Şahin, Sümer
Loading...
Name Variants
Sahin, Suemer
S.,Sumer
Sahin, Sumer
S., Sahin
S., Sumer
S.,Sahin
Sumer, Sahin
S.,Şahin
Ş.,Sümer
Sahin,S.
Şahin, Sümer
Şahin,S.
Sümer, Şahin
S.,Sumer
Sahin, Sumer
S., Sahin
S., Sumer
S.,Sahin
Sumer, Sahin
S.,Şahin
Ş.,Sümer
Sahin,S.
Şahin, Sümer
Şahin,S.
Sümer, Şahin
Job Title
Profesör Doktor
Email Address
ORCID ID
Scopus Author ID
Turkish CoHE Profile ID
Google Scholar ID
WoS Researcher ID
Scholarly Output
42
Articles
23
Citation Count
275
Supervised Theses
0
42 results
Scholarly Output Search Results
Now showing 1 - 10 of 42
Editorial Citation Count: 0Preface to the special issue on "NURER2014: The 4th International Conference on Nuclear and Renewable Energy Resources, 26-29 October 2014, Antalya, Tiirkiye (Turkey)"(Pergamon-elsevier Science Ltd, 2015) Şahin, Sümer; Department of Mechanical Engineering[No Abstract Available]Editorial Citation Count: 0Editorial notes on the 2012 International Youth Nuclear Congress (IYNC), Charlotte, North Carolina, USA (5-11 August 2012)(Pergamon-elsevier Science Ltd, 2013) Şahin, Sümer; Department of Mechanical Engineering[No Abstract Available]Article ‘‘EDITOR’S REPORT’’, IREC 2011, The International Renewable Energy Congress, Hammamet, Tunisia(Energy Conversion and Management, 2011) Şahin, Sümer; Department of Mechanical EngineeringThe Journal of Energy Conversion and Management covers a wide range of topics related to energy such as the energy efficiency and management; heat pipes; thermo-siphons and capillary pumped loops; thermal management of spacecraft; space and ter restrial power systems; hydrogen production and storage; renew able energy; nuclear power; single and combined cycles; miniaturized energy conversion and power systems; fuel cells and advanced batteries; and water management and desalination.Article Citation Count: 3Reactivity and kinetic parameter evolutions for the core height and boron concentration of the fixed bed nuclear reactor(Wiley, 2018) Şahin, Sümer; Do Thi Nguyet Minh; Sahin, Sumer; Truong Huy Hoang; Sefidvash, Farhang; Department of Mechanical EngineeringThis article focuses on calculation of reactivity and kinetic parameters in different states (different core heights and boron concentrations in the coolant water) of the fixed bed nuclear reactor (FBNR). The numerical calculations are performed with the SRAC code. Uranium dioxide (UO2) with U-235 enrichment grade of 5% is used as spherical fuel pellets in the TRISO fuel type. The core height is changed by a core height level limiter. The main results of this study can be summarized as follows: The effective neutron multiplication coefficient is varied with the core height and boron concentration in the coolant water. When there is no-boron in the coolant water and the core height is over 120 cm, the reactor control can be carried out by the movement of a core height level limiter, without the fine control rods in the core center; but when there is a boron concentration, the reactor may be controlled by the level limiter at the lower core heights. The kinetic parameters (the prompt-neutron lifetime and effective delayed neutron fraction) of the reactor also are changed to the reactor core height and to the boron concentration in the coolant water. Copyright (c) 2016 John Wiley & Sons, Ltd.Editorial Citation Count: 1EDITOR'S REPORT, IREC 2011, The International Renewable Energy Congress, Hammamet, Tunisia (December 20-22, 2011)(Pergamon-elsevier Science Ltd, 2012) Şahin, Sümer; Department of Mechanical Engineering[No Abstract Available]Article Citation Count: 25Fissile fuel breeding and minor actinide transmutation in the life engine(Elsevier Science Sa, 2011) Şahin, Sümer; Khan, Mohammad Javed; Ahmed, Rizwan; Department of Mechanical EngineeringProgress on The National Ignition Facility (NIF) brings fusion a viable energy source in foreseeable future. Energy multiplication in a fusion-fission (hybrid) reactor could lead earlier market penetration of fusion energy for commercial utilization. Originally, scientists at the Lawrence Livermore National Laboratory (LLNL) have worked out a hybrid reactor design concept; the so-called Laser Inertial Confinement Fusion-Fission Energy (LIFE) engine, which has consisted of a spherical fusion chamber of similar to 5 m diameter, surrounded by a multi-layered blanket with a beryllium multiplier zone after the first wall. However, earlier work had indicated extreme power peaks at immediate vicinity of the first wall of a hybrid assembly, if a beryllium multiplier is used. Hence, in the current work, the beryllium multiplier zone has been removed in order to mitigate fission power peaks at the vicinity of the first wall as a result of neutron moderation on beryllium. Furthermore, minor actinides (MA) will cause significant neutron multiplication under fusion neutron irradiation so that an extra beryllium multiplier will not be needed. Present work has made following modifications on the LLNL design of the original (LIFE) engine: Omission of beryllium multiplier. TRISO fuel has been suspended as micro-size particles in Flibe coolant in lieu of being dissolved in uranium salt or imbedded carbon matrix in macro-size pebbles. Carbide fuel is used. Fissionable fuel charge is kept lower than in the LLNL (LIFE) engine. The modified (LIFE) engine is kept similar to the LLNL design to a great degree in order to allow mutual feedback between two geographically separated teams towards a more advanced and improved design under consideration of totally independent views. The first wall is made of ODS (2 cm) and followed by a Li17Pbg3 zone (2 cm), acting as neutron multiplier, tritium breeding and front coolant zone. It is separated by an ODS layer (2 cm) from the Flibe molten salt zone (50 cm), containing MA as fissionable fuel. A 3rd ODS layer (2 cm) separates the molten salt zone on the right side from the graphite reflector (30 cm). Calculations have been conducted for a fusion driver power of 500 MWth in S-8-P-3 approximation using 238-neutron groups. Minor actinides (MA) out of the nuclear waste of LWRs are used as fissile carbide fuel in TRISO particles with volume fractions of 0,2,3,4 and 5% have been dispersed homogenously in the Flibe coolant. For these cases, tritium breeding at startup is calculated as TBR= 1.134, 1.286, 1.387, 1.52 and 1.67, respectively. In the course of plant operation, TBR and fissile neutron multiplication factor decrease gradually. For a self-sustained reactor, TBR > 1.05 can be kept for all cases over 8 years. Higher fissionable fuel content in the molten salt leads also to higher blanket energy multiplication, namely M = 3.3, 4.6, 6.15 and 8.1 with 2, 3, 4 and 5% TRISO volume fraction at start up, respectively. For all investigated cases, fissile burn up exceeds 400000 MW D/MT. Major damage mechanisms have been calculated as DPA = 50 and He = 176 appm per year. This implies a replacement of the first wall every 3 years. (C) 2011 Elsevier B.V. All rights reserved.Article Citation Count: 25An innovative nuclear reactor for electricity and desalination(John Wiley & Sons Ltd, 2011) Şahin, Sümer; Sahin, Haci Mehmet; Al-Kusayer, Tawfik Ahmed; Sefidvash, Farhang; Department of Mechanical EngineeringA new era of nuclear energy is emerging through innovative nuclear reactors that are to satisfy the new philosophies and criteria that are being developed by the INPRO program of the International Atomic Energy Agency (IAEA). It is establishing a new paradigm in relation to nuclear energy. The future reactors should meet the new standards in respect to safety, economy, non-proliferation, nuclear waste, and environmental impact. The fixed bed nuclear reactor (FBNR) is a small nuclear reactor that meets all the requirements. It is an inherently safe and passively cooled reactor that is fool proof against nuclear proliferation. It is simple in design and economic. It can serve in a dual purpose plant to produce simultaneously both electricity and desalinated water, thus making it especially suitable to the needs of the Middle-East Countries. FBNR is being developed with the support of the IAEA under its program of small reactors without on-site refueling. The reactor uses the pressurized water reactor technology. It fulfills the objectives of design simplicity, inherent and passive safety, economy, standardization, shop fabrication, easy transportability, and high availability. The inherent safety characteristic of the reactor dispenses with the need for containment; however, a simple underground containment is envisaged for the reactor in order to reduce any adverse visual impact. Copyright (C) 2010 John Wiley & Sons, Ltd.Conference Object Citation Count: 5REDUCTION OF WEAPON GRADE PLUTONIUM INVENTORIES IN A THORIUM BURNER(Amer Nuclear Soc, 2012) Şahin, Sümer; Sahin, Haci Mehmet; Acir, Adem; Department of Mechanical EngineeringLarge quantities of weapon grade (WG) plutonium have been accumulated in the nuclear warheads. Plutonium and heavy water moderator can give a good combination with respect to neutron economy. TRISO type fuel can withstand very high fuel burn up levels. The paper investigates the prospects of utilization of TRISO fuel made of WG-plutonium in CANDU reactors. Three different fuel compositions have been investigated: (1): 90 % ThC + 10 % PuC, (2): 70 % ThC + 30 % PziC and (3): 50 ThC + 50 % PuC. The temporal variation of the criticality k(infinity) and the burn-up values of the reactor have been calculated by full power operation up to 17 years. Calculated startup criticalities for these fuel modes are k(infinity),(0) = 1.6403, 1.7228, 1.7662, respectively. Attainable burn up values and reactor operation times with the same fuel charge will be 94 700, 265 000, 425 000 MW.D/MT and similar to 3.5, 10, 17 years, respectively. These high burn ups would reduce fuel fabrication costs and nuclear waste mass for final disposal per unit energy drastically.Article Report on the special issue SET2012, the 10th International Conference on Sustainable Energy Technologies, _ Istanbul, Türkiye (4–7th September 2011)(Energy Conversion and Management, 2011) Şahin, Sümer; Department of Mechanical EngineeringThe Journal of Energy Conversion and Management covers a wide range of topics related to energy such as the energy efficiency and management; heat pipes; thermo-siphons and capillary pumped loops; thermal management of spacecraft; space and terrestrial power systems; hydrogen production and storage; renewable energy; nuclear power; conventional power; single and combined cycles; miniaturized energy conversion and power systems; fuel cells and advanced batteries; biomass, and water management and desalination.Article Citation Count: 10Neutronic investigations of a laser fusion driven lithium cooled thorium breeder(Pergamon-elsevier Science Ltd, 2014) Şahin, Sümer; Sarer, Basar; Celik, Yurdunaz; Department of Mechanical EngineeringThe paper investigates the main parameters of a Laser Inertial Confinement Fusion Fission Energy (LIFE) driven thorium breeder. A similar blanket to the (LIFE) engine design in Lawrence Livermore National Laboratory is chosen in order to allow mutual feedback between two geographically separated teams towards a more advanced and improved design under consideration of totally independent views. In the basic design, frozen (D,T) fusion fuel ice is shot to the center of 5 m diameter spherical fusion reactor chamber cavity in pulsed mode (10-30 Hz). Fusion fuel burns through direct or indirect laser beam irradiation. The first wall surrounds the fusion chamber and is made of S-304 steel (2 cm). The fusion reactor cavity is kept in high vacuum. It is followed by a natural lithium coolant zone. A 2nd S-304 layer (2 cm) separates the lithium zone on the right side from the graphite reflector (30 cm). The outer boundary of the graphite reflector is also covered with a 3rd S-304 layer (2 cm). The calculations have been performed for a fusion driver power of 500 MWth with the last available version of MCNP, namely with MCNPX-2.7.0. In the first calculation phase, the thickness of the natural lithium coolant-tritium breeder zone (MU has been varied as 50, 60, 70, 80, 90 and 100 cm to select the coolant thickness Delta R-Li; to have a satisfactory tritium breeding ratio (TBR) for continuous fusion reactor operation. For a pure fusion blanket without any fissionable elements in the coolant, TBR values are calculated as 1.237, 1.312, 1.370, 1.415, 1.449 and 1.476, respectively, for corresponding coolant thicknesses. A Delta R-Li value of 50 cm would keep TBR > 1.05 for self-sustaining tritium supply. These Delta R-Li values lead to blanket energy multiplication values of M = 1.209, 1.216, 1.219, 1.222, 1.223 and 1.224, respectively, and have been calculated, as a result of exoenergetic neutron absorption in Li-6. For coolant thickness values >50 cm, the increase of "M" would remain minor. In the second phase, ThO2 has been suspended in the form of micro-size tristructural-isotropic (TRISO) particles in the lithium coolant for U-233 breeding. TRISO fuel has the great advantage of high mechanical stability. Furthermore, fission products will be separated from the coolant. TRISO particles have been dispersed homogenously in the lithium coolant with volume fractions V-tr = 1, 2, 3, 4, 5 and 10 vol-%. Calculations with Delta R-Li = 50 cm and by variable V-tr result with TBR = 1.229, 1.222, 1.214, 1.206, 1.1997 and 1.1622, respectively. Parasitic neutron absorption in Thorium decreases the TBR values. For V-tr < 5 vol-% TRISO in the coolant, the increase of the neutron absorption in thorium will be compensated to a great degree through neutron multiplications via Th-232(n,f) and Th-232(n,2n) reactions so that the sacrifice on TBR remains acceptable. However, for V-tr 5 TRISO vol-%, neutron absorption in thorium reduces TBR drastically. On the other hand, the blanket energy multiplication M increases with thorium volume fraction, namely as M = 1.2206, 1.2322, 1.2426, 1.2536, 1.2636, 1.3112 for respective TRISO volume fractions due to the contribution of fission energy. Fissile fuel productions in the blanket are calculated as 17.23, 33.09, 48.66, 64.21, 79.77 and 159.71 U-233 (kg/year), respectively. (C) 2014 Elsevier Ltd. All rights reserved.
