Kori unit 1 and Wolsong unit 1 were permanently shut down in 2017 and 2019, respectively. Both plants were decided to demolish the building without reuse. Large structures must be demolished after removing systems and components in the building, and in the case of large structures, thorough planning is required because of the large scale of work. Therefore, in this study, important considerations in the phase of the demolition plan of large structures when decommissioning were analyzed. The demolition of large structures at nuclear facilities is major one phase of work within a broader decommissioning plan. Furthermore, the actual demolition of the structure (i.e., physical process) represents the last step in a process that begins with extensive planning and analysis. The National Demolition Association (NDA) has provided checklist items that should be considered before the start of a commercial demolition project and/or in the bid process. Important Considerations in the Phase of the demolition plan of large structures when decommissioning of nuclear facilities are Site knowledge and programs, Engineering survey/demolition plan, Hazardous and radioactive materials, Open air demolition, Financial and project management, Permits, Code adherence, and Special programs, Disposal pathway, Final site condition. The results of this study can be used as a basis for the Planning large structures demolition of the Kori unit 1 and Wolsong unit 1.

In this research, the dynamics equations for a demolition fire vehicle were formulated. This was done by developing an interface that allows co-simulation using ADAMS and MATHEMATICA. In this study, MATHEMATICA alone was used to calculate the constrained dynamics equations, to demonstrate the impact force and the constraint Jacobian of the end-effector as any desired location through the x, y and z axes. Then we mathematically derived a model for a unilaterally constrained multi-link. Assumptions about the fire demolition vehicle of the constraint coordinate and the impact issues of the model are discussed in the next sections. The estimation procedure for the dynamics equation showed good approximation results in terms of solving a reaching task problem.

Korea Research Reactor 1&2 (KRR-1&2), Korea’s first research reactor, began dismantling in 1997. As of 2022, the demolition of general areas such as offices has been completed, and contaminated areas such as reactor rooms remain. On the other hand, construction waste generated in contaminated areas of nuclear facilities cannot be disposed of as general industrial waste. It is predicted that about 5,000 tons of construction waste will be generated if the contaminated area of KRR-1&2 is demolished. In this study, the application plan for the demolition of contaminated area of KRR-1&2 was reviewed through a review of laws and cases related to domestic and overseas disposal. The only method for disposing of construction waste in contaminated areas that can be applied in Korea is clearance in accordance with Nuclear Safety Commission Notice No. 2020-06. In addition, there has been no case of demolishing large-scale nuclear facilities in Korea. Therefore, there are limitations in domestic laws and standards to be applied to the dismantling of contaminated areas of KRR-1&2. The IAEA and the United States specify comprehensive matters such as optimization of radiation protection and minimization of waste products. The EU recommends demolition after decontamination by removing contaminated areas before demolition of buildings. It also presents three options for reuse, recycling, and disposal of buildings and building waste. In particular, in the case of Germany, detailed radioactivity measurement methods for deregulation of buildings and building waste are presented in accordance with the EU’s guidelines. As a result of synthesizing this, it is judged that the EU and Germany building clearance plan will be suitable for domestic application.

도심지나 문화재가 인접한 지역 등의 소음, 진동 등 기존 발파해체 공법이 제한적인 조건에서 사용할 수 있는 구조물 해체 공법으로 무소음화학팽창제(soundless chemical demolition agent, SCDA)를 이용한 공법이 있다. 그러나 SCDA의 사용에 대한 기준이나 가이드라인에 참고될 만한 연구는 미미한 실정이다. 이 연구에서는 실내실험을 수행하여 강관의 길이, 외부수분차단, 수화열 발산 등의 다양한 조건에 따른 SCDA의 팽창압 발현 특성을 확인하였다. 또한 SCDA의 최소요구팽창압 예측을 위한 해석모델(자유단 1면, 고정단 3면의 직사각형 모델)을 개발하고 주요변수해석(홀 간 거리, 콘크리트 압축강도)을 수행하였다. 이 연구의 해석결과를 활용하여 자유단으로부터 콘크리트 구조물의 박락을 효과적으로 유도할 수 있을 것으로 판단된다.

As an alternative to conventional explosive methods for demolition of concrete structures and rocks, the use of non-explosive demolition agents can be considered to reduce noise, vibration, and dust emissions during the demolition process. In this study, we conduct finite element analysis for crack initiation and propagation caused by the expansion of non-explosive demolition agents in square concrete structures. The predicted crack patterns are compared with the experimental results in the literature. The minimum values of the required expansion pressure of non-explosive demolition agents are also estimated, which depend upon the arrangement of non-explosive demolition agents and empty holes. Furthermore, we investigate the effect of empty holes on the fragmentation of concrete structures, and discuss the effective arrangement of non-explosive demolition agents and empty holes for fragmentation improvement.

해양암반이나 구조물 해체를 위한 전통적인 방법은 다이나마이트를 이용한 발파공법, 잭해머(Jackhammer)를 이용한 공법이다. 이러한 방법은 소음이나 폭발의 위험등으로 인해 사용에 많은 제약이 따른다. 이런 제한된 상황에서 사용할 수 있는 무소음화학팽창제(SCDA)의 사용이 증가하고 있는 추세이다. 그러나 무소음화학팽창제의 사용에 관한 규격이나 설계 및 시공에 대한 제안서는 현재 전무한 상황이다. 따라서 본 연구에서는 다양한 조건(구조물의 구속, 천공홀의 크기, 천공홀의 수 등)에서 콘크리트 구조물에 균열이 생성, 진전될 수 있는 최소요구팽창압을 예측하였다.

In this paper, the forward and inverse kinematics equations for demolition fire vehicle with 6-DOF were developed. This was done through the development of an interface that allows co-simulation using MATHEMATICA and ADAMS. The implementation of this project was done entirely in MATHEMATICA by calculating the kinematics equations to demonstrate the usefulness of this product. The forward and inverse kinematics of the demolition fire vehicle represents the position and orientation of the end-effector as any desired location. This research was particularly conducted using the simulator, and it showed good approximation results in terms of solving a reaching task problem.

In this paper, a commercial multibody dynamics program ADAMS was utilized to investigate the model for the multi-joint boom conflicts. In this process, CATIA, ANSYS and ADAMS were used to develop the simulation. The addition of ADAMS made the system more accurate and improved precision of the system. In brief, the 3D CAD model of the structure was initially developed via CATIA. After this, the CATIA models were exported to ANSYS for creating flexible-body modeling by using formatted file. Subsequently, with ADAMS, the flexible body model was directly imported from ANSYS which performed the analyses of the dynamic collision of the nozzle boom conflicts. This contained the information regarding geometry and model shapes of the flexible body. Using ADAMS/Durability, it was possible to determine the strain energy for the nozzle configuration by crashing the contact structure that was created. Via this procedure, the acquired simulation analysis of nozzle showed interestingly good results with respect to the objectives of the study

As fires have frequently occurred with large scale at cultural assets and warehouses, the development of Korean type demolition fire apparatus for efficient fire fighting becomes important. In this study, structural stability is investigated for assembly model of boom and outrigger by using computational structural analysis. Analysis results of boom and outrigger unit are also compared with assembly model. As this study result, equivalent stress result of boom unit is about 6% higher than assembly model and equivalent stress result of outrigger unit is about 15% higher than assembly model.

In this paper, our aim is to develop a simulation model for Multi-joint demolition water vehicle. 3D model of vehicle is developed with CATIA. The rigid simulation model is built in ADAMS and the flexible simulation models are developed using ADAMS and ANSYS. The combination of the both ADAMS and ANSYS can improve the precision of system simulation. The rigid model with rigid multi-slide booms and rigid refracting booms, the hybrid model with flexible multi-slide booms and rigid refracting booms, and a flexible model with flexible multi-slide booms and flexible refracting booms are considered. The simulation analysis shows a good performance, and valuable results we are interested in are obtained.