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

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.

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.

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.

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.

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

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.

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

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

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

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

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

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

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.

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.

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

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

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.

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

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)

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

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

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

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

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

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

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

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

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

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

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.

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

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

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

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)

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

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

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

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

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.

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)

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

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.

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

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.

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.

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.

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

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.

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

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.

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.

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.

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

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.

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.

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)

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.

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

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.

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)

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

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)

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

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

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

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

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

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

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.

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.

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

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

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

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

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.

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.

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

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

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.

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.

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.

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.

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

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.

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.

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)

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

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)

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

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

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

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)

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

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)

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

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

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.

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.

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

Completion of UO2 pellets production and fuel rods load for the RA-8 critical facility

International Nuclear Information System (INIS)

Marajofsky, Adolfo; Perez, Lidia E.; Thern, Gerardo G.; Altamirano, Jorge S.; Benitez, Ana M.; Cardenas, Hugo R.; Becerra, Fabian A.; Perez, Aldo E.; Fuente, Mariano de la

1999-01-01

The Advanced Fuels Division produced fuel pellets of 235 U with 1.8% and 3.6% enrichment and Zry-4 cladding loads for the RA-8 reactor at Pilcaniyeu Technological Unit. For economical and availability reasons, the powder acquired was initially UO 2 with 3.4% enrichment in 235 U, therefore the 235 U powder with 1.8% enrichment was produced by mechanical mixture. The production of fuel pellets for both enrichments was carried out by cold pressing and sintering processes in reducing atmosphere. The load of Zry-4 claddings was performed manually. The production stages can be divided into setup, qualification and production. This production allows not only to fulfill satisfactorily the new fuel rods supply for the RA-8 reactor but also to count with a new equipment and skilled personnel as well as to meet quality and assurance control methods for future pilot-scale production and even new fuel elements production. (author)

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)

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

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

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.

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

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.

Completion of UO{sub 2} pellets production and fuel rods load for the RA-8 critical facility; Finalizacion de la produccion de pastillas y carga de barras combustibles de UO{sub 2} para el conjunto critico RA-8

Energy Technology Data Exchange (ETDEWEB)

Marajofsky, Adolfo; Perez, Lidia E; Thern, Gerardo G; Altamirano, Jorge S; Benitez, Ana M; Cardenas, Hugo R; Becerra, Fabian A; Perez, Aldo E; Fuente, Mariano de la [Comision Nacional de Energia Atomica, General San Martin (Argentina). Dept. de Combustibles Nucleares

1999-07-01

The Advanced Fuels Division produced fuel pellets of {sup 235}U with 1.8% and 3.6% enrichment and Zry-4 cladding loads for the RA-8 reactor at Pilcaniyeu Technological Unit. For economical and availability reasons, the powder acquired was initially UO{sub 2} with 3.4% enrichment in {sup 235}U, therefore the {sup 235}U powder with 1.8% enrichment was produced by mechanical mixture. The production of fuel pellets for both enrichments was carried out by cold pressing and sintering processes in reducing atmosphere. The load of Zry-4 claddings was performed manually. The production stages can be divided into setup, qualification and production. This production allows not only to fulfill satisfactorily the new fuel rods supply for the RA-8 reactor but also to count with a new equipment and skilled personnel as well as to meet quality and assurance control methods for future pilot-scale production and even new fuel elements production. (author)

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

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

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.

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.

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)

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.

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

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

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

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

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.

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.

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.

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

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

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)

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)

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.

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

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

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.

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.

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.

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

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

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.

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

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)

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

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.

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

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

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.

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)

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.

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

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

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.

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

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.

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)

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.

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

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

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.

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.

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

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

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

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

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

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.

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

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

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

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

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

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)

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

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

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

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

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

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)

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

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

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.

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.

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}.

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

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)

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)

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)

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)

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)

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)

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)

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

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)

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.

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

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

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.

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)

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.

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.

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

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.

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).

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.

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.

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

Commissioning and start-up of RA-8 critical assembly

International Nuclear Information System (INIS)

Lorenzo, N. de; Diaz, C.; Facchini, G.; Fernandez, C.; Fittipaldi, A.; Juracich, R.; Levanon, I.; Manceda, J.; Martinez, J.; Mogdan, R.; Perez, J.; Scarnichia, E.; Blaumann, H.; Gennuso, G.; Scotti, G.

1999-01-01

The RA-8 critical assembly was designed as one of the experimental facilities for the CAREM Reactor Project. This paper describes the activities developed during the cold and hot commissioning, pointing out the difficulties and the solutions applied (some of them original ones). Moreover, this paper will show the main features of the newest nuclear installation of CNEA making a brief description of its characteristics. Among the special circumstances related to the commissioning that are described in the paper we can mention the following: 1. The facility shares the building with the Thermohydraulic Assay Laboratory (L.E.T.), another experimental facility of CAREM, and thus some shared systems have already been working for many years before this start up. Special procedures for these systems were designed to verify the proper functioning under the new requirements. 2. A new driving mechanism, based in hydraulic cylinders, was used to move the control rods. The criteria for acceptance and a validation of the procedure completeness have been carried out. 3. The implementation of a power measurement system based in neutron noise. 4. Measurement of Power Distribution using direct gamma counting from the fuel elements. 5. The commissioning was interrupted for a ten-month period because the personnel involved had to carry out the commissioning of the Egyptian Research Reactor 2. Also, the common activities during a commissioning are described, pointing out the major steps carried out and the results obtained. The following are examples of these activities: 1. Environmental dose survey (before fuel loading and during other stages). 2. Test of equipment and systems isolated from the rest of the plant. 3. Integrated system test (two or more systems working at the same time). 4. Start-up and power operation simulations before fuel loading. 5. Fuel loading strategy during the approximation to criticality by mass. 6. Modification of systems' components to improve the

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

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

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

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

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.

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.

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)

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)

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

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.

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

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.

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.

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)

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

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

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.

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)

Measurement of "2"2"6Ra and "2"2"8Ra in Brazilian and Israeli Phosphates

International Nuclear Information System (INIS)

Ferreira, W.; Canella Avelar, A.; Menezes, M.

2014-01-01

Since the 1970s, the IAEA recognizes that phosphoric acid presents an alternate source of uranium, but given the status of both phosphate and uranium markets the potential of recovering uranium from phosphoric acid still marginal. New technologies for the recovery of uranium from phosphoric acid, national and global interests and environment barriers could shape this market in the medium and long-term scenarios. On the other hand, the use of phosphates is the major source of phosphorus in agriculture and livestock. Beyond phosphorus and calcium, phosphate is also source of some hazardous elements, such: arsenic, cadmium, thorium and uranium, including a variety of radioisotopes as well. This radioactivity is sure to be released in the environment, contributing to the background. The risk is not recognized for some of the players in this market, mainly workers who apply phosphate fertilizers in the farmland, in some cases manipulating phosphates with their bare hands, and without any respiratory protection equipment (RPE) as well. This paper deals with the radioactivity from "2"2"6Ra and "2"2"8Ra in four phosphates often used in Brazilian agriculture. Three Brazilian and an Israeli phosphate were analysed and compared with international criteria. The specific activities of "2"2"6Ra (from the uranium decay series) and "2"2"8Ra (from the thorium decay series) were taken into consideration to ensure an adequate risk assessment. Specific activities were determined by high-resolution gamma spectroscopy with germanium detector and Genie® software from Canberra in the Centre of Nuclear Technology Development (CDTN/CNEN). The concentration of "2"2"6Ra was measured using the 186.2 keV energy peak, the concentration of "2"2"8Ra through "2"2"8Ac. The system was calibrated using a set of standard materials from IAEA. The measured samples were crushed and sieved to a grain (98% at least) size as small as 75 μm. Stable mass was achieved grinding, drying at 105°C and mixing

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'.

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)

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)

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)

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)

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.

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.

RA-8 brief description. Critical set for CAREM project

International Nuclear Information System (INIS)

Boado, H.; Girardi, A.

1990-01-01

A RA-8 critical set, intended to study the core's neutronic characteristics for the CAREM project, is described. The description is a design criteria synthesis of the plant's main systems, its use in the project and the experimental purposes to be reached. (Author) [es

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

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.

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

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

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.

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.

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

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.

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

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)

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.

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

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}.

Study of natural radionuclides - "2"2"6Ra, "2"2"8Ra and "2"1"0PB - in marine sediment cores from Southwest Atlantic during the Holocene

International Nuclear Information System (INIS)

Costa, Alice Miranda Ribeiro

2016-01-01

Natural radionuclides from "2"3"8U and "2"3"2Th series have been successfully applied as tracers of environmental process and climate changes. The "2"1"0Pb (half-life of 22.2 years) is used in the geochronological dating technique of sediment cores of the last 100-150 years, and its respective sedimentation rate determination. The study of "2"2"6Ra and "2"2"8Ra concentrations (half-lives of 1,600 years and 5.75 years, respectively) helps calculate the activity of "2"1"0Pb in excess in the environment, besides being important tracers of marine processes, as ground water discharge. In this work it was determined the activity concentrations of "2"2"6Ra, "2"2"8Ra and "2"1"0Pb in four short marine cores collected since the continental platform to upper slope of Southwest Atlantic Ocean. Taking into account the results obtained, sedimentation rates and the ages of each sediment layer were determined using the geochronological dating method with "2"1"0Pb. All sediment samples were total acid digested in microwave. The sequential radiochemical separation of "2"2"6Ra, "2"2"8Ra, "2"1"0Pb were performed, obtaining in the end the precipitation of Ba(Ra)SO_4 and PbCrO_4. The gross α measurements of "2"2"6Ra and gross β measurements of "2"2"8Ra and "2"1"0Pb from the precipitates were carried out in a gas-flow low background proportional counter. Concerning all cores analyzed, the activities concentrations of "2"2"6Ra ranged from 14 Bq.kg"-"1 to 154 Bq.kg"-"1; the concentrations of "2"2"8Ra ranged from 17 Bq.kg"-"1 to 45 Bq.kg"-"1; and the concentrations of "2"1"0Pb ranged from 20 Bq.kg"-"1 to 2,073 Bq.kg"-"1. High values of "2"1"0Pb were observed on the top of all the cores studied, mainly related to atmospheric deposition. The results obtained in this work were of the same order of magnitude of those reported in the literature available on non contaminated areas of Southeast Brazilian Coast. Sedimentation rates fall with the increase of water column depth and ranged from 0

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.

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

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.

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

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.

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

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.

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

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

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

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)

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

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.

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

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

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.

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.

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)

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.

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

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

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

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.

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.

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

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

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.

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

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)

Distribution of 226Ra and 228Ra in drinking water and dose assessment

International Nuclear Information System (INIS)

Ajay Kumar; Sugandhi, S.; Usha, N.; Rupali, K.; Gurg, R.P.

2002-01-01

The radioactivity concentrations of 226 Ra and 228 Ra have been analysed in 123 drinking water samples received from different regions of India. The maximum concentrations of 226 Ra and 228 Ra in drinking water are 8 mBq/l and 11.5 mBq/l respectively. The higher doses due to intake of 228 Ra through drinking water suggests that 228 Ra should also be measured in the assessment of ingestion dose to the population. The estimated committed effective doses range from 0.082 to 2.45 μSv/year and from 1.53 to 8.81 μSv/year for the ingestion of 226 Ra and 228 Ra respectively. (author)

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

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

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)

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)

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

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

Radiation protection at the RA Reactor in 1985, Part -2, Annex 1, Radioactivity control of working environment, dosimetry

International Nuclear Information System (INIS)

Ninkovic, M.; Bjelanovic, J.; Minincic, Z.; Komatina, R.; Raicevic, J.

1985-01-01

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. It was found that the maximum individual dose from external irradiation amounted to 8.2 mSV during past 10 months. Individual exposures for 7/10 of the personnel were less than 1/10 of the annual permissible exposure. Data are compared to radiation doses for last year and previous five years. Third part of this annex contains basic data about the quantity of collected radioactive waste, total quantity of contaminated and decontaminated surfaces. The last part analyzes accidents occurred at the reactor during 1985. It was found that there have been no accidents that could cause significant contamination of working surfaces and components nor radiation exposure of the personnel [sr

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)

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.

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.

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)

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)

Safety report for the independent CO2 loop for cooling the samples irradiated in the vertical experimental channels of the RA reactor

International Nuclear Information System (INIS)

Pavlovic, A.; Zivkovic, S.; Milosevic, M.; Strugar, P.

1969-01-01

Independent CO 2 loop was designed for cooling the samples irradiated in the vertical experimental channels in the region of heavy water or in the graphite reflector. It is considered as a significant improvement of the RA reactor experimental possibilities. Six 'heads' are placed in vertical experimental channels and connected in parallel with the outer loop which contains out-of-reactor equipment. It is planned to irradiate samples in the 'heads' of the loop for the needs of Hot laboratory and Laboratory for reactor materials. Heat generated during sample irradiation is removed by CO 2 circulation. This report contains detailed description of the main loop, auxiliary systems, calculation results of anti reactivity and activation of construction materials of the low-temperature CO 2 loop. A separate chapter is devoted to control and regulation of temperature and pressure. Testing of the fundamental parameters of the coolant loop showed that it could fulfill more demanding tasks than designed by the project. Annex of this report includes results of leak testing for the loop 'heads' in vertical experimental channels VEK-6 and VEK-8 by helium leak detector [sr

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

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.

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)

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).

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

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.

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.

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

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)

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

Analysis of RA-8 critical facility core in some configurations; Analisis del nucleo de la facilidad critica RA-8 en distintas configuraciones

Energy Technology Data Exchange (ETDEWEB)

Abbate, Maximo J [Instituto de Investigaciones Cientificas y Tecnicas de las Fuerzas Armadas (CITEFA), Villa Martelli (Argentina); Sbaffoni, Maria M [Comision Nacional de Energia Atomica, Buenos Aires (Argentina). Gerencia de Tecnologia

2000-07-01

The RA-8 critical facility was designated and built to be used in the experimental plan of the 'CAREM' Project but is, in itself, very versatile and adequate to perform many types of other experiments. The present paper includes calculated estimates of some critical configurations and comparisons with experimental results obtained during its start up. Results for Core 1 with homogeneous arrangement of rods containing 1.8 % enriched uranium, showed very good agreement. In fact, an experimentally critical configuration was reached with 1.300 rods and calculated values were: 1.310 using the WIMS code and 1.148 from the CONDOR code. Moreover, it was verified that the estimated number of 3.4% enriched uranium rods to be fabricated is enough to build a heterogeneous core or even a homogeneous core with this enrichment. The replacement of 3.4 % enriched uranium by 3.6 % will not present problems related with the original plan. (author)

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

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

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.

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)

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

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

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.

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)

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.

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

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

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.

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)

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).

Interleukin (IL)-8 and IL-36γ but not IL-36Ra are related to acrosyringia in pustule formation associated with palmoplantar pustulosis.

Science.gov (United States)

Xiaoling, Y; Chao, W; Wenming, W; Feng, L; Hongzhong, J

2018-06-12

Palmoplantar pustulosis (PPP) is a refractory, nonbacterial impetigo confined to the palms and soles. Its pathogenesis is still obscure, but it may be associated with the large eccrine sweat glands and pores of palmoplantar skin. PPP is considered to be a localized pustular psoriasis. Interleukin (IL)-8, IL-36γ and IL-36Ra play important roles in the pathogenesis of pustular psoriasis, but their role in PPP is unclear. To evaluate IL-8, IL-36γ and IL-36Ra expression in PPP, and their relationship with acrosyringia and pustule formation. mRNA expression was quantified in skin samples from patients with PPP (n = 7), patients with psoriasis vulgaris (PSV; n = 8) and healthy controls (HCs) (n = 6) by reverse-transcription-real-time PCR. Protein expression was characterized by immunohistochemistry (PPP, n = 17; PSV, n = 14; HCs, n = 12). Sweat ducts, including acrosyringia, were stained for epithelial membrane antigen (EMA). IL-8 mRNA and protein were markedly increased in PPP lesions compared with PSV lesions or HC skin. IL-36γ mRNA and protein were significantly more abundant in PPP lesions than in HC skin. IL-36Ra mRNA was significantly overexpressed in PPP lesions compared with HC skin, but there was no difference in IL-36Ra protein between PPP, PSV and HCs. IL-8 was abundantly expressed by neutrophils in PPP pustules, while IL36Ra was localized in the keratinocytes of PPP, PSV and HC skin. IL-36γ and EMA were colocalized in cells surrounding PPP pustules, and IL-36γ was also expressed in sweat duct cells in the dermis. IL-8, IL-36γ and IL-36Ra are overexpressed in PPP lesions. IL-8, IL-36γ and acrosyringia, rather than IL-36Ra, are associated with pustule formation in PPP. © 2018 British Association of Dermatologists.

Reactor Power Meter type SG-8

Energy Technology Data Exchange (ETDEWEB)

Glowacki, S W

1981-01-01

The report describes the principle and electronic circuits of the Reactor Power Meter type SG-8. The gamma radiation caused by the activity of the reactor first cooling circuit affectes the ionization chamber being the detector of the instrument. The output detector signal direct current is converted into the frequency of electric pulses by means of the current-to-frequency converter. The output converter frequency is measured by the digital frequency meter: the number of measured digits in time unit is proportional to the reactor power.

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)

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

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.

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)

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.

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

Analysis of RA-8 critical facility core in some configurations

International Nuclear Information System (INIS)

Abbate, Maximo J.; Sbaffoni, Maria M.

2000-01-01

The RA-8 critical facility was designated and built to be used in the experimental plan of the 'CAREM' Project but is, in itself, very versatile and adequate to perform many types of other experiments. The present paper includes calculated estimates of some critical configurations and comparisons with experimental results obtained during its start up. Results for Core 1 with homogeneous arrangement of rods containing 1.8 % enriched uranium, showed very good agreement. In fact, an experimentally critical configuration was reached with 1.300 rods and calculated values were: 1.310 using the WIMS code and 1.148 from the CONDOR code. Moreover, it was verified that the estimated number of 3.4% enriched uranium rods to be fabricated is enough to build a heterogeneous core or even a homogeneous core with this enrichment. The replacement of 3.4 % enriched uranium by 3.6 % will not present problems related with the original plan. (author)

Determination of the neutron spectrum at different locations in the Argentine RA-1 Reactor

International Nuclear Information System (INIS)

Lerner, A.M.; Madariaga, M.R.

1998-01-01

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 2 sec.eV) as a function of energy is also shown at the fast irradiation location. Values of flux (in n/cm 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 2 .sec). ((1) According to the reaction Au 197 (n,γ)Au 198 , having a cross section of σ 0 =98.8b for thermal neutrons. (2) According to the reaction In 115 (n,n')In 115m , with a cross section of some 70 mb for neutrons with energies above 1.2MeV). (author) [es

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)

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

Safety report for the independent CO{sub 2} loop for cooling the samples irradiated in the vertical experimental channels of the RA reactor; Izvestaj o sigurnosti za nezavisno kolo CO{sub 2} za hladjenje uzoraka ozracenih u vertikalnim eksperimentalnim kanalima reaktora RA

Energy Technology Data Exchange (ETDEWEB)

Pavlovic, A; Zivkovic, S; Milosevic, M; Strugar, P [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

1969-07-01

Independent CO{sub 2} loop was designed for cooling the samples irradiated in the vertical experimental channels in the region of heavy water or in the graphite reflector. It is considered as a significant improvement of the RA reactor experimental possibilities. Six 'heads' are placed in vertical experimental channels and connected in parallel with the outer loop which contains out-of-reactor equipment. It is planned to irradiate samples in the 'heads' of the loop for the needs of Hot laboratory and Laboratory for reactor materials. Heat generated during sample irradiation is removed by CO{sub 2} circulation. This report contains detailed description of the main loop, auxiliary systems, calculation results of anti reactivity and activation of construction materials of the low-temperature CO{sub 2} loop. A separate chapter is devoted to control and regulation of temperature and pressure. Testing of the fundamental parameters of the coolant loop showed that it could fulfill more demanding tasks than designed by the project. Annex of this report includes results of leak testing for the loop 'heads' in vertical experimental channels VEK-6 and VEK-8 by helium leak detector. [Serbo-Croat] Nezavisno kolo CO{sub 2} namenjeno je za hladjenje uzoraka ozracivanih u VEK reaktora u zoni teske vode i u zoni grafita, i predstavlja znacajan doprinos povecanju eksperimentalnih mogucnosti reaktora RA. Sest 'glava' je postavljeno u vertikalne eksperimentalne kanale i paralelno vezano na spoljno kolo koje sadrzi vanreaktorsku opremu. U glavama petlje se predvidja ozracivanje raznovrsnih uzoraka materijala za potrebe Laboratorije za visoku aktivnost i Laboratorije za reaktorske materijale. Toplota koja se generise prilikom ozracivanja uzoraka odvodi se cirkulacijom CO{sub 2}. Ovaj izvestaj sadrzi detaljan opis: glavnog kola, pomocnih sistema; rezultate proracuna antireaktivnosti i aktivacije konstrukcionih elemenata glave niskotemperaturne petlje CO{sub 2}. Posebno poglavlje posveceno

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)

Radiation protection at the RA Reactor in 1985, Part -2, Annex 1, Radioactivity control of working environment, dosimetry; Deo 2 - Zastita od zracenja kod reaktora RA u 1985. godini - Prilog 1 - Kontrola radne sredine - poslovi dozimetrije i tehnicke zastite od zracenja kod reaktora RA

Energy Technology Data Exchange (ETDEWEB)

Ninkovic, M; Bjelanovic, J; Minincic, Z; Komatina, R; Raicevic, J [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

1985-12-01

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. It was found that the maximum individual dose from external irradiation amounted to 8.2 mSV during past 10 months. Individual exposures for 7/10 of the personnel were less than 1/10 of the annual permissible exposure. Data are compared to radiation doses for last year and previous five years. Third part of this annex contains basic data about the quantity of collected radioactive waste, total quantity of contaminated and decontaminated surfaces. The last part analyzes accidents occurred at the reactor during 1985. It was found 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 radiacionih 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. Utvrdjeno je da je maksimalna individualna doza spoljasnjeg izlaganja u proteklih 10 meseci bila 8.2 mSv, a da su pojedinacna izlaganja vise od 7/10 radnog osoblja bila manja od 1/10 godisnje granicne vrednosti. Dati su takodje uporedni podaci o

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

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

Measuring the radium quartet (228Ra, 226Ra, 224Ra, 223Ra) in seawater samples using gamma spectrometry

International Nuclear Information System (INIS)

Beek, P. van; Souhaut, M.; Reyss, J.-L.

2010-01-01

Radium isotopes are widely used in marine studies (eg. to trace water masses, to quantify mixing processes or to study submarine groundwater discharge). While 228 Ra and 226 Ra are usually measured using gamma spectrometry, short-lived Ra isotopes ( 224 Ra and 223 Ra) are usually measured using a Radium Delayed Coincidence Counter (RaDeCC). Here we show that the four radium isotopes can be analyzed using gamma spectrometry. We report 226 Ra, 228 Ra, 224 Ra, 223 Ra activities measured using low-background gamma spectrometry in standard samples, in water samples collected in the vicinity of our laboratory (La Palme and Vaccares lagoons, France) but also in seawater samples collected in the plume of the Amazon river, off French Guyana (AMANDES project). The 223 Ra and 224 Ra activities determined in these samples using gamma spectrometry were compared to the activities determined using RaDeCC. Activities determined using the two techniques are in good agreement. Uncertainties associated with the 224 Ra activities are similar for the two techniques. RaDeCC is more sensitive for the detection of low 223 Ra activities. Gamma spectrometry thus constitutes an alternate method for the determination of short-lived Ra isotopes.

Fine structures in 14C emission of 223Ra and 224Ra

International Nuclear Information System (INIS)

Hourani, E.; Rosier, L.; Berrier-Ronsin, G.; Elayi, A.; Mueller, A.C.; Rappenecker, G.; Rotbard, G.; Renou, G.; Liebe, A.; Stab, L.

1991-01-01

The measurement of the energy spectrum of 14 C nuclei emitted in the spontaneous radioactivity from 223 Ra and 224 Ra has been carried out, using thin and intense sources (480 MBq for 223 Ra and 3550 MBq for 224 Ra). The sources were obtained by implanting mass-separated beams from ISOLDE (CERN) into Al and vitreous C catchers. The measurement was performed with the supraconducting solenoidal spectrometer SOLENO installed at Orsay. The discovery, of a fine structure in the energy spectrum of 14 C emission from 223 Ra, which is analogous to the one known for α emission, is confirmed. Only 13% of the branching ratio in 14 C decay leads to the ground state of the residual nucleus, while 8l% to the first excited state. For 14 C emission of 224 Ra, a lower limit of 2 for the hindrance factor has been measured for the transition to the first excited state in the residual nucleus. Also, a precise identification in Z with a E·ΔE telescope has been performed for the radiation from the 223 Ra source. (author) 22 refs., 11 figs., 1 tab

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

Cooling flow measurement in fuel elements of the RA-6

International Nuclear Information System (INIS)

Brollo, F; Silin, N

2009-01-01

Under the UBERA6 project for the core change and power increase of the RA-6 reactor, the total coolant flow was increased to meet the requirements imposed by the new operating conditions. The flow through the fuel elements is an important parameter and is difficult to determine due to the geometric complexity of the core. To ensure safe operation of the reactor, adequate safety margins must be kept for all operating conditions. In the present work we performed the direct measurement of the cooling flow rate of a fuel in the reactor core, for which we used a turbine flowmeter built specifically for this use. This helped to confirm previous results obtained during the launch, made by an indirect method based on measuring the pressure difference of the core. The turbine flowmeter was chosen due to its robustness, ease of operation and low disturbance of the input stream to the fuel. We describe the calibration of this instrument and the results of flow measurements made on some of the RA6 reactor fuel elements under conditions of zero power. [es

Design of fuel element for RA10

International Nuclear Information System (INIS)

Estevez, Esteban A.; Markiewicz, Mario; Gerding, Roberto

2012-01-01

The RA-10 reactor is an open pool multipurpose reactor. It is intended for radioisotopes production, fuel irradiation and use of neutron beam experiments. The nominal configuration core consists of 19 fuel elements (FE) and 6 in-core irradiation positions. With regard to the FE, although both conceptual design and manufacturing technology are similar to the already developed and qualified by CNEA (MTR fuel flat plate), the conditions imposed by the new reactor on FE's are more demanding that previous supplies. Here it should be mentioned the magnitude of the hydrodynamic forces acting on the FE caused by coolant flow through the core (upward) and mainly by the high coolant velocity between fuel plates (greater than 5 times than those currently in operation). Moreover, the high power density results in higher heat flux in fuel plates and greater temperature gradient. As a result of these increased demands present during irradiation, and in order to maintain a high level of reliability, it is necessary carry out some modifications in the mechanical design of the FE (with respect to the so-called ECBE design or s tandard ) . Design verification is performed through analytical and code calculations, and hydrodynamic tests on a full-scale prototype. This article describes the design of the FE for RA 10 reactor, with special emphasis on those aspects that represent innovations in the traditional design (ECBE). It also presents the functional requirements, design criteria and design limits established according to the reactor operational states (author)

Techniques for precise mapping of 226Ra and 228Ra in the ocean

International Nuclear Information System (INIS)

Moore, W.S.; Key, R.M.; Sarmiento, J.L.

1985-01-01

Improvements in the analyses of 226 Ra and 228 Ra in seawater made possible by better extraction and processing techniques reduce significantly the errors associated with these measurements. These improvements and the extensive sampling for Ra isotopes conducted on the TTO North Atlantic Study should enable us to use the distribution of 228 Ra to study mixing processes on a 3-15 year time scale in both the upper and deep North Atlantic. The 228 Ra profiles already analyzed show a closer resemblance to GEOSECS tritium data than to TTO tritium data in the upper ocean. This is because the transient tracer tritium was responding on a 10-year time scale during GEOSECS and a 20-year time scale during TTO. The steady state tracer 228 Ra should always respond on a time scale of 8 years. Thus the 228 Ra data obtained on TTO should provide a means to extend the features of the GEOSECS tritium field to the regions of the TTO study. The 226 Ra data are of high enough quality to identify features associated with different water masses. Changes in the positions of the deep-water masses since the GEOSECS cruise are revealed by the 226 Radata

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

Operators retraining in RA-1

International Nuclear Information System (INIS)

Pereira, R; Daoud, A

2012-01-01

The nuclear activity in Argentina has its foundational milestone in the creation of the Comision Nacional de EnergIa Atomica in 1950. Achievements since then, linked to the area of nuclear reactors and nuclear fuel materials, fuel cycle facilities and the applications of nuclear technology in medicine, industry, agriculture, food preservation, environmental studies and many others, have relied on personnel trained in this specific technology in both professional and technical level. This training has been done in most cases in the exclusive scope of CNEA. Eventually CNEA has been linked with the University to ensure that personnel training concerned to work done in the nuclear field had guarantees of formality and excellence. The creation of the Instituto de Tecnologia Nuclear Dan Beninson that, under an agreement with the Universidad Nacional de General San Martin, has set up an enabling environment for the training of professionals and university technicians to serve with the multiple and growing use of this technology. On the other hand the Institute has been issuing, along with its careers, specialized courses that, in some cases, have been requested by CNEA's nuclear installations and companies related to the nuclear sector. In particular, the Specialization in Nuclear Reactors and its Fuel Cycle (ERCC) and the Courses of Introduction to Nuclear Technology-Complementary training for Installations Personnel Class I (CI-CC), this last, recognized by the ARN as a requirement for applying to the individual licensing examination, providing work experience in the RA-1 reactor among which we can find commissioning, control rods calibration by various methods and calculations of reactivity. With this practical framework developed in the RA-1 and the academic support provided by the Instituto de Tecnologia Nuclear Dan Beninson it was developed a training program for nuclear reactors operators. Let us stress that this research reactor has been forming generations

Determination of 226Ra and 228Ra in surface seawater around Sagami bay and its vicinity

International Nuclear Information System (INIS)

Nakano-Ohta, T.; Kubota, T.; Mahara, Y.; Yoshikawa, M.; Sato, J.

2006-01-01

Activity ratios of 228 Ra/ 226 Ra in surface seawaters were observed at 5 ports of Izu-Oshima, Ajiro port of Sagami bay and Umizuri park of Tokyo bay. The 228 Ra/ 226 Ra activity ratio in surface seawaters were from 0.2 to 0.7 for Izu-Oshima, from 0.2 to 0.7 for Ajiro port and from 0.6 to 0.8 for Tokyo bay. The activity ratio in surface seawaters of Izu-Oshima and Atami of Sagami bay showed lower in spring and highly in autumn, while narrow variation pattern was observed in Umizuri park of Tokyo bay. The observed variation patterns of 228 Ra/ 226 Ra in surface seawaters at Izu-oshima, Ajiro park and Umizuri park may be reflected by difference of contribution from amount of seawater far off coast with low 228 Ra concentration. (author)

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

The decay scheme of 229Ra

International Nuclear Information System (INIS)

Yang, W.F.; Yuan, S.G.; Fang, K.M.; Shen, S.F.; Mou, W.T.; Zhang, X.Q.; Li, Z.Q.

1997-01-01

By bombarding the natural thorium targets with 14 MeV neutrons, 229 Ra was produced through the reaction 232 Th(n,α) 229 Ra. The radium activities were separated from the irradiated targets by coprecipitation with the BaCl 2 . A total of 18 new weak γ rays with energies of 14.5, 15.6, 18.8, 21.8, 22.5, 44.0, 47.5, 55.0, 63.0, 69.6, 93.6, 94.1, 98.5, 102.2, 104.5, 106.1, 161.1, and 171.5 keV which could be assigned to the decay of 229 Ra were observed in the isolated radium fractions employing high resolution HPGe detectors and γ(X)-γ coincidence methods. A decay scheme of 229 Ra based on these observations is proposed. (orig.). With 2 figs

Reactor oscillator - I - III, Part I; Reaktorski oscilator - I-III, I Deo

Energy Technology Data Exchange (ETDEWEB)

Lolic, B [Institute of Nuclear Sciences Boris Kidric, Laboratorija za fiziku reaktora, Vinca, Beograd (Serbia and Montenegro)

1961-12-15

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.

Annex 7 - Task 08/32 final report, Diffusion bond between the fuel and cladding of the RA reactor fuel element; Prilog 7 - Zavrsni izvestaj o podzadatku 08/32, Difuziona veza goriva i kosuljice gorivnog elementa reaktora RA

Energy Technology Data Exchange (ETDEWEB)

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

1961-12-15

Based on testing the diffusin bond between the fuel and the aluminium cladding of the RA reactor fuel element it was found that the diffusion bond exists; uranium is protected by a nickel layer to prevent the damaging diffusion between uranium and aluminium; the nickel layer is about 5 microns thick. Under assumption that the diffusion annealing was done after cladding the annealing temperature was about 500 deg C for about 1 hour.

Status report about the works for the start up of the RA-0 'zero power' nuclear reactor at the Cordoba National University

International Nuclear Information System (INIS)

Martin, H.R; Carballido, C.; Oliveras, T.

1991-01-01

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) [es

Assessment of "2"2"6Ra, "2"2"8Ra and "2"1"0Pb concentration in mineral waters from Parque das Águas de Lambari and Contendas, MG and evaluation of the committed effective doses

International Nuclear Information System (INIS)

Wakasugi, Denise S.M.; Damatto, Sandra R.

2017-01-01

The exploration of several Brazilian hydromineral resorts, that have springs of radioactive mineral water consumed by the population support the relevance of the present work. This study is being developed in the IPEN with the aid of the responsible for Parque das Águas de Lambari and Contendas. Thereby, this work aims to determine the activity concentrations of "2"2"6Ra, "2"2"8Ra and "2"1"0Pb to verify the influence of seasonality in these water parks springs. Thereunto, gross alpha and beta measurements were used after radiochemical separation for these radionuclides determination and measurement in a low background proportional detector. The results showed that Parque das Águas de Lambari presented highest concentration values when compared with Contendas. In Parque das Águas de Contendas , the highest concentration values were 77 ± 5 mBq/L and 129 ± 5 mBq/L for "2"2"6Ra for Gasosa II springs and "2"2"8Ra for Gasosa I spring, respectively, which correspond to the spring season; for "2"1"0Pb, 27 ± 2 mBq/L for Magnesiana spring in the same season. In Parque das Águas de Lambari, the highest concentration values for "2"2"6Ra was 177 ± 2 mBq/L and for "2"1"0Pb, 36 ± 2 mBq/L, both in the Magnesiana spring, for the summer season and 135 ± 5 mBq/L for "2"2"8Ra, in Magnesiana spring, for the spring season. The data were analyzed through descriptive and correlational statistical techniques. Therefore, it was possible to evaluate the committed effective doses due to the consumption of these waters and to assess the radiological risk for the radionuclides studied. (author)

Report of the reactor Operators Service - Annex F

International Nuclear Information System (INIS)

Zivotic, Z.

1992-01-01

RA reactor operators service is organized in two groups: permanent staff (chief operator, chief shift operators and operators) and changeable group which is formed according to the particular operation needs for working in shifts. For continuous training of the existing operator staff the Service has prepared and published eleven booklets: Nuclear reactor; RA reactor primary coolant loop; System for purification of heavy water; reactor helium system; system for technical water; electric power system; control and operation; ventilation system in the reactor building; special sewage system; construction properties of the reactor core; reactor building and installations. During the reporting period there have been no accidents nor incidents that could affect the reactor personnel [sr

Operation and maintenance of the RA reactor, Report on operation in 1967, task 7.08; Pogon i odrzavanje reaktora RA, Izvestaj o radu u 1967. god. Zadtak 7.08

Energy Technology Data Exchange (ETDEWEB)

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

1967-12-15

During 1967, RA reactor was operated at nominal power for 190 days and 23 days at lower power levels. The total production was 31060 MWh. Report contains data until Dec. 22. 1967, but the reactor was planned to operate three more full days at nominal power of 6.5 MW, meaning that the total number of operation at full power would be 193 days ant the total production would be 30625 which is 2% higher than planned. Practically there were no discrepancies from the plan. There have been 5 shorter interruptions in operation caused by demand of the experiment, minor repairs and thunderstorm. Only one longer interruption was caused by difficulties in secondary water supply. The reactor was used for irradiation and experiments according to the demand of 590 users, of which 470 were from the Institute. This report contains detailed data about reactor power and experiments performed in 1967, 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 19, of which 11 were caused by power cuts, 6 due to voltage instabilities, and 2 due to failures of instrumentation. These data are compared to safety shutdown data from 1962 - 1967. There have been no accidents which could cause any significant effects. The only important incident occurred this year was caused by leaking of sulphur from an experimental capsule. It is described in detail. Detailed data concerning exposure of the personnel are part of this report. In spite of the fact that this year the spent fuel was for the first time packed and mixing of the fuel in the core there have been no unplanned difficulties nor contaminations.

Radiation protection at the RA Reactor in 1995, Part -2, Annex 2, 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.

1995-01-01

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

Radiation protection at the RA Reactor in 1998, Part 2, Annex 2, Decontamination and actions, collection of liquid effluents and solid radioactive waste

International Nuclear Information System (INIS)

Mandic, M.; Vukovic, Z.; Bacic, S.; Plecas, I.

1998-01-01

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

New experimental space for irradiating samples by RA reactor fast neutron flux at temperatures up to 100 deg C; Novi eksperimentalni prostori namenjeni ozracivanju uzoraka u fluksu brzih neutrona na temperaturama do 100{sup 0} C na reaktoru RA

Energy Technology Data Exchange (ETDEWEB)

Pavicevic, M; Novakovic, M; Zecevic, V [Boris Kidric Institute of nuclear sciences, Vinca, Belgrade (Yugoslavia)

1961-07-01

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.

Automated measurement of 224Ra and 226Ra in water

International Nuclear Information System (INIS)

Dimova, N.; Burnett, W.C.; Horwitz, E.P.; Lane-Smith, D.

2007-01-01

We present a new simple approach for automated, non-destructive measurement of the alpha-emitting radium isotopes ( 223 Ra, 224 Ra, and 226 Ra) in water based on the emanation of their respective radon daughters ( 219 Rn, 220 Rn, and 222 Rn). The method combines the high adsorption uptake of MnO 2 Resin for radium (K d =2.4x10 4 ml/g) over a wide pH range with the simplicity of the activity registration using a commercial radon-in-air analyzer (RAD7, DURRIDGE Company, Inc). Radium is first adsorbed onto the MnO 2 Resin by passing a water sample through the resin packed in a gas-tight glass cartridge. The same cartridge is then connected to the radon analyzer via a simple tubing system to circulate air through the resin and a drying system. The efficiency of the proposed system is determined by running standards prepared in the same manner. Our results indicate that the efficiency for 226 Ra is >22% if both 218 Po and 214 Po counts are collected. This is comparable with typical efficiencies for alpha spectrometry but with much less sample preparation. We estimate that an MDA of 0.8 pCi/L for 226 Ra may be obtained with this new approach using a 1 L water sample and less than 4 h of counting

Measuring the radium quartet ({sup 228}Ra, {sup 226}Ra, {sup 224}Ra, {sup 223}Ra) in seawater samples using gamma spectrometry

Energy Technology Data Exchange (ETDEWEB)

Beek, P. van, E-mail: vanbeek@legos.obs-mip.f [LEGOS, Laboratoire d' Etudes en Geophysique et Oceanographie Spatiales (CNRS/CNES/IRD/UPS), Observatoire Midi Pyrenees, 14 Avenue Edouard Belin, 31400 Toulouse (France); Souhaut, M. [LEGOS, Laboratoire d' Etudes en Geophysique et Oceanographie Spatiales (CNRS/CNES/IRD/UPS), Observatoire Midi Pyrenees, 14 Avenue Edouard Belin, 31400 Toulouse (France); Reyss, J.-L. [LSCE, Laboratoire des Sciences du Climat et de l' Environnement (CNRS/CEA/UVSQ), Avenue de la Terrasse, 91198 Gif-sur-Yvette (France)

2010-07-15

Radium isotopes are widely used in marine studies (eg. to trace water masses, to quantify mixing processes or to study submarine groundwater discharge). While {sup 228}Ra and {sup 226}Ra are usually measured using gamma spectrometry, short-lived Ra isotopes ({sup 224}Ra and {sup 223}Ra) are usually measured using a Radium Delayed Coincidence Counter (RaDeCC). Here we show that the four radium isotopes can be analyzed using gamma spectrometry. We report {sup 226}Ra, {sup 228}Ra, {sup 224}Ra, {sup 223}Ra activities measured using low-background gamma spectrometry in standard samples, in water samples collected in the vicinity of our laboratory (La Palme and Vaccares lagoons, France) but also in seawater samples collected in the plume of the Amazon river, off French Guyana (AMANDES project). The {sup 223}Ra and {sup 224}Ra activities determined in these samples using gamma spectrometry were compared to the activities determined using RaDeCC. Activities determined using the two techniques are in good agreement. Uncertainties associated with the {sup 224}Ra activities are similar for the two techniques. RaDeCC is more sensitive for the detection of low {sup 223}Ra activities. Gamma spectrometry thus constitutes an alternate method for the determination of short-lived Ra isotopes.

Document control system as an integral part of RA documentation database application

International Nuclear Information System (INIS)

Steljic, M.M; Ljubenov, V.Lj. . E-mail address of corresponding author: milijanas@vin.bg.ac.yu; Steljic, M.M.)

2005-01-01

The decision about the final shutdown of the RA research reactor in Vinca Institute has been brought in 2002, and therefore the preparations for its decommissioning have begun. All activities are supervised by the International Atomic Energy Agency (IAEA), which also provides technical and experts' support. This paper describes the document control system is an integral part of the existing RA documentation database. (author)

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)

Radiation protection at the RA Reactor in 1997, Part -2, Annex 1, Control of the working environment, dosimetry and radiation protection; Prilog 1 - Zastita od zracenja kod reaktora RA u 1997. godini - Deo 2 - Kontrola radne sredine - dozimetrija i tehnicka zastita kod reaktora RA

Energy Technology Data Exchange (ETDEWEB)

Pavlovic, R; Kalinic, S [Vinca Institute of Nuclear Sciences, Beograd (Serbia and Montenegro)

1997-12-01

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 1997. Actions in 1997 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. After adopting the procedures, detailed preparations, and purchasing the needed equipment, the first phase of remedial action, the removal of the sludge from the bottom of the spent fuel storage pool was started in September 1997. 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 radiacionih 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

Radium isotope (223Ra, 224Ra, 226Ra and 228Ra) distribution near Brazil's largest port, Paranaguá Bay, Brazil

International Nuclear Information System (INIS)

Dias, Thais H.; Oliveira, Joselene de; Sanders, Christian J.; Carvalho, Franciane; Sanders, Luciana M.; Machado, Eunice C.; Sá, Fabian

2016-01-01

This work investigates the 223 Ra, 224 Ra, 226 Ra and 228 Ra isotope distribution in river, estuarine waters and sediments of the Paranaguá Estuarine Complex (PEC). The stratification of the Ra isotopes along water columns indicate differing natural sources. In sediments, the radium isotope activities was inversely proportional to the particle size. The highest concentrations of 223 Ra, 224 Ra, 226 Ra and 228 Ra in the water column were found in the bottom more saline waters and towards the inner of the estuary. These relatively high concentrations towards the bottom of the estuary may be attributed to the influence of tidally driven groundwater source and desorption from particles at the maximum turbidity zone. The apparent river water ages from the radium isotope ratios, 223 Ra/ 224 Ra and 223 Ra/ 228 Ra, indicate that the principal rivers that flow into the estuary have residence times from between 6 and 11 days. - Highlights: • Radium isotope concentrations were evaluated along a large estuarine system. • The radioactivity level in river, estuary and sediments was within a normal range. • Spatial distributions of site specific radionuclides have differing activities and sources.

226Ra measurement by thermal ionisation mass spectrometry: Use of 226Ra and 14C for groundwater dating

International Nuclear Information System (INIS)

Dever, L.

1997-01-01

Recent developments in thermal ionisation mass spectrometry (TIMS) and in chemical separation Ra and Ba allow to analyse 226 Ra on smaller water samples ( 3 litres). The sampling has been realised on the Chalk aquifer of the Paris basin. The water samples have been collected in the unsaturated zone using in situ filtering devices and in the unconfined and confined parts of the aquifer in the boreholes used for public water supply. 226 Ra contents vary from 0.064±0.02 dpm/kg (n=6) in the unsaturated zone to 0.119±0.069 dpm/kg (n=7) in the unconfined aquifer and 0.319±0.057 dpm/kg (n=9) in the confined aquifer. For all the samples the 226 Ra/ 238 U activity ratios are much lower than the secular equilibrium. This points out that the two isotopes have different input function in the water during the mineralisation of the solution. The good correlation (r 2 =0.9) between the 226 Ra and Sr indicates that dissolution of Chalk is the dominant mechanism of mineralisation in 226 Ra of the solution. In the Chalk the mineralisation of the water occurs in the first metres of the unsaturated zone, during the water percolation the water rock interaction takes place through dissolution and precipitation of calcite in a non steady state. According to his distribution coefficient Sr is then a better tracer of dissolution/precipitation process than Ba. Using a geochemical model based on 226 Ra/Sr and Sr/Ca ratios an 'age' of the water could be determined. With 226 Ra half life of 1620 years we obtain 'ages' varying from 150 years to 1950 years in the unconfined aquifer. For the confined part of the aquifer where the redox condition is different it is necessary to use a geochemical model based on the U concentration in the water, the 226 Ra gives in such case ages varying from 1.8ka to 12.8ka. The radiocarbon ages obtained through usual chemical and/or isotopic models are quite similar and an isochrome between 226 Ra and 14 C ages can be calculated between 0 and 8ka

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

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)

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

Experimental researches of nuclear reactor neutron and gamma radiation scattering into the atmosphere

International Nuclear Information System (INIS)

Istomin, Yu.L.; Zelensky, D.I.; Cherepnin, Yu.S.; Orlov, Yu.V.; Netecha, M.E.; Avaev, V.N.; Vasel'ev, G.A.; Sakamoto, H.; Nomura, Y.; Naito, Y.

1998-01-01

In the report there are results of measuring radiation distribution on the caps of the RA and IWG.1M research reactors. Comparative analysis of the results is also in the report. There are neutron spectra in the interval of energies from 10 -9 to 13 MeV above RA and IWG.1M reactors. The spectra were measured with a set of activation detectors. Measurements were calculated to a nominal rate: for RA reactor - 300 kw, for IWG.1M - 7 MW. Thus, in the course of the experiment, vast experimental information relating to distribution of the RA and IWG.1M reactor gamma and neutron radiation scattered in the air for distances varying from 50 to 1000 m from the reactors has become available. The data obtained are to be used to verify the calculation codes and to validate the group nuclear constants

Does a family history of RA influence the clinical presentation and treatment response in RA?

Science.gov (United States)

Frisell, Thomas; Saevarsdottir, Saedis; Askling, Johan

2016-06-01

To assess whether family history of rheumatoid arthritis (RA), among the strongest risk factors for developing RA, also carries information on the clinical presentation and treatment response. The prospective Swedish Rheumatology register was linked to family history of RA, defined as diagnosed RA in any first-degree relative, ascertained through the Swedish Multi-Generation and Patient registers. Clinical presentation was examined among patients with early RA 2000-2011 (symptom onset clinical characteristics, drug survival, European League Against Rheumatism (EULAR) response and change in disease activity at 3 and 6 months was estimated using linear and generalised logistic regression models. Correlation in relatives' response measures was also assessed. Patients with early RA with family history of RA were more often rheumatoid factor positive, but with no other clinically meaningful differences in their clinical presentation. Family history of RA did not predict response to MTX or TNFi, with the possible exception of no versus good EULAR response to TNFi at 6 months (OR=1.4, 95% CI 1.1 to 1.7). Having a relative who discontinued TNFi within a year increased the odds of doing the same (OR=3.7, 95% CI 1.8 to 7.5), although we found no significant familial correlations in change in disease activity measures. Family history of RA did not modify the clinical presentation of RA or predict response to standard treatment with MTX or TNFi. Treatment response, particularly drug survival, may itself be familial. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Study on the technical feasibility of Fission-Track dating at two irradiation positions of the RA-6 research reactor

International Nuclear Information System (INIS)

Dorval, Eric

2005-01-01

The method of Fission-Track dating is based upon the detection of the damage caused by fission fragments from the Uranium contained in geological samples.In order to determine the age of a sample, both the amount of spontaneous fissions occurred and the Uranium concentration must be known.The latter requires the irradiation of the samples inside a reactor with a well-thermalized flux, so that fissions are induced over 235 U targets only. Therefore, the Uranium concentration may be determined.The main inconvenient presented by the irradiation sites at the RA-6 MTR-type reactor is that neutron flux is not completely thermal there, which means that fissions due to epithermal and fast neutrons will not be negligible.In the same way, tracks due to fissions of 238 U and 232 Th will be detected. In order to know the corrections that must be applied to those measurements performed in this reactor, it is necessary to characterize fast flux.Because of it, this laboratory's gamma spectrometry equipment had to be calibrated. After that, several activation detectors were irradiated and results were analyzed. Finally, it was determined that it is feasible to Fission-Track date at the I6 position. However, limitations associated to this method were analyzed for the values of flux measured in the different sites

Development of a liquid scintillation method for in vitro determination of 226Ra and 228 Ra in bioassay samples

International Nuclear Information System (INIS)

Fernandes, Paulo Cesar P.; Sousa, Wanderson O.; Juliao, Ligia M.Q.C.; Dantas, Bernardo M.

2011-01-01

Radium isotopes are dispersed in the environment according to their physicochemical characteristics. The intake of 226 Ra and 228 Ra in humans can occur by inhalation and ingestion and the risk of internal exposure are related to their long half-lives, characteristics of the emission and biokinetics of the isotopes in the human body. The goal of this work is to develop a methodology for the analysis of 226 Ra and 228 Ra in excreta samples (urine and feces), using liquid scintillation technique. Excreta samples were provided by non-exposed humans for the purpose of standardizing the methodology and the establishment of a background level of radium excretion. Radium isotopes were concentrated and separated from the constituents of the sample by co-precipitation with barium sulphate. The precipitate of Ba(Ra)SO 4 was filtrated and weighted for the determination of the chemical yield. The filter containing the precipitate was transferred to a scintillation vial. In the scintillation vial, 8 mL of water, 8 mL of Instagel XF and 4 mL of UltimaGold were added, forming a gel suspension, after stirring the solution. The 226 Ra and 228 Ra activities were determined 21 days after the precipitation of samples. The samples were counted in a liquid scintillation spectrometer. The technique presented adequate sensitivity and reproducibility for the analysis of urine and feces. The activities of 226 Ra and 228 Ra in excreta samples provide useful information for the identification of the main route of intake and for the assessment of the internal exposure of occupationally exposed workers and inhabitants of high background areas. (author)

Theoretical analysis of nuclear reactors (Phase III), I-V, Part III, Reactor poisoning; Razrada metoda teorijske analize nuklearnih reaktora (III faza) I-IV, III Deo, Zatrovanje reaktora

Energy Technology Data Exchange (ETDEWEB)

Pop-Jordanov, J [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

1963-01-15

Report on calculation of poisoning in experimental and power reactor includes four parts. Part one describes the influence of poisoning on the physical parameters of a reactor. part two includes transformation of differential equations for iodine and xenon. It was needed for easier solution of of differential equation using the analog computer. This calculation was done for RA reactor operating at 5 MW power. The RA reactor was used an example of calculation by the proposed method. Part four shows the application of the method for calculating the Calder Hall power reactor.

Fixing tools of targets for radioisotope production in the RA10

International Nuclear Information System (INIS)

Peirone, M.; Coleff, A.; Chasseur, A.

2012-01-01

The RA-10 project is about the design and construction of a reactor for radioisotopes production and scientific research in the nuclear area. Most of the reactor design comes from INVAP SE, however some of the design job was performed in CNEA, i.e. the so called Outer Core Experimental Devices (DEEN) and their interfaces with the Reflector Tank were designed in CNEA and the documentation of the basic design was recently released (author)

Determination of the convection coefficients of the new core of the RA6

International Nuclear Information System (INIS)

Silin, Nicolas; Masson, Viviana P.; Azcona, Maria A.; Delmastro, Dario F.; Mateos Bickel, Daniel E.; Eckardt, S.

2007-01-01

The experimental reactor RA-6 has a core with fuel elements formed by flat plates, refrigerated by a flow of water. The fluid movement in the core is downward, which is advantageous from the point of view that water is turned away from the pool mouth. For the study of the heat transfer in the fuel elements correlations developed for flat parallel plates are often used. Under the project for core replacement and power augmentation in the experimental reactor RA-6 there is a need to increase the cooling flow of the core. In the new conditions the hydrodynamic flow regime is transitional. This fact combined with the high heat flux and the downward flow of coolant make the design correlations must be verified. Therefore the objective of this work is to experimentally determine the coefficient of convection between the fuel plates in the reactor core in the range of 3000 2 and 150 C degrees wall temperature. (author) [es

Control of the working environment dosimetry and technical radiation protection at the RA reactor, Part I; Deo I: Kontrola radne sredine - poslovi dozimetrije i tehnicke zastite od zracenja kod reaktora RA

Energy Technology Data Exchange (ETDEWEB)

Ninkovic, N; Bjelanovic, J; Minicic, Z; Komatina, R; Raicevic, J [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

1984-12-15

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. It was found that the maximum individual dose from external irradiation amounted to 16.9 mSV during past 10 months. Individual exposures for 9/10 of the personnel were less than 1/10 of the permissible annual exposure. Data are compared to radiation doses for last year and previous five years. Third part of this annex contains basic data about the quantity of collected radioactive waste, total quantity of contaminated and decontaminated surfaces. The last part analyzes accidents occurred at the reactor during 1984. It was found that there have been no accidents that could cause significant contamination of working surfaces and components nor radiation exposure of the personnel.

Pulmonary cryptococcosis in rheumatoid arthritis (RA) patients: Comparison of imaging characteristics among RA, acquired immunodeficiency syndrome, and immunocompetent patients

International Nuclear Information System (INIS)

Yanagawa, Noriyo; Sakai, Fumikazu; Takemura, Tamiko; Ishikawa, Satoru; Takaki, Yasunobu; Hishima, Tsunekazu; Kamata, Noriko

2013-01-01

Purpose: The imaging characteristics of cryptococcosis in rheumatoid arthritis (RA) patients were analyzed by comparing them with those of acquired immunodeficiency syndrome (AIDS) and immunocompetent patients, and the imaging findings were correlated with pathological findings. Methods: Two radiologists retrospectively compared the computed tomographic (CT) findings of 35 episodes of pulmonary cryptococcosis in 31 patients with 3 kinds of underlying states (10 RA, 12 AIDS, 13 immunocompetent), focusing on the nature, number, and distribution of lesions. The pathological findings of 18 patients (8 RA, 2 AIDS, 8 immunocompetent) were analyzed by two pathologists, and then correlated with imaging findings. Results: The frequencies of consolidation and ground glass attenuation (GGA) were significantly higher, and the frequency of peripheral distribution was significantly lower in the RA group than in the immunocompetent group. Peripheral distribution was less common and generalized distribution was more frequent in the RA group than in the AIDS group. The pathological findings of the AIDS and immunocompetent groups reflected their immune status: There was lack of a granuloma reaction in the AIDS group, and a complete granuloma reaction in the immunocompetent group, while the findings of the RA group varied, including a complete granuloma reaction, a loose granuloma reaction and a hyper-immune reaction. Cases with the last two pathologic findings were symptomatic and showed generalized or central distribution on CT. Conclusion: Cryptococcosis in the RA group showed characteristic radiological and pathological findings compared with the other 2 groups

Pulmonary cryptococcosis in rheumatoid arthritis (RA) patients: Comparison of imaging characteristics among RA, acquired immunodeficiency syndrome, and immunocompetent patients

Energy Technology Data Exchange (ETDEWEB)

Yanagawa, Noriyo, E-mail: noriyo_yana@ybb.ne.jp [Departments of Radiology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, 3-8-22, Honkomagome, Bunkyo-ku, Tokyo 113-8677 (Japan); Sakai, Fumikazu [Department of Diagnostic Radiology, Saitama Medical University International Medical Center, 1397-1 Yamane, Hidaka-shi, Saitama 350-1298 (Japan); Takemura, Tamiko [Department of Pathology, Japanese Red Cross Medical Center, 4-1-22 Hiroo, Shibuya-ku, Tokyo 150-8935 (Japan); Ishikawa, Satoru [Department of Respiratory Medicine, National Hospital Organization Chiba-East-Hospital, 673 Nitona-cho, Chuo-ku, Chiba-shi, Chiba 260-8712 (Japan); Takaki, Yasunobu [Departments of Radiology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, 3-8-22, Honkomagome, Bunkyo-ku, Tokyo 113-8677 (Japan); Hishima, Tsunekazu [Department of Pathology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, 3-8-22, Honkomagome, Bunkyo-ku, Tokyo 113-8677 (Japan); Kamata, Noriko [Departments of Radiology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, 3-8-22, Honkomagome, Bunkyo-ku, Tokyo 113-8677 (Japan)

2013-11-01

Purpose: The imaging characteristics of cryptococcosis in rheumatoid arthritis (RA) patients were analyzed by comparing them with those of acquired immunodeficiency syndrome (AIDS) and immunocompetent patients, and the imaging findings were correlated with pathological findings. Methods: Two radiologists retrospectively compared the computed tomographic (CT) findings of 35 episodes of pulmonary cryptococcosis in 31 patients with 3 kinds of underlying states (10 RA, 12 AIDS, 13 immunocompetent), focusing on the nature, number, and distribution of lesions. The pathological findings of 18 patients (8 RA, 2 AIDS, 8 immunocompetent) were analyzed by two pathologists, and then correlated with imaging findings. Results: The frequencies of consolidation and ground glass attenuation (GGA) were significantly higher, and the frequency of peripheral distribution was significantly lower in the RA group than in the immunocompetent group. Peripheral distribution was less common and generalized distribution was more frequent in the RA group than in the AIDS group. The pathological findings of the AIDS and immunocompetent groups reflected their immune status: There was lack of a granuloma reaction in the AIDS group, and a complete granuloma reaction in the immunocompetent group, while the findings of the RA group varied, including a complete granuloma reaction, a loose granuloma reaction and a hyper-immune reaction. Cases with the last two pathologic findings were symptomatic and showed generalized or central distribution on CT. Conclusion: Cryptococcosis in the RA group showed characteristic radiological and pathological findings compared with the other 2 groups.

226Ra, 228Ra, 223Ra, and 224Ra in coastal waters with application to coastal dynamics and groundwater input

International Nuclear Information System (INIS)

Moore, W.S.

1997-01-01

Four radium isotopes offer promise in unraveling the complex dynamics of coastal ocean circulation and groundwater input. Each isotope is produced by decay of a thorium parent bound to sediment. The activities of these thorium isotopes and the sediment-water distribution coefficient for radium provide an estimate of the source function of each Ra isotope to the water. In salt marshes that receive little surface water input, Ra activities which exceed coastal ocean values must originate within the marsh. In North Inlet, South Carolina, the activities of 226 Ra exported from the marsh far exceed the activities generated within the marsh. To supply the exported activities, substantial groundwater input is required. In the coastal region itself, 226 Ra activities exceed the amount that can be supplied from rivers. Here also, substantial groundwater input is required. Within the coastal ocean, 223 Ra and 224 Ra may be used to determine mixing rates with offshore waters. Shore-perpendicular profiles of 223 Ra and 224 Ra show consistent trends which may be modeled as eddy diffusion coefficients of 350-540 m 2 s -1 . These coefficients allow an assessment of cross-shelf transport and provide further insight on the importance of groundwater to coastal regions. (author)

RA radiological characterization database application

International Nuclear Information System (INIS)

Steljic, M.M; Ljubenov, V.Lj. . E-mail address of corresponding author: milijanas@vin.bg.ac.yu; Steljic, M.M.)

2005-01-01

Radiological characterization of the RA research reactor is one of the main activities in the first two years of the reactor decommissioning project. The raw characterization data from direct measurements or laboratory analyses (defined within the existing sampling and measurement programme) have to be interpreted, organized and summarized in order to prepare the final characterization survey report. This report should be made so that the radiological condition of the entire site is completely and accurately shown with the radiological condition of the components clearly depicted. This paper presents an electronic database application, designed as a serviceable and efficient tool for characterization data storage, review and analysis, as well as for the reports generation. Relational database model was designed and the application is made by using Microsoft Access 2002 (SP1), a 32-bit RDBMS for the desktop and client/server database applications that run under Windows XP. (author)

Characterization of the neutron flow for the implementation of an experimental analysis installation for rapid gamma activation in the Argentine Research Reactor RA-6

International Nuclear Information System (INIS)

Henriquez, C.; Gennuso, G.

2000-01-01

This is the final work to obtain a Diploma on Specialization in Application of Nuclear Technological Energy, carried out at the Research Reactor RA-6, from March to December 1999. Different work has been realized on the Tangential Tube N of the 500 KW Argentine RA-6 research reactor, in order to add a new technique to the present existing analytical methods. This Prompt Gamma Neutron Activation Analysis technique (PGNAA) requires a beam of collimated thermal neutrons, a lowest possible gamma radiation, and a thermal component of the biggest possible cadmium rate. It also must have a high resolution detection system for the measurement of the gamma radiation emitted after the capture of the neutron produced in the study sample. Continuing with the facility's technical requirements, a collimator was installed inside the N passing tube, in order to concentrate the neutrons coming from the nuclear core and also to compensate possible losses during the path. This collimator is 440mm long and 200 mm in diameter and consists of lead and steel cylinders with different size holes on the inside, so that it can deliver a 50 mm diameter beam of thermal collimated neutrons. Two 100 mm thick bismuth filters are inside the passing tube, to reduce the gamma component inside de beam, coming from the reactor core. This work aims to the characterization of the thermal and epithermal component of the neutron beam in the collimator and at the exit of it , and also to prove experimentally that the collimator achieves the technical specifications for which it was designed and built, specifically by verifying its functioning (degree of convergence of the beam obtained). On the other hand, it is necessary to learn about the PGNAA technique in order to define the technical requirements for its adequate operation. (author)

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.

Experimental study of the correction factor for the grid by-pass orifices inlet pressure drop for the new core of the RA 6 reactor

International Nuclear Information System (INIS)

Masson, Viviana P.; Garcia, Juan C.; Delmastro, Dario F.

2007-01-01

It is necessary to determine the pressure drop in the different components in order to calculate the total pressure drop of RA-6 reactor core. Some of these components have simple geometries and the calculation of its pressure drop is relatively easy. But in some cases, the sub-channels where the cooling water flows have non uniform cross sections and its geometries are not in the handbook. Due to changes in the design of components of the new nucleus of the RA-6 it was necessary to perform a new set of full-scale experiments to determine the pressure drop in some affected subchannels. Different gaps between fuel elements are considered in order to take into account the design allowances. With the obtained results we calculate correction coefficients for the pressure loss coefficients. These coefficients allow fitting the model of calculation with the results obtained in the experiments and they were used to calculate the flow distribution in the core. (author) [es

Measurement of gamma radiation doses at the RA reactor by thermoluminescent dosemeters