Physics is a fundamental science that finds its applications in all areas of our lives. Its application in modern medicine is undeniable. In today’s medical practice special attention is dedicated to the use of ionizing radiation. The wide range of modern science and technology offers enormous possibilities for creation and implementation of new equipment using […]
Volume 21-1
Possibilities for Nuclear Isotopes Production in WWER-1000 type of Reactors for Military Purposes – K. Zashev
Weapons-grade substance is a material with level of enrichment or with characteristic suitable for nuclear bombs production. The most commonly used weapon-grade isotopes in different experiments are uranium-235 and plutonium- 239. It is known that isotopes like uranium-233, neptunium-237 and some isotopes of americium have also been used for the purposes of experimental researches, but […]
Radiation Exposure to the Stuff Working in PET/CT and Cyclotron Facility – S.D. Ivanova
Positron Emission Tomography (PET) has been available in number of centers for more than 25 years, but its use was not wide spread until 10 years ago. In Bulgarian PET/CT was installed for the first time in 2009 and the dose on demand cyclotron also for the first time – in 2013 in Nuclear Medicine Department […]
Management of Ongoing Decommissioning Projects at Kozloduy Nuclear Power Plant Units 1 to 4, Bulgaria – Guarantee for Safe and Timely Decommissioning Process – D. Dishkova
Nuclear safety and security are absolute priorities for the European Union countries and this applies not only to nuclear power plants in operation but also to their decommissioning. The decommissioning process, like any other process with priority to safety and security, must be performed through a clear and achievable strategy. Also in order to minimize the […]
A Sample Application of Nuclear Power Human Resources Model – A. Gurgen, S. Ergun
One of the most important issues for a new comer country initializing the nuclear power plant projects is to have both quantitative and qualitative models for the human resources development. For the quantitative model of human resources development for Turkey, “Nuclear Power Human Resources (NPHR) Model” developed by the Los Alamos National Laboratory was used to […]
Needs of National Infrastructure for Nuclear Energy Program in Macedonia – A. Chaushevski, S.N. Poceva, H. Spasevska, N. Popov
The introduction of a nuclear energy program is a major undertaking with significant implications for many aspects of national infrastructure, ranging from capacity of the power grid, access roads and production facilities, to the involvement of stakeholders and the development of human resources. For new comers countries without nuclear power, even for those who wish to realize […]
Methodology Assessment of the Total Beta Activity in Tobacco and Tobacco Products and Certain Results – A. Georgieva, A. Srentz
The presence of alpha and beta radionuclides in tobacco and tobacco products is a frequently discussed issue. However, any information in publications about them and their presence in tobacco products is too scarce. World Healthcare Organization monitors the influence of tobacco smoking on human health. In 2003, a Framework Convention on Tobacco Control was accepted with the […]
Investigation of Thorium Utilization in a New SMR Core Design – O.S. Çelikten, S. Ergün
Thorium is considered to be a key element in future nuclear technology because of huge amount of reserves in the world. Several investigations have been performed by many of researcher groups around the world for Th-U breeding including the ones in Turkey. In addition, Turkey has one of the biggest thorium reserves in the world, therefore […]
TRANSURANUS Analysis of the Fuel Behaviour under LOCA Conditions – N. Mihaylov, S. Kalburov, S. Boneva, M. Manolova
The move to high burnup fuels, new fuel designs and introduction of new cladding materials have generated a need to re-examine and verify the validity of the safety criteria for LOCA accidents. Fuel designers and nuclear research community, as well as the safety authorities rely on fuel performance codes for predicting the behaviour and life-time of […]
Pin Cell Simulation of the Change in Doppler Broadening and Self-Shielding with the Change in Nuclear Fuel Temperature and Fuel Type by Using OpenMC – N. Beydogan, G. Konur, G. Sarici, O.S. Çelikten, M. Türkmen, C.N. Sökmen
The main purpose of this study is to determine the uncertainties in modelling due to use of isothermal temperature assumption in the radial direction. For this purpose, unit cells specified in the OECD/NEA LightWater Reactor (LWR) Uncertainty Analysis in Modeling (UAM) benchmark, BWRPeach Bottom-2, the PWRunit cell of Three-Mile Island-1 and the VVER Kozloduy-6, are […]
Performance Optimization and Validation for the PRHRS of VVERs with RELAP5 Code – H. Ayhan, C.N. Sökmen
Passive safety systems are considered as the systems which improve safety and reliability of the Nuclear Power Plants (NPP). Although they seem helpful, for the nuclear technology, passive systems require special attention, because of the disadvantages for their use due to the large difficulties in the thermal-hydraulic design compared with the active systems. One of the important dynamics […]
Investigation of Heat Transfer and Turbulence Characteristics of a Triangular Rod Array in lattice-Boltzmann Framework – A. Tiftikci, C. Kocar
In present study, triangular subchannel of VVER-440 reactor is simulated using with lattice-Boltzmann and finite volume methods. The heat transfer and flow characteristics such as pressure drop, heat transfer coefficient, temperature and velocity distributions are obtained by using both LBM and FVM. The selected VVER subchannel has pitch-to-diameter ratio of 1.35. Simulations are carried out in two stages: […]
Investigation of IVMR Strategy with External Vessel Bottom Head Water Cooling in VVER1000/v320 Reactor Design with ASTECv2.1.0.3 Computer Code – R. Gencheva, A. Stefanova, P. Groudev
During a severe accident a large quantity of molten core material may relocate to the lower plenum of the reactor pressure vessel, where it starts to interact with the stainless steel of the vessel. This causes heat up of the lower head vessel and its eventual failure.In-vessel melt retention strategy through external cooling of the reactor vessel is one […]
Numerical Investigation of the Possibility for “Dry” Recriticality of the Molten Corium during Late In-Vessel Phase of Severe Accident at LWR – D. Popov, O. Runeval
During a hypothetical severe accident with LWR, a molten corium pool would be formed in RPV bottom head containing large amount of fissile material as tons of Uranium and hundred kilograms of Plutonium for EOC. Extensive part of these are oxidized, but some part is transformed into pure heavy metals, due to high temperature chemical interactions between molten […]