Pessimistic Conditions Research Articles

Robust day-ahead scheduling of cooperative energy communities considering multiple aggregators

Future cities must play a vital role in reducing energy consumption and decarbonizing the electricity sector, thus evolving from passive structures towards more efficient smart cities. This transition can be facilitated by energy communities. This emerging paradigm consists of collectivizing a set of residential installations equipped with onsite renewable generators and storage assets (i.e., prosumers), which can eventually share resources to pursue collective welfare. This paper focuses on cooperative communities, where prosumers share resources without seeking selfish monetary counterparts. Despite their apparent advantages, energy management and scheduling of energy communities suppose a challenge for conventional tools due to the high level of uncertainty (especially due to intermittent renewable generation and random demand), and privacy concerns among prosumers. This paper addresses these issues. Specifically, a novel management structure based on multiple aggregators is proposed. This paradigm preserves users' confidential features while allowing them to extract the full potential of their assets. To efficiently manage the variety of assets available under uncertainty, an adaptive robust day-ahead scheduling model is developed, which casts as a solvable and portable Mixed Integer Linear Programming framework, which eases its implementation in real-world cases. The new proposal concerns uncertain generation and demand using a polyhedral representation of the uncertainty set. A case study is conducted to validate the developed model, showing promising results. Moreover, different results are obtained and analysed. Finally, it is worth remarking on how the level of robustness impacts the collective bill, incrementing it by 75 % when risk-averse conditions are assumed. In addition, the role of storage assets under pessimistic conditions is remarked, pointing out that these assets rule the scheduling plan of the community instead of renewable generators.

Optimizing municipal solid waste management in industrial ports: A case study of source separation implementation

ABSTRACT With the acceleration of industrialization and population growth, there has been a notable surge in municipal solid waste (MSW) production globally. This necessitates the development of efficient waste management strategies that align with sustainable economic, environmental, and social goals. Implementing sorting and source separation policies serves as foundational steps toward optimizing material flow and resource utilization. In industrial areas, waste generation around a primary source may improve policy implementation and participation. Given the unique strategic context of port environments, Bahregan Port in Iran was selected as a case study to evaluate the proposed methodology. Three integrated scenarios were formulated and prioritized using the ELECTRE-I model: currently practiced collection method, and segregated collection followed by source separation of MSW into two or three groups. The analysis identified the third scenario as the most effective approach. Remarkably, when evaluating the results under optimistic and pessimistic conditions, the ranking of preferences remained consistent across scenarios in the optimal state. Under pessimistic conditions, all scenarios received identical scores, indicating significant uncertainty in criteria weights. Furthermore, sensitivity analysis revealed that criteria such as the raw material sources protection, emissions in the waste separation sector, and greenhouse gas emissions were highly influential. Interestingly, criteria with the highest weighting did not always dictate the final scenario selection. External factors, such as expert opinions on specific criteria, played a pivotal role in scenario prioritization. This research serves as a foundational study for source separation initiatives, offering practical and technically viable strategies to enhance environmental sustainability within industrial settings. Implications Statement Rising industrialization and population growth have led to increased municipal solid waste (MSW) production worldwide. To address this, efficient waste management strategies are essential, focusing on sustainability and resource optimization through sorting and source separation policies. By prioritizing the scenario of segregated collection followed by source separation – industrial areas can optimize material flow and resource utilization. The study highlights the influence of criteria like raw material protection, emissions, and greenhouse gases, making this research foundational for enhancing environmental sustainability in industrial settings. This study provides practical strategies for enhancing environmental sustainability in industrial settings through source separation initiatives.

Financial Feasibility of A Hair Care-Based Business

Hair loss, or alopecia, is a global concern, with 3.8% of Southeast Asia's population affected by Alopecia Areata, an autoimmune disorder. Traditional treatments like minoxidil and finasteride, while effective, often have side effects. To address this, Sassle, a haircare startup, developed an almond-based hair serum in collaboration with ITB's School of Pharmacy, offering a natural solution without adverse effects. Sassle has completed product development and is preparing to launch its go-to-market strategy. This study evaluates the financial feasibility of Sassle's product using primary data from Sassle's records and secondary data from industry comparables. Key financial metrics such as the Payback Period, Net Present Value (NPV), and Internal Rate of Return (IRR) were analyzed, along with a scenario analysis under pessimistic, base, and optimistic conditions. The base scenario indicated a payback period of 3 years and five months, a positive NPV of Rp381,007,156, and an IRR of 49%, surpassing the Weighted Average Cost of Capital (WACC) of 5.02%. In the pessimistic scenario, with a 25% sales reduction, the payback period was four years and 11 months, with a positive NPV of Rp265,828,152 and an IRR of 32%. With a 15% sales increase, the optimistic scenario predicted a 2-year, 1-month payback period, a positive NPV of Rp622,915,633, and an IRR of 67%. The findings confirm that Sassle's business model is financially viable and capable of substantial returns, providing critical insights for strategic decisions in investment, market expansion, and operational scaling.

Probabilistic assessment of existing shield tunnel longitudinal responses to tunnelling

AbstractThis paper proposes a probabilistic‐based framework to assess the failure probability of the existing shield tunnel owing to undercrossing tunnelling. A novel deterministic model using the two‐phase analysis method is presented to evaluate the longitudinal behaviours of the in‐service shield tunnel. First, the tunnelling‐induced settlement is estimated using the Loganathan and Poulos’ method; second, the longitudinal beam‐spring model (LBSM), which can explicitly consider the circumferential joints, is applied to reflect the performances of the existing shield tunnel. Two well‐documented case histories are selected to validate the effectiveness of the deterministic analysis model. The predictions are also compared with previous analytical methods. Afterward, to improve the computational efficiency, a surrogate model is then established to replace deterministic model and perform the global sensitivity analysis (GSA). A probabilistic analysis is further performed to explore the tunnelling‐induced deformation characteristics of the shield tunnel by means of Monte Carlo simulation (MCS) method. Parametric analyses are further performed to explore the influences of key variables on the failure probabilities of the existing shield tunnel. The results show the proposed deterministic model gives a satisfactory prediction in tunnelling‐induced responses of the existing shield tunnel. The LBSM can reflect the segmental ring and joint deformations more realistically. The uncertainties in the ground elastic modulus, joint rotation stiffness and the joint shearing stiffness dominate the tunnel settlement, joint opening and dislocation, respectively. The failure probability of tunnel settlement is more sensitive to volume loss than that of the joint opening and dislocation. The whole system failure probability is identical to that of the tunnel settlement failure mode. By increasing the coefficient of variation (COV) of random variables, probability density function (PDF) curves for neutral and pessimistic conditions become lower and wider, and the maximum joint opening and dislocation positions corresponding to the peaks of PDF apparently deviate from that of the determinate results. Increasing the two tunnel clearances, the allowable volume loss for opening and dislocation increase linearly, but it has insignificant influence on the tunnel failure mode. However, enlarge the new tunnel diameter leads to rapid decrease in the allowable volume loss for all failure modes.

Dry Port Financial Feasibility Analysis Model

The sea transportation system that is interconnected and provides value for loading and unloading services at the main port of Tanjung Priuk is already over capacity. The establishment of a dry port in Tangerang Regency is expected to facilitate the flow of export and import goods, streamline logistics costs, and solve the dwelling time problem that occurs. The plan to establish the Tangerang Dry Port requires an analysis of the financial feasibility of the investment. The method used to solve this problem is using the Internal Rate of Return (IRR), Net Present Value (NPV), and Payback Period. This feasibility analysis calculation was carried out during pre-construction and after construction so that these calculations can be used as reference material in every decision-making, especially those related to the finances of Tangerang Dry Port. The feasibility analysis calculation uses 3 (three) scenarios, namely for optimistic conditions the IRR value is 28.8%, for moderate conditions the IRR value is 13.6%, and for pessimistic conditions the IRR value is 7.2%. For optimistic conditions the NPV value is 1,716.7 billion, for moderate conditions the NPV value is 697 billion, for optimistic conditions the NPV value is 255 billion. For optimistic conditions the payback period is 6.87 years, for moderate conditions the payback period is 9.26 years, and for pessimistic conditions the payback period is 11.2 years. From the results above, optimistic, and moderate conditions are the most feasible scenarios for developing the Tangerang Dry Port.

Economic sustainability for developing a less polluting eucalyptus-charcoal productive system in emerging markets

Charcoal plays a relevant role in developing countries, with potential to contribute to the energy needs as a cheaper and carbon-friendly alternative. In Brazil, eucalyptus-charcoal has gained attention as an input for metal-steel industries, mostly supplied by small and medium forest producers. Those commonly use rudimentary charcoal-kilns, characterized by higher greenhouse gas (GHG) emissions, reduced productivity and economically unsustainable impacted by their reduced financial management. In order to fulfill this gap, a simplified financial planning model and an economic analysis of a less polluting charcoal productive system, called kilns-furnace system, were performed, also comparing to traditional charcoal-kilns. A differentiated cost of capital pricing model was also proposed, adjusted to bioenergy projects in emerging markets. Results showed that kilns-furnace system presented the best financial indicators, with greater free cash flow capacity, shorter reimbursement period, reduced charcoal production cost, better return on invested capital and a financial resilience even under pessimistic conditions. With its risk-return ratio verified, kilns-furnace larger insertion may be an attraction for charcoal producers, with probable increased long-term economic sustainability when compared to traditional kilns. The proposed cost of capital pricing model opened a new perspective for its calculation in developing countries, and should be used by producers, companies, and government in investment decision and as a guidance for financing lines.

WITHDRAWN: Does stock return affect decomposed energy shocks differently? Evidence from a time frequency quantile-based framework

We study the interconnections and consequences of fluctuations in energy prices on the returns of stocks within both highly optimistic and pessimistic market conditions, considering both short and extended timeframes. The research follows a two-part methodology: initially breaking down energy price shocks into components of demand, supply, and risk using the Ready method, and subsequently applying a quantile frequency connectedness technique. The outcomes demonstrate that the correlation between energy price shocks and stock returns in the enlarged BRICS markets is substantial during extremely bullish and bearish periods, but comparatively lower during normal circumstances. Among the various types of energy price shocks, those driven by shifts in demand exhibit a more pronounced influence on stock returns compared to supply and risk-induced shocks. The transmission of effects from energy price shocks to stock returns becomes evident over extended periods, i.e., beyond five days, particularly in the context of extreme bullish and bearish market conditions. Notably affected by these shocks, mainly in the long term, are the oil-exporting countries such as Russia, Brazil and the upcoming joiner Saudi Arabia (KSA), as well as China – an oil-importing nation. Given the economic and political significance of the inclusion of the heavyweight oil-exporting nations in BRICS is likely to make in minimising the gap between the global North and the South, these findings hold significant implications for both investors and policymakers, guiding them in making well-informed investment choices and crafting effective strategies for managing risks.

Analisis Kelayakan Ekonomi dan Finansial Pada Proyek Kawasan Pembangunan Perusahaan Siap Bangun (Studi Kasus: Perumahan Griya Sukasari Subang)

In the era of globalization, the increasing rate of population growth will affect the need for housing. This need becomes a problem if the continuous increase in demand can cause land prices to increase. It is known that investment in property is very promising and is increasingly in demand by the public both in the short and long term. In this research, the building of housing in Sukasari Village will be very strategic considering that this area is starting to develop an industrial area. To meet residential needs, the developer built 16 housing units on 1900 m2 of land at that location. The feasibility obtained from the 16 unit Housing Development Project was carried out in the form of an analysis to determine investment and financial feasibility based on the Net Present Value, Benefit Cost Ratio, Internal Rate of Return, Return on Investment, Return on Equity, Break Even Point and Payback Period. The profit obtained is with an NPV value of Rp. 1,284,651,362 (NPV > 0), BCR = 1.18 (BCR > 1), BEP in position 9 housing units sold, PP in the 10th month, IRR value = 118%, ROI and ROE have a level and ratio of 52%, moderate conditions make a profit with an NPV value of Rp. 85,000,830 (NPV > 0), BCR = 1.02 (BCR > 1), BEP in the position of 9 units sold, PP for 6 years, IRR value of 102%, ROI and ROE have a ratio of 6%. Meanwhile, in pessimistic conditions suffered a loss with an NPV value of Rp. 1,077,912,437, BCR 0.64 < 1, BEP does not have a break-even point, and the break-even time or PP occurs in the 13th year which can be interpreted as not breaking even, and the IRR value is 99%, ROI and ROE have a ratio level of 0.40%. It was concluded that the 16-unit housing development project could be profitable and feasible to implement, optimistic conditions with the construction process being completed and the housing units being sold in full in the 12th month.

Predicting Investment Feasibility in Perumda Establishment Using Payback Period, Net Present Value, and Internal Rate Return

This study examines the feasibility of investing in the establishment of a Regional Public Company in the field of rice distributors in the Yahukimo Regency, Papua. The investment feasibility analysis used consists of evaluating the payback period, Net Present Value, and Internal Rate Return. The analysis is also combined with various possible conditions, namely pessimistic, moderate and optimistic conditions. The type of data used is secondary data with a qualitative descriptive research approach. The results of the study show that the attitude of PERUMDA of Yahukimo district in the field of rice distribution is that the Payback Period, NPV, and IRR values show that they are feasible. The feasibility of investing in PERUMDA as a rice distributor is feasible in optimistic, moderate and pessimistic conditions. The establishment of the New PERUMDA will contribute to the absorption of rice production by the Yahukimo Regency community as a business process on the upstream side. Meanwhile, the business processes on the downstream side will have an impact on increasing PAD from the company's operating profit from the sale of rice

Novel propane dehydrogenation process design integrated with membrane reactor and solid oxide fuel cell: Economic and environmental aspects

As environmental pollution worsens, many strategies are emerging to reduce CO2 in various chemical processes. The practical strategy of byproduct hydrogen utilization in propane dehydrogenation is also being reviewed a lot. In this work, a comprehensive analysis was conducted for propane dehydrogenation process design integrated with membrane reactor and solid oxide fuel cell. Especially, membrane reactor and sequential reactor were used to increase the yield of the process. All assessments were investigated based on Aspen Plus®, which is commercial software for process simulation. Levelized cost of electricity was derived through itemized cost estimation. The 2.81 $ kWh-1 of levelized cost of electricity was revealed through itemized cost estimation; it is higher than industrial electricity in general. Therefore, various scenarios were conducted to reduce the levelized cost of electricity compared to industrial electricity price on sale, currently. The optimistic case (1.20 $ kWh-1) can be priced close to industrial electricity price through 100 % of propane recycling rate and − 20 % of reduction in the price of the influential factors. For life cycle assessment, the environmental impact of global warming potential was assessed as 4.93 kg CO2 eq MJ-1 of CO2 emissions. Various scenarios had been proposed to reduce CO2 as with the economic assessment. Under pessimistic, realistic, and optimistic conditions, the results of global warming potential were 5.61, 4.93, and 4.25 kg CO2 eq MJ-1, respectively. The comprehensive analysis will be presented as guidelines for the actual use of byproduct hydrogen.

Authenticity and Its Discontent as Reflected on Heinrich Böll’s The Laugher

People are justified to be original but it could hinder people from their freedom as stated by Jean-Paul Sartre. The Laugher is Heinrich Böll’s short story of someone whose job is to laugh in various platforms. His laughter must be heard as original but his own life is full of pessimistic conditions. Then, how may being authentic be contested through Böll’s The Laugher? Through qualitative method on cultural studies, this paper puts tensions between being authentic by Sartre and reality of Böll’s story. The laugh seems to be authentic, but it is set to trigger other laughter, yet he is not happy though he laughs every time. He is demanded to laugh, but the laugh is bad faith as supported by Sartre. Authenticity in Böll’s story shows its own discontent. In conclusion, the story shows how laughter is done in a timed set. His laugh is not freedom since his own life is full of sad conditions.

Blockchain-Based Architecture for a Sustainable Supply Chain in Cloud Architecture

Blockchain technology, as a well-known technology in financial spaces, has many advantages in non-financial industries and supply chains. Two of the main benefits of blockchain technology are smart contracts and distributed decision-making processes. These features can be especially useful in implementing Industry 4.0. Moreover, this technology can increase productivity in supply chains by enhancing transparency, reducing operational costs, and improving monitoring and supervision throughout the lifecycle of products. In this paper, we introduce a blockchain-based architecture for a supply chain in cloud architecture. This approach leads to the more efficient implementation of Industry 4.0 and increases sustainability in the supply chain. In this study, we aim to investigate whether the proposed blockchain-based platform affects sustainability in the supply chain. From a sustainability perspective, we solve the large-scale problem of a cloud-based production–distribution system in centralized and distributed states. The results of the solution indicate a significant improvement in the decentralized state compared to the centralized state and this improvement enhances sustainability in the supply chain. We verify the proposed model by considering an axiomatic design algorithm. In the distributed model, the system cost is reduced by up to 45%, and the solving time is decreased by approximately 51% in pessimistic conditions and by about 87% in optimistic conditions. These improvements directly enhance economic and environmental sustainability, resulting in reduced energy consumption.

Uncertainties-Based Potential Time and Cost Overrun Assessment While Planning a Hydropower Project

Uncertainties are predominant in hydropower development that lead to risks of time and cost overruns. The overruns’ assessment requires quantitative data that is difficult to obtain and sometimes partially or completely unavailable. Accordingly, this study proposes an expert fuzzy-based system for assessing the impact of uncertainties on time and cost overrun. A Bayesian network analysis is used wherein the experts’ opinions are incorporated through an analytic hierarchy process for the uncertainty’s likelihood and impact. A fuzzy inference system is used to incorporate the decision maker’s optimistic and pessimistic approaches. The proposed methodology is illustrated through a 3×42 MW run-of-river Myntdu Leshka Hydroelectric project in India. The project’s initial likely completion time was five years with a cost of ₹3,630 million at the 1999 price level. The results state that the project’s time and cost overruns lie between 158% and 196% and between 235% and 276%, respectively, under optimistic and pessimistic conditions. Such a methodology has not been applied by past studies for hydropower projects, which is the study’s main contribution. The methodology can be easily applied by construction project developers globally in different fields by varying the uncertainties, their likelihood, and impact scales as per different risk perceptions and regional conditions.

Hubungan Kausalitas antara Sentimen Investor dan Pasar Keuangan Indonesia

This study aims to see the causal relationship that occurs between investor sentiment-based google search and the Indonesian stock-bond market in 2020. The test used in this study is a combined test between the quantile test to see the effect of investor sentiment on optimistic (pessimistic) conditions and the Granger causality test to detect the causal relationship that occurs between variables. The results of the study found that there was a one-way relationship between investor sentiment and the Indonesian stock market where investor sentiment affects the stock market. Interestingly, in the bond market, causal relationship between variables can’t be found. This study also found that the causal relationship between investor sentiment variables and financial markets only occurs when the optimistic and pessimistic conditions of investors aren't in extreme conditions.

Impact of COVID‐19 pandemic on risk transmission between googling investor’s sentiment, the Chinese stock and bond markets

PurposeThe main objective of this paper is to investigate whether the investors' behavior under optimistic (pessimistic) conditions has an impact on risk transmission between the Chinese stock and bond markets and the sector indices mainly during the COVID-19 pandemic.Design/methodology/approachThis study uses a new measure of the investor's sentiment based on Google trend to construct a Chinese investor's sentiment index and a quantile causal approach to examine the causal relationship between googling investor's sentiment and the Chinese stock and bond markets as well as the sector indices. On the other hand, the network connectedness is used to estimate the spillover effect on the investor's sentiment and index returns. To check the robustness of the study results, the authors employed the Chinese VIX, as another measure of the investor's sentiment using daily data from May 2019 to December 2020.FindingsIn fact, the authors found a dual causality between the investor's sentiment and the financial market indices in optimistic or pessimistic situations, which indicates that positive and negative financial market returns may have an effect on the Chinese investor's sentiment. In addition, the results indicated that a pessimistic investor's sentiment has a negative impact on the banking, healthcare and utility sectors. In fact, the study results provide a significant peak of connectivity between the investor's sentiment, the stock market and the sector indices during the 2015–2016 and 2019–2020 turmoil periods that coincide respectively with the 2015 recession of the Chinese economy and the COVID-19 pandemic.Originality/valueThis finding suggests that the Chinese googling investor's sentiment is considered as a prominent channel of shock spillovers during the coronavirus crisis, which confirms the behavioral contagion. This study also identifies the contribution of a particular interest for portfolio managers and investors, which helps them to accordingly design their portfolio strategy.

Water resources sustainability under climate variability and population growth in Iran: A system dynamics approach

The change in availability of water resources has a dynamic behavior and is influenced by many factors such as population growth and climate variability over time. Understanding the impacts of such factors on water resources vulnerability is essential for ensuring the sustainability of future water resources. In this study, a water resources sustainable index is built using a system dynamics model to assess the effects of different scenarios at the Kowsar dam basin in southwestern Iran where managing water resources is serious challenging due to periodic drought. Based on the baseline scenario, the total population, as well as total water demand, will increase and water supply will decrease throughout the simulated period. Therefore, the imbalanced supply-demand of water can cause the water system vulnerable. In this regard, water management policies should concentrate on the demand side of water to address the problem of water resource shortage in a good manner. Although pessimistic climatic conditions along with population growth put the water system in the worse situation of water availability, where the demand control policies likely help meet the increasing water demand. Compared to the pessimistic conditions, the water sustainability index improves in normal and optimistic conditions. The highest sustainability index was obtained after controlling water demand in optimistic weather condition. Consequently, the government should provide a context in which people learn to control their daily water consumption. Also, it suggests that we can conserve water resources in the agricultural sector with conservation policies.

Simulating automakers’ response to zero emissions vehicle regulation

Little research explores automaker response to supply-focused regulation in the long-run, such as zero-emissions vehicle (ZEV) mandates. To that end, we develop and apply the AUtomaker-consumer Model (AUM), which simulates interactions between behaviorally-realistic consumers and a profit maximizing automaker from 2020 to 2030. AUM endogenously represents multi-year foresight for the automaker, including decisions about: (i) increasing ZEV model variety, (ii) intra-firm cross-price subsidies, and (iii) investing in R&D to reduce future ZEV costs. Under both optimistic and pessimistic conditions, automakers are simulated to fully or mostly comply with a 2030 requirement of 30% ZEV sales (rather than pay a penalty). Of the three compliance mechanisms, intra-firm cross-price subsidization dominates. The policy could reduce automaker profit by 7% to 44% in 2030 (relative to the baseline in the same year), mostly due to reduced vehicle sales in total, though overall profits still grow year-on-year from 2020. We identify key uncertainties in these results.

HadGEM2 Küresel İklim Modeli Tahminine Dayalı Konya Kapalı Havzası İçin Olası Tarımsal Kurak Dönemleri

Drought is one of the most dangerous natural disasters that can have serious impacts on the economy and environmental systems, especially on living life. When compared with other disasters, drought has many differences with respect to structure. In particular, agricultural droughts cause great costs as well as serious consequences. According to the IPCC report of 2014, Turkey will increase in the future temperature scenarios rainfall is expected to decrease the contrast. When this situation is taken into consideration, it is estimated that the duration and severity of drought disasters likely to be experienced throughout our country will increase. The determination of agricultural droughts that are likely to occur in the future affects not only sustainable agricultural production but also all other production areas. In this study, the monthly rainfall series estimated up to 2100 under the optimistic (RCP 4.5) and pessimistic (RCP 8.5) conditions of the Representative Concentration Pathway (RCP) in the HADGEM2 global climate model for Konya Closed Basin were used. The obtained monthly rainfall series were analysis with Standardized Precipitation Index (SPI). As a result of the analysis of SPI, it was detected 4 agricultural drought periods (2043-2044, 2046-2047, 2086-2087 and 2090-2091) for RCP 4.5 scenario. According to RCP 8.5 scenario, it was detected 4 agricultural drought periods (2060- 2062, 2072-2074, 2092-2094 and 2095-2097). The severity distribution maps were prepare for the determined agricultural drought periods in the basin. It should be taken precautions in time against the water deficit that will occur in agricultural drought periods which may occur in Konya Closed Basin. In addition, losses in agricultural production should be minimized by preparing water management plans. Measures to be taken to reduce drought effects will directly contribute to the regional producer and contribute to the production and economy of the country.

Experimental study on local fuel–coolant interaction in molten pool with different melts

In a Core Disruptive Accident (CDA) of Sodium-cooled Fast Reactor (SFR), by supposing rather pessimistic condition, a large molten fuel pool would be possibly formed that contains enough fuel with the potential to exceed prompt criticality due to fuel compactive motion. Local fuel-coolant interaction (FCI) in the molten pool is identified as one of the typical inducing factors that may result in such compactive motion. To understand the characteristics of this interaction, owing to the PMCI (Pressurization characteristics in Melt-Coolant Interaction) facility recently established at the Sun Yat-sen University, in our earlier publications two series of simulated experiments, i.e. Coolant-Injection (CI) experiments and Melt-Injection (MI) experiments, have been conducted, in which water and low-melting-point Bi-Sn-In alloy (60% Bi, 20% In and 20% Sn) were used respectively as the simulant materials for sodium and molten fuel. In this study, aimed at checking the generality of the experimental findings as well as achieving further enhanced understanding on this interaction, a large number of experiments are newly performed through delivering water into a simulated molten fuel pool comprised of Lead-Bismuth Eutectic (LBE) alloy (another low-melting-point alloy). Through detailed comparisons (with the CI-mode experiments using Bi-Sn-In alloy), it is found that a similar trend in the transient pressure and temperate history as well as the overall effect of experimental parameters (such as water quantity, melt and water temperature, water-lump shape and melt depth) on the pressurization characteristics can be reproduced for the new LBE experiments. Despite a much lower thermal diffusivity, for the LBE experiments it is confirmed that the most likely reason resulting in the limited pressurization as water volume increases should be also primarily owing to the isolation effect of vapor bubbles generated at the melt-water interface. Possibly due to the enhanced melt density which facilitates the penetration of melt through vapor bubbles, under the same parametric condition the pressurization in LBE experiments is generally much higher than that in Bi-Sn-In experiments. Compared to melt static pressure, the pressurization under different melt depths is supposed to be more influenced by the varied easiness of melt penetration. Current work provides a large amount of favorable experimental database and insight for promoted understanding on actual CDAs and improved verifications of SFR severe accident codes in China.

Posthuman Knowledge

Posthuman Knowledge