Hark-Rho Kim

OPPORTUNITIES AND CHALLENGES OF NEUTRON SCIENCE AND TECHNOLOGY IN KOREA

Neutron science and technology, the utilization of neutron beams for a wide variety of scientific and engineering research ranging from materials and life science to industrial applications, has been one of the key elements of modern science and technology. Currently, the neutron science and technology in Korea is in rapid growth with the operation of the 30 MW High-flux Advanced Neutron Application Reactor (HANARO) at the Korea Atomic Energy Research Institute, which is one of the most powerful nuclear research reactors in the world. Furthermore, a state of the art HANARO cold neutron research facility, which will open a new era for the neutron science and technology in Korea, is expected to become available in 2010. In this paper, the progress of neutron science and technology in Korea is reviewed and its unprecedented new opportunities and challenges in coming years are presented.

CHARACTERISTICS OF A NEW PNEUMATIC TRANSFER SYSTEM FOR A NEUTRON ACTIVATION ANALYSIS AT THE HANARO RESEARCH REACTOR

A rapid pneumatic transfer system (PTS) for an instrumental neutron activation analysis (INAA) is developed as an automatic irradiation facility involving the measurement of a short half-life nuclide and a delayed neutron counting system. Three new PTS designs with improved functions were constructed at the HANARO research reactor in 2006. The new system is composed of a manual system and an automatic system for both an INAA and a delayed neutron activation analysis (DNAA). The design and basic conception of a modified PTS are described, and the functions of system operation and control, radiation protection and emissions of radioactive gas are improved. In addition, a form of capsule transportation of these systems is tested. The experimental results pertaining to the irradiation characteristics with variation of the neutron flux and the temperature of the irradiation position with the irradiation time are presented, as is an analysis of the reference material for analytical quality control and uncertainty assessments.

Present situations and perspectives on the advanced utilization of HANARO

Abstract Since HANARO reached its initial criticality on the 8th of February, 1995, this facility has been improved and enhanced continuously in two ways. The first way is to check and review every function of its systems in order for the reactor to be operated with more improved performance as well as with the design values of the reactor. The second one is to equip most suitable instruments with convenient facilities to enhance the utilization program of the reactor. In the first case, we are starting the research work for the improvement of fuel performance and developing aluminum plugging in vertical holes of reflector tank for the reduction of thermal neutron loss due to light water. For the development of fuel, tubular type of fuel is considered to maximize the thermal margin, and a uranium–molybdenum (U–Mo) fuel specimen is planned for irradiation test in the HANARO. U–Mo fuel is proved to accommodate higher uranium loading density in the fuel meat and thus the use of the U–Mo fuel brings about the room for the on-site spent fuel storage pool in the HANARO. In the second case, Neutron Spectrometers are in scheduled installation according to users’ requirements. A new pool cover is being designed to accommodate driving mechanisms for the neutron transmutation doping facility and capsule facility on the cover. In addition to these, a special research fund is allocated from the government to encourage researchers, who utilize the reactor for their research purposes.

Current status of the 40 m small-angle neutron scattering instrument development at the HANARO research reactor

The cold neutron research facility project at the Korean HANARO research reactor was launched in 2003. A state-of-the-art small-angle neutron scattering instrument was selected as a top-priority instrument. An analytical calculation was used to obtain the optimum instrument design and the appropriate range of scattering vectors of the instrument. Then, in order to optimize the instrument layout and to enhance the instruments performance, a Monte Carlo simulation was performed. The Q range [where Q is the magnitude of the scattering vector given by (4π/λ)sin(θ/2), θ is the scattering angle and λ is the wavelength] of the instrument will extend from 0.0008 to 1.0 A−1. The instrument layout was optimized based on simulation results. The maximum flux at the sample position can reach about 5.5 × 10 7 n cm−2 s−1.

Study of the effect of nano-sized precipitates on the mechanical properties of boron-added low-carbon steels by neutron scattering techniques.

The effect of nano-sized precipitates on the mechanical properties of boron-added low-carbon steels was studied by neutron scattering techniques such as powder diffraction, small-angle scattering and particle tracking autography.