The purpose of this study is to provide technical issues in upgrade and modification of fuel handling equipment at operating nuclear power plants. The improvement for safety function and performance enhancement of fuel handling equipment has been going on for 20 years since the early 2000’s. This improvement is recently focused on the replacement of components through the performance analysis and the operation and maintenance plan based on replacement cycle of its component. Additionally, it is required to secure spare parts so that it can be operated at all times with compatibility and standardization to other domestic nuclear power plants. The fuel handling equipment is consisted of refueling machine, upender and carriage of fuel transfer system, spent fuel handling machine, new fuel elevator and various tools, and the equipment are linked in systematic interlocks. Fuel handling is a critical task during a nuclear power plant refueling outage. Even minor component defects may stop operation of the whole system and have a significant impact on the overall system process. To achieve this goal, major components that are expected to be replaced for reliable operation are summarized as follows; 1) motor assembly with AC servomotors and driver for bridge, trolley and hoist of refueling machine and spent fuel handling machine, 2) winch motor and drive for upender and carriage of fuel transfer system, 3) operator control console with a HMI PC base PLC (Programmable Logic Controller) control system, 4) positioning and load weighing sensors such as an encoder and a load cell with its support for periodic calibration and maintenance, 5) main power drapped style festoon cable assembly for bridge of refueling machine, 6) pneumatic control assembly for gripper operation of refueling machine, 7) active components (e. g., air motor, hydraulic cylinder and limit switch) to be removable and reinstallable without requiring the water level to be lowered. It is advisable to utilize such various information as it can help to improve reliability of fuel handling as a critical path in upgrade and modification of fuel handling equipment at operating nuclear power plants.

HANARO(High Flux Advanced Neutron Application Reactor) design was started from 1985 and was constructed in 1995 by KAERI(Korea Atomic Energy Research Institute). The document control book was written by hand and hard-copy was kept at that time. JRTR(Jordan Research and Training Reactor) was contracted for export to Jordan March 2010 by KAERI Consortium. This contract is a matter for congratulation of export of first made-in-Korea nuclear system. NRR(New Research Reactor) officially launched in April 2012. The document control system is controlled by PPM (Project Procedure Manual) and QAP(Quality Assurance Procedure) and ANSIM(KAERI Advanced Nuclear Safety Information Management) was built for JRTR. ANSIM system consists of the document management holder, document container holder and organization management holder. This system was registered about 2,000 design output like DDA(Document Distribution for Agreement), design documents, design drawings and project manger memorandum. The system design for JRTR was smoothly performed using ANSIM. NRR set to separated exclusive system that was based on JRTR ANSIM. Folder of nuclear laws, codes and standards was added to that system and those will be useful during designing. The project and quality assurance plans and procedures has been managed from design documents separately. Above all things, independent review and ALARA(As Low As Reasonably Achievable) review were operated for nuclear safety at ANSIM. And cover and body of design document were combined and backup system was established. After then, system upgrade and operation pursue the effect analysis by design change for accomplishment of the research reactor project.

Dynamic Positioning System(DPS)은 그 신뢰성 및 redundancy(대체) 시스템에 따라 IMO 및 각 선급에서 3개의 class(등급)로 나 누고 있다. IMO MSC/Circ 645에 의하면 DPS는 Class 1, 2, 및 3로 나누고 있으며 등급이 높을수록 좀 더 신뢰성 있고 안전하게 DP 선박을 운용할 수 있다. 국내에서 많은 DP Class 선박들이 건조되고 있는 상황에서 DP Class 1선박의 개조를 통해서 DP Class 2로 변경하거나 DP Class 2선박을 신조 또는 중고선으로 구입하는 경우 무엇을 검토하고 확인해야 하는지에 대한 구체적인 실무 자료가 부족하고, DP Class 1 선박을 Class 2로 변경하여 다시 매도하는 새로운 산업분야의 개척에 있어 국내 사례를 바탕으로 한 연구가 필요할 것으로 판단된다. 이에 본 연구에서는 DP Class 1선박을 DP Class 2 선박으로 변경하기 위해서는 어떠한 IMO 및 선급의 DP class 요건의 충족이 필요하며 이를 위해 서 어떠한 설비의 변경 및 추가가 필요한지를 국내에서 있었던 실제 사례를 통해서 연구해 보았다. DP 선박 Class 변경을 위해서는 FMEA를 통해서 파악되는 DP 선박의 동력 시스템, thruster 시스템 및 제어 시스템 3가지의 주요 시스템에 대체(redundancy)기능을 갖추어야 한다. 동 력 시스템은 단일의 발전기, 배전반등에 문제가 발생해도 DP 기능을 유지할 수 있어야 하며, 더불어 PMS기능을 갖추고 있어야 한다. thruster 시스템은 단일의 고장이 발생하더라도 선박의 Surge, Sway 및 Yaw를 남은 thruster 시스템으로 자동 제어 할 수 있어야 한다. 각종 제어 시스템, PRS 및 센서는 여러개를 설치하여 단일의 장비고장에도 DP 기능을 유지 할 수 있어야 한다.