scholarly journals A contribution to evaluation of nuclear power plants competitiveness using 3E indicator: One possible approach

2019 ◽  
Vol 23 (6 Part B) ◽  
pp. 4095-4105
Author(s):  
Vojin Grkovic ◽  
Djordjije Doder

The strong restrictions of greenhouse gasses emissions and the high penetration of intermittent renewable energy sources are the frame for researching more closely the contribution of nuclear power plants to competitiveness of corresponding technology portfolio for electricity generation. For the competitiveness indication 3E indicator is applied. The 3E indicator is expressed as the function of two variables that indicate the configuration of the technology portfolio i. e. participation of intermittent renewables in covering overall electricity load and participation of nuclear power plants in covering the residual electricity load. Obtained results point out that an increase of nuclear power plants participation in residual load contributes to the increase of the technology portfolio?s competitiveness, i. e. to the reduction of the 3E indicator?s numerical value. On the other hand, an increase of intermittent renewables participation in overall load in principle contributes to the decrease of the technology portfolio?s competitiveness, i. e. to the increase of the 3E indicator?s numerical value with the maximal value at the certain participation rate. The competitiveness of the technology portfolios for electricity generation in eleven European countries is also examined. The results point out that the country with highest participation of intermittent renewables in overall load domain has the less favorable competitiveness, and the lowest annual equivalent operation time of the technology portfolio. On the other hand, the country with highest participation of nuclear power plants in residual load domain has the most favorable value of 3E indicator and the highest annual equivalent operation time of its technology portfolio.

1988 ◽  
Vol 24 (1-4) ◽  
pp. 143-147 ◽  
Author(s):  
B. Descamps ◽  
L. Foulquier

Abstract The study is based on data covering the water, sediments, plants and fish sampled over a 20-year period at 15 stations along French rivers. Three geographic zones were investigated: one containing a uranium mining complex (Zone 1), another including five major rivers along which nuclear power plants are sited (Zone II) and a third unaffected by nuclear activities (Zone III). Natural radioactivity basically involves 238U, 226Ra and 210Pb in the uranium series, 232Th from the thorium series, 40K and 7Be. The natural radioactivity in Zone II is not different from Zone III, and is thus unaffected by waste discharges from nuclear power plants. The most abundant radionuclide is 40K, while the other nuclides are often found in trace amounts near the detection threshold of the analysis method used (Ge gamma spectrometry with a 15-hour counting period). The 226Ra and 238U concentrations observed in Zone I are at least an order of magnitude higher than in the other two zones due to authorised waste discharges from the Lodève mining complex, but only a small stream is affected. The measured 226Ra concentrations would result in an annual whole body committed dose equivalent attributable to a 200 g weekly fish consumption from this stream of 4.4 x 10-5 Sv.y-1, or 0.86% of the maximum permissible dose (5 mSv).


2020 ◽  
Vol 15 (28) ◽  
pp. 344-375
Author(s):  
Anita Paulovics

This paper is about the legal regulation of the extension of the operation time of nuclear power plants.  In Hungary the most important document in this respect has been the National Energy Strategy analyzed in the paper. In Hungary, the legal regulation of the extension of the time limit of the operation-permit of nuclear power plants is modelled on that of the United States. For this reason, the paper examines the rules in force in the USA on the extension of the operation time.  It could be of interest for several European countries considering to extend the operation time of their nuclear power plants.


Author(s):  
Ф.О. Аракелян ◽  
И.П. Башилов ◽  
Ю.Н. Зубко ◽  
А.В. Николаев ◽  
Д.Г. Левченко

Рассмотрено состояние и перспективы развития атомной энергетики в связи с сейсмической и другими природнотехногенными опасностями. Анализирован опыт эксплуатации АЭС, статистика аварий на АЭС, их причины. В связи с авариями на ряде АЭС и глобальной сменой приоритетов энергетической политики в сторону возобновляемых источников энергии (ветра, солнца, гейзеров и т.п.) многие из технически развитых стран (США, Япония, Германия) заявляют о снижении роли атомной энергетики в собственных энергетических планах. Угроза опасности объединяет усилия таких стран как США, Франция, Россия, Япония, Южная Корея, Канада и Китай в сотрудничестве в области совершенствования технологий, усиления ядерной безопасности и развития ядерной инфраструктуры в странахновичках. Наиболее опасными признаны АЭС Азии, где отмечается повышенная сейсмичность. Благодаря усилиям по повышению безопасности АЭС, сделан вывод о снижении сейсмической опасности в связи с глубокой автоматизацией и передачей основных управляющих функций АЭС программному комплексу, совершенствованием алгоритмов принятия решений в случае землетрясения и других чрезвычайных ситуаций. Одна из главных целей глубоко эшелонированной защиты состоит в блокировании опасностей человеческих ошибок и сочетания отказов оборудования и ошибок операторов и распорядителей. Системы безопасности должны включаться автоматически и на некоторое время блокировать действия оператора АЭС. Эффективной защитой энергоблоков, построенных в последние десятилетия, являются герметичные оболочки (контейменты) и размещение над реактором емкости с большим количеством раствора бора, который выливается на реактор при аварии и нейтрализует радиоактивность в случае ее появления. Более детальный анализ сейсмотектонической ситуации площадок действующих АЭС мира привел к необходимости повышения ускорения безопасного останова в ряде АЭС. При проектировании АЭС недостаточно учитывать магнитуду и интенсивность предполагаемых землетрясений, для инженерных расчетов необходимо использовать конкретные параметры колебаний. Среди них важнейшее место занимает ускорение грунта, по которому можно с максимальной уверенностью судить о потенциальных нагрузках на сооружения и оборудование в зоне землетрясения. Приведена модернизированная система сейсмической защиты (ССЗ1М) энергоблоков отличающаяся надёжностью, отсутствием ложных срабатываний, стабильностью параметров во времени, защитой от внешних несанкционированных воздействий. The state and prospects of the development of nuclear energy in connection with seismic and other natural and technological hazards are considered in the article. The experience of operating nuclear power plants, statistics on accidents at nuclear power plants, and their causes are analyzed. Due to accidents at several nuclear power plants and a global change in energy policy priorities towards renewable energy sources (wind, solar, geysers, etc.), many of the technically developed countries (USA, Japan, Germany) declare a reduction in the role of nuclear energy in their energy plans. The threat of danger unites the efforts of countries such as the USA, France, Russia, Japan, South Korea, Canada and China in cooperation in the field of improving technologies, enhancing nuclear safety and developing nuclear infrastructure in newcomer countries. The most dangerous nuclear plants are located in Asia, where the increased seismicity is noted. As a result of the efforts to improve the safety of nuclear power plants, it is concluded that seismic hazard is reduced due to the deep automation and transfer of the main control functions of the nuclear power plant to the software package, improvement of decisionmaking algorithms in the event of an earthquake and other emergencies. One of the main goals of defense in depth is to block the dangers of human error and the combination of equipment failures and the errors of operators and managers. Safety systems should turn on automatically and block the actions of the NPP operator for a while. Sealed shells (containers) and placement of containers with a large amount of boron solution over the reactor, which is poured onto the reactor in the event of an accident and neutralizes radioactivity in case of its occurrence, are an effective protection for power units built in recent decades. A more detailed analysis of the seismotectonic situation of the sites of existing nuclear power plants in the world has led to the need to increase the acceleration of safe shutdown in several nuclear power plants. When designing a nuclear power plant, it is not enough to take into account the magnitude and intensity of the alleged earthquakes for engineering calculations, it is necessary to use specific vibration parameters. Among them, acceleration of the soil occupies the most important place, by which it is possible to judge with maximum confidence the potential loads on structures and equipment in the earthquake zone. The modernized seismic protection system (SSZ1M) of power units is characterized by reliability, the absence of false alarms, the stability of parameters in time, and protection against external unauthorized influences.


Vestnik MEI ◽  
2020 ◽  
Vol 6 (6) ◽  
pp. 11-17
Author(s):  
Dmitriy A. Kuz'min ◽  
◽  
Aleksandr Yu. Kuz'michevskiy ◽  
Artem E. Gusarov ◽  
◽  
...  

The reliability of nuclear power plants (NPPs) has an influence on power generation safety and stability. The reliability of NPP equipment and pipelines (E&P), and the frequency of in-service inspections are directly linked with damage mechanisms and their development rates. Flow accelerated corrosion (FAC) is one of significant factors causing damages to E&P because these components experience the influence of high pressure, temperature, and high flow velocity of the inner medium. The majority of feed and steam path components made of pearlitic steels are prone to this kind of wear. The tube elements used in the coils of high pressure heaters (HPH) operating in the secondary coolant circuit of nuclear power plants equipped with a VVER-1000 reactor plant were taken as the subject of the study. The time dependences of changes in the wall thickness in HPH tube elements are studied proceeding from an analysis of statistical data of in-service nondestructive tests. A method for determining the initial state of the E&P metal wall thickness before the commencement of operation is proposed. The article presents a procedure for predicting the distribution of examined objects' wall thicknesses at different times of operation with determining the occurrence probability of damages caused by flow accelerated corrosion to calculate the time of safe operation until reaching a critical state. A function that determines the boundary of permissible values of the HPH wall thickness distributions is obtained, and it is shown that the intervals of in-service inspections can be increased from 6 years (the actual frequency of inspections) to 9 years, and the next in-service inspection is recommended to be carried out after 7.5 years of operation. A method for determining the existence of FAC-induced local thinning in the examined object has been developed. The developed approaches and obtained study results can be adapted for any pipelines prone to wall thinning to determine the frequency of in-service inspections (including an express analysis based on the results of a single nondestructive in-service test), the safe operation time, and quantitative assessment of the critical value reaching probability.


Author(s):  
Chang Hyun Baek ◽  
◽  
Kyung Bae Jang ◽  
Tae Ho Woo

The artificial intelligence (AI) is applied to the safety analysis in the South Korean nuclear power plants (NPPs). The reinforcement learning (RL) is one of promising skills in the wise manipulations for the nuclear safety analysis where the reward is a critical factor to make the modelling. In the simulations, Y-axis means the relative value which shows the quantity of the accident possibility. The highest value is 4.0 in 46.25th year in which the values are increasing gradually. Otherwise, the values in the case with Agent gradually decrease. The highest value is near initial stage, which means the operation in NPPs is comparatively unstable. In the result, the values in the AI based controller graphs are higher than those of the other one. The RL algorithm is expressed by the Agent in this modelling, which is the most important factor in the AI-based operation in NPPs.


2020 ◽  
Vol 18 ◽  
pp. 10-22
Author(s):  
Y. M. Niearonov ◽  
◽  
T. Y. Baybuzenko ◽  
V. Y. Shenderovych ◽  
M. I. Vlasenko ◽  
...  

An algorithm of selecting the reactor technology type were constructed. The algorithm is based on a comparative assessment of the respective nuclear power plants. The formation of qualitative and quantitative criteria is performed for the estimation algorithm. Tools of the International Atomic Energy Agency (IAEA) INPRO-KIND project on multi-criteria comparative assessment of nuclear power plants for ranking the obtained results were adapted. The sensitivity analysis of the obtained results to change of numerical values and weight of criteria is carried out. The choice of the type of reactor technology for construction in Ukraine after 2035 is substantiated. It is shown that PWR and SMR reactor technologies in Ukraine are the most promising direction in the development of nuclear energy in Ukraine. Taking into account the factors of uncertainty and sensitivity to the values of the original data and possible risks, results of the analysis shows that there is a trend of advantages of SMR reactors, which generally have higher ratings compared to PWR, BWR and HWR. At the same time, the level of multi-criteria ratings of PWR reactors is close to SMR reactors. Making a further decision on the type of reactor technology for the conditions of Ukraine, it is necessary to take into account the possibility of its maximal total installed capacity deployment. It is necessary to conduct a separate study to determine the optimal ratio of reactor technologies PWR and SMR in the power system of Ukraine, taking into account the prospects for the deployment of renewable energy sources.


Author(s):  
Ye Cheng ◽  
Wang Minglu ◽  
Qiu Zhongming ◽  
Wang Yong

Nuclear power plants are used extensively as base load sources of electricity. This is the most economical and technically simple mode of operation. In this mode, power changes are limited to frequency regulation for grid stability purposes and shutdowns for safety purposes. However for countries with high nuclear shares or desiring to significantly increase renewable energy sources, the question arises as to the ability of nuclear power plants to follow load on a regular basis, including daily variations of the power demand. This paper give a detailed analysis of the technical and economic aspects of load-following with nuclear power plants, and summaries the impact of load-following on the operational mode.


2021 ◽  
pp. 182-182
Author(s):  
Vojin Grkovic ◽  
Djordjije Doder

In the paper are presented and discussed the results of a more complex research of technology portfolio competitiveness in power systems with high penetration of i-RES. Possible technology portfolios compositions are analyzed. The portfolios comprise very high participation of i-RES, as well as a certain participation of energy storage technologies, but also and other energy technologies like nuclear and fossil fueled power plants. Within the research are developed new competitiveness indicators i.e., dispatchability indicator and the technology portfolio?s assured capacity. The latter is defined on the basis of recently published Ulrich?s and Schiffer?s paper. Obtained results point out that inclusion of pumped-hydro storage plants improves portfolio?s dispatchability. However, within the researched interval up to PHS installed capacities relative to i-RES capacities of 0,3; numerical values of the dispatchability indicators are still below their values for the portfolio without i-RES. Increased participation of nuclear power plants contribute to the improvement of numerical values of the dispatchability indicators. The sensitivity analysis for the case of two times smaller cost of pumped hydro storage capacities is also performed. Hypothetical change of power system?s technology structure in sense of substitution hard coal and lignite fired power plants with wind generators or with nuclear power plants is also analyzed. The analysis points out that the substitution with nuclear power plants enables much better results regarding power system?s ability to change the power on demand than substitution with wind generators, particularly in the countries with high participation of hard coal and/or lignite in electricity generation.


Author(s):  
Hai Xie ◽  
Xuejiao Shao ◽  
Han Liu

Abstract Fatigue is identified as a significant degradation mode that affects nuclear power plants world-wide. Several international codes and standards (ASME, RCC-M, JSME, etc...) offer rules to predict its damaging effect on the locations of the various components of an NPP. These rules, which ensure conservatism and safe operation, have grown in complexity over the years because they have integrated R&D results showing aggravating effects that were not included in the original analyses (such as Environmental Assisted Fatigue[1][2]) but also because an economically viable design of components has required optimization and refinement of mechanical assessment methods. CNNC/NPIC has been following carefully the recent evolutions in the fatigue rules and has today finalized an in-house software enabling the evaluation of fatigue per ASME and RCC-M rules, with integration of environmental effects. On the other hand, EDF has been developing since 1989 its own in-house FEA code baptizedCode_Aster that is included in the Salome-Meca mechanical package. Salome-Meca is open-access and can be used freely by international users. Within Code_Aster, the fatigue postprocessor offers a span of criteria (Dang Van, Stress Intensity, etc...) to pick and choose from and even offers the possibility to make up owns one fatigue criteria. It also offers the possibility to post-process fatigue according to the RCC-M rules (POST_RCCM operator). It has been recently updated to perform industrial calculations integrating environmental fatigue[2][3]. Both entities have come to agree that validating a fatigue computer code is not an easy task. On the one hand, the full validation using hand calculations would be a highly tedious effort, given the technicality and the multiple choices to make along the various steps of the fatigue analysis. On the other hand, there are no experiments today which enable to directly lead a benchmark calculation to validate fatigue numerical results. In consequence, an accepted way of validating a code is to perform a benchmark analysis against another industrial fatigue code. CNNC/NPIC and EDF R&D China have therefore launched an effort to benchmark their respective codes, with the final objective of progressing together towards safe structural assessment practical methods for their power plants components.


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