The adoption of renewable energy technologies in developing nations is recognized to have positive environmental impacts; however, what are their effects on the electricity supply chain workers? This article provides a quantitative analysis on this question through a relatively new framework called social life cycle assessment, taking Malaysia as a case example. Impact assessments by the authors show that electricity from renewables has greater adverse impacts on supply chain workers than the conventional electricity mix: Electricity production with biomass requires 127% longer labor hours per unit-electricity under the risk of human rights violations, while the solar photovoltaic requires 95% longer labor hours per unit-electricity. However, our assessment also indicates that renewables have less impacts per dollar-spent. In fact, the impact of solar photovoltaic would be 60% less than the conventional mix when it attains grid parity. The answer of “are renewables as friendly to humans as to the environment?” is “not-yet, but eventually.
Sustainability 2019, 11(5), 1370
The authors conducted a quantitative reevaluation of the short-term Japanese plutonium balance forecast until 2040 with a new numeric model, in the aim of contributing to the policymaking toward the stable US-Japan alliance as well as the East Asian region. The Japanese nuclear fuel cycle was replicated as a system dynamics model on Stella with officially available statistical data. The Monte Carlo method was used to estimate the range of the capacities of Japanese nuclear power plants until 2040. The simulation results showed the peak accumulation of plutonium in Japan would be observed around 2025. This indicates that while the plutonium imbalance in Japan would be a point of concern for the next five years, the situation will likely mitigate. Consequently, even if lowering the capacity of Rokkasho reprocessing plant were to be possible, it would not make a significant difference if it takes more than five years. As a result, the authors conclude that if we were to hurry the resolution of the current Japanese plutonium imbalance issues, the Japanese government has to either consider to limit the restarting of NPPs to newer plants or to cut the operation rate of Rokkasho reprocessing plant from the first year.
Kyoto University Graduate School of Economics Discussion Paper Series No. E-18-002
Link Model, a participatory rural appraisal (PRA) programme for micro-infrastructure construction funding aid, has received much attention in Bangladesh over the last few decades. This study aims to contribute to the latest phase of the Link Model project, launched in July 2016 by the Bangladeshi government. To this end, the authors conducted a field survey in Kalihati Upazila, which involved 102 villagers and 153 local representatives. The authors used the survey to examine the efficacy of the programme and to identify the key factors that contribute to its success. Results obtained from the questionnaire survey showed that the programme had high degrees of satisfaction and penetration in the surveyed villages. Moreover, the degree of satisfaction was unaffected by gender, religion, income or education background, which is notably consistent with the ideals of PRA. Villagers who understood the policy better were more satisfied with the micro-infrastructures developed through the Link Model programme. The ratings of union development officers (UDO) strongly correlated with the number of micro-infrastructures. Therefore, this study concludes that the key success factors of Link Model are (a) the understanding of villagers on the programme for quality and (b) the capability of UDO for quantity.
Journal of Development Policy and Practice, Vol 3, Issue 2, 2018: 191-214
The authors constructed a dynamic simulation model of a nuclear fusion power plant on Modelica language to obtain fundamental knowledge on the plasma control requirements for the future commercial fusion power plants. The fusion power plant model was designed with a 1500-MW thermal output tokamak reactor with He-cooled Li2TiO3 solid breeder blanket (coolant outlet conditions: 8 MPa and 515.8 °C). A superheated Rankine cycle was designed to achieve the electrical output of 485.38 MW with the operating pressure of 20.5 MPa. Two plasma output patterns, a step decrease of power and a single pulse decrease of power, were simulated to assess the response of the power plant. A sudden step decrease in fusion neutron led to an immediate decrease in the blanket temperature and the first coolant temperature. In order to avoid the sharp temperature drop, a need for a turbine bypass mechanism or a He coolant boiler bypass mechanism was indicated. On the other hand, because of the delay in the plant responses, the deviation of the electrical output from steady state could be minimized by recovering the plasma output in few tens of seconds. Based on the findings, a new diagram was presented that illustrates an important plasma control requirements for future commercial fusion power plants.
IEEE Transactions on Plasma Science ( Volume: 46 , Issue: 5 , May 2018 )
The authors propose nuclear biomass gasification plant as an advancement of conventional gasification plants. Environmental impacts of both fission & fusion plants were assessed through life cycle assessment. The result suggested the reduction of green-house gas emissions would be as large as 85.9% from conventional plants, showing a potential for the sustainable future for both fission & fusion plants.
2017 International Congress on Advances in Nuclear Power Plants, Fukui and Kyoto; Japan; 24 April 2017 through 28 April 2017; Code 131581
This study analyzed adverse effects of fusion plants on the stability of small-scale grids through simulation-based case studies. Major frequency fluctuations were observed in the event of a plant start-up and a sudden interruption of fusion electric output power, as represented by plasma disruption, suggesting difficulties in fusion plant installation to majority of countries in the future. To mitigate the adverse effects, a fusion plant combined with an energy storage was proposed and evaluated. The results indicated that large energy storage like pumped-hydro storage could successfully reduce the frequency deviations to the acceptable range. An innovative offshore pumped-hydro storage, marine inverse dam, is also discussed in this paper.
Fusion Science and Technology, Volume 68, Issue 2, 2015: 341-345