Yazar "Acir, Adem" seçeneğine göre listele
Listeleniyor 1 - 7 / 7
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Increased fuel burn up in a CANDU thorium reactor using weapon grade plutonium(ELSEVIER SCIENCE SA, 2006) Sahin, Somer; Yildiz, Kadir; Sahin, Haci Mehmet; Sahin, Necmettin; Acir, AdemWeapon grade plutonium is used as a booster fissile fuel material in the form of mixed ThO2/PuO2 fuel in a Canada Deuterium Uranium (CANDU) fuel bundle in order to assure the initial criticality at startup. Two different fuel compositions have been used: (1) 97% thoria (ThO2) + 3PuO(2) and (2) 92% ThO2 + 5% UO2 + 3% PuO2. The latter is used to denaturize the new U-233 fuel with U-238. The temporal variation of the criticality k(infinity) and the burn-up values of the reactor have been calculated by full power operation for a period of 20 years. The criticality starts by k infinity = similar to 1.48 for both fuel compositions. A sharp decrease of the criticality has been observed in the first year as a consequence of rapid plutonium burnout. The criticality becomes quasi constant after the second year and remains above k infinity > 1.06 for similar to 20 years. After the second year, the CANDU reactor begins to operate practically as a thorium burner. Very high burn up could be achieved with the same fuel material (up to 500,000 (MWD)-D-./T), provided that the fuel rod claddings would be replaced periodically (after every 50,000 or 100,000 MW.D/T). The reactor criticality will be sufficient until a great fraction of the thorium fuel is burnt up. This would reduce fuel fabrication costs and nuclear waste mass for final disposal per unit energy drastically. (c) 2006 Elsevier B.V. All rights reserved.Öğe Investigation of effectiveness of different tritium breeding materials in a fusion-fission hybrid reactor fuelled with ThSi 2-moderated with natural Li(2005) Yildiz, Kadir; Acir, AdemIn this work, a fusion-fission reactor fuelling with ThSi 2 is investigated. Natural Li is selected as a moderator in the reactor and Li 2TiO 3, Li 2ZrO 3, Li 4SiO 4 and Li 2O are used in the tritium breeding zones of the reactor. 14.1 MeV D-T neutrons are used as a fusion neutron source. Tritium breeding rates, U breeding rates, fission energy breeding rates and fission power production are investigated for ?t=10 days during a reactor operation period over four years. Using Li 2O in tritium breeding zones of the reactor provided highest tritium breeding rate. Highest value of 233U breeding and production of the fission energy are reached with using of Li 2ZrO 3 in tritium breeding zones of the blanket.Öğe Investigation of Neutronic Performance in Fixed Bed Nuclear Reactor (FBNR) With Fuelled (239Pu/Th)O2(Gazi Univ, 2013) Alkan, Mahmut; Acir, AdemIn this study, the neutronic performance analysis in a fixed bed modular nuclear reactor (FBNR) was performed. The effect of the (Pu-239/Th)O-2 mixture fuel of neutronic performance were investigated. Neutronic calculations were conducted by using SCALES code. Firstly, criticality (k(eff)) value compared 9 % enrichment UO2 was computed. The mixture fuel ratio was obtained as % 6 (PuO2)-Pu-239 + % 94. As a result, the operation times passed until the k(eff) value reached a level of 1.06 was computed as similar to 5 year whereas, the corresponding burnup value wase obtained as similar to 33 000 MWD/T.Öğe Investigation of the Performance of CANDU Reactor Using Different Uranium (Uo2, Uc, U3si2) Fuels(Gazi Univ, 2005) Acir, Adem; Alkan, Mahmut; Baysal, EsrefCanadian Deuterium-Uranium Reactor (CANDU) and Light Water Reactor (LWR) have significant share on supplying world energy. LWRs use low enriched uranium fuel with similar to 3.5 U-235 whereas CANDU utilizes natural uranium fuel with similar to 0.71 % U-235. In this work, neutronic performance of CANDU reactor, temporal change of fissile fuel breeding and fission power production were investigated in the CANDU reactors with different uranium (UO2, UC, U3Si2) fuels. Calculations were done with the aid of one dimensional computer code of SCALE 4.4a. According to calculational results, by taking k(infinity) = 1.06 as reference limit, burnup grades were found as 7700, 8900 and 7400 MW. D/MT and operation periods were obtained as 170, 260, 190 days for these fuels, respectively. According to these results, UC fuel showed better nuclear performance than natural UO2 and U3Si2 fuel with respect to criticality and burn up grade.Öğe The effects of neutron energy-group structures and resonance treatment on integral parameters in a fusion breeder blanket fuelling with ThO2(2005) Şahin, Sümer; Şahin, H. Mehmet; Yildiz, Kadir; Acir, AdemThe purpose of this work is to investigate the effects of neutron energy-group structures and resonance treatments on the main integral neutronic parameters in a fusion-fission hybrid reactor, which has a fast and a thermal blanket fuelling with ThO2. As a neutron source, D-T fusion neutrons (14.1 MeV) are used and fissile zone is cooled (a) with light water for the moderated blanket and (b) with pressurized helium gas for the fast blanket. The neutronic parameters have been evaluated with and without a resonance treatment for the same blanket compositions for the sake of a consistent comparison. Neutron energy-group structures in the neutron libraries and description of fusion neutron source spectrum mainly affect the neutron reactions above a threshold energy in fast neutron groups such as 7Li(n, ?n?)T and 232Th(n,f). These reactions are not affected to resonance treatment. Neutron reactions in the resonance and thermal energy groups are sensitive to resonance treatment, such as 6Li(n,?)T and 232Th(n,?), depending on the resonance structures.Öğe The Effects of the Different Tritium Breeding Materials to Fusil and Fisil Fuel Breeding in a ThSi2 Fuelled- Flibe Moderated Fusion-Fission Hybrid Reactor(Gazi Univ, 2007) Acir, Adem; Yildiz, Kadir; Alkan, Mahmut; Sahin, NecmettinIn this work, in a ThSi2 fuelled-flibe moderated fusion-fission reactor in the tritium breeding zones of the reactor are used four different Li compound, respectively, Li2TiO3, Li2ZrO3, Li4SiO4 and Li2O. D-T fusion reactions are used as a fusion neutron source which produces 14.1 MeV neutrons with averaged energy. Fusil and fissile fuel breeding rates, fission energy breeding rates and fission power production are investigated for Delta t=10 days during a reactor operation period in four years. In tritium breeding zones used Li2O of the reactor provided highest fusil breeding rate whereas, highest value of fissile breeding and production of the fission energy are reached with using of Li2TiO3 and Li2ZrO3 in tritium breeding zones of the blanket.Öğe Uniform nuclear heat density in the CANDU fuel bundle(2004) Şahin, Sümer; Yildiz, Kadir; Acir, Adem[No abstract available]
