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[en] This book is an updated version of a previous document published in 2013. It aims at giving detailed information on the nature of waters used by nuclear power plants and of their releases, on how intakes are performed and controlled, on the associated risks for the environment and public health, and on how public is informed. After a general overview of these issues, a chapter addresses the protection of nature and biodiversity and the actions performed by EDF in this respect. The next chapters deal with public information, legal and regulatory aspects and the role of administration. Then, the water needs of a nuclear power plant, the nature and monitoring of effluents, the impacts of water intakes and effluents are addressed. Finally, the monitoring and control of the environment, and the various techniques of environmental metrology are presented
[en] Hearing the words ‘nuclear power’ usually conjures up images of huge power plants and cooling towers, but with small modular reactors (SMRs) and microreactors (MRs) starting to become a reality, the face and reach of nuclear power is changing. SMRs are expected to generate up to 300 megawatts (electrical) (MW(e)) of power and MRs up to 10 MW(e), depending on their designs. In addition to their modularity, some other common features are passive and built-in systems that enhance safety, the ability to efficiently and flexibly generate energy to meet fluctuating demands, and simpler designs that are faster and less complex to construct than current reactors. They also have more factory-based manufacturing possibilities, which can reduce on-site construction time and makes them easier and more cost-effective to reproduce for additional deployment.
[en] This paper discusses the transfer process, limited about heat and mass, in the cooling tower fill.. In this research has been measured some parameters. There is the dry-bulb temperature at the bottom fill, ambient relative humidity, air stream velocity entering fill, dry bulb temperature leaving the fill, the relative humidity of air leaving the fill, inlet and outlet water temperature of the cooling tower. Data is used for practical calculations. Then, heat and mass transfer calculations are calculated based on the proposed approach.The results are compared with the design data. The design and analogy method showed a different result. The parameter which influences the heat transfer at the cooling tower is represented by the coefficient of heat transfer hl and coefficient of mass transfer kl. The differences result between the design and analogy method shows that there is an important parameter which different. Deeply study needed for it. (author)
[en] A new air-cooled waste heat removal system with a direct contact heat exchanger was designed for SMRs requiring 200 MW of waste heat removal. Conventional air-cooled systems use fin structure causing high thermal resistance; therefore, a large cooling tower is required. The new design replaces the fin structure with a vertical string type direct contact heat exchanger which has the most effective performance among tested heat exchangers in a previous study. The design results showed that the new system requires a cooling tower 50% smaller than that of the conventional system. However, droplet formation on a falling film along a string caused by Rayleigh-Plateau instability decreases heat removal performance of the new system. Analysis of Rayleigh-Plateau instability considering drag force on the falling film surface was developed. The analysis results showed that the instability can be prevented by providing thick string. The instability is prevented when the string radius exceeds the capillary length of liquid by a factor of 0.257 under stagnant air and 0.260 under 5 m/s air velocity.
[en] In response to new standard for regulating research and test reactor which is enforced December 18, 2013, it was carried out assessment of the probability of aircraft crashing for HTTR. According to assessment method provided in the “Assessment Criteria of the Probability of Aircraft Crashing on Commercial Power Reactor Facilities”, assessment was conducted targeting reactor building, spent fuel storage building and cooling tower. As a result, it was confirmed that the probability was 5.98×10-8, which is lower than the assessment criteria 10-7. (author)
[en] The peaceful use of nuclear energy was the most momentous utopian technical undertaking in German post-war history and led to one of the country's greatest social conflicts. Although iconic domes and cooling towers have become symbols of this technology, the rest of the nuclear world is practically invisible. Over a period of seven years, Bernhard Ludewig photographed both the buildings and the processes carried out within them - predominantly in Germany but also elsewhere in Europe and in South America. His enlightening images provide a rare glimpse behind the scenes: power plants and open reactors, cooling towers and control rooms, uranium centrifuges and repositories, research reactors and Cherenkov radiation, construction and demolition. The Nuclear Dream reveals a world that is now on the decline in Germany yet once promised an unlimited supply of energy.
[de]Die friedliche Nutzung der Kernenergie war die folgenreichste technische Utopie der deutschen Nachkriegsgeschichte und führte zu einem ihrer größten gesellschaftlichen Konflikte. Während die ikonischen Kuppeln und Kühltürme zum Symbol wurden, ist der Rest der nuklearen Welt praktisch unsichtbar. Bernhard Ludewig hat ihre Orte und Arbeitsschritte über sieben Jahre fotografiert – vor allem in Deutschland, aber auch anderswo in Europa und in Südamerika. Seine Bilder gewähren einen einzigartigen Blick hinter die Kulissen: Kraftwerke und offene Reaktoren, Kühltürme und Kontrollräume, Uranzentrifugen und Endlager, Forschung und blaues Leuchten, Bau und Abriss. Der nukleare Traum zeigt eine in Deutschland verschwindende Technikwelt, die einst grenzenlose Energie versprach.
[en] This paper describes verifying the determination of the 12 MeV nominal energy beam electron water absorption dose emitted from the Elekta Versa HD / 154714 medical linear accelerator owned by Mayapada Hospital, Leak Bulus, Jakarta. Measurements were done in the 1D water phantom Scanner under reference conditions with the source to surface distance 100 cm and the standard field size using the applicator 10 cm x 10 cm and the depth corresponding to (0.6 R50 -0.1) cm.The IBA CC13 ionization chamber was used as a radiation measurement instrument for PDD measurements, while the Rods plane-parallel ionization chamber was used for absolute measurements. Rod's parallel ionization chamber was connected with PTKMR-BATAN's PTW Unidose Webline electrometer. This ionization chamber was also traced to the primary standard laboratory of BIPM, France. Meanwhile, the PCC40 plane-parallel ionization chamber was connected with a Dose 1 electrometer owned by Mayapada Hospital, which was traced to the PTB primary standard laboratory. Calculation of measurement results was carried out using the IAEA dosimetry protocol contained in Technical Report Series No. 398. The results obtained indicate a fairly good fit between the two measurements with a difference of 0.3 %. (author)
[en] One important component of the reactor coolant system is the cooling tower. The RSG-GAS cooling tower has been operated for more than 30 years. The study of the performance of cooling towers has been carried out at a nominal power operation of 30 MW in terms of the safety of reactor operations. The study was conducted to determine the performance of cooling towers in removing heat into the environment. Parameters for evaluating the performance of cooling towers used include the range, approach, effectiveness, efficiency and coolant temperature entering the reactor core. From a 1992 operational data study, a range value of 7,2 oC was obtained, the approach value of 8,0 oC, the effectiveness value of 47.37 %, and the temperature of the cooling inlet temperature was 40.0 oC. From a 2018 operational data study, the range value of 6.7 oC was obtained, the approach value of 9.3 oC, the effectiveness value of 41.84 %, and the cooling inlet temperature value was 41.96 oC. The value of the cooling temperature entering the core in 1992 was below the reactor protection system activation limit, while the value of the cooling temperature entering the core in 2018 approached the reactor protection system activation limit. It can be concluded that the performance of cooling towers after 30 years operation cannot meet the safety criteria of reactor operations. (author)
[en] In this research, a series of experiments have been performed to study the thermal resistance of an oscillating heat pipe equipped with cooling tower. The effects of filling ratio and input heating power on the thermal resistance of the heat pipe and temperatures of different sections of evaporator and condenser of the heat pipe are investigated and discussed. All tests are taken for input heating power and filling ratio in the ranges of 20–200 W and 10–60%, respectively. A correlation for the thermal resistance is presented, which the effects of input heating power and filling ratio are taken into account in this correlation. The results showed that the heat pipe with filling ratio of 40% and input heating power of 160 W has the minimum value of thermal resistance among all cases considered in this research. Moreover, the thermal resistance decreases about 86% as the input heating power increases in the range of 20–120 W, while this reduction is only 23% by increasing the input heating power in the range of 160–200 W.
[en] MARIA research reactor is operated by the National Centre for Nuclear Research in Świerk, Otwock, near the capital of Poland (Warsaw). It is a high flux research reactor with a thermal neutron flux density of 4 × 1014 cm-2s-1, and 3 × 1013 cm-2s-1 in the case of fast neutrons. Both values correspond with the nominal thermal power of 30 MW(th). MARIA uses low enriched uranium (LEU) fuel elements with 235U enrichment: 19.75% or 19.7% in the form of U3Si2 or UO2 dispersed in aluminium (two types of fuel). MARIA is a hybrid pool-type/channel-type reactor. The fuel elements are settled inside pressurized channels which are located between beryllium blocks, in a rectangular lattice. The number of fuel channels depends on the reactor operating demands; the safety limits determine the maximum power of 1.8 MW(th) per fuel element. The reactor is equipped with two independent primary cooling loops: a fuel channel cooling system and a pool cooling system. Each of the fuel channels is cooled independently with a controlled flow rate and inlet and outlet coolant temperatures. The two cooling loops are connected to a secondary cooling system that removes heat through the wet cooling towers with a mechanical draught. The detailed parameters of the secondary cooling circuit are presented.