Hyo-Jik Lee

Design of remotely operated vol-oxidizer for hot-cell application

A high-capacity vol-oxidizer which can handle a several hundred kgHM/batch is being developed to supply U3O8 powders to an electrolytic reduction reactor. In this paper, we deal with the development of remotely operated vol-oxidizer that can convert UO2 pellets to U3O8 powders for hot-cell application. In order to develop this remotely operated vol-oxidizer, we proposed a design process and modular design for the remote operation in hot-cell, and the device has been modified by these modular design points and the design drawings have been presented. The design process consists of steps such as a mechanism device design, an engineering design and thermal analysis. To design the main mechanisms of the 1st step, we evaluated various mechanical (slitting, ball mill, roller straightening) and chemical methods (muffle furnace, rotary kiln). In the engineering design of the 2nd step, we calculated required volumes according to various weights and lengths of rod-cuts to design the reactor size. In the 3rd step, by using the modeling and analysis SWs (SolidWorks, COSMOSWorks), we built a 3D-modeling and performed an analysis of the main mechanisms for the safety design. We have selected the target modules of this devices such as heater, utility, motor, reactor, valve and outlet. The remote assembling and disassembling possibilities of the selected modules have been analyzed from the viewpoints of visibility, interference, approach, weight, and so on. We presented finally modular design suited to the above viewpoints.

Analysis of the Remote Operation in a Digital Mockup of the Advanced Spent Fuel Conditioning Process

Spent nuclear fuel is a high radioactive material and is handled in the hot cell. The ACP equipment is operated in intense radiation fields as well as in a high temperature. Thus, the equipment is operated in a remote manner and should be designed with a consideration for a remote handling and maintenance. Also a suitable remote handling technology needs to be developed along with the design of the process concepts. In this paper, the remote operation of the advanced spent fuel conditioning process (ACP) is analyzed by using 3D graphic simulation tools. For this we developed a digital mockup (DM), which provides the capability of verifying the remote operability of the ACP with the virtual equipment. In other words, by applying a virtual reality to a remote maintenance operation, a remote operation task can be simulated in the DM, not in the physical mockup, that is a real environment. The graphic simulator will substantially reduce the cost of the development of the remote handling and maintenance procedure as well as the process equipment, while at the same time developing a remote maintenance concept that is more reliable, easier to implement, and easier to understand.

Equipment Layout Improvement for Large-Scale Hot Cell Facility Logistics

This study presents approaches to equipment layout improvement for a large-scale hot cell facility. First, the original facility layout and target process are introduced, including the basic information and specifications. Second, the flow of process materials is analyzed and the relationships are evaluated in detail using a “from-to chart” and a “relationship chart” for the original layout, and the logistics are simulated using the selected discrete event simulator to calculate the traveling distances of process materials handled by teleoperated material handling systems. Third, the original layout is modified using the total closeness rating (TCR), and the efficiency and usage of the material handling system are calculated and compared with the original case to evaluate the efficiency improvement of the modified layout. This modification process, which included load reduction, enabled those aspects of the material handling system that would need to be changed to be identified; these changes were suggested by a quantitative analysis of the logistics between each pair of stations and intuitive rearrangement based on charts and figures. These approaches could be an initial step in the large-scale hot cell design process, with future work to follow.

A haptic device interface for the operation of the virtual arm

The remote operation in nuclear facilities is essential field since human access is restricted due to the effects of high radiation. Using a haptic device in the roll of a master manipulator enhances the throughput and the reliability of the simulation because of the kinetic sense of reality. This paper describes a 3D graphic based simulator system to simulate the nuclear facilities. The human interface of a virtual arm using a haptic device is proposed to improve the reality during the remote operation of the apparatuses in virtual nuclear facilities. The results of experiments of virtual arm operation in a virtual nuclear facility with the haptic device are evaluated in this paper.

Designing a simulator for use in the Pyroprocessing

In this paper, we describe the design of a simulator for use in Pyroprocessing technology development. This simulator is a virtual facility of a Pyroprocessing mock-up facility to be constructed later. The simulator will be designed to include all the Pyroprocessing equipment, utilities, remote maintenance and handling devices and auxiliary devices or tools, in the form of virtual models which are necessary for the Pyroprocessing technology implementation in a virtual facility environment. It will provide an efficient means for simulating and verifying the conceptual design, design developments, arrangements, and rehearsal of the Pyroprocessing equipment from the viewpoint of remote operation and maintenance by use of its various virtual functions. It will also enable the trial and simulation of the Pyroprocessing technologys development in a virtual process environment in advance. We present the current status of the simulator development and also demonstrate a case study of the simulator performed in its current development stage.

Spent Nuclear Fuel Disposal and Recycling Process and Its Operational Experience

Korea Atomic Energy Research Institute (KAERI) has been developing an advanced spent fuel conditioning process (ACP) to reduce the volume of spent fuel, and the construction of an ACP facility (ACPF) for a demonstration of its technical feasibility has been completed. In 2006 two inactive demonstrations were performed with simulated fuels in the ACPF. Accompanied by process equipment performance tests, its remote operability and maintainability were also tested during that time. Procedures for remote operation tasks are addressed well in this study and evaluated thoroughly. Also, remote maintenance and repair tasks are addressed regarding some important modules with a high priority order. The above remote handling tests results provided a lot of information such as items to be revised to improve the efficiency of the remote handling tasks. This paper deals with the current status of the ACP in Korea and the progress for remote handling in the ACPF.

Development of a Bridge Transported Servo Manipulator System for the Remote Operation and Maintenance of Advanced Spent Fuel Conditioning Process

The Advanced Spent Fuel Conditioning Process(ACP), which is the process of the reduction of uranium oxide by lithium metal in a high temperature molten salt bath for spent fuel, was developed at Korea Atomic Energy Research Institute (KAERI). Since the ACP equipment is located in an intense radiation field (hot cell) as well as in a high temperature, it must be remotely operated and maintained. The ACP hot cell is very narrow so the workspace of the wall-mounted mechanical Master-Slave Manipulators(MSMs) is restricted. A Bridge Transported Servo Manipulator(BTSM) system has been developed to overcome the limitation of an access that is a drawback of the mechanical MSMs. The BTSM system consists ot a bridge crane with telescoping tubeset, a slave manipulator, a master manipulator, and a control system. We applied a bilateral position-position control scheme with friction compensation as force-reflecting controller. In this paper, the transmission characteristics on the tendon-and-pulley train is numerically formulated and analyzed. Also, we evaluate the performance of the force-reflecting servo manipulator.

Parameter Identification of Robot Hand Tracking Model Using Optimization

In this paper, we present a position-based robot hand tracking scheme where a pan-tilt camera is controlled such that a robot hand is always shown in the center of an image frame. We calculate the rotation angles of a pan-tilt camera by transforming the coordinate systems. In order to identify the model parameters, we applied two optimization techniques: a nonlinear least square optimizer and a particle swarm optimizer. From the simulation results, it is shown that the considered parameter identification problem is characterized by a highly multimodal landscape; thus, a global optimization technique such as a particle swarm optimization could be a promising tool to identify the model parameters of a robot hand tracking system, whereas the nonlinear least square optimizer often failed to find an optimal solution even when the initial candidate solutions were selected close to the true optimum.