Decay heat
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Part 2 book "Air conditioning engineering" includes contents: Cooling load, the fundamentals of vapour compression refrigeration, air cooler coils, the rejection of heat from condensers and cooling towers, refrigeration plant, automatic controls, vapour absorption refrigeration, airflow in ducts and fan performance, ventilation and a decay equation, filtration.
301p dianmotminh01 14-05-2024 1 0 Download
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The VVER-1000 reactors are nowadays widespread used in Russia and numerous countries. With almost 3000 MW of thermal, VVER-1000 is a candidate to transmute minor actinides (MAs) which are the main contributors to the radiotoxicity and decay heat of nuclear spent fuel (SNF).
11p visnape 30-01-2023 8 4 Download
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Disposal of spent nuclear fuel is a major political and public-perception problem for nuclear energy. From a radiological standpoint, the long-lived component of spent nuclear fuel primarily consists of transuranic (TRU) isotopes.
13p vironald 15-12-2022 17 6 Download
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Full recycling of transuranic (TRU) isotopes can in theory lead to a reduction in repository radiotoxicity to reference levels in as little as ~500 years provided reprocessing and fuel fabrication losses are limited. However, over a limited timeframe, the radiotoxicity of the ‘final’ core can dominate over reprocessing losses, leading to a much lower reduction in radiotoxicity compared to that achievable at equilibrium.
12p vironald 15-12-2022 13 4 Download
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In this study, an optimization of the canister loading for used nuclear fuels is performed, solely based on their decay heat values. By taking into account the individual irradiation history for each fuel assembly, as well as with a number of assumptions on the number of used fuels to be disposed, this study indicates that a canister filling fraction of 94% is achievable for both PWR and BWR fuel, thus lowering the number of required canisters compared to a previous study.
11p vironald 15-12-2022 10 4 Download
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The assessment in this paper is necessary to demonstrate that sufficient decay heat conservatism is retained in the UNF-ST&DARDS bounding as-loaded spent fuel analysis methodology. This paper also demonstrates the time dependent impact of various parameters such as last cycle power on decay heat values.
25p vironald 15-12-2022 6 3 Download
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In the present paper, firstly, we review our previous works on uncertainty quantification (UQ) of reactor physics parameters. This consists of (1) development of numerical tools based on the depletion perturbation theory (DPT), (2) linearity of reactor physics parameters to nuclear data, (3) UQ of decay heat and its reduction, and (4) correlation between decay heat and b-delayed neutrons emission.
7p christabelhuynh 29-05-2020 11 1 Download
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This paper presents a study of the impact of the nuclear data (cross sections, neutron emission and spectra) on different quantities for spent nuclear fuels (SNF) from Swiss power plants: activities, decay heat, neutron and gamma sources and isotopic vectors.
15p christabelhuynh 29-05-2020 4 1 Download
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This paper focuses on the strategy that could be used to resolve this issue with the complement and the exploitation of the DARWIN2.3 experimental validation.
10p christabelhuynh 29-05-2020 8 1 Download
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Pear cv. Nashpati were subjected to three treatments viz. T1 (Individual Shrink wrapping), T2 (Shrink Wrapping in trays) and T3(Control treatment) were stored in ambient condition (29-32oC temperature and 55-78% relative humidity) in which periodical observations were recorded on physiological loss in weight (PLW, %), total soluble solid (TSS, °Brix), titratable acidity (mg of malic acid/g), decay loss (%) and sensory quality (%) at Department of Post-Harvest Management, College of Horticulture and Forestry, Arunachal Pradesh, India during the year 2017-2018.
7p angicungduoc4 26-04-2020 5 0 Download
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The experimental results showed that the natural circulation system is feasible in removing the decay heat, even though some fluctuations may occur in the operation. The uneven temperature distribution in the water tank may be inevitable because convection occurs on the outside of the condensing tube besides boiling with decreasing the decay power. The instabilities in the natural circulation loop are sensitive to heat flux and system resistance rather than the water level in the steam drum and water tank. RELAP5 code shows reasonable results compared with experimental data.
9p minhxaminhyeu5 30-06-2019 19 1 Download
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The pressure inside the containment does not exceed the design pressure even after 10 days by condensation of steam generated from the GDWP on the walls of containment and on the Passive Containment Cooling System (PCCS) tubes. If venting is carried out after this period, the decay heat can be removed for more than 50 days without exceeding the design limits.
8p minhxaminhyeu5 30-06-2019 11 0 Download
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The advanced passive pressurized water reactor (PWR) is being constructed in China and the passive residual heat removal (PRHR) system was designed to remove the decay heat. During accident scenarios with increase of heat removal from the primary coolant system, the actuation of the PRHR will enhance the cooldown of the primary coolant system. There is a risk of power excursion during the cooldown of the primary coolant system. Therefore, it is necessary to analyze the thermal hydraulic behavior of the reactor coolant system (RCS) at this condition.
9p minhxaminhyeu5 30-06-2019 16 1 Download
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Twenty sodium-cooled fast reactors (SFRs) have provided valuable experience in design, licensing, and operation. This paper summarizes the important safety criteria and safety guidelines of intermediate sodium systems, steam generators, decay heat removal systems and associated construction materials and in-service inspection. The safety criteria and guidelines provide a sufficient framework for design and licensing, in particular by new entrants in SFRs.
7p minhxaminhyeu5 30-06-2019 22 1 Download
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The main results of the research described are the following: (1) following the research on the influence of mixed fuel fission products (radioactive isotopes being formed during reactor operation as a result of nuclear decay of elements included into the fuel composition) on living organisms, the authors determined the quantities of plutonium dioxide (РuO2) that penetrated into blood and lay in the pulmonary region, liver, skeleton and other tissues.
11p minhxaminhyeu5 30-06-2019 20 1 Download
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The simulation contains two phases based on water depletion: the early phase and the late phase. In the early phase, the volume of water in PCCT was determined to avoid the water depletion in three days after shutdown. In the late phase, when the number of the HXs is greater than 4089 per PCCT, the MARS simulation confirmed the long-term cooling by air is possible under extended Station Blackout (SBO).
13p minhxaminhyeu3 12-06-2019 9 1 Download
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The geometrical and electromagnetic variables of a rectangular-type magnetohydrodynamic (MHD) circulation system are optimized to solve MHD equations for the active decay heat removal system of a prototype Gen-IV sodium fast reactor. Decay heat must be actively removed from the reactor coolant to prevent the reactor system from exceeding its temperature limit. A rectangular-type MHD circulation system is adopted to remove this heat via an active system that produces developed pressure through the Lorentz force of the circulating sodium.
11p minhxaminhyeu3 12-06-2019 18 2 Download
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Chương trình DHP (Decay Heat Power) tính toán công suất nhiệt phân rã từ các sản phẩm phân hạch hạt nhân đã được nhóm nghiên cứu của Viện Nghiên cứu hạt nhân (NCHN) phát triển có sự hợp tác với chuyên gia từ Cơ quan Năng lượng nguyên tử Nhật Bản (JAEA) thông qua chương trình hợp tác với Bộ Giáo dục, Văn hóa, Thể thao và Khoa học và Công nghệ Nhật Bản (MEXT).
4p vicross2711 26-06-2019 31 1 Download
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AbstractHumidity is one of the main causes of decay in buildings, particularly rising damp, caused by the migration of moisture from the ground through the materials of the walls and floors via capillary action. This water comes from groundwater and surface water. The height that moisture will reach through cap illary action depends upon factors such as the quantity of water in contact with the particular part of the building, surface evaporation conditions, wall thickness, building orientation and the presence of salts.
270p namde04 02-05-2013 65 9 Download
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I. Introduction An important aspect of nuclear reactor core analysis involves the determination of the optimal coolant flow distribution and pressure drop across the reactor core. On the one hand, higher coolant flow rates will lead to better heat transfer coefficients and higher Critical Heat Flux (CHF) limits. On the other hand, higher flows rates will also in large pressure drops across the reactor core, hence larger required pumping powers and larger dynamic loads on the core components.
259p giotletinh_hd2009 20-04-2013 89 18 Download