06 Electrical power supply and utilization (scientific, technical)

The paper presents reliability and risk analysis of the RBMK-1500 reactor accident localization system (ALS) (confinement), which prevents radioactive releases to the environment. Reliability of the system was estimated and compared by two methods: the conventional fault tree method and an innovative dynamic reliability model, based on stochastic differential equations. Frequency of radioactive release through ALS was also estimated. The results of the study indicate that conventional fault tree modelling techniques in this case apply high degree of conservatism in the system reliability estimates. One of the purposes of the ALS reliability study was to demonstrate advantages of the dynamic reliability analysis against the conventional fault/event tree methods. The Markovian framework to deal with dynamic aspects of system behaviour is presented. Although not analysed in detail, the framework is also capable of accounting for non-constant component failure rates. Computational methods are proposed to solve stochastic differential equations, including analytical solution, which is possible only for relatively small and simple systems. Other numerical methods, like Monte Carlo and numerical schemes of differential equations are analysed and compared. The study is finalized with concluding remarks regarding both the studied system reliability and computational methods used.

05101033 On-line monitoring of instrument channel performance in nuclear power plant using PEANO Fantoni, P. F. et al. Progress in Nuclear Energy, 2003, 43, (1-4), 83-89. On-Line monitoring evaluates instrument channel performance by assessing its consistency with other plant indications. Industry and EPRI experience at several plants has shown this overall approach to be very effective in identifying instrument channels that are exhibiting degrading or inconsistent performance characteristics 'On-Line Moni- toring of Instrument Channel Performance by EPRI (2000)'. On-Line monitoring of instrument channels provides information about the condition of the monitored channels through accurate, more frequent monitoring of each channel 's performance over time. This type of performance monitoring is a methodology that offers an alternate approach to traditional time-directed calibration. On-line monitoring of these channels can provide an assessment of instrument perform- ance and provide a basis for determining when adjustments are necessary. Elimination or reduction of unnecessary field calibrations can reduce associated labour costs, reduce personnel radiation exposure and reduce the potential for miscalibration. PEANO 'A Neuro-Fuzzy Model Applied to Full Range Signal Validation of PWR Nuclear Power Plant Data by Fantoni (2000)' is a system for on-line calibration monitoring developed in the years 1995-2000 at the Institutt for energiteknikk (IFE), Norway, which makes use of Artificial Intelligence techniques for its purpose. The system has been tested successfully in Europe in off-line tests with EDF (France), Tecnatom (Spain) and ENEA (Italy). PEANO is currently installed and used for on-line monitoring at the HBWR reactor in Halden. This paper describes the results of performance tests on PEANO with real data from a US PWR plant, in the framework of a co-operation among IFE, EPRI and Edan Engineering, to evaluate the potentials of PEANO for future installations in US nuclear plants.

05/01034 Potentials of hydrogen and nuclear towards global warming mitigation-expansion of an integrated assessment model MARIA and simulations Mori, S. and Saito, T. Energy Economies, 2004, 26, (4), 565-578. This paper describes an extended version of an integrated assessment model called Multi-regional Approach for Resource and Industry Allocation (MARIA) and how it was applied to assess the global and regional greenhouse gas (GHG) emission mitigation policies. The model has been developed to assess the potential contribution of fossil, biomass, nuclear and other energy technologies and land-use changes to future GHG emissions. In this paper, the MARIA model is extended to evaluate a new hydrogen production process through s team- methane reforming at a significantly lower temperature (300-500°C) than that of conventional s team-methane reforming processes as a liquid fuel supplier under the long-term global warming strategies. Bern simple carbon cycle model is also included in the model to reflect the recent findings in climate science. The simulation results suggest that hydrogen with Fast Breeder Reactors could supply 5-8 GTOE of hydrogen in the second half of the 21st century when climate policy that stabilizes the atmospheric carbon concentration is introduced. Although biomass does not completely replace fossil energy sources, the simulations show that it effectively mitigates the marginal cost of carbon emission.

05101035 Public participation in EIA of nuclear power plant decommissioning projects: a case study analysis Bond, A. et al. Environmental Impact Assessment Review, 2004, 24, (6), 617-641. Over the coming years a large number of nuclear power plants (NPP) will be decommissioned as they reach the end of their operational life and the decommissioning proposals will be subjected to Environmental

158 Fuel and Energy Abstracts May 2005

Impact Assessment (EIA). At present, experience of decommissioning is extremely limited and three detailed reviews were conducted of the public participation experiences associated with this activity in three European Union countries (Germany, Spain and the United Kingdom) to try to identify elements of good practice, which could be carried forward to future decommissioning projects. For each of the case studies, information was gathered using a combination of review of the Environmental Statement, site visits and interviews with key personnel identified by the study team. The information collected pointed to five 'success factors', which could be used to summarize the main aspects of good practice to carry forward. These can be categorized as: authority acceptance of the value of participation; integration of all participation activities under tile umbrella of EIA; carrying out participation activities before final strategies are adopted; keeping the decision- making process transparent; and providing sufficient information to the public to facilitate participation. A further review of public partici- pation experiences in the literature covering 13 contentious projects provides support for these success factors.

05101036 Real time reactor noise diagnostics for the Borssele (PWR) nuclear power plant Barutgu, B. et al. Progress in Nuclear Energy, 2003, 43, (1-4), 137-143. After the upgrade of Borssele NPP in 1997, core cycle 24, the power plant operated 3 years more with 91% availability. The authority of the power plant decided to enhance and upgrade the reactor trend monitoring and plant information recording system with higher frequencies than the plant data processing system (PPS) as well as installing a flexible and multiple-purpose reactor noise analysis system which may support the reactor maintenance group with on-line and off- line capabilities for several different signal processing applications. Two measuring and monitoring systems were built in 2001 and fully taken in implementation during the start-up of the new core 28. In this sense, the new system was used in power operation during the 29th of September 2001. This paper will introduce the measuring system, the operational tasks, and the results obtained so far on the real-time core- barrel motions (CBM) and the two-primary coolant pump vibrations measured through the reactor noise analysis.

05•01037 Thresholds and goals for safety performance indicators for nuclear power plants Saqib, N. and Siddiqi, M. T. Reliability Engineering & System Safety, 2005, 87, (2), 275-286. Performance indicators have found a wide use in the nuclear industry. IAEA developed a safety performance indicators framework for use by NPPs. Karachi Nuclear Power Complex (KNPC) worked, under the auspices of IAEA, on developing guidelines for establishing goals and thresholds, aggregation to higher levels and trend indexes. This paper describes the work done by KNPC on goals and thresholds along with the recommended guidelines.

06 ELECTRICAL POWER SUPPLY AND UTILIZATION

Scientific, technical

05/01038 Investigation on gasoline deep desulfurization for fuel cell applications Zhang, J. C. et al. Energy Conversion and Management, 2005, 46, (1), 1- 9. The effect of adding some amounts of cerium into Zn-Fe-O/AI203 sorbent on its performance of removal of organic sulfur compounds from gasoline by adsorption was studied in this paper. It showed that the ideal compositions for the preparation of Zn-Fe-Ce-O/AI203 consisted of 4.54 wt.% ZnO, 2.25 wt.% FezO3 and 2.5 wt.% CeOz, respectively, shortened as AZFC0.s2. Further study indicated that this sorbent could be well regenerated at 250°C with gas mixtures containing 6.0 vol.% steam + air and 2400 ml h 1 ml-1 gas space velocity. At those regenerated conditions and 60°C adsorption temperature, the AZFC0.s2 sorbent had better desulfurization stability, which was confirmed by typical characterization results using BET, XRD and SEM apparatus. This implied that the AZFC0.s2 sorbent could be an ideal sorbent for removal of organic sulfur compounds from gasoline.