[en] On the basis of already performed site selection activities for low- and intermediate level radwaste (L/ILW) repository in Croatia, two preferred sites are expected to be included into the Physical plan of Croatia. Thus, they both will become available for performance of detailed field investigations aimed to find out all necessary characteristics relevant for safe disposal of L/ILW. Since past researches were based on evaluation of available site specific data obtained by explorations for other purposes, foreseen site investigations are assumed to be extremely important for decision making of final L/ILW repository site. In other words, existing data on geomorphology, geology, seismicity, hydrology, pedology, meteorology and demography of preferred sites should be carefully re-evaluated and checked up through the triad of site investigations: (1) detailed geological fieldwork (including geological mapping); (2) geophysical surveys, and (3) core drilling and logging. Site characterisation will be supported by interpretation of remote sensing data. Accepted land use planning documents will be fully respected. The article shads more light to safety related site specific characteristics of both preferred sites. (author)

[en] For many years radium sources were used for various applications in medicine and industry. Due to their undesirable characteristics, almost all of these sources have been replaced by more modern sources. Storage of these unused sources, especially in developing countries, is often inadequate. Conditioning of radium sources for proper storage is one of major objective of the Waste Technology Section of IAEA. The conditioning of the spent radium sources in Croatia was performed by a specially trained team from the Austrian Research Center Seibersdorf, under contract to the IAEA, using an IAEA developed and approved procedure. The source conditioning took place in a waste storage and treatment facility at the Rudjer Boskovic Institute, Zagreb, Croatia. The conditioning of the national radium stock in Croatia was performed within the period from 13-17 October 1997. The total inventory was 1316 mg (298 sources, 49 GBq). The sources were mainly needles and tubes. All spent radium sources were conditioned in 25 small capsules and one large capsule. The capsules were put into three shielding devices and two packages (drums) were produced. The total activity/shield is still under the transportation regulation limit. No complications in this operation were experienced. The operation caused no contamination and hence no decontamination was required. (author)

[en] LET dependence of highly sensitive Al₂O₃:C (made in Russia) and CaF₂:Mn (made in Slovenia) TL dosimeters was investigated using low (gamma) and high LET (alpha, neutron) exposures. Glow curve analysis was used to determine the efficiencies of TL light production for alpha particle and neutron irradiation relative to gamma exposure. The experiments were performed with ⁶⁰Co, ²⁴¹Am and ²³³Pu-Be source using a 20 cm diameter polyethylene moderator. The irradiation dose was in the range 1-40 mGy for gamma and alpha irradiations and 1-40 mSv for neutron irradiation, respectively. Neither high temperature peak, nor significant change of the glow curve shape were found after irradiation by high LET radiations. Both detectors showed a linear response of TL signals in the dose range used. Gamma sensitivity of Al₂O₃:C as compared to CaF₂:Mn was 6:1. Relative TL efficiency for alpha particle irradiation as compared to gamma exposure was about 0.03 and 0.18 for Al₂O₃:C and CaF₂:Mn, respectively. Neutron sensitivity was found to be similar (about 0.04 as compared to gamma irradiation) for both materials. Results indicate that for both materials investigated the TL sensitivity decreases with increasing LET, moreover their glow curves do not possess peaks for selective assessment of low and high LET radiation dose separately. The relative high TL efficiency of CaF₂:Mn for alpha particle irradiation and the unexpected split of its peak in two components suggests to plane further investigations to determine the effect of proton irradiation as well. (author)

[en] An issue everyone of us is nowadays trying to define is how to interpret the agreement and the messages from Kyoto. Opinions differ, from those which dispute the impacts of energy use in relation to climate change, to enthusiasm that some proper steps have finally been undertaken in limiting and directing both the social and energy sector development according to the concept of sustainable development and environmental protection. We hope that Forum will be another step in considering the role of Kyoto and in defining how each one of us, each company, each local community, each country and all of us together through international institutions could succeed in giving Kyoto its rightful dimension. Such a dimension would prompt technological development, the creation of a high-quality legislation, changes in the ways of thinking considering energy and environmental management, improvements in education and availability of information

[en] When Slovenia gained its independence in 1991, its energy sector was characterised by largely centralised state planning and artificially low prices maintained by widespread subsidies. Supply side considerations tended to dominate the energy policy and sectoral planning. As a result the final energy intensity in Slovenia was (still albeit declining) considerably higher than the EU average. In order to support economic growth and transition to a modern market economy, integrated and competitive in the European and world market structures, the National Assembly of the Republic of Slovenia adopted a resolution on the Strategy of Energy Use and Supply of Slovenia in early 1996. In the field of energy use, the long-term strategic orientation is to increase energy efficiency in all sectors of energy consumption. The main objective can be summarised as to secure the provision of reliable and environmentally friendly energy services at least costs. In quantitative terms the Strategy attaches a high priority to energy efficiency and environmental protection and sets the target of improving the overall energy efficiency by 2% p.a. over the next 10 to 15 years. To achieve the target mentioned above the sectoral approach and a number of policy instruments have been foreseen. Besides market based energy prices which will, according to the European Energy Charter, gradually incorporate the cost of environment and social impacts, the following policy instruments will be intensified and budget-supported: education and awareness building, energy consultation, regulations and agreements, financial incentives, innovation and technology development. The ambitious energy conservation objectives represent a great challenge to the whole society. (author)

[en] The Kyoto Protocol set industrialised nations' targets for cutting emissions of greenhouse gases, and promoted the so called flexible international market mechanisms to support those cuts, i.e. international emissions trading, joint implementation and clean development mechanisms. Greenhouse policy instruments should be environmentally effective, economically rational, equitable in allocation of emission rights, and politically feasible. Because of major uncertainties about both future damages and costs of global warming, it is advisable to start with low-cost and less radical mitigation measures, but to apply them in as many countries as possible. In time, according to the new findings, those measures could be replaced by more radical and more expensive ones (the so-called 'broad, then deep' strategy). Domestic climate change mitigation measures could be implemented only with an effective international agreement in place. One of the domestic measures could be CO₂ emission charge, since it would increase the costs of fossil-fuelled plants and make them less competitive relative to other supply options, particularly to the zero-carbon nuclear option. The largest barriers to progress in dealing with climate change are domestic political obstacles and international institutional challenges. (author)

[en] As the energy production plays a significant role in global greenhouse emissions, the reduction possibilities have to be carefully evaluated. Taking into account the projected increase in the global energy consumption, it is obvious that only the nuclear option offers the possibility for the expected economic growth in underdeveloped countries and transition countries accompanied by significant carbon dioxide emission reduction. The possibilities for carbon dioxide emission reduction in Croatia resulting from the nuclear option acceptance are presented in this paper. Fossil fuel consumption projections are given as well as associated carbon dioxide emissions. Possible carbon dioxide emissions decrease which would be a result of substituting fossil fuel energy by nuclear energy are calculated and discussed. It is demonstrated that the value of the carbon dioxide emission set by the Kyoto Protocol could be met only in case of introducing three nuclear power plants into the Croatian power system. (author)

[en] Specific requirements to nuclear power units for small-size and medium-size electricity grids are under consideration. Among the main requirements are as follows: compliance of power unit output with the grid stability, enhanced NPP reliability and safety, competitiveness of the power generated. As it is shown in the report, Simplified Vessel-type Boiling Water Reactors (SVBWR) meet the totality of the requirements imposed on. Design and main characteristics of SVBWR-type VK-300 reactor and two-unit NPP with such reactors being developed by RDIPE are described. VK-300 and NPP safety problems including ones for underground NPP layout are under consideration. (author)

[en] Multilateral international agreements have defined the framework of behavior and cooperation in various fields and aspects of peaceful use of nuclear energy. Thus, obligations have been defined in the following areas: nonproliferation of nuclear weapons, physical protection of nuclear material, liability for nuclear damage, nuclear safety, early notification about a nuclear accident and assistance in case of nuclear accident. Obligations regarding radioactive waste management should be defined soon. This paper gives a review of obligations from particular agreements with a special emphasis on those which are being realized through mutual cooperation of concerned countries and are important for safe use of nuclear energy. (author)

[en] The paper describes the use of system code RELAP5/mod2 in analysis of inadvertent closing of the main steam isolation valve that happened in NPP Krsko on September, 25 1995. Three cases were calculated in order to address different aspects of the modelled transient. This preliminary calculation shows that, even though the real plant behaviour isn't completely reproduced, such kind of analysis can help to better understand plant behaviour and to identify important phenomena in the plant during transient. The result of the calculation for the case no. 3, indicates that, with better understanding of status of the plant systems, calculated results could be very similar to the plant data. (author)