Large-scale Nuclear Power Plants Research Articles

LARCalc, a tool to estimate sex- and age-specific lifetime attributable risk in populations after nuclear power plant fallout

A tool called LARCalc, for calculating the radiological consequences of accidental large scale nuclear power plant releases based on estimates of 137Cs ground deposition, is presented. LARCalc is based on a previously developed models that has been further developed and packaged into an easy-to-use decision support tool for training of decision makers. The software visualises the radiological impact of accidental nuclear power plant releases and the effects of various protective measures. It is thus intended as a rapid alternative for planning protective measures in emergency preparedness management. The tool predicts projected cumulative effective dose, projected lifetime attributable cancer risk, and residual dose for some default accidental release scenarios. Furthermore, it can predict the residual dose and avertable cumulative lifetime attributable risk (LAR) resulting from various protective measures such as evacuation and decontamination. It can also be used to predict the avertable collective dose and the increase in cancer incidence within the specified population. This study presents the theoretical models and updates to the previous models, and examples of different nuclear fallout scenarios and subsequent protective actions to illustrate the potential use of LARCalc.

The Usage of Micro Modular Nuclear Reactors on Military Headquarters as a Prospective Solution to Achieve Energy Security and Improve National Defense

Recently, there has been a trend of developing Micro Modular Reactors in the Small Nuclear Reactor field that can produce up to 15 MW(e) of power. Micro Modular Reactor is the fourth-generation technology which is included in the sub-category of Small Modular Reactor or Small Modular Reactor. This reactor produces electricity and heat that is safe, clean and economical which is believed to be better than large-scale Nuclear Power Plants. Micro-reactors have several technological advantages in that they can be manufactured in a factory setting, transported and assembled more easily, and can be integrated with renewable micro-power grids. Through the literature study method, this research analyzes the prospect of using Micro Modular Reactor technology for military headquarters in order to support national defense. The results of the analysis of this study conclude that MMR technology is worth trying to be applied in Indonesia, especially for electricity generation in state institutions, but it is necessary to carry out a further feasibility analysis of the possibility of state losses as a form of the ideas put forward in this study.

Hydroxy-Functionalized Hypercrosslinked Polymers (HCPs) as Dual Phase Radioactive Iodine Scavengers: Synergy of Porosity and Functionality.

Large-scale nuclear power plant production of iodine radionuclides (129 I, 131 I) pose huge threat in the events of nuclear disaster. Effective removal of radioiodine from nuclear waste is one of the most critical challenge because of the drawbacks of state-of-the-art adsorbents such as high cost, low uptake capacity and non-recyclability. Herein, two hydroxy-functionalized (-OH) hypercrosslinked polymers (HCPs), namely HCP-91 and HCP-92, have been synthesized and employed towards capture of iodine. High chemical stability along with synergistic harmony of high porosity and functionality of these materials makes them suitable candidates for capture of iodine from both vapor phase and water medium. Moreover, both the HCPs showed superior iodine removal performance from water in terms of fast kinetics and high removal efficiency (2.9 g g-1 and 2.49 g g-1 for HCP-91 and HCP-92 respectively). The role of functionality (-OH groups) and porosity has been established with the help of HCP-91, HCP-92 and non-functionalized biphenyl HCP for the efficient capture of I3 - ions from water. In addition, both HCPs exhibited excellent selectivity and recyclability towards triiodide ions, rendering the potential of these materials towards real-time applications. Lastly, Density functional theoretical studies revealed key insights and corroborate well with the experimental findings.

Erratum to: A New Algorithm for a Condenser Design for Large-Scale Nuclear Power Plants in Tropical Region

Erratum to: A New Algorithm for a Condenser Design for Large-Scale Nuclear Power Plants in Tropical Region

Benefit and risk evaluation of inland nuclear generation investment in Kazakhstan combined with an analytical MGT method

Purpose In the process of building the “Belt and Road” and “Bright Road” community of interests between China and Kazakhstan, this paper proposes the construction of an inland nuclear power plant in Kazakhstan. Considering the uncertainty of investment in nuclear power generation, the authors propose the MGT (Monte-Carlo and Gaussian Radial Basis with Tensor factorization) utility evaluation model to evaluate the risk of investment in nuclear power in Kazakhstan and provide a relevant reference for decision making on inland nuclear investment in Kazakhstan. Design/methodology/approach Based on real options portfolio combined with a weighted utility function, this study takes into account the uncertainties associated with nuclear power investments through a minimum variance Monte Carlo approach, proposes a noise-enhancing process combined with geometric Brownian motion in solving complex conditions, and incorporates a measure of investment flexibility and strategic value in the investment, and then uses a deep noise reduction encoder to learn the initial values for potential features of cost and investment effectiveness. A Gaussian radial basis function used to construct a weighted utility function for each uncertainty, generate a minimization of the objective function for the tensor decomposition, and then optimize the objective loss function for the tensor decomposition, find the corresponding weights, and perform noise reduction to generalize the nonlinear problem to evaluate the effectiveness of nuclear power investment. Finally, the two dimensions of cost and risk (estimation of investment value and measurement of investment risk) are applied and simulated through actual data in Kazakhstan. Findings The authors assess the core indicators of Kazakhstan's nuclear power plants throughout their construction and operating cycles, based on data relating to a cluster of nuclear power plants of 10 different technologies. The authors compared it with several popular methods for evaluating the benefits of nuclear power generation and conducted subsequent sensitivity analyses of key indicators. Experimental results on the dataset show that the MGT method outperforms the other four methods and that changes in nuclear investment returns are more sensitive to changes in costs while operating cash flows from nuclear power are certainly an effective way to drive investment reform in inland nuclear power generation in Kazakhstan at current levels of investment costs. Research limitations/implications Future research could consider exploring other excellent methods to improve the accuracy of the investment prediction further using sparseness and noise interference. Also consider collecting some expert advice and providing more appropriate specific suggestions, which will facilitate the application in practice. Practical implications The Novel Coronavirus epidemic has plunged the global economy into a deep recession, the tension between China and the US has made the energy cooperation road unusually tortuous, Kazakhstan in Central Asia has natural geographical and resource advantages, so China–Kazakhstan energy cooperation as a new era of opportunity, providing a strong guarantee for China's political and economic stability. The basic idea of building large-scale nuclear power plants in Balkhash and Aktau is put forward, considering the development strategy of building Kazakhstan into a regional international energy base. This work will be a good inspiration for the investment of nuclear generation. Originality/value This study solves the problem of increasing noise by combining Monte Carlo simulation with geometric Brownian motion under complex conditions, adds the measure of investment flexibility and strategic value, constructs the utility function of noise reduction weight based on Gaussian radial basis function and extends the nonlinear problem to the evaluation of nuclear power investment benefit.

SELECTION OF LARGE-SCALE NUCLEAR POWER PLANT BASED ON ECONOMIC AND RELIABILITY ASPECTS IN INDONESIAN POWER SYSTEM

Choosing the Indonesia's power systems that are suitable with the large-scale nuclear power plant (NPP) and the NPP's vendor country are crucial problems faced by Indonesian government. Therefore, this research analyzes the NPP impact on the power system reliability to choose the suitable power systems and the NPP economics of each possible vendor country to choose the optimal vendor that provides minimize cost. This research uses two electricity price scenarios: electricity production cost (scenario 1) and adjustment tariff (scenario 2). The results show that only Sumatra and Java-Bali system can be connected with the NPP. For both of these systems, Japanese NPP is not economical to be developed because it provides a levelized unit electricity cost (LUEC) of 0.116 USD/kWh, which is higher than the electricity prices. Meanwhile, Chinese and South Korean NPP is economical to be developed in both systems. For the Java-Bali system, Chinese NPP is the best choice in scenario 1 with a LUEC of 0.036 USD/kWh. In scenario 2, South Korean NPP that has a LUEC of 0.058 USD/kWh becomes the best choice because it has better public perception than Chinese. For the Sumatra system, South Korean NPP is the best choice in both scenarios.Keywords: Large-scale NPP selection, Indonesia power system, Reliability, Minimize cost, Electricity priceJEL Classifications: D21, D22, E39DOI: https://doi.org/10.32479/ijeep.11107

Increasing burn-up of KLT-40S fuel by introduction of neptunium

A floating nuclear power plant (FNPP) is one of the varieties of small nuclear power plants. Among mobile small nuclear power plants, floating power units with KLT-40S reactors, developed on the basis of reactor technologies already mastered in nuclear shipbuilding, deserve special attention. The involvement of protactinium and neptunium in the fuel compositions can significantly increase fuel burn-up in light-water reactor. The chains of nuclide transformations, starting with protactinium and neptunium, are characterized by a gradual improvement of the multiplying properties, which ensures an increased fuel burn-up. Due to limited reserves of protactinium and neptunium, their use in large-scale nuclear power plants may not proper. In this paper, the use of neptunium (as a more accessible material compared to protactinium) as burnable absorber in order to increase burn-up of KLT-40S fuel is considered. For neutron-physics calculations, GETERA and SKETCH-N software packages are used. Particular attention is paid to ensuring favourable values of fuel and coolant temperature reactivity coefficients.

Averting cumulative lifetime attributable risk (LAR) of cancer by decontamination of residential areas affected by a large-scale nuclear power plant fallout: time aspects of radiological benefits for newborns and adults

The averted cumulative lifetime attributable risk (LAR), the residual dose and highest ground deposition of 137Cs complying with a reference dose level of 20 mSv yr−1 to an individual returning after one year to an area contaminated by unfiltered releases of fission products from a nuclear power plant (NPP) were evaluated by applying an existing exposure model designed to compute age- and gender-dependent time-integrated LAR. The model was applied to four types of nuclear fallout scenarios, partly based on data from the Chernobyl and Fukushima releases and from theoretical source terms from Swedish NPPs. For rapid decontamination measures that achieve a 50% relative reduction in external dose rate within 1 year, compliance with the reference level 20 mSv yr−1 can be attained for an initial 137Cs ground deposition of up to 2 MBq m−2 with relaxed food restrictions. This compliance can be attained at even higher ground deposition (up to 4.5 MBq m−2) if using the strict food restrictions employed in Japan after 2011. Considering longer than 1 year return times it was also found that the benefit of implementing decontamination decreases rapidly with time (2–3 years half-time), especially if the fallout has a high initial 134Cs to 137Cs activity ratio and if the ecological half-time of the external dose rate is short (<5 years). Depending on fallout scenario the averted cumulative LAR for newborn girls by decontamination that is achieved after 5 years is only between 6% and 11% of that obtained by evacuation alone during the same time, indicating a rather limited radiological benefit of decontamination if delayed more than a few years. We conclude that decision makers and emergency response planners need to consider that protracted decontamination measures may have limited radiological benefit compared with evacuation in terms of averted future cancer cases, albeit it may have other societal benefits.

"Living in Contaminated Areas"-Consideration of Different Perspectives.

Following large-scale nuclear power plant accidents such as those that occurred at Chernobyl (Ukraine) in 1986 and Fukushima Daiichi (Japan) in 2011, large populations are living in areas containing residual amounts of radioactivity. As a key session of the ConRad conference, experts were invited from different disciplines to provide state-of-the-art information on the topic of "living in contaminated areas." These experts provided their different perspectives on a range of topics including radiation protection principles and dose criteria, environmental measurements and dose estimation, maintaining decent living and working conditions, evidence of health risks, and social impact and risk communication. A short summary of these different perspectives is provided in this paper.

A New Algorithm for a Condenser Design for Large-Scale Nuclear Power Plants in Tropical Region

A New Algorithm for a Condenser Design for Large-Scale Nuclear Power Plants in Tropical Region

Introduction of a method to calculate cumulative age- and gender-specific lifetime attributable risk (LAR) of cancer in populations after a large-scale nuclear power plant accident.

The effect of age and gender in risk estimates related to long-term residence in areas contaminated by nuclear power plant fallout was evaluated by applying the lifetime attributable risk (LAR) concept to an existing exposure model that was previously used for cumulative effective dose estimates. In this study, we investigated the influence of age distribution on the number of cancer cases by applying five different age distributions from nuclear power–producing countries (India, Japan, South Korea, and the United States), and Egypt because of intentions to develop nuclear power. The model was also used to estimate the effective dose and gender-specific LAR as a function of time after fallout for the offspring of the population living in 137Cs fallout areas. The principal findings of this study are that the LAR of cancer incidence (excluding non-fatal skin cancers) over 70 y is about 4.5 times higher for newborn females (5.4% per MBq m-2 of initial 137Cs ground deposition) than the corresponding values for 30 y old women (1.2% per MBq m-2 137Cs deposition). The cumulative LAR for newborn males is more than 3 times higher (3.2% versus 1.0% per MBq m-2 137Cs deposition). The model predicts a generally higher LAR for women until 50 y of age, after which the gender difference converges. Furthermore, the detriment for newborns in the fallout areas initially decreases rapidly (about threefold during the first decade) and then decreases gradually with an approximate half-time of 10–12 y after the first decade. The age distribution of the exposed cohort has a decisive impact on the average risk estimates, and in our model, these are up to about 65% higher in countries with high birth rates compared to low birth rates. This trend implies larger average lifetime attributable risks in countries with a highly proportional younger population. In conclusion, the large dispersion (up to a factor of 4 between newborns and 30 y olds) in the lifetime detriment per unit ground deposition of 137Cs over gender and age in connection with accidental nuclear releases justifies the effort in developing risk models that account for the higher radiation sensitivity in younger populations.

Sektor konwencjonalnej elektroenergetyki wobec wyzwania transformacji technologicznej

The article criticises the direction in which the Polish electrical power sector is to develop, as stated in the draft energy policy. Such a draft policy assumes not only that overwhelming dependence on hard and brown coal for electricity generation should be maintained in the long term, but also that large-scale nuclear power plants should be developed. The starting point of the article is a statement that the authors of this policy do not sufficiently take into account the challenges of, and related threats to, both types of energy generation resulting from progress in technology transformation involving the rapid development of renewable energy. The purpose of the article is to present arguments confirming the following twofold thesis. Firstly, the greatest threat to coal and nuclear power plants is the so-called death spiral, which results in those assets gaining a stranded status. Secondly, against the backdrop of the growing share of renewable energy sources in the national energy mix, there is a need to focus on the development of gas sources for electricity production. The justification of this thesis is based on an analysis of the current levels of knowledge about the progress and direction of the power sector technological transformation, especially in solar and wind electricity generation, electricity storage as well as smart grids and meters. The problem of spiral death as an existential threat for the economics of coal and nuclear power is then analysed, and against this background the advantages of gas source development are presented.

Variable Reactivity Control in Small Modular High Temperature Reactors Using Moderation Manipulation Techniques

With extensive research being undertaken into small modular reactor design concepts, this has brought new challenges to the industry. One key challenge is to be able to compete with large scale nuclear power plants economically. In this article, a novel approach is applied to reduce the overall dependence on fixed burnable poisons during high reactivity periods within a high temperature graphite moderated reactor. To reduce the excess activity, we aim to harden the flux spectrum across the core by removing part of the central moderation column, thus breeding more plutonium, in a later period the flux spectrum is softened again to utilise this plutonium again. This provides a neutron storage effect within the 238U and the resulting breeding of Plutonium. Due to the small size and the annular design of the high temperature reactor, the central reflector is key to the thermalization process. By removing a large proportion of the central reflector, the fuel within the proximity of the central reflector are less likely to receive neutrons within the thermal energy range. In addition to this, the fuel at the extremities of the core have a higher chance of fission due to the higher number of neutrons reaching them. This works as a method of balancing the power distribution between the central and outside fuel pins. During points of low reactivity, such as the end of the fuel cycle, the central reflector can be reinserted and the additionally bred plutonium and U235 at the centre of the core will encounter a higher probability of fission due to more thermal neutrons within this region. By removing the central reflector, this provided a 320 pcm reactivity drop for the duration of the fuel cycle. The plutonium buildup provided additional fissile material up until the central reflector was reinserted. The described method created a two-fold benefit. The overall full power days within the core was increased by ~31 days due to the additional fissile material within the core and secondly the highest loaded power pins saw a 30% power reduction during the removal of the central reflector column.

Alternative Fueling Scheme for the Indonesian Experimental Power Reactor (10 MWth Pebble-Bed HTGR)

The National Nuclear Energy Agency of Indonesia (BATAN) is launching a plan (2014) to build an 10 MWth Experimental Power Reactor (Reaktor Daya Eksperimental, RDE) in the Agency’s largest Research Center site, i.e. the Puspiptek Complex, Serpong, South Tangerang, Banten, as a first strategic milestone for the introduction of large scale nuclear power plant fleets into the country. The main objective of the plan is to demonstrate safe and reliable electricity and process heat generation from a nuclear reactor. The RDE is a very small sized pebble-bed high temperature gas-cooled reactor (HTGR) with low enriched uranium (LEU) UO2 TRISO fuel. Following our previous design study with multipass fueling scheme, a scoping study on fuel composition parameters, namely heavy metal (HM) loading per pebble and uranium enrichment was conducted for the simpler once-through-then-out (OTTO) fueling scheme. No need of burnup measurement devices and refueling mechanism to send back discharged fuel pebbles into the core, low power and power density, and simple operation of the RDE become strongest motivation for the present work. The objective function for the optimization is the fissile loading requirement per energy generated (kg/GWd). The optimal heavy metal loading was found around 8 g/pebble while the uranium enrichment corresponding to the 80 GWd/t discharge burnup constraint is approximately 13.7 w/o. Compared with the burnup calculations results of multipass fueling scheme, OTTO fueling scheme burnup performance is slightly inferior in that slightly higher enrichment and fissile loading per pebble are required to achieved the same average discharge burnup.

Safety constraints and optimal operation of large‐scale nuclear power plant participating in peak load regulation of power system

Comprehensively considering the operation cost and safety constraints of nuclear power, an optimal operation scheme of large-scale nuclear power plant participating in peak load regulation of power system is proposed. After quantitatively analysing the peak load regulation cost of nuclear power, the optimal objective is set to minimise the total operation cost including the fuel cost, the start-stop cost, and the peak load regulation cost. On the basis of the normal constraints of power scheduling, safety constraints of the nuclear power unit's daily output performance and power characteristic constraints of the pumped storage unit are considered. The mixed integer programming method is used to achieve the solution of the optimal operation scheme. Simulation results from a regional power system show that the proposed optimal operation scheme can effectively reflect the real characteristic of nuclear power and apply to power dispatching analysis under the background of the large-scale access of nuclear power. In comparison to other two typical schemes of peak load regulation, the proposed optimal operation scheme of peak load regulation is more economic and efficient.

Economy, safety and applicability of small modular reactors

Small modular reactors are a new generation of low-energy-output, low-hazard, compact and modular nuclear reactors, with an output of &lt;300 MWe per unit. With the integration of inherent and passive safety measures, off-site construction and higher fuel burn-up rates, they promise a safer, lower-waste and reduced-risk venture, with earlier investment returns for investors compared with large-scale nuclear power plants. Moreover, non-proliferation is enhanced through the use of small quantities of non-weapons-grade nuclear fuel or the introduction of alternative potential fuels, such as thorium or fuel waste and actinides. This paper reviews the state of the art and discusses the economic feasibility of small modular reactors, with a focus on levelised cost of electricity, economy of scale and limitations for a country wishing to embark on nuclear energy through their deployment. Concerns regarding the integration of small modular reactors into the existing electrical grids of countries with various or no levels of nuclear-power production capability are also discussed. Suggestions on alternatively calculating the cost of small modular reactors and the legislation route are also provided, along with the pros and cons of the economics and safety of small modular reactor deployment in a country new to nuclear power.

Module Coordination Control of MHTGR-Based Multi-Modular Nuclear Plants

Based on the multi-modular scheme, modular high temperature gas-cooled reactor (MHTGR) can be used to build large-scale nuclear power plants with inherent safety feature at any desired power ratings. It is so clear that module coordinated control is very crucial for the safe and stable operation of multi-modular MHTGR plants, which induces the importance of the study in module coordination. Motivated by this, it is revealed in this paper that coordinated control of multiple MHTGR-based NSSS modules is essentially the flowrate-pressure regulation of a fluid flow network (FFN). A novel pressure-flowrate control with the proportional-integral (PI) form is then proposed for the FFN that couples <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$N$ </tex-math></inline-formula> MHTGR-based NSSS modules. This control provides the input-to-state stability (ISS) of the closed-loop system. Numerical simulation results not only verify the theoretic results but also show the satisfactory control performance.

Hardness Prediction for Temper Bead Welding of Non-Consistent Layer Technique

Temper bead welding (TBW) is one effective repair welding method for the large-scale nuclear power plants. Consistent Layer (CSL) technique is the theoretically most authoritative method among the five temper bead welding techniques. However in the actual operation, CSL technique is difficult to perform, and non-CSL techniques (Controlled Deposition technique, Half Bead technique, et al) are mainly used in the actual repair process. The thermal cycles in heat affect zone (HAZ) of non-CSL technique are more complicated than that of CSL techniques. Through simplifying the complicated thermal cycles to 4 types of thermal cycles, the neural network-based hardness prediction system for non-CSL techniques has been constructed. The hardness distribution in HAZ of non-CSL techniques was calculated based on the thermal cycles numerically obtained by finite element method (FEM). The predicted hardness was in good accordance with the experimental results. It follows that the thermal cycle simplification methods are effective for estimating the tempering effect during temper bead welding of non-CSL techniques.

Using the Environmental History of the Commonwealth to Enhance Pennsylvania and U.S. History Courses

Why teach Pennsylvania environmental history? How can teachers use it to improve students' understanding of the history of the state, the region, and the nation? I have found through my teaching at West Chester University that environmental history grounds American history in the physical realities upon which human history unfolds: the natural resource bases, both renewable and nonrenewable, that all societies use to construct their economies, cultures, and political systems. Recognizing this grounding, students can better understand the complex world in which they live, and thus better respond to the challenges they will face as citizens and consumers.

Simulation of Multi-dimensional Heterogeneous and Intermittent Two-Phase Flow by Using an Extended Two-Fluid Model

A new gas-liquid two-phase flow simulation method has been developed based on the extended two-fluid model, which has capabilities of both the two-fluid and the interface-tracking models. The VOF (Volume of Fluid) technique has been introduced for suitable interface calculations. Interfaces of free surface and large bubbles are calculated directly by solving transport of a steep void fraction gradient corresponding to interface, while averaged behavior of microscopic dispersed bubbles and droplets are calculated in the two-fluid model scheme. It is expected that the present method can treat effects of significant kinetic interaction between the phases directly without empirical correlations. The calculated propagation of wet front in a dam break problem is close to experimental data. The predicted flow patterns of complex gas-liquid two-phase flow in a flat tube are quite similar to observations with a video camera. The present simulation will be a useful tool for predictions of integral behavior of thermal-hydraulic phenomena in large-scale nuclear power plants.