The decommissioning of nuclear power plants (NPPs) is rapidly increasing because NPPs are not only no longer profitable in many cases but are also being decommissioned due to a lack of public acceptance or political reasons in many countries, particularly in Europe, following the explosion of the Fukushima Daiichi NPP. Accordingly, a significant body of research has focused on achieving safe, environmentally sound, and sustainable decommissioning in many countries where there is demand for NPP decommissioning. In order to achieve sustainable decommissioning that restores the NPP site to its pre-NPP environmental state, it is necessary to understand the safety, technology, and cost aspects as well as having the process and strategy to systematically promote them. Although there are a limited number of countries with experience and knowledge in the management of decommissioning multiple NPPs, researchers in countries just starting NPP decommissioning need diverse research information on how to formulate a sustainable decommissioning strategy as well as related factors. In particular, a systematic review of decommissioning strategies, such as DD, ID, and ET, and the influencing factors associated with each strategy is needed from the researcher’s point of view. In this regard, this study reviews the research literature on decommissioning strategies for nuclear power plants with a sustainable perspective. A systematic method involving a meta-analysis is used. The results of this study confirm that many researchers are most interested in DD and are dealing with ID and ET at the same level, but in reality, DD and ID are being adopted at similar rates. Thus far, only three ETs have been adopted in the United States. Most countries that have adopted ID are deemed to have been influenced by political decisions.

A technology has been developed to produce low-cost high-quality FCP (free-form concrete panel) using materials such as glass and pulp. However, FCP production and installation should meet required schedules in order for such technological development to be applied in practice. If it is not possible for the production to satisfy the installation schedules, sufficient lead time should be granted; otherwise, an additional 3D plastering machine is required. This then would give rise to cost and time conflicts. Therefore, an analysis on processes and influential factors relating to FCP production-installation is necessary after which algorithms should be created to link these processes and factors in a systematic method. This study is aimed at production planning of free-form concrete panels using 3D plastering technology. For the purpose of this study, an influential factor analysis and production planning shall be performed in a phased approach. The results of this study are expected to be used as a crucial reference in developing models that can simulate FCP productioninstallation in various ways.

In general, rebar cutting waste is estimated to be 3-5% in the construction planning stage. However, technology to reduce RCW was not developed at the construction field, so more than 5% is generated in the actual construction. To solve this problem, many studies was conducted to minimize RCW. Most studies proposed methods to minimize RCW by using stock lengths or market lengths, referred to as standard. In other words, the rebar shown in the structural drawings is combined using the rebar mill or the stock length held to minimize cutting waste. RCW can be reduced if rebars ordered in special lengths are used in rebar combinations. Reducing rebar cutting wastes to near-zero rebar are necessary in terms of cost reduction and sustainable construction. Therefore, the purpose of this study is a basic study of near-zero rebar cutting waste management by adjusting lap splice position. As a result, the optimal amount of rebars in the case site was 17.74 tons, with the rebar cutting waste ratio reduced to less than 1%. In addition, the amount of rebar was reduced by 0.53 tons, which is 2.93% of the actual quantity. About 284 USD was saved, and 1,872 kg-CO2 was reduced.

When using concrete to produce exterior finishing panels of free-form building structures, different panel shapes make it difficult to reuse the forms. This results in increased formwork cost as well as a significant amount of embodied CO2 (ECO2) generation. Through years of research, we have developed a free-form panel (FCP) production technique engaging the 3D plastering technique (3DPT) without using conventional plywood forms. When 3DPT becomes available for free-form building projects, a great deal of ECO2 reduction effects is expected in addition to reduced time and cost in FCP production. The purpose of this study is to prove this by analyzing ECO2 reduction effects achieved through sustainable FCP production using 3DPT. The study involved project case selection, calculation of resources consumed for conventional plywood forms, and analysis of the reduction effects. As a result, it was demonstrated from the case project that 1196 tons of CO2 were reduced using 3DPT, accounting for approximately 99% of the amount produced from conventional plywood forms (CPF). The study findings will be used as a basic reference for sustainable production of FCPs ensuring speed and precision in production as well as innovative ECO2 reduction effects.