[en] A computer program, GUARD, semi-implicit multi-dimensional two-fluid three equations hydraulic solver, is formulated and coded. The essential steps of the formulation are presented. Numerical tests are performed to confirm its applicability and/or to identify any potential problems. Some suggestions are made to improve the convergence and stability of the scheme

[en] The KIRAP-UNCUT code was developed for performing uncertainty analysis that is one of significant PRA tasks. The purpose of the paper is to verify this code using a statistical approach of Kolmogrov-Smirnov goodness-of-fit test. In conclusion, we can not find any statistical evidence of significant difference in performance of the code, compared with others (IMSL subroutine, LHS)

[en] Based on the Euler beam theory and the elastic strain energy method, the elastic stiffness formula of the holddown spring assembly consisting of several leaves is derived. To check the validity of the formula, the elastic stiffness from the formula is compared with that from the characteristic test on several kinds of specimens of leaf springs. As a result of comparisons, it is found that the formula could predict the elastic stiffness of the holddown spring assembly below the inherent error range of the formula. And also, the frictional effects on the elastic stiffness are also quantitatively investigated

[en] The primary function of a Radiation Monitoring System is the detection and measurement of radioactive materials released in gaseous or liquid effluent streams of nuclear power plants. The purpose of this paper is to suggest the alarm and warning set point for Radiation Monitoring System

[en] A four-story reinforced concrete frame building model is designed for the gravity loads only. Static nonlinear pushover analyses are performed in two orthogonal horizontal directions. The overall capacity curves are converted into ADRS spectra and compared with demand spectra. At several points the deformed shape, moment and shear distribution are calculated. Based on these results limited ductility seismic design concept is proposed as an alternative seismic design approach in moderate seismicity resign

[en] Filtration of a dodecane-SDS emulsion was studied in a stirred ultrafiltration cell. Dodecane-SDS emulsion formed a gel layer and was mostly rejected by the membrane(PM-30). Ultrafiltration experiments were performed in a batch cell under various operating conditions. The characteristics of the gel layer and other relevant parameters of the model were estimated. It was observed that the steady-state flux was independent of pressure

[en] The reliability of the friction pairs in the primary major components is important to the safety and performance of the reactor. The bearings and friction pairs of the main coolant pump (MCP) and the control element drive mechanism (CEDM) for the integral reactor SMART are operated for very long period in the high temperature primary coolant. In this paper, the design features of the tribological couples in the MCP and CEDM are presented and plans for the friction and wear tests are established in order to justify the selected bearing materials

[en] In May 1999, IAEA issued Medium Term Strategy. The strategy takes a one house approach on the basis of the Agency's mandate : technology, safety and verification. As the strategy forms a valid basis for the Agency's work, it will affect significantly the establishment of detailed cooperation between the Agency and Member States. This paper analyzed the contents of the strategy by its goals and examined responses from Member States. Also the paper provides the measures to make the most of the strategy

[en] The difficulty of neutron transport in radiation shielding is to find the fair degree of performance. The radiation shielding is the major role in the calculation of health physics, medical physics, and nuclear facilities. Several Variance Reduction Techniques are compared. The Survival Biasing (SB) and Russian Roulette (RR) can improve the time saving and simple calculations. The newly introduced exponential transform function, Local Importance Function Transform (LIFT), increases the Figure of Merit factor (FOM). This means time saving is developed. These methods are tested for the spherical fuel in the High Temperature Gas-cooled Reactor (HTGR)

[en] The primary function of containment structure is to provide a leak-tight barrier around the reactor system to limit any inadvertent release of radioactive or hazardous effluents into the environments. Therefore, the containment structure is designed to have structural integrity specified in ASME Code and lately after TMI-2 accidents, considerations for severe accidents are required on a regulatory basis. In this study, the regulatory guides of severe accidents were analyzed, the containment of nuclear power plant was evaluated accordingly and was confirmed to maintain a reliable leak-tight barrier under severe accident conditions