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Sample records for vyskumneho reaktoru vvr-s

  1. Management of Spent Nuclear Fuel of Nuclear Research Reactor VVR-S at the National Institute of Physics and Nuclear Engineering, Bucharest, Romania

    Science.gov (United States)

    Biro, Lucian

    2009-05-01

    The Nuclear Research Reactor VVR-S (RR-VVR-S) located in Magurele-Bucharest, Romania, was designed for research and radioisotope production. It was commissioned in 1957 and operated without any event or accident for forty years until shut down in 1997. In 2002, by government decree, it was permanently shutdown for decommissioning. The National Institute of Physics and Nuclear Engineering (IFIN-HH) is responsible for decommissioning the RR-VVR-S, the first nuclear decommissioning project in Romania. In this context, IFIN-HH prepared and obtained approval from the Romanian Nuclear Regulatory Body for the Decommissioning Plan. One of the most important aspects for decommissioning the RR-VVR-S is solving the issue of the fresh and spent nuclear fuel (SNF) stored on site in wet storage pools. In the framework of the Russian Research Reactor Fuel Return Program (RRRFR), managed by the U.S. Department of Energy and in cooperation with the International Atomic Energy Agency and the Rosatom State Corporation, Romania repatriated all fresh HEU fuel to the Russian Federation in 2003 and the HEU SNF will be repatriated to Russia in 2009. With the experience and lessons learned from this action and with the financial support of the Romanian Government it will be possible for Romania to also repatriate the LEU SNF to the Russian Federation before starting the dismantling and decontamination of the nuclear facility. [4pt] In collaboration with K. Allen, Idaho National Laboratory, USA; L. Biro, National Commission for Nuclear Activities Control, Romania; and M. Dragusin, National Institute of Physics and Nuclear Engineering, Bucharest-Magurele, Romania.

  2. Conditioning of pretreated LLW generated by the decontamination of VVR-S nuclear research reactor primary circuit

    Energy Technology Data Exchange (ETDEWEB)

    Nicu, Mihaela I.; Ionascu, Laura A.; Dragolici, Felicia N.; Turcanu, Corneliu N.; Rotarescu, Gheorghe Gh.; Dogaru, Gheorghe C. [' Horia Hulubei' National Institute for Nuclear Physics and Engineering Magurele, Ilfov (Romania)

    2013-07-01

    Concentration of complexing acids solutions (oxalic acid, tartaric acid and citric acid) used in radioactive decontamination by chemical method affects both the mechanical stability and the chemical stability of cement matrix. The paper presents the works performed related to the chemical pretreatment of these organic acids solutions using as neutralizing agent Ca(OH){sub 2}. In this way it was possible to increase the concentration of organic acids solutions used and the soluble complex radionuclides passing in chemical precipitates, these affecting in a smaller manner the mechanical stability of the cement matrix. The chemical pretreatment the effluents improve the precipitation and conditioning performances by cementation. Were prepared compositions with complexing agents and compositions for oxidative degradation tests to simulate the concentrations of secondary radioactive waste obtained from the primary circuit decontamination of the VVR-S research reactor. It has been studied the influence of chemical pretreatment of complexing acids solutions of different concentrations on the setting time. Also it was determined the compressive strength of mortar samples in which were embedded these solutions of chemically pretreated organic acids. The results shown that an optimum cement - solution ratio doesn't have a significant impact on the setting time or on the mechanical properties. (authors)

  3. Assessment of derived emission limits for radioactive effluents resulted from the decommissioning activities of the VVR-S nuclear research reactor.

    Science.gov (United States)

    Tuca, C; Stochioiu, A; Sahagia, M; Gurau, D; Dragusin, M

    2015-10-01

    This paper presents complex studies on establishment of derived emission limits for potential radionuclides emitted as gaseous and liquid effluents, during the decommissioning activities (2nd and 3rd phases) of a nuclear research reactor, cooled and moderated with distilled water, type VVR-S, owned by the IFIN-HH. In the present paper there are described: the analysis methods and equipment used, the methodologies for calculating doses and the Derived Emission Limits (DEL), the experimentally measured activities of the representative radionuclides found in gaseous and liquid effluents resulted from decommissioning activities, as well as the effective derived limits of liquid and gaseous effluents, applying the calculation methodologies, specific to critical categories of exposed subjects. A constraint effective dose limit for a person from the critical group of 50 μSv/year was considered in calculations. From the comparison of the two series of values, measured released activities and DELs, there has been concluded that for the gaseous effluents they comply with the DELs, while in the case of liquid effluents they are higher and consequently they must be treated as liquid radioactive wastes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Fotokatalytická inaktivace kvasinek v průtočném reaktoru

    OpenAIRE

    Lipenská, Michaela

    2008-01-01

    Tato diplomová práce se zabývá fotokatalytickým účinkem oxidu titaničitého a UV záření. V teoretické části je nastíněn mechanismus působení oxidu titaničitého a jeho aplikace v různých odvětvích. Na kvasince Hansenula anomala byl sledován mikrobicidní účinek oxidu titaničitého ve spojení s UV zářením v průtočném reaktoru. Po zjištění vhodného průtoku byly voleny různé počáteční koncentrace buněk. Pro zvýšení účinku bylo do systému vneseno stříbro, které, jak bylo v mnoha pracech uvedeno, sniž...

  5. Proizvodnja mliječne kiseline na hidrolizatu pšenične slame dobivenom alkalnom predobradom u visokotlačnom reaktoru

    OpenAIRE

    Vidović, Petra

    2017-01-01

    Otpadne lignocelulozne sirovine, u odnosu na šećerne i škrobne sirovine koje se uvelike koriste za prehranu ljudi i životinja, predstavljaju održivu alternativu za proizvodnju biokemikalija kao što je mliječna kiselina. U ovom radu provedena je predobrada pšenične slame s 2 %-tnom natijevom lužinom u visokotlačnom reaktoru pri različitim temperaturama (120°C-210°C) i vremenima zadržavanja od 1 do 20 minuta. Nakon predobrade pšenične slame, dobivene su dvije faze (čvrsta i tekuća faza) te je o...

  6. Otěr minerálních katalyzátorů ve fluidním zplyňovacím reaktoru

    Czech Academy of Sciences Publication Activity Database

    Hartman, Miloslav; Svoboda, Karel; Pohořelý, Michael; Šyc, Michal

    2012-01-01

    Roč. 106, č. 9 (2012), s. 844-846 ISSN 0009-2770 R&D Projects: GA AV ČR IAA400720701 Grant - others:RFCR(XE) CT2010-00009 Institutional support: RVO:67985858 Keywords : gasification of biomass * catalyst attrition * dolomites and limestones Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.453, year: 2012

  7. Spalování kukuřičné slámy v reaktoru s bublinovou fluidní vrstvou.

    OpenAIRE

    Durda, T. (Tomáš); Moško, J. (Jaroslav); Pohořelý, M; Svoboda, K; Zach, B. (Boleslav); Šyc, M. (Michal); Jeremiáš, M. (Michal); Krausová, A. (Aneta); Punčochář, M.

    2016-01-01

    The paper deals with low-temperature bubbling fluidized-bed combustion of corn straw with very low melting point of ash. The research study was focused on influence of change of selected parameters on emissions of pollutants. Parameters that were changed within the tests were: primary fluidized bed material, combustion medium composition and concentration of oxygen in combustion medium. In order to observe influence of investigated combustion characteristics on emissions of pollutants and on ...

  8. CFD analysis and flow model reduction for surfactant production in helix reactor = CFD analiza i redukcija modela strujanja za proizvodnju surfaktanta u helix reaktoru

    NARCIS (Netherlands)

    Nikačević, N.M.; Thielen, L.; Twerda, A.; Hof, P.M.J. van den

    2015-01-01

    Flow pattern analysis in a spiral Helix reactor is conducted, for the application in commercial surfactant production. Step change response curves (SCR) were obtained from numerical tracer experiments by three-dimensional computational fluid dynamics (CFD) simulations. Non-reactive flow is

  9. The use of chemical gel for decontamination during decommissioning of nuclear facilities

    Science.gov (United States)

    Gurau, Daniela; Deju, Radu

    2015-01-01

    A technical research study was developed for testing the decontamination using chemical gels. The study was realized for different type of samples, systems often encountered in the VVR-S nuclear research reactor from Magurele-Romania. The results obtained in the study have demonstrated that the decontamination gels could be an efficient way to reduce or to eliminate the surface contamination of buildings or equipment's, minimizing the potential for spreading contamination during decommissioning activities.

  10. The ΣΣ secondary intermediate-energy standard neutron field development at the Romania TRIGA Reactor

    Science.gov (United States)

    Roth, C.; Gârlea, I.; Dobrea, D.; Aioanei, L.; Kelerman, C.; Gârlea, C.; Gugiu, D.; Datcu, A.; Preda, M.; Pavelescu, M.

    2004-04-01

    The ΣΣ intermediate-energy reference spectrum irradiation facility, operated until 1998 at the VVR-S Reactor from Bucharest, was put into operation at the Romania TRIGA Reactor. This paper presents the experimental devices developed for the ΣΣ system operating at the Steady State Reactor (SSR)-TRIGA core, including the monitoring system, and preliminary neutron characterization results. These results show that the spectrum characteristics are slowly deviating from those for the recommended ΣΣ spectrum. The high-energy neutron tail is slowly increasing, compared with the recommended ΣΣ spectrum and other similar facilities.

  11. Neutron activation analysis of some building materials

    Science.gov (United States)

    Salagean, M. N.; Pantelica, A. I.; Georgescu, I. I.; Muntean, M. I.

    1999-01-01

    Concentrations of As, Au, Ba, Br, Ca, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Mo, Na, Nd, Rb, Sb, Sc, Sr, Ta, Tb, Th, U. Yb, W and Zn in seven Romanian building materials were determined by the Instrumental Neutron Activation Analysis (INAA) method using the VVR-S Reactor of NIPNE- Bucharest. Raw matarials used in cement obtaining ≈ 75% of limestone and ≈ 25% of clay, cement samples from three different factories, furnace slag, phosphogypsum, and a type of brick have been analyzed. The brick was compacted from furnace slay, fly coal ash, phosphogypsum, lime and cement. The U, Th and K concentrations determined in the brick are in agreement with the natural radioactivity measurements of226Ra,232Th and40K. These specific activities were found about twice and 1.5 higher than the accepted levels in the case of226Ra and232Th, as well as40K, respectively. By consequence, the investigated brick is considered a radioactive waste. The rather high content of Co, Cr, K, Th, and Zh in the brick is especially due to the slag and fly ash, the main componets. The presence of U, Th and K in slag is mainly correlated with the limestone and dolomite as fluxes in matallurgy.

  12. Air Shipment of Spent Nuclear Fuel from Romania to Russia

    Energy Technology Data Exchange (ETDEWEB)

    Igor Bolshinsky; Ken Allen; Lucian Biro; Alexander Buchelnikov

    2010-10-01

    Romania successfully completed the world’s first air shipment of spent nuclear fuel transported in Type B(U) casks under existing international laws and without shipment license special exceptions when the last Romanian highly enriched uranium (HEU) spent nuclear fuel was transported to the Russian Federation in June 2009. This air shipment required the design, fabrication, and licensing of special 20 foot freight containers and cask tiedown supports to transport the eighteen TUK 19 shipping casks on a Russian commercial cargo aircraft. The new equipment was certified for transport by road, rail, water, and air to provide multi modal transport capabilities for shipping research reactor spent fuel. The equipment design, safety analyses, and fabrication were performed in the Russian Federation and transport licenses were issued by both the Russian and Romanian regulatory authorities. The spent fuel was transported by truck from the VVR S research reactor to the Bucharest airport, flown by commercial cargo aircraft to the airport at Yekaterinburg, Russia, and then transported by truck to the final destination in a secure nuclear facility at Chelyabinsk, Russia. This shipment of 23.7 kg of HEU was coordinated by the Russian Research Reactor Fuel Return Program (RRRFR), as part of the U.S. Department of Energy Global Threat Reduction Initiative (GTRI), in close cooperation with the Rosatom State Atomic Energy Corporation and the International Atomic Energy Agency, and was managed in Romania by the National Commission for Nuclear Activities Control (CNCAN). This paper describes the planning, shipment preparations, equipment design, and license approvals that resulted in the safe and secure air shipment of this spent nuclear fuel.

  13. Presentation of the results for deuterium retention and thermal release in a new type of low activation ferritic-martensitic steel EUROFER / Результаты исследования по удержанию дейтерия и термической десорбции в условиях низкой активации ферритно-мартенситной стали EUROFER / Rezultati zadržavanja i termalne desorpcije deuterijuma u EUROFER-u, novoj vrsti feritno-martenzitnog čelika niske aktivacije

    Directory of Open Access Journals (Sweden)

    Sanja Lj. Korica

    2016-04-01

    žđu, hromu i EOROFER-u, leguri koja se razmatra kao najnoviji materijal za buduće fuzione reaktore. Studija je pokazala sledeće rezultate: zadržavanje deuterijuma u hromu je mnogo veće nego u gvožđu (usled formiranja hidrida hroma, zadržavanje deuterijuma u EUROFER-u je za faktor 2 veće nego u gvožđu, primećena je specifična struktura u koncentracionom profilu gvožđa i EUROFER-a na dubini ~ 4 μm, veliki stepen difuznosti i zadržavanja deuterijuma govore o potencijalnoj upotrebi Au kao difuzione barijere u fuzionom reaktoru.