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Selected aspects of the choice of live steam pressure in PWR nuclear power plant

Laskowski Rafał, Smyk Adam, Jurkowski Romuald, Ancé Julien, Wołowicz Marcin, Uzunow Nikołaj

Archives of Thermodynamics

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2022

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Vol. 43, no 3

85--109

EN

In commercially available generation III and III+ PWR (pressurized water reactor) reactors, pressure of steam produced in steam generators varies in a relatively wide range from 5.7 to 7.8 MPa. Therefore, it is important to ask which value of steam pressure should be used for a specific unit, taking into account different location conditions, the size of the power system and conditions of operation with other sources of electricity generation. The paper analyzes the effect of steam pressure at the outlet of a steam generator on the performance of a PWR nuclear power plant by presenting changes in gross and net power and efficiency of the unit for steam pressures in the range of 6.8 to 7.8 MPa. In order to determine losses in the thermal system of the PWR power plant, in particular those caused by flow resistance and live steam throttling between the steam generator and the turbine inlet, results concerning entropy generation in the thermal system of the power plant have been presented. A model of a nuclear power plant was developed using the Ebsilon software and validated based on data concerning the Olkiluoto Unit 3 EPR (evolutionary power reactor) power plant. The calculations in the model were done for design conditions and for a constant thermal power of the steam generator. Under nominal conditions of the Olkiluoto Unit 3 EPR power unit, steam pressure is about 7.8 MPa and the steam dryness fraction is 0.997. The analysis indicates that in the assumed range of live steam pressure the gross power output and efficiency increase by 32 MW and 0.735 percentage point, respectively, and the net power output and efficiency increase by 27.8 MW and 0.638 percentage point, respectively. In the case of all types of commercially available PWR reactors, water pressure in the primary circuit is in the range of 15.5−16.0 MPa. For such pressure, reducing the live steam pressure leads to a reduction in the efficiency of the unit. Although a higher steam pressure increases the efficiency of the system, it is necessary to take into account the limitations resulting from technical and economic criteria as well as operating conditions of the primary circuit, including the necessary DNBR (departure from nucleate boiling ratio) margin. For the above reasons, increasing the live steam pressure above 7.8 MPa (the value used in EPR units that have already been completed) is unjustified, as it is associated with higher costs of the steam generator and the high-pressure part of the turbine.

2

Operacyjna likwidacja skażeń

Harmata Władysław

Biuletyn Wojskowej Akademii Technicznej

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2020

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Vol. 69, nr 2

71--91

PL

W pracy scharakteryzowano operacyjną likwidację skażeń jako system zabezpieczenia wojsk w przypadku zagrożenia skażeniami w ujęciu funkcjonalnym i zadaniowym. Przedstawiono krytyczną analizę wyposażenia technicznego oraz procedur postępowania po skażeniach.

EN

The paper describes the operational decontamination as a system for protection of troops in case of threat of contamination in functional and task-related terms. A critical analysis of technical equipment and post-contamination procedures is presented.

3

Development of nuclear power as an alternative to fossil fuels

Michalski Marek

Acta Innovations

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2019

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no. 30

38--47

EN

Research into environmental pollution and global warming has induced the energy industry and various levels of government to reduce their dependence on fossil fuels, especially coal and oil. One of the options being considered is increasing nuclear power generation, which has the advantage of high production capacity that can be fully utilized, low fuel consumption and low cost relative to the amount of electricity being generated. However, despite technological progress, the share of nuclear energy in the world’s energy mix is decreasing, especially in countries with highly developed economies. The reasons for this are high capital expenditures and their uncontrolled increase, fear of contamination of the natural environment in the event of a failure or terrorist attack as well as difficulties in long-term disposal of radioactive waste. This article analyzes the development of nuclear power as an alternative to fossil fuels in the pursuit of sustainable development, in particular with regard to investment outlays, the cost of generating electricity, environmental protection and security.

4

Problemy likwidacji skażeń

Harmata W.

Biuletyn Wojskowej Akademii Technicznej

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2018

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Vol. 67, nr 4

207--231

PL

W pracy scharakteryzowano likwidację skażeń jako system zabezpieczenia wojsk w przypadku zagrożenia skażeniami w ujęciu funkcjonalnym i zadaniowym. Przedstawiono krytyczną analizę wyposażenia technicznego oraz procedur postępowania po skażeniach.

EN

The work describes the elimination of contamination as a system for securing troops in the event of contamination in a functional and task approach. A critical analysis of technical equipment and post-contamination procedures was presented.

5

Sources of natural background radiation

Dolchinkov N. T.

Security and Defence Quarterly

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2017

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Vol. 16, No. 3

40--51

EN

After the major accidents in “Chernobyl” NPP, located on the territory of present-day Ukraine, and then in the USSR in April 1986, in Bulgaria, as well as in most European countries a lack of systems for a continuous measurement of gamma radiation was reported, which have to provide reliable real-time information on radiation status. Consequently, in the European Union, construction of automated systems for continuous monitoring of gamma radiation has begun. Observations on the state of the radiation background in Bulgaria are carried out in parallel in two ways. A serious problem can cause people to cross a state border in random unregulated places and not at a checkpoint.

6

Scenariusz średnich kosztów energii elektrycznej do roku 2050 oraz cen w taryfach za energię elektryczną dla wybranych grup odbiorców do roku 2030

Wiśniewski G., Curkowski A., Pejas B.

Energetyka – Społeczeństwo – Polityka

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2017

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nr 2(6)

53--80

EN

A model of prices and tariffs for the Polish power system was developed, which allows assessment of the effects of public policy in the energy sector from the point of view of energy costs for the economy and for selected group of consumers. Modelling results can be used to assess the market and economic effects of individual scenarios, energy concepts or regulatory impact assessment. The model with the forecast of costs and energy prices allows to analyse the potential impact of the introduction or exclusion from the national energy system of a specific group of technologies or central power plant on electricity costs. The results of the analysis indicate the inevitability of the increase of energy costs. Domestic energy policy leads to an increase in operating costs and, as a result, to an increase in total costs in the power generation sector from PLN 37 billion in 2015 to PLN 68 billion in 2030, which will translate into an increase in tariffs for small and medium enterprises and households.

7

Importance of advanced planning of manufacturing for nuclear industry

Shykinov N., Rulko R., Mroz D.

Management and Production Engineering Review

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2016

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Vol. 7, No. 2

42--49

EN

In the context of energy demands by growing economies, climate changes, fossil fuel pricing volatility, and improved safety and performance of nuclear power plants, many countries express interest in expanding or acquiring nuclear power capacity. In the light of the increased interest in expanding nuclear power the supply chain for nuclear power projects has received more attention in recent years. The importance of the advanced planning of procurement and manufacturing of components of nuclear facilities is critical for these projects. Many of these components are often referred to as long-lead items. They may be equipment, products and systems that are identified to have a delivery time long enough to affect directly the overall timing of a project. In order to avoid negatively affecting the project schedule, these items may need to be sourced out or manufactured years before the beginning of the project. For nuclear facilities, long-lead items include physical components such as large pressure vessels, instrumentation and controls. They may also mean programs and management systems important to the safety of the facility. Authorized nuclear operator training, site evaluation programs, and procurement are some of the examples. The nuclear power industry must often meet very demanding construction and commissioning timelines, and proper advanced planning of the long-lead items helps manage risks to project completion time. For nuclear components there are regulatory and licensing considerations that need to be considered. A national nuclear regulator must be involved early to ensure the components will meet the national legal regulatory requirements. This paper will discuss timing considerations to address the regulatory compliance of nuclear long-lead items.

8

Monte-Carlo aided design of neutron shielding concretes

Tefelski D., Piotrowski T., Polański A., Skubalski J., Blideanu V.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2013

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Vol. 61, nr 1

161-171

EN

The process of design of building composites, like concrete is a complex one and involves many aspects like physical and mechanical properties, durability, shielding efficiency, costs of production and dismantlement etc. There are plenty of parameters to optimize and computer tools can help to choose the best solution. A computer aided design plays an important role nowadays. It becomes more accurate, faster and cheaper, so laboratories often apply computer simulation methods prior to field testing. In case of nuclear engineering, the radiation shielding problems are of much importance, because safety of such facilities is a key point. In this article the most effective methods for neutron shielding studies based on Monte-Carlo simulations of neutron transport and nuclide activation studies in concrete are presented. Two codes: MCNPX and CINDER’90 are extensively used to compare the shielding efficiency of commonly used concretes and to study the influence of concentration of B, Ba and Fe elements on shielding efficiency.

9

Technologie wytwórcze dla zapewnienia bezpieczeństwa elektroenergetycznego kraju

Pawlik M.

Wiadomości Elektrotechniczne

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2006

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nr 6

31-39

PL

Przedstawiono analizę dostępnych technologii niezbędnych do odtworzenia rozbudowy mocy wytwórczych krajowych elektrowni oraz omówiono uwarunkowania rozwoju technologii wytwórczych: węglowej, gazowej i jądrowej.

EN

The paper presents analysis of available technologies needed to regenerate and develop the production capacity of national power stations. Conditions for development of coal, gas and nuclear technologies are also discussed.

10

Simulation of the MARA 10 test representing a core disruptive accident

Robbe M. F., Lepareux M., Casadei F.

Computer Assisted Mechanics and Engineering Sciences

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2006

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Vol. 13, No. 2

269-304

EN

In the case of a Hypothetical Core Disruptive Accident in a Liquid Metal Fast Breeder Reactor, the core of the nuclear reactor is assumed to have partially melted, and the interaction between molten fuel and liquid sodium creates a high-pressure gas bubble in the core. The violent expansion of this bubble loads and deforms the reactor vessel and the internal structures, thus endangering the safety of the nuclear plant. The MARA 10 experimental test simulates a HCDA in a 1/30-scale mock-up schematising simply a reactor block. The vessel is filled with water, topped with an air blanket. The test is fired using an explosive charge. This paper presents the numerical models implemented in the EUROPLEXUS code, and a numerical simulation of the test. The evolution of the fluid flows and the deformations of structures are analysed in detail to understand the progress of the explosive phenomenon.