[en] A task force team was made up to establish the design and test requirements of the fuel test loop(FTL) which will be installed in HANARO. The activities of the task force team include the review of the performance of the FTL, the establishment of user requirement, the review of interface between HANARO and FTL, the reevaluation of design concept and finally the provision of the viable design option through the impact analysis on design change. Based on the review, the task force team has finalized the design concept of the in-pile test section(IPS) which accommodates a maximum number of 7 fuel pins. Following the modification of the IPS, we have identified the required design modification of the out-file system(OPS) to reduce the investment cost FTL facility while maintaining the performance and not jeopardizing the safety of system. The result of the analysis will be used for the design change of both IPS and OPS system of FTL and for the future works of the project. (author). 30 tabs., 104 figs

[en] Hot cell and related facilities were developed in the RI production building of the HANARO. 1. development of concrete H/C and related components 2. development of lead H/C and related components 3. development of the hydraulic transfer system 4. development of radiation monitoring system 5. development of purification system for Co-60 storage pool 6. development of the fire fighting system for H/C 7. development of the experimental equipment. (author). 15 figs

[en] The HANARO, a multi-purpose research reactor of 30 MWth, open-tank-in-pool type, has been under normal operation since its initial criticality in February, 1995. The HANARO is composed of inlet plenum, grid plate, core channel with flow tubes and chimney. The reactor core channel is located at about twelve meters (12 m) depth of the reactor pool and cooled by the upward flow that the coolant enters the lower inlet of the plenum, rises up through the grid plate and the core channel and comes out from the outlet of chimney. A guide tube is extended from the reactor core to the top of the reactor chimney for easily un/loading a target under the reactor normal operation. But active coolant through the core can be quickly raised up to the top of the chimney through the guide tube by a jet flow. This paper describes an analytical analysis that is the study of the flow behavior thourgh the guide tube under reactor normal operation and unloading the target. As results, it was conformed through the analysis results that the guide jet is suppressed under the top of the chimney after modifiving the orifice diameter of 37.5 mm to 31 mm

[en] It has been observed in HANARO that fuel assemblies have mechanical damages on some components due to the flow-induced vibration in the fuel channels. The major damages were the fretting wear on the bottom end plates and spacer plates of the fuel assemblies. Both the components are made of aluminum but may cause the fretting wear on the corresponding surfaces of the zirconium fuel channels. Also the bottom guide arms (zirconium) and top springs of the fuel are considered to be major parts that cause the wear on the fuel channels. Therefore, the inspection of the inner surfaces of the fuel channels was required from the lifetime point of view. It is very difficult and time-consuming work to remove and install the fuel channels because of its inherent characteristics and the physical interference with other components in the reactor core. Thus we developed special tools for the inspection of the fuel channels by using an impression material without the removal of the reactor components. The impression material is a compound to replicate the damages of the fuel channels within a limited working time considering the hardening time as well as radiation effect. The special tool called wear inspection tool is a mechanical equipment to press the impression compound against the inner walls of the fuel channels where the components of the fuel assemblies contact. The inspection tool has respectively 30 molding cups (5 levels x 6 cups each level) that are operated in radial direction by turning the central rod with a fuel-handling tool. The wear-inspection had been successfully accomplished for three fuel channels. The result shows visible wear marks on a hexagonal flow tubes at the positions corresponding to fuel components such as the top and bottom guide. The wear damage is slight (approximately 0.2mm depth) in comparison with the thickness of the flow tube (1.6mm). No visible wear mark was found in the cylindrical flow tubes so far. The wear inspection is being continued for all the remaining fuel channels to get the valuable results for the estimation of lifetime of the flow tubes. The results would be helpful also for the design improvement of the fuel assemblies

[en] The results of the research on the NTD automatic control techniques started from the beginning of 2001. The motor control system is designed to operate with independent and simultaneous up-down and rotation of the silicon ingot motion and the setpoint of each motor speed could be easily adjusted by the control PC. Taking a few steps of field test, its performance has been successfully verified. Then, through the actual irradiation with the real silicon ingot under 24MW of reactor power, it has been confirmed that the motor control system developed could be applied to the commercial production. Two set of Rh-type SPNDs, known as a in-core neutron detector are used for real-time monitoring of the accumulated neutron irradiation. They are installed around the center position of the irradiation sleeve and the cables are carefully routed up to the top of the pool for connection to the DC amplifier. It has been verified, by the sample irradiation test for validation of the design that the neutron measurement system gives an accurate and stable signal, which shows a good consistency with the estimation. To precisely control the target fluence, the NTD control program has been designed so that the silicon ingot be automatically removed from its irradiation hole by the pre-defined irradiation time or accumulated neutron flux. Data acquisition program has been also developed for real-time monitoring and analysis of the analog signals, like SPND flux, control rod position and reactor power. The actual position of the silicon ingot is fedback from the motor control system via the digital communication port then used as a reference signal for the data analysis. It's been proved that a few times of sample irradiation tests under real condition that the NTD control software and the data acquisition program works satisfactorily and can be used for the commercial service next year

[en] The design requirements for the power distribution, standby power supply, and raceway system were established for the conceptual design of electrical system in 2004. To complete a guide for the design of entire electrical system of the advanced HANARO reactor(AHR), the design requirements for the remaining building electric service system were developed in 2005. The building service system consists of lighting, communication, grounding, security, fire detection and alarm, etc. to provide comfort, safe, and convenient environment

[en] The HANARO seismic monitoring system consists of five field sensors and one monitoring panel. The field sensors are composed of three triaxial accelerometers wihch installed at base slab, free field and overhead crane support respectively, one seismic trigger and one seismic switch. The most parts of panel except field sensors are not produced any more, so the counterplan is to be needed. The present panel system is not only out-of-date model but dependent upon foreign technology. We drive to begin home production of panel system in order to break from foreign technology. We improve the analog Seismic Monitoring System(SMS) with magnetic tape recorder into digital Seismic Monitoring and Analysis System(SMAS) except five field sensors. After the installation of SMAS, we have carried out the Site Acceptance Test(SAT) to confirm the requirements of technical specification for fabrication as following. 1. Test of power supply modules and UPS supplying the power to monitoring panel and field sensors 2. Integrity test of VME Module and interface card 3. Software verification and validation - data acquisition, analysis algorithm and its application, data handling 4. Check the interface between monitoring panel and field sensors 5. Integration test of hardware, software and field sensors. We confirm that the performance of SMAS conforms the technical specification for fabrication of SMAS as a consequence of SAT and this new system can be in normal operation. If the earthquake occurs, this system will analyze, evaluate and save the seismic data at the same time, so that the reactor operator will begin to tackle efficiently and promptly. This report describes the composition of the improved SMAS and the result of SAT

[en] A Failed Fuel Detection System(FFDS) by monitoring gamma rays in the primary cooling pipe has been installed and used in HANARO. It has been confirmed, from 6 years of operating experience that N-16, a dominant gamma radiation of primary coolant adversely affect an efficient detection of fuel failure. As an alternative for improving the current points in issue and ensuring effective failed fuel detection, a delayed neutron measuring concept was suggested. The new concept was proved to be excellent in its performance through 2 years of experiment and analysis. As a result of the successful completion of the feasibility study, implementation of the delayed neutron channel has been required as a trip parameter for reactor protection system. Since the FFDS is used for a trip parameter of the reactor protection system, a class 1E device satisfying the safety design and manufacturing requirements specified in the codes and standards has been installed. The performance of the delayed neutron channel has been verified under the actual power operation and also the compatibility with the existing gamma channels was properly checked. Having been proved by the field application test to be much more sensitive than the previous system in fuel failure detection, the new FFDS will improve reactor safety. An additional effect is expecting by using the previous gamma channel for monitoring abnormal radiation in the primary coolant

[en] An advanced research reactor is being designed since 2002 and the conceptual design has been completed this year for the several types of core. Also the fuel was designed for the potential cores. But the process system, the I and C system, and the electrical system design are under pre-conceptual stage. The conceptual design for those systems will be developed in the next year. Design requirements for the electrical system set up to develop conceptual design. The same goals as reactor design - enhance safety, reliability, economy, were applied for the development of the requirements. Also the experience of HANARO design and operation was based on. The design requirements for the power distribution, standby power supply, and raceway system will be used for the conceptual design of electrical system

[en] As a supplementary structure supporting the irradiation facilities, the in-chimney bracket holds guide tubes whose holding position in CT or IR is the middle part of the instrumented facility between the hole spider and the robot arm already provided in the reactor pool liner. Also, the bracket grips the upper part of the guide tubes when it is applied to hold the instrumented facility loaded in OR sites. The irradiation test will be successfully conducted since this bracket reduces the flow-induced vibration (FIV) and the dynamic response to seismic load. The installation position of the bracket is 60 cm below the top of the chimney, i.e., thermo siphoning hole position. To evaluate the structural integrity on the in-chimney bracket and the related reactor structures, ANSYS finite element analysis model is developed and the dynamic characteristics are analyzed. The seismic response analyses were performed for the in-chimney bracket and the related reactor structures of HANARO under the design earthquake response spectrum loads of OBE and SSE. The analysis results show that the stress values in main points of reactor structures and in-chimney bracket for the seismic loads are also within the ASME code limits. It is also confirmed that the fatigue usage factor is much less than 1.0. Therefore any damage on structural integrity is not expected when the in-chimney bracket is installed at the upper part of the reactor chimney. This bracket had been designed and manufactured based on the dimensions of the as-built chimney. In the process of design and preliminary installation, chimney measurement tools, dummy chimney, and installation tools were developed and the installation procedure was prepared and verified through the installation rehearsal