual report 1993 with comparative review for the period 1991 - 1993

    International Nuclear Information System (INIS)

    1993-12-01

    Research reactor RA Annual report for year 1993 is divided into two main parts to cover: (1) operation and maintenance and (2) activities related to radiation protection. First part includes 8 annexes describing reactor operation, activities of services for maintenance of reactor components and instrumentation, financial report and staffing. The ninth separate annex deals with the feasibility of RA reactor applications. Second part of the report is devoted to radiation protection issues and contains 4 annexes with data about radiation control of the working environment and reactor environment, description of decontamination activities, collection of radioactive wastes, and meteorology data [sr

  10. Radioactivity in the environment of the RA nuclear reactor in Vinca for the period 1977-1980. Material prepared for the RA reactor safety report; Radioaktivnost okoline nuklearnog reaktora RA u Vinci u periodu 1977-1980, Materijal pripremljen za izradu Sigurnosnog izvestaja za reaktor RA

    Energy Technology Data Exchange (ETDEWEB)

    Ajdacic, N; Martinc, R [Institute of nuclear sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

    1980-12-15

    Review of the environmental monitoring data presented in this report is prepared for the RA reactor safety report. These data resulted from four-year monitoring of precipitations and deposited dust. Measurements were done daily. In addition to these data, tables contain mean daily values, total monthly values of beta activities of precipitation from 1977 - 1980. Radioactivity control of the RA reactor environment showed that there was no significant discrepancy compared to the mean values for several years, apart from seasonal variations and meteorological influences. In the period from October 1976 to mid 1978 a number of higher values were recorded probably due to nuclear explosions. During 1979 the general activity level was relatively low, showing increase tendency during 1980.

  11. Fast neutron flux in the RA reactor experimental channels; Fluks brzih neutrona u eksperimentalnim kanalima reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

    Raisic, N; Dobrosavljevic, N [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1961-12-15

    Fast neutron flux in the RA reactor experimental channels was determined by using threshold reaction detectors. The (n,p) type reactions S{sub 32} (n,p)P{sub 32}, and Al{sub 24} (n,p)Na{sub 24}. Prepared sulphur and phosphorous foils were placed in cadmium boxes and irradiated in experimental channels VK-5, VK-7 and VK-9. Gold foils were irradiated simultaneously for controlling the reactor power. Reactor power was 100 kW during irradiation of half an hour. Activity of P{sub 32} and S{sub 31} after reactor shutdown was measured by 4{pi} counter and three calibrated GM counters. Absolute neutron flux was determined by using thus obtained data.

  12. Determination of boron in Jabroc wood used as a shielding material in nuclear reactors

    International Nuclear Information System (INIS)

    Kamble, Granthali S.; Manisha, V.; Venkatesh, K.

    2015-01-01

    Jabroc are non-impregnated, densified wood laminates developed commercially for a wide range of industrial applications. Jabroc can be used with other neutron shielding materials such as Lead to form complex shielding structures. Its relative light weight and cleanliness in handling are additional features that make it a suitable candidate for the standard design of neutron shielding equipment. Jabroc can also be impregnated with Boron up to a maximum of 4% to be used in areas where Gamma radiation produced on Neutron capture reaches unacceptable dose rates. Boron impregnated Jabroc wood finds application in TAPS 3 and 4 as a shielding material for the Ion Chambers and the Horizontal Flux Units (HFU). The shielding property of this material is optimized by incorporating requisite amount of boron in wood. Boron content in this material has to be determined accurately prior to its use in the nuclear reactors. In this work a method was standardized to determine boron in Jabroc wood samples to check for conformance to specifications. The wood sample flakes were wetted with saturated barium hydroxide solution and dries under IR. The sample was ashed in a muffle furnace at 600℃ for 2 h

  13. Modeling of boron control during power transients in a pressurized water reactor

    International Nuclear Information System (INIS)

    Mathieu, P.; Distexhe, E.

    1986-01-01

    Accurate control instructions in a reactor control aid computer are included in order to realize the boron makeup throughput, which is required to obtain the boron concentration in the primary coolant loop, predicted by a neutronic code. A modeling of the transfer function between the makeup and the primary loop is proposed. The chemical and volumetric control system, the pressurizer, and the primary loop are modeled as instantaneous diffusion cells. The pipes are modeled as time lag lines. The model provides the unstationary boron distributions in the different elements of the setup. A numerical code is developed to calculate the time evolutions of the makeup throughput during power transients

  14. Study of the boron homogenizing process employing an experimental low-pressure bench simulating the IRIS reactor pressurizer – Part I

    International Nuclear Information System (INIS)

    Bezerra, Jair de Lima; Lira, Carlos Alberto Brayner de Oliveira; Barroso, Antonio Carlos de Oliveira; Lima, Fernando Roberto de Andrade; Bezerra da Silva, Mário Augusto

    2013-01-01

    Highlights: ► Experimental bench with test section made of transparent acrylic, simulating the pressurizer reactor IRIS. ► Workbench used to study the process of homogenization of boron in the pressurizer IRIS nuclear reactor. ► Results were obtained through videos and digital photos of the test section. - Abstract: The reactivity control of a nuclear reactor to pressurized water is made by means of controlling bars or by boron dilution in the water from the coolant of a primary circuit. The control with boron dilution has great importance, despite inserting small variations in the reactivity in the reactor, as it does not significantly affect the distribution of the neutron flux. A simplified experimental bench with a test section manufactured in transparent acrylic, was built in reduced scale as to be used in a boron homogenizing process, simulating an IRIS reactor pressurizer (International Reactor Innovative and Secure). The bench was assembled in the Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE), an entity linked to the Comissão Nacional de Energia Nuclear (CNEN), Recife – PE

  15. Study of the boron homogenizing process employing an experimental low-pressure bench simulating the IRIS reactor pressurizer – Part II

    International Nuclear Information System (INIS)

    Bezerra, Jair de Lima; Lira, Carlos Alberto Brayner de Oliveira; Barroso, Antonio Carlos de Oliveira; Lima, Fernando Roberto de Andrade; Silva, Mário Augusto Bezerra da

    2013-01-01

    Highlights: • Experimental bench with test section made of transparent acrylic, simulating the pressurizer reactor IRIS. • Workbench used to study the process of homogenization of boron in the pressurizer IRIS nuclear reactor. • Results were obtained through videos and digital photos of the test section. - Abstract: The reactivity control of a nuclear reactor to pressurized water is made by means of controlling bars or by boron dilution in the water from the coolant of a primary circuit. The control with boron dilution has great importance, despite inserting small variations in the reactivity in the reactor, as it does not significantly affect the distribution of the neutron flux. A simplified experimental bench with a test section manufactured in transparent acrylic, was built in reduced scale as to be used in a boron homogenizing process, simulating an IRIS reactor pressurizer (International Reactor Innovative and Secure). The bench was assembled in the Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE), an entity linked to the Comissão Nacional de Energia Nuclear (CNEN), Recife–PE

  16. Biomedical irradiation system for boron neutron capture therapy at the Kyoto University Reactor

    International Nuclear Information System (INIS)

    Kobayashi, T.; Kanda, K.; Ujeno, Y.; Ishida, M.R.

    1990-01-01

    Physics studies related to radiation source, spectroscopy, beam quality, dosimetry, and biomedical applications using the Kyoto University Reactor Heavy Water Facility are described. Also, described are a Nickel Mirror Neutron Guide Tube and a Super Mirror Neutron Guide Tube that are used both for the measurement of boron concentration in phantom and living tissue and for precise measurements of neutron flux in phantom in the presence of both light and heavy water. Discussed are: (1) spectrum measurements using the time of flight technique, (2) the elimination of gamma rays and fast neutrons from a thermal neutron irradiation field, (3) neutron collimation without producing secondary gamma rays, (4) precise neutron flux measurements, dose estimation, and the measurement of boron concentration in tumor and its periphery using guide tubes, (5) the dose estimation of boron-10 for the first melanoma patient, and (6) special-purpose biological irradiation equipment. Other related subjects are also described

  17. Biomedical irradiation system for boron neutron capture therapy at the Kyoto University reactor

    International Nuclear Information System (INIS)

    Kobayashi, T.; Kanda, K.; Ujeno, Y.; Ishida, M.R.

    1990-01-01

    Physics studies related to radiation source, spectroscopy, beam quality, dosimetry, and biomedical applications using the Kyoto University Reactor Heavy Water Facility are described. Also, described are a Nickel Mirror Neutron Guide Tube and a Super Mirror Neutron Guide Tube that are used both for the measurement of boron concentration in phantom and living tissue and for precise measurements of neutron flux in phantom in the presence of both light and heavy water. Discussed are: (1) spectrum measurements using the time of flight technique, (2) the elimination of gamma rays and fast neutrons from a thermal neutron irradiation field, (3) neutron collimation without producing secondary gamma rays, (4) precise neutron flux measurements, dose estimation, and the measurement of boron concentration in tumor and its periphery using guide tubes, (5) the dose estimation of boron-10 for the first melanoma patient, and (6) special-purpose biological irradiation equipment. Other related subjects are also described

  18. Project RA Research nuclear reactor - Annual report 1993 with comparative review for the period 1991 - 1993; Projekat Istrazivacki nuklearni reaktor RA - Izvestaj za 1993. godinu, uz uporedni pregled za period 1991 - 1993

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-15

    Research reactor RA Annual report for year 1993 is divided into two main parts to cover: (1) operation and maintenance and (2) activities related to radiation protection. First part includes 8 annexes describing reactor operation, activities of services for maintenance of reactor components and instrumentation, financial report and staffing. The ninth separate annex deals with the feasibility of RA reactor applications. Second part of the report is devoted to radiation protection issues and contains 4 annexes with data about radiation control of the working environment and reactor environment, description of decontamination activities, collection of radioactive wastes, and meteorology data. [Serbo-Croat] Godisnji izvestaj o radu nuklearnog reaktora RA za 1993. godinu sastoji se od dva dela: prvi deo obuhvata pogon i odzavanje reaktora RA, a drugi poslove zastite od zracenja na reaktoru RA. Prvi deo sadrzi 8 priloga, koji opisuju rad reaktora i poslove sluzbi za odrzavanje opreme i komponenti, finansijski izvestaj, kadrovsku strukturu osoblja reaktora. Poseban prilog razmatra mogucnosti koriscenja istrazivackog reaktora RA. Drugi deo izvestaja o poslovima zastite od zracenja sadrzi 4 priloga sa podacima radijacione kontrole radne sredine i okoline reaktora, opis poslova dekontaminacije i sakupljanja radioaktivnih materija, kao i meteoroloske podatke.

  19. Research nuclear reactor RA - Annual Report 1995, with comparative review for period 1991-1995; Istrazivacki nuklearni reaktor RA - Izvestaj za 1995. godinu, uz uporedni pregled za period 1991-1995

    Energy Technology Data Exchange (ETDEWEB)

    Sotic, O [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1995-12-01

    Activities related to revitalisation of the RA reactor started in 1986, were continued during period 1991-1995. All the planned actions related to renewal of the reactor components were finished. The last, and at the same time most important action, related to exchange of complete reactor instrumentation is underway, delayed. The delivery of components from USSR is late. Production of this instruments is financed by the IAEA according to the contract signed in December 1988 with Russian Atomenergoexport. According to this contract, it has been planned that the RA reactor instrumentation should be delivered to the Vinca Institute by the end of 1990. Only 56% of the instrumentation was delivered until September 1991. Since then any delivery of components to Yugoslavia was stopped because of the temporary embargo imposed by the IAEA. The existing RA reactor instrumentation was dismantled. Control and maintenance of the reactor components was done regularly and efficiently. Fuel inspection by the IAEA safeguards inspectors was done on a monthly basis. There have been on the average 47 employees at the RA reactor which is considered sufficient for maintenance and repair conditions. The problem of financing the reactor activities and maintenance remains unsolved during the period 1991-1995. This research reactor RA Annual is divided into two main parts to cover: (1) operation and maintenance and (2) activities related to radiation protection. [Serbo-Croat] U periodu 1991-1995. godina nastavljeni su poslovi na revitalizaciji reaktora RA, zapocetoj 1986. godine. Okoncan je niz zahvata na opremi postrojenja kojima ce se u narednom periodu omoguciti kontinualan i pouzdan rad ovog reaktora. Poslednji, i ujedno najveci zahvat, koji se odnosi na zamenu celokupne instrumentacije kasni zbog zastoja u isporuci opreme koja se izradjuje u Sovjetskom savezu. Izradu ove opreme finansira Medjunarodna agencija za atomsku energiju kroz ugovor sklopljen decembra 1988. godine sa moskovskom

  20. Tasks related to increase of RA reactor exploitation and experimental potential, 04. Device for transport of radioactive reactor channels and semi channels of the RA reactor, design project (I-III) Part II, Vol. II; Radovi na povecanju eksploatacionih i eksperimentalnih mogucnosti reaktora RA, 04. Uredjaj za transport aktivnih tehnoloskih kanala I semikanala reaktora RA - izrada projekta (I-III), II Deo, Album II

    Energy Technology Data Exchange (ETDEWEB)

    Pavicevic, M [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1963-07-15

    This second volume includes calculations of the main components of the transporter, description of the mechanical part of the transporter and the engineering drawing of the device for transport of radioactive reactor channels and semi channels of the RA reactor.

  1. Research reactors in Argentina

    International Nuclear Information System (INIS)

    Carlos Ruben Calabrese

    1999-01-01

    Argentine Nuclear Development started in early fifties. In 1957, it was decided to built the first a research reactor. RA-1 reactor (120 kw, today licensed to work at 40 kW) started operation in January 1958. Originally RA-1 was an Argonaut (American design) reactor. In early sixties, the RA-1 core was changed. Fuel rods (20% enrichment) was introduced instead the old Argonaut core design. For that reason, a critical facility named RA-0 was built. After that, the RA-3 project started, to build a multipurpose 5 MW nuclear reactor MTR pool type, to produce radioisotopes and research. For that reason and to define the characteristics of the RA-3 core, another critical facility was built, RA-2. Initially RA-3 was a 90 % enriched fuel reactor, and started operation in 1967. When Atucha I NPP project started, a German design Power Reactor, a small homogeneous reactor was donated by the German Government to Argentina (1969). This was RA-4 reactor (20% enrichment, 1W). In 1982, RA-6 pool reactor achieved criticality. This is a 500 kW reactor with 90% enriched MTR fuel elements. In 1990, RA-3 started to operate fueled by 20% enriched fuel. In 1997, the RA-8 (multipurpose critical facility located at Pilcaniyeu) started to operate. RA-3 reactor is the most important CNEA reactor for Argentine Research Reactors development. It is the first in a succession of Argentine MTR reactors built by CNEA (and INVAP SE ) in Argentina and other countries: RA-6 (500 kW, Bariloche-Argentina), RP-10 (10MW, Peru), NUR (500 kW, Algeria), MPR (22 MW, Egypt). The experience of Argentinian industry permits to compete with foreign developed countries as supplier of research reactors. Today, CNEA has six research reactors whose activities have a range from education and promotion of nuclear activity, to radioisotope production. For more than forty years, Argentine Research Reactors are working. The experience of Argentine is important, and argentine firms are able to compete in the design and

  2. Nuclear Reactor RA Safety Report, Vol. 12, Accidents during reactor operation; Izvestaj o sigurnosti nuklearnog reaktora RA, Knjiga 12, Akcidenti u dosadasnjem radu reaktora

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1986-11-01

    This volume includes description and analysis of typical accidents occurred during operation of RA reactor in chronological order, as follows: contamination of primary coolant circuit; leakage of heavy water from the primary coolant loop; contamination of vertical experimental channel; air contamination in the reactor building and loss of circulation of the primary coolant; failures of the vacuum pump and spent fuel packaging device; rupture of the spent fuel element cladding; dethronement's of capsule for irradiation of fuel element; rupture of the vertical experimental channel and contamination of the surroundings; swelling of a fuel element; appearance of deposits on the surface of the fuel elements cladding. The last chapter describes similar accidents occurred on nuclear reactors in the world. [Serbo-Croat] Ova knjiga sadrzi hronoloski pregled i analizu karakteristika akcidenata u dosadasnjem radu reaktora RA: kontaminacija primarnog kola hladjenja; isticanje teske vode is primarnog kola hladjenje; kontaminacija eksperimentalnog vertikalnog kanala; kontaminacija vazduha u hali reaktora i prestanak cirkulacije primarnog hladioca; otkaz vakum pumpe i uredjaja za prepakivanje ozracenog goriva; proboj kosuljice ozracenog gorivnog elementa; dehermetizacija kapsule za ozracivanje nuklearnog goriva; proboj eksperimentalnog vertikalnog kanala i kontaminacija prostorija; bubrenje gorivnog elementa; pojava taloga na kosuljicama gorivnih elemenata. Poslednje poglavlje opisuje udese na koji su se dogodili na nuklearnim reaktorima u svetu.

  3. Disassembling and modification of RA-3

    International Nuclear Information System (INIS)

    Tarizzo, R.D.

    1990-01-01

    The objective of this paper is to describe the partial disassembling and modification of RA-3, called the Modernization Project. It comprises all the technical and administrative steps directly related with this task. The improvement of RA-3 is a result of the lack of 90% enriched uranium obliging a change over to 20% enriched uranium. This brought about design modifications both in fuel elements and the reactor. The presentation of documents for the licensing authority as well as are detailed separately. The modernization project was divided in 25 tasks: 1) changing fuel element support table, 2) changing heat exchanger, 3) repairing of cooling towers, 4) repairing of primary circuit valves, 5) repairing of irradiation channels, 6) construction of a new sampler, 7) changing tangential channel, 8) cleaning and disassembling of reactor (inside), 9) changing continuous demineralizer (ion exchange column), 10) detection of failure in fuel elements, 11) modification of nuclear instrumentation, 12) modification of conventional instrumentation, 13) modification of electrical system, 14) changing telemanipulators, 15) construction of mechanism bridge, 16) changing a primary circuit valve when the heat exchanger is changed too, 17) painting ground floor, hall floor, and pump room floor with epoxy resin levelling, 18) installation of fire alarm system, 19) radioactive liquid discharge, 20) modification of secondary circuit (This task involves: a) installation of a third secondary pump, b) extension of this piping, c) installation of two 12 inch valves to the present cooling towers pools independent, d) installation of filtering system), 21) optimization hot water bed, 22) changing detector support table, 23) removal, decontamination and reinstallation of shielding, 25) changing pneumatic system

  4. Investigations of an advanced reactor with Pu fuel controlled without soluble boron

    International Nuclear Information System (INIS)

    Bergeron, J.; Lenain, R.

    1988-09-01

    This paper presents the neutronic investigations of a pressurized water reactor with spectral shift. The fuel is plutonium. The moderation ratio can vary from 1.45 to 1.15. The reactor is controlled and monitored by means of gadoliniated spectral shift rod clusters and by B4C control rod clusters enriched with boron 10. A sufficient Gd 2 O 3 content (6%) has been determined. The fissile material balance of the cycle is compiled by identifying the gains of the spectral shift: 14% of cycle time. The presence of an absorber in the spectral shift clusters is necessary to guarantee the subcriticality of the core in warm conditions (180 0 C)

  5. Independent CO2 loop for cooling the samples irradiated in the RA reactor vertical experimental channels, Task 2.50.05

    International Nuclear Information System (INIS)

    Stojic, M.; Pavicevic, M.

    1964-01-01

    This report contains the following volumes V and VI of the Project 'Independent CO 2 loop for cooling the samples irradiated in RA reactor vertical experimental channels': Design project of the dosimetry control system in the independent CO 2 loop for cooling the samples irradiated in the RA reactor vertical experimental channels, and Safety report for the Independent CO 2 loop for cooling the samples irradiated in the RA reactor vertical experimental channels [sr

  6. Radiation protection at the RA Reactor in 1985, Part -4, decontamination and treatment of solid radioactive materials for the needs of RA reactor

    International Nuclear Information System (INIS)

    Plecas, I.; Vukovic, Z.; Blagojevic, R.; Kostadinovic, A.

    1985-01-01

    This report describes the activity of the decontamination and treatment team for the needs of the RA reactor, its equipment, working conditions, methods for decontamination, means of decontamination, type and quantity of decontaminated surfaces, number of decontaminated objects, quantity of collected radioactive solid wastes, their packaging, transport to the storage place and topography od radiation field in the storage during 1985 [sr

  7. RA Research nuclear reactor, Part 1, RA reactor operation and maintenance in 1993, with comparative review for the period 1991 - 1993, Annex 3; Projekat Istrazivacki nuklearni reaktor RA - 1 Deo Pogon i odrzavanje nuklearnog reaktora RA u 1993. godini, uz uporedni pregled za period 1991 - 1993. - prilog 3

    Energy Technology Data Exchange (ETDEWEB)

    Sotic, O; Cupac, S; Sulem, B; Zivotic, Z; Mikic, N; Tanaskovic, M [Vinca Institute of Nuclear Sciences, Beograd (Serbia and Montenegro)

    1993-12-15

    RA reactor was not operated during 1993 because of the complete instrumentation exchange. Although it has been planned to exchange the complete instrumentation until the end of 1993, and to start reactor operation in the first half of 1993 this was not fulfilled because the instrumentation was not delivered until the end of 1993. Main activities during past seven years were related to construction of the emergency cooling system; repair and reconstruction of the system for handling the spent fuel and improvement of spent fuel storage conditions; exchange of the aged instrumentation. Other reactor components and systems, reactor core, primary coolant loop and gas circulation system are in good condition concerning future start-up. [Serbo-Croat] U 1993. godini reaktor nije bio u pogonu zbog zamene njegove celokupne instrumentacije. Iako je bilo planirano da se celokupna instrumentacija zameni do kraja 1993. te da reaktor pocne sa radom u prvoj polovini 1993. Ovo nije ispunjeno jer celokupna oprema nije isporucena ni do kraja 1993. godine. Osnovni zahvati koji su u proteklih sedma godina izvrseni, odnosili su se na izgradnju sistema za udesno hladjenje, rekonstrukciju sistema za rukovanje ozracenim gorivom i poboljsanje uslova za stokiranje ovog goriva, zamenu instrumentacije. Ostali sistemi reaktora, reaktorsko jezgro, primarno kolo hladjenja i sistem za cirkulaciju gasa su u dobrom stanju i mogu se nesmetano koristiti u buducem radu.

  8. RA reactor operation and maintenance, Annual report 1974; Pogon i odrzavanje reaktora RA - Izvestaj o radu u 1974. godini

    Energy Technology Data Exchange (ETDEWEB)

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

    1974-12-15

    During 1974, RA reactor was operated at nominal power for 194 days and 13 days at lower power levels. The total production was 30711 MWh which is 2.4% higher than planned. Practically there were no discrepancies from the plan. The reactor was used for irradiation and experiments according to the demand of 437 users. This report contains detailed data about reactor power and experiments performed in 1974. Total number of afety shutdowns was 11, of which 8 were caused by power cuts, and 3 due to human error. Maximum individual personnel exposure dose was 50% of the maximum permissible dose. There were no accidents during this year. Decontamination of surfaces was less than during previous years. About 805 m{sup 2} of surfaces and 178 objects were decontaminated. It was concluded that the successful operation in 1974 has a special significance taking into account the financial problems. [Serbo-Croat] Reaktor RA je u 1974. godini radio na nominalnoj snazi 194 dana i 13 dana na manjim snagama. Ukupni rad iznosio je 30711 MWh odnosno 1,4% vise od planiranog. Prakticno nije bilo odstupanja od plana rada. Reaktor je koriscen za ozracivanja i eksperimente za 437 korisnika. Ovaj izvestaj sadrzi detaljne podatke o radu i eksperimentima koji su obavljani. U toku godine bilo je 11 sigurnosnih zaustavljanja, od cega 8 zbog elektricnog napona i 3 usled greske osoblja. Ukupna doza ozracivanja ljudstva bila je manja nego prethodnih godina. Maksimalna doza po oveku bila je 50% manja od maksimalno dozvoljene doze. Nije bilo ni jednog akcidenta. Dekontaminirano je znatno manje povrsina nego ranijih godina, i sakupljeno manje otpada nego prethodnih godina, dok tecnih efluenata nije bilo. Zakljuceno je da uspesan rad reaktora u 1974. godini ima poseban znacaj kada se imaju na umu problemi finansiranja reaktora.

  9. Nuclear Reactor RA Safety Report, Vol. 9, Radiation protection; Izvestaj o sigurnosti nuklearnog reaktora RA, Knjiga 9, Zastita od zracenja

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1986-11-01

    Instrumentation for Radiation protection existing at the RA reactor is dating mostly from the period 1957-1959 when the reactor has been built. With some minor exception it was produced in USSR. Radiation protection system was constructed based on specific design project, somewhat modified original USSR project which has been indispensable because of some modification of the building design. During the past 27 years no renewal of the instrumentation was done, only maintenance was performed. Instrumentation consists of old electronic devices which caused difficulties and even prevented regular maintenance because of lack of spare parts. Instrumentation for radiation protection at the RA reactor is classified as follows: centralized dosimetry system; stationary dosimetry instrumentation, movable and personal dosimetry systems. Apart from the scheme of dosimetry instrumentation this volume includes description of radiation protection procedures; protection devices; radiation doses and dose limit data; program for environmental radioactivity control; medical control procedures. [Serbo-Croat] Instrumentacija za zastitu od zracenja koja danas postoji na reaktoru RA najvecim delom potice iz perioda 1957-1959 kada je reaktor gradjen. Sa malim izuzetcima instrumentacija je proizvedena u SSSR. Sistem za zastitu izveden je na osnovu posebnog projekta koji predstavlja modifikaciju originalnog projekta koja je bila neophodna usled modifikovanog gradjevinskog projekta. U proteklom periodu od 27 godina instrumentacija nije obnavljana vec je vrseno samo odrzavanje. Instrumentacija je izradjena u danas prevazidjenoh tehnoligiji (elektronske cevi) sto je otezavalo i skoro onemogucavalo normalno odrzavanje. Instrumentacija za zastitu od zracenja na reaktoru RA moze se podeliti na tri dela: centralizovani dozimetrijski sistem; stacionarna dozimetrijska instrumentacija; prenosna i licna dozimetrijska instrumentacija. Pored seme sistema dozimetrijske kontrole ova knjiga sadrzi opis

  10. Ventilation system in the RA reactor building - design specifications

    International Nuclear Information System (INIS)

    Badrljica, R.

    1984-09-01

    Protective role of the ventilation system of nuclear facilities involve construction of ventilation barriers which prevent release of radioactive particulates or gases, elimination od radioactive particulates and gases from the air which is released from contaminated zones into the reactor environment. Ventilation barriers are created by dividing the building into a number of ventilation zones with different sub pressure compared to the atmospheric pressure. The RA reactor building is divided into four ventilation zones. First zone is the zone of highest risk. It includes reactor core with horizontal experimental channels, underground rooms of the primary coolant system (D 2 O), helium system, hot cells and the space above the the reactor core. Second zone is the reactor hall and the room for irradiated fuel storage. The third zone includes corridors in the basement, ground floor and first floor where the probability of contamination is small. The fourth zone includes the annex where the contamination risk is low. There is no have natural air circulation in the reactor building. Ventilators for air input and outlet maintain the sub pressure in the building (pressure lower than the atmospheric pressure). This prevents release of radioactivity into the atmosphere [sr

  11. Determination of boron in graphite, boron carbide and glass by ICP-MS, ICP-OES and conventional wet chemical methods

    International Nuclear Information System (INIS)

    Venkatesh, K.; Kamble, Granthali S.; Venkatesh, Manisha; Kumar, Sanjukta A.; Reddy, A.V.R.

    2014-01-01

    Boron is an important element of interest in nuclear reactor materials due to its high neutron absorption cross section (σ 0 =3837 barns for 10 B). In the present paper, R and D work and routinely used methods have been described for the analysis of case samples (1) Graphite where boron is present at trace levels, (2) Boron Carbide having boron concentration of about 80% and (3) Glass containing 4-6 % boron. (author)

  12. Radiation protection at the RA reactor in 1984, Part II c Radioactivity control in the environment of the RA reactor, Meteorology measurements

    International Nuclear Information System (INIS)

    Grsic, Z.; Zaric, M.; Nikolic, R.; Stevanovic, M.

    1984-01-01

    During 1984, meteorology measurements were continued as a part of the environmental control of the Vinca Institute. This report covers the period from December 1983 - November 1984. Part of the meteorology measurements and data analysis is adapted to the needs of the Institute, i.e. RA reactor and some Laboratories. The objective of these activities is forming the data base for solving everyday and special problems related to control, protection and safety of Institute environment

  13. Boron analyses in the reactor coolant system of French PWR by acid-base titration ([B]) and ICP-MS (10B atomic %): key to NPP safety

    International Nuclear Information System (INIS)

    Jouvet, Fabien; Roux, Sylvie; Carabasse, Stephanie; Felgines, Didier

    2012-09-01

    Boron is widely used by Nuclear Power Plants and especially by EDF Pressurized Water Reactors to ensure the control of the neutron rate in the reactor coolant system and, by this way, the fission reaction. The Boron analysis is thus a major factor of safety which enables operators to guarantee the permanent control of the reactor. Two kinds of analyses carried out by EDF on the Boron species, recently upgraded regarding new method validation standards and developed to enhance the measurement quality by reducing uncertainties, will be discussed in this topic: Acid-Base titration of Boron and Boron isotopic composition by Inductively Coupled Plasma Mass Spectrometer - ICP MS. (authors)

  14. Implementation of a reactivity meter for the RA-6 reactor

    International Nuclear Information System (INIS)

    Herzovich, P.F.

    1991-06-01

    An 'on line' and 'off line' digital reactivity meter was developed and implemented for the RA-6 research reactor. Safety and control rod calibration will be permitted by means of this system with the same precision and faster than the period method, becoming a helpful tool to the operator in critical approach and in experimental design. (Author) [es

  15. The experimental study on the mass transfer model of boron injection for natural circular heating reactor

    International Nuclear Information System (INIS)

    Zha Meisheng; Nie Mengchen; Zhou Huizhong; Wang Liqun; Guo Weiping; Liu ZHiyong

    1989-09-01

    A pulse injection stimulus-response technique to study the boron mixing and transport performance after boron-loaded liquid was injected into the reactor core is described. The experiment was carried out in a simulation device. The simulation medium was used. The experimental results show that the lower plenum where the injection point located can be simplified to one scale inertial unit and the movement of boron mixture was only transported after it had entered into the fuel elements. The definition of boron initiative mixing fraction η is also given. By using relating data a dimensionless equation is obtained

  16. Design study of a medical reactor for Boron Neutron Capture Therapy

    International Nuclear Information System (INIS)

    Sasaki, M.; Hirota, J.; Tamao, S.; Kanda, K.; Mishima, Y.

    1992-01-01

    A new design study of a medical reactor for Boron Neutron Capture Therapy (BNCT) has been carried out. The reactor is to be used exclusively for the treatment of malignant melanoma and other cancers as well as for the further biomedical research. Main specifications of the reactor are as follows; thermal power of 2 MW, water cooling by natural convection, semitight core of triangular lattice, UO 2 fuel rod of 9.5 mm diameter and no refueling in the reactor-life. Three horizontal and one vertical neutron beam hole are to be provided to deliver thermal and epithermal neutrons. N-γ coupling Sn transport calculations indicate that the patient treatment period will be about 30 minutes with minimal fast neutron and gamma contaminants. (author)

  17. Operation and maintenance of RA Reactor, Annual report 1977; Pogon i odrzavanje reaktora RA - Izvestaj o radu u 1977. godini

    Energy Technology Data Exchange (ETDEWEB)

    Milosevic, M et al. [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1977-12-15

    During 1977, the RA Reactor was operated at nominal power of 6.5 MW for 183 days. Total production was 28582 MWh which is 10% higher than planned. Second phase of introducing the 80% enriched fuel was fulfilled according to the plan. This means that the reactor core will be filled with highly enriched fuel in 1978. Refueling was done three time during the past year. After completing the first phase of the fuel exchange which was related mostly to reactor safety, the second phase will be devoted to the more efficient increase of neutron flux . This second phase is of utmost importance because higher neutron flux will provide better and more efficient reactor application from economic point of view. This will justify the application of the new more expensive highly enriched fuel. The budget for reactor operation and maintenance is hardly enough to cover the maintenance of the components and instrumentation. During 1977 there were no accidents related nor incidents related to the instrumentation or related to radiation protection. [Serbo-Croat] Reaktor RA je u toku 1977. godine ostvario rad od 28583 MWh odnosno 183 dana rada na nominalnoj snazi, sto u odnosu na plan rada iznosi 10% vise od planiranog. Druga faza uvodjenja 80% obogacenog goriva izvrsena je prema planu sto znaci da ce se punjenje jezgra reaktora 80% gorivom zavrsiti u toku 1978. godine. Izvrsene su tri izmene goriva. Posle isteka prvog dela prelaznog rezima koji je usmeren na maksimalnu sigurnost reaktora preci ce se na drugi deo usmeren na vece i brze povecanje neutronskog fluksa. Druga faza je od izuzetnog znacaja jer ce omoguciti bolje i znatno ekonomicnije koriscenje reaktora i opravdati upotrebu novog i skupljeg goriva. Sredstva za pogon i odrzavanje reaktora RA su jedva dovoljna za odrzavanje neophodnog nivoa opreme. Akcidenata u toku 1977. godine nije bilo ni sa opremom ni u pogledu zastite od zracenja.

  18. Operation, maintenance and utilization of the RA reactor, Annual report 1978

    International Nuclear Information System (INIS)

    Milosevic, M.

    1978-12-01

    It has been planned for 1978 that the RA reactor would be operated for 158 dana at nominal power of 6.5 MW meaning production of 24 648 MWh. The plan was fulfilled since 24 652 MWh was produces. Reactor operation for 158 days is relevant to reactor operation for 200 days in the period before 1975. The reason is increased neutron flux achieved due to improved fuel management and the characteristics of the new 80% enriched fuel. At the end of 1978 the reactor core contained 45% of 80% enriched fuel elements. Increase of neutron flux has shortened the typical time needed for irradiation of the most important samples for isotope production. This significant success in reactor operation is at the same time an obligation for increasing its utilization. Some new trends proposed for increasing reactor utilization capacities were presented at the Conference on utilization of research nuclear reactors in Yugoslavia held in May 1978 [sr

  19. Feasibility study on nuclear core design for soluble boron free small modular reactor

    Energy Technology Data Exchange (ETDEWEB)

    Rabir, Mohamad Hairie, E-mail: m-hairie@nuclearmalaysia.gov.my; Hah, Chang Joo; Ju, Cho Sung [Department of NPP Engineering, KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2015-04-29

    A feasibility study on nuclear core design of soluble boron free (SBF) core for small size (150MWth) small modular reactor (SMR) was investigated. The purpose of this study was to design a once through cycle SMR core, where it can be used to supply electricity to a remote isolated area. PWR fuel assembly design with 17×17 arrangement, with 264 fuel rods per assembly was adopted as the basis design. The computer code CASMO-3/MASTER was used for the search of SBF core and fuel assembly analysis for SMR design. A low critical boron concentration (CBC) below 200 ppm core with 4.7 years once through cycle length was achieved using 57 fuel assemblies having 170 cm of active height. Core reactivity controlled using mainly 512 number of 4 wt% and 960 12 wt% Gd rods.

  20. Investigation of corrosion of materials of the irradiation device in the RA reactor

    International Nuclear Information System (INIS)

    Zaric, M.; Mance, A.; Vlajic, M.

    1963-12-01

    Devices for sample irradiation in the vertical RA reactor channels will be made of aluminium alloys. According to the regulations concerned with introducing materials into the RA reactor core, corrosion characterisation of these materials is an obligation. Corrosion properties of four aluminium alloys were investigated both in contact with stainless steel and without it. First part of this report deals with the corrosion testing of aluminium alloys in water by gravimetric and electrochemical methods. Bi-distilled water at temperatures less than 100 deg C was used. Second part is related to aluminium alloys corrosion in carbon dioxide gas under experimental conditions. The second part of research was initiated by the design of the head of the independent CO 2 loop for samples cooling [sr

  1. RA Research reactor, Annual report 1969; Istrazivacki nuklearni reaktor RA - Izvestaj za 1969. godinu - Pogon i odrzavanje

    Energy Technology Data Exchange (ETDEWEB)

    Milosevic, D et al. [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1969-12-15

    During 1969, the RA Reactor was operated at nominal power of 6.5 MW for 200 days, and 15 days at lower power levels. Total production mounted to 31131 MWh which is 3.77% higher than planned. Reactor was used for irradiation and experiments according to the demand of 463 users from the Institute and 63 external users. This report contains detailed data about reactor power and experiments performed in 1969. It is concluded that the reactor operated successfully according to the plan. If there had been no problems with power supply during last three months and Danube low water level in September and October the past year would have been the most successful up to now. The number od scram shutdowns was not higher than during past two years in spite of the difficulties in the last quarter. There were three incidents which caused higher personnel exposure during operation. One, was the destruction of the canner with silver (because the time spent in the core was too long) which caused the surface contamination of the platform, the background radiation was 10 to 100 times higher than regular. The other two cases were caused by failure of the device for handling the fuel slugs in the fuel channels during refuelling. Reactor refuelling was done four times during 1969, and 499 fresh fuel slugs were used. Refuelling applied the approach of 'mixing' the fresh fuel slugs with the 'old' fuel slugs in the fuel channel. Decontamination of surfaces was on the same level as previously in spite of the problems with silver. Since two staff members have left, the present number od employees is now the minimum needed for reactor operation and maintenance. It is stated that the operation of components and equipment is on sufficiently high level after ten years of reactor operation. The action plan for 1970 is made according to the same principles as in previous four years but the planned production is decreased to 25000 MWh, because control of important components is needed after ten

  2. Ventilation system in the RA reactor building - design specifications; Sistem ventilacije u objektu 'RA' - Tehnicki opis

    Energy Technology Data Exchange (ETDEWEB)

    Badrljica, R [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1984-09-15

    Protective role of the ventilation system of nuclear facilities involve construction of ventilation barriers which prevent release of radioactive particulates or gases, elimination od radioactive particulates and gases from the air which is released from contaminated zones into the reactor environment. Ventilation barriers are created by dividing the building into a number of ventilation zones with different sub pressure compared to the atmospheric pressure. The RA reactor building is divided into four ventilation zones. First zone is the zone of highest risk. It includes reactor core with horizontal experimental channels, underground rooms of the primary coolant system (D{sub 2}O), helium system, hot cells and the space above the the reactor core. Second zone is the reactor hall and the room for irradiated fuel storage. The third zone includes corridors in the basement, ground floor and first floor where the probability of contamination is small. The fourth zone includes the annex where the contamination risk is low. There is no have natural air circulation in the reactor building. Ventilators for air input and outlet maintain the sub pressure in the building (pressure lower than the atmospheric pressure). This prevents release of radioactivity into the atmosphere. Zastitne uloge ventilacionog sistema kod nuklearnih postrojenja obuhvataju formiranje ventilacionih barijera koje onemugucavaju sirenje radioaktivnih cestica ili gasova putem cirkulacije vazduha; eliminaciju radioaktivnih cestica i gasova iz vazduha koji se evakuise iz kontaminiranih prostora u okolinu reaktorskog postrojenja. Formiranje zastitnih ventilacionih barijera ostvaruje se obicno podelom unutrasnjosti objekta na vise ventilacionih zona razlicitih podpritisaka u odnosu na spoljni atmosferski pritisak. Celi prostor zgrade reaktora RA podeljen je u cetiri ventilacione zone. Prva zona je zona najveceg rizika, u koju spadaju reaktorsko jezgro sa horizontalnim eksperimentalnim kanalima, tehnoloske

  3. Design of boron carbide-shielded irradiation channel of the outer irradiation channel of the Ghana Research Reactor-1 using MCNP.

    Science.gov (United States)

    Abrefah, R G; Sogbadji, R B M; Ampomah-Amoako, E; Birikorang, S A; Odoi, H C; Nyarko, B J B

    2011-01-01

    The MCNP model for the Ghana Research Reactor-1 was redesigned to incorporate a boron carbide-shielded irradiation channel in one of the outer irradiation channels. Extensive investigations were made before arriving at the final design of only one boron carbide covered outer irradiation channel; as all the other designs that were considered did not give desirable results of neutronic performance. The concept of redesigning a new MCNP model, which has a boron carbide-shielded channel is to equip the Ghana Research Reactor-1 with the means of performing efficient epithermal neutron activation analysis. After the simulation, a comparison of the results from the original MCNP model for the Ghana Research Reactor-1 and the new redesigned model of the boron carbide shielded channel was made. The final effective criticality of the original MCNP model for the GHARR-1 was recorded as 1.00402 while that of the new boron carbide designed model was recorded as 1.00282. Also, a final prompt neutron lifetime of 1.5245 × 10(-4)s was recorded for the new boron carbide designed model while a value of 1.5571 × 10(-7)s was recorded for the original MCNP design of the GHARR-1. Copyright © 2010 Elsevier Ltd. All rights reserved.

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

    International Nuclear Information System (INIS)

    Peirone, M.; Coleff, A.; Sanchez, F.; Chiaraviglio, N.

    2013-01-01

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

  5. Separation process for boron isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Rockwood, S D

    1975-06-12

    The method according to the invention is characterized by the steps of preparing a gaseous mixture of BCl/sub 3/ containing the isotopes of boron and oxygen as the extractor, irradiating that mixture in the tube of the separator device by means of P- or R-lines of a CO/sub 2/ laser for exciting the molecules containing a given isotope of boron, simultaneously irradiating the mixture with UV for photodissociating the excited BCl/sub 3/ molecules and separating BCl/sub 3/ from the reaction products of photodissociation and from oxygen. Such method is suitable for preparing boron used in nuclear reactors.

  6. Description of the control and safety systems of the RA reactor

    International Nuclear Information System (INIS)

    Popovic, B.; Pesic, M.

    1962-01-01

    This report contains detailed description and scheme of the control and safety system of the RA reactor. It consists of interconnected five systems: for automated regulation; compensation rods; safety rods; power density measurement device; period meter; automated D 2 O level meter in the core. Automated regulation system is divided into two parts: basic system for reactor operation regime at power from 10kW - 10 MW and precise regulation system for operation at set-up power level up to 10 kW which is used occasionally

  7. Contamination, decontamination and radiochemical safety analyses of the RA reactor (Report 1966)

    International Nuclear Information System (INIS)

    Maksimovic, Z.

    1966-12-01

    This contract is concerned with development of methods for detection of fission products i the heavy water and quantitative radiochemical analysis for detecting one fission product which enables reliable verification of heavy water contamination by fission products and estimation of contamination level. Qualitative and quantitative radiometry measurements of fission products in water are shown on page 4. Page 6 shows study of contamination and decontamination of water on the laboratory level. Experiments have shown that the majority of fission products was adsorbed on the uranium oxide and that the iodine isotopes are partly in water (non-adsorbed). Gamma spectrometry analyses showed 131 I moves to distillate with the initial quantities of distilled water. decontamination factors compared to the total activity of fission products in distillator and distillate are not higher than ∼10 3 . Decontamination of water contaminated by uranium oxide and fission products in the distillation device of the RA reactor is shown on page 8. Experiments demanded special preparation due to high activity of uranium (1.7 g of uranium irradiated in the reactor for 10 days at neutron flux 1.10 13 n.cm 2 /s. Prior preparations for transport and dissolution of irradiated metal uranium as well as sampling were needed. Distillation was done under lower pressure and temperature to avoid possible contamination of the environment bu fission products and iodine. Decontamination factors are shown in Table. Contamination and decontamination of stainless steel on the laboratory level are described on page 5. It was found that the deposition of activity on the stainless steel plates is inhomogeneous showing that the uranium oxide and fission products are deposited on the rough metal surfaces. According to literature data and our laboratory studies decontamination was done by nitric acid solution (2MHNO 3 ). Since the heavy water system of the RA reactor was made of stainless teel (except the

  8. Results of environmental radiation monitoring and meteorology measurements (material prepared for obtaining the licence for RA reactor experimental operation)

    International Nuclear Information System (INIS)

    1980-10-01

    According to the demands for obtaining the licence for restarting the Ra reactor and the experimental operation this document includes the radiation monitoring measured data in the working space and environment of the RA reactor, i.e. Boris Kidric Institute. The meteorology measured data are included as well. All the measurements are performed according to the radiation protection program applied actually from the first reactor start-up at the end of 1959 [sr

  9. RA reactor operation and maintenance in 1990 with comparative evaluation from 1986-1990, Part 1; Deo 1 - Pogon i odrzavanje nuklearnog reaktora RA u 1990. godini, uz uporedni pregled za period 1986-1990. godina

    Energy Technology Data Exchange (ETDEWEB)

    Sotic, O; Cupac, S; Sulem, B; Zivotic, Z; Vasovic, B; Sanovic, V [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1990-12-15

    During the previous period RA reactor was not operated because the Committee of Serbian ministry for health and social care has cancelled the operation licence in August 1984. The reason was the non existing emergency cooling system and lack of appropriate filters in the special ventilation system. The new emergency cooling system and the reconstruction of the existing ventilation system were finished in 1989, the conditions for further reactor operation were fulfilled. In the meantime new licensing regulations adopted in 1988 were not demanding the mentioned conditions for reactors operated at power less than 10MW, RA reactor power being 6.5 MW. But the reactor could not be restarted due to planned renewal of the reactor instrumentation. It is planned to exchange the complete instrumentation by the end of 1991. Training program for the staff operating and maintaining the reactor components was prepared in 1985. Reconstruction, modification and construction of components demanded new documentation needed for further safe reactor operation. New version of RA reactor safety report was finished in 1986 according to the recommendations of IAEA and licensing regulations of Yugoslavia. In 1989, new documents were written covering regulations and instructions for reactor operation. The new reactor experimental loop was designed in 1986, and constructed and tested in 1990. All the reactor components were maintained by specific reactor services. Financing of the reactor remains a permanent problem. [Serbo-Croat] U proteklom periodu reaktor RA nije bio u pogonu zato sto je 30. jula 1984. godine Republicki komitet za zdravlje i socijalnu politiku republike Srbije, zabranio njegov rad zbog toga sto reaktor ne poseduje sistem za udesno hladjenje i ne poseduje odgovarajuce filtere u sistemu specijalne ventilacije. Radovi na izgradnji sistema za udesno hladjenje i rekonstrukciji postojeceg sistema specijalne ventilacije zavrseni su 1989. godine. Uslovi za nastavak rada reaktora

  10. Decontamination of the RA reactor heavy water system, Annex 9

    International Nuclear Information System (INIS)

    Maksimovic, Z.B.; Nikolic, R.M.; Marinkovic, M.D.; Jelic, Lj.M.

    1963-01-01

    Both stainless steel and aluminium parts of the RA reactor heavy water system system were decontaminated as well as the heavy water itself. System was contaminated with 60 Co. Decontamination factor was determined by activity measurements during distillation. Concentration of the corrosion products in the heavy water was measured by spectrochemical analysis, and found to be 0.1 - 1 mg/l. Chemical analyses of the aluminium and stainless steel surfaces showed that cobalt was adsorbed on the aluminium oxide layer. Water solution of 7%H 3 PO 4 + 2% CrO 3 was used for decontamination of the heavy water system and distillation device. This was found to be the most efficient solvent which does not affect stainless steel corrosion. Decontamination factors achieved were from 60 - 100. Decontamination results enabled determining the distribution of cobalt in the system: 10 Ci on the stainless steel parts, 50 Ci in the heavy water; and above 600 Ci on the fuel and experimental channels. Specific activity of 60 Co was calculated to be 15 Ci/g on the reactor channels, 8 Ci/g on the stainless steel parts and 3 Ci/g in the heavy water. Decontamination of the aluminium parts was not done because it was considered it could initiate corrosion. Since the efficiency of distillation is increased it was expected that permanent distillation would remove most of the activity in the reactor channels

  11. Accident conditions analysis of spent fuel storage pool RA research reactor in Vinca; Analiza udesnih stanja u odlagalistu isluzenog goriva istrazivackog rektora RA u Vinci

    Energy Technology Data Exchange (ETDEWEB)

    Jovic, V; Jovic, L [Institute of Nuclear Sciences VINCA, Belgrade (Serbia and Montenegro)

    2000-07-01

    Based on Safety analysis of the spent fuel pool RA research reactor in Vinca, conditions and possibilities accident sequences in present configuration storage facility are considered (author) [Serbo-Croat] Na osnovu Analize sigurnosti odlagalista isluzenog goriva istrazivackog reaktora RA u Vinci razmatraju se uslovi i mogucnosti pojave udesnih stanja u postojecoj konfiguraciji odlagalista (author)

  12. Online monitoring and diagnostic system on RA-6 nuclear reactor

    International Nuclear Information System (INIS)

    Garcia Peyrano, O. A.; Marticorena, M.; Koch, R. G.; Martinez, J. S; Berruti, G. E.; Nunez, W. M.; Gonzales, L. A.; Tarquini, L. D.; Sotelo, J. P

    2009-01-01

    This paper presents the Online Automatic Monitoring and Diagnostic System for mechanical components, installed on RA-6 Nuclear Reactor (San Carlos de Bariloche, Argentina). This system has been designed, installed and set-up by the Vibrations and Mechatronics Laboratory (Centro Atomico Bariloche, Comision Nacional de Energia Atomica) and Sitrack.com Argentina SA. This system provides an online mechanical diagnostic of the main reactor components, allowing incipient failures to be early detected and identified, avoiding unscheduled shut-downs and reducing maintenance times. The diagnostic is accomplished by an online analysis of the vibratory signature of the mechanical components, obtained by vibrations sensors on the main pump and the decay tank. The mechanical diagnostic and the main operational parameters are displayed on the reactor control room and published on the internet. [es

  13. Description of the control and safety systems of the RA reactor; Opis sistema za upravljanje i sigurnosnu zastitu RA

    Energy Technology Data Exchange (ETDEWEB)

    Popovic, B; Pesic, M [Institute of Nuclear Sciences Boris Kidric, Reaktor RA, Vinca, Beograd (Yugoslavia)

    1962-07-01

    This report contains detailed description and scheme of the control and safety system of the RA reactor. It consists of interconnected five systems: for automated regulation; compensation rods; safety rods; power density measurement device; period meter; automated D{sub 2}O level meter in the core. Automated regulation system is divided into two parts: basic system for reactor operation regime at power from 10kW - 10 MW and precise regulation system for operation at set-up power level up to 10 kW which is used occasionally.

  14. Dosimetry and technical radiation protection at the RA Reactor - Report for 1977, Annex V; Prilog V - Dozimetrija i tehnicka zastita od zracenja kod reaktora RA - Izvestaj za 1977. godinu

    Energy Technology Data Exchange (ETDEWEB)

    Ninkovic, M et al. [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1977-12-15

    This report includes data about the level of gamma and neutron radiation, and level of contamination in the working environment at the RA reactor, data about collective and individual exposure of the staff to radiation, data about contamination and decontamination as well as radioactive waste. During 1977, at the RA reactor there was no accident that would cause significant exposure of tf the staff or contamination of the working space and the environment of the reactor. [Serbo-Croat] Ovaj Izvestaj sadrzi podatke o nivou gama i neutronskog zracenja i stepenu kontaminacije radne sredine, podatke o individualnom i kolektivnom izlaganju zracenju radnog osoblja, podatke o kontaminaciji i dekontaminaciji kao i o radioaktivnom otpadu. U toku 1977. godine, na reaktoru RA nije bilo akcidenata vecih razmera koji bi za posledice imali znacajnije ozracivanje radnog osoblja i kontaminaciju radne sredine i okoline.

  15. Investigation of corrosion of materials of the irradiation device in the RA reactor; Ispitivanje korozije materijala uredjaja za ozracivanje na reaktoru RA

    Energy Technology Data Exchange (ETDEWEB)

    Zaric, M; Mance, A; Vlajic, M [Institute of Nuclear Sciences Vinca, Beograd (Serbia and Montenegro)

    1963-12-15

    Devices for sample irradiation in the vertical RA reactor channels will be made of aluminium alloys. According to the regulations concerned with introducing materials into the RA reactor core, corrosion characterisation of these materials is an obligation. Corrosion properties of four aluminium alloys were investigated both in contact with stainless steel and without it. First part of this report deals with the corrosion testing of aluminium alloys in water by gravimetric and electrochemical methods. Bi-distilled water at temperatures less than 100 deg C was used. Second part is related to aluminium alloys corrosion in carbon dioxide gas under experimental conditions. The second part of research was initiated by the design of the head of the independent CO{sub 2} loop for samples cooling. [Serbo-Croat] Uredjaji za ozracivanje u vertikalnim kanalima reaktora RA, bice napravljeni od legura aluminjuma. Prema propisima o unosenju materijala u RA reaktor materijali se moraju prethodno ispitati i sa stanovista korozije. Ispitivane su korozione pojave na cetiri aluminjumske legure sa i bez kontakta sa nerdjajucim celikom. Prvi deo ovog rada tretira pitanje korozije legura aluminijuma u vodi gravimetrijskim i elektrohemijskim metodama. Koriscena je bidestilovana voda na temperaturi do 100 deg C. Drugi deo se odnosi na ispitivanje ponasanja legura aluminijuma u gasovitom ugljen dioksidu pod uslovima eksperimenta. Drugi deo istrazivanja izvrsen je za potrebe izgradnje glave petlje nezavisnog kola za hladjenje uzoraka gasovitim CO{sub 2}.

  16. RA-6 reactor's probabilistic safety evaluation. Identification and selection of starting events

    International Nuclear Information System (INIS)

    Kay, J.; Chiossi, C.; Felizia, E.; Vallerga, H.; Kalejman, G.; Navarro, R.; Caruso, G.J.

    1987-01-01

    A summary of the 'Identification and selection of starting events' stage of the previous probabilistic safety evaluation of RA-6 reactor is presented. This evaluation was performed to verify if the safety criteria required for the licensing of RA-6 are met and to promote the diffusion of its meaning and usefulness with educational purposes. At this stage the starting events of RA-6 are determined and the probability that such events occur is calculated. The identification and selection of starting events is performed in two steps: determination of proposed starting events and determination of postulated starting events. The proposed starting events are determined by means of the master logic diagram (MLD) method, while the postulated starting events are obtained by grouping the proposed starting events. The simplifying hypothesis required for the application of MLD to the reactor are also formulated. The probability that the proposed and postulated starting events occur is afterwards calculated, adopting different fault models, in accordance with the nature of events that are considered. Conservative hypothesis on the characteristics of these events and the uncertainty of parameter values of those models are also formulated. The numerical values of the above mentioned probabilities are obtained by giving the parameters suitable values that are extracted from specialized publications. (Author)

  17. Design, Fabrication and Performance of Boron-Carbide Control Elements

    International Nuclear Information System (INIS)

    Brammer, H.A.; Jacobson, J.

    1964-01-01

    A control blade design, incorporating boron-carbide (B 4 C) in stainless-steel tubes, was introduced into service in boiling water reactors in April 1961. Since that time this blade has become the standard reference control element in General Electric boiling-water reactors, replacing the 2% boron-stainless-steel blades previously used. The blades consist of a sheathed, cruciform array of small vertical stainless-steel tubes filled with compácted boron-carbide powder. The boron-carbide powder is confined longitudinally into several independent compartments by swaging over ball bearings located inside the tubes. The development and use of boron-carbide control rods is discussed in five phases: 1. Summary of experience with boron-steel blades and reasons for transition to boron-carbide control; 2. Design of the boron-carbide blade, beginning with developmental experiments, including early measurements performed in the AEC ''Control Rod Material and Development Program'' at the Vallecitos Atomic Laboratory, through a description of the final control blade configuration; 3. Fabrication of the blades and quality control procedures; 4. Results of confirmatory pre-operational mechanical and reactivity testing; and 5. Post-operational experience with the blades, including information on the results of mechanical inspection and reactivity testing after two years of reactor service. (author) [fr

  18. Criticality safety studies involved in actions to improve conditions for storing 'RA' research reactor spent fuel

    International Nuclear Information System (INIS)

    Matausek, M.; Marinkovic, N.

    1998-01-01

    A project has recently been initiated by the VINCA Institute of Nuclear Sciences to improve conditions in the spent fuel storage pool at the 6.5 MW research reactor RA, as well as to consider transferring this spent fuel into a new dry storage facility built for the purpose. Since quantity and contents of fissile material in the spent fuel storage at the RA reactor are such that possibility of criticality accident can not be a priori excluded, according to standards and regulations for handling fissile material outside a reactor, before any action is undertaken subcriticality should be proven under normal, as well as under credible abnormal conditions. To perform this task, comprehensive nuclear criticality safety studies had to be performed. (author)

  19. Corrosion of aluminium-clad spent fuel at RA research reactor

    International Nuclear Information System (INIS)

    Pesic, M.; Maksin, T.; Dobrijevic, R.; Idjakovic, Z.

    2003-01-01

    Almost 95% of all spent fuel elements of the RA research reactor in the Vinca Institute of Nuclear Sciences, Belgrade, Serbia and Montenegro, are stored in 30 aluminium barrels and about 300 stainless steel channel-holders in the temporary spent fuel storage water pool. The first activities of sludge and water samples, taken from the pool, were measured in 1996-1997 and were followed by analysis of chemical composition of samples. Visual inspections of fuel elements in some stainless steel tubes and of the fuel channels stored in the reactor core have shown that some deposits cover aluminium cladding. Stains and surface discoloration are noted on many of the spent fuel elements that were examined visually during the core unloading and inspections carried out in 1979 - 1984. Some of water samples, taken from pool, about a 150 stainless steel tubes and 16 barrels have shown very high 137-Cs activity compared to low activity measured in pool water. It was concluded that aluminium cladding of the fuel elements was penetrated due to corrosion process. Study on influence of water corrosion processes in the RA reactor storage pool was started within the framework of the IAEA CRP 'Corrosion of Research Reactor Aluminium-Clad Spent Fuel in Water' in 2002. The first test rack with various aluminium and stainless steel coupons, supplied by the IAEA, was immersed in the pool already in 1996. New racks were immersed in 2002 and 2003. The rack immersed in 1996 was taken out from the pool in 2002 and the rack immersed in 2002 was taken out in 2003. Results of the examination of these racks, carried out according to the strategy and the protocol, proposed by the IAEA, are described in this paper. (author)

  20. Dosimetry and radiation shielding at the RA reactor, Annual report 1975, Annex 5

    International Nuclear Information System (INIS)

    Ninkovic, M.

    1976-01-01

    In the working environment at the RA reactor, the level of gamma radiation is measured continuously by the built-in stationary system. According to the needs, measurement are done in the reactor hall every day. The level of gamma radiation is measured separately in typical points when the reactor is operated at nominal power and during intervals between two operating campaigns. The level of neutron radiation is measured according to the needs by means of a mobile spherical neutron detector. These measurements are done in the reactor hall around the horizontal experimental channels. Measured values of neutron radiation are three times lower than the relevant levels of gamma radiation [sr

  1. RA Research reactor, Annual report 1970 - Operation and maintenance

    International Nuclear Information System (INIS)

    Milosevic, D. et al.

    1970-12-01

    During 1970, the RA Reactor was operated at nominal power of 6.5 MW for 160 days, and 40 days at lower power levels. Total production mounted to 25968 MWh which is 3.87% higher than planned. The action plan was changed compared to the previous years because of sending the heavy water to France for re-concentration. Isotopic concentration of the heavy water was decreased to 99.05% and now after re-concentration it is 99.96%. Discrepancy from the action plan, in September was caused by the delay return of the heavy water for administrative and transportation difficulties. The restart of the reactor in September was postponed because the cladding of one fuel element was damaged immediately after the start-up, and the reactor had to be shutdown. In October and November reactor was in operation 28 and 25 days respectively which enabled to make up for the lost time. Reactor was used for irradiation and experiments according to the demand of 390 users, 340 from the Institute and 50 external users. This report contains detailed data about reactor power and experiments performed in 1969. It is concluded that the reactor operated successfully according to the plan. Shorter interruptions were caused only by difficulties with water supply pipes and sliding of the soil. Reactor was only twice scram shutdown because of the false signals caused by failures of the electronic control instrumentation. the period when reactor was not in operation was used for inspection of the reactor vessel internals. By using special TV cameras and telescopes, it was found that the there are no signs of corrosion on the reactor vessel, e.e. that the internals are in a very good state. Simultaneously, connection for the pipes of future emergency core cooling system were constructed. During 1970, the spent fuel was repacked from fuel channels into special aluminium casks. Four casks containing 660 fuel slugs was deposited int the storage pool No.4. There is now 18 casks with 2951 spent fuel slugs in

  2. Experimental verification of methods for gamma dose rate calculations in the vicinity of containers with the RA reactor spent fuel elements

    International Nuclear Information System (INIS)

    Milosevic, M.; Cupac, S.; Pesic, M.

    2005-01-01

    The methodology for equivalent gamma dose rate determination on the outer surface of existing containers with the spent fuel elements of the RA reactor is briefly summarised, and experimental verification of this methodology in the field of gamma rays near the aluminium channel with spent fuel elements lifted from the stainless steel containers no. 275 in the RA reactor hall is presented. The proposed methodology is founded on: the existing fuel burnup data base; methods and models for the photon source determination in the RA reactor spent fuel elements developed in the Vinca Institute, and validated Monte Carlo codes for the equivalent gamma dose rate calculations. (author) [sr

  3. Activities needed for exploitation of the RA reactor I-IV, Part III, IZ-093-0103-1961; Radovi za potrebe eksploatacije raktora RA - I-IV - III deo, IZ-093-0103-1961

    Energy Technology Data Exchange (ETDEWEB)

    Jurida, V [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1961-12-15

    For the purpose of designing the low-temperature loop at the RA reactor, a list of materials that would be irradiated in the reactor was made. This document includes a review of the radiochemistry data for the listed materials and data about thermal stability of the mentioned materials. Calculation of heat generated in listed samples was based on the theoretical and experimental results of radiation characteristics of the RA reactor. Maximum temperature values in the samples without forced cooling are calculated. [Serbo-Croat] Za potrebe projektovanja niskotemperaturne petlje na reaktoru RA nacinjen je pregled materijala za ozracivanje u reaktoru. Ovaj dokument sadrzi pregled radiajaciono hemijskih podataka za navedene materijale i podatke o termickoj stabilnosti pomenutih materijala. Toplota generisana u navedenim uzorcima racunata je uzimajuci u obzir osnovne podatke teorijske i eksperimentalne rezultate odredjivanja karakteristika zracenja u reaktoru. Izracunate su maksimalne temperature u uzorcima bez prinudnog hladjenja.

  4. Corrosion of aluminium alloy test coupons in water of spent fuel storage pool at RA reactor

    International Nuclear Information System (INIS)

    Pesic, M.; Maksin, T.; Jordanov, G.; Dobrijevic, R.

    2004-12-01

    Study on corrosion of aluminium cladding, of the TVR-S type of enriched uranium spent fuel elements of the research reactor RA in the storage water pool is examined in the framework nr the International Atomic Energy Agency (IAEA) Coordinated Research Project (CRP) 'Corrosion of Research Reactor Clad-Clad Spent Fuel in Water' since 2002. Standard racks with aluminium coupons are exposed to water in the spent fuel pools of the research reactor RA. After predetermined exposure times along with periodic monitoring of the water parameters, the coupons are examined according to the strategy and the protocol supplied by the IAEA. Description of the standard corrosion racks, experimental protocols, test procedures, water quality monitoring and compilation of results of visual examination of corrosion effects are present in this article. (author)

  5. Detection of a leaking boron-carbide control rod in a TRIGA Mark I reactor

    Energy Technology Data Exchange (ETDEWEB)

    Blotcky, A J; Arsenault, L J [General Medical Research, Veterans Administration Hospital, Omaha (United States)

    1974-07-01

    During a routine quarterly inspection of the boron-carbide control rods of the Omaha Veterans Administration Hospital 18 kW Triga Mark I reactor, a pin hole leak was detected approximately 3 mm from the chamfered edge. The leak was found by observing bubbles when the rod was withdrawn from the reactor tank for visual observation, and could not be seen with the naked eye. This suggests that pin hole leaks could occur and not be visually detected in control rods and fuel elements examined underwater. A review of the rod calibrations showed that the leak had not caused a loss in rod worth. Slides will be presented showing the bubbles observed during the inspection, together with an unmagnified and magnified view of the pin hole. (author)

  6. Detection of a leaking boron-carbide control rod in a TRIGA Mark I reactor

    International Nuclear Information System (INIS)

    Blotcky, A.J.; Arsenault, L.J.

    1974-01-01

    During a routine quarterly inspection of the boron-carbide control rods of the Omaha Veterans Administration Hospital 18 kW Triga Mark I reactor, a pin hole leak was detected approximately 3 mm from the chamfered edge. The leak was found by observing bubbles when the rod was withdrawn from the reactor tank for visual observation, and could not be seen with the naked eye. This suggests that pin hole leaks could occur and not be visually detected in control rods and fuel elements examined underwater. A review of the rod calibrations showed that the leak had not caused a loss in rod worth. Slides will be presented showing the bubbles observed during the inspection, together with an unmagnified and magnified view of the pin hole. (author)

  7. Regulations for the maintenance division of the RA reactor, Annex 6; Prilog 6 - Pravilnik poslovanja Odelenja odrzavanja i remonta reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

    Badrljica, R [Reaktor RA, Odelenje odrzavanja, Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1965-12-15

    The regulations for the Division of reactor maintenance include the organizational scheme, tasks of the Division, and operation procedures for all the staff members. [Serbo-Croat] Pravilnik o radu Odelenja za odrzavanje reaktora RA sadrzi opis organizacione strukture sluzbe, zadataka Odelenja, organizacije rada, nacin poslovanja za sve saradnike Odelenja.

  8. Operation and maintenance of the RA reactor, Report on operation in 1966, task 6.08

    International Nuclear Information System (INIS)

    Milosevic, D. and others

    1966-12-01

    During 1966, RA reactor was operated at nominal power for 196 days and 28 days at lower power levels. The total production was 31015 MWh which is 3% higher than planned. Practically there were no discrepancies from the plan. The reactor was used for irradiation and experiments according to the demand of 644 users, of which 516 were from the Institute. This report contains detailed data about reactor power and experiments performed in 1966, and a chart showing discrepancies from the plan. data concerned about the utilization of reactor experimental channels are included as well. Total number of safety shutdowns was 37, of which 20 were caused by power cuts, 10 due to voltage instabilities, 4 due to human error and 3 due to failures of instrumentation. These data are compared to safety shutdown data of previous few years. There have been no accidents which could cause any significant effects. The incidents occurred during this year are described in detail. Detailed data concerning exposure of the personnel are part of this report

  9. Regulations and instructions for RA reactor operation; Propisi i uputstva za pogon reaktora 'A'

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1989-07-01

    This regulatory guide consists of following 4 chapters: Description of the RA reactor, organization scheme, regulations for performing experiments; Regulations for staff on duty; Instructions for operating the vacuum systems, heavy water and helium systems; and evacuation in case of accident. [Serbo-Croat] Ovaj pravilnik sadrzi sledeca 4 poglavlja: Opis reaktora RA, sema organizacije rada, propisi za izvodjenje eksperimenata; Pravilnik za rad dezurnog osoblja; Uputstva za rada sa vakuum sistemima, sistemom teske vode, sistemom helijuma; evakuacija u slucaju udesa.

  10. Operation and maintenance of the RA reactor in 1965

    International Nuclear Information System (INIS)

    Milosevic, D.

    1966-01-01

    It has been planned for 1965 that the RA reactor would be operated each month for 20 days at nominal power of 6.5 MW, at lower power for 5 days, meaning production of 27 400 MWh. The plan was fulfilled since reactor produced 28809 MWh, i.e. 5% more than planned. Reactor was used for irradiation in the vertical experimental channels according to the demand of 1264 users from the Institute and 191 external users. Two groups of experiments done: at nominal power simultaneously with isotope production and experiments which demanded particular power levels and temperatures. Three fuel exchanges were done during this year, meaning that 40 fuel channels were changed in total. Vertical experimental channels VEK-1 and VEK-9 having diameter 100 mm were changed by channels having diameter 50 mm and shortened by 435 mm. Channel VEK-5 with diameter 110 mm was changed shortened by 430 mm. This enabled better fuel economy, the burnup was increased from 4500 MWd/t to 5000 MWd/t. This report contains the action plan for 1966

  11. Safety analysis for testing operation of the RA reactor in the Boris Kidric Institute, Vinca; Analiza sigurnosti rada reaktora 'RA' za probni rad u Institutu za nuklearne nauke 'Boris Kidric' - Vinca

    Energy Technology Data Exchange (ETDEWEB)

    Milosevic, M et al. [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1980-09-15

    This safety report covers detailed description of the RA reactor core, reactor components, coolant system, control system, safety system, reactor building including site characteristics. A separate chapter is devoted to radiation protection and radioactive waste management. Organizational structure od the reactor staff as well as training program are included. The last chapter includes detailed emergency plans for three accidents classified in three categories. [Serbo-Croat] Ovaj izvestaj sadrzi detaljan opis reaktora RA, sistema za hladjenje, kontolno-sigurnosnog sistema, elektricnog sistema, zgrade sa instalacijama, ukljucujuci karakteristike lokacije. Posebno poglavlje opisuje sistem zastite od zracenja i rukovanje radioaktivnim otpadom. Opisana je organizacija rada i program obuke osoblja. Poslednje poglavlje sadrzi detaljan plan mera za slucaj udesa klasifikovanih u tri kategorije.

  12. Operational report, Advantages of gradual introducing of highly enriched fuel into the RA reactor core from economic aspect and users needs; Radni izvestaj, Prednost postupka parcijalnog uvodjenja visokoobogacenog goriva u reaktor RA sa aspekta ekonomicnosti i potreba korisnika

    Energy Technology Data Exchange (ETDEWEB)

    Martinc, R et al. [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1976-10-14

    The possibility of increasing the neutron flux in the RA reactor was considered for a number of years. The possibilities of reactor reconstruction are not realistic and they should be disregarded. The possibility that remains is to achieve higher neutron flux by improving the fueling scheme and above all by introducing highly enriched fuel into the reactor core. Decision to purchase highly enriched fuel was quicker due to the fact that the 2% enriched uranium fuel is not fabricated any more. There are two procedures for exchanging the fuel in the reactor core: a) removal of partially spent 2% enriched fuel and formation of the core with fresh highly enriched fuel; b) gradually introducing the new fuel into the existing RA reactor core according to a special transfer regime. This report includes some comparative analyses of these two procedures from both economic point of view and the needs of users, as well as some technical conditions. These results are in favour of gradual introducing of new fuel into the reactor core. relevant direct savings amount to 3 000 000 dinars. Some of the most important advantages cannot be estimated in this way. This report does not cover the safety analyses results which are presented in a series of other papers. [Serbo-Croat] Vec vise godina razmatra se mogucnost za povecanje neutronskog fluksa u reaktoru RA. Mogucnosti za rekonstrukciju reaktora RA u tom smislu su minimalne i realno ih treba odbaciti. Prema tome preostaje da se povecanje neutronskog fluksa postigne usavrsavanjem seme izmene goriva, a pre svega uvodjenjem goriva sa visokim stepenom obogacenja u reaktor RA. Donosenje odluke o nabavci visokoobogacenog goriva i njegovom uvodjenju u reaktor ubrzano je i cinjenicom da se staro 2% obogaceno uransko gorivo vise ne proizvodi. Postoje dva postupka za prevodjenje reaktora na ovo gorivo: a) Uklanjanjem poluistrosenog 2% obogacenog goriva iz reaktora i formiranjem jezgra iskljucivo od svezeg visokoobogacenog goriva, b

  13. A technique to prepare boronated B72.3 monoclonal antibody for boron neutron capture therapy

    International Nuclear Information System (INIS)

    Ranadive, G.N.; Rosenzweig, H.S.; Epperly, M.W.

    1993-01-01

    B72.3 monoclonal antibody has been successfully boronated using mercaptoundecahydro-closo-dodecaborate (boron cage compound). The reagent was incorporated by first reacting the lysine residues of the antibody with m-maleimidobenzoyl succinimide ester (MBS), followed by Michael addition to the maleimido group by the mercapto boron cage compound to form a physiologically stable thioether linkage. Boron content of the antibody was determined by atomic absorption spectroscopy. For biodistribution studies, boronated antibody was radioiodinated with iodogen. 125 I-labeled and boronated B72.3 monoclonal antibody demonstrated clear tumor localization when administered via tail vein injections to athymic nude mice bearing LS174-T tumor xenografts. Boronated antibody was calculated to deliver 10 6 boron atoms per tumor cell. Although this falls short of the specific boron content originally proposed as necessary for boron neutron capture therapy (BNCT), recent calculations suggest that far fewer atoms of 10 B per tumor cell would be necessary to effect successful BNCT when the boron is targeted to the tumor cell membrane. (author)

  14. RA Reactor operation and maintenance (I-IX), Part III, Task 3.08/04-02 Refurbishment of the electrical equipment; Pogon i odrzavanje reaktora RA (I-IX), III Deo, Zadatak 3.08/04-02 Remont elektro opreme

    Energy Technology Data Exchange (ETDEWEB)

    Zecevic, V; Nikolic, M; Poznanovic, B; Rajic, M [Institute of Nuclear Sciences Boris Kidric, Reaktor RA, Vinca, Beograd (Serbia and Montenegro)

    1963-12-15

    This volume contains detailed action plan for repair of electrical equipment of the RA reactor, the list of electrical equipment parts which were either repaired or exchanged for improvement of their performance. Detailed work describing the repair and maintenance work done of the listed equipment is part of this report. Equipment related to dosimetry and control systems are included as well.

  15. Preparation of mandatory documentation before the start up of the RA-0 `zero power` nuclear reactor at Cordoba National University; Preparacion de la documentacion mandatoria para la puesta en marcha del reactor nuclear RA-0 en la Universidad Nacional de Cordoba

    Energy Technology Data Exchange (ETDEWEB)

    Martin, H R; Keil, W M; Pezzi, N

    1992-12-31

    Before the start up of the RA-0 `zero power` nuclear reactor installed at Cordoba National University, it was necessary to send to the Regulatory Authority the mandatory documentation which is required in the licensing process. With the previous papers existing for the operation in the first years of the `70, a work program for the future operational training personnel was elaborated. Based on the Authority`s applicable rules and the recommendations and with particular criteria originated in the working university conditions, the SAFETY report of RA-0 nuclear reactor was prepared. This paper describes the principal contents, items and documents involved in the safety report. (Author). [Espanol] Con motivo de la nueva puesta en servicio del REACTOR NUCLEAR RA-0 fue necesario elaborar la documentacion mandatoria requerida por la Autoridad Regulatoria Nacional. Siguiendo los lineamientos de las normas y recomendaciones vigentes e incluyendo criterios propios en lo que debia ser el contenido final de dicha documentacion, fue preparado lo que se ha denominado el INFORME DE SEGURIDAD DEL REACTOR NUCLEAR RA-0. Este documento que se describe en este trabajo, si bien contiene las habituales descripciones de todos los Informes de Seguridad, incluye otros aspectos que no siendo requeridos expresamente en el mismo, han dado una mayor coherencia a la conformacion de todos los aspectos que interrelacionan las areas de seguridad fisica, radiologica, nuclear y de control de materiales nucleares bajo salvaguardias. (Autor).

  16. Independent CO{sub 2} loop for cooling the samples irradiated in the RA reactor vertical experimental channels, Task 2.50.05; Nezavisno kolo CO{sub 2} za hladjenje uzoraka ozracivanih u vertikalnim eksperimentalnim kanalima reaktora RA, Zad. 2.50.05

    Energy Technology Data Exchange (ETDEWEB)

    Stojic, M; Pavicevic, M

    1964-07-01

    This report contains the following volumes V and VI of the Project 'Independent CO{sub 2} loop for cooling the samples irradiated in RA reactor vertical experimental channels': Design project of the dosimetry control system in the independent CO{sub 2} loop for cooling the samples irradiated in the RA reactor vertical experimental channels, and Safety report for the Independent CO{sub 2} loop for cooling the samples irradiated in the RA reactor vertical experimental channels. Ovaj izvestaj sadrzi dva albuma zadatka 'Nezavisno kolo CO{sub 2} za hladjenje uzoraka ozracivanih u vertikalnim eksperimentalnim kanalima reaktora RA', Zad. 2.50.05: Album V: Predprojekat sistema dozimetrijske kontrole u nezavisnom kolu CO{sub 2} za hladjenje uzoraka ozracivanih u VEK reaktora RA i Album VI: Izvestaj o sigurnosti za nezavisno kolo CO{sub 2} za hladjenje uzoraka ozracivanih u VEK reaktora RA.

  17. Calculation of the flow distribution for the new core of the RA-6 reactor

    International Nuclear Information System (INIS)

    Garcia, J.C.; Delmastro, Dario F.

    2007-01-01

    In this work the pressure drop, the flow distribution, effective cooling flow rate and the velocity in the subchannels that cool fuel plates for the new core of RA-6 research reactor were calculated. These calculations were performed for a flow of 340 m 3 /hr and water temperatures of 12 C degrees, of 35 C degrees and 42 C degrees. The flow distribution was calculated without considering either safety factors or geometric changes. All the calculations were performed considering the flow as isothermal. (author) [es

  18. Linear titration plot for the determination of boron in the primary coolant of a pressurized water reactor

    International Nuclear Information System (INIS)

    Midgley, D.; Gatford, C.

    1992-01-01

    A linear titration plot method has been devised for the determination of boron as boric acid in partly neutralized solution, such as occurs in the primary coolant of pressurized water reactors. The total boron and the alkali in the sample are determined simultaneously. Although it is not essential to add mannitol in this method, it is more accurate when the solution is saturated with mannitol. Comparisons are made with other modes of titration: Gran plots, first and second differential potentiometric titrations and indicator titrations. None of these gives the total boron directly in partly neutralized solutions. (author)

  19. The effects of phosphorus and boron on the behavior of a titanium-stabilized austenitic stainless steel developed for fast reactor service

    International Nuclear Information System (INIS)

    Hamilton, M.L.; Johnson, G.D.; Puigh, R.J.; Garner, F.A.; Maziasz, P.J.; Yang, W.J.S.; Abraham, N.

    1988-08-01

    Austenitic stainless steels are used for core component materials in liquid metal cooled reactors (LMRs). To extend the lifetime of LMR fuel assemblies, considerable effort was expended by the US breeder materials program to find ways to minimize radiation-induced dimensional changes (swelling and creep) and to maximize the creep rupture strength. After various elements were shown to strongly affect swelling and creep behavior, compositional modifications to a commercial grade austenitic stainless steel (AISI 316) produced an alloy with significant improvement in swelling resistance over the standard 300 series alloys. Changes were primarily in the concentrations of chromium, nickel, silicon and titanium, ASTM specification A771-83 was approved in 1983 for the new alloy, designated UNS S38660. Substantial improvement can be produced in the creep rupture behavior of this alloy. Elements such as phosphorus and boron, typically present in trace quantities, have a significant influence on the creep strength of austenitic stainless steels. Several heats of alloy S38660 were made that systematically varied the phosphorus and boron contents. Uniaxial creep tests were conducted at 704/degree/C (1300/degree/F) to evaluate the effects of these elements on the creep rate and the rupture life. The results of these tests were used to guide the production of reactor grade fuel pin cladding for further evaluations. Pressurized tube specimens were tested in the laboratory and also in a fast reactor. Results of these investigations have shown that the elements phosphorus and boron, present in minute but controlled amounts, increase both the in- reactor and ex-reactor rupture life and reduce both in-reactor swelling and creep rate. Microstructural evaluations were also conducted to help ascertain the mechanisms by which the improved properties were obtained. 41 refs., 28 figs., 3 tabs

  20. RA Research reactor, Annual report 1968 - Operation and maintenance; Istrazivacki nuklearni reaktor RA - Izvestaj za 1968. godinu - Pogon i odrzavanje

    Energy Technology Data Exchange (ETDEWEB)

    Milosevic, D et al. [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1968-12-15

    During 1968, the RA Reactor was operated at nominal power of 6.5 MW for 190 days, and during 50 days at lower power levels. Total production amounted to 31051 MWh which is 3.5% higher than planned. reactor was used for irradiation and experiments according to the demand of 600 users, of which 517 from the Institute and 83 externals users. This report contains detailed data about reactor power and experiments performed in 1968. It is concluded that the reactor operation was more successful than during previous years. There was only one longer interruption which lasted 27 hours because of the power cut on the cable for the pump station on Danube. Number of safety shutdowns were at the same level as during last year. The only significant incident in 1968 was air contamination with the radioactive argon in the reactor hall. The reactor operation was not interrupted although the hall was evacuated for two hours. The was no significant exposure of the staff. In April and September the integral dosed were higher than during other months because of the accident during refueling (mixing the slugs with irradiated and fresh fuel). There was no significant surface contamination, i.e. the decontaminated surface were negligible. Due to 'mixing' refueling scheme. [Serbo-Croat] Reaktor RA je u 1968. godini radio na nominalnoj snazi od 6,5 MW 190 dana i 50 dana na manjim snagama. Ukupni rad iznosio je 31051 MWh odnosno 3,5% vise od planiranog. Reaktor je koriscen za ozracivanja i eksperimente za 600 korisnika od cega 517 iz Instituta i 83 za korisnika izvan Instituta. Ovaj izvestaj sadrzi detaljne podatke o radu i eksperimentima koji su obavljani. Zakljucuje se da je reaktor radio uspesnije nego prethodnih godina. U toku 1968. godine samo je jedan duzi prekid u radu od 27 casova izazvan zbog proboja kablovske glave na odvodu za pumpnu stanicu na Dunavu. Sigurnosna zaustavljanja bila su na proslogodisnjem nivou. Jedini znacajniji incident u 1968. godini, bio je kontaminacija vazduha

  1. Process for manufacturing boron carbide pellets that can be used for the realization, of the control rods of water reactors

    International Nuclear Information System (INIS)

    Ballagny, Alain; Brie, Michel.

    1982-01-01

    The subject of the invention is a process for manufacturing boron carbide pellets with a boron carbide content of not less than 68% by volume and having an open porosity. This process consists in (a) preparing a mix comprising boron carbide powder of which at least 90% of the particles are under 3 μ in size, and an organic binder that can be transformed into carbon by thermal treatment, (b) compressing the hot mix thus obtained to form unbaked pellets, under a pressure of 1000 to 6000 bars, at a temperature of 80 to 250 0 C and (c) submitting the unbaked pellets thus obtained to vacuum thermal treatment to transform this binder into porous carbon. The finished pellets are used in the control rods of water reactors [fr

  2. Radiation protection at the RA Reactor in 1986, Part -2, Annex 2a, Radioactivity control of the RA reactor environment (atmospheric precipitations, dust, water, soil, plants, fruit...); Deo 2 - Prilog 2a - Kontrola radioaktivnosti okoline nuklearnog reaktora RA (padavine i slobodno natalozena prasina, vode, zemljiste, rastinje, voce...)

    Energy Technology Data Exchange (ETDEWEB)

    Ajdacic, N; Martic, M; Jovanovic, J [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1986-12-01

    Control of radioactivity in the biosphere in the vicinity of the RA reactor is part of the radioactivity control done regularly for the whole territory of the Vinca institute (report by the same authors included in this Annex). During 1986 control was conducted according to the plan until May 1, 1986 when a dramatic increase of the precipitations and all other samples from the biosphere was recorded. According to the measured data no significant changes have been found in the surroundings of the RA reactor, until April 29 1986. Since then more detailed control was conducted, the number of samples was increased, apart from standard measuring procedure of total beta activity measurements, gamma spectrometry of all samples was applied. High activity level of the following nuclides was found: Iodine, cerium,cesium, tellurium, ruthenium, barium, lanthanum, etc. As an example activity of ?1?3?1 I in one sample was 564{+-}5 kBq/m{sup 2}. [Serbo-Croat] Kontrola radioaktivnosti biosfere u okolini reaktora RA je deo kontrole radioaktivnosti koja se redovno vrsi za celokupnu teritoriju Instituta Vinca (izvestaj istih autora ukljucen je u ovaj Prilog). Tokom 1986. kontrola je ostvarivana prema planu do 1. maja 1986, kada je registrovano drasticano povecanje aktivnosti padavina i ostalih uzoraka biosfere. Prema rezultatima merenja, nisu registrovana znacajnija odstupanja u okolini reaktora RA sve do 29. aprila 1986. Od tada se vrse detaljnija merenja, broj uzoraka je uvecan, pored standardno primenjivane metode primenom merenja totalne beta aktivnosti uzoraka, svi uzorci su analizirani gama spektrometrijski. Enormno visoka kontaminacija uzoraka posle gamma spektrometrije pokazala je prisustvo aktivacionih i fisionih radionuklida medju kojima su bili: jod, cerijum, cesijum, rutenijum, barium lantan i drugi. Tako je na primer samo aktivnost I-133 iznosila 564{+-}5 kBq/m{sup 2}.

  3. Actions needed for RA reactor exploitation - I-IV, Part II, Design project VI-SA 1, Experimental loop for testing the EL-4 reactor fuel elements in the central vertical experimental channel of the RA reactor in Vinca

    International Nuclear Information System (INIS)

    Novakovic, M.

    1961-12-01

    The objective of installing the VISA-1 loop was testing the fuel elements of the EL-4 reactor. The fuel elements planned for testing are natural UO 2 with beryllium cladding, cooled by CO 2 under nominal pressure of 60 at and temperature 600 deg C. central vertical experimental channel of the RA reactor was chosen for installing a test loop cooled by CO 2 . This report contains the detailed design project of the testing loop with the control system and safety analysis of the planned experiment

  4. Service for maintenance of electronic equipment of the RA reactor, Report for 1977 - Annex IV

    International Nuclear Information System (INIS)

    Milosevic, M.

    1977-01-01

    This report describes the tasks and organizational structure of the Service for maintenance of electronic equipment of the RA reactor. The most important task of this Service is control and maintenance of the reactor control and protection instruments, operation control, and dosimetry system. Besides data about this basic instrumentation, the report includes data about control and maintenance of other electronic equipment related to the experimental devices [sr

  5. Financial report on the investment and maintenance of the RA reactor and equipment, Annex 5

    International Nuclear Information System (INIS)

    2002-01-01

    For the purpose of maintenance of the RA reactor building and equipment, Serbian Ministry of science, technology and development has approved financial support for the following: purchase and installing 12 new battery cells in the reactor building, for purchase of the missing fire protection equipment, and purchasing the material for protection of the roof of the ventilation center. All the planned tasks were fulfilled [sr

  6. The Boron Neutron Capture Therapy (BNCT) Project at the TRIGA Reactor in Mainz, Germany

    DEFF Research Database (Denmark)

    Hampel, G.; Grunewald, C.; Schütz, C.

    2011-01-01

    The thermal column of the TRIGA reactor in Mainz is being used very effectively for medical and biological applications. The BNCT (boron neutron capture therapy) project at the University of Mainz is focussed on the treatment of liver tumours, similar to the work performed at Pavia (Italy) a few ...

  7. Design project SP-RA, Construction specifications of the sanitary corridor - SP building; Idejni projekat SP-RA, Gradjevinski opis sanitarnog propusnika - objekat

    Energy Technology Data Exchange (ETDEWEB)

    Bon, B [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1956-11-09

    According to the design task the sanitary corridor satisfies the needs of both RA reactor and HL (Hot laboratory) buildings. This building is located between RA and HL buildings and is connected to both by corridors 3,3 m wide. The access to the building is from the south, i.e. from the local road in the Vinca Institute. [Serbo-Croat] Prema projektnom zadatku sanitarni propusnik zadovoljava potrebe objekata RA i HL. Zgrada je situirana izmedju ova dva objekta. Sa objektima RA i HL vezana je komunikativnim hodnikom sirine 3,3 m. Prilaz zgradi je sa juzne strane, odnosno sa internog puta Instituta Vinca.

  8. Experimental operation of the RA reactor with 4 fuel channels containing 80% enriched dispersion fuel - Operational Report; Radni izvestaj - Eksperimentalna kampanja reaktora RA sa 4 kanala sa 80% obogacenim disperzionim gorivom

    Energy Technology Data Exchange (ETDEWEB)

    Martinc, R; Milosevic, M; Cupac, S; Kozomara, S [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1976-12-15

    Start of utilization of the new 80% enriched dispersion nuclear fuel is underway in the RA reactor core. Both economic and technical analyses were in favor of introducing the new fuel elements gradually into the RA reactor core. Thus overall theoretical and experimental analyses as well as other preparations are directed to transition regime based on gradual introducing of new fuel into the core, i.e. reactor core with two types of fuel. The objective of these analyses and preparation is establishment of conditions for safe reactor operation during transition period. The analyses and preparations are almost completed. The experimental data about fuel burnup during a time period of operation at nominal power i.e. daily decrease of excess reactivity is missing. This data is needed for planning the refueling (quantity of fresh fuel and frequency of refueling) during the transient period. This data can be obtained only by normal operation of the reactor during a period of time significantly longer than the period of attaining equilibrium poisoning, as time between two D{sub 2}O condensate overflows into the RA reactor core. Thus a ten day experimental campaign was planned to be done in December 1976. This report presents the most important results of safety analyses and preparation which show that, during this experimental period, the reactor operation is absolutely safe taking into account the most important parameters influencing reactor safety, as reactivity, thermal and temperature limits for fuel and the reactor, etc. Data to be obtained during this experimental campaign are significant because they would enable definition of future supply of fresh fuel during the transition period. [Serbo-Croat] Predstoji pocetak koriscenja novog 80% obogacenog uranskog disperzionog goriva u reaktoru RA. Ekonomske i tehnicke analize dale su prednost postupku postepenog uvodjenja novog goriva u reaktor RA. Prema tome, obimne teorijske i eksperimentalne analize i druge pripreme

  9. Activity of the RA Reactor Physics group in 1980 - Definition of the Operation conditions for future safe and economical RA reactor operation with 80% enriched fuel; Prilog Ia - Rad sluzbe za fiziku reaktora RA u 1980. godini - Definisanje pogonskih uslova za dalji siguran i ekonomican rad reaktora RA sa 80% obogacenim gorivom

    Energy Technology Data Exchange (ETDEWEB)

    Martinc, R [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1980-12-15

    During 1980. the RA reactor was not in operation. That is why this period was devoted to definition of operating conditions for further reactor operation with 80% enriched fuel. The fuel elements which were in the core at the moment of shutdown in March 1979will not be used again (388 80% enriched fuel elements, and 511 2% enriched fuel elements). The reactor will be operated only with 80% enriched fuel, staring with initiat core configuration with 440 elements on the borders gradually changing to equi;librium core with 720 fuel elements. The analyses were concerned with safety issues of future operation. [Serbo-Croat] Reaktor RA tokom 1980 godine nije radio. Zbog toga je ovaj period iskoriscen za intenzivan rad na definisanju pogonskih uslova za dalji rad reaktora sa 80% obogacenim gorivom. Gorivo sa kojim je reaktor prestao da radi marta 1979. godine (388 gorivnih elemenata 80% obogacenoh i 511 elementa 2% obogaceno) nece biti vraceno u jezgro, vec ce reaktor raditi samo sa 80% obogacenim gorivom, pocev od konfiguracije sa 440 elemenata na periferiji do ravnotezne konfiguracije sa 720 elemenata. Sve nalize su se bavile sigurnosnim aspektima rada reaktora sa visokoobogacenim gorivom u jezgru.

  10. Operation, safety and utilization of the RA reactor in 1978 - Report; Prilog I - Rad, sigurnost i iskoriscenost reaktora RA u 1978. godini - Izvestaj

    Energy Technology Data Exchange (ETDEWEB)

    Martinc, R; Stanic, A [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1978-12-15

    This report includes a review of work related to development of reactor operation capacities and increase of the RA reactor safety and economic operation. Statistical data about reactor operation and utilization are included as well. Introducing of the new 80% enriched fuel into the the reactor core enabled increase of the neutron flux, i.e. increase of its production capabilities. Safety and optimization analyses concerned with introduction of the new fuel have shown that the most safe and economic procedure was gradual introducing of the highly enriched fuel. This procedure was based on the concept of mixed core configuration with 2% and 80% enriched fuel elements. By applying this original concept the following significant savings were achieved: fuel elements savings, shortening of the annual period of reactor operation, savings in spent fuel casks, electric power savings, slowing down of heavy water degradation. [Serbo-Croat] Ovaj izvestaj sadrzi pregled o radu na razvoju eksploatacionih mogucnosti i povecanju sigurnosti i ekonomicnosti reaktora RA. Prilozeni su i statisticki podaci o radu i iskoriscenosti reaktora u 1978. godini. Uvodjenje novog 80% obogacenog goriva u jezgro reaktora omogucilo je povecanje neutronskog fluksa tj. povecanje njegovoh proizvodnih mogucnosti. Sigurnosne i optimizacione analize uvodjenja novog goriva pokazale su da je nasigurniji i najekonomicniji postupak postupnog uvodjenja visokoobogacenog goriva koji se zasniva na konceptu mesane resetke sa 2% i 80% obogacenim gorivom. Ovaj originalni koncept omogucio je da se postignu znatne ustede u gorivu, skracivanje godisnjeg rada reaktora, usteda sudova za odlaganje isluzenog goriva, usteda elektricne energije, usporavanje degradacije teske vode.

  11. Spent fuel from RA reactor inspection of state and options for management

    International Nuclear Information System (INIS)

    Aden, V.G.; Bulkin, S. Yu.; Sokolov, A. V.; Matausek, M.V.; Vukadin, Z.

    2001-01-01

    About five thousand spent fuel elements from RA reactor have been stored for over 30 years in sealed aluminum barrels in the spent fuel storage pool. This way of storage does not provide complete information about the state of spent fuel elements or the medium inside the barrels, like pressure or radioactivity. The technology has been developed and the equipment has been manufactured to inspect the state of the spent fuel and to reduce eventual internal pressure inside the aluminum barrels. The realization of this technology was started in 1999 but due to political and financial difficulties was not completed. In September the year 2000 the work was restarted. Two different ways of RA reactor spent fuel elements preparation for transportation or long-term storage are considered: 'all fuel elements canning without leak-tightness testing' and 'all fuel elements leak-tightness testing'. It is believed that the first option offers several distinct advantages, which can be summarized as: greater reliability in the course of transportation or dry storage. Higher safety for workers. Lower expenditures for non-standard equipment manufacturing. Shorter duration of work. (author)

  12. Operational report, basics of the preliminary project for reconstruction of the RA reactor ventilation system

    International Nuclear Information System (INIS)

    Martinc, R.

    1982-01-01

    This report presents the summary of results needed for designing the reconstruction of the RA reactor ventilation system. The final complete report will published later, including results of possible additional analyses according to the needs of main detailed project. Due to the size of the facility the need of filters for particulates is expected in systems V-1 and V-2, as well as revision of the system V-4. Adsorption filters are not needed in case of operation under regular working conditions. It would be favorable, but not indispensable to construct an adsorption filter that could be used occasionally at the input of V-2 system under the upper water shielding. This filter would be switched on when dehermetization of the reactor is planned and increased radioactivity is indicated in the gas system or experimental space of the RA reactor as well as in case of fuel elements failure. The aim of applying filters is shortening the time these elements would spend in the hermetized reactor i.e. their fast removal from the reactor. It is indispensable to build-in 'emergency' highly efficient adsorption filters in the V-2 system which would be switched on in case of accidents that would cause fuel elements meltdown (with simultaneous accident dehermetization of the heavy water system) [sr

  13. Progress in study of a medical reactor for boron neutron capture therapy

    International Nuclear Information System (INIS)

    Sasaki, Makoto; Hirota, Jitsuya; Tamao, Shigeo; Kanda, Keiji; Mishima, Yutaka.

    1993-01-01

    A design study of a medical reactor for Boron Neutron Capture Therapy has made progress. Main specifications of the reactor are as follows; thermal power of 2 MW, water cooling by natural convection, semitight core of hexagonal lattice, UO 2 fuel rod of 9.5 mm diameter and no refueling in the reactor-life. Three horizontal and one vertical neutron beam holes are to be provided for simultaneous treatments by thermal and epithermal neutrons and for further biomedical research. The design objectives for the beam holes are to deliver the therapeutic doses in a modest time (30 to 60 min) with minimal fast neutron and gamma contaminants. The n-γ coupling Sn transport calculations have been carried out using n-21 and γ-9 group cross sections on 2-dim. practical models. The calculated results indicate that the design objectives will be achievable even if the thermal power of the reactor is reduced to 1 MW. (author)

  14. Physical and biological dosimetry at the RA-3 facility for small animal irradiation: preliminary BNCT studies in an experimental model of oral cancer

    International Nuclear Information System (INIS)

    Pozzi, Emiliano; Miller, Marcelo; Thorp, Silvia I.; Heber, Elisa M.; Trivillin, Veronica A.; Zarza, Leandro; Estryk, Guillermo; Schwint, Amanda E.; Nigg, David W.

    2007-01-01

    Boron Neutron Capture Therapy (BNCT) is a binary treatment modality based on the capture reaction that occurs between thermal neutrons and boron-10 atoms that accumulate selectively in tumor tissue, emitting high linear energy transfer (LET), short range (5-9 microns) particles (alpha y 7 Li). Thus, BNCT would potentially target tumor tissue selectively, sparing normal tissue. Herein we evaluated the feasibility of treating experimental oral mucosa tumors with BNCT at RA-3 (CAE) employing the hamster cheek pouch oral cancer model and characterized the irradiation field at the RA-3 facility. We evaluated the therapeutic effect on tumor of BNCT mediated by BPA in the hamster cheek pouch oral cancer model and the potential radio toxic effects in normal tissue. We evidenced a moderate biological response in tumor, with no radio toxic effects in normal tissue following irradiations with no shielding for the animal body. Given the sub-optimal therapeutic response, we designed and built a 6 Li 2 CO 3 shielding for the body of the animal to increase the irradiation dose to tumor, without exceeding normal tissue radio tolerance. The measured absolute magnitude of thermal neutron flux and the characterization of the beam with and without the shielding in place, suggest that the irradiation facility in the thermal column of RA-3 would afford an excellent platform to perform BNCT studies in vitro and in vivo in small experimental animals. The present findings must be confirmed and extended by performing in vivo BNCT radiobiological studies in small experimental animals, employing the shielding device for the animal body. (author) [es

  15. Tasks related to increase of RA reactor exploitation and experimental potential, 02. Verification of the system for detecting failures of the RA reactor fuel element cladding; Radovi na povecanju eksploatacionih i eksperimentalnih mogucnosti reaktora RA, 02. Provera sistema za detekciju pucanja kosuljice gorivnog elementa reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

    Pavicevic, M [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1963-07-15

    For the purpose of this task it was necessary to analyze the time dependent distribution of fission products in the fuel element and leaks through the cracks in the cladding; to calculate the quantity of solid fission products, volatile fission products and fission gases for the RA reactor; to collect the data for estimating the activity of the short-living isotopes created by neutron irradiation of D{sub 2}O; analyze the number of delayed neutrons in D{sub 2}O. Experiment were needed to estimate the distribution of Xe and Kr in the heavy water in the reactor channel and analyze the activity of D{sub 2}O and helium based on reactor operation data. For the purpose of verifying the efficiency and safety of the existing system for detecting the cracks of the fuel element cladding is presented in this report together with the review of similar systems at a number of reactors in the world.

  16. Results of environmental radiation monitoring and meteorology measurements (material prepared for obtaining the licence for RA reactor experimental operation); Rezultati merenja zracenja u okolini i rezultati meteoroloskih merenja (materijal pripremljen radi dobijanja dozvole za pustanje Reaktora RA u probni rad)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1980-10-15

    According to the demands for obtaining the licence for restarting the Ra reactor and the experimental operation this document includes the radiation monitoring measured data in the working space and environment of the RA reactor, i.e. Boris Kidric Institute. The meteorology measured data are included as well. All the measurements are performed according to the radiation protection program applied actually from the first reactor start-up at the end of 1959. [Serbo-Croat] Saglasno zahtevu za dobijanje dozvole za ponovno pustanje u probni rad reaktora RA, ovaj dokument sadrzi rezultate merenja zracenja u okolini (radnoj i zivotnoj) reaktora RA odnosno instituta 'Boris Kidric' kao i podatke o meteoroloskim merenjima. Sve merenja rade se prema programu mera zastite od zracenja koje se sprovode prakticno od prvog pustanja reaktora u rad krajem 1959. godine.

  17. Independent CO{sub 2} loop for cooling the samples irradiated in vertical experimental channels of the RA reactor, Vol. I; Nezavisno kolo CO{sub 2} za hladjenje uzoraka ozracivanih u vertikalnim eksperimentalnim kanalima reaktora RA, Album I

    Energy Technology Data Exchange (ETDEWEB)

    Pavicevic, M; Pavlovic, A [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1963-06-15

    Project 'independent CO{sub 2} loop for cooling the samples irradiated in the vertical experimental channels of the RA reactor' is presented in two volumes: volume I - head of the low temperature coolant loop for reactor RA, and volume II - Outer low-temperature reactor coolant loop. Volume I includes: the design specifications for the head of the low-temperature coolant loop, technical description, thermal calculation, calculations of mechanical loads, antireactivity and activation of the components of the coolant loop head, engineering schemes and drawings, cost estimation data. [Serbo-Croat] Projekat 'Nezavisno kolo CO{sub 2} za hladjenje uzoraka ozracivanih u vertikalnim eksperimentalnim kanalima reaktora RA', sastoji se od dva albuma: album I - Glava niskotemperaturno rashladne petlje za reaktor RA, album II - Spoljno kolo niskotemperaturne rashladne petlje za reaktora. Album I sadrzi projektni zadatak glave niskotemperaturne petlje, tehnicki opis, termicki proracun, proracun mehanickih naprezanja, antireaktivnosti i aktivacije kontrukcionih elemenata glave petlje, konstrukcione seme i crteze glave petlje, predracun.

  18. The analysis of the RA reactor irradiated fuel cooling in the spent fuel pool; Analiza hladjenja ozracenog goriva u bazenu za odlaganje reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

    Vrhovac, M; Afgan, N; Spasojevic, D; Jovic, V [Institute of nuclear sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

    1985-07-01

    According to the RA reactor exploitation plan the great quantity of the irradiated spent fuel will be disposed in the reactor spent fuel pool after each reactor campaign which will including the present spent fuel inventory increase the residual power level in the pool and will soon cause the pool capacity shortage. To enable the analysis of the irradiated fuel cooling the pool and characteristic spent fuel canister temperature distribution at the residual power maximum was done. The results obtained under the various spent fuel cooling conditions in the pit indicate the normal spent fuel thermal load even in the most inconvenient cooling conditions. (author)

  19. Work related to increasing the exploitation and experimental possibilities of the RA reactor, 05. Independent CO2 loop for cooling the samples irradiated in the RA vertical experimental channels (IIV), Part I, IZ-240-o379-1963, Vol. I, Head of the low temperature RA reactor coolant loop

    International Nuclear Information System (INIS)

    Pavicevic, M.

    1963-07-01

    The objective of the project was to design the head of the CO 2 coolant loop for cooling the materials during irradiation in the RA reactor. Six heads of coolant loops will be placed in the RA reactor, two in the region of heavy water in the experimental channels VEK-6 and four in the graphite reflector in the channels VEK-G. Materials for irradiation are metallurgy and chemical samples. In addition to the project objectives, this volume includes technical specifications of the coolant loop head, thermal calculations, calculations of mechanical stress, antireactivity and activation of the construction materials, cost estimation, scheme of the coolant loop head, diagrams of CO 2 gas temperature, thermal neutron flux distribution, design specifications of two proposed solutions for head of low temperature coolant loop [sr

  20. Tasks related to increase of RA reactor exploitation and experimental potential, 01. Designing the protection chamber in the RA reactor hall for handling the radioactive experimental equipment (I-II) Part II, Vol. II

    International Nuclear Information System (INIS)

    Pavicevic, M.

    1963-07-01

    This second volume of the project for construction of the protection chamber in the RA reactor hall for handling the radioactive devices includes the technical description of the chamber, calculation of the shielding wall thickness, bottom lead plate, horizontal stability of the chamber, cost estimation, and the engineering drawings

  1. Nuclear Reactor RA Safety Report, Vol. 5, Reactor cooling systems; Izvestaj o sigurnosti nuklearnog reaktora RA, Knjiga 5, Hladjenje reaktora i pripadajuci sistemi

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1986-11-01

    RA reactor cooling system enable cooling during normal operation and under possible accidental conditions and include: technical water system, heavy water system, helium gas system, system for heavy water purification and emergency cooling system. Primary cooling system is a closed heavy water circulation system. Heavy water system is designed to enable permanent circulation and twofold function of heavy water. In the upward direction of cooling it has a coolant role and in the downward direction it is the moderator. Separate part of the primary coolant loop is the system for heavy water purification. This system uses distillation and ion exchange processes. [Serbo-Croat] Sistemi za hladjenje reaktora RA obezbedjuju hladjenje u svim rezimima eksploatacije i potenijalno udesnim satnjim i obuhvataju: sistem tehnicke vode, sistem teske vode, gasni sistem helijuma, sistem za preciscavanje teske vode i sistem za akcidentalno hladjenje. Primarni sistem za hladjenje je zatvoreni cirkulacioni sistem teske vode. Specificnost sistema teske vode vezana je za neprekidnost cirkulacije i razlicite funkcije teske vode. U uzlaznom strujanju, teske vode ima ulogu hladioca a u silaznom ulogu moderatora. Poseban deo primarnog sistema predstavlja sistem za preciscavanje teske vode. Ovaj sistem koristi destilacioni i jonoizmenjivacki postupak.

  2. Reactivity Coefficient Calculation for AP1000 Reactor Using the NODAL3 Code

    Science.gov (United States)

    Pinem, Surian; Malem Sembiring, Tagor; Tukiran; Deswandri; Sunaryo, Geni Rina

    2018-02-01

    The reactivity coefficient is a very important parameter for inherent safety and stability of nuclear reactors operation. To provide the safety analysis of the reactor, the calculation of changes in reactivity caused by temperature is necessary because it is related to the reactor operation. In this paper, the temperature reactivity coefficients of fuel and moderator of the AP1000 core are calculated, as well as the moderator density and boron concentration. All of these coefficients are calculated at the hot full power condition (HFP). All neutron diffusion constant as a function of temperature, water density and boron concentration were generated by the SRAC2006 code. The core calculations for determination of the reactivity coefficient parameter are done by using NODAL3 code. The calculation results show that the fuel temperature, moderator temperature and boron reactivity coefficients are in the range between -2.613 pcm/°C to -4.657pcm/°C, -1.00518 pcm/°C to 1.00649 pcm/°C and -9.11361 pcm/ppm to -8.0751 pcm/ppm, respectively. For the water density reactivity coefficients, the positive reactivity occurs at the water temperature less than 190 °C. The calculation results show that the reactivity coefficients are accurate because the results have a very good agreement with the design value.

  3. Operation and maintenance of the RA reactor, Report on operation in 1966, task 6.08; Pogon i odrzavanje reaktora RA, Izvestaj o radu u 1966. god. Zadatak 6.08

    Energy Technology Data Exchange (ETDEWEB)

    Milosevic, D and others [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

    1966-12-15

    During 1966, RA reactor was operated at nominal power for 196 days and 28 days at lower power levels. The total production was 31015 MWh which is 3% higher than planned. Practically there were no discrepancies from the plan. The reactor was used for irradiation and experiments according to the demand of 644 users, of which 516 were from the Institute. This report contains detailed data about reactor power and experiments performed in 1966, and a chart showing discrepancies from the plan. data concerned about the utilization of reactor experimental channels are included as well. Total number of safety shutdowns was 37, of which 20 were caused by power cuts, 10 due to voltage instabilities, 4 due to human error and 3 due to failures of instrumentation. These data are compared to safety shutdown data of previous few years. There have been no accidents which could cause any significant effects. The incidents occurred during this year are described in detail. Detailed data concerning exposure of the personnel are part of this report.

  4. Operation, maintenance and utilization of the RA reactor, Annual report for 1980; Pogon, odrzavanje i eksploatacija reaktora RA, Izvestaj o radu u 1980. godini

    Energy Technology Data Exchange (ETDEWEB)

    Milosevic, M [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1980-12-15

    During 1980 the activities of RA reactor staff was conducted in two directions: repair works and determination of the state of the existing equipment; and preparing and constructing additional equipment and completing the documentation needed to fulfill the new legal regulations. preparation of the existing equipment for future operation was finished, but construction of the additional equipment (according to the regulations) is not done at planned rate due to different reasons such as lack of budget, administration, import. This report includes a chapter devoted to the analysis of the operation difficulties that caused prohibition of reactor operation as well as difficulties in achievement of the planned activities for 1980. Data about financial issues are included as well. [Serbo-Croat] U toku 1980. godine rad OOUR-a Nuklearni reaktor RA odvijao se u dva smera: remontnim radovima i utvrdjivanju stanja postojece opreme i u pripremi i ugradnji potrebne dodatne opreme i kompletiranju neophodne dokumentacije prema novim zakonskim propisima. Priprema postojece opreme za rad je u potpunosti izvrsena, dok se projekti i ugradnja dodatne opreme (prema zakonskim obavezama) ne odvija potrebnom brzinom zbog raznih objektivnih razloga, kao nedostatak sredstava, odobrenja, uvoza. Ovaj izvestaj sadrzi poglavlje posveceno analizi teskoca u radu koje su dovele do zabrane rada reaktora, i teskoca u realizovanju plana rada u 1980. godini, ako i podatke o finansiranju projekta 'pogon, odrzavanje i eksploatacija reaktora RA'.

  5. RA research nuclear reactor operation in forced regime, Annex 5; Prilog 5 - Rad istrazivackog nuklearnog reaktora RA u forsiranom rezimu, Prvo saopstenje

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-12-15

    In order to increase the flux and experimental potentials of the RA reactor, properties of the reactor operating in the forced regime have been inspected four times, twice with the spent fuel (core C), and twice with partly fresh fuel (cores E and F). Forced regime means power higher than nominal 6.5 MW. From the analyses of technology parameters during operation in the forced regime at power levels of 7 and 11 MW, state and behaviour of the components, efficiency of the biological protection and other parameters it was concluded that the reactor operation is possible at power levels of 10 MW during a whole year, and under certain conditions even longer operation at power levels up to 15 MW. This paper examines the reactor operation conditions in the forced regime and gives conclusions related to real increase of the experimental possibilities, isotope production and economic factors. Radi povecanja fluksa i eksperimentalnih mogucnosti reaktora RA, cetiri puta su proverene osobine reaktora u forsiranom rezimu, tj. na snagama vecim od nominalne (6,5 MW) i to dva puta sa istrosenim gorivom (jezgro C) i dva puta sa delimicno svezim (jezgra E i F). Iz analize tehnoloskih parametara u toku eksperimentalno rada reaktora u forsiranom rezimu na snagama od 7 do 11 MW, stanja i ponasanja opreme, efikasnosti bioloske zastite i ostalih parametara, zakljucuje se da je moguc permanentan rad reaktora tokom cele godine na snagama do 10 MW, a pod izvesnim uslovima i duzi rad na snagama do 15 MW. U radu su diskutovani uslovi rada reaktora u forsiranom rezimu i donose se zakljucci o realnom povecanju eksperimentalnih mogucnosti, proizvodnje radioizotopa i o ekonomskim faktorima (author)

  6. Argentina: Disposal aspects of RA-1 research reactor decommissioning waste

    Energy Technology Data Exchange (ETDEWEB)

    Harriague, S; Barberis, C; Cinat, E; Grizutti, C; Scolari, H [Comision Nacional de Energia Atomica, Buenos Aires (Argentina)

    2007-12-15

    The objective of the project is to analyze disposal aspects of waste from total dismantling of Argentinean research reactors, starting with the oldest one, 48 years old RA-1. In order to estimate decommissioning waste, data was collected from files, area monitoring, measurements, sampling to measure activity and composition, operational history and tracing of operational incidents. Measurements were complemented with neutron activation calculations. Decommissioning waste for RA-1 is estimated to be 71.5 metric tons, most of it concrete (57 tons), the rest being steels, lead and reflector graphite (4.8 tons). Due to their low specific activities, no disposal problems are foreseen in the case of metals and concrete. Disposal of aluminium, steel, lead and concrete is analyzed. On the contrary, as the country has no experience in managing graphite radioactive waste, work was concentrated on that material. Stored (Wigner) energy may exist in RA-1 graphite reflectors irradiated at room temperature. Evaluation of stored energy by calorimetric methods is proposed, and its annealing by inductive heating; HEPA filters should be used to deal with gaseous activity emissions, mainly Cl-36 and C-14. Galvanic corrosion, dust explosion, ignition and oxidation can be addressed and should not become disposal problems. Care must be taken with graphite dust generation and disposal, due to wetting and flotation problems. Lessons learned from the project are presented, and the benefits of sharing international experience are stressed. (author)

  7. Safety analysis of the present status of the research reactor 'RA' at 'Vinca' Institute

    International Nuclear Information System (INIS)

    Jovic, V.; Jovic, L.; Zivotic, Z.; Milovanovic, Dj.

    1995-01-01

    Safety analysis of the nuclear facility which has been out of work for a long time and whose future is not defined at the present moment, can not be connected to the usual, normatively regulated system analysis procedure in both operational and accidental regimes. Therefore, the safety analysis of the present status of the present status of the reactor RA is related to system and components analysis which, in present conditions maintain their nuclear functions operational. In the first place, it refers to components and equipment in which radioactive radiation generation still exists and to installations and equipment maintaining radiation level below permitted limit. in the context of the analysis the following areas are being covered: present status characteristics, accidental events while operating period from 1959. to 1984., nuclear fuels and radioactive waste inventory, basic characteristics and status of safety-related systems and equipment, radiation protection, potential accident analysis at present status of the reactor RA, potential accidental situations due to natural events (earthquakes, water flood) or man-induced events and security. 8 refs

  8. TU electric reactor model verification

    International Nuclear Information System (INIS)

    Willingham, C.E.; Killgore, M.R.

    1989-01-01

    Power reactor benchmark calculations using the code package CASMO-3/SIMULATE-3 have been performed for six cycles of Prairie Island Unit 1. The reload fuel designs for the selected cycles include gadolinia as a burnable absorber, natural uranium axial blankets, and increased water-to-fuel ratio. The calculated results for both low-power physics tests (boron end points, control rod worths, and isothermal temperature coefficients) and full-power operation (power distributions and boron letdown) are compared to measured plant data. These comparisons show that the TU Electric reactor physics models accurately predict important physics parameters for power reactors

  9. Influence of boron reduction strategies on PWR accident management flexibility

    International Nuclear Information System (INIS)

    Papukchiev, Angel Aleksandrov; Liu, Yubo; Schaefer, Anselm

    2007-01-01

    In conventional pressurized water reactor (PWR) designs, soluble boron is used for reactivity control over core fuel cycle. Design changes to reduce boron concentration in the reactor coolant are of general interest regarding three aspects - improved reactivity feedback properties, lower impact of boron dilution scenarios on PWR safety and eventually more flexible accident management procedures. In order to assess the potential advantages through the introduction of boron reduction strategies in current PWRs, two low boron core configurations based on fuel with increased utilization of gadolinium and erbium burnable absorbers have been developed. The new PWR designs permit to reduce the natural boron concentration in reactor coolant at begin of cycle to 518 ppm and 805 ppm. For the assessment of the potential safety advantages of these cores a hypothetical beyond design basis accident has been simulated with the system code ATHLET. The analyses showed improved inherent safety and increased accident management flexibility of the low boron cores in comparison with the standard PWR. (author)

  10. Dry storage of MTR spent fuel from the Argentine radioisotope production reactor RA-3; Proyecto de compactado y reubicacion de los elementos combustibles quemados del RA-3 en el deposito de combustibles MTR del Centro Atomico Ezeiza

    Energy Technology Data Exchange (ETDEWEB)

    Di Marco, A; Gillaume, E J; Ruggirello, G; Zaweruchi, A [Comision Nacional de Energia Atomica, San Martin (Argentina). Unidad de Actividad Combustibles Nucleares

    1997-12-31

    The nuclear fuel elements of the RA-3 reactor consist in 19 rectangular fuel plates held in position by two lateral structural plates. The whole assembly is coupled to the lower nozzles that fits in the reactor core grid. The inner plates are 1.5 mm thick, 70.5 mm wide and 655 mm long and the outer plates are 100 mm longer. The fuel plates are formed by a core of an AI-U alloy co-laminated between two plates of Al. Enrichment is 90% {sup 235}U. After being extracted from the reactor, the fuel elements have been let to cool down in the reactor storage pool and finally moved to the storage facility. This facility is a grid of vertical underground channels connected by a piping system. The system is filled with processed and controlled water. At the present the storage capacity of the facility is near to be depleted and some indications of deterioration of the fuel elements has been detected. Due to the present status of the facility and the spent fuel stored there, a decision has been taken to proceed to modify the present underwater storage to dry storage. The project consist in: a) Decontamination and conditioning of the storage channels to prepare them for dry storage. b) Disassembly of the fuel elements in hot cells in order to can only the active fuel plates in an adequate tight canister. c) The remnant structural pieces will be treated as low level waste. (author). 10 figs.

  11. Analysis of boron dilution in a four-loop PWR

    International Nuclear Information System (INIS)

    Sun, J.G.; Sha, W.T.

    1995-03-01

    Thermal mixing and boron dilution in a pressurized water reactor were analyzed with COMMIX codes. The reactor system was the four-loop Zion reactor. Two boron dilution scenarios were analyzed. In the first scenario, the plant is in cold shutdown and the reactor coolant system has just been filled after maintenance on the steam generators. To flush the air out of the steam generator tubes, a reactor coolant pump (RCP) is started, with the water in the pump suction line devoid of boron and at the same temperature as the coolant in the system. In the second scenario, the plant is at hot standby and the reactor coolant system has been heated to operating temperature after a long outage. It is assumed that an RCP is started, with the pump suction line filled with cold unborated water, forcing a slug of diluted coolant down the downcomer and subsequently through the reactor core. The subsequent transient thermal mixing and boron dilution that would occur in the reactor system is simulated for these two scenarios. The reactivity insertion rate and the total reactivity are evaluated and a sensitivity study is performed to assess the accuracy of the numerical modeling of the geometry of the reactor coolant system

  12. Report on participation of the operational dosimetry division in refurbishment of the RA reactor, Task 3.08/04-13

    International Nuclear Information System (INIS)

    Ninkovic, M.

    1963-01-01

    During the refurbishment of the RA reactor, from January to June 1963 the division of operational division had a very important role and comprehensive tasks. To enable safety of the staff it was necessary to provide protection clothes, personnel dosemeters; permanent monitoring of radiation doses; strict control of the procedures for completing the planned maintenance and repair operations to avoid contamination of the personnel and working space. The refurbishment activities described in this report are: removal of fuel from the core; refurbishment of the heavy water system; decontamination of the distillation equipment; repair of the gas system

  13. Absolute measurements of the fast neutron flux in the reactor RA

    Energy Technology Data Exchange (ETDEWEB)

    Berovic, N; Boreli, F; Dragin, R [Institute of Nuclear Sciences Boris Kidric, Department of physics, Vinca, Beograd (Serbia and Montenegro)

    1961-10-15

    The absolute neutron flux in the vertical VK-5 hole of the reactor RA was determined by using the {sup 27}Al (n, alpha) {sup 24}Na reaction, and by counting the {sup 24}Na - 2.5 MeV gamma line photopeak activity. A method for the determination of {sigma}{sub eff} as a mean value between the two large limiting cases of neutron spectra is used. The flux at the power level of 5 MW was found to be (2.5{+-}0.9){center_dot}10{sup 12}n/cm{sup 2}sec (author)

  14. Continuous Monitoring of GAMMA Radiation Field in the Reactor RA Building

    International Nuclear Information System (INIS)

    Stalevski, T.

    2008-01-01

    This paper presents the system for continuos monitoring of gamma doze rate in the reactor RA building. Industrial (PC compatible) computer acquires analog signals from eight ionization chambers and eight analog signals from three BPH devices. Digital output interface is used for testing ionization chambers and BPH devices. Computer program for data analyzes and presentation is written in graphical programming language LabVIEW and enables monitoring of measured data in real time. Measured data can be monitored over local computer network, Internet and mobile devices using standard web browsers. (author)

  15. Experience about performance of experimental facility VISA-2 for materials irradiation by the fast neutron flux at the RA reactor in Vinca; Iskustvo u radu eksperimentalnih uredjaja VISA-2 za ozracivanje materijala u fluksu brzih neutron na reaktoru RA u Vinci

    Energy Technology Data Exchange (ETDEWEB)

    Pavicevic, M [Institut za nuklearne nauke Boris Kidric, Vinca, Beograd (Yugoslavia)

    1964-07-01

    VISA-2 is an experimental device placed in the core of the RA reactor cooled by heavy water. The objective of constructing this device was irradiation of non-fissile samples of reactor materials in order to test radiation damage. Since the first irradiation program performed in 1962 a number of long-term irradiations were done successfully. This proved the device to be useful and showed new possibilities for RA reactor application. The irradiation programs were performed in cooperation with CEA- Saclay.

  16. Radiation protection at the RA Reactor in 1989, Part -2, Decontamination, collection of treatment of fluid and solid radioactive waste, Annex 3

    International Nuclear Information System (INIS)

    Mandic, M.; Vukovic, Z.; Plecas, I.; Knezevic, Lj.; Lazic, S.; Bacic, S.

    1989-01-01

    Certain amount of solid waste results from RA reactor operation, the mean quantity of which depends on the duration of reactor operation and related activities. During repair, when reactor is not operated as well under accidental conditions, the quantity of waste is higher, dependent on the type of repair and comprehensiveness of decontamination of the working surface, contaminated tools and components. The waste is sorted and packed on the spot where they appeared according to the existing regulations and principles of radiation protection with aim to minimize unnecessary exposure of the radiation protection personnel who deals with control, transport, radioactive waste treatment and decontamination. During exceptional operations (decontamination, repair, bigger volume of contaminated material, etc.) professional staff of the Radiation protection department gives recommendations and helps in planning the actions related to repair, sorting and packaging of radioactive waste in special containers, identification of the contaminants, etc. [sr

  17. Safety analysis of RA reactor operation, I-III, Part III - Environmental effect of the maximum credible accident

    International Nuclear Information System (INIS)

    Raisic, N.

    1963-02-01

    Maximum credible accident at the RA reactor would consider release of fission products into the environment. This would result from fuel elements failure or meltdown due to loss of coolant. The analysis presented in this report assumes that the reactor was operating at nominal power at the moment of maximum possible accident. The report includes calculations of fission products activity at the moment of accident, total activity release during the accident, concentration of radioactive material in the air in the reactor neighbourhood, and the analysis of accident environmental effects

  18. Investigation on the neutron beam characteristics for boron neutron capture therapy with 3D and 2D transport calculations

    International Nuclear Information System (INIS)

    Kodeli, I.; Diop, C.M.; Nimal, J.C.

    1994-01-01

    In the framework of future Boron Neutron Capture Therapy (BNCT) experiments, where cells and animals irradiations are planned at the research reactor of Strasbourg University, the feasibility to obtain a suitable epithermal neutron beam is investigated. The neutron fluence and spectra calculations in the reactor are performed using the 3D Monte Carlo code TRIPOLI-3 and the 2D SN code TWODANT. The preliminary analysis of Al 2 O 3 and Al-Al 2 O 3 filters configurations are carried out in an attempt to optimize the flux characteristics in the beam tube facility. 7 figs., 7 refs

  19. Operation and maintenance of the RA reactor in 1965; Pogon i odrzavanje reaktora RA. Izvestaj o radu u 1965. godini

    Energy Technology Data Exchange (ETDEWEB)

    Milosevic, D [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

    1966-01-15

    It has been planned for 1965 that the RA reactor would be operated each month for 20 days at nominal power of 6.5 MW, at lower power for 5 days, meaning production of 27 400 MWh. The plan was fulfilled since reactor produced 28809 MWh, i.e. 5% more than planned. Reactor was used for irradiation in the vertical experimental channels according to the demand of 1264 users from the Institute and 191 external users. Two groups of experiments done: at nominal power simultaneously with isotope production and experiments which demanded particular power levels and temperatures. Three fuel exchanges were done during this year, meaning that 40 fuel channels were changed in total. Vertical experimental channels VEK-1 and VEK-9 having diameter 100 mm were changed by channels having diameter 50 mm and shortened by 435 mm. Channel VEK-5 with diameter 110 mm was changed shortened by 430 mm. This enabled better fuel economy, the burnup was increased from 4500 MWd/t to 5000 MWd/t. This report contains the action plan for 1966.

  20. Operation and maintenance of the RA Reactor in 1985, Part 1, Annex D - Report of the Mechanics Service

    International Nuclear Information System (INIS)

    Sulem, B.

    1985-01-01

    Service for mechanical components at the RA reactor includes: control and maintenance of utility components, mechanical workshop, hot cells and storage. Control and maintenance of main components covers: reactor core, heavy water system, technical water system, gas system. This service is responsible for the following auxiliary systems: transportation units; spent fuel storage pool; special ventilation system; personal protection appliances; hot cells. Maintenance of the reactor building, ventilation, heating, water supply, sewage, fire protection devices, gas and compressed air systems are included [sr

  1. Work related to increasing the exploitation and experimental possibilities of the RA reactor, 05. Independent CO2 loop for cooling the samples irradiated in the RA vertical experimental channels (I-IV), Part II, IZ-240-0379-1963, Vol. II Head of the low temperature RA reactor coolant loop

    International Nuclear Information System (INIS)

    Pavicevic, M.

    1963-07-01

    The objective of the project was to design the head of the CO 2 coolant loop for cooling the materials during irradiation in the RA reactor. Six heads of coolant loops will be placed in the RA reactor, two in the region of heavy water in the experimental channels VEK-6 and four in the graphite reflector in the channels VEK-G. maximum generated heat in the heads of the coolant loop is 10500 kcal/h and minimum generated heat is 1500 kcal/h. The loops are cooled by CO 2 gas, coolant flow is 420 kg/h, and the pressure is 4.5 atu. There is a need to design and construct the secondary coolant loop for the low temperature coolant loop. This volume includes technical specifications of the secondary CO 2 loop with instructions for construction and testing; needed calculations; specification of materials; cost estimation for materials, equipment and construction; and graphical documentation [sr

  2. Two-channel neutron boron meter

    International Nuclear Information System (INIS)

    Chen Yongqing; Yin Guowei; Chai Songshan; Deng Zhaoping; Zhou Bin

    1993-09-01

    The two-channel neutron boron meter is a continuous on-line measuring device to measure boron concentration of primary cooling liquid of reactors. The neutron-leakage-compensation method is taken in the measuring mechanism. In the primary measuring configuration, the mini-boron-water annulus and two-channel and central calibration loop are adopted. The calibration ring and constant-temperature of boron-water can be remotely controlled by secondary instruments. With the microcomputer data processing system the boron concentration is automatically measured and calibrated in on-line mode. The meter has many advantages such as high accuracy, fast response, multi-applications, high reliability and convenience

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

    International Nuclear Information System (INIS)

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

    2004-01-01

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

  4. Collaborative Physical and Biological Dosimetry Studies for Neutron Capture Therapy at the RA-1 Research Reactor Facility

    Energy Technology Data Exchange (ETDEWEB)

    David W. Nigg; Amanda E. Schwint; John K. Hartwell; Elisa M. Heber; Veronica Trivillin; Jorge Castillo; Luis Wentzeis; Patrick Sloan; Charles A. Wemple

    2004-10-01

    Initial physical dosimetry measurements have been completed using activation spectrometry and thermoluminiscent dosimeters to characterize the BNCT irradiation facility developed at the RA-1 research reactor operated by the Argentine National Atomic Energy Commission in Buenos Aires. Some biological scoping irradiations have also been completed using a small-animal (hamster) oral mucosa tumor model. Results indicate that the RA-1 neutron source produces useful dose rates but that some improvements in the initial configuration will be needed to optimize the spectrum for thermal-neutron BNCT research applications.

  5. Collaborative Physical and Biological Dosimetry Studies for Neutron Capture Therapy at the RA-1 Research Reactor Facility

    Energy Technology Data Exchange (ETDEWEB)

    Nigg, D.W.; Schwint, A.E.; Hartwell, J.K.; Heber, E.M.; Trivillin, V.; Castillo, J.; Wentzeis, L.; Sloan, P.; Wemple, C.A.

    2004-10-04

    Initial physical dosimetry measurements have been completed using activation spectrometry and thermoluminiscent dosimeters to characterize the BNCT irradiation facility developed at the RA-1 research reactor operated by the Argentine National Atomic Energy Commission in Buenos Aires. Some biological scoping irradiations have also been completed using a small-animal (hamster) oral mucosa tumor model. Results indicate that the RA-1 neutron source produces useful dose rates but that some improvements in the initial configuration will be needed to optimize the spectrum for thermal-neutron BNCT research applications.

  6. Peak power factor determination of the RA-6 Argentinean Research Reactor using measurement-calculations correlations

    International Nuclear Information System (INIS)

    Sanchez, F. A.; Blaumann, H.; Lopasso, E.; Longhino, J

    2009-01-01

    The maximum power of a reactor is limited by the power peaking factor. During the design stage it is calculated with neutronic calculation codes. This is not enough for ensuring its value due to modelling approximations. For the RA-6s low enrichment new core a calculus-measurement correlation method have been applied. Position and magnitude of the maximum power density estimated by calculus are used by this method. For this work 249 cooper-gold alloy (1.55% Au) wires have been distributed along the core using 19 aluminium blades. Their positions have been selected using information given by a 5 groups PUMA reactor model. Wire s activity have been measured with a HPGe detector. Gold activity have been used only for verifying the calculated core spectrum. The measured power peaking factor was 2.48±0.3 (3σ), 15% above the calculated value. About 97% of measured points had less than 20% calculation-measurement difference and about 80% had less than 10%. The power peaking factor determined by this method consolidates also the calculations models. [es

  7. RA Reactor operation and maintenance (I-IX), part VIII, Task 3.08/05, Decontamination of the reactor; Pogon i odrzavanje reaktora (I-IX), VIII Deo, Zadatak 3.08/05 Dekontaminacija reaktora

    Energy Technology Data Exchange (ETDEWEB)

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

    1963-12-15

    Permanent increase of radiation in the heavy water system was noticed during first three year of the RA reactor operation, even when the reactor was shutdown. It was found that there was no failure of the fuel element cladding. Radioactive cobalt was found in the heavy water which was rather strange. During repair of the heavy water system, it has been found that stellite was used for coating the heavy water pumps. Since stellite is a cobalt alloy, this could have been the source of radioactive cobalt in the heavy water. The stellite coating was damaged due to friction and particle of cobalt appeared in the coolant, they were activated since they were in the core. decontamination of the heavy water and the heavy water coolant loop was a must . Beside the detailed report on the contamination and decontamination of the heavy water system this volume includes 14 annexes describing the investigation of the event and the whole procedure of decontamination.

  8. Preparation of mandatory documentation before the start up of the RA-0 'zero power' nuclear reactor at Cordoba National University

    International Nuclear Information System (INIS)

    Martin, H.R.; Keil, W.M.; Pezzi, N.

    1991-01-01

    Before the start up of the RA-0 'zero power' nuclear reactor installed at Cordoba National University, it was necessary to send to the Regulatory Authority the mandatory documentation which is required in the licensing process. With the previous papers existing for the operation in the first years of the '70, a work program for the future operational training personnel was elaborated. Based on the Authority's applicable rules and the recommendations and with particular criteria originated in the working university conditions, the SAFETY report of RA-0 nuclear reactor was prepared. This paper describes the principal contents, items and documents involved in the safety report. (Author) [es

  9. Accuracy Improvement of Boron Meter Adopting New Fitting Function and Multi-Detector

    Directory of Open Access Journals (Sweden)

    Chidong Kong

    2016-12-01

    Full Text Available This paper introduces a boron meter with improved accuracy compared with other commercially available boron meters. Its design includes a new fitting function and a multi-detector. In pressurized water reactors (PWRs in Korea, many boron meters have been used to continuously monitor boron concentration in reactor coolant. However, it is difficult to use the boron meters in practice because the measurement uncertainty is high. For this reason, there has been a strong demand for improvement in their accuracy. In this work, a boron meter evaluation model was developed, and two approaches were considered to improve the boron meter accuracy: the first approach uses a new fitting function and the second approach uses a multi-detector. With the new fitting function, the boron concentration error was decreased from 3.30 ppm to 0.73 ppm. With the multi-detector, the count signals were contaminated with noise such as field measurement data, and analyses were repeated 1,000 times to obtain average and standard deviations of the boron concentration errors. Finally, using the new fitting formulation and multi-detector together, the average error was decreased from 5.95 ppm to 1.83 ppm and its standard deviation was decreased from 0.64 ppm to 0.26 ppm. This result represents a great improvement of the boron meter accuracy.

  10. Accuracy improvement of boron meter adopting new fitting function and multi-detector

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Chidong; Lee, Hyun Suk; Tak, Tae Woo; Lee, Deok Jung [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of); KIm, Si Hwan; Lyou, Seok Jean [Users Incorporated Company, Hansin S-MECA, Daejeon (Korea, Republic of)

    2016-12-15

    This paper introduces a boron meter with improved accuracy compared with other commercially available boron meters. Its design includes a new fitting function and a multi-detector. In pressurized water reactors (PWRs) in Korea, many boron meters have been used to continuously monitor boron concentration in reactor coolant. However, it is difficult to use the boron meters in practice because the measurement uncertainty is high. For this reason, there has been a strong demand for improvement in their accuracy. In this work, a boron meter evaluation model was developed, and two approaches were considered to improve the boron meter accuracy: the first approach uses a new fitting function and the second approach uses a multi-detector. With the new fitting function, the boron concentration error was decreased from 3.30 ppm to 0.73 ppm. With the multi-detector, the count signals were contaminated with noise such as field measurement data, and analyses were repeated 1,000 times to obtain average and standard deviations of the boron concentration errors. Finally, using the new fitting formulation and multi-detector together, the average error was decreased from 5.95 ppm to 1.83 ppm and its standard deviation was decreased from 0.64 ppm to 0.26 ppm. This result represents a great improvement of the boron meter accuracy.

  11. The incorporation of boron in fissile transport packages for the transport and interim storage of irradiated light water reactor fuels

    International Nuclear Information System (INIS)

    Hunter, I.J.

    1998-01-01

    Boron is widely used in the nuclear industry for capturing neutrons and it is particularly useful in the criticality control of packages for the transport and interim storage of irradiated light water reactor fuels. Such fuels are typically located in an internal frame of stainless steel or aluminium, referred to as a basket, which locates the fuel assemblies in channels. Transnucleaire has designed and supplied more than 100 baskets of varying types during the past 30 years. Boron has been incorporated in many forms. Early designs of baskets used boron in specific zones to contribute to the control of criticality. Later developments in new materials dispersed boron throughout the basket and gave designers more options for the basic forms which make up the channels. New basket concepts have been developed by Transnucleaire to meet the changing market needs for transport and interim storage and boron continues to play an important role as an efficient thermal neutron absorber. (author)

  12. Data concerning operation and application of RA reactor in 1975, Annex 1; Prilog 1 - Podaci o radu i iskoriscenosti reaktora RA u 1975. godini

    Energy Technology Data Exchange (ETDEWEB)

    Stanic, A [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1976-01-15

    RA reactor was operating according to the plan for 1975 adopted in December of the previous year. It was planned for reactor to be operated at nominal power first 10-20 days each month, three following days were reserved for different power levels according to the users' demand. Four fuel exchanges were planned and fulfilled with minor delay. Data concerning planned and real operation, as well as delays from the plan and shorter interruptions are presented in tables of this Annex. It is shown that all the delays and interruptions which amounted to 104 hours were compensated. [Serbo-Croat] Reaktor RA je radio prema planu rada za 1975. godinu, nacinjenom u decembru prethodne godine. Planirano je da reaktor radi neprekidno prvih 10-20 dana u mesecu na nominalnoj snazi, tri sledeca dana je rezervisano za rad na drugim snagama zavisno od potreba korisnuka. Planirane su i 4 izmene goriva. Podaci o planiranom i ostvarenom radu kao i odstupanjima od plana i kracim prekidima u radu reaktora dati su u tabelama ovog priloga. Vidi se da su sva odstupanja i prekidi u ukupnom trajanju od 104 sata u celini nadoknadjeni.

  13. RA Research reactor Annual report 1982 - Part 1, Operation, maintenance and utilization of the RA reactor

    International Nuclear Information System (INIS)

    Sotic, O.; Martinc, R.; Kozomara-Maic, S.; Cupac, S.; Radivojevic, J.; Stamenkovic, D.; Skoric, M.; Miokovic, J.

    1982-12-01

    Reactor test operation started in September 1981 at 2 MW power with 80% enriched fuel continued during 1982 according to the previous plan. The initial reactor core was made of 44 fuel channel each containing 10 fuel slugs. The first half of 1982 was used for the needed measurements and analysis of operating parameters and functioning of reactor systems and equipment under operating conditions. Program concerned with the testing operation at higher power levels was started in the second half of this year. It was found that the inherent excess reactivity and control rod worths ensure safe operation according to the IAEA safety standards. Excess reactivity is high enough to enable higher power level of 4.7 MW during 4 monthly cycles each lasting 15-20 days. Favourable conditions for cooling exist for the initial core configuration. Effects of poisoning at startup on the reactivity and power density distribution were measured as well as initial spatial distribution of the neutron flux which was 3,9 10 13 cm -2 s -1 at 2 MW power. Modification of the calibration coefficient in the system for automated power level control was determined. All the results show that all the safety criteria and limitations concerned with fuel utilization are fulfilled if reactor power would be 4.7 MW. Additional testing operation at 3, 4, and 4.7 MW power levels will be needed after obtaining the licence for operating at nominal power. Transition from the initial core with 44 fuel channels to the equilibrium lattice configuration with 72 fuel channels each containing 10 fuel slugs, would be done gradually. Reactor was not operated in September because of the secondary coolant pipes were exchanged between Danube and the horizontal sedimentary. Control and maintenance of the reactor equipment was done regularly and efficiently dependent on the availability of the spare parts. Difficulties in maintenance of the reactor instrumentation were caused by unavailability of the outdated spare parts

  14. RA-3 reactor core with uranium silicide fuel elements P-07 type

    International Nuclear Information System (INIS)

    Abbate, Maximo J.; Sbaffoni, Maria M.

    2003-01-01

    Following the studies on the utilization of fuel elements (FE) containing uranium silicide, core of the RA-3 was analyzed with several calculation models. At first, the present situation, i.e. the core charged with normal FE (U 3 O 8 ), has been analyzed to validate the simulation methodology comparing with experimental results and to establish reference data to 5 and 10 MW able to be compared with future new situations. Also, CITVAP's nuclear data libraries to be used in irradiation experiment planning were completed. The results were satisfactory and were applied to the study of the core containing P-07 FE [U 3 Si 2 ], in face of a future core change. Comparing with the performance of the U 3 O 8 FE, the silicides ones show the following advantages: - average burnup: 45 % greater; -extraction burnup increase 12 %; and, -the residence time [in full power days] could be a 117 % greater. (author)

  15. Actions needed for RA reactor exploitation - I-IV, Part II, Design project VI-SA 1, Experimental loop for testing the EL-4 reactor fuel elements in the central vertical experimental channel of the RA reactor in Vinca; Radovi za potrebe eksploatacije reaktora RA - I-IV, II Deo, Predprojekat VI-SA 1, Petlja za ispitivanje gorivnih elemenata reaktora EL-4 u centralnom vertikalnom eksperimentalnom kanalu reaktora RA u Vinci

    Energy Technology Data Exchange (ETDEWEB)

    Novakovic, M [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1961-12-15

    The objective of installing the VISA-1 loop was testing the fuel elements of the EL-4 reactor. The fuel elements planned for testing are natural UO{sub 2} with beryllium cladding, cooled by CO{sub 2} under nominal pressure of 60 at and temperature 600 deg C. central vertical experimental channel of the RA reactor was chosen for installing a test loop cooled by CO{sub 2}. This report contains the detailed design project of the testing loop with the control system and safety analysis of the planned experiment.

  16. Ra reactor operation plan for 1976 - Annex 6

    International Nuclear Information System (INIS)

    Martinc, R.

    1976-01-01

    Contrary to previous years the RA reactor operation plan for 1976 is conditioned by more uncertainties than ever for the following reasons. It is planned for February to repair the components in order to eliminate the consequences of leaking from the vertical experimental channel VK-4 which happened in december 1975. Apart from this, measurements related to transfer of the core to highly enriched fuel under minimum power are foreseen to be performed in February. In April, it would be indispensable to locate the point of He gas leaking and its prevention. Core transfer to highly enriched fuel is planned for April for testing of the fuel elements under operating conditions and step by step increase of the power density up to the nominal power. Complete plan for core transfer would be available by the end of February 1976. It is planned to make-up for the mentioned delays from May-December 1976 [sr

  17. Calculated activities of some isotopes in the RA reactor highly enriched fuel significant for possible environmental contamination - Operational report; Radni izvestaj - Proracun aktivnosti nekih izotopa u visokoobogacenom uranskom gorivu reaktora RA, znacajnih sa gledista moguce kontaminacije okoline

    Energy Technology Data Exchange (ETDEWEB)

    Bulovic, V; Martinc, R; Cupac, S [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1976-12-15

    This report contains calculation basis and obtained results of activities for three groups of isotopes in the RA reactor 80% enriched fuel element. The following isotopes are included: 1) {sup 85m}Kr, {sup 87}Kr, {sup 88}Kr, {sup 131}J, {sup 132}J, {sup 133}J, {sup 134}J, {sup 135}J, {sup 133}Xe, {sup 138}Xe i {sup 138}Cs, 2) {sup 89}Sr, {sup 90}Sr, {sup 91}Sr, {sup 92}Sr, {sup 95}Zr, {sup 97}Zr, {sup 103}Ru, {sup 105}Ru, {sup 106}Ru, {sup 129m}Te, {sup 134}Cs, {sup 137}Cs, {sup 140}Ba, {sup 144}Ce, kao i 3) {sup 238}Pu, {sup 239}Pu i {sup 240}Pu. It was estimated that the fuel is exposed to mean neutron flux. The periodicity of reactor operation is taken into account. Calculation results are given dependent on the time of exposure. These results are to be used as source data for Ra reactor safety analyses. [Serbo-Croat] Izlozene su osnove i prikazani su rezultati izvedenog proracuna aktivnosti tri grupe izotopa u gorivnom elementu reaktora RA sa 80% obogacenim uranom - 235. Obuhvaceni su: 1) {sup 85m}Kr, {sup 87}Kr, {sup 88}Kr, {sup 131}J, {sup 132}J, {sup 133}J, {sup 134}J, {sup 135}J, {sup 133}Xe, {sup 138}Xe i {sup 138}Cs, zatim, 2) {sup 89}Sr, {sup 90}Sr, {sup 91}Sr, {sup 92}Sr, {sup 95}Zr, {sup 97}Zr, {sup 103}Ru, {sup 105}Ru, {sup 106}Ru, {sup 129m}Te, {sup 134}Cs, {sup 137}Cs, {sup 140}Ba, {sup 144}Ce, kao i 3) {sup 238}Pu, {sup 239}Pu i {sup 240}Pu. Pretpostavljeno je da se gorivo ozracuje na srednjem fluksu neutrona, a periodicnost rada reaktora je uvazavana. Rezultati proracuna, dati u numerickom obliku, sistematizovani su kao funkcija toka vremena ozracivanja goriva. Ovi rezultati bice korisceni kao izvorni podaci kod izrade sigurnosnih analiza za reaktor RA (author)

  18. Development of a process to recover boron carbide from nuclear reactor absorber rods

    International Nuclear Information System (INIS)

    Roth, C.; Lehnert, T.

    1991-01-01

    Boron carbide enriched with 10 B is used as a control rod in reactor engineering. At present spent rods are disposed of, although major amounts of 10 B are still 'unused'. The objective was to recover 10 B from the control rods by an energy and cost saving method in order to use it for making new control rods, thus saving raw materials and minimizing the radioactive waste volume. For this purpose, the well-known pyrohydrolysis process was taken and analysed for possible improvements. By mixing boron carbide with CO 2 as an oxidation-supporting agent, a lowering of the reaction temperature by 300deg C, and an increase in the oxidation speed by 350% were achieved. Since C0 2 is not consumed and can be circulated, the method for reprocessing spent control rods presented in this paper is both an economy-priced an energy-saving one. (orig.) With 98 refs., 9 tabs., 14 figs [de

  19. Neutron spectrometry in mixed fields: characterisation of the Ra-1- reactor workplace

    International Nuclear Information System (INIS)

    Gregori, B.; Carelli, J.; Cruzate, J.; Papadopulos, S.

    2006-01-01

    The characterisation of the neutron spectrum of a workplace is an essential dosimetric tool for improving the assessment of the personal equivalent dose of the workers. In addition, if the operational conditions of the facility are well defined, the set of field spectra obtained may be used as a reference for comparing the performance of different type of neutron detectors. Recently, using a neutron spectrometric system based on a set of moderated spheres with 3 He detector, the characterisation of the neutron spectra in workplaces of the Argentine Reactor No. 1 (R.A. -1) has been carried out. The spectrometric system consists of 12 spheres made of the high density polyethylene d mean δ =0.95 g cm 3 , with diameters between 3'' and 12'' and a proportional counter of 3 He, 4 atm of nominal pressure, Centronic trade mark, located in the centre of the spheres. The neutron response matrix was calculated using the M.C.N.P. -I.V.B. code and E.N.D.F./B-VI library in the energy range between thermal neutron and 100 MeV. The neutron spectrum was unfolded using the M.A.X.E.D. unfolding code. The validation of the spectrometric system was performed at Cea-Cadarache (France) with of 252 Cf, Am Be, and 252 Cf + D 2 O sources. Therefore, in this work, the spectral fluence of the field in the selected points of the facility (R.A.-1) has been presented and the ambient dose equivalent, H *(10), and the personal dose equivalent, Hp(10), have been derived from the neutron fluence, applying ICRP-74 recommended fluence to dose conversion factors. The quantities evaluated have uncertainties less than 15%, which is considered good enough for radiation protection requirements. (authors)

  20. Determination of the neutron spectrum at different locations in the Argentine RA-1 Reactor; Determinacion del espectro neutronico en distintas posiciones del reactor RA-1

    Energy Technology Data Exchange (ETDEWEB)

    Lerner, A M; Madariaga, M R [Autoridad Regulatoria Nuclear, Buenos Aires (Argentina)

    1999-12-31

    Full text: It is well known that the RA-1 reactor is used to irradiate different types of materials with neutrons. The Radio dosimetry Group (which belongs to the Nuclear Regulatory Authority) uses its fast column for the design, calibration and set up of criticality dosimeters as well as for a quick assessment of the dose to workers in case of an accident. With such purpose, Au(1), Au under Cd and In(2) foils were irradiated to estimate absolute thermal, epithermal and fast neutron fluxes at the irradiation location. The accuracy of this estimation is higher when the response to the present neutron spectrum of the different materials constituting the detectors is better known. This, in turn, requires the previous knowledge of such spectrum (a detailed energy dependence of neutron flux) at the analysed location. In this work a neutronic calculation is presented at the fast irradiation location. The whole calculation was carried out following two different methodologies, and considering a power of 40 kW. The reactor and its surroundings were represented by a simplified one-dimensional model, as a concentric cylindrical set of regions. Figures are drawn representing fast and thermal fluxes (with the cut at 0.4 eV) as a function of the distance to the core centre. The neutron flux (in n/cm{sup 2}sec.eV) as a function of energy is also shown at the fast irradiation location. Values of flux (in n/cm{sup 2}.sec.eV) are also provided as a function of energy in other typical locations, as well as the equivalent integrated flux values (in n/cm{sup 2}.sec). ((1) According to the reaction Au{sup 197}(n,{gamma})Au{sup 198}, having a cross section of {sigma}{sub 0}=98.8b for thermal neutrons. (2) According to the reaction In{sup 115}(n,n`)In{sup 115m}, with a cross section of some 70 mb for neutrons with energies above 1.2MeV). (author) [Espanol] Texto completo: Como se sabe, el reactor RA1 se utiliza para irradiar con neutrones distintos tipos de materiales. El grupo de

  1. Activity of the Service for maintenance of mechanical equipment of the RA reactor - Report, Annex II; Prilog II - Rad sluzbe za odrzavanje masinske opreme reaktora RA u 1979. godini - Izvestaj -

    Energy Technology Data Exchange (ETDEWEB)

    Radivojevic, J [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1979-12-15

    Service for mechanical components at the RA reactor includes: control and maintenance of utility components, mechanical workshop, hot cells and storage. Control and maintenance of main components covers: reactor core, heavy water system, technical water system, gas system. This service is responsible for the following auxiliary systems: transportation units; spent fuel storage pool; special ventilation system; personal protection appliances; hot cells. Maintenance of the reactor building, ventilation, heating, water supply, sewage, fire protection devices, gas and compressed air systems are included. [Serbo-Croat] Sluzba za masinsku opremu nuklearnog reaktora RA obuhvata: kontrolu i odrzavanje masinske opreme postrojenja, masinsku radionicu, vruce komore i prirucni magacin. Kontrola i odrzavanje osnovnih sistema obuhvata centralno telo reaktora, sistem teske vode, sistem tehnicke vode, gasni sistem. Pomocni sistemi koji spadaju u delatnost ove sluzbe su: transportna oprema, bazen za odlezavanje ozracenog goriva, sistem specijalne ventilacije, licna zastitna sredstva, vruce komore. Odrzavanje zgrade reaktora, ventilacije i grejanja, vodovoda i kanalizacije, opreme za protivpozarnu zastitu, instalacije gasa i komprimovanog vazduha su takode zadatak ove Sluzbe.

  2. RA Research reactor, Annual report 1970 - Operation and maintenance; Istrazivacki nuklearni reaktor RA - Izvestaj za 1970. godinu - Pogon i odrzavanje

    Energy Technology Data Exchange (ETDEWEB)

    Milosevic, D et al. [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1970-12-15

    During 1970, the RA Reactor was operated at nominal power of 6.5 MW for 160 days, and 40 days at lower power levels. Total production mounted to 25968 MWh which is 3.87% higher than planned. The action plan was changed compared to the previous years because of sending the heavy water to France for re-concentration. Isotopic concentration of the heavy water was decreased to 99.05% and now after re-concentration it is 99.96%. Discrepancy from the action plan, in September was caused by the delay return of the heavy water for administrative and transportation difficulties. The restart of the reactor in September was postponed because the cladding of one fuel element was damaged immediately after the start-up, and the reactor had to be shutdown. In October and November reactor was in operation 28 and 25 days respectively which enabled to make up for the lost time. Reactor was used for irradiation and experiments according to the demand of 390 users, 340 from the Institute and 50 external users. This report contains detailed data about reactor power and experiments performed in 1969. It is concluded that the reactor operated successfully according to the plan. Shorter interruptions were caused only by difficulties with water supply pipes and sliding of the soil. Reactor was only twice scram shutdown because of the false signals caused by failures of the electronic control instrumentation. the period when reactor was not in operation was used for inspection of the reactor vessel internals. By using special TV cameras and telescopes, it was found that the there are no signs of corrosion on the reactor vessel, e.e. that the internals are in a very good state. Simultaneously, connection for the pipes of future emergency core cooling system were constructed. During 1970, the spent fuel was repacked from fuel channels into special aluminium casks. Four casks containing 660 fuel slugs was deposited int the storage pool No.4. There is now 18 casks with 2951 spent fuel slugs in

  3. Determination of reactor parameters in a simulated RA reactor lattice by measuring the reactivity level of heavy water in D{sub 2}O moderated RB reactor; Odredjivanje reaktorskih parametara u simuliranoj resetki reaktora RA merenjem reaktivnosti nivoa teske vode u D{sub 2}O moderiranom reaktoru RB

    Energy Technology Data Exchange (ETDEWEB)

    Takac, S M; Markovic, H D; Dimitrijevic, Z B [Institute of Nuclear Sciences Vinca, Beograd (Serbia and Montenegro)

    1974-07-01

    Direct method for experimental determination of the neutron age {tau} in the reactor lattice is not developed. Fermi theory for determining {tau} by measuring the reactivity level of the heavy water can be applied for a limited number of reactor lattices. An attempt was made to apply this approach for a complex reactor core with side and upper reflector. As expected the obtained results were not satisfactory, and {tau} was determined by Dessauer formula which gives more realistic estimation of thermalization in the reactor cell. major discrepancies are resulting from the fact that the lower reflector was neglected. But it is possible to to determine {tau} for reactor core with reflectors by additional measurements of axial distribution and other experimental data for {tau}. This is quite tedious numerical procedure. Obtained experimental data for a number of reactor parameters are compared to the initial data of the RA reactor core showing very good agreement. [Serbo-Croat] Ekspeimentalna metoda za direktno odredjivanje starosti neutrona {tau}, u resetki reaktora do danas nije razvijena. Primenjena Fermijeova teorija za odredjivanje {tau} preko merenja reaktivnosti nivoa teske vode, ocigledno se moze koristiti samo na ogranicen spektar reaktorskih resetki. U ovom radu pokusano je da se vidi primenljivost iste u slozenom - bocno i odozdo - reflektovanom jezgru reaktora. Naravno dobijeni rezultati nisu zadovoljili, sto se i moglo ocekivati, pa je {tau} odredjen preko Dessauer-ove formule, sto daje daleko blizu sliku stvarnog stanja procesa termalizacije u celiji reaktora. Ocigledno vece neslaganje primenjene teorije dolazi od zanemarivanja donjeg reflektora u jezgru reaktora. Medjutim, dopnskim merenjem aksijalne raspodele i na osnovu ostalih eksperimentalnih podataka za {tau}, moguce je odrediti eksperimentalno reflektorski koeficijent za visestruko reflektovano jezgro reaktora, sto numericki predstavlja mukotrpan i dugotrajan rad na racunaru. Dobijeni

  4. TU Electric reactor physics model verification: Power reactor benchmark

    International Nuclear Information System (INIS)

    Willingham, C.E.; Killgore, M.R.

    1988-01-01

    Power reactor benchmark calculations using the advanced code package CASMO-3/SIMULATE-3 have been performed for six cycles of Prairie Island Unit 1. The reload fuel designs for the selected cycles included gadolinia as a burnable absorber, natural uranium axial blankets and increased water-to-fuel ratio. The calculated results for both startup reactor physics tests (boron endpoints, control rod worths, and isothermal temperature coefficients) and full power depletion results were compared to measured plant data. These comparisons show that the TU Electric reactor physics models accurately predict important measured parameters for power reactors

  5. RA3: Application of a calculation model for fuel management with SEFE (Slightly Enriched Fuel Elements)

    International Nuclear Information System (INIS)

    Estryk, G.; Higa, M.

    1993-01-01

    The RA-3 (5 MW, MTR) reactor is mainly utilized to produce radioisotopes (Mo-99, I-131, etc.). It started operating with Low Enrichment Uranium (LEU) in 1990, and spends around 12 fuels per year. Although this consumption is small compared to a nuclear power station. It is important to do a good management of them. The present report describes: - A reactor model to perform the Fuel Shuffling. - Results of fuel management simulations for 2 and a half years of operation. Some features of the calculations can be summarized as follows: 1) A 3D calculation model is used with the code PUMA. It does not have experimental adjustments, except for some approximations in the reflector representation and predicts: power, flux distributions and reactivity of the core in an acceptable way. 2) Comparisons have been made with the measurements done in the commissioning with LEU fuels, and it has also been compared with the empirical method (the previous one) which had been used in the former times of operation with LEU fuel. 3) The number of points of the model is approximately 13500, an it can be run in 80386 personal computer. The present method has been verified as a good tool to perform the simulations for the fuel management of RA-3 reactor. It is expected to produce some economic advantages in: - Achieving a better utilization of the fuels. - Leaving more time of operation for radioisotopes production. The activation measurements through the whole core required by the previous method can be significantly reduced. (author)

  6. Tasks related to increase of RA reactor exploitation and experimental potential, 01. Designing the protection chamber in the RA reactor hall for handling the radioactive experimental equipment (I-II) Part II, Vol. II; Radovi na povecanju eksploatacionih i eksperimentalnih mogucnosti reaktora RA, 01. Projektovanje zastitne komore u hali reaktora RA za rad sa aktivnim eksperimentalnim uredjajima (I-II), II Deo, Album II

    Energy Technology Data Exchange (ETDEWEB)

    Pavicevic, M [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1963-07-15

    This second volume of the project for construction of the protection chamber in the RA reactor hall for handling the radioactive devices includes the technical description of the chamber, calculation of the shielding wall thickness, bottom lead plate, horizontal stability of the chamber, cost estimation, and the engineering drawings.

  7. Transient performance and design aspects of low boron PWR cores with increased utilization of burnable absorbers

    International Nuclear Information System (INIS)

    Papukchiev, Angel; Schaefer, Anselm

    2008-01-01

    In conventional pressurized water reactor (PWR) designs, soluble boron is used for reactivity control over core fuel cycle. As high boron concentrations have significant impact on reactivity feedback properties and core transient behaviour, design changes to reduce boron concentration in the reactor coolant are of general interest in view of improving PWR inherent safety. In order to assess the potential advantages of such strategies in current PWRs, two low boron core configurations based on fuel with increased utilization of gadolinium and erbium burnable absorbers have been developed. The new PWR designs permit to reduce the natural boron concentration in reactor coolant at begin of cycle to 518 (Gd) and 805 (Er) ppm. An innovative low boron core design methodology was implemented combining a simplified reactivity balance search procedure with a core design approach based on detailed 3D diffusion calculations. Fuel cross sections needed for nuclear libraries were generated using the 2D lattice code HELIOS [2] and full core configurations were modelled with the 3D diffusion code QUABOX/CUBBOX [3]. For dynamic 3D calculations, the coupled code system ATHLET - QUABOX/CUBBOX was used [4]. The new cores meet German acceptance criteria regarding stuck rod, departure from nucleate boiling ratio (DNBR), shutdown margin, and maximal linear power. For the assessment of potential safety advantages of the new cores, comparative analyses were performed for three PWR core designs: the already mentioned two low boron designs and a standard design. The improved safety performance of the low boron cores in anticipated transients without scram (ATWS), boron dilution scenarios and beyond design basis accidents (BDBA) has already been reported in [1, 2 and 3]. This paper gives a short reminder on the results obtained. Moreover, it deals not only with the potential advantages, but also addresses the drawbacks of the new PWR configurations - complex core design, increased power

  8. Dosimetry and radiation shielding at the RA reactor, Annual report 1975, Annex 5; Prilog 5 - Dozimetrija i tehnicka zastita

    Energy Technology Data Exchange (ETDEWEB)

    Ninkovic, M [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1976-01-15

    In the working environment at the RA reactor, the level of gamma radiation is measured continuously by the built-in stationary system. According to the needs, measurement are done in the reactor hall every day. The level of gamma radiation is measured separately in typical points when the reactor is operated at nominal power and during intervals between two operating campaigns. The level of neutron radiation is measured according to the needs by means of a mobile spherical neutron detector. These measurements are done in the reactor hall around the horizontal experimental channels. Measured values of neutron radiation are three times lower than the relevant levels of gamma radiation. [Serbo-Croat] Na reaktoru RA vrsi se stalna kontrola nivoa gama zracenja po tehnoloskim i radnim prostorijama, pomocu ugradjenog stacionarnog sistema. Svakodnevno se vrse merenja u reaktorskoj hali, prema ukazanim potrebama. Posebno se mere nivoi gamma zracenja u karakteristicnim tackama pri radu reaktora na nominalnoj snazi i u pauzama izmedju dva kampanje. Merenje nivoa neutronskog zracenja vrsi se diskontinualno pomocu mobilnog sfernog neutronskog dozimetra. Merenja se obavljaju u hali oko horizontalnih eksperimentalnih kanala. Izmerene vrednosti su u proseku tri puta manje od odgovarajucih nivoa gama zracenja.

  9. Neutron Damage in Steels Containing Small Amounts of Boron

    Energy Technology Data Exchange (ETDEWEB)

    Myers, H P

    1961-05-15

    Certain low alloy steels contain small amounts (0.003 to 0.007 w/o) of boron which element contributes to the development of the air hardening properties of these steels. Such steels appear attractive for reactor pressure vessel construction but the question arises whether they will, due to the (n,{alpha}) reaction in boron, be more susceptible to neutron radiation damage than other steels which do not contain boron. We have attempted to estimate the importance of damage arising through boron fission relative to that caused by fast neutrons by assuming that the two sources of damage will be proportional to the numbers of displaced atoms produced in the two processes when no annealing or re combination of defects occurs. Within the approximations used we conclude that in a neutron spectrum which may be represented by an equivalent thermal flux {phi}{sub t} and an equivalent fast flux at 1 MeV of {phi}{sub f}, then D, the ratio of damage to boron fission to that caused by fast neutrons, is D = 4.5 x 10{sup -2} {phi}{sub t}/{phi}{sub f} (for 0. 003 w/o B). For the conditions at the inside of the reactor tank to R3 this would imply D = 1.2 x 10{sup -2} , i.e. if the R3 tank were built with a steel containing 0.003 w/o B then damage due to boron fission would be only {approx} 1 % of that caused by fast neutrons. Further problems with such steels as here discussed are the probability of embrittlement due to the introduction of boron fission fragments lithium and helium and the possibility of a radiation enhanced diffusion of boron which might lead to accentuated slow strain rate embrittlement. We argue that none of these problems should arise. It is concluded that a constructional steel containing 0.003 to 0.007 w/o B should not on this account be more susceptible to radiation damage than other non boron containing steels.

  10. Hydroxyapatite particles as carriers for "2"2"3Ra

    International Nuclear Information System (INIS)

    Vasiliev, A.N.

    2017-01-01

    Systematic investigation of optimal conditions for preparation and in vitro stability of HAP particles labeled with "2"2"3Ra, that could be considered as promising candidates for targeted α-therapy, has been carried out. Two different approaches to HAP labelling were tested: sorption of Ra"2"+ on pre-synthesized HAP-particles and incorporation of Ra"2"+ into the structure of HAP during its synthesis. Two textural forms of HAP particles were used-nanoparticles and particles with the diameter of 350 ± 20 μm. Kinetics of "2"2"3Ra sorption on HAP of different particle size and desorption in 0.9 % NaCl solution were studied. The influence of solution acidity and solid to liquid phase ratio on sorption of Ra was evaluated and the sorption yield up to 98 % was achieved. It was found that the optimal conditions for the sorption included synthesis of HAP nanoparticles in the presence of "2"2"3Ra at pH values of 4-7 followed by annealing at 900 deg C. In this case subsequent cumulative desorption of Ra was <5 % of initial activity. (author)

  11. RA Reactor operation and maintenance (I-IX), part V, Task 3.08/04-06, Refurbishment of the heavy water pumps

    International Nuclear Information System (INIS)

    Zecevic, V.; Nikolic, M.; Milic, J.

    1963-12-01

    In addition to detailed instructions for maintenance and repair of the heavy water pumps at the RA reactor this document includes nine annexes. They are as follows: cleaning the heavy water pump Avala with distilled water; instructions for repair of the pump CEN-132 (two annexes); list of operating characteristics of the pumps before repair; conclusions of the experts concerning the worn out bearings of the heavy water pump Avala, with the analysis of the stellite layer; report on the completed repair actions on the pumps Avala and CEN-132; report on the measurements done on the pump Avala; and the certificate concerning inspection of the pump

  12. Planning the RA reactor fuel exchange - Task 3.08/03; Zadatak 3.08/03 - Planiranje izmene goriva reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

    Dobrosavljevic, N; Strugar, P [Institute of Nuclear Sciences Boris Kidric, Reaktor RA, Vinca, Beograd (Serbia and Montenegro)

    1963-12-15

    From the reactor start-up until January 1963, after reactor operation of 1246 MWd , there was a need for fuel exchange. It was necessary to develop a method for planning the refuelling scheme which would enable economic and most appropriate further operation. The most suitable scheme for refuelling would be continuous exchange, but this cannot be performed since each fuel exchange demand reactor shutdown of approximately 15 days. For that reason a compromise scheme was adopted, meaning the fresh fuel is added after each 60-80 days of operation. This report describes the method for approximate calculation of reactivity increase during exchange of the spent fuel element with the fresh one. Detailed plan for exchange of fuel exchange is given in the conclusions.

  13. Activity of the Service for maintenance of the electronic equipment of the RA reactor in 1976, report - Annex IV

    International Nuclear Information System (INIS)

    Milosevic, M.

    1976-01-01

    Within the organizational structure of the RA reactor staff, the Service for instrumentation maintenance has the following tasks: maintenance of the existing electronic equipment; participating in experiments planning and preparation of electronic equipment; purchasing new equipment, spare parts and components; construction of new equipment for internal needs; implementation of new equipment. Basic instrumentation of the reactor facility includes: control and protection system, and dosimetry system [sr

  14. A study on the boron injection initiation temperature curve of BWR

    International Nuclear Information System (INIS)

    Wang, S.-J.; Chien, C.-S.; Fann, S.-Y.; Chiang, S.-C.

    2007-01-01

    Boron injection initiation temperature (BIIT) provides important information for the safe shutdown of the reactor using boron injection system during anticipated transient without scram (ATWS). The purpose of this paper is to study BIIT curve of boiling water reactor owners' group (BWROG). The unreasonable and non-conservative parts of BIIT are pointed out and suggested modifications are made. The starting reactor power of BIIT is increased in order to meet the actual application. The lower limit of suppression pool temperature of BIIT is revised for conservative operation during ATWS conditions. Analysis of the effects of maximum temperature capacity of the suppression chamber and concentration of boron in standby liquid control tank shows that BIIT is decreased by adopting a more conservative value of maximum temperature capacity of the suppression chamber. Consequently, early boron injection is anticipated. For system with automatic boron injection system, BIIT is not required

  15. Boron Neutron Capture Therapy at European research reactors - Status and perspectives

    International Nuclear Information System (INIS)

    Moss, R.L.

    2004-01-01

    Over the last decade. there has been a significant revival in the development of Boron Neutron Capture Therapy (BNCT) as a treatment modality for curing cancerous tumours, especially glioblastoma multiforme and subcutaneous malignant melanoma. In 1987 a European Collaboration on BNCT was formed, with the prime task to identify suitable research reactors in Europe where BNCT could be applied. Due to reasons discussed in this paper, the HFR Petten was chosen as the test-bed for demonstrating BNCT. Currently, the European Collaboration is approaching the start of clinical trials, using epithermal neutrons and borocaptate sodium (BSH) as the 10 B delivery agent. The treatment is planned to start in the first half of 1996. The paper here presents an overview on the principle of BNCT, the requirements imposed on a research reactor in order to be considered for BNCT, and the perspectives for other European materials testing reactors. A brief summary on the current status of the work at Petten is given, including: the design, construction and characterisation of the epithermal neutron beam: performance and results of the healthy tissue tolerance study; the development of a treatment planning programme based on the Monte Carlo code MCNP; the design of an irradiation room; and on the clinical trials themselves. (author)

  16. Report on participation of the operational dosimetry division in refurbishment of the RA reactor, Task 3.08/04-13; Podzadatak 3.08/04-13 Izvestaj o ucescu Odseka operativne dozimetrije RZ u remontnim radovima na Reaktoru RA

    Energy Technology Data Exchange (ETDEWEB)

    Ninkovic, M [Institute of Nuclear Sciences Boris Kidric, Reaktor RA, Vinca, Beograd (Serbia and Montenegro)

    1963-12-15

    During the refurbishment of the RA reactor, from January to June 1963 the division of operational division had a very important role and comprehensive tasks. To enable safety of the staff it was necessary to provide protection clothes, personnel dosemeters; permanent monitoring of radiation doses; strict control of the procedures for completing the planned maintenance and repair operations to avoid contamination of the personnel and working space. The refurbishment activities described in this report are: removal of fuel from the core; refurbishment of the heavy water system; decontamination of the distillation equipment; repair of the gas system.

  17. Anticipated transient without scram analysis of the simplified boiling water reactor following main steam isolation valve closure with boron injection

    International Nuclear Information System (INIS)

    Khan, H.J.; Cheng, H.S.; Rohatgi, U.S.

    1996-01-01

    The simplified boiling water reactor (SBWR) operating in natural circulation is designed with many passive safety features. An anticipated transient without scram (ATWS) initiated by inadvertent closure of the main steam isolation valve (MSIV) in an SBWR has been analyzed using the RAMONA-4B code of Brookhaven National Laboratory. This analysis demonstrates the predicted performance of the SBWR during an MSIV closure ATWS, followed by shutdown of the reactor through injection of boron into the reactor core from the standby liquid control system

  18. Prompt gamma neutron activation analysis facility at the RA-6 research reactor

    International Nuclear Information System (INIS)

    Sanchez, F. A.; Calzetta, O

    2004-01-01

    A prompt gamma neutron activation activation analysis facility was developed at the 500 kw thermal power RA-6 research reactor of the Bariloche Atomic Center, Argentina.This facility consist of a radial beam port with external positioning of the sample.The gamma radiation is reduced by a bismuth filter placed inside the extraction tube and the beam diameter is limited by a set of two collimators up to 5 cm.The neutron flux at the sample position is 7 10 6 n/cm 2 s with a Cadmium ratio of 20/1.The gamma detector is a 50 % efficiency type p HPGe rounded by a NaI(Tl) for Compton suppressioning.The gamma spectra is measured through 0 to 8.5 MeV.The background have counting rate of 350 cps without sample. In this work is shown the efficiency curve, the calculed sensibilities and the lower detection limits for B, Cd, Sm, Gd, H, Cl, Hg, Eu, Ti, Ag, Au, Mo. The RA-6's PGNAA facility is fully working, although the analytic capacity is under improvement [es

  19. Feasibility of ISO 14000 certification for the RA-6 reactor of the Bariloche Atomic Center

    International Nuclear Information System (INIS)

    Gho, Carlos J.

    2003-01-01

    The strengths and weaknesses of a proposal to set up a System for the Environmental Management of RA-6 reactor are reviewed. With this aim: The facility, its surroundings, its institutional frame, and the links of both the National Atomic Energy Commission and the Bariloche Atomic Center with the environmental issues are described. The RA-6 past and present regarding the environment is analyzed. The existence of an abundant documentation on procedures and manuals for administrative and technical management, as well as records of environmental behavior is determined. A summary is made of the work done with the staff in order to assess their motivation to develop this type of initiative, and their degree of knowledge and awareness of environmental issues. It is worthy to point out the high professional training of the RA-6 staff. This information is analyzed under the point of view of ISO 14001 both text and philosophy. It is shown that there exist important strengths that enable to face a concrete project, and that the weaknesses are few, most of them can be overcome somehow easily. The opportunity is remarkable. Conclusion is made that RA-6 is not only in optimal conditions to face successfully the implementation of an Environmental Management System, but it has already a rudimentary one

  20. Activities of the Service for maintenance of the RA reactor electronic equipment in 1979 - Report - Annex IV; Prilog IV Rad sluzbe za odrzavanje elektronske opreme reaktora RA u 1979. godini - Izvestaj -

    Energy Technology Data Exchange (ETDEWEB)

    Milosevic, M [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1979-12-15

    Within the organizational structure of the RA reactor staff, the Service for instrumentation maintenance has the following tasks: maintenance of the existing electronic equipment; participating in experiments planning and preparation of electronic equipment; purchasing new equipment, spare parts and components; construction of new equipment for internal needs; implementation of new equipment. Basic instrumentation of the reactor facility includes: control and protection system, and dosimetry system. [Serbo-Croat] U okviru organizacione seme OOUR nuklearni reaktor RA sluzba za odrzavanje instrumentacije postrojenja ima sledece zadatke: odrzavanje postojece elektronske opreme; ucesce u planiranju eksperimenata i priprema elektronske opreme; nabavka nove opreme, rezervnih delova i komponenti; rad na izradi elektronske opreme i uredjaja za sopstvene potrebe i izrada projekata u domenu reaktorske opreme i ucesce u ugradnji nove opreme. Osnovna instrumentacija postrojenja obuhvata: sistem za upravljanje i zastitu, sistem za tehnolosku kontrolu i sistem za dozimetrijsku kontrolu.

  1. Project requirements for reconstruction of the RA reactor ventilation system, Task 2.8. Measurement of radioactive iodine and other isotopes contents in the gas system of the RA reactor, Annex of the task

    International Nuclear Information System (INIS)

    Vujisic, Lj. et al

    1981-01-01

    This report is a supplement to the task 2.8. When planning and constructing the ventilation system, it was found that it is necessary to perform additional experiments during RA reactor operation at 2 MW power level for a longer period. In addition to the helium system, the potential source of radioactive pollutants is the space below the upper water shielding of the reactor. All the experimental and fuel channels are ending in this space. During repair and fuel exchange radioactivity can be released in this space. For that reason this space is important when planing and designing the filtration system for incidental conditions or planned dehermetisation of the reactor. The third point where radioactive isotope identification was done, was the entrance into the chimney during steady state operation and planned dehermetisation of the reactor. The following samples were measured: gas system during reactor operation at 2 MW power; entrance into the chimney during last 48 hours of reactor operation at 2 MW power; sample on the platform under the upper water shield with the opened fuel channel after the reactor shutdown; and simultaneously with the latter, measurement at the entrance to the chimney. This annex contains the list of identified radioactive isotopes, volatile and gaseous as well as concentration of volatile 131 I on the adsorbents [sr

  2. Decision, Annex 3[Organizational structure of the Division for reactor maintenance]; Prilog br. 3, Odluka

    Energy Technology Data Exchange (ETDEWEB)

    Pavicevic, M [Reaktor RA, Odelenje odrzavanja, Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1965-12-15

    The objective of the decision about the change in the organizational scheme of the Division for RA reactor maintenance is to achieve efficiency. The tasks are precisely defined as to divide the maintenance and repair tasks from special ones related to improvement of reactor operation its applicability. [Serbo-Croat] U cilju poboljsanja organizacije rada Odelenja odrzavanja reaktora RA, kao i efikasnijeg koriscenja raspolozivog kadra izvrsice se razgranicenje poslova odrzavanja i remonta od posebnih zadataka koji se odnose na poboljsanje rada reaktora i povecanje njegovih mogucnosti.

  3. Radiation protection at the RA nuclear reactor in 1987, Part II.a. Control of radioactivity in the environment of the RA nuclear reactor (precipitation, fallout, water, soil, plants, fruit)

    International Nuclear Information System (INIS)

    Martic, M.; Ajdacic, N.; Jovanovic, J.

    1987-01-01

    Control of radioactivity in the biosphere in the vicinity of the RA reactor is part of the radioactivity control done regularly for the whole territory of the Vinca Institute. According to the measurements during 1987 it was found that the total contamination of the precipitation was highest in January compared to the period before Chernobylsk accident. Mean monthly value of the total beta cavity was highest in April 5.41 times higher than the relevant value in 1986. This is a preliminary report, the measurement data will be presented after after analysis in the annual report [sr

  4. Radiation protection at the RA Reactor in 1989, Part -2, Decontamination, collection of treatment of fluid and solid radioactive waste, Annex 3; Deo 2 - Zastita od zracenja kod reaktora RA u 1989. godini, Dekontaminacija i intervencija, sakupljanje i obrada tecnih i cvrstih radioaktivnih otpadnih materija za potrebe reaktora RA - Prilog 3

    Energy Technology Data Exchange (ETDEWEB)

    Mandic, M; Vukovic, Z; Plecas, I; Knezevic, Lj; Lazic, S; Bacic, S [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1989-12-15

    Certain amount of solid waste results from RA reactor operation, the mean quantity of which depends on the duration of reactor operation and related activities. During repair, when reactor is not operated as well under accidental conditions, the quantity of waste is higher, dependent on the type of repair and comprehensiveness of decontamination of the working surface, contaminated tools and components. The waste is sorted and packed on the spot where they appeared according to the existing regulations and principles of radiation protection with aim to minimize unnecessary exposure of the radiation protection personnel who deals with control, transport, radioactive waste treatment and decontamination. During exceptional operations (decontamination, repair, bigger volume of contaminated material, etc.) professional staff of the Radiation protection department gives recommendations and helps in planning the actions related to repair, sorting and packaging of radioactive waste in special containers, identification of the contaminants, etc. [Serbo-Croat] Tokom rada reaktora RA dolazi do stvaranja odredjenih cvrstih otpadnih materijala cija prosecna kolicina zavisi od vremena rada reaktora i aktivnosti koje se tamo obavljaju. Tokom remonta, kada reaktor ne radi kao i pri akcidentalnim situacijama nastaju vece kolicine otpadnih materijala koje zavise od obima i vrste remontnih operacija i obima dekontaminacije kontaminirane radne povrsine i kontaminiranog alata, predmeta, opreme, itd. Nastali otpadni materijali se razvrstavaju i pakuju na mestu nastanka prema odgovarajucim propisima u skladu sa principima zastite od zracenja i aspekta bezbednosti u cilju minimiziranja nepotrebnog ozracivanja ljudstva za preuzimanje, kontrolu, transport, naknadnu obradu RAO i dekontaminaciju. Pri nerutinskim operacijama (dekontaminacija, remont, kontaminiarni otpadni materijal velike zapremine i sl.), strucna sluzba Institita ZASTITA pruza strucne konsultacije i pomaze pri planiranju

  5. Model for calculating the boron concentration in PWR type reactors

    International Nuclear Information System (INIS)

    Reis Martins Junior, L.L. dos; Vanni, E.A.

    1986-01-01

    A PWR boron concentration model has been developed for use with RETRAN code. The concentration model calculates the boron mass balance in the primary circuit as the injected boron mixes and is transported through the same circuit. RETRAN control blocks are used to calculate the boron concentration in fluid volumes during steady-state and transient conditions. The boron reactivity worth is obtained from the core concentration and used in RETRAN point kinetics model. A FSAR type analysis of a Steam Line Break Accident in Angra I plant was selected to test the model and the results obtained indicate a sucessfull performance. (Author) [pt

  6. Consolidation of the neutron spectrum in the RA-6 reactor

    International Nuclear Information System (INIS)

    Bazzana, S.; Chiaraviglio, N.

    2013-01-01

    Unfolding procedures can be used to determine the neutron or gamma spectrum in a multigroup structure from experimental and calculation results. In this way, it is possible to adjust with high reliability magnitudes that cannot be directly measured. For neutron unfolding it is necessary the use of a set of detectors with different energetic response. In this work we describe two unfolding experiences in different positions of the RA-6 reactor of the Bariloche Atomic Centre. One of them consisted in the unfolding in an incore position and the other one in the BNCT facility beam.Experimental techniques and neutron detectors for each experience are described along with the correction factors that must be taken into account for each experience. In both cases there is good agreement between measured and adjusted quantities. (author) [es

  7. Potential for boron dilution during small-break LOCAs in PWRs

    International Nuclear Information System (INIS)

    Nourbakhsh, H.P.; Cheng, Z.

    1995-01-01

    This paper documents the results of a scoping study of boron dilution and mixing phenomena during small break loss of coolant accidents (LOCAs) in pressurized water reactors (PWRs). Boron free condensate can accumulate in the cold leg loop seals when the reactor is operating in a reflux/boiler condenser mode. A problem may occur when the subsequent change in flow conditions such as loop seal clearing or re-establishment of natural circulation flow drive the diluted water in the loop seals into the reactor core without sufficient mixing with the highly borated water in the reactor downcomer and lower plenum. The resulting low boron concentration coolant entering the core may cause a power excursion leading to fuel failure. The mixing processes associated with a slow moving stream of diluted water through the loop seal to the core were examined in this report. A bounding evaluation of the range of boron concentration entering the core during a small break LOCA in a typical Westinghouse-designed, four-loop plant is also presented in this report

  8. Activity of the Service for maintenance of mechanical structures of the RA reactor - Report for 1980, Annex II; Prilog II - Rad sluzbe za odrzavanje masinske opreme reaktora RA - Izvestaj za 1980. god

    Energy Technology Data Exchange (ETDEWEB)

    Radivojevic, J [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1980-12-15

    Service for mechanical components at the RA reactor includes: control and maintenance of utility components, mechanical workshop, hot cells and storage. Control and maintenance of main components covers: reactor core, heavy water system, technical water system, gas system. This service is responsible for the following auxiliary systems: transportation units; spent fuel storage pool; special ventilation system; personal protection appliances; hot cells. Maintenance of the reactor building, ventilation, heating, water supply, sewage, fire protection devices, gas and compressed air systems are included. [Serbo-Croat] Sluzba za masinsku opremu nuklearnog reaktora RA obuhvata: kontrolu i odrzavanje masinske opreme postrojenja, masinsku radionicu, vruce komore i prirucni magacin. Kontrola i odrzavanje osnovnih sistema obuhvata centralno telo reaktora, sistem teske vode, sistem tehnicke vode, gasni sistem. Pomocni sistemi koji spadaju u delatnost ove sluzbe su: transportna oprema, bazen za odlezavanje ozracenog goriva, sistem specijalne ventilacije, licna zastitna sredstva, vruce komore. Odrzavanje zgrade reaktora, ventilacije i grejanja, vodovoda i kanalizacije, opreme za protivpozarnu zastitu, instalacije gasa i komprimovanog vazduha su takode zadatak ove Sluzbe.

  9. Boron delivery with liposomes for boron neutron capture therapy (BNCT): biodistribution studies in an experimental model of oral cancer demonstrating therapeutic potential

    International Nuclear Information System (INIS)

    Nigg, David W.

    2012-01-01

    Boron neutron capture therapy (BNCT) combines selective accumulation of 10B carriers in tumor tissue with subsequent neutron irradiation. We previously demonstrated the therapeutic efficacy of BNCT in the hamster cheek pouch oral cancer model. Optimization of BNCT depends largely on improving boron targeting to tumor cells. Seeking to maximize the potential of BNCT for the treatment for head and neck cancer, the aim of the present study was to perform boron biodistribution studies in the oral cancer model employing two different liposome formulations that were previously tested for a different pathology, i.e., in experimental mammary carcinoma in BALB/c mice: (1) MAC: liposomes incorporating K(nido-7-CH3(CH2)15-7,8-C2B9H11) in the bilayer membrane and encapsulating a hypertonic buffer, administered intravenously at 6 mg B per kg body weight, and (2) MAC-TAC: liposomes incorporating K(nido-7-CH3(CH2)15-7,8-C2B9H11) in the bilayer membrane and encapsulating a concentrated aqueous solution of the hydrophilic species Na3 (ae-B20H17NH3), administered intravenously at 18 mg B per kg body weight. Samples of tumor, precancerous and normal pouch tissue, spleen, liver, kidney, and blood were taken at different times post-administration and processed to measure boron content by inductively coupled plasma mass spectrometry. No ostensible clinical toxic effects were observed with the selected formulations. Both MAC and MAC-TAC delivered boron selectively to tumor tissue. Absolute tumor values for MAC-TAC peaked to 66.6 ± 16.1 ppm at 48 h and to 43.9 ± 17.6 ppm at 54 h with very favorable ratios of tumor boron relative to precancerous and normal tissue, making these protocols particularly worthy of radiobiological assessment. Boron concentration values obtained would result in therapeutic BNCT doses in tumor without exceeding radiotolerance in precancerous/normal tissue at the thermal neutron facility at RA-3.

  10. Boron delivery with liposomes for boron neutron capture therapy (BNCT): biodistribution studies in an experimental model of oral cancer demonstrating therapeutic potential

    Energy Technology Data Exchange (ETDEWEB)

    David W. Nigg

    2012-05-01

    Boron neutron capture therapy (BNCT) combines selective accumulation of 10B carriers in tumor tissue with subsequent neutron irradiation. We previously demonstrated the therapeutic efficacy of BNCT in the hamster cheek pouch oral cancer model. Optimization of BNCT depends largely on improving boron targeting to tumor cells. Seeking to maximize the potential of BNCT for the treatment for head and neck cancer, the aim of the present study was to perform boron biodistribution studies in the oral cancer model employing two different liposome formulations that were previously tested for a different pathology, i.e., in experimental mammary carcinoma in BALB/c mice: (1) MAC: liposomes incorporating K[nido-7-CH3(CH2)15-7,8-C2B9H11] in the bilayer membrane and encapsulating a hypertonic buffer, administered intravenously at 6 mg B per kg body weight, and (2) MAC-TAC: liposomes incorporating K[nido-7-CH3(CH2)15-7,8-C2B9H11] in the bilayer membrane and encapsulating a concentrated aqueous solution of the hydrophilic species Na3 [ae-B20H17NH3], administered intravenously at 18 mg B per kg body weight. Samples of tumor, precancerous and normal pouch tissue, spleen, liver, kidney, and blood were taken at different times post-administration and processed to measure boron content by inductively coupled plasma mass spectrometry. No ostensible clinical toxic effects were observed with the selected formulations. Both MAC and MAC-TAC delivered boron selectively to tumor tissue. Absolute tumor values for MAC-TAC peaked to 66.6 {+-} 16.1 ppm at 48 h and to 43.9 {+-} 17.6 ppm at 54 h with very favorable ratios of tumor boron relative to precancerous and normal tissue, making these protocols particularly worthy of radiobiological assessment. Boron concentration values obtained would result in therapeutic BNCT doses in tumor without exceeding radiotolerance in precancerous/normal tissue at the thermal neutron facility at RA-3.

  11. Utilization of boron irradiation filters in reactor neutron activation via epithermal (n,γ) and fast neutron reactions

    International Nuclear Information System (INIS)

    Chisela, F.

    1986-01-01

    The technique of instrumental neutron activation analysis based on irradiation with reactor epithermal and fast neutrons has been described and evaluated. Important characteristics of boron neutron absorbers used to remove thermal neutrons from the reactor neutron spectrum have been examined and compared with those of cadmium. Three boron compound shields, have been designed and constructed at the BER II 5MW reactor for use in epithermal neutron activation analysis of biological materials. The major advantages offered by these filters in this application include the flexibility of varying the filter thickness, the low radioactivity induced in the filters during irradiation, ease of fabrication and the relatively low cost of the filter materials. The radiation heating due to the 10 B(n,α) 7 Li-reaction has been experimentally investigated for the filters used and the results obtained confirm the necessity for efficient cooling of these filters during irradiation. Three irradiation facilities have been characterized with respect to the neutron flux density and the flux spatial distribution. An experiment has been designed and carried out to compensate the flux inhomogeneity in two irradiation positions of the DBV facility caused by the reactor geometry. Several biological samples including well characterized reference materials have been analysed after epithermal activation and the results compared with those obtained with the classical thermal neutron activation method. Improved sensitivity of determination has been found for elements with high resonance integral to thermal neutron cross section ratios (RI/σ 0 ). The range of elements that can be determined instrumentally is extended and the time scale of analysis is considerably reduced. (orig.) [de

  12. An analysis on boron dilution events during SBLOCA for the KNGR

    International Nuclear Information System (INIS)

    Kim, Young In; Hwang, Young Dong; Park, Jong Kuen; Chung, Young Jong; Sim, Suk Gu

    1999-02-01

    An analysis on boron dilution events during small break loss of coolant accident (LOCA) for Korea Next Generation Reactor (KNGR) was performed using Computational Fluid Dynamic (CFD) computer program FLUENT code. The maximum size of the water slug was determined based on the source of un borated water slug and the possible flow paths. Axisymmetric computational fluid dynamic analysis model is applied for conservative scoping analysis of un borated water slug mixing with recirculation water of the reactor system following small break LOCA assuming one Reactor Coolant Pump (RCP) restart. The computation grid was determined through the sensitivity study on the grid size, which calculates the most conservative results, and the preliminary calculation for boron mixing was performed using the grid. (Author). 17 refs., 3 tabs., 26 figs

  13. 3M"T"M neutron quench. Compounds with substantial water solubility and boron content

    International Nuclear Information System (INIS)

    Cook, Kevin S.; Blake, Alex B.; Neef, C. Jody

    2014-01-01

    Of the two naturally occurring isotopes of boron ("1"1B 80%, "1"0B 20%), "1"0B is a good neutron absorber with a thermal neutron absorption cross section of ∼3800 barns. The ability to absorb thermal neutrons while producing benign reaction products makes boron an ideal atom to aid in the control and arrest of the fission reaction in nuclear power reactors. In current practice, boric acid and sodium pentaborate are commonly used as neutron absorbers in the water regime of active and passive safety systems. 3M"T"M Neutron Quench compounds have been developed to be applied in situations where criticality control needs exceed normal control methods. In this type of situation these compounds have several advantages over commonly used neutron absorbers like boric acid: Boron Content; compounds contain up to 80 wt% boron compared to 16 wt% for boric acid and sodium pentaborate. Solubility; >16 g B/100 g solution compared to 0.6 g B/100 g solution for boric acid at 25°C. pH neutrality; compounds demonstrate pH neutrality even in concentrated solutions. Thermal Stability; Compounds are stable as solids at temperatures greater than 500°C. Corrosiveness; Electrochemical corrosion rate studies have indicated that these compounds are significantly less corrosive than boric acid. Use of 3M"T"M Neutron Quench can lead to reduction in emergency shutdown pool size, reduce or remove the necessity for pool heating and heat tracing of lines, allow for more rapid introduction of the absorber in emergency situations or be used in other applications where significant neutron control is necessary. (author)

  14. Establishment of the operating procedure to prevent boron precipitation during Post-LOCA long term cooling for Korean Westinghouse 3-loop NPPs

    International Nuclear Information System (INIS)

    Choi, Han Rim; Kwon, Tae Soon; Ban, Chang Hwan; Jeong, Jae Hoon; Lee, Young Jin.

    1996-11-01

    During post-LOCA LTC the increase of the excess reactivity for the extended fuel cycle should require increasing the RWST boron concentration in order to ensure core subcritical state. To quantify the concentration increment, the calculation methods was developed for the post-LOCA RCS/Sump mixed mean boron concentration, which applied for Kori 3 and 4 and Ulchin 1 and 2 of the Westinghouse 3-loop nuclear power plants in Korean. From the calculation results, the minimum boric acid concentrations increased of the RWST and accumulator were determined consideration of the convenient operation for operator on reloading. Boric acid concentrations of the RWST and the accumulators for Westinghouse 3-loop type plants were increased to meet the post-LOCA shutdown requirement for the long life cycles from 12 months to 18 months. To maintain LTC capability following a LOCA, the switchover time is examined using boron code of prevent the boron precipitation in the reactor core with the increased boron concentrations. The analysis results showed that hot leg recirculation switchover times were shortened to 7.5 hours from 24 hours after the initiation of LOCA for Kori 3 and 4 and 8 hours from 18 hours for Ulchin 1 and 2, respectively. The flow path in the mode J for Kori 3 and 4 was recommended to realign to the simultaneous recirculation of both hot and cold legs from the cold leg recirculation, as done by Ulchin 1 and 2. (author). 2 tabs., 12 figs., 13 refs

  15. Devices for irradiation of materials in the fast neutron flux at the RA heavy water reactor in Vinca; Uredjaji za ozracivanje materijala u fluksu brzih neutrona na teskovodnom reaktoru RA u Vinci

    Energy Technology Data Exchange (ETDEWEB)

    Pavicevic, M [Institut za nuklearne nauke Boris Kidric, Vinca, Beograd (Yugoslavia)

    1964-07-01

    Full text: This paper covers the concept, technical description and problems of constructing special experimental facilities at the RA reactor in Vinca. During 1962, construction materials (graphite, Mg, Al-oxides, steel and Zircaloy) were irradiated in these facilities at temperatures below 100 deg C by the integral fast neutron flux of 2 10{sup 20} n/cm{sup 2}. Temperature of the samples cooled by heavy water circulating through hollow uranium elements was measured by thermocouples. Construction of the facility, sample preparation, related measurements of the flux and irradiation of the samples were done in cooperation with the Nuclear center in Saclay, France. A short review of the experiences in using the new experimental space at the RA reactor is given, together with some problems related to transport of radioactive capsules containing samples from Vinca to Saclay.

  16. RA Reactor operation and maintenance (I-IX), part V, Task 3.08/04-06, Refurbishment of the heavy water pumps; Pogon i odrzavanje reaktora RA (I-IX), V Deo, Zadatak 3.08/04-06 Remont teskovodnih pumpi

    Energy Technology Data Exchange (ETDEWEB)

    Zecevic, V; Nikolic, M; Milic, J [Institute of Nuclear Sciences Boris Kidric, Reaktor RA, Vinca, Beograd (Serbia and Montenegro)

    1963-12-15

    In addition to detailed instructions for maintenance and repair of the heavy water pumps at the RA reactor this document includes nine annexes. They are as follows: cleaning the heavy water pump Avala with distilled water; instructions for repair of the pump CEN-132 (two annexes); list of operating characteristics of the pumps before repair; conclusions of the experts concerning the worn out bearings of the heavy water pump Avala, with the analysis of the stellite layer; report on the completed repair actions on the pumps Avala and CEN-132; report on the measurements done on the pump Avala; and the certificate concerning inspection of the pump.

  17. Avalanche boron fusion by laser picosecond block ignition with magnetic trapping for clean and economic reactor

    Czech Academy of Sciences Publication Activity Database

    Hora, H.; Korn, Georg; Eliezer, S.; Nissim, N.; Lalousis, P.; Giuffrida, Lorenzo; Margarone, Daniele; Picciotto, A.; Miley, G. H.; Moustaizis, S.; Martinez-Val, J.M.; Barty, C.P.J.; Kirchhoff, G.J.

    2016-01-01

    Roč. 4, Oct (2016), 1-9, č. článku e35. ISSN 2095-4719 R&D Projects: GA MŠk EF15_008/0000162 Grant - others:ELI Beamlines(XE) CZ.02.1.01/0.0/0.0/15_008/0000162 Institutional support: RVO:68378271 Keywords : boron fusion energy * dielectric nonlinear force explosion * economic reactor * environmentally clean energy Subject RIV: BL - Plasma and Gas Discharge Physics

  18. Wireless condition monitoring for the RA-6 research reactor

    International Nuclear Information System (INIS)

    Garcia Peyrano, O.; Calzeta, O.; Rico, N.; Damiani, H.; Coutsiers, E.

    1999-01-01

    The vibration laboratory at C.A.B. has a great experience with the analysis and diagnostic of symptoms of failures in the rotating equipment of the R-6 research reactor and in our longest NPP (CANDU 600 Mw), located in Embalse town, Cordoba City, Argentina. Objective: The standard condition monitoring instrumentation system were designed for large equipment operating under different environmental conditions and sensitivities. The signal processing is not flexible and the diagnostic is an expensive method for the small poll type research reactors. This papers describes the research and development which are related whit the new concept, cheaper and flexible condition monitoring instrumentation system. Implementing a vibration analysis measurements technique with a sensor inside (in the pool) of the nuclear reactor RA-6, and mainly based on fft signal processing, an extensive program for vibration source identification was done. Different nuclear power conditions were monitored as full power and in zero power, also. This zero power shows the best acoustical environmental, because the cooling pumps are stop, and the core is cooling by natural convection. Two sensors were mainly used as the detector's subsystem. One of these detectors was an accelerometer attached to the top of the fine control rod and the other one was a water resistant omnidirectional microphone which was located underwater at different distances from the nuclear core. All the signal measurement by this two sensors were recorded and then was processed. Both signal was acquired at the same time for correlation analysis purposes. The analysis was composed by a 'Spectral Dynamics SD380' connected to a P.C. with dedicated post processing software. On the other hand, some calibration and sensitivity comparison was done using an SKFCM40, dual channel data collector and analyzer. (author)

  19. RA reactor safety analysis I-III, Part III - Environmental effect of the maximum credible accident; Analiza sigurnosti rada Reaktora RA I-III, III deo - Posledica maksimalno moguceg akcidenta na okolinu reaktora

    Energy Technology Data Exchange (ETDEWEB)

    Raisic, N [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1963-02-15

    The objective of the maximum credible accident analysis was to determine the integral radiation doses in the vicinity of the reactor and in the environment. In case of RA reactor the maximum credible accident, meaning release of the fission products, would be caused by fuel elements meltdown. This analysis includes the following calculation results: activity of the fission products, volatility of the fission products, concentration of radioactive materials in the air, analysis of the accident environmental effects.

  20. Design project of the dosimetry control system in the independent CO2 loop for cooling the samples irradiated in the RA reactor vertical experimental channels, Vol. V

    International Nuclear Information System (INIS)

    1964-01-01

    Design project of the dosimetry control system in the independent CO 2 loop for cooling the samples irradiated in the RA reactor vertical experimental channels includes the following: calculations of CO 2 gas activity, design of the dosimetry control system, review of the changes that should be done in the RA reactor building for installing the independent CO 2 loop, specification of the materials with cost estimation, engineering drawings of the system [sr

  1. Some local dilution transient in a pressurized water reactor

    International Nuclear Information System (INIS)

    Jacobson, S.

    1989-01-01

    Reactivity accidents are important in the safety analysis of a pressurized water reactor. In this anlysis ejected control rod, steam line break, start of in-active loop and boron dilution accidents are usually dealt with. However, in the analysis is not included what reactivity excursions might happen when a zone,depleted of boron passes the reactor core. This thesis investigates during what operation and emergency conditions diluted zones might exist in a pressurized water reactor and what should be the maximum volumes for then. The limiting transport means are also established in terms of reactivty addition, for the depleted zones. In order to describe the complicated mixing process in the reactor vessel during such a transportation, a typical 3-loop reactor vessel has been modulated by means of TRAC-PF1's VESSEL component. Three cases have been analysed. In the first case the reactor is in a cold condition and the ractor coolant has boron concentration of 2000 ppm. To the reactor vessel is injected an clean water colume of 14 m 3 . In the two other cases the reactor is close to hot shutdown and borated to 850 ppm. To the reactor vessel is added 41 and 13 m 3 clean water, respectively. In the thesis is shown what spatial distribution the depleted zone gets when passing through the reactor vessel in the three cases. The boron concentration in the first case did not decrease the values which would bring the reactor to critical condition. For case two was shown by means of TRAC's point kinetics model that the reactor reaches prompt criticality after 16.03 seconds after starting of the reactor coolant pump. Another prompt criticality occured two seconds later. The total energy developed during the two power escalations were about 55 GJ. A comparision with the criteria used to evaluate the ejected control rod reactivity transient showed that none of these criteria were exceeded. (64 figs.)

  2. Synthetic study of reactor irradiation for medical use

    International Nuclear Information System (INIS)

    An, Shigehiro; Furuhashi, Akira; Kanda, Keiji; Sumita, Kenji; Kakihana, Hidetake.

    1978-01-01

    This report is described on the results of the study on the reactor irradiation for medical use shared by the Nuclear Engineering Research Laboratory, Faculty of Engineering, University of Tokyo, and other seventeen facilities. Boron neutron-capturing therapy developed in Japan is extremely significant treating method for tumors by destroying tumor cells of encephaloma, etc. selectively. This is the synthetic study for promoting the above therapeutic method. Two existing reactors were reconstructed into the thermal neutron reactors for boron neutron-capturing therapy. The various preparatory and physical researches were made with the reconstruction, and the therapy was tried on eleven cases. Further experiments were made on the following points: (1) To promote treatment on encephaloma by boron neutron-capturing therapy. (2) To develop its application to malignant tumors other than encephaloma. (3) Animal irradiation experiments. (4) The basic experiments on the cellular level. (5) The study of remote controlled anesthesia. (6) To control irradiated dose. (7) To improve boron compounds. (8) To condense radioisotopes. (Kobatake, H.)

  3. Safety analysis of RA reactor operation, I-III, Part III - Environmental effect of the maximum credible accident; Analiza sigurnosti rada reaktora RA - I-III, III deo - Posledica maksimalno moguceg akcidenta na okolinu reaktora

    Energy Technology Data Exchange (ETDEWEB)

    Raisic, N [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1963-02-15

    Maximum credible accident at the RA reactor would consider release of fission products into the environment. This would result from fuel elements failure or meltdown due to loss of coolant. The analysis presented in this report assumes that the reactor was operating at nominal power at the moment of maximum possible accident. The report includes calculations of fission products activity at the moment of accident, total activity release during the accident, concentration of radioactive material in the air in the reactor neighbourhood, and the analysis of accident environmental effects.

  4. Physical modelling of a rapid boron dilution transient

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, N.G.; Hemstroem, B.; Karlsson, R. [Vattenfall Utveckling AB, Aelvkarleby (Sweden); Jacobson, S. [Vattenfall AB, Ringhals, Vaeroebacka (Sweden)

    1995-09-01

    The analysis of boron dilution accidents in pressurised water reactors has traditionally assumed that mixing is instantaneous and complete everywhere, eliminating in this way the possibility of concentration inhomogeneities. Situations can nevertheless arise where a volume of coolant with a low boron concentration may eventually enter the core and generate a severe reactivity transient. The work presented in this paper deals with a category of Rapid Boron Dilution Events characterised by a rapid start of a Reactor Coolant Pump (RCP) with a plug of relatively unborated water present in the RCS pipe. Model tests have been made at Vattenfall Utveckling AB in a simplified 1:5 scale model of a Westinghouse PWR. Conductivity measurements are used to determine dimensionless boron concentration. The main purpose of this experimental work is to define an experimental benchmark against which a mathematical model can be tested. The final goal is to be able to numerically predict Boron Dilution Transients. This work has been performed as a part of a Co-operative Agreement with Electricite` de France (EDF).

  5. Investigation of the burn-up behavior of boron poison rods, placed in a fuel assembly of a pressurized water reactor

    International Nuclear Information System (INIS)

    Arnold, C.; Lutz, D.C.

    1979-09-01

    The excess reactivity of a pressurized water reactor is compensated by boron, disolved in the moderator. In addition during the first cycle boron poison rods are placed in fuel assemblies without control rods. The burn-up behavior of a poison rod in a Biblis B fuel assembly is analysed in the present paper. Multigroup spectrum calculations were performed. The influence of critical boron concentration depending from burn-up, the changes of fuel concentration and the concentration of burnable poison were taken into consideration. Furthermore the built-up of rapidly saturating fisson products 135 Xe and 149 Sm was considered. The interaction of these effects are discussed. Spatial influences are emphasized most. Finally two group cross sections were calculated. The results are compared with calculations for a fuel assembly of the same type without burnable poison rods. (orig.) [de

  6. OPTIMIZATION OF THE EPITHERMAL NEUTRON BEAM FOR BORON NEUTRON CAPTURE THERAPY AT THE BROOKHAVEN MEDICAL RESEARCH REACTOR.

    Energy Technology Data Exchange (ETDEWEB)

    HU,J.P.; RORER,D.C.; RECINIELLO,R.N.; HOLDEN,N.E.

    2002-08-18

    Clinical trials of Boron Neutron Capture Therapy for patients with malignant brain tumor had been carried out for half a decade, using an epithermal neutron beam at the Brookhaven's Medical Reactor. The decision to permanently close this reactor in 2000 cut short the efforts to implement a new conceptual design to optimize this beam in preparation for use with possible new protocols. Details of the conceptual design to produce a higher intensity, more forward-directed neutron beam with less contamination from gamma rays, fast and thermal neutrons are presented here for their potential applicability to other reactor facilities. Monte Carlo calculations were used to predict the flux and absorbed dose produced by the proposed design. The results were benchmarked by the dose rate and flux measurements taken at the facility then in use.

  7. Design and construction of demineralized water production and maintenance system for RA-O nuclear reactor

    International Nuclear Information System (INIS)

    Rumis, D.; Martin, H.R.

    1990-01-01

    The normal operation of zero power RA-O Nuclear Reactor requires a production and maintenance of demineralized water system. This system was designed and built-up during the works for actualization, upgrading and new start up at Cordoba National University of this facility. This paper comments the relevant aspects about the didactical purpose of that system and the details considered for training and practices with it. Similarly, considerations about solids wastes and effluents treatment are discussed. (Author)

  8. Mixing phenomena of interest to boron dilution during small break LOCAs in PWRs

    International Nuclear Information System (INIS)

    Nourbakhsh, H.P.; Cheng, Z.

    1995-01-01

    This paper presents the results of a study of mixing phenomena related to boron dilution during small break loss of coolant accidents (LOCAs)in pressurized water reactors (PWRs). Boron free condensate can accumulate in the cold leg loop seals when the reactor is operating in a reflux/boiler-condenser mode. A problem may occur when subsequent change in flow conditions such as loop seal clearing or re-establishment of natural circulation flow drive the diluted water in the loop seals into the reactor core without sufficient mixing with the highly borated water in the reactor downcomer and lower plenum. The resulting low boron concentration coolant entering the core may cause a power excursion leading to fuel failure. The mixing processes associated with a slow moving stream of diluted water through the loop seal to the core are examined in this paper. Bounding calculations for boron concentration of coolant entering the core during a small break LOCA in a typical Westinghouse-designed four-loop plant are also presented

  9. External irradiation of the personnel operating the reactor RA at Vinca in the period 1963-1966

    International Nuclear Information System (INIS)

    Ninkovic, M.M.; Minincic, Z.

    1968-06-01

    The paper first gives a survey of the characteristic operations performed on the Vinca reactor RA in which most of the personnel become irradiated. Following is a schematic diagram of the irradiations in the period 1963-1966 in which the reactor was in continual operation. The surveys are given for each month and each year separately, while the irradiated personnel are grouped in several characteristic irradiation dose ranges. In this analysis special emphasis is given to a survey of irradiation of the personnel classified according to their profession, i.e. their post. This kind of analysis is indispensable in planning work, proper disposition of the personnel and undertaking special protective measures for reducing the irradiations (author) [sr

  10. RA Research reactor, Annual report 1973; Istrazivacki nuklearni reaktor RA - Izvestaj za 1973. godinu - Pogon i odrzavanje

    Energy Technology Data Exchange (ETDEWEB)

    Milosevic, D et al. [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1973-12-15

    During 1973, RA reactor was operated at nominal power for 4687 hours and 54 hours at lower power levels. The total production was 30504 MWh which is 1.6% higher than planned. Practically there was no discrepancies from the plan, since the action plan was corrected at the beginning of this year caused by the demand of changing the schedule for refuelling for the purpose of 'power excursion' experiment. The reactor was used for irradiation and experiments according to the demand of 336 users. This report contains detailed data about reactor power and experiments performed in 1973. Total number safety shutdowns was 12, of which 7 were caused by power cuts. Three shutdowns caused by failures of the equipment were caused by failures of new electronic tubes. Two shutdowns were caused by the operators. There have been three shorter interruptions announced power cuts. Total personnel exposure dose was lower than during previous years. There were no accidents during this year. Decontamination of surfaces was less than during previous years. Practically there was no surface contamination, and the quantity of collected radioactive waste was lower than previously. There were no liquid radioactive effluents. It was concluded that the successful operation in 1973 has a special significance taking into account the financial crisis. There still remains a number of unsolved problems related to: completing the inventory of spare parts, exchange of some elements of the equipment, exchange of instrumentation, and purchase of the highly enriched fuel. [Serbo-Croat] Reaktor RA je u 1973. godini radio na nominalnoj snazi 4687 sati i 54 sata na manjim snagama. Ukupni rad iznosio je 30504 MWh odnosno 1,6% vise od planiranog. Prakticno nije bilo odstupanja od plana rada koji je pocetkom godine korigovan zbog promene planiranih izmena goriva usled izvodjenja eksperimenta 'ekskurzije snage'. Reaktor je koriscen za ozracivanja i eksperimente za 336 korisnika. Ovaj izvestaj sadrzi detaljne

  11. Practical experience for liquid radioactive waste treatment from spent fuel storage pool on RA reactor in Vinca Institute

    International Nuclear Information System (INIS)

    Plecas, I.; Pavlovic, R.; Pavlovic, S.

    2002-01-01

    The present paper reports the results of the preliminary removal of sludge from the bottom of the spent fuel storage pool in the RA reactor, mechanical filtration of the pool water and sludge conditioning and storage. Yugoslavia is a country without a nuclear power plant (NPP) on its territory. The law which strictly forbids NPP construction is still valid, but, nevertheless we must handle and dispose radioactive waste. This is not only because of radwaste originating from the use of radioactive materials in medicine and industry, but also because of the waste generated by research in the Nuclear Sciences Institute Vinca. In the last forty years, in the Vinca Institute, as a result of two research reactors being operational, named RA and RB, and as a result of the application of radionuclides in medicine, industry and agriculture, radioactive waste materials of different levels of specific activity were generated. As a temporary solution, radioactive waste materials are stored in two interim storages. Radwaste materials that were immobilized in the inactive matrices are to be placed in concrete containers, for further manipulation and disposal.(author)

  12. Devices for irradiation of materials in the fast neutron flux at the RA heavy water reactor in Vinca; Uredjaji za ozracivanje materijala u fluksu brzih neutrona na teskovodnom reaktoru RA u Vinci

    Energy Technology Data Exchange (ETDEWEB)

    Pavicevic, M [The Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

    1965-07-01

    Full text: This paper covers the concept, design description and problems of constructing special experimental devices at the RA reactor in Vinca. These devices were used for irradiation of construction materials (graphite, Mg and Al oxides, steel and zircaloy) in the integral fast neutron flux of 2 x 10{sup 20} n/cm{sup 2}. Temperature of samples cooled by heavy water circulating through the hollow uranium fuel elements was measured by thermocouples. Construction of the device, preparation of samples, related flux measurements as well as irradiation were done in cooperation with the nuclear center in Saclay, France. Brief review of the experiences gained in using these experimental spaces at the RA reactor as well as problems of transporting the irradiated capsules from Vinca to France is included. [Serbo-Croat] Pun tekst: Rad obuhvata koncepciju, tehnicki opis i probleme realizacije specijalnih eksperimentalnih uredjaja u reaktoru RA u Vinci, u kojima je tokom 1962. godine izvrseno, na temperaturama ispod 100 deg C, ozracivanje konstrukcionih materijala (grafita, Mg i Al-oksida, celika i cirkaloja) u integralnom fluksu brzih neutrona vrednosti 2 x 10{sup 20} n/cm{sup 2}. Temperatura uzoraka hladjenih teskom vodom, koja protice kroz suplje uranske elemente, merena je termoparovima. Realizacija uredjaja, priprema uzoraka, odgovarajuca merenja fluksa kao i sama ozracivanja vrsena su u saradnji sa Nuklearnim centrom u Saclay-u, Francuska. Dat je kraci pregled iskustava iz eksploatacije ovih novih eksperimentalnih prostora u reaktoru RA, kao i neki problemi vezani za transport aktivnih kapsula sa uzorcima od Vince do Saclay-a (author)

  13. A critical assessment of boron target compounds for boron neutron capture therapy.

    Science.gov (United States)

    Hawthorne, M Frederick; Lee, Mark W

    2003-01-01

    Boron neutron capture therapy (BNCT) has undergone dramatic developments since its inception by Locher in 1936 and the development of nuclear energy during World War II. The ensuing Cold War spawned the entirely new field of polyhedral borane chemistry, rapid advances in nuclear reactor technology and a corresponding increase in the number to reactors potentially available for BNCT. This effort has been largely oriented toward the eradication of glioblastoma multiforme (GBM) and melanoma with reduced interest in other types of malignancies. The design and synthesis of boron-10 target compounds needed for BNCT was not channeled to those types of compounds specifically required for GBM or melanoma. Consequently, a number of potentially useful boron agents are known which have not been biologically evaluated beyond a cursory examination and only three boron-10 enriched target species are approved for human use following their Investigational New Drug classification by the US Food and Drug Administration; BSH, BPA and GB-10. All ongoing clinical trials with GBM and melanoma are necessarily conducted with one of these three species and most often with BPA. The further development of BNCT is presently stalled by the absence of strong support for advanced compound evaluation and compound discovery driven by recent advances in biology and chemistry. A rigorous demonstration of BNCT efficacy surpassing that of currently available protocols has yet to be achieved. This article discusses the past history of compound development, contemporary problems such as compound classification and those problems which impede future advances. The latter include means for biological evaluation of new (and existing) boron target candidates at all stages of their development and the large-scale synthesis of boron target species for clinical trials and beyond. The future of BNCT is bright if latitude is given to the choice of clinical disease to be treated and if a recognized study

  14. A database model for the radiological characterization of the RA reactor in the 'Vinca' Institute

    International Nuclear Information System (INIS)

    Steljic, M.; Ljubenov, V.

    2004-01-01

    During the preparation and realization of the radiological characterization of nuclear facility it is necessary to organize, store, review and process large amount of various data types. The documentation has to be treated according to the quality assurance (QA) programme requirements, and to ultimate goal would be to establish the unique record management system (RMS) for the nuclear facility decommissioning project. This paper presents the design details of the database model for the radiological characterization of the RA research reactor (author) [sr

  15. Inspection experience with RA-3 spent nuclear fuel assemblies at CNEA's central storage facility

    International Nuclear Information System (INIS)

    Novara, Oscar; LaFuente, Jose; Large, Steve; Andes, Trent; Messick, Charles

    2000-01-01

    Aluminum-based spent nuclear fuel from Argentina's RA-3 research reactor is to be shipped to the Savannah River Site near Aiken, South Carolina, USA. The spent nuclear fuel contains highly enriched uranium of U.S. origin and is being returned under the US Department of Energy's Foreign Research Reactor/Domestic Research Reactor (FRR/DRR) Receipt Program. An intensive inspection of 207 stored fuel assemblies was conducted to assess shipping cask containment limitations and assembly handling considerations. The inspection was performed with video equipment designed for remote operation, high portability, easy setup and usage. Fuel assemblies were raised from their vertical storage tubes, inspected by remote video, and then returned to their original storage tube or transferred to an alternate location. The inspections were made with three simultaneous video systems, each with dedicated viewing, digital recording, and tele-operated control from a shielded location. All 207 fuel assemblies were safely and successfully inspected in fifteen working days. Total dose to personnel was about one-half of anticipated dose. (author)

  16. Measurements at the RA Reactor related to the VISA-2 project - Part 3, calculation of VISA-2 samples influence on the reactor reactivity, on the depression of thermal neutron flux in VK-5 channel and VISA-2 samples; Fizicka merenja na reaktoru RA u vezi projekta VISA-2 - III deo, Proracun uticaja uzoraka VISA-2 na reaktivnost reaktora, na depresiju fluksa termalnih neuntrona u kanalu VK-5 i u uzorcima VISA-2

    Energy Technology Data Exchange (ETDEWEB)

    Markovic, H; Martinc, R [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1962-07-01

    The objective of this task was to determine the thermal neutron flux in the RA reactor cell with VISA-2 samples, the influence of VISA-2 samples on the thermal neutron flux distribution in the vicinity of VK-5 channel and the antireactivity of VISA-2 samples placed in the RA reactor core. This distribution is needed for calculating the mean value of absorption and thermal efficiency factor in the reactor cell with the sample. Thermal neutron flux distribution without the sample was calculated by diffusion theory. Fast neutron flux space distribution was assumed to be constant, i.e. that it is dependent only on the nuclear properties of the materials. Macroscopic thermal neutron flux distribution was determined by two-group diffusion theory using the four factor formula applied for two regions: active RA region, and reactor region with calls containing VISA-2 samples. This calculation enables estimation of the VISA-2 samples influence on the thermal neutron flux distribution in the VK-5 channel. Antireactivity of VISA-2 samples was calculated by neutron diffusion theory applying the perturbation method. [Serbo-Croat] Cilj ovog zadatka je da se odredi raspodela fluksa termalnih neutrona u celiji reaktora RA sa uzorcima VISA-2, uticaj uzoraka VISA-2 na makroskopsku raspodelu termalnih neutrona u blizini uzoraka, tj. u kanalu VK-5, kao i antiraktivnost uzoraka VISA-2 ubacenih u jezgro RA. Poznavanje ove raspodele potrebno je za izracunavanje srednje apsorpcije i faktora termalnog iskoriscenja u celiji reaktora sa uzorkom. Raspodela fluksa termalnih neutrona u celiji RA bez uzorka izracunata je na bazi difuzione teorije. Fluks brzih neutrona uzet je kao konstanta s obzirom na prostorne koordinate, tj. da zavisi samo od nuklearnih karakteristika materijala. Makroskopska raspodela fluksa termalnih neutrona u okolini VISA-2 odredjena je na bazi dvogrupne difuzione teorije preko formule cetiri faktora, primenjene na dve zone: prva aktivna zona RA, i druga reaktorka sredina

  17. Helium diffusion in irradiated boron carbide

    International Nuclear Information System (INIS)

    Hollenberg, G.W.

    1981-03-01

    Boron carbide has been internationally adopted as the neutron absorber material in the control and safety rods of large fast breeder reactors. Its relatively large neutron capture cross section at high neutron energies provides sufficient reactivity worth with a minimum of core space. In addition, the commercial availability of boron carbide makes it attractive from a fabrication standpoint. Instrumented irradiation experiments in EBR-II have provided continuous helium release data on boron carbide at a variety of operating temperatures. Although some microstructural and compositional variations were examined in these experiments most of the boron carbide was prototypic of that used in the Fast Flux Test Facility. The density of the boron carbide pellets was approximately 92% of theoretical. The boron carbide pellets were approximately 1.0 cm in diameter and possessed average grain sizes that varied from 8 to 30 μm. Pellet centerline temperatures were continually measured during the irradiation experiments

  18. Analysis of dynamic stability and safety of reactor system by reactor simulator

    International Nuclear Information System (INIS)

    Raisic, N.

    1963-11-01

    In order to enable qualitative analysis of dynamic properties of reactors RA and RB, mathematical models of these reactors were formulated and adapted for solution on analog computer. This report contains basic assessments for creating the model and complete equations for each reactor. Model was used to analyse three possible accidents at the RA reactor and possible hypothetical accidents at the RB reactor

  19. Standard specification for boron-Based neutron absorbing material systems for use in nuclear spent fuel storage racks

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 This specification defines criteria for boron-based neutron absorbing material systems used in racks in a pool environment for storage of nuclear light water reactor (LWR) spent-fuel assemblies or disassembled components to maintain sub-criticality in the storage rack system. 1.2 Boron-based neutron absorbing material systems normally consist of metallic boron or a chemical compound containing boron (for example, boron carbide, B4C) supported by a matrix of aluminum, steel, or other materials. 1.3 In a boron-based absorber, neutron absorption occurs primarily by the boron-10 isotope that is present in natural boron to the extent of 18.3 ± 0.2 % by weight (depending upon the geological origin of the boron). Boron, enriched in boron-10 could also be used. 1.4 The materials systems described herein shall be functional – that is always be capable to maintain a B10 areal density such that subcriticality Keff <0.95 or Keff <0.98 or Keff < 1.0 depending on the design specification for the service...

  20. Analytical methods for the determination of boron in reactor materials programme

    International Nuclear Information System (INIS)

    Chitre, R.S.; Joshi, V.R.; Iyer, C.S.P.

    1983-01-01

    Spectrophotometric methods of determination of boron based on the complexation reaction between boric acid and protonated curcumin are briefly reviewed. Direct determination of boron in heavy water, plant leaves, copper and its alloys, and aluminium and its alloys using a modified method of Hayes and Metcalfe is described. A method for determination of boron, when its content is very low as in case of uranium metal, diuranate, uranium oxide and thorium nitrate, is also described. In this method, boron is first separated as methyl borate by distillation of the sample with methanol in acid media. The distilled ester is absorbed by hydroxide solution and boron is analysed after removal of methanol. The precision obtained is indicated. (M.G.B.)

  1. Identification of limiting case between DBA and SBDBA (CL break area sensitivity): A new model for the boron injection system

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Gonzalez, R., E-mail: r.gonzalez@ing.unipi.it [San Piero a Grado Nuclear Research Group (GRNSPG), University of Pisa, Via Livornese 1291, 56122 San Piero a Grado, Pisa (Italy); Petruzzi, A., E-mail: a.petruzzi@ing.unipi.it [San Piero a Grado Nuclear Research Group (GRNSPG), University of Pisa, Via Livornese 1291, 56122 San Piero a Grado, Pisa (Italy); D’Auria, F., E-mail: f.dauria@ing.unipi.it [San Piero a Grado Nuclear Research Group (GRNSPG), University of Pisa, Via Livornese 1291, 56122 San Piero a Grado, Pisa (Italy); Mazzantini, O., E-mail: mazzantini@na-sa.com.ar [Nucleo-electrica Argentina Sociedad Anonima (NA-SA), Buenos Aires (Argentina)

    2014-08-15

    Atucha-2 is a Siemens-designed Pressurized Heavy Water Reactor (PHWR) reactor under construction in the Republic of Argentina. Its geometrical complexity and peculiarity (e.g. oblique Control Rods, Positive Void coefficient) required a developed and validated complex three dimensional (3D) neutron kinetics (NK) coupled thermal hydraulic (TH) model. Reactor shut-down is obtained by oblique CRs and, during accidental conditions, by an emergency shut-down system (JDJ) injecting a highly concentrated boron solution (boron clouds) in the moderator tank. The boron clouds reconstruction is obtained using a Computational Fluid Dynamics (CFD) CFX code calculation. A complete Large Break Loss Of Coolant Accident (LBLOCA) calculation implies the application of the RELAP5-3D{sup ©} system code. Within the framework of the third Agreement “Nucleoelèctrica Argentina-Sociedad Anonima (NA-SA) – University of Pisa/GRNSPG” (Contract, 2009), a new RELAP5-3D control system for the boron injection system was developed and implemented in the validated coupled RELAP5-3D/NESTLE model of the Atucha 2 NPP. The aim of this activity is to find out the limiting case (maximum break area size) for the Peak Cladding Temperature for LOCAs under fixed boundary conditions.

  2. Communication and computer technologies for teaching physics in nuclear reactors

    International Nuclear Information System (INIS)

    Murua, C; Chautemps, A; Odetto, J; Keil, W; Trivino, S; Rossi, F; Perez Lucero, A

    2012-01-01

    In order to train personnel inn order to train personnel in Embalse Nuclear Power Plant, and provided that such training given primarily on the location of such a facility, we designed a pedagogical strategy that combined the use of conventional resources with new information technologies. Since the Nuclear Reactor RA-0 is an ideal tool for teaching Reactor Physics, priority was the use of it, both locally remotely. The teaching strategy is based on four pillar: -Lectures on the Power Plant (using a virtual classroom to support); -Remote monitoring of Ra-0 Nuclear Reactor parameters while operating (RA0REMOTO); -Use, through the Internet, of the Ra-0 Nuclear Reactor Simulator (RA0SIMUL); -Made in the Nuclear Reactor RA-0 of Reactor Physics practical. The work emphasizes RA0REMOTO and RA0SIMUL systems. The RA0REMOTO system is an appendix of the Electronic Data Acquisition System (SEAD) of the Nuclear Reactor RA-0. This system acquires signals from Reactor instrumentation and sends them to a server running the software that 'publish' the reactor parameters on the internet. Students may, during the lectures, monitor any parameter of the reactor while it operates, which allows teachers to compare theory with reality. RA0SIMUL is a simulator on the RA-0, which allows students to 'operate' a reactor analyzing the underlying physics concepts (author)

  3. Design project of the dosimetry control system in the independent CO{sub 2} loop for cooling the samples irradiated in the RA reactor vertical experimental channels, Vol. V; Album V: Predprojekat sistema dozimetrijske kontrole u nezavisnom kolu CO{sub 2} za hladjenje uzoraka ozracivanih u VEK reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1964-07-01

    Design project of the dosimetry control system in the independent CO{sub 2} loop for cooling the samples irradiated in the RA reactor vertical experimental channels includes the following: calculations of CO{sub 2} gas activity, design of the dosimetry control system, review of the changes that should be done in the RA reactor building for installing the independent CO{sub 2} loop, specification of the materials with cost estimation, engineering drawings of the system. Predprojekat sistema dozimetrijske kontrole u nezavisnom kolu CO{sub 2} za hladjenje uzoraka ozracivanih u vertikalnim eksperimentalnim kanalima reaktora RA sadrzi: proracun aktivnosti gasa CO{sub 2}, idejno resenje sistema dozimetrijske kontrole, pregled izmena koje bi trebalo izvrsiti u zgradi RA u vezi montaze nezavisnog kola CO{sub 2}, specifikaciju materijala sa cenom kostanja i graficku dokumentaciju predprojekta.

  4. Ra reactor operation plan for 1976 - Annex 6; Prilog 6 - Plan rada reaktora RA za 1976. godinu

    Energy Technology Data Exchange (ETDEWEB)

    Martinc, R [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1976-01-15

    Contrary to previous years the RA reactor operation plan for 1976 is conditioned by more uncertainties than ever for the following reasons. It is planned for February to repair the components in order to eliminate the consequences of leaking from the vertical experimental channel VK-4 which happened in december 1975. Apart from this, measurements related to transfer of the core to highly enriched fuel under minimum power are foreseen to be performed in February. In April, it would be indispensable to locate the point of He gas leaking and its prevention. Core transfer to highly enriched fuel is planned for April for testing of the fuel elements under operating conditions and step by step increase of the power density up to the nominal power. Complete plan for core transfer would be available by the end of February 1976. It is planned to make-up for the mentioned delays from May-December 1976. [Serbo-Croat] Za razliku od prethodnih godina izrada plana rada reaktora RA za 1976. godinu vezana je za mnogo vise neizvesnosti nego ikada ranije iz sledecih razloga. U februaru se vrsi remont opreme i uklanjanja posledica procurivanja vertikalnog eksperimentalog kanala VK-4, koje se dogodilo decembra 1975. Sem toga u februaru se vrse merenja na minimalnim snagama u sklopu priprema za prelazak na novo gorivo. U aprilu ce biti neophodno lociranje mesta gde istice He gas kao i otklanjanje uzroka ovog curenja. Planirano je da se u aprilu ubaci novo gorivo u jezgro u cilju testiranja pod radnim uslovima uz postepeno povecanje snage do nominalne. Planirano je da se smanjeni obim rada usled navedenih uslova nadoknadi u potpunosti u periodu maj-decembar 1976.

  5. A fast-running core prediction model based on neural networks for load-following operations in a soluble boron-free reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jin-wook [Korea Atomic Energy Research Institute, P.O. Box 105, Yusong, Daejon 305-600 (Korea, Republic of)], E-mail: Jinwook@kaeri.re.kr; Seong, Seung-Hwan [Korea Atomic Energy Research Institute, P.O. Box 105, Yusong, Daejon 305-600 (Korea, Republic of)], E-mail: shseong@kaeri.re.kr; Lee, Un-Chul [Department of Nuclear Engineering, Seoul National University, Shinlim-Dong, Gwanak-Gu, Seoul 151-742 (Korea, Republic of)

    2007-09-15

    A fast prediction model for load-following operations in a soluble boron-free reactor has been proposed, which can predict the core status when three or more control rod groups are moved at a time. This prediction model consists of two multilayer feedforward neural network models to retrieve the axial offset and the reactivity, and compensation models to compensate for the reactivity and axial offset arising from the xenon transient. The neural network training data were generated by taking various overlaps among the control rod groups into consideration for training the neural network models, and the accuracy of the constructed neural network models was verified. Validation results of predicting load following operations for a soluble boron-free reactor show that this model has a good capability to predict the positions of the control rods for sustaining the criticality of a core during load-following operations to ensure that the tolerable axial offset band is not exceeded and it can provide enough corresponding time for the operators to take the necessary actions to prevent a deviation from the tolerable operating band.

  6. A fast-running core prediction model based on neural networks for load-following operations in a soluble boron-free reactor

    International Nuclear Information System (INIS)

    Jang, Jin-wook; Seong, Seung-Hwan; Lee, Un-Chul

    2007-01-01

    A fast prediction model for load-following operations in a soluble boron-free reactor has been proposed, which can predict the core status when three or more control rod groups are moved at a time. This prediction model consists of two multilayer feedforward neural network models to retrieve the axial offset and the reactivity, and compensation models to compensate for the reactivity and axial offset arising from the xenon transient. The neural network training data were generated by taking various overlaps among the control rod groups into consideration for training the neural network models, and the accuracy of the constructed neural network models was verified. Validation results of predicting load following operations for a soluble boron-free reactor show that this model has a good capability to predict the positions of the control rods for sustaining the criticality of a core during load-following operations to ensure that the tolerable axial offset band is not exceeded and it can provide enough corresponding time for the operators to take the necessary actions to prevent a deviation from the tolerable operating band

  7. Boron isotopic enrichment by displacement chromatography

    International Nuclear Information System (INIS)

    Mohapatra, K.K.; Bose, Arun

    2014-01-01

    10 B enriched boron is used in applications requiring high volumetric neutron absorption (absorption cross section- 3837 barn for thermal and 1 barn for 1 MeV fast neutron). It is used in fast breeder reactor (as control rod material), in neutron counter, in Boron Neutron Capture Therapy etc. Owing to very small separation factor, boron isotopic enrichment is a complex process requiring large number of separation stages. Heavy Water Board has ventured in industrial scale production of 10 B enriched boron using Exchange Distillation Process as well as Ion Displacement Chromatography Process. Ion Displacement Chromatography process is used in Boron Enrichment Plant at HWP, Manuguru. It is based on isotopic exchange between borate ions (B(OH) 4 - ) on anion exchange resin and boric acid passing through resin. The isotopic exchange takes place due to difference in zero point energy of 10 B and 11 B

  8. Neutron physical investigations on the shutdown effect of small boronated absorbing spheres for pebble-bed high-temperature gas-cooled reactors

    International Nuclear Information System (INIS)

    Sgouridis, S.; Schurrer, F.; Muller, H.; Ninaus, W.; Oswald, K.; Neef, R.D.; Schaal, H.

    1987-01-01

    An emergency shutdown system for high-temperature gas-cooled pebble-bed reactors is proposed in addition to the common absorber rod shutdown system. This system is based on the strongly absorbing effect of small boronated graphite spheres (called KLAK), which trickle in case of emergency by gravity from the top reflector into the reactor core. The inner reflector of the Siemens-Argonaut reactor was substituted by an assembly of spherical Arbeitsgemeinschaft Versuchsreaktor fuel elements, and the shutdown effect was examined by installing well-defined KLAK nests inside this assembly. The purpose was to develop and prove a calculational procedure for determining criticality values for assemblies of large fuel spheres and small absorbing spheres

  9. Correlation for boron carbide helium release in fast reactors

    International Nuclear Information System (INIS)

    Basmajian, J.A.; Pitner, A.L.

    1977-04-01

    An empirical helium correlation for the helium release from boron carbide has been developed. The correlation provides a good fit to the experimental data in the temperature range from 800 to 1350 0 K, and burnup levels up to 80 x 10 20 captures/cm 3 . The correlation has the capability of extrapolation to 2200 0 K (3500 0 F) and 200 x 10 20 captures/cm 3 . In this range the helium release rate will not exceed the generation rate

  10. Thermal hydraulic modelling of the Mo and Iridium irradiation facilities of the RA10 reactor

    International Nuclear Information System (INIS)

    Gramajo, M.; García, J.; Marcel, C.P.

    2013-01-01

    The RA-10 reactor is a multipurpose, open pool research reactor. The core consists of a rectangular array of MTR type fuel. The produced thermal power is 30 MW which is extracted by the refrigeration system via an ascendant flow through the core. The core reflector is D 2 O contained in a watertight tank. The design of the reactor includes a number of out-core facilities which are meant to be used for industrial, medical and research purposes. Among all the facilities, the most important ones are the Molybdenum and Iridium ones which we modeled in this work. During the normal operation of the reactor, the manipulation and the on-line extraction of the irradiation facilities is foreseen. Therefore the study of the head loss during the normal operation as well as during the extraction maneuvers plays a relevant role in the design and safety analysis. In this work a CFD commercial code is use dto perform the calculations needed to guarantee the design requirements.In addition, a full detailed geometric model for both, the Molybdenum and Iridium facilities,is used to perform the required simulations. The obtained results allow to evaluating the thermal-hydraulic performance of the proposed facilities designs. (author)

  11. Dosimetry and radiation protection at the RA reactor in 1972; Dozimetrija i zastita kod reaktora RA u 1972. godini

    Energy Technology Data Exchange (ETDEWEB)

    Ninkovic, M M [Institute of nuclear sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

    1973-07-01

    Dosimetry results collected within radiation protection of the RA reactor during this year are presented. Neutron and gamma radiation data were measured at characteristic control points. Statistical review of the total number of measurement is given as well. The report includes contents of radioactive gasses and aerosols in the air, as well as the contamination data of surfaces, clothes and uncovered body parts of the personnel. Particular accident which occurred during dismantling of the experimental channel containing the capsule with the new fuel element was analysed. This accident occurred at the RA reactor at the beginning of this year. It was found that that the maximum individual external dose was 2.2 R, and that only one individual was exposed to this dose. About 15% of the personnel was exposed to doses between 1 and 2 R, the remaining 85% was exposed to doses less than 1 R. Base on the frequency of activities undertaken in the contaminated regions, safety and control measures and expected internal exposure of the personnel, it was evaluated that the internal exposure could be neglected compared to the external exposure of the personnel. Prikazani su rezultati sakupljani u toku godine u okviru dozimetrijske kontrole i zastite kod reaktora. Dati su podaci o nivoima neutrona i gama zracenja na karakteristicnim kontrolnim mestima, kao i statisticki pregledi ukupnog broja merenja. Navedeni su rezultati merenja sadrzaja radioaktivnih gasova i aerosola u vazduhu, kao i stepena kontaminacije povrsina, odece i otkrivenih delova tela radnog osoblja. Analiziran je specifican akcident koji se odigrao na reaktoru pocetkom godine, pri demontazi eksperimentalnog kanala sa kapsulom novog gorivog elementa. Na kraju, izlozena je analiza ozracivanja radnog osoblja. Konstatovano je da je maksimalna individualna doza spoljasnjeg ozracivanja bila 2,2 (R), i da je ovoj dozi bilo izlozeno samo jedno lice. Oko 15% osoblja bilo je izlozeno dozama izmedju 1 i 2 (R), a ostalih 85

  12. Preparation of a criticality benchmark based on experiments performed at the RA-6 reactor

    International Nuclear Information System (INIS)

    Bazzana, S.; Blaumann, H; Marquez Damian, J.I

    2009-01-01

    The operation and fuel management of a reactor uses neutronic modeling to predict its behavior in operational and accidental conditions. This modeling uses computational tools and nuclear data that must be contrasted against benchmark experiments to ensure its accuracy. These benchmarks have to be simple enough to be possible to model with the desired computer code and have quantified and bound uncertainties. The start-up of the RA-6 reactor, final stage of the conversion and renewal project, allowed us to obtain experimental results with fresh fuel. In this condition the material composition of the fuel elements is precisely known, which contributes to a more precise modeling of the critical condition. These experimental results are useful to evaluate the precision of the models used to design the core, based on U 3 Si 2 and cadmium wires as burnable poisons, for which no data was previously available. The analysis of this information can be used to validate models for the analysis of similar configurations, which is necessary to follow the operational history of the reactor and perform fuel management. The analysis of the results and the generation of the model were done following the methodology established by International Criticality Safety Benchmark Evaluation Project, which gathers and analyzes experimental data for critical systems. The results were very satisfactory resulting on a value for the multiplication factor of the model of 1.0000 ± 0.0044, and a calculated value of 0.9980 ± 0.0001 using MCNP 5 and ENDF/B-VI. The utilization of as-built dimensions and compositions, and the sensitivity analysis allowed us to review the design calculations and analyze their precision, accuracy and error compensation. [es

  13. New ceramics for nuclear industry. Case of fission and fusion reactors

    International Nuclear Information System (INIS)

    Yvars, M.

    1979-10-01

    The ceramics used in the nuclear field are described as is their behaviour under radiation. 1) Power reactors - nuclear fission. Ceramics enter into the fabrication of nuclear fuels: oxides, carbides, uranium or plutonium nitrides or oxy-nitrides. Silicon carbide SiC is used for preparing the fuels of helium cooled high temperature reactors. Its use is foreseen in the design of gas high temperature gas thermal exchangers, as is silicon nitride (Si 3 N 4 ). In the materials for safety or control rods, the intense neutron flows induce nuclear reactions which increase the temperature of the neutron absorbing material. Boron carbide B 4 C, rare earth oxides Ln 2 O 3 , or B 4 C-Cu or B 4 C-Al cermets are employed. Burnable poison materials are formed of Al 2 O 3 -B 4 C or Al 2 O 3 -Ln 2 O 3 cermets. The moderators of thermal neutron reactors are in high purety polycrystalline graphite. For the thermal insulation of reactor vessels and jackets, honeycomb ceramics are used as well as ceramic fibres on an increasing scale (kaolin, alumina and other fibres). 2) fusion reactors (Tokomak). These require refractory materials with a low atomic number. Carbon fibres, boron carbide, some borons (Al B 12 ), silicon nitrides and oxy-nitrides and high density alumina are the substances considered [fr

  14. Compatibility of heat resistant alloys with boron carbide, 5

    International Nuclear Information System (INIS)

    Baba, Shinichi; Kurasawa, Toshimasa; Endow, Taichi; Someya, Hiroyuki; Tanaka, Isao.

    1986-08-01

    This paper includes an experimental result of out-of-pile compatibility and capsule design for irradiation test in Japan Materials Testing Reactor (JMTR). The compatibility between sheath material and neutron absorber materials for control rod devices (CRD) was examined for potential use in a very high temperature reactor (VHTR) which is under development at JAERI. The purpose of the compatibility tests are preliminary evaluation of safety prior to irradiation tests. Preliminary compatibility evaluation was concerned with three items as follows : 1) Lithium effects on the penetrating reaction of Incoloy 800H alloy in contact with a mixture of boronated graphite and lithium hydroxide powders, 2) Short term tensile properties of Incoloy 800H and Hastelloy XR alloy reacted with boronated graphite and fracture mode analysis, 3) Reaction behavior of both alloys under transient power conditions of a VHTR. It was clear that the reaction rate constant of the Incoloy 800H alloy was accelerated by doping lithium hydroxide into the boron carbide and graphite powder. The mechanical properties of Incoloy 800H and Hastelloy XR alloy reacted with boronated graphite were decreased. Ultimate tensile strength and tensile ductilities at temperatures over 850 deg C were reduced, but there was no change in the proof (yield) stress. Both alloys exhibited a brittle intergranular fracture mode during transient power conditions of a VHTR and also exhibited severe penetration. Irradiation capsules for compatibility test were designed to simulate three irradiation conditions of VHTR: 1) steady state for VHTR, 2) Transient power condition, 3) Service limited life of CRD. Capsule irradiation experiments have been carried out satisfactorily and thus confirm the validity of the capsule design procedure. (author)

  15. RA Research reactor, Annual report 1972; Istrazivacki nuklearni reaktor RA - Izvestaj za 1972. godinu - Pogon i odrzavanje

    Energy Technology Data Exchange (ETDEWEB)

    Milosevic, D et al. [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1972-12-15

    During 1972, the total production was 31151 MWh which is 3.8% higher than planned. The reactor was used for irradiation and experiments according to the demand of 381 users, of which 340 from the Institute and 41 external users. This report contains detailed data about reactor power and experiments performed in 1972. Discrepancies from the action plan, meaning higher production was achieved due to special demands of the users. Total number of interruptions was lower than during all the previous years, and were caused mainly due to announced power cuts. There was only on scram shutdown during this year caused by a false signal of the reactor control instrumentation. There were no longer interruptions. One shorter interruption (shorter than 24 hours) caused by removal of a UO{sub 2} capsule from the core, placed there for measuring heat transfer. Total personnel exposure dose was lower than during previous years. One accident caused contamination with gases and aerosols containing mainly shot-living isotopes. Decontamination od surfaces was less than during previous years. Practically there was no surface contamination that would demand action of the decontamination team, except for the regular decontamination after refueling. It was concluded that the successful operation in 1972 has a special significance having taking in account the financial crisis caused by the unresolved status of the reactor. It is emphasised, in the plan for the next year that there is an urgent need of making a long-term plan of rector application. It is indispensable to finish preparatory tasks for replacing the fuel with the highly enriched fuel elements by 1974, and building the core emergency cooling system. [Serbo-Croat] Ukupni rad Reaktora RA je u 1972. godini iznosio je 31151 MWh odnosno 3,8% vise od planiranog. Reaktor je koriscen za ozracivanja i eksperimente za 381 korisnika od cega 340 iz Instituta i 41 za korisnike izvan Instituta. Ovaj izvestaj sadrzi detaljne podatke o radu i

  16. External irradiation of the personnel operating the reactor RA at Vinca in the period 1963-1966; Spoljasnje ozracivanje osoblja koje opsluzuje reaktor RA u Vinci u periodu 1963-1966

    Energy Technology Data Exchange (ETDEWEB)

    Ninkovic, M M; Minincic, Z [Institut za nuklearne nauke Vinca, Belgrade (Yugoslavia)

    1967-07-01

    The objective of this paper was the analysis of external radiation exposure of the personnel employed at the RA reactor in Vinca during past four years. During 1963 reactor was not operated because of the general repair and maintenance, and it was operated during 1964, 1965 and 1966. The internal irradiation and the estimation of the beta doses on the skin were not analysed in this paper, they should be treated by separate analyses. The evaluation of external irradiation covered only gamma radiation since yhe neutron doses were negligible. The analysis was based on the the irradiation dose data obtained by film and personal dosemeters. Predmet ovog rada je analiza spoljasnjeg ozracivanja osoblja koje je radilo na reaktoru RA u Vinci u poslednje cetiri godine, u toku kojih je reaktor bio u opstem remontu 1963, odnosno u normalnom radu 1964, 1965 i 1966. U ovom radu nismo se upustali u analizu unutrasnjeg ozracivanja, kao ni procenu doza beta zracenja na kozi, sto treba da bude predmet posebnih analiza. Pri proceni spoljasnjeg ozracivanja operisano je samo sa dozama gama zracenja, jer je ozracivanje neutronima zanemarljivo. Celokupna analiza izvrsena je na osnovu podataka o dozama ozracivanja do kojih se doslo ocitavanjem film o penkalo dozimetara.

  17. Primary Coolant pH Control for Soluble Boron-Free PWRs

    International Nuclear Information System (INIS)

    Cheon, Yang Ho; Lee, Nam Yeong; Park, Byeong Ho; Park, Seong Chan; Kim, Eun Kee

    2015-01-01

    These should be considered when evaluating and designing the operating pH program for nuclear power plants. This paper discusses the advanced water chemistry strategies to keep pace with the recent global trends related to pH control in the primary water system for soluble boron pressurized water reactor (PWR) plants. Finally, the objective of this work is to study primary coolant pH control for soluble boron-free PWR plants. This paper reviewed the advanced water chemistry strategies to keep pace with the recent global trends related to pH control in the primary water chemistry system for soluble boron PWR plants. The new chemistry trend for the primary coolant is towards adaption of the constant and elevated chemistry. Finally, this work studied primary coolant pH control for soluble boron-free PWR plants. The ammonia-based water chemistry related to pH control for boron-free PWR plants was discussed. The ammonia-based water chemistry is not recommended to avoid fluctuation of the pH value by ammonia radiolysis and to reduce C-14 production in reactor coolant from reaction with dissolved nitrogen. Also, the potassium-based water chemistry related to pH control for boron-free PWR plants was discussed. KOH has a potential as an alternative pH control agent for soluble boron-free PWR plants. The potassium-based water chemistry related to pH control is recommended for boron-free operation as follows

  18. A model for the description of the coolant mixing and its application to the analysis of boron dilution transients in pressurized water reactors; Ein Modell zur Beschreibung der Kuehlmittelvermischung und seine Anwendung auf die Analyse von Borverduennungstransienten in Druckwasserreaktoren

    Energy Technology Data Exchange (ETDEWEB)

    Kliem, Soeren

    2010-08-15

    A model for the realistic description of the coolant mixing inside the pressure vessel of a pressurized water reactors has been developed and validated. This fast running model is based on the linear superposition of response functions on Dirac-pulse-like perturbations of the coolant parameters. It has been implemented into the coupled code system DYN3D/ATHLET nad serves as the interface between the one-dimensional thermal hydraulic system code ATHLETE and the 3D neutron kinetic core model DYN3D. By help of this model, the coolant mixing inside the reactor pressure vessel can e simulated in an efficient manner. A methodology for this analysis of hypothetical boron dilution accidents has been developed, which is based on the newly developed model for the coolant mixing. This methodology consists of a combination of stationary and transient calculations including a realistic treatment of the mixing of deborated slugs on the way towards the reactor core. The degree of conservatism can be adjusted by the variation of the initial size of the deborated slug. This new method was applied to two different boron dilution accidents. Besides the start of the first main coolant pump with a deborated slug of coolant in the cold leg of the primary circuit, a deboration event during the operation of the residual heat removal system was investigated. The results of the parameter study for a reactor core with a generic loading pattern demonstrated in both cases, that although the shut-down reactor becomes re-critical safety relevant cladding temperature limits are not reached, even if maximum possible volumes of the deborated slug are considered. The main reason for these results is the use of realistic time-dependent distributions of the boron concentration at the inlet of each fuel assembly.

  19. Quantitative analysis of boron by neutron radiography

    International Nuclear Information System (INIS)

    Bayuelken, A.; Boeck, H.; Schachner, H.; Buchberger, T.

    1990-01-01

    The quantitative determination of boron in ores is a long process with chemical analysis techniques. As nuclear techniques like X-ray fluorescence and activation analysis are not applicable for boron, only the neutron radiography technique, using the high neutron absorption cross section of this element, can be applied for quantitative determinations. This paper describes preliminary tests and calibration experiments carried out at a 250 kW TRIGA reactor. (orig.) [de

  20. RA Research reactor, Annual report 1972

    International Nuclear Information System (INIS)

    Milosevic, D. et al.

    1972-12-01

    During 1972, the total production was 31151 MWh which is 3.8% higher than planned. The reactor was used for irradiation and experiments according to the demand of 381 users, of which 340 from the Institute and 41 external users. This report contains detailed data about reactor power and experiments performed in 1972. Discrepancies from the action plan, meaning higher production was achieved due to special demands of the users. Total number of interruptions was lower than during all the previous years, and were caused mainly due to announced power cuts. There was only on scram shutdown during this year caused by a false signal of the reactor control instrumentation. There were no longer interruptions. One shorter interruption (shorter than 24 hours) caused by removal of a UO 2 capsule from the core, placed there for measuring heat transfer. Total personnel exposure dose was lower than during previous years. One accident caused contamination with gases and aerosols containing mainly shot-living isotopes. Decontamination od surfaces was less than during previous years. Practically there was no surface contamination that would demand action of the decontamination team, except for the regular decontamination after refueling. It was concluded that the successful operation in 1972 has a special significance having taking in account the financial crisis caused by the unresolved status of the reactor. It is emphasised, in the plan for the next year that there is an urgent need of making a long-term plan of rector application. It is indispensable to finish preparatory tasks for replacing the fuel with the highly enriched fuel elements by 1974, and building the core emergency cooling system [sr

  1. Radiation shielding properties of high performance concrete reinforced with basalt fibers infused with natural and enriched boron

    Energy Technology Data Exchange (ETDEWEB)

    Zorla, Eyüp; Ipbüker, Cagatay [University of Tartu, Institute of Physics (Estonia); Biland, Alex [US Basalt Corp., Houston (United States); Kiisk, Madis [University of Tartu, Institute of Physics (Estonia); Kovaljov, Sergei [OÜ Basaltest, Tartu (Estonia); Tkaczyk, Alan H. [University of Tartu, Institute of Physics (Estonia); Gulik, Volodymyr, E-mail: volodymyr.gulik@gmail.com [Institute for Safety Problems of Nuclear Power Plants, Lysogirska 12, of. 201, 03028 Kyiv (Ukraine)

    2017-03-15

    Highlights: • Basalt fiber infused with natural and enriched boron in varying proportions. • Gamma-ray attenuation remains stable with addition of basalt-boron fiber. • Improvement in neutron shielding for nuclear facilities producing fast fission spectrum. • Basalt-boron fiber could decrease the shielding thickness in thermal spectrum reactors. - Abstract: The importance of radiation shielding is increasing in parallel with the expansion of the application areas of nuclear technologies. This study investigates the radiation shielding properties of two types of high strength concrete reinforced with basalt fibers infused with 12–20% boron oxide, containing varying fractions of natural and enriched boron. The gamma-ray shielding characteristics are analyzed with the help of the WinXCom, whereas the neutron shielding characteristics are modeled and computed by Monte Carlo Serpent code. For gamma-ray shielding, the attenuation coefficients of the studied samples do not display any significant variation due to the addition of basalt-boron fibers at any mixing proportion. For neutron shielding, the addition of basalt-boron fiber has negligible effects in the case of very fast neutrons (14 MeV), but it could considerably improve the neutron shielding of concrete for nuclear facilities producing a fast fission spectrum (e.g. with reactors as BN-800, FBTR) and thermal neutron spectrum (Light Water Reactors (LWR)). It was also found that basalt-boron fiber could decrease the thickness of radiation shielding material in thermal spectrum reactors.

  2. Radiation shielding properties of high performance concrete reinforced with basalt fibers infused with natural and enriched boron

    International Nuclear Information System (INIS)

    Zorla, Eyüp; Ipbüker, Cagatay; Biland, Alex; Kiisk, Madis; Kovaljov, Sergei; Tkaczyk, Alan H.; Gulik, Volodymyr

    2017-01-01

    Highlights: • Basalt fiber infused with natural and enriched boron in varying proportions. • Gamma-ray attenuation remains stable with addition of basalt-boron fiber. • Improvement in neutron shielding for nuclear facilities producing fast fission spectrum. • Basalt-boron fiber could decrease the shielding thickness in thermal spectrum reactors. - Abstract: The importance of radiation shielding is increasing in parallel with the expansion of the application areas of nuclear technologies. This study investigates the radiation shielding properties of two types of high strength concrete reinforced with basalt fibers infused with 12–20% boron oxide, containing varying fractions of natural and enriched boron. The gamma-ray shielding characteristics are analyzed with the help of the WinXCom, whereas the neutron shielding characteristics are modeled and computed by Monte Carlo Serpent code. For gamma-ray shielding, the attenuation coefficients of the studied samples do not display any significant variation due to the addition of basalt-boron fibers at any mixing proportion. For neutron shielding, the addition of basalt-boron fiber has negligible effects in the case of very fast neutrons (14 MeV), but it could considerably improve the neutron shielding of concrete for nuclear facilities producing a fast fission spectrum (e.g. with reactors as BN-800, FBTR) and thermal neutron spectrum (Light Water Reactors (LWR)). It was also found that basalt-boron fiber could decrease the thickness of radiation shielding material in thermal spectrum reactors.

  3. Hydrotreating of heavy gas oil derived from Athabasca bitumen using NiMo/Al2O3 catalyst containing boron and phosphorus : effects of process conditions on the product selectivity

    Energy Technology Data Exchange (ETDEWEB)

    Ferdous, D.; Dalai, A.K. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Chemistry and Chemical Engineering; Adjaye, J. [Syncrude Canada Ltd., Edmonton, AB (Canada). Edmonton Research Centre

    2004-07-01

    In response to concerns regarding the depletion of conventional oil reserves, there has been much interest in modifying the hydrotreating process for upgrading tar sands and shale oils for producing transportation fuels. Oil sand bitumens and their derived products have a high level of nitrogen which deactivates the catalysts used in fluid catalytic cracking and hydrocracking. A better catalyst is needed to efficiently remove nitrogen from oil sand-derived gas oils. In this study, a trickle-bed reactor containing NiMo/Al{sub 2}O{sub 3} catalysts with boron and phosphorous was used to remove the sulfur and nitrogen from heavy gas oils derived from Athabasca bitumen. The operating conditions of the reactor in terms of temperature and pressure were described. Sulfur and nitrogen conversion was found to increase substantially with the boron catalysts. Gasoline selectivity also increased with an increase in temperature. However, a change in operating conditions did not significantly affect the net content of the gas oil fraction. This study also compared the results of using either the boron or phosphorous catalyst.

  4. Thermohydraulic calculations in rectangular channels for RA-6 type reactors with transition regime

    International Nuclear Information System (INIS)

    Sillin, N; Vertullo, A.; Masson, V.; Hilal, R

    2009-01-01

    In August 2000 and within the framework of the RA-6 core conversion from high to low enrichment (20%), a preliminary analysis was performed to evaluate the maximum power that the reactor could operate with the new kernel without makeing substantial changes. This meant keeping intact, for example, the concrete shield of the pool and the nucleus inlet and outlet pipes embedded in the walls. Preliminary results indicated that for these boundary conditions a maximum power of about 3 MWt could be achieved. In August 2005 the project was resumed and new calculations performed taking as a starting point the ECBE plate fuel element(U3O8-Al). A core was developed with cooling channle widths of 2.6 mm for the control fuel elements and 2.7 mm for standard fuel elements. The thermo-hydraulic calculation puts in evidence that coolant flow into the core was in the transitional regime for the vast majority of configurations. While TERMIC code, used for thermo-hydraulic design, has been extensively tested and validated for use in research reactors under turbulent and laminar flows, this is not so for transition conditions. The transition regime is strongly dependent on conditions such as flow inlet characteristics, channel geometry, etc.. and therefore there are no reliable correlations for general use. For this reason we found it convenient to carry out experiments simulating the working conditions in order to adjust the code results with experimental data. In the present work we show the experimental results, the simulation of the experiences using the TERMIC code, and the adjustments made to the correlations used by the code so that it can be applied to the thermo-hydraulic design of the new core. [es

  5. Operation and maintenance of the RA nuclear reactor for 1977, Report Annex I; Rad i iskoriscenost reaktora RA u 1977. godini, izvestaj Prilog I

    Energy Technology Data Exchange (ETDEWEB)

    Martinc, R; Stanic, A [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1977-12-15

    RA reactor operation plan was fulfilled, meaning 28583 MWh. In addition to 183 days of operation at full power, during 1977 the reactor was operated for 14 days at lower power level according to the demand of users. The utilization level of rector irradiation capability (neutron flux and time of operation) was 14%. This annex includes detailed statistical data about reactor operation, utilization, power level, savings concerned with new 80% enriched fuel. All the 9 vertical experimental channels were used for irradiation in the reactor core. Digression from the action plan were caused by refueling and demand od the users. There have been 11 safety shutdowns, of which 6 caused by power cuts, 4 due to failure of the instruments, and 1 due to earthquake in March 1977. [Serbo-Croat] Planirani rad reaktora na nominalnoj snazi ostvaren je u iznosu od 28583 MWh. U toku 1977. godine reaktor je radio 14 dana na manjim snagama i u posebnom eksperimentalnom rezimu na zahtev korisnika. Iskoriscenost kapaciteta reaktora za ozracivanje uzoraka (na bazi neutronskog fluksa i vremena rada reaktora) bila je 41%. Ovaj izvestaj sadrzi detaljne statisticke podatke o radu i iskoriscenosti reaktora, podatke o ustedi goriva prelaskom na 80% obogaceno gorivo. Korisceno je svih 9 vertikalnih eksperimentalnih kanala u aktivnoj zoni. Uzroci odstupanja od plana rada osim zamene goriva bili su zahtevi korisnika. Bilo je 11 sigurnosnih zaustavljanja, 6 usled nestanka napona, 4 usled kvarova opreme i instrumentacije, i 1 put usled zemljotresa u martu.

  6. Reactor oscillator - I - III, Part I

    International Nuclear Information System (INIS)

    Lolic, B.

    1961-12-01

    Project 'Reactor oscillator' covers the following activities: designing reactor oscillators for reactors RA and RB with detailed engineering drawings; constructing and mounting of the oscillator; designing and constructing the appropriate electronic equipment for the oscillator; measurements at the RA and RB reactors needed for completing the oscillator construction

  7. Ionic conductivity in BC3 type boron carbon nanolayers

    Directory of Open Access Journals (Sweden)

    Irina V. Zaporotskova

    2017-06-01

    Full Text Available Studies of ionic conductivity and structuresf in which it can be achieved are of great importance for the development of modern batteries. The use of new materials will allow avoiding such typical disadvantages of batteries as short service life, low capacity and leaks. In this article we present the results of our study of the ionic conductivity in boron carbon nanolayers. We have simulated three types of boron carbon nanolayers containing different amounts of boron. The studies have been carried out using the MNDO method within the framework of the molecular cluster model and the DFT method with the B3LYP functional and the 6–31G basis. To study the ion conduction process we have simulated vacancy formation for each type of the nanolayers and studied the energy and electronic characteristics of these processes. We show that 25% boron substitution is the most energetically favorable for vacancy formation. We have also simulated vacancy migration and determined the thermal conductivity as a function of temperature.

  8. Neutron magnetic scattering experiments performed by VIKRA group at the RA reactor in Vinca; Eksperimenti grupe VIKRA na reaktoru RA u Vinci sa rasejanjem neutrona na magnetnim materijalima

    Energy Technology Data Exchange (ETDEWEB)

    Kranicki, S; Rzany, H; Wanic, A [Institute of Nuclear Physics, Krakov (Poland); Szytula, A [Jagiellonian University, Krakov (Poland); Todorovic, J; Dimitrijevic, Z; Radenkovic, S [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

    1978-05-15

    A short communication about investigations of magnetic materials by means of the neutron magnetic scattering performed by Polish-Yugoslav group VIKRA (Vinca-Krakov) at the RA reactor in Vinca in the period 1962-1977 will be presented. In the field of neutron inelastic scattering information about magnetic interactions (exchange integrals) and their temperature behaviour in such substances as Fe{sub 7}S{sub 8}, {alpha}-Fe{sub 2}O{sub 3}, CR{sub 2}O{sub 3}, {alpha}-Co, Cu{sub 2}MnAl and Mn{sub 1.88}Cr{sub 0.12}Sb was obtained by measuring magnon dispersion relations. In the field of neutron elastic scattering valuable results concerning crystallographic and magnetic structures of oxyhydroxides, several Heusler alloys and intermetallic compounds of 3d metals (for instance of NiMnGe, CoMnSi) were obtained. A short description of the KSN spectrometer used in all experiments will also be given. (author) Dato je kratko saopstenje o istrazivanjima magnetnih materijala magnetnim neutronskim rasejanjem izvrsenim od strane poljsko-jugoslovenske grupe VIKRA (Vinca-Krakov) na reaktoru RA u Vinci u periodu od 1962-1977. U oblasti neelasticnog rasejanja neutrona, obavestenja o magnetnim uzajamnim dejstvima (integralima izmene) i njihovim temperaturskim ponasanjima su dobijeni merenjem disperzione relacije magnona u takvim materijalima kao sto su Fe{sub 7}S{sub 8}, {alpha}-Fe{sub 2}O{sub 3}, CR{sub 2}O{sub 3}, {alpha}-Co, Cu{sub 2}MnAl and Mn{sub 1.88}Cr{sub 0.12}Sb. U oblasti neutronskog elasticnog rasejanja dobijeni su korisni rezultati o kristalografskim i magnetnim strukturama oksihidroksida gvozdja, niza Heuslerovih legura i intermetalnih jedinjenja 3d metala (napr. NiMnGe, Co,MnSi). Dat je kratak opis KSN spektrometra upotrebljenog u svim ovim eksperimentima. (author)

  9. Establishment of the observing system for boron in steels by alpha-particle track etching method using JAERI reactor

    International Nuclear Information System (INIS)

    Asakura, Kentaro; Shibata, Koji; Sawahata, Hiroyuki; Kawate, Minoru; Harasawa, Susumu

    2003-01-01

    Alpha-particle track etching (ATE) method is most effective in observing boron distribution in steels. Previously, in Japan, neutron irradiation for this method was carried out in the reactor at the Institute of Atomic Energy, Rikkyo University. This reactor, however, was shut down in 1999. Therefore, the establishment of a new system for ATE method has been required and experimental research was performed using the reactor at the Japan Atomic Energy Research Institute (JAERI). It was clarified that the irradiation equipment for medical treatment of the reactor JRR-4 was most suitable for ATE method. The specimen trestle for low radioactive exposure was newly-developed. ATE image obtained by 12h irradiation using this trestle showed a good quality similar to that obtained using Rikkyo's reactor and that obtained using the trestle of the old model. Using this new trestle, the amount of neutron which the worker suffers during the operation at the irradiation equipment decreases from 4μSv/h to 0-1 μSv/h compared with the trestle of the old model. The total amount of thermal neutron after 12 h irradiation was almost same as that under the recommended condition of the reactor at Rikkyo University, 6.5 x 10 14 n cm -2 . (author)

  10. An overview the boron dilution issue in PWRs

    International Nuclear Information System (INIS)

    Hyvaerinen, J.

    1994-01-01

    The presentation is an overview of boron (boric acid) dilution in pressurized water reactors (PWRs). Boric acid has been widely used in PWRs as a dissolved poison, as one of the main reactivity controlling means, for a long time, from nearly but not quite from the beginning of the design, construction and operation of PWRs in the present-day sense. The specific safety issue, namely the risk of uncontrolled reactivity insertion due to inadvertent boron dilution, is discussed first, followed by a brief look on the history of boron usage in PWRs. A discussion of boron dilution phenomenology is presented next in general terms. Some particular concerns that boron dilution phenomena arouse in the minds of a regulator will also be presented before concluding with a brief look on the future of dissolved poisons. (11 refs.)

  11. Shoot and root responses of Trifolium vesiculosum to boron fertilization in an acidic Brazilian soil

    Directory of Open Access Journals (Sweden)

    Nerilde Favaretto

    2007-07-01

    Full Text Available To analyze the influence of boron fertilization on shoot and root growth of Trifolium vesiculosum (arrowleaf clover, an acid soil profile (60 cm depth with 67% Al saturation was recreated in a column (three layers of 20 cm each. Lime and fertilizer (P and K were incorporated into the top 20 cm. The treatments consisted of six boron rates where boric acid was mixed throughout the profile. Addition of boron to soil with low pH and high Al increased the root and shoot growth, independent of the rate applied. Boron inhibited Al toxicity, but no effect was observed in the root length when Al was not present in the soil. It was also observed that there was more root growth below the plow layer (0-20 cm, suggesting better root distribution in the soil profile which could be important for the plant growth, especially under drought conditions.Estudos têm mostrado que o boro (B afeta o crescimento das raízes em solo ácido reduzindo a toxidez do alumínio (Al. Para analisar a influência do boro no crescimento da parte aérea e raízes do Trifolium Vesiculosum (trevo vesiculoso um perfil de solo ácido (60 cm de profundidade com 67% de saturação de Al foi recriado em uma coluna (três camadas com 20 cm cada. Calcário e adubos (P e K foram incorporados na camada de 0-20 cm. Os tratamentos consistiram de seis doses de boro sendo o ácido bórico incorporado em todo o perfil. A adubação com boro em solo com baixo pH e elevado Al aumentou o crescimento da parte aérea e raízes, no entanto, independente da dose aplicada. Boro pode inibir a toxidez de Al, porém não observou-se efeito no comprimento de raízes sem a presença de Al no solo. Observou-se também um grande aumento no crescimento de raízes abaixo da camada arável (0-20 cm, fornecendo uma melhor distribuição de raízes no perfil do solo, o que pode ser importante para o crescimento da planta especialmente em condição de seca.

  12. State of the art regarding the safety analysis of boron dilution events in Germany

    International Nuclear Information System (INIS)

    Kliem, S.; Rohde, U.

    2006-01-01

    concentration of a reactor core should be lower than the minimum boron concentration at the core inlet, determined in the mixing experiments or obtained from reliable calculations. This approach contains a high amount of conservatism, because it is assumed that the boron concentration is uniform in the whole reactor core. The spatial and temporal distribution of the boron concentration in the reactor core, available from the detailed analyses, is not taken into account. A best-estimate approach has been developed at FZR and was applied to generic studies of BDT scenarios connected with start-up of the first MCP for German KONVOI type reactors. This approach starts with the definition of a scenario which covers all possible BDT scenarios with respect to reactivity consequences (maximum reactivity insertion). This is followed by a reactivity initiated accident (RIA) analysis using appropriate best-estimate tools (coupled 3D neutron kinetics/thermal hydraulic codes). Best-estimate boundary conditions for the boron concentration at the core inlet are applied. These are time-dependent boron concentration at the core inlet determined from experiments or CFD calculations. The final goal of the analysis is to show the integrity of the fuel rods. Usual acceptance limits with respect to maximum fuel temperature, maximum cladding temperature, radially averaged enthalpy deposited in the fuel and maximum cladding oxide layer thickness for RIA are applied. The use of this best estimate approach, which should be accompanied by an uncertainty analysis, can help to make the design of future reactor cores more flexible and economically not decreasing the safety level of the nuclear installations (Authors)

  13. Tracing water movement in Mumbai harbor bay using naturally occurring "2"2"4Ra and "2"2"3Ra as tracer

    International Nuclear Information System (INIS)

    Yadav, V.B.; Sartandel, S.J.; Jha, S.K.; Tripathi, R.M.

    2017-01-01

    Measurement of short lived radium isotopes "2"2"4Ra and "2"2"3Ra in seawater samples collected from Mumbai Harbor Bay was carried out using MnO_2 based in-situ pre-concentration technique coupled with coincidence counting. Longitudinal variation of "2"2"4Ra and "2"2"3Ra was found in the range 17.74 - 98.66 dpm/100L and 0.56 - 2.26 dpm/100L respectively. Higher value of radium isotopes was found near shore sampling points where reused seawater and surface water from land intrudes in creek. A decreasing pattern was observed in the creek as we move to offshore locations. Lower activity ratio in offshore locations indicates the flow of water towards open sea. (author)

  14. Sintering of beryllium oxide with 3-4 per cent elemental boron

    International Nuclear Information System (INIS)

    Pointud, R.; Rispal, Ch.; Le Garec, M.

    1958-01-01

    In order to manufacture a baffle absorbing neutrons of various energies, there was developed or mixture of a slower and an absorber. It is made by hot pressing impure beryllium containing boron carbide. The dense briquette has 100 x 100 x 50 mm and is machined on all her faces. She is of 2,85 density and about 3 to 4 per cent porosity, according to 5 per cent of boron. Difference of boron amount is lower than ten per cent between any two points of the briquette. (author) [fr

  15. Electrophoretic deposition of boron-10 in neutron detectors electrodes

    International Nuclear Information System (INIS)

    Oliveira Sampa, M.H. de; Vinhas, L.A.; Vieira, J.M.

    1990-01-01

    Process of boron-10 electrophoresis on large area of aluminum substrates was developed with the aim of using them in the construction of neutron detectors. After definition and optimization of the boron electrophoresis parameters, depositions of boron-10 on aluminum cylinders were performed and used as electrodes in gamma compensated and non-compensated ionization chambers and in proportional detectors. These prototypes were designed and builded at IPEN-CNEN-SP, and submited for characterization tests at IEA-R1 reactor, and they fulfil the technical specifications of the project. (author) [pt

  16. CVD boron nitride infiltration of fibrous structures: properties of low temprature deposits

    International Nuclear Information System (INIS)

    Gebhardt, J.J.

    1973-01-01

    The pyrolytic infiltration of boron nitride and silica fibrous structures with boron nitride was investigated using the thermal decomposition of B-trichloroborazole (TCB) to provide the matrix surrounding felted and 4-directional braided constructions. The deposition precursor was generated on a continuous basis by the reaction between boron trichloride and ammonium chloride in a fixed bed reactor under conditions of total conversion of the trichloride: 3BCl 3 + 3NH 4 Cl = B 3 N 3 H 3 Cl 3 + 9HCl. Deposition rates in boron nitride felt specimens varied between 8 and 28 μm/h, depending on the distance from the exterior surface at the minimum deposition temperature used (1100 0 C ). Infiltration of 4-directional silica braids was poorer because of clogging of the fiber bundle surfaces and access paths to voids in the weave. Deposits prepared at 1100 0 C and above were stable to moisture and consisted of glassy transparent materials which had no discernible x-ray diffraction pattern. Heat treatment of low temperature deposits in nitrogen at 1800 0 C caused significant growth of the crystallites and the emergence of x-ray patterns characteristic of hexagonal boron nitride. Heat treatment in vacuum caused changes in the infrared spectrum which could be correlated with mass analyses of the gases evolved. Loss of hydrogen with amines predominated to about 1500 0 C above which point the loss of nitrogen became significant. (14 figures) (U.S.)

  17. Removal of 226Ra, Fe3+ and Mn2+ from ground water using modified activated carbon

    International Nuclear Information System (INIS)

    Daifullah, A.A.M.

    2003-01-01

    A locally available biomass material, rice husk, was carbonized and activated in a steam/nitrogen flow by the use of a bench-scale fluidized bed reactor. The virgin carbon prepared from rice husk was further treated chemically using an alkali (e.g.10% NaOH and 10% KOH) in order to change the surface basicity of the carbon or oxidized with 30%H 2 O 2 and 10% HNO 3 in order to introduce different oxygen surface complexes. The modified carbons were characterized by FTIR and elemental analysis and investigated for removing unacceptably high concentrations of 326 Ra from ground water. The results showed that the best removal was obtained by the virgin carbon. The effect of process variables such as: contact time, Ph, carbon mass, sorbent surface modification and cation interference (e.g.iron and manganese) on the removal efficiency by the virgin carbon was studied. The data was fitted to Freundlich adsorption equation. Recommended procedures were adapted for complete removal of 226 Ra, Fe 3+ and Mn 2+ from ground water. Treated water quality remained good and no significant external radiation dose was caused to the residents

  18. PWR boron dilution transients. Thermal-hydraulic analyses of PKL-E experiments

    International Nuclear Information System (INIS)

    Pietro Alessandro Di Maio; Antonino Tomasello; Giuseppe Vella

    2005-01-01

    Full text of publication follows: In the field of PWR reactor safety, one of the topics that is currently of major interest worldwide is that of inadvertent boron dilution events. The safety issue involved in such scenarios is that inadvertent transport into the reactor core of un-borated water - or water having only a low boron concentration - can lead to local recriticality and possibly to power excursions. Studies on various accidental sequences that could initiate boron dilution events revealed that some SBLOCAs, occurring in the primary system, lead to reflux condenser conditions and subsequent re-establishment of natural circulation are of particular significance. In this work, the first field of analysis is related to the investigation of the thermal - hydraulic conditions that could lead to boron dilution events, such as the stop of natural circulation within primary system and the subsequent start of reflux condenser functioning mode. The investigation of the primary thermal - hydraulic conditions has been performed using the experimental results obtained in the PKL test integral facility in which some SBLOCA sequences have been carried out. Particular useful were the PKL III E experiments data whose results have been numerically reproduced using the code Relap5/MOD3.3/Beta code, contributing to understand the complex thermalhydraulic phenomena related to a PWR boron dilution event. The second field of analysis is related to the effects that possible displacements of un-borated water slugs towards the Reactor Pressure Vessel (RPV) could have on the core reactivity. A numerical approach using the Relap5 reactor kinetics model has been adopted to integrate the experimental thermal - hydraulic data obtained in the PKL III E tests. A careful analysis has been performed in order to establish which core conditions at incident start could produce the largest reactivity increase as a consequence of restarting of natural circulation during the primary system

  19. PWR boron dilution transients. Thermal-hydraulic analyses of PKL-E experiments

    Energy Technology Data Exchange (ETDEWEB)

    Pietro Alessandro Di Maio; Antonino Tomasello; Giuseppe Vella [Dipartimento di Ingegneria Nucleare, Viale delle Scienze, 90128 Palermo (Italy)

    2005-07-01

    Full text of publication follows: In the field of PWR reactor safety, one of the topics that is currently of major interest worldwide is that of inadvertent boron dilution events. The safety issue involved in such scenarios is that inadvertent transport into the reactor core of un-borated water - or water having only a low boron concentration - can lead to local recriticality and possibly to power excursions. Studies on various accidental sequences that could initiate boron dilution events revealed that some SBLOCAs, occurring in the primary system, lead to reflux condenser conditions and subsequent re-establishment of natural circulation are of particular significance. In this work, the first field of analysis is related to the investigation of the thermal - hydraulic conditions that could lead to boron dilution events, such as the stop of natural circulation within primary system and the subsequent start of reflux condenser functioning mode. The investigation of the primary thermal - hydraulic conditions has been performed using the experimental results obtained in the PKL test integral facility in which some SBLOCA sequences have been carried out. Particular useful were the PKL III E experiments data whose results have been numerically reproduced using the code Relap5/MOD3.3/Beta code, contributing to understand the complex thermalhydraulic phenomena related to a PWR boron dilution event. The second field of analysis is related to the effects that possible displacements of un-borated water slugs towards the Reactor Pressure Vessel (RPV) could have on the core reactivity. A numerical approach using the Relap5 reactor kinetics model has been adopted to integrate the experimental thermal - hydraulic data obtained in the PKL III E tests. A careful analysis has been performed in order to establish which core conditions at incident start could produce the largest reactivity increase as a consequence of restarting of natural circulation during the primary system

  20. New experimental space for irradiating samples by RA reactor fast neutron flux at temperatures up to 100 deg C

    International Nuclear Information System (INIS)

    Pavicevic, M.; Novakovic, M.; Zecevic, V.

    1961-01-01

    The objective of this paper is to present adaptation of the RA reactor which would enable samples irradiation by fast neutrons and describe new experimental possibilities. New experimental space was achieved using hollow fuel elements which have been reconstructed to enable placement of irradiation capsules inside the tube. This paper includes thermal analysis and describes problems related to operation, safety and radiation protection issues which arise from using reconstructed fuel elements

  1. Radiation protection at the RA Reactor in 1988, Part -2, Annex 2c, Environmental radioactivity control, meteorology measurements

    International Nuclear Information System (INIS)

    Grsic, Z.; Zaric, M.; Adamovic, M.; Stevanovic, M.

    1988-01-01

    During 1988, meteorology measurements were continued as a part of the environmental control of the Vinca Institute. This report covers the period from November 1984 - November 1985. Part of the meteorology measurements and data analysis is adapted to the needs of the Institute, i.e. RA reactor and some Laboratories. The objective of these activities is forming the data base for solving everyday and special problems related to control, protection and safety of Institute environment [sr

  2. Laser-time resolved fluorimetric determination of trace of boron in U3O8

    International Nuclear Information System (INIS)

    Xu Yongyuan; Wang Yulong; Wang Qin

    1988-01-01

    In this work, a laser-time resolved fluorimetric determinatin of trace of boron in U 3 O 8 had been developed. The boron complex with dibenzoyl methane (DBM) in a suitable medium is excited by a small nitrogen laser and emits the delay fluorescence with lifetime of 2 ms which is much longer than that of the fluorescence of uranium. Since the fluorescence of uranium doesn't interfere with determination of boron in the time resolved fluorimetric method boron need not be separated from uranium in advance. Thus the determination is very rapid and simple. The limit of determination is 0.02 ngB/ml. When 10 mgU is taken, 0.01 ppm of boron in uranium can be determined. Several samples of U 3 O 8 with boron content from 0.04 to 0.5 ppm have been determined by using this method. The results of determination have been accordant with other methods

  3. New Small LWR Core Designs using Particle Burnable Poisons for Low Boron Concentration

    International Nuclear Information System (INIS)

    Yoo, Ho Seong; Hwang, Dae Hee; Hong, Ser Gi

    2015-01-01

    The soluble boron has two major important roles in commercial PWR operations : 1) the control of the long-term reactivity to maintain criticality under normal operation, and 2) the shutdown of the reactor under accidents. However, the removal of the soluble boron gives several advantages in SMRs (Small Modular Reactor). These advantages resulted from the elimination of soluble boron include the significant simplification of nuclear power plant through the removal of pipes, pumps, and purification systems. Also, the use of soluble boron mitigates corrosion problems on the primary coolant loop. Furthermore, the soluble boron-free operation can remove an inadvertent boron dilution accident (BDA) which can lead to a significant insertion of positive reactivity. From the viewpoint of core physics, the removal of soluble boron or reduction of soluble boron concentration makes the moderator temperature coefficient (MTC) more negative. From the core design studies using new fuel assemblies, it is shown that the cores have very low critical soluble boron concentrations less than 500ppm, low peaking factors within the design targets, strong negative MTCs over cycles, and large enough shutdown margins both at BOC and EOC. However, the present cores have relatively low average discharge burnups of ∼ 30MWD/kg leading to low fuel economy because the cores use lots of non-fuel burnable poison rods to achieve very low critical boron concentrations. So, in the future, we will perform the trade-off study between the fuel discharge burnup and the boron concentrations by changing fuel assembly design and the core loading pattern

  4. New Small LWR Core Designs using Particle Burnable Poisons for Low Boron Concentration

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Ho Seong; Hwang, Dae Hee; Hong, Ser Gi [Kyung Hee University, Yongin (Korea, Republic of)

    2015-05-15

    The soluble boron has two major important roles in commercial PWR operations : 1) the control of the long-term reactivity to maintain criticality under normal operation, and 2) the shutdown of the reactor under accidents. However, the removal of the soluble boron gives several advantages in SMRs (Small Modular Reactor). These advantages resulted from the elimination of soluble boron include the significant simplification of nuclear power plant through the removal of pipes, pumps, and purification systems. Also, the use of soluble boron mitigates corrosion problems on the primary coolant loop. Furthermore, the soluble boron-free operation can remove an inadvertent boron dilution accident (BDA) which can lead to a significant insertion of positive reactivity. From the viewpoint of core physics, the removal of soluble boron or reduction of soluble boron concentration makes the moderator temperature coefficient (MTC) more negative. From the core design studies using new fuel assemblies, it is shown that the cores have very low critical soluble boron concentrations less than 500ppm, low peaking factors within the design targets, strong negative MTCs over cycles, and large enough shutdown margins both at BOC and EOC. However, the present cores have relatively low average discharge burnups of ∼ 30MWD/kg leading to low fuel economy because the cores use lots of non-fuel burnable poison rods to achieve very low critical boron concentrations. So, in the future, we will perform the trade-off study between the fuel discharge burnup and the boron concentrations by changing fuel assembly design and the core loading pattern.

  5. Structural modifications induced by ion irradiation and temperature in boron carbide B4C

    Science.gov (United States)

    Victor, G.; Pipon, Y.; Bérerd, N.; Toulhoat, N.; Moncoffre, N.; Djourelov, N.; Miro, S.; Baillet, J.; Pradeilles, N.; Rapaud, O.; Maître, A.; Gosset, D.

    2015-12-01

    Already used as neutron absorber in the current French nuclear reactors, boron carbide (B4C) is also considered in the future Sodium Fast Reactors of the next generation (Gen IV). Due to severe irradiation conditions occurring in these reactors, it is of primary importance that this material presents a high structural resistance under irradiation, both in the ballistic and electronic damage regimes. Previous works have shown an important structural resistance of boron carbide even at high neutron fluences. Nevertheless, the structural modification mechanisms due to irradiation are not well understood. Therefore the aim of this paper is to study structural modifications induced in B4C samples in different damage regimes. The boron carbide pellets were shaped and sintered by using spark plasma sintering method. They were then irradiated in several conditions at room temperature or 800 °C, either by favoring the creation of ballistic damage (between 1 and 3 dpa), or by favoring the electronic excitations using 100 MeV swift iodine ions (Se ≈ 15 keV/nm). Ex situ micro-Raman spectroscopy and Doppler broadening of annihilation radiation technique with variable energy slow positrons were coupled to follow the evolution of the B4C structure under irradiation.

  6. Determination of 226Ra and 228Ra in gypsum

    International Nuclear Information System (INIS)

    Godoy, J.M.

    1989-01-01

    The content of 226 Ra and 228 Ra in different samples of phosphogypsum and three samples of gypsite were determined by gamma spectroscopy. For 226 Ra the 295, 352 and 609 KeV lines and for 228 Ra the 911 and 969 KeV lines were used. The specific activities values ranged from 0.36 to 22.8 pCi/g for 226 Ra and 0.90 to 10.3 pCi/g for 228 Ra. The contribution of a sypsum roof-covering to the 222 Rn concentration in a room was estimated, based on the highest value reported. (author) [pt

  7. Action plan for the task: Physical measurements at the RA reactor related to VISA-2 project, '0' program, Reactor start-up and measurement of basic parameters of the new core; Plan rada po zadatku: Fizicka merenja na reaktoru RA u vezi projekta VISA-2, '0' program, Pustanje u rad reaktora RA i merenje osnovnih parametara novog jezgra

    Energy Technology Data Exchange (ETDEWEB)

    Markovic, H; Raisic, N [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1962-07-01

    This report consists of two parts. Part one describes the RA reactor start-up, measurements of thermal neutron flux distribution, measurements of epithermal flux, fast neutron flux distribution, absolute values of both thermal and fast neutron fluxes, calibration of regulating rods, and measurements of neutron flux inside the fuel elements. All the mentioned measurements were done at low power level. Part two includes description of the reactor power increase up to nominal value of 6.5 MW, and measurements of thermal neutron flux distribution under xenon poisoning conditions, measurements of epithermal neutrons, absolute values of both thermal and fast neutron fluxes, and measurements of thermal and epithermal neutron fluxes at the exit of the horizontal experimental channel HK-d.

  8. Operation, maintenance and utilization of the RA reactor - Report on operation in 1979; Pogon, odrzavanje i eksploatacija reaktora RA, Izvestaj o radu u 1979. godini

    Energy Technology Data Exchange (ETDEWEB)

    Milosevic, M

    1979-12-15

    During 1979 the RA reactor was in operation only three months, i.e. only 24% of the planned activity was achieved. The reactor operation was interrupted in March due to problems that could not be solved by the existing equipment. Alkalinity of the heavy water resulting from the existing ammonia ions could not be removed by the existing distillation system. In addition deposition of aluminium oxyhydrate on the fuel elements was increased. This was noticed during routine control when the reactor was shutdown for refueling. The decision of the Director general of the Institute and sanitary Inspector followed, prohibiting further reactor operation. A separate chapter of this report is devoted to the analysis of the difficulties and possible solution of the problem in cooperation with the experts from different laboratories of the Institute. Aged and damaged instruments at the reactor were not exchange due to lack of budget. During the operation there were no accidents. [Serbo-Croat] U toku 1979. godine plan rada ostvaren je sa 24%, odnosno reaktor je radio samo prva tri meseca. U martu je doslo do prekida rada reaktora zbog pojave koja se nije mogla otkloniti postojecom opremom. Alkalnost teske vode, posledica prisustva amonijum jona, ne moze se odstraniti sistemom destilacije. Pored toga usled dotrajalosti opreme povecano je talozenje aluminijum oksihidroksida na gorivnim elementima. Ova pojava uocena je tokom rutinske kontrole prilikom izmene goriva a usledila je obustava rada resenjem Direktora i sanitarnog inspektora. Posebno poglavlje ovog izvestaja posveceno je analizi teskoca u radu i reaktora i resavanju nastalih problema sa gorivom u saradnji sa saradnicima drugih laboratorija Instituta. Dotrajali uredjaji i oprema nisu zamenjeni usled nedostatka sredstava. U toku rada nije bilo akcidenata.

  9. Boron autoradiography method applied to the study of steels

    International Nuclear Information System (INIS)

    Gugelmeier, R.; Barcelo, G.N.; Boado, J.H.; Fernandez, C.

    1986-01-01

    The boron state, contained in the steel microestructure, is determined. The autoradiography by neutrons is used, permiting to obtain boron distribution images by means of additional information which is difficult to acquire by other methods. The application of the method is described, based on the neutronic irradiation of a polished steel sample, over which a celulose nitrate sheet or other appropriate material is fixed to constitute the detector. The particles generated by the neutron-boron interaction affect the detector sheet, which is subsequently revealed with a chemical treatment and can be observed at the optical microscope. In the case of materials used for the construction of nuclear reactors, special attention must be given to the presence of boron, since owing to the exceptionaly high capacity of neutron absorption, lowest quantities of boron acquire importance. The adaption of the method to metallurgical problems allows the obtainment of a correlation between the boron distribution images and the material's microstructure. (M.E.L.) [es

  10. ICRF boronization. A new technique towards high efficiency wall coating for superconducting tokamak reactors

    International Nuclear Information System (INIS)

    Li Jiangang; Zhao Yan Ping; Gu Xue Mao

    1999-01-01

    A new technique for wall conditioning that will be especially useful for future larger superconducting tokamaks, such as ITER, has been successfully developed and encouraging results have been obtained. Solid carborane powder, which is non-toxic and non-explosive, was used. Pulsed RF plasma was produced by a non-Faraday shielding RF antenna with RF power of 10 kW. The ion temperature was about 2 keV with a toroidal magnetic field of 1.8 T and a pressure of 3x10 -1 Pa. Energetic ions broke up the carborane molecules, and the resulting boron ions struck and were deposited on the first wall. In comparison with glow discharge cleaning boronization, the B/C coating film shows higher adhesion, more uniformity and longer lifetime during plasma discharges. The plasma performance was improved after ICRF boronization. (author). Letter-to-the-editor

  11. 226Ra, 228Ra and 228Ra/226Ra in surface marine sediment of Malaysia

    International Nuclear Information System (INIS)

    Mei-Wo Yii; Zal Uyun Wan-Mahmood

    2013-01-01

    Surface sediment samples were collected at the West (east coast and west coast of Peninsular Malaysia) and East (Sabah and Sarawak) Malaysia in several expeditions within August 2003 until June 2008 for determining the level of natural radium isotopes. Activity concentrations of 226 Ra and 228 Ra in surface marine sediment at 176 sampling stations were measured. The activity concentrations of both radionuclides in Malaysia (East and West Malaysia) display varied with the range from 9 to 158 Bq/kg dry wt. and 13 to 104 Bq/kg dry wt., respectively. Meanwhile, the ratio distributions of 228 Ra/ 226 Ra were ranged from 0.62 to 3.75. This indicated that the ratios were slightly high at west coast of Peninsular Malaysia compared to other regions (east coast of Peninsular Malaysia, Sabah and Sarawak). The variation of activity concentrations of 226 Ra and 228 Ra and its ratios were also supported by the statistical analyses of one-way ANOVA and t test at 95 % confidence level, whereby there were proved that the measured values were different between the regions. These different were strictly related to their half-life, potential input sources (included their parents, 238 U and 232 Th), parent's characteristic, the geological setting/formation of the study area, environment origin and behavior. (author)

  12. Visualization of boron in molybdenum by α-rays track etching method and tritium autoradiography

    International Nuclear Information System (INIS)

    Saito, Hideo; Morita, Fumio

    2003-01-01

    Molybdenum alloys addicted with < 0.02 ppm B to 160 ppm B were analyzed by α-rays track etching (ATE) method irradiated by thermal neutron for 12 hours using atomic reactor of Rikkyo University and Japan atomic reactor of JRR-4. It was found that boron was segregated along grain boundaries and in the matrix. We analyzed boron distribution in the vicinity of the triple junctions at grain boundaries and in the matrix by the statistical frequency of α-rays tracks. Also we studied tritium autoradiography by cathodic charging method. Visualization of boron distribution was confirmed along the grain boundary which seemed to be effective trapping sites of hydrogen. (author)

  13. Boron steel. I Part. Preparation

    International Nuclear Information System (INIS)

    Jaraiz Franco, E.; Esteban Hernandez, J. A.

    1960-01-01

    With the advent of the first nuclear reactors arise the need for control rods and shielding duties for some types of radiations. One of the materials used for this purpose has been the high boron steel. This paper describes the melting and casting procedures employed for the production, at laboratory scale, of steels with Boron content ranging from 1 to 4 per cent, as well as the metallographic and X-Ray techniques used for the identification of the present phases. The electrolytic technique employed for the isolation of the Fe 2 B phase and its subsequent X-Ray identification has proved to be satisfactory. (Author) 11 refs

  14. Improved ductility of Ni3Si by microalloying with boron or carbon

    International Nuclear Information System (INIS)

    Taub, A.I.; Briant, C.L.

    1989-01-01

    The effects of boron and carbon additions on the tendency for intergranular fracture in trinickel silicide intermetallics are reported. Melt spinning of Ni 77 Si 23 alloyed with 0.1 at. pct boron results in full bend ductility and complete transgranular fracture compared with brittle intergranular fracture for the unmodified compound. Alloying with 0.1 at. pct carbon also produced full bend ductility but a mixed mode failure (30 pct transgranular). For both carbon and boron additions, reducing the Ni concentration of the base compound results in a greater percentage of intergranular fracture. For Ni 77 Si 23 , the solubility limit is between 0.1 and 0.2 t. pct boron. For compounds with silicon concentrations of 23.5 and 24.0 at. pct, the solubility limit is less than 0.1 at. pct boron. Boron additions above the solubility limit result in Ni 3 B precipitates which degrade the bend ductility and increase the percentage of intergranular fracture. Alloying with carbon above the solubility limit ( 77 Si 23 , increasing the carbon concentration from 0.1 to 1.0 at. pct resulted in no change in the ductility. Auger examination of the grain boundary composition showed strong segregation of both boron and carbon. Enrichment in silicon concentration was also observed

  15. Radiation protection at the RA Reactor in 1985, Part -3, Removal and treatment of radioactive effluents for the needs of RA reactor

    International Nuclear Information System (INIS)

    Plecas, I.; Vukovic, Z.; Kostadinovic, A.

    1985-01-01

    Contaminated water originates from: hot cells, heavy water distillation device, storage pools for cooling and cutting of fuel elements, water biological shield of the reactor. During 1985 5 m of contaminated water was released from hot cells in the VR-pool containing highly radioactive waste water with 60 Co and trace amount of fission products [sr

  16. Feasibility study of SMART core with soluble boron

    International Nuclear Information System (INIS)

    Kim, Kang Seog; Lee, Chung Chan; Zee, Sung Quun

    2000-11-01

    The excess reactivity of SMART core without soluble boron is effectively controlled by 49 CEDM. We suggest another method to control the core excess reactivity using both the checkerboard type of 25 CEDM and soluble boron and perform a feasibility calculation. The soluble boron operation is categorized into the on-line and the off-line mechanisms. The former is to successively control the boron concentration according to the excess reactivity during operation and the latter is to add and change some soluble boron during refueling and repairing. Since the on-line soluble boron control system of SMART is conceptually identical to that of the commercial pressurized water reactor, we did not perform the analysis. Since the soluble boron in the complete off-line system increases the moderator temperature coefficient, the reactivity defect between hot and cold moderator temperature is decreased. However, the decrease of the reactivity is not big to satisfy the core reactivity limits. When using 25 CEDM, the possible mechanism is to control the excess reactivity by both control rod and on-line boron control mechanism between cold and hot zero power and by only control rod at hot full power. We selected the loading pattern satisfying the requirement in the view of nuclear design

  17. Activity report on the utilization of research reactors (JRR-3 and JRR-4). Japanese fiscal year, 2009

    International Nuclear Information System (INIS)

    2014-02-01

    JRR-3 is used for the purposes below; Experimental studies such as neutron scattering, prompt gamma-ray analyses, neutron radiography, Irradiation for activation analyses, radioisotope (RI) productions, fission tracks, Irradiation test of reactor materials, etc. JRR-4 is used for the purposes below; Medical irradiation (Boron Neutron Capture Therapy : BNCT), Prompt gamma-ray analyses, Sensitivity measurement of radiation detectors, Experiment in the nuclear reactor training, Practice of Reactor operation, Irradiation for activation analyses, RI productions, fission tracks, etc. In the fiscal year 2009, The research reactor JRR-3 was operated 7 cycles (cycle operation : 26days/cycle) for utilization sharing of the facility. And JRR-4 was operated 6 cycles (daily operation : 24 days). The volume contains 138 activity reports, which are categorized into the fields of neutron scattering (11 subcategories), neutron radiography, prompt gamma-ray analyses, neutron activation analyses, RI productions, and others submitted by the users in JAEA and from other organizations. (author)

  18. Activity report on the utilization of research reactors (JRR-3 and JRR-4). Japanese fiscal year, 2005

    International Nuclear Information System (INIS)

    2007-03-01

    In the fiscal year 2005, The research reactor JRR-3 was operated 7 cycles (cycle operation : 26days/cycle) for utilization sharing of the facility. And JRR-4 was operated 37 cycles (daily operation : 137 days). JRR-3 is used for the purposes below; Experimental studies such as neutron scattering, prompt gamma-ray analyses, neutron radiography. Irradiation for activation analyses, radioisotope (RI) productions, fission tracks. Irradiation test of reactor materials etc. JRR-4 is used for the purposes below; Medical irradiation (Boron Neutron Capture Therapy : BNCT). Prompt gamma-ray analyses. Sensitivity measurement of radiation detectors. Experiment in the nuclear reactor training. Practice of Reactor operation. Irradiation for activation analyses, RI productions, fission tracks etc. The volume contains 100 activity reports, which are categorized into the fields of neutron scattering (9 subcategories), neutron radiography, neutron activation analyses, RI productions, prompt gamma-ray analyses, and others submitted by the users in JAEA and from other organizations. (author)

  19. Activity report on the utilization of research reactors (JRR-3 and JRR-4). Japanese fiscal year, 2006

    International Nuclear Information System (INIS)

    2009-01-01

    In the fiscal year 2006, the research reactor JRR-3 was operated 7 cycles (cycle operation: 26 days/cycle) for utilization sharing of the facility. And JRR-4 was operated 37 cycles (daily operation: 151 days). JRR-3 is used for the purposes below; Experimental studies such as neutron scattering, prompt gamma-ray analyses, neutron radiography, Irradiation for activation analyses, radioisotope (RI) productions, fission tracks, Irradiation test of reactor materials, etc. JRR-4 is used for the purposes below; Medical irradiation (Boron Neutron Capture Therapy : BNCT), Prompt gamma-ray analyses, Sensitivity measurement of radiation detectors, Experiment in the nuclear reactor training, Practice of Reactor operation, Irradiation for activation analyses, RI productions, fission tracks, etc. The volume contains 294 activity reports, which are categorized into the fields of neutron scattering (11 subcategories), neutron radiography, neutron activation analyses, RI productions, prompt gamma-ray analyses, and others submitted by the users in JAEA and from other organizations. (author)

  20. Activity report on the utilization of research reactors (JRR-3 and JRR-4). Japanese fiscal year, 2009

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-02-15

    JRR-3 is used for the purposes below; Experimental studies such as neutron scattering, prompt gamma-ray analyses, neutron radiography, Irradiation for activation analyses, radioisotope (RI) productions, fission tracks, Irradiation test of reactor materials, etc. JRR-4 is used for the purposes below; Medical irradiation (Boron Neutron Capture Therapy : BNCT), Prompt gamma-ray analyses, Sensitivity measurement of radiation detectors, Experiment in the nuclear reactor training, Practice of Reactor operation, Irradiation for activation analyses, RI productions, fission tracks, etc. In the fiscal year 2009, The research reactor JRR-3 was operated 7 cycles (cycle operation : 26days/cycle) for utilization sharing of the facility. And JRR-4 was operated 6 cycles (daily operation : 24 days). The volume contains 138 activity reports, which are categorized into the fields of neutron scattering (11 subcategories), neutron radiography, prompt gamma-ray analyses, neutron activation analyses, RI productions, and others submitted by the users in JAEA and from other organizations. (author)

  1. Biological Tests for Boron Neutron Capture Therapy Research at the TRIGA Mark II Reactor in Pavia

    Energy Technology Data Exchange (ETDEWEB)

    Protti, N.; Ballarini, F.; Bortolussi, S.; De Bari, A.; Stella, S.; Altieri, S. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); Nuclear Physics National Institute (INFN), Pavia (Italy); Bruschi, P. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); Bakeine, J.G.; Cansolino, L.; Clerici, A.M. [Laboratory of Experimental Surgery, Department of Surgery, University of Pavia, Pavia (Italy)

    2011-07-01

    The thermal column of the TRIGA Mark II reactor of the Pavia University is used as an irradiation facility to perform biological tests and irradiations of living systems for Boron Neutron Capture Therapy (BNCT) research. The suitability of the facility has been ensured by studying the neutron flux and the photon background in the irradiation chamber inside the thermal column. This characterization has been realized both by flux and dose measurements as well as by Monte Carlo simulations. The routine irradiations concern in vitro cells cultures and different tumor animal models to test the efficacy of the BNCT treatment. Some results about these experiments will be described. (author)

  2. Study of the processes of changing the crystal structure of boron carbide after the destruction of a nuclear reactor as a result of earthquake

    International Nuclear Information System (INIS)

    Mammadov, Kh.; Mirzayev, M.; Garibov, R.; Allahverdiyev, G.

    2017-01-01

    The territories of the Trans Caucasian Republics are characterized by high seismic activity. Therefore, the occurrence of cases of anthropogenic catastrophe including in the territories of nuclear reactors is not ruled out in case of natural disasters. Studies to create detectors based on B 4 C for recording ''cold'', ''hot'' and ''fast'' neutrons in order to increase the safety of nuclear reactors have been carried out in recent years. The B 4 C crystal structure is highly stable at relatively large intervals of temperature and pressure. The study of the thermo physical properties of samples of boron carbide irradiated with ionizing beams is interesting from the point of view to study of the stability of the structure and the stability of this compound. The thermal properties of B 4 C irradiated with ionizing γ radiation from a 60''Co source were investigated using the differential scanning calorimetric (DSC) methods. Upon irradiation with ionizing γ rays, a discrete change in the energy of the atoms occurs at the sites of the crystal lattice, the formation of active centers (radicals, ions, electrons), defects in the crystal lattice, the evaporation of crystalline hydrates, which are present in small amounts in bulk and crystalline compounds. The melting point of B 2 O 3 is 723 K, for boron 2348 K, for B 4 C 2623 K. The melting enthalpy for B 2 O 3 is 24.6 kJ/mol. With increasing temperature, the heat capacity and entropy of the non irradiated and irradiated B 4 C samples are increased. The nature of the change in the enthalpy and the Gibbs potential with increasing temperature depends on the presence of oxygen upon irradiation and during thermogravimetric analysis in the temperature range 298-1300 K. Changes in the values of thermodynamic functions occur due to the formation (under the influence of ionizing radiation) of excited atoms, active centers, defects in the crystal structure of

  3. Activity report on the utilization of research reactors (JRR-3 and JRR-4). Japanese fiscal year, 2007

    International Nuclear Information System (INIS)

    2012-03-01

    In the fiscal year 2007, the research reactor JRR-3 was operated for 7 cycles (cycle operation : 26days/cycle) and the JRR-4 was operated for 92 days. JRR-3 is used for the purposes below; Experimental studies such as neutron scattering, prompt gamma-ray analyses, neutron radiography, Irradiation for activation analyses, radioisotope (RI) productions, fission tracks, Irradiation test of reactor materials, etc. JRR-4 is used for the purposes below; Medical irradiation (Boron Neutron Capture Therapy : BNCT), Prompt gamma-ray analyses, Sensitivity measurement of radiation detectors, Experiment and practice in the nuclear reactor training, Irradiation for activation analyses, RI productions, fission tracks, etc. The volume contains 262 activity reports, which are categorized into the fields of neutron scattering (10 subcategories), neutron radiography, neutron activation analyses, prompt gamma-ray analyses, and others submitted by the users in JAEA and other Organizations. (author)

  4. RAPIDARC (RA) in the uterine cervical cancer; dosimetric gain vs 3D-Crt; RAPIDARC (RA) en el cancer de cervix uterino; ganancia dosimetrica vs 3D-CRT

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, J.; Garcia, B.; Quispe, K.; Gonzales, A.; Marquina, J., E-mail: jose.ramirez@aliada.com.pe [Clinica Aliada, Oncologia Integral, Av. Jose Galvez Barrenechea 1044, San Isidro, Lima (Peru)

    2014-08-15

    This work aims to quantitatively assess RAPIDARC (RA) treatments versus three dimensional-Conformal Radiation Therapy with field to field technique (3D-Crt-Fin F). 11 patients with cervical cancer treated at our institution radically or adjuvant clinical stages I-III B were evaluated. The prescribed dose was 50 Gy (2 Gy / Fr). The RA plans consisted of two isocentric complete arcs and conformational plans of 4 isocentric fields (previous, subsequent, right side and left side) with 3D-Crt-Fin F technique; both cases carried out ??in the Eclipse version 10 planner with calculation algorithm analytical anisotropic algorithm (AAA) and volumetric optimization software (for VMAT plans). Homogeneity indices (Hi), conformity indices (CI) Sigma indices (S-Index), monitor units (MU) and the time required for each treatment were compared. The mean age was 52 years (32-65) of the 11 patients 9 were clinical stages I-II B. The Hi varied from 0.052 for RA to 0.163 for 3D-Crt-Fin F (p = 0.009), and the CI between 1.005 and 1.35 (p = 0.26), the S-index from 1.2 to 3.7 (p = 0.001) and the H-index of 1.08 to 1.15 (p = 0.24). All dose limits in risk organs were met with a significant difference in the RA plans versus 3D-Crt-Fin F. In patients with cervical cancer the treatment plans quality with the indices aforementioned seems to be better with the RA technique, being observed a significant reduction of radiation to surrounding organs. (author)

  5. Structural modifications induced by ion irradiation and temperature in boron carbide B{sub 4}C

    Energy Technology Data Exchange (ETDEWEB)

    Victor, G., E-mail: g.victor@ipnl.in2p3.fr [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); Pipon, Y.; Bérerd, N. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); Institut Universitaire de Technologie (IUT) Lyon-1, Université Claude Bernard Lyon 1, 69622 Villeurbanne Cedex (France); Toulhoat, N. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); CEA-DEN, Saclay, 91191 Gif-sur-Yvette (France); Moncoffre, N. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); Djourelov, N. [Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, 72 Tzarigradsko chaussee blvd, BG-1784 Sofia (Bulgaria); ELI-NP, IFIN-HH, 30 Reactorului Str, MG-6 Bucharest-Magurele (Romania); Miro, S. [CEA-DEN, Service de Recherches de Métallurgie Physique, Laboratoire JANNUS, F-91191 Gif-sur-Yvette (France); Baillet, J. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); Pradeilles, N.; Rapaud, O.; Maître, A. [SPCTS, UMR CNRS 7315, Centre Européen de la céramique, University of Limoges (France); Gosset, D. [CEA, Saclay, DMN-SRMA-LA2M, 91191 Gif-sur-Yvette (France)

    2015-12-15

    Already used as neutron absorber in the current French nuclear reactors, boron carbide (B{sub 4}C) is also considered in the future Sodium Fast Reactors of the next generation (Gen IV). Due to severe irradiation conditions occurring in these reactors, it is of primary importance that this material presents a high structural resistance under irradiation, both in the ballistic and electronic damage regimes. Previous works have shown an important structural resistance of boron carbide even at high neutron fluences. Nevertheless, the structural modification mechanisms due to irradiation are not well understood. Therefore the aim of this paper is to study structural modifications induced in B{sub 4}C samples in different damage regimes. The boron carbide pellets were shaped and sintered by using spark plasma sintering method. They were then irradiated in several conditions at room temperature or 800 °C, either by favoring the creation of ballistic damage (between 1 and 3 dpa), or by favoring the electronic excitations using 100 MeV swift iodine ions (S{sub e} ≈ 15 keV/nm). Ex situ micro-Raman spectroscopy and Doppler broadening of annihilation radiation technique with variable energy slow positrons were coupled to follow the evolution of the B{sub 4}C structure under irradiation.

  6. ICP-MS determination of boron: method optimization during preparation of graphite reference material for boron

    International Nuclear Information System (INIS)

    Granthali, S.K.; Shailaja, P.P.; Mainsha, V.; Venkatesh, K.; Kallola, K.S.; Sanjukta, A.K.

    2017-01-01

    Graphite finds widespread use in nuclear reactors as moderator, reflector, and fuel fabricating components because of its thermal stability and integrity. The manufacturing process consists of various mixing, moulding and baking operations followed by heat-treatment between 2500 °C and 3000 °C. The high temperature treatment is required to drive the amorphous carbon-to-graphite phase transformation. Since synthetic graphite is processed at high temperature, impurity concentrations in the precursor carbon get significantly reduced due to volatilization. However boron may might partly gets converted into boron carbide at high temperatures in the carbon environment of graphite and remains stable (B_4C: boiling point 3500 °C) in the matrix. Literature survey reveals the use of various methods for determination of boron. Previously we have developed a method for determination of boron in graphite electrodes using inductively coupled plasma mass spectrometry (ICP-MS). The method involves removal of graphite matrix by ignition of the sample at 800°C in presence of saturated barium hydroxide solution to prevent the loss of boron. Here we are reporting a modification in the method by using calcium carbonate in place of barium hydroxide and using beryllium (Be) as an internal standard, which resulted in a better precession. The method was validated by spike recovery experiments as well as using another technique viz. Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The modified method was applied in evaluation of boron concentration in the graphite reference material prepared

  7. Effect of boron additions and processing on microstructure and mechanical properties of a titanium alloy Ti–6.5Al–3.3Mo–0.3Si

    Energy Technology Data Exchange (ETDEWEB)

    Imayev, V.M., E-mail: vimayev@mail.ru; Gaisin, R.A.; Imayev, R.M.

    2015-08-12

    The effects of boron additions in an amount of 0.1–2 wt%, thermomechanical processing and heat treatment on microstructure and mechanical properties of a two-phase titanium alloy Ti–6.5Al–3.3Mo–0.3Si alloy have been investigated. Depending on the boron amount, the materials under study were divided into two groups: (1) boron modified alloys containing ~0.1 wt% of boron and (2) discontinuously reinforced metal matrix Ti–TiB based composites containing 1.5–2 wt% of boron. Boron additions led to formation of TiB whiskers, which were predominantly located along boundaries of prior β-grains and α-colonies resulting in refined as-cast microstructure. Multiple 3D forging at T=650–700 °C applied for the boron modified alloys resulted in formation of ultrafine-grained microstructure and intensive breaking of TiB whiskers. Tensile properties of the Ti–6.5Al–3.3Mo–0.3Si–0.2 wt% B alloy after multiple 3D forging followed by β-heat treatment were found to be appreciably higher than those of the alloy free of boron after the same processing route that was ascribed to better controlling the β-grain size during β heat treatment. The composite materials were subjected to multiple isothermal 2D forging at T=950 °C that provided effective alignment of TiB whiskers while retaining their high aspect ratio. The hot forged composites demonstrated appreciably higher strength, creep resistance in comparison with those of the base alloy without drastic reduction in ductility. The effect of TiB whiskers orientation and morphology on the tensile properties of the composite materials is discussed.

  8. Safety report for the Independent CO{sub 2} loop for cooling the samples irradiated in the RA reactor vertical experimental channels, Vol. VI; Album VI: Izvestaj o sigurnosti za nezavisno kolo CO{sub 2} za hladjenje uzoraka ozracivanih u VEK reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1964-07-01

    First part of the safety report for the Independent CO{sub 2} loop for cooling the samples irradiated in the RA reactor vertical experimental channels contains descriptions of the independent CO{sub 2} loop, system for regulation, measurement and control od the loop parameters, description of the dosimetry system, and the plan for testing the experimental device before start-up. Second part of this analysis describes the influence of of the experimental device on the reactor operation under steady state conditions as follows: influence of the head of the independent coolant loop on the reactivity of the reactor core and influence on the reactor temperature coefficient. Third part of the report includes the analysis of possible accidents during operation of the independent CO{sub 2} coolant loop in the reactor. Izvestaj o sigurnosti za nezavisno kolo CO{sub 2} za hladjenje uzoraka ozracivanih u VEK reaktora RA sadrzi u prvom delu: opis nezavisnog kola CO{sub 2}, sistema za regulaciju, merenje i kontrolu parametara nezavisnog kola, sistema dozimetrijske kontrole i plan ispitivanja eksperimentalnih uredjaja pre pustanja u rad. Drugi deo ove analize obuhvata uticaj eksperimentalnog uredjaja na reaktor u normalnom rezimu rada i to: uticaj glave petlje nezavisnog kola CO{sub 2} za hladjenje uzoraka na reaktivnost reaktora i uticaj uredjaja na temperaturni koeficijent reaktora. Treci deo sadrzi analizu mogucih akcidenata u toku rada nezavisnog kola CO{sub 2} u reaktoru.

  9. Current activities on improving storage conditions of the research reactor RA spent fuel - Part II

    International Nuclear Information System (INIS)

    Matausek, M.V.; Kopecni, M.; Vukadin, Z.; Plecas, I.; Pavlovic, R.; Sotic, O.; Marinkovic, N.

    1998-01-01

    To minimize further corrosion and preserve integrity of aluminum barrels and the stainless steel channel-type containers that were found to contain leaking spent fuel, actions to improve conditions in the existing spent fuel storage pool at the RA research reactor were initiated. Technology was elaborated and equipment was produced and applied for removal of sludge and other debris from the bottom of the pool, filtration of the pool water, sludge conditioning in cement matrix and disposal at the low and medium waste repository at VINCA site. More sophisticated operations are to be performed together with foreign experts. Safety measures and precautions were determined. Subcriticality was proved under normal and/or possible abnormal conditions. (author)

  10. Status report about the works for the start up of the RA-0 `zero power` nuclear reactor at the Cordoba National University; Estado actual de avance de las tareas para la nueva puesta en marcha del reactor nuclear RA-0 en la Universidad Nacional de Cordoba

    Energy Technology Data Exchange (ETDEWEB)

    Martin, H R; Carballido, C; Oliveras, T

    1992-12-31

    After two years of works at the Cordoba National University for the new start-up of the RA-0 `zero power` nuclear reactor, the results obtained are herein presented. Starting with practically null infrastructure at the beginning, specially in human resources and instrumentation of the reactor, the objectives can be considered satisfactory. The training in work of the future operational staff, the design and the construction of the instrumentation and the fitting of the installations are the principal items described in this paper. An special attention is devoted to the insertion of this type of installation in the university organization, usually not prepared for the quality and control activities, which is necessarily considered in these type of works. (Author). [Espanol] Luego de aproximadamente dos anos de trabajo para la nueva puesta en marcha del REACTOR NUCLEAR RA-0, se han alcanzado los resultados presentados en este trabajo. Partiendo de una infraestructura practicamente inexistente en cuanto a recursos humanos y estado de las instalaciones, los avances logrados son significativos. Comenzando por la capacitacion y el entrenamiento del futuro personal de operacion y pasando por la adecuacion de los equipos y componentes, hasta la confeccion de la documentacion mandatoria, se muestran los aspectos mas destacables de los trabajos realizados. Una atencion especial se dedica a la insercion de una instalacion de este tipo en el ambito universitario, el cual por sus particulares caracteristicas, ha debido ser tenido en cuenta permanentemente para la futura operacion de las instalaciones. (Autor).

  11. The Boron Neutron Capture Therapy (BNCT) Project at the TRIGA Reactor in Mainz, Germany

    Energy Technology Data Exchange (ETDEWEB)

    Hampel, G.; Grunewald, C.; Schutz, C.; Schmitz, T.; Kratz, J.V. [Nuclear Chemistry, University of Mainz, D-55099 Mainz (Germany); Brochhausen, C.; Kirkpatrick, J. [Department of Pathology, University of Mainz, D-55099 Mainz (Germany); Bortulussi, S.; Altieri, S. [Department of Nuclear and Theoretical Physics University of Pavia, Pavia (Italy); National Institute of Nuclear Physics (INFN) Pavia Section, Pavia (Italy); Kudejova, P. [Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II), Technische Universitaet Muenchen, D-85748 Garching (Germany); Appelman, K.; Moss, R. [Joint Research Centre (JRC) of the European Commission, NL-1755 ZG Petten (Netherlands); Bassler, N. [University of Aarhus, Norde Ringade, DK-8000, Aarhus C (Denmark); Blaickner, M.; Ziegner, M. [Molecular Medicine, Health and Environment Department, AIT Austrian Institute of Technology GmbH (Austria); Sharpe, P.; Palmans, H. [National Physical Laboratory, Teddington TW11 0LW, Middlesex (United Kingdom); Otto, G. [Department of Hepatobiliary, Pancreatic and Transplantation Surgery, University of Mainz, D-55099 Mainz (Germany)

    2011-07-01

    The thermal column of the TRIGA reactor in Mainz is being used very effectively for medical and biological applications. The BNCT (boron neutron capture therapy) project at the University of Mainz is focussed on the treatment of liver tumours, similar to the work performed in Pavia (Italy) a few years ago, where patients with liver metastases were treated by combining BNCT with auto-transplantation of the organ. Here, in Mainz, a preclinical trial has been started on patients suffering from liver metastases of colorectal carcinoma. In vitro experiments and the first animal tests have also been initiated to investigate radiobiological effects of radiation generated during BNCT. For both experiments and the treatment, a reliable dosimetry system is necessary. From work elsewhere, the use of alanine detectors appears to be an appropriate dosimetry technique. (author)

  12. Dosage of boron traces in graphite, uranium and beryllium oxide

    International Nuclear Information System (INIS)

    Coursier, J.; Hure, J.; Platzer, R.

    1955-01-01

    The problem of the dosage of the boron in the materials serving to the construction of nuclear reactors arises of the following way: to determine to about 0,1 ppm close to the quantities of boron of the order of tenth ppm. We have chosen the colorimetric analysis with curcumin as method of dosage. To reach the indicated contents, it is necessary to do a previous separation of the boron and the materials of basis, either by extraction of tetraphenylarsonium fluoborate in the case of the boron dosage in uranium and the beryllium oxide, either by the use of a cations exchanger resin of in the case of graphite. (M.B.) [fr

  13. RA Research reactor Annual report 1982 - Part 1, Operation, maintenance and utilization of the RA reactor; Istrazivacki nuklearni reaktor RA - Deo 1 - Pogon, odrzavanje i eksploatacija nuklearnog reaktora RA u 1982. godini

    Energy Technology Data Exchange (ETDEWEB)

    Sotic, O; Martinc, R; Kozomara-Maic, S; Cupac, S; Radivojevic, J; Stamenkovic, D; Skoric, M; Miokovic, J [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1982-12-15

    Reactor test operation started in September 1981 at 2 MW power with 80% enriched fuel continued during 1982 according to the previous plan. The initial reactor core was made of 44 fuel channel each containing 10 fuel slugs. The first half of 1982 was used for the needed measurements and analysis of operating parameters and functioning of reactor systems and equipment under operating conditions. Program concerned with the testing operation at higher power levels was started in the second half of this year. It was found that the inherent excess reactivity and control rod worths ensure safe operation according to the IAEA safety standards. Excess reactivity is high enough to enable higher power level of 4.7 MW during 4 monthly cycles each lasting 15-20 days. Favourable conditions for cooling exist for the initial core configuration. Effects of poisoning at startup on the reactivity and power density distribution were measured as well as initial spatial distribution of the neutron flux which was 3,9 10{sup 13} cm{sup -2} s{sup -1} at 2 MW power. Modification of the calibration coefficient in the system for automated power level control was determined. All the results show that all the safety criteria and limitations concerned with fuel utilization are fulfilled if reactor power would be 4.7 MW. Additional testing operation at 3, 4, and 4.7 MW power levels will be needed after obtaining the licence for operating at nominal power. Transition from the initial core with 44 fuel channels to the equilibrium lattice configuration with 72 fuel channels each containing 10 fuel slugs, would be done gradually. Reactor was not operated in September because of the secondary coolant pipes were exchanged between Danube and the horizontal sedimentary. Control and maintenance of the reactor equipment was done regularly and efficiently dependent on the availability of the spare parts. Difficulties in maintenance of the reactor instrumentation were caused by unavailability of the

  14. A comparative study of two digestion methods employed for the determination boron in ferroboron used as an advanced shielding material

    International Nuclear Information System (INIS)

    Kamble, Granthali S.; Manisha, V.; Venkatesh, K.

    2015-01-01

    Shielding of nuclear reactor core is an important requirement of fast reactors. An important objective of future Fast Breeder Reactors (FBRs) is to reduce the volume of shields. A large number of materials have been considered for use to reduce the neutron flux to acceptable levels. A shield material which brings down the energy of neutrons by elastic and inelastic scattering along with absorption will be more effective. Ferro boron is identified as one of the advanced shielding materials considered for use in future FBRs, planned to be constructed in India. Ferroboron is an economical and indigenously available material which qualifies as a promising shield material through literature survey and scoping calculations. Experiments have been conducted in KAMINI reactor to understand the effectiveness of prospective shield material Ferro-boron as an in-core shield material for future FBRs. The Ferro boron used in these experiments contained 11.8% and 15% of boron. Precise determination of boron content in these ferro boron samples is very important to determine its effectiveness as a shield material. In this work a comparative study was carried out to determine the boron content in ferro boron samples. In the first method the sample was treated with incremental amounts of nitric acid under reflux (to prevent rigorous reaction and volatalisation of boron). The solution was gradually heated and the solution was filtered through a Whatman Filter paper no. 41. The undissolved ferro boron residue collected in the filter paper after filtration, is transferred to a platinum crucible; mixed with sodium carbonate and is ashed. The crucible is placed over a burner for 1 h to fuse the contents. The fused mass is leached in dilute hydrochloric acid, added to the nitric acid filtrate and made up to pre-determined volume

  15. Determination of microdistribution of boron in metals

    Energy Technology Data Exchange (ETDEWEB)

    Illic, R; Najzer, M; Rant, J [J. Stefan Institute, Ljubljana (Yugoslavia)

    1976-07-01

    A neutron induced autoradiographic technique was used for the determination of the boron microdistribution in metals. The specimens, which were in close contact with a LR 115 SSTD, were irradiated in the exposure room of the TRIGA Mark II reactor in Ljubljana. The spatial resolution of the autoradiographic image recorded by the LR 115 detector was found to be influenced mainly by the size of the reaction product tracks. The track diameter of a normally etched detector was about 7 {mu}m. An appreciable reduction of track size was achieved by pre-etching the detector foil before neutron irradiation. By this procedure it was possible to obtain a track diameter as small as 1 {mu}m and correspondingly to improve the spatial resolution of the autoradiographs of type EC 80 steel and Al Mg 3 alloy which contain 30 and 2 ppm of boron respectively. (author)

  16. Study of "2"2"3Ra uptake mechanism by Fe_3O_4 nanoparticles: towards new prospective theranostic SPIONs

    International Nuclear Information System (INIS)

    Mokhodoeva, Olga; Vlk, Martin; Málková, Eva; Kukleva, Ekaterina; Mičolová, Petra; Štamberg, Karel; Šlouf, Miroslav; Dzhenloda, Rustam; Kozempel, Ján

    2016-01-01

    The use of superparamagnetic iron oxide nanoparticles (SPIONs) and radiolabelled nanoparticles (NPs) has grown considerably over the recent years, and the SPIONs labelled with medicinal radionuclides offer new opportunities in multimodal diagnostics and in the drug-delivery systems for targeted alpha-particle therapy (TAT) driven by magnetic field gradient or by biologically active moieties bound on NPs shell. However, the mechanisms of NPs radiolabelling are not studied substantially and still remain unclear, even though the way of label attachment directly implies the stability of the label-nanoparticle construct. Since the "2"2"3Ra was the first clinically approved alpha-emitter, it is a promising nuclide for further development of its targeted carriers. We report here on the study of "2"2"3Ra uptake by the Fe_3O_4SPIONs, together with an attempt to propose the "2"2"3Ra uptake mechanism by the Fe_3O_4NPs in the presence of a phosphate buffer a typical formulation medium, under the pseudo-equilibrium conditions. Further, the in vitro stability tests of the prepared ["2"2"3Ra]Fe_3O_4NPs were performed to estimate the "2"2"3Ra label stability. The potential use of "2"2"3Ra-labelled SPIONs in theranostic applications is also discussed.Graphical abstract

  17. Boron-enhanced diffusion of boron from ultralow-energy boron implantation

    International Nuclear Information System (INIS)

    Agarwal, A.; Eaglesham, D.J.; Gossmann, H.J.; Pelaz, L.; Herner, S.B.; Jacobson, D.C.

    1998-01-01

    The authors have investigated the diffusion enhancement mechanism of BED (boron enhanced diffusion), wherein the boron diffusivity is enhanced three to four times over the equilibrium diffusivity at 1,050 C in the proximity of a silicon layer containing a high boron concentration. It is shown that BED is associated with the formation of a fine-grain polycrystalline silicon boride phase within an initially amorphous Si layer having a high B concentration. For 0.5 keV B + , the threshold implantation dose which leads to BED lies between 3 x 10 14 and of 1 x 10 15 /cm -2 . Formation of the shallowest possible junctions by 0.5 keV B + requires that the implant dose be kept lower than this threshold

  18. Boron mixing transients in a 900 MW PWR vessel for a reactor start-up operation

    International Nuclear Information System (INIS)

    Alvarez, D.; Martin, A.; Schneider, J.P.

    1995-01-01

    In 1991 a R and D action, based on numerical simulations and experiments on PWRs'S primary coolant temperature or boron mixing capabilities, was initiated. This paper presents the test facility BORA-BORA (a 1/5th scaled mock-up of a 900 MW PWR vessel) and the Thermalhydraulic Finite Element Code N3S used for 3D calculations performed on the accurate geometry of the plant. As a validation test case of these experimental and numerical tools, we present the results obtained on the primary coolant mixing capabilities in the vessel with the three loops balanced in mass flow rate. The second part of this report deals with the mixing of a clear water plug in the vessel when a primary coolant pump start-up. The results are obtained in the mock-up in terms of boron concentration at the core inlet for several clear water plug volumes. The numerical results give the complete fluid flow and boron concentration patterns but comparisons were made at the core inlet. (author). 15 refs., 9 figs., 1 tab

  19. Highly thermal conductive carbon fiber/boron carbide composite material

    International Nuclear Information System (INIS)

    Chiba, Akio; Suzuki, Yasutaka; Goto, Sumitaka; Saito, Yukio; Jinbo, Ryutaro; Ogiwara, Norio; Saido, Masahiro.

    1996-01-01

    In a composite member for use in walls of a thermonuclear reactor, if carbon fibers and boron carbide are mixed, since they are brought into contact with each other directly, boron is reacted with the carbon fibers to form boron carbide to lower thermal conductivity of the carbon fibers. Then, in the present invention, graphite or amorphous carbon is filled between the carbon fibers to provide a fiber bundle of not less than 500 carbon fibers. Further, the surface of the fiber bundle is coated with graphite or amorphous carbon to suppress diffusion or solid solubilization of boron to carbon fibers or reaction of them. Then, lowering of thermal conductivity of the carbon fibers is prevented, as well as the mixing amount of the carbon fiber bundles with boron carbide, a sintering temperature and orientation of carbon fiber bundles are optimized to provide a highly thermal conductive carbon fiber/boron carbide composite material. In addition, carbide or boride type short fibers, spherical graphite, and amorphous carbon are mixed in the boron carbide to prevent development of cracks. Diffusion or solid solubilization of boron to carbon fibers is reduced or reaction of them if the carbon fibers are bundled. (N.H.)

  20. Nuclear Design Study for Reduced Boron Concentration Operation

    International Nuclear Information System (INIS)

    Daing, Aung Tharn; Kim, Myung Hyun

    2008-01-01

    In PWR, Boron Dilution Accident (BDA) which is an inadvertent reduction of the soluble boron concentration in the primary coolant, can lead to a positive reactivity insertion and a power increase. In this study, an optimal Low Boron Concentration (LBC) core design will be developed by reducing an excess reactivity so as to possess passive inherently safety features as well as one of attentively preventive measures of BDA scenarios. The scope of the research project concerning the change of operational procedure in chemical shim system, will involve three main parts namely, nuclear design for LBC core, feasibility check on the proposed core in safety and costs, and PSA approach on design change benefits. In addition, successful system analysis of the reactivity effects due to boron dilution transients, require a full coupling between core thermal hydraulic, reactor dynamics, and the use of Computational Fluid Dynamics (CFD) codes

  1. Nuclear Design Study for Reduced Boron Concentration Operation

    Energy Technology Data Exchange (ETDEWEB)

    Daing, Aung Tharn; Kim, Myung Hyun [Kyung Hee University, Yongin (Korea, Republic of)

    2008-10-15

    In PWR, Boron Dilution Accident (BDA) which is an inadvertent reduction of the soluble boron concentration in the primary coolant, can lead to a positive reactivity insertion and a power increase. In this study, an optimal Low Boron Concentration (LBC) core design will be developed by reducing an excess reactivity so as to possess passive inherently safety features as well as one of attentively preventive measures of BDA scenarios. The scope of the research project concerning the change of operational procedure in chemical shim system, will involve three main parts namely, nuclear design for LBC core, feasibility check on the proposed core in safety and costs, and PSA approach on design change benefits. In addition, successful system analysis of the reactivity effects due to boron dilution transients, require a full coupling between core thermal hydraulic, reactor dynamics, and the use of Computational Fluid Dynamics (CFD) codes.

  2. External irradiation of the personnel operating the reactor RA at Vinca in the period 1963-1966; Spoljasnje ozracivanje osoblja koje opsluzuje reaktor RA u Vinci u periodu od 1963. do 1966. godine

    Energy Technology Data Exchange (ETDEWEB)

    Ninkovic, M M; Minincic, Z [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1968-06-15

    The paper first gives a survey of the characteristic operations performed on the Vinca reactor RA in which most of the personnel become irradiated. Following is a schematic diagram of the irradiations in the period 1963-1966 in which the reactor was in continual operation. The surveys are given for each month and each year separately, while the irradiated personnel are grouped in several characteristic irradiation dose ranges. In this analysis special emphasis is given to a survey of irradiation of the personnel classified according to their profession, i.e. their post. This kind of analysis is indispensable in planning work, proper disposition of the personnel and undertaking special protective measures for reducing the irradiations (author) [Serbo-Croat] U radu je najpre dat pregled mesta na reaktoru RA, sa topografijom zracenja, na kojima radno osoblje pretezno biva ozracivano. Zatim su dati tabelarno i graficki pregledi ozracivanja za protekli period u kome je reaktor neprekidno radio, tj. od 1963. do 1966. god. Pregledi su dati po mesecima za svaku godinu i to tako sto su ozracivana lica razvrstavana u nekoliko karakteristicnih intervala doza ozracivanja. Posebno mesto u ovoj analizi zauzima pregled ozracivanja osoblja razvrstanog po strukama, odnosno radnim mestima. Ovakva analiza je nuzna za planiranje poslova, pravilan raspored radnog osoblja kao i preduzimanje posebnih zastitnih mera u cilju smanjivanja ozracivanja (author)

  3. Coolant mixing in pressurized water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hoehne, T; Grunwald, G

    1998-10-01

    The behavior of PWRs during cold water or boron dilution transients is strongly influenced by the distribution of coolant temperature and boron concentration at the core inlet. This distribution is the needed input to 3-dimensional neutron kinetics to calculate the power distribution in the core. It mainly depends on how the plugs of cold or unborated water formed in a single loop are mixed in the downcomer and in the lower plenum. To simulate such mixture phenomena requires the application of 3-dimensional CFD (computational fluid dynamics) codes. The results of the simulation have to be validated against mixture experiments at scaled facilities. Therefore, in the framework of a research project funded by BMBF, the institute creates a 1:5 mixture facility representing first the geometry of a German pressurized water reactor and later the European Pressurized Water Reactor (EPR) geometry. The calculations are based on the CFD Code CFX-4. (orig.)

  4. Annex VII - Diagrams: 1. Reactor operation (1960-1977); 2. Mean daily reactor power density in 1977; 3. Monthly reactor power for 1977; 4. percent of utilization of experimental space in 1977; Prilog VII - Dijagrami: 1. Rad reaktora (MWh) po godinama (1960-1977); 2. Srednja dnevna snaga reaktora u 1977. godini; 3. Rad reaktora (MWh) po mesecima za 1977. godinu i 4. Procenat iskoriscenja eksperimentalnog prostora u 1977. godini

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1977-12-15

    This Annex includes the following diagrams: 1. Annual Reactor RA power production (MWh) for the period from 1960-1977; 2. Mean daily reactor power density MW in 1977; 3. Monthly reactor power production (MWh) for 1977; 4. percent of utilization of experimental space in 1977. [Serbo-Croat] Ovaj prilog sadrzi dijagrame: 1. Rad reaktora (MWh) po godinama (1960-1977); 2. Srednja dnevna snaga reaktora u 1977. godini; 3. Rad reaktora (MWh) po mesecima za 1977. godinu i 4. Procenat iskoriscenja eksperimentalnog prostora u 1977. godini.

  5. The effect of boron additions on irradiation-induced order changes in Ni3Al intermetallic compounds

    International Nuclear Information System (INIS)

    Njah, N.; Gilbon, D.; Dimitrov, O.

    1995-01-01

    The effects of boron additions (0.1 wt%) on the kinetics of atomic order changes in a Ni 76 Al 24 intermetallic compound, under 1 MeV electron irradiation, were investigated at temperatures of 293 K and 410 K and displacement rates of 0.09 x 10 -3 to 4.7 x 10 -3 dpa.s -1 . In these irradiation conditions, a state of residual order was obtained for long irradiation times, characterized by a steady state order parameter S∞; it corresponds to a competition between two opposite features: irradiation disordering and thermal reordering enhanced by irradiation. Boron additions did not affect the efficiency of irradiation-induced disordering: the disordering cross-section (or, equivalently, the number of replacements per displacement var-epsilon) were comparable with and without a boron addition. By contrast, the S∞ values at 293 K were much lower in the alloy containing boron. Since boron does not change the disordering rate, the large difference between the values obtained in undoped and in boron-doped alloys shows that the reordering rate is strongly reduced by the presence of boron. Thus, boron modifies the mobility of the defects responsible for the irradiation-enhanced diffusion. The data on dislocation-loop size and the reordering kinetics suggest that vacancies are trapped by boron at low temperatures and immobilized, probably by the formation of a boron-vacancy complex. The effect becomes weaker at higher displacement rates and higher temperatures, probably due to the boron-vacancy complexes becoming unstable. It is proposed that two different reordering mechanisms may be operative at 293 K, according to the presence of boron: reordering is promoted by vacancy migration in the Ni 76 Al 24 alloy, whereas in the Ni 76 Al 24 (0.1 wt%B) alloy, it is promoted by the migration of split-interstitials or/and of low-mobility vacancy-boron complexes

  6. Analysis of dynamic stability and safety of reactor system by reactor simulator; Analiza dinamicke stabilnosti i sigurnosti reaktorskog sistema pomocu reaktorskog simulatora

    Energy Technology Data Exchange (ETDEWEB)

    Raisic, N [Boris Kidric Institute of Nuclear Sciences Vinca, Belgrade (Yugoslavia)

    1963-11-15

    In order to enable qualitative analysis of dynamic properties of reactors RA and RB, mathematical models of these reactors were formulated and adapted for solution on analog computer. This report contains basic assessments for creating the model and complete equations for each reactor. Model was used to analyse three possible accidents at the RA reactor and possible hypothetical accidents at the RB reactor.

  7. The intergranular segregation of boron in substoichiometric Ni/sub 3/Al

    Energy Technology Data Exchange (ETDEWEB)

    Choudhury, A.

    1987-12-01

    The intermetallic compound Ni/sub 3/Al offers promise as a material for high temperature applications. In addition to its unusual property of increasing strength with temperature (until approx.700/sup 0/C), it has excellent corrosion and oxidation resistance. Microalloying the alloy with boron has been shown to be dramatically effective in improving its inherent intergranular brittleness. This improvement results from the strong tendency of boron to segregate to the grain boundaries of Ni/sub 3/Al. This research deals with the study of the segregation behavior of boron. Auger electron spectroscopy was chosen as the technique adopted to study this segregation. The strong effect of segregant level on the grain boundary strength level can be controlled by thermal history variations and by variations in the level of solute in the bulk. Cathodic hydrogen charging was shown to be a potent tool in opening up other wise cohesive boundaries for analysis. The effective binding energy of boron at the grain boundaries of Ni/sub 3/Al was calculated from experimental data; it was found to vary between 0.2 and 0.45 eV. Kinetics of segregation have been investigated; the present set of kinetic studies were shown to be inadequate to find a diffusion coefficient and that temperatures lower than those studied here need to be used. As an associated investigation, a set of elemental standards were developed for the particular scanning Auger microprobe used in this study. 141 refs., 94 figs., 26 tabs.

  8. Boron analysis for neutron capture therapy using particle-induced gamma-ray emission

    International Nuclear Information System (INIS)

    Nakai, Kei; Yamamoto, Yohei; Okamoto, Emiko; Yamamoto, Tetsuya; Yoshida, Fumiyo; Matsumura, Akira; Yamada, Naoto; Kitamura, Akane; Koka, Masashi; Satoh, Takahiro

    2015-01-01

    The neutron source of BNCT is currently changing from reactor to accelerator, but peripheral facilities such as a dose-planning system and blood boron analysis have still not been established. To evaluate the potential application of particle-induced gamma-ray emission (PIGE) for boron measurement in clinical boron neutron capture therapy, boronophenylalanine dissolved within a cell culture medium was measured using PIGE. PIGE detected 18 μgB/mL f-BPA in the culture medium, and all measurements of any given sample were taken within 20 min. Two hours of f-BPA exposure was required to create a boron distribution image. However, even though boron remained in the cells, the boron on the cell membrane could not be distinguished from the boron in the cytoplasm. - Highlights: • PIGE was evaluated for measuring blood boron concentration during clinical BNCT. • PIGE detected 18 μgB/mL f-BPA in culture medium. • All measurements of any given sample were taken within 20 min. • Two hours of f-BPA exposure is required to create boron distribution image by PIGE. • Boron on the cell membrane could not be distinguished from boron in the cytoplasm.

  9. Thermodynamical and thermoelectric properties of boron doped YPd{sub 3} and YRh{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Dwivedi, Shalini; Sharma, Yamini, E-mail: sharma.yamini62@gmail.com [Theoretical Condensed Matter Physics Laboratory, Dept. of Physics, Feroze Gandhi College, Raebareli-229001 U.P (India); Sharma, Ramesh [Dept. of Physics, Mewar University, Chittorgarh-312901 Rajasthan (India)

    2016-05-23

    The structural, electronic, thermal, and optical properties of borides of cubic non-magnetic YX{sub 3} (X=Rh, Pd) compounds and their borides which crystallize in the AuCu{sub 3} structure have been studied using the density functional theory (DFT). The flat bands in the vicinity of E{sub F} which are associated with superconductivity appear in YPd{sub 3} and YRh{sub 3} band structures. However, the B s-states enhance the flat band only in YRh{sub 3}B. The optical properties clearly show that boron insertion modifies the absorption and transmittance. The YX{sub 3} alloys and their borides exhibit valuable changes in the thermopower and ZT. It is observed that the properties of the Y-X intermetallics change significantly for the Y-Rh and Y-Pd alloys and the presence of single boron atom modifies the properties to a great extent.

  10. The study of high-boron steel and high-boron cast iron used for shield

    International Nuclear Information System (INIS)

    Pan Xuerong; Lu Jixin; Wen Yaozeng; Wang Zhaishu; Cheng Jiantin; Cheng Wen; Shun Danqi; Yu Jinmu

    1996-12-01

    The smelting, forging, heat-treatment technology and the mechanical properties of three kinds of high-boron steels (type 1: 0.5% boron; type 2: 0.5% boron and 4% or 2% nickel; type 3: 0.5% boron, 0.5% nickel and 0.5% molybdenum) were studied. The test results show that the technology for smelting, forging and heat-treatment (1050 degree C/0.5 h water cooled + 810 degree C/1 h oil cooled) in laboratory is feasible. Being sensitive to notch, the impact toughness of high-boron steel type 1 is not steady and can not meet the technology requirements on mechanical properties. The mechanical properties of both high-boron steel type 2 and type 3 can meet the technological requirements. The smelting technology of high-boron casting iron containing 0.5% boron was researched. The tests show that this casting iron can be smelted in laboratory and its properties can basically satisfy the technology requirements. (10 refs., 6 figs., 11 tab.)

  11. Anesthetic management of Boron Neutron Capture Therapy for glioblastoma

    International Nuclear Information System (INIS)

    Shinomura, T.; Furutani, H.; Osawa, M.; Ono, K.; Fukuda, K.

    2000-01-01

    General anesthesia was given to twenty-seven patients who received Boron Neutron Capture Therapy (BNCT) under craniotomy at Kyoto University Research Reactor from 1991 to 1999. Special considerations are required for anesthesia. (author)

  12. Comparison of product selectivity during hydroprocessing of bitumen derived gas oil in the presence of NiMo/Al{sub 2}O{sub 3} catalyst containing boron and phosphorus

    Energy Technology Data Exchange (ETDEWEB)

    D. Ferdous; A.K. Dalai; J. Adjaye [University of Saskatchewan, SK (Canada). Catalysis and Chemical Reactor Engineering Laboratories, Department of Chemical Engineering

    2006-06-15

    A detailed experimental study was performed in a trickle-bed reactor using bitumen derived gas oil. The objective of this work was to compare the activity of NiMo/Al{sub 2}O{sub 3} catalyst containing boron or phosphorus for the hydrotreating and mild hydrocracking of bitumen derived gas oil. Experiments were performed at the temperature and LHSV of 340-420{sup o}C and 0.5-2 h{sup -1}, respectively, using NiMo/Al{sub 2}O{sub 3} catalysts containing 1.7 wt% boron or 2.7 wt% phosphorus. In the temperature range of 340-390{sup o}C, higher nitrogen conversion was observed from boron containing catalyst than that from phosphorus containing catalyst whereas in the same temperature range, phosphorus containing catalyst gave higher relative removal of sulfur than boron containing catalyst. Phosphorus containing catalyst showed excellent hydrocracking and mild hydrocracking activities at all operating conditions. Higher naphtha yield and selectivity were obtained using phosphorus containing catalyst at all operating conditions. Maximum gasoline selectivity of {approximately}45 wt% was obtained at the temperature, pressure, and LHSV of 400{sup o}C, 9.4 MPa and 0.5 h{sup -1}, respectively, using catalyst containing 2.7 wt% phosphorus. 40 refs., 13 figs., 1 tab.

  13. Measurement of gamma radiation doses at the RA reactor by thermoluminescent dosemeters

    International Nuclear Information System (INIS)

    Prokic, M.

    1974-01-01

    This paper presents the procedures and gamma radiation doses measured at the exit from the horizontal experimental channel HK-5, vertical experimental channel VK-5 and in the thermal column of the RA reactor in Vinca. Measurement of gamma radiation dose in the mixed intense gamma and neutron radiation field was done by two types of thermoluminescent dosemeters, LiF (TLD-700) and CaF 2 (TLD-08). Gamma dose in the VK-5 was measured in the air and on the bottle filled with tissue-equivalent solution. Increase of the dose on the surface of the bottle was 2.3 compared to the gamma dose value in the air. Correction for the influence of neutrons having different energies was done by using the known sensitivity values of both TL dosemeter types for thermal, intermediate and fast neutrons. Results showed that the TLD-700 dosemeter contains 5 time more Li-6 isotopes (0.035%) than the declared value causing increased neutron sensitivity of this dosemeter. This paper includes numerical sensitivity data for neutrons of different energies for both types of TL dosemeters. Neutron sensitivity values for TLD-700 are related to LiF with 0.035% of Li-6 isotope. Result of measurement have also shown that the CaF 2 :Mn (TLD-08) thermoluminescent dosemeter is more suitable for gamma radiation dose measurements in mixed n-gamma fields with intensive neutron fluxes due to lower neutron sensitivity compared to TLD-700 [sr

  14. Boronic species as promising inhibitors of the Staphylococcus aureus NorA efflux pump: study of 6-substituted pyridine-3-boronic acid derivatives.

    Science.gov (United States)

    Fontaine, Fanny; Héquet, Arnaud; Voisin-Chiret, Anne-Sophie; Bouillon, Alexandre; Lesnard, Aurélien; Cresteil, Thierry; Jolivalt, Claude; Rault, Sylvain

    2015-05-05

    In response to the extensive use of antibiotics, bacteria have evolved numerous mechanisms of defense against antimicrobial agents. Among them, extrusion of the antimicrobial agents outside the bacterial cell through efflux pumps is a major cause of concern. At first limited to one or few structurally-related antibiotics, bacterial resistance have then progressed towards cross-resistance between different classes of antibiotics, leading to multidrug-resistant microorganisms. Emergence of these pathogens requires development of novel therapeutic strategies and inhibition of efflux pumps appears to be a promising strategy that could restore the potency of existing antibiotics. NorA is the most studied chromosomal efflux pump of Staphylococcus aureus; it is known to be implied in resistance of Methicillin-resistant S. aureus (MRSA) strains against a wide range of unrelated substrates, including hydrophilic fluoroquinolones. Starting from 6-benzyloxypyridine-3-boronic acid I that we previously identified as a potential inhibitor of the NorA efflux pump against the NorA-overexpressing S. aureus 1199B strain (SA1199B), we describe here the synthesis and biological evaluation of a series of 6-(aryl)alkoxypyridine-3-boronic acids. 6-(3-Phenylpropoxy)pyridine-3-boronic acid 3i and 6-(4-phenylbutoxy)pyridine-3-boronic acid 3j were found to potentiate ciprofloxacin activity by a 4-fold increase compared to the parent compound I. In addition, it has been shown that both compounds promote Ethidium Bromide (EtBr) accumulation in SA1199B, thus corroborating their potential mode of action as NorA inhibitors. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  15. Activity report on the utilization of research reactors (JRR-3 and JRR-4). Japanese fiscal year, 2008

    International Nuclear Information System (INIS)

    2014-02-01

    JRR-3 is used for the purposes below; Experimental studies such as neutron scattering, prompt gamma-ray analyses, neutron radiography, Irradiation for activation analyses, radioisotope (RI) productions, fission tracks, Irradiation test of reactor materials, etc. JRR-4 is used for the purposes below; Medical irradiation (Boron Neutron Capture Therapy : BNCT), Prompt gamma-ray analyses, Sensitivity measurement of radiation detectors, Experiment and practice in the nuclear reactor training, Irradiation for activation analyses, RI productions, fission tracks etc. In the fiscal year 2008, the research reactor JRR-3 was operated for 7 cycles (cycle operation : 26days/cycle) for utilization sharing of facility. The research reactor JRR-4 was not operated in 2008. Because a crack was found on the weld of the aluminum cladding of a graphite reflector element. JRR-4 has remained shutdown until the reflector elements were replaced. The volume contains 250activity reports, which are categorized into the fields of neutron scattering (11 subcategories), neutron radiography, neutron activation analyses, and others submitted by the users in JAEA and other Organizations. (author)

  16. Radiation protection at the RA Reactor in 1996, Part -2, Annex 1, Control of the working environment, dosimetry and radiation protection; Prilog 1 - Zastita od zracenja kod reaktora RA u 1996. godini - Deo 2 - Kontrola radne sredine - dozimetrija i tehnicka zastita kod reaktora RA

    Energy Technology Data Exchange (ETDEWEB)

    Pavlovic, R; Kalinic, S [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1996-12-01

    This report contains data and analysis of the of measured sample results collected during radiation protection control in the working environment of the RA reactor. First part contains basic exposure values and statistical review of the the total number of radiation measurements. It includes contents of radioactive gasses and effluents in the air, as well as the level of surface contamination of clothes and uncovered parts of the personnel bodies. Second part deals with the analysis of personnel doses. Third part of this annex contains basic data about the quantity of collected radioactive waste, total quantity of contaminated and decontaminated surfaces. Previously initiated actions concerning future decision on the status of the RA reactor were continued during 1996. Actions in 1996 were focused to detailed analysis of the conditions of storing the spent fuel in the storage pools and preparing the documentation for decision making about the methods for the improvement of the mentioned conditions. It is stated that there have been no accidents that could cause significant contamination of working surfaces and components nor radiation exposure of the personnel. [Serbo-Croat] U ovom izvestaju prikazani su i analizirani reprezentativni rezultati sakupljeni u okviru kontrole radne sredine i tehnicke zastite od zracenja reaktora RA. U prvom delu izvestaja izlozeni su podaci o osnovnim vidovima izlaganja zracenju i statisticki pregled ukupnog broja radijacionih merenja. Dati su takodje rezultati merenja sadrzaja radioktivnih gasova i aerosola u vazduhu, kao i stepena kontaminacije povrsina, odece i otkrivenih delova tela osoblja. U drugom delu izvestaja izlozeni su rezultati analize ozracivanja radnog osoblja. U trecem delu izvestaja navedeni su osnovni podaci o ukupnim kolicinama sakupljenog radioaktivnog materijala, ukupnoj velicini kontaminiranih i dekontaminiranih povrsina i broju dekontaminiranih predmeta. U 1996. godini nastavljena je akcija zapoceta prethodne

  17. Determination of sup 226 Ra and sup 228 Ra in gypsum

    Energy Technology Data Exchange (ETDEWEB)

    Godoy, J M [Instituto de Radioprotecao e Dosimetria, Rio de Janeiro, RJ (Brazil)

    1989-01-01

    The content of {sup 226}Ra and {sup 228}Ra in different samples of phosphogypsum and three samples of gypsite were determined by gamma spectroscopy. For {sup 226}Ra the 295, 352 and 609 KeV lines and for {sup 228}Ra the 911 and 969 KeV lines were used. The specific activities values ranged from 0.36 to 22.8 pCi/g for {sup 226}Ra and 0.90 to 10.3 pCi/g for {sup 228}Ra. The contribution of a sypsum roof-covering to the {sup 222}Rn concentration in a room was estimated, based on the highest value reported. (author).

  18. Boron-doped hydrogenated Al{sub 3} clusters: A material for hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Muz, İskender, E-mail: iskender.muz@nevsehir.edu.tr [Faculty of Education, Department of Science Education, Nevsehir Haci Bektas Veli University, 50300, Nevsehir (Turkey); Atiş, Murat [Kayseri Vocational School, Electricity and Energy Department, Erciyes University, 38300, Kayseri (Turkey)

    2016-05-15

    The energetic and structural stabilities of Al{sub 3}BH{sub 2n} (n = 0–6) clusters are investigated using ab initio calculations. Structural isomers are found using the stochastic search method to search for minima structures, followed by B3LYP optimizations; single-point CCSD(T) calculations are performed to compute relative energies. Chemical bonding analysis is also performed using the adaptive natural density partitioning method to investigate the chemical bonding in the clusters and to elucidate their structural evolution. Our results and analyses indicate that the stability of the boron-doped hydrogenated Al{sub 3} clusters increases as more hydrogen molecules are adsorbed, whereas the H{sub 2} loss energy decreases. The results are in good agreement with available theoretical findings. - Highlights: • The boron-doped hydrogenated Al{sub 3} clusters are generated using stochastic search method. • The energetic and structural stabilities are investigated in detail. • The chemical bonding analysis is performed by using AdNDP analysis. • The doping by boron allows development of better aluminum-based metal hydrides.

  19. Note on boron toxicity in oats

    Energy Technology Data Exchange (ETDEWEB)

    Langille, W M; Mahoney, J F

    1959-01-01

    Boron was applied at the rate of 35 pounds per acre of borax to a field of oats. With the first noticeable growth there appeared a definite chlorotic condition of the oat seedlings on plots receiving boron treatments. Analysis of chlorotic tissue at 3 weeks after seeding indicated 110 ppm boron, while apparently healthy tissue contained 6.1 ppm boron at the same stage of growth. There was a rapid decline in the boron content of the oat tissue as the crop grew older. At maturity the oat tissue from the boron-treated plots contained an average of 14.15 ppm boron as compared with 4.10 boron from untreated areas. Boron toxicity had no harmful effect so far as yields were concerned, under the conditions of this experiment. 3 references.

  20. Radiation protection at the RA Reactor in 1993, Part II, Decontamination and actions, collection of liquid effluents and solid radioactive waste

    International Nuclear Information System (INIS)

    Mandic, M.; Vukovic, Z.; Lazic, S.; Plecas, I.; Voko, A.

    1993-01-01

    Certain amount of solid waste results from RA reactor operation, the mean quantity of which depends on the duration of reactor operation and related activities. During repair, when reactor is not operated as well under accidental conditions, the quantity of waste is higher, dependent on the type of repair and comprehensiveness of decontamination of the working surface, contaminated tools and components. The waste is sorted and packed on the spot where they appeared according to the existing regulations and principles of radiation protection with aim to minimize unnecessary exposure of the radiation protection personnel who deals with control, transport, radioactive waste treatment and decontamination. During exceptional operations (decontamination, repair, bigger volume of contaminated material, etc.) professional staff of the Radiation protection department gives recommendations and helps in planning the actions related to repair, sorting and packaging of radioactive waste in special containers, identification of the contaminants, etc. [sr