degree of public acceptance to a reduction in the EPZ area and to identify the means of implementing the simplification of EPZ that would be most acceptable to the public.

04•02782 Safe trapping of Cs in heat-treated zeolite matrices Bosch, P. et al. Journal of Nuclear Materials, 2004, 324, (2-3), 183-188. Cesium retention performances of two different natural zeolites (an Italian phillipsite-rich tuff and a Mexican erionite-rich tuff), pre- exchanged in Cs form and heat-treated, are compared. After thermal treatment at 1000°C both zeolites satisfactorily retain Cs during back- exchange tests with NaC1 solution or by a prolonged contact with distilled water. The different mechanisms of Cs encapsulation are elucidated. The Cs-exchanged phillipsite, a less siliceous and less heat- stable zeolite, tends to form pollucite on heating. Potlucite is a naturally occurring mineral phase that contains and irreversibly traps cesium. The Cs-exchanged erionite tends to form an amorphous phase on heating and Cs is immobilized through glass formation.

04•02783 The control system of KSTAR Kwon, M. et al. Fusion Engineering and Design, 2004, 7l, (1M), 17-2i. The Korea Superconducting Tokamak Advanced Research (KSTAR) is a medium size, fully superconducting tokamak, which is scheduled to begin operation in year 2006. The control system of KSTAR consists of a supervisory system, plasma control system, and local control systems for various subsystems. Modular system, high reliability, flexibility and long time maintainability are major factors for the system design. The EPICS is the first choice for the distributed system control and the MDSPlus will be utilized for the data handling and analysis. The reflective memory network will be used for the real time plasma control. A pilot system has been being developed with VME and Compact PCI buses. Current status of the development of KSTAR control system wi[ll be presented.

04•02784 The development of grain-face porosity in irradiated oxide fuel White, R. J. Journal o f Nuclear Materials, 2004, 325, (1), 61-77. The predominant mode of fission gas release occurs through atomic diffusion to the grain boundaries. In oxide fuels the fission gases initially precipitate as an array of small lenticular bubbles of circular projection. The arrival of additional gas and vacancies causes these bubbles to grow and coalesce into fewer, larger bubbles. Depending on the irradiation conditions and temperatures, these bubbles may develop either as circular lentieular pores or as extended multi-lobed pores. Eventually the pores may intersect the grain edges where pathways may be formed which enable the gas to migrate to the outer geometry of the fuel and hence to the gap and the pin free volume. Recent extensive PIE campaigns on irradiated fuels have provided a large database of inter-granular porosity development and, from these, models of bubble growth, coalescence, morphological relaxation and venting have been developed.

04/02785 Uncertainties in control rod worth in a damaged reactor core Williams, M. M. R. Annals of Nuclear Energy, 2004, 31, (9), 1073-1081. Some comments are made about the effective worth of a control plate in a reactor that has sustained structural damage. The damaged core is modelled using a statistical description based on the source-sink method. Detailed quantitative results are presented for a plate reactor and a major conclusion is that, on average, randomness reduces the effective worth of a control element.

Economics, policy, supplies, forecasts

04/02786 Current status and future prospects of the JT-60U control system Yonekawa, I. et al. Fusion Engineering and Design, 2004, 71, (1-4), 11- 15. The JT-60U control system, composed of a UNIX-based workstation and a VME-bus system, has been successfully performing advanced plasma control for the JT-60U plasma discharges. Various hardware modifications and advanced plasma control algorithms have been continuously integrated into the JT-60U control system since its upgrade in 1991. The ZENKEI, the supervisory control system, has been entirely converted from its original 16-bit minicomputers and CAMAC system to the combination of a workstation and VME-bus system linked through an Ethernet network. The plasma equilibrium control system utilizes a full VME-bus system composed of three DEC alpha CPU modules that are currently running at control cycle times of 250 gs. The parameters for plasma equilibrium control are calculated by a newly developed real-time plasma shape calculation and

06 Electrical power supply and utilization (scientific, technical)

reconstruction system. These parameters are fed to the plasma equilibrium control system synchronized by 250-~as clock pulses. To progress toward the advanced plasma control concept, which includes adoption of a global plasma parameter control algorithm and suppression of MHD instabilities, improvements were extensively consolidated into the plasma control system (PCS). Currently, additional modifications of the JT-60U control system have extended the pulse duration of the discharge without a major change in JT-60 equipment.

04•02787 Development of automated operating procedure system using fuzzy colored petri nets for nuclear power plants Lee, S. J. and Seong, P. H. Annals o f Nuclear Energy, 2004, 31, (8), 849-869. In this work, AuTomated Operating Procedure System (ATOPS) is developed. ATOPS is an automation system for emergency operation of a nuclear power plant (NPP) and it can monitor signals, diagnose statuses, and generate control actions according to corresponding operating procedures without any human operator's help. Main functions of ATOPS are an anomaly detection function and a procedure execution function but only the procedure execution function is implemented in this work because this work is just the first step. In the procedure execution function, operating procedures of NPPs are analysed and modelled using Fuzzy Coloured Petri Nets (FCPN) and executed depending on decision making of the inference engine. In this work, ATOPS prototype is developed to demonstrate its feasibility and it is also validated using the FISA-2/WS simulator. The validation is performed for the cases of a loss of coolant accident (LOCA) and a steam generator tube rupture (SGTR). The simulation results show that ATOPS works correctly in the emergency situations.

04•02788 Trends in computing systems for large fusion experiments How, J. A. et al. Fusion Engineering and Design, 2004, 70, (2), 115-122. The major European fusion facilities, JET, Tore Supra and Asdex Upgrade, have a 30-year history from conception to the present day. This period has seen a rapid evolution in computer techniques. Experience has shown that IT architectures and standards adopted early in the construction phase of a project are carried into the main programme and affect the project for its entire lifetime. In this paper, the authors select a few of the more important computer-related lessons that they have learned in Europe, particularly with respect to the EFDA-JET facility, and they make recommendations towards the next generation of machines.

06 ELECTRICAL POWER SUPPLY AND UTILIZATION

Scientific, technical

04•02789 A novel fuzzy-logic-based phase selection technique for power system relaying Youssef, O. A. S. Electric Power Systems Research, 2004, 68, (3), 175- I84. Fast tripping and consequent single-pole auto-reclosure of the faulted phase for single-phase earth faults is extensively used in long line applications. Traditional phase selection techniques can suffer some drawbacks due to their dependency on varying system and fault conditions. However, with the advent of fuzzy-logic techniques, and their ability to map complex and non-linear power system configur- ations provide a very attractive solution to accurate and fast phase selection procedure. This paper presents a new approach to real-time phase selection in power transmission systems using fiazzy-logic-based multi-criteria approach. Only the three line currents are utilized to detect the faulted phase. An online wavelet-based pre-processor stage is used with 10 samples data window (based on 4.5 kHz sampling rate and 50 Hz power frequency). The author demonstrates the multi- criteria algorithm that is based on fuzzy sets for the decision making part of the scheme. Computer simulation has been conducted using EMTP programs. Results proved that the correct detection is achieved in less than half a cycle and that computational burden is simpler than the recently postulated phase selection techniques, and this approach can be used as an effective tool for high-speed digital relaying.

Fuel and Energy Abstracts November 2004 395